310 results on '"Samuel, CS"'
Search Results
2. Placebo comparator group selection and use in surgical trials: the ASPIRE project including expert workshop
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David J Beard, Marion K Campbell, Jane M Blazeby, Andrew J Carr, Charles Weijer, Brian H Cuthbertson, Rachelle Buchbinder, Thomas Pinkney, Felicity L Bishop, Jonathan Pugh, Sian Cousins, Ian Harris, L Stefan Lohmander, Natalie Blencowe, Katie Gillies, Pascal Probst, Carol Brennan, Andrew Cook, Dair Farrar-Hockley, Julian Savulescu, Richard Huxtable, Amar Rangan, Irene Tracey, Peter Brocklehurst, Manuela L Ferreira, Jon Nicholl, Barnaby C Reeves, Freddie Hamdy, Samuel CS Rowley, Naomi Lee, and Jonathan A Cook
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placebo control ,rct ,surgery ,invasive ,procedure ,ethics ,Medical technology ,R855-855.5 - Abstract
Background: The use of placebo comparisons for randomised trials assessing the efficacy of surgical interventions is increasingly being considered. However, a placebo control is a complex type of comparison group in the surgical setting and, although powerful, presents many challenges. Objectives: To provide a summary of knowledge on placebo controls in surgical trials and to summarise any recommendations for designers, evaluators and funders of placebo-controlled surgical trials. Design: To carry out a state-of-the-art workshop and produce a corresponding report involving key stakeholders throughout. Setting: A workshop to discuss and summarise the existing knowledge and to develop the new guidelines. Results: To assess what a placebo control entails and to assess the understanding of this tool in the context of surgery is considered, along with when placebo controls in surgery are acceptable (and when they are desirable). We have considered ethics arguments and regulatory requirements, how a placebo control should be designed, how to identify and mitigate risk for participants in these trials, and how such trials should be carried out and interpreted. The use of placebo controls is justified in randomised controlled trials of surgical interventions provided that there is a strong scientific and ethics rationale. Surgical placebos might be most appropriate when there is poor evidence for the efficacy of the procedure and a justified concern that results of a trial would be associated with a high risk of bias, particularly because of the placebo effect. Conclusions: The use of placebo controls is justified in randomised controlled trials of surgical interventions provided that there is a strong scientific and ethics rationale. Feasibility work is recommended to optimise the design and implementation of randomised controlled trials. An outline for best practice was produced in the form of the Applying Surgical Placebo in Randomised Evaluations (ASPIRE) guidelines for those considering the use of a placebo control in a surgical randomised controlled trial. Limitations: Although the workshop participants involved international members, the majority of participants were from the UK. Therefore, although every attempt was made to make the recommendations applicable to all health systems, the guidelines may, unconsciously, be particularly applicable to clinical practice in the UK NHS. Future work: Future work should evaluate the use of the ASPIRE guidelines in making decisions about the use of a placebo-controlled surgical trial. In addition, further work is required on the appropriate nomenclature to adopt in this space. Funding: Funded by the Medical Research Council UK and the National Institute for Health Research as part of the Medical Research Council–National Institute for Health Research Methodology Research programme.
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- 2021
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3. Development of Novel High-Affinity Antagonists for the Relaxin Family Peptide Receptor 1
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Hossain, MA, Praveen, P, Noorzi, NA, Wu, H, Harrison, IP, Handley, T, Selemidis, S, Samuel, CS, Bathgate, RAD, Hossain, MA, Praveen, P, Noorzi, NA, Wu, H, Harrison, IP, Handley, T, Selemidis, S, Samuel, CS, and Bathgate, RAD
- Abstract
H2 relaxin is a peptide hormone that exerts its biological actions through the G protein-coupled receptor, RXFP1. The numerous important biological functions of H2 relaxin, including potent renal, vasodilatory, cardioprotective, and anti-fibrotic actions, have resulted in considerable interest in its use as a therapeutic for various cardiovascular diseases and other fibrotic indications. Interestingly though, H2 relaxin and RXFP1 have been shown to be overexpressed in prostate cancer, allowing for the downregulation or blocking of relaxin/RXFP1 to decrease prostate tumor growth. These findings suggest the application of an RXFP1 antagonist for the treatment of prostate cancer. However, these therapeutically relevant actions are still poorly understood and have been hindered by the lack of a high-affinity antagonist. In this study, we chemically synthesized three novel H2 relaxin analogues that have complex insulin-like structures with two chains (A and B) and three disulfide bridges. We report here the structure-activity relationship studies on H2 relaxin that resulted in the development of a novel high-affinity RXFP1 antagonist, H2 B-R13HR (∼40 nM), that has only one extra methylene group in the side chain of arginine 13 in the B-chain (ArgB13) of H2 relaxin. Most notably, the synthetic peptide was shown to be active in a mouse model of prostate tumor growth in vivo where it inhibited relaxin-mediated tumor growth. Our compound H2 B-R13HR will be an important research tool to understand relaxin actions through RXFP1 and may be a potential lead compound for the treatment of prostate cancer.
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- 2023
4. The single-chain relaxin mimetic, B7-33, maintains the cardioprotective effects of relaxin and more rapidly reduces left ventricular fibrosis compared to perindopril in an experimental model of cardiomyopathy
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Alam, F, Gaspari, TA, Kemp-Harper, BK, Low, E, Aw, A, Ferens, D, Spizzo, I, Jefferis, A-M, Praveen, P, Widdop, RE, Bathgate, RAD, Hossain, MA, Samuel, CS, Alam, F, Gaspari, TA, Kemp-Harper, BK, Low, E, Aw, A, Ferens, D, Spizzo, I, Jefferis, A-M, Praveen, P, Widdop, RE, Bathgate, RAD, Hossain, MA, and Samuel, CS
- Abstract
The hormone, relaxin (RLX), exerts various organ-protective effects independently of etiology. However, its complex two-chain and three disulphide bonded structure is a limitation to its preparation and affordability. Hence, a single chain-derivative of RLX, B7-33, was developed and shown to retain the anti-fibrotic effects of RLX in vitro and in vivo. Here, we determined whether B7-33 could retain the other cardioprotective effects of RLX, and also compared its therapeutic efficacy to the ACE inhibitor, perindopril. Adult male 129sv mice were subjected to isoprenaline (ISO; 25 mg/kg/day, s.c)-induced cardiomyopathy, then s.c-treated with either RLX (0.5 mg/kg/day), B7-33 (0.25 mg/kg/day; equivalent dose corrected for MW) or perindopril (1 mg/kg/day) from days 7-14 post-injury. Control mice received saline instead of ISO. Changes in animal body weight (BW) and systolic blood pressure (SBP) were measured weekly, whilst cardiomyocyte hypertrophy and measures of vascular dysfunction and rarefaction, left ventricular (LV) inflammation and fibrosis were assessed at day 14 post-injury. ISO-injured mice had significantly increased LV inflammation, cardiomyocyte hypertrophy, fibrosis, vascular rarefaction and aortic contractility in the absence of any changes in BW or SBP at day 14 post-injury. Both B7-33 and RLX equivalently reduced LV fibrosis and normalised the ISO-induced LV inflammation and cardiomyocyte hypertrophy, whilst restoring blood vessel density and aortic contractility. Comparatively, perindopril lowered SBP and the ISO-induced LV inflammation and vascular rarefaction, but not fibrosis or hypertrophy. As B7-33 retained the cardioprotective effects of RLX and provided rapid-occurring anti-fibrotic effects compared to perindopril, it could be considered as a cost-effective cardioprotective therapy.
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- 2023
5. Anti-inflammatory and anti-fibrotic effects of berberine-loaded liquid crystalline nanoparticles
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Chakraborty, A, Paudel, KR, Wang, C, De Rubis, G, Chellappan, DK, Hansbro, P, Samuel, CS, Dua, K, Chakraborty, A, Paudel, KR, Wang, C, De Rubis, G, Chellappan, DK, Hansbro, P, Samuel, CS, and Dua, K
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- 2023
6. The Placental NLRP3 Inflammasome and Its Downstream Targets, Caspase-1 and Interleukin-6, Are Increased in Human Fetal Growth Restriction: Implications for Aberrant Inflammation-Induced Trophoblast Dysfunction
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Alfian, I, Chakraborty, A, Yong, HEJ, Saini, S, Lau, RWK, Kalionis, B, Dimitriadis, E, Alfaidy, N, Ricardo, SD, Samuel, CS, Murthi, P, Alfian, I, Chakraborty, A, Yong, HEJ, Saini, S, Lau, RWK, Kalionis, B, Dimitriadis, E, Alfaidy, N, Ricardo, SD, Samuel, CS, and Murthi, P
- Abstract
Fetal growth restriction (FGR) is commonly associated with placental insufficiency and inflammation. Nonetheless, the role played by inflammasomes in the pathogenesis of FGR is poorly understood. We hypothesised that placental inflammasomes are differentially expressed and contribute to the aberrant trophoblast function. Inflammasome gene expression profiles were characterised by real-time PCR on human placental tissues collected from third trimester FGR and gestation-matched control pregnancies (n = 25/group). The functional significance of a candidate inflammasome was then investigated using lipopolysaccharide (LPS)-induced models of inflammation in human trophoblast organoids, BeWo cells in vitro, and a murine model of FGR in vivo. Placental mRNA expression of NLRP3, caspases 1, 3, and 8, and interleukin 6 increased (>2-fold), while that of the anti-inflammatory cytokine, IL-10, decreased (<2-fold) in FGR compared with control pregnancies. LPS treatment increased NLRP3 and caspase-1 expression (>2-fold) in trophoblast organoids and BeWo cell cultures in vitro, and in the spongiotrophoblast and labyrinth in the murine model of FGR. However, the LPS-induced rise in NLRP3 was attenuated by its siRNA-induced down-regulation in BeWo cell cultures, which correlated with reduced activity of the apoptotic markers, caspase-3 and 8, compared to the control siRNA-treated cells. Our findings support the role of the NLRP3 inflammasome in the inflammation-induced aberrant trophoblast function, which may contribute to FGR.
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- 2022
7. A Novel Approach to Enhance the Regenerative Potential of Circulating Endothelial Progenitor Cells in Patients with End-Stage Kidney Disease
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Badawi, A, Jefferson, OC, Huuskes, BM, Ricardo, SD, Kerr, PG, Samuel, CS, Murthi, P, Badawi, A, Jefferson, OC, Huuskes, BM, Ricardo, SD, Kerr, PG, Samuel, CS, and Murthi, P
- Abstract
Circulating bone marrow-derived endothelial progenitor cells (EPCs) facilitate vascular repair in several organs including the kidney but are progressively diminished in end-stage kidney disease (ESKD) patients, which correlates with cardiovascular outcomes and related mortality. We thus determined if enhancing the tissue-reparative effects of human bone marrow-derived mesenchymal stromal cells (BM-MSCs) with the vasculogenic effects of recombinant human relaxin (RLX) could promote EPC proliferation and function. CD34+ EPCs were isolated from the blood of healthy and ESKD patients, cultured until late EPCs had formed, then stimulated with BM-MSC-derived condition media (CM; 25%), RLX (1 or 10 ng/mL), or both treatments combined. Whilst RLX alone stimulated EPC proliferation, capillary tube formation and wound healing in vitro, these measures were more rapidly and markedly enhanced by the combined effects of BM-MSC-derived CM and RLX in EPCs derived from both healthy and ESKD patients. These findings have important clinical implications, having identified a novel combination therapy that can restore and enhance EPC number and function in ESKD patients.
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- 2022
8. COVID toe in an adolescent boy: a case report
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Wong, Joshua SC, primary, Wong, TS, additional, Chua, Gilbert T, additional, Wan, Christy, additional, Lau, SH, additional, Lau, Samuel CS, additional, Rosa Duque, Jaime S, additional, Wong, Ian CK, additional, To, Kelvin KW, additional, Tso, Winnie WY, additional, Wong, Christine S, additional, Ho, Marco HK, additional, Kwok, Janette, additional, Chow, CB, additional, Tam, Paul KH, additional, Chan, Godfrey CF, additional, Leung, WH, additional, Lau, YL, additional, Ip, Patrick, additional, and Kwan, Mike YW, additional
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- 2022
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9. Reducing bias in trials due to reactions to measurement: experts produced recommendations informed by evidence
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French, David P, primary, Miles, Lisa M, additional, Elbourne, Diana, additional, Farmer, Andrew, additional, Gulliford, Martin, additional, Locock, Louise, additional, Sutton, Stephen, additional, McCambridge, Jim, additional, Bower, Prof Peter, additional, Clemes, Dr Stacy, additional, Conner, Prof Mark, additional, Dundas, Ms Ruth, additional, Elbourne, Prof Diana, additional, Eldridge, Prof Sandra, additional, Farmer, Prof Andrew, additional, French, Prof David, additional, Gamble, Prof Carrol, additional, Gulliford, Prof Martin, additional, Kee, Prof Frank, additional, Leyland, Prof Alastair, additional, Locock, Prof Louise, additional, Lynch, Dr Rebecca, additional, MacLennan, Prof Graeme, additional, McCambridge, Prof Jim, additional, Miles, Dr Lisa, additional, Rowley, Dr Samuel CS, additional, Sharples, Prof Linda, additional, Sniehotta, Prof Falko F, additional, Snowdon, Dr Claire, additional, Sprangers, Prof Mirjam, additional, and Sutton, Prof Stephen, additional
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- 2021
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10. Placebo comparator group selection and use in surgical trials: the ASPIRE project including expert workshop
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Beard, David J, primary, Campbell, Marion K, additional, Blazeby, Jane M, additional, Carr, Andrew J, additional, Weijer, Charles, additional, Cuthbertson, Brian H, additional, Buchbinder, Rachelle, additional, Pinkney, Thomas, additional, Bishop, Felicity L, additional, Pugh, Jonathan, additional, Cousins, Sian, additional, Harris, Ian, additional, Lohmander, L Stefan, additional, Blencowe, Natalie, additional, Gillies, Katie, additional, Probst, Pascal, additional, Brennan, Carol, additional, Cook, Andrew, additional, Farrar-Hockley, Dair, additional, Savulescu, Julian, additional, Huxtable, Richard, additional, Rangan, Amar, additional, Tracey, Irene, additional, Brocklehurst, Peter, additional, Ferreira, Manuela L, additional, Nicholl, Jon, additional, Reeves, Barnaby C, additional, Hamdy, Freddie, additional, Rowley, Samuel CS, additional, Lee, Naomi, additional, and Cook, Jonathan A, additional
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- 2021
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11. Combining mesenchymal stem cells with serelaxin provides enhanced renoprotection against 1K/DOCA/salt-induced hypertension
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Li, Y, Shen, M, Ferens, D, Broughton, BRS, Murthi, P, Saini, S, Widdop, RE, Ricardo, SD, Pinar, AA, Samuel, CS, Li, Y, Shen, M, Ferens, D, Broughton, BRS, Murthi, P, Saini, S, Widdop, RE, Ricardo, SD, Pinar, AA, and Samuel, CS
- Abstract
BACKGROUND AND PURPOSE: Fibrosis is a hallmark of chronic kidney disease (CKD) that significantly contributes to renal dysfunction, and impairs the efficacy of stem cell-based therapies. This study determined whether combining bone marrow-derived mesenchymal stem cells (BM-MSCs) with the renoprotective effects of recombinant human relaxin (serelaxin) could therapeutically reduce renal fibrosis in mice with one kidney/deoxycorticosterone acetate/salt (1K/DOCA/salt)-induced hypertension, compared with the effects of the ACE inhibitor, perindopril. EXPERIMENTAL APPROACH: Adult male C57BL/6 mice were uni-nephrectomised and received deoxycorticosterone acetate and saline to drink (1K/DOCA/salt) for 21 days. Control mice were uni-nephrectomised but received water over the same time period. Sub-groups of 1K/DOCA/salt-injured mice (n = 5-8 per group) were treated with either serelaxin (0.5 mg·kg-1 ·day-1 ) or BM-MSCs (1 × 106 per mouse) alone; both treatments combined (with 0.5 × 106 or 1 × 106 BM-MSCs per mouse); or perindopril (2 mg·kg-1 ·day-1 ) from days 14-21. KEY RESULTS: 1K/DOCA/salt-injured mice developed elevated BP and hypertension-induced renal damage, inflammation and fibrosis. BM-MSCs alone reduced the injury-induced fibrosis and attenuated BP to a similar extent as perindopril. Serelaxin alone modestly reduced renal fibrosis and effectively reduced tubular injury. Strikingly, the combined effects of BM-MSCs (at both doses) with serelaxin significantly inhibited renal fibrosis and proximal tubular epithelial injury while restoring renal architecture, to a greater extent than either therapy alone, and over the effects of perindopril. CONCLUSION AND IMPLICATIONS: Combining BM-MSCs and serelaxin provided broader renoprotection over either therapy alone or perindopril and might represent a novel treatment for hypertensive CKD.
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- 2021
12. The efficacy and safety of pinocembrin in a sheep model of bleomycin-induced pulmonary fibrosis
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Freeman, CM, Derseh, HB, Goodger, JQD, Scheerlinck, J-PY, Samuel, CS, Woodrow, IE, Palombo, EA, Cumming, A, Snibson, K, Freeman, CM, Derseh, HB, Goodger, JQD, Scheerlinck, J-PY, Samuel, CS, Woodrow, IE, Palombo, EA, Cumming, A, and Snibson, K
- Abstract
The primary flavonoid, pinocembrin, is thought to have a variety of medical uses which relate to its reported anti-oxidant, anti-inflammatory, anti-microbial and anti-cancer properties. Some studies have reported that this flavonoid has anti-fibrotic activities. In this study, we investigated whether pinocembrin would impede fibrosis, dampen inflammation and improve lung function in a large animal model of pulmonary fibrosis. Fibrosis was induced in two localized lung segments in each of the 10 sheep participating in the study. This was achieved via two infusions of bleomycin delivered bronchoscopically at a two-week interval. Another lung segment in the same sheep was left untreated, and was used as a healthy control. The animals were kept for a little over 5 weeks after the final infusion of bleomycin. Pinocembrin, isolated from Eucalyptus leaves, was administered to one of the two bleomycin damaged lung segments at a dose of 7 mg. This dose was given once-weekly over 4-weeks, starting one week after the final bleomycin infusion. Lung compliance (as a measure of stiffness) was significantly improved after four weekly administrations of pinocembrin to bleomycin-damaged lung segments. There were significantly lower numbers of neutrophils and inflammatory cells in the bronchoalveolar lavage of bleomycin-infused lung segments that were treated with pinocembrin. Compared to bleomycin damaged lung segments without drug treatment, pinocembrin administration was associated with significantly lower numbers of immuno-positive CD8+ and CD4+ T cells in the lung parenchyma. Histopathology scoring data showed that pinocembrin treatment was associated with significant improvement in inflammation and overall pathology scores. Hydroxy proline analysis showed that the administration of pinocembrin did not reduce the increased collagen content that was induced by bleomycin in this model. Analyses of Masson's Trichrome stained sections showed that pinocembrin treatment significantly
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- 2021
13. Investigation of molecular mechanisms of experimental compounds in murine models of chronic allergic airways disease using synchrotron Fourier-transform infrared microspectroscopy
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Mazarakis, N, Vongsvivut, J, Bambery, KR, Ververis, K, Tobin, MJ, Royce, SG, Samuel, CS, Snibson, KJ, Licciardi, PV, Karagiannis, TC, Mazarakis, N, Vongsvivut, J, Bambery, KR, Ververis, K, Tobin, MJ, Royce, SG, Samuel, CS, Snibson, KJ, Licciardi, PV, and Karagiannis, TC
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The ovalbumin-induced (OVA) chronic allergic airways murine model is a well-established model for investigating pre-clinical therapies for chronic allergic airways diseases, such as asthma. Here, we examined the effects of several experimental compounds with potential anti-asthmatic effects including resveratrol (RV), relaxin (RLN), L-sulforaphane (LSF), valproic acid (VPA), and trichostatin A (TSA) using both a prevention and reversal model of chronic allergic airways disease. We undertook a novel analytical approach using focal plane array (FPA) and synchrotron Fourier-transform infrared (S-FTIR) microspectroscopic techniques to provide new insights into the mechanisms of action of these experimental compounds. Apart from the typical biological effects, S-FTIR microspectroscopy was able to detect changes in nucleic acids and protein acetylation. Further, we validated the reduction in collagen deposition induced by each experimental compound evaluated. Although this has previously been observed with conventional histological methods, the S-FTIR technique has the advantage of allowing identification of the type of collagen present. More generally, our findings highlight the potential utility of S-FTIR and FPA-FTIR imaging techniques in enabling a better mechanistic understanding of novel asthma therapeutics.
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- 2020
14. Inflammasomes-A Molecular Link for Altered Immunoregulation and Inflammation Mediated Vascular Dysfunction in Preeclampsia
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Murthi, P, Pinar, AA, Dimitriadis, E, Samuel, CS, Murthi, P, Pinar, AA, Dimitriadis, E, and Samuel, CS
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Preeclampsia (PE) is a pregnancy-specific multisystem disorder and is associated with maladaptation of the maternal cardiovascular system and abnormal placentation. One of the important characteristics in the pathophysiology of PE is a dysfunction of the placenta. Placental insufficiency is associated with poor trophoblast uterine invasion and impaired transformation of the uterine spiral arterioles to high capacity and low impedance vessels and/or abnormalities in the development of chorionic villi. Significant progress in identifying potential molecular targets in the pathophysiology of PE is underway. The human placenta is immunologically functional with the trophoblast able to generate specific and diverse innate immune-like responses through their expression of multimeric self-assembling protein complexes, termed inflammasomes. However, the type of response is highly dependent upon the stimuli, the receptor(s) expressed and activated, the downstream signaling pathways involved, and the timing of gestation. Recent findings highlight that inflammasomes can act as a molecular link for several components at the syncytiotrophoblast surface and also in maternal blood thereby directly influencing each other. Thus, the inflammasome molecular platform can promote adverse inflammatory effects when chronically activated. This review highlights current knowledge in placental inflammasome expression and activity in PE-affected pregnancies, and consequently, vascular dysfunction in PE that must be addressed as an interdependent interactive process.
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- 2020
15. Adenoid cystic carcinoma of the lower lip and buccal mucosa: A case report with review of literature
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James, Amritha, primary, Gunasekaran, Nandhini, additional, Shalini, SG, additional, Sherwin Samuel, CS, additional, Dolly, ASheryl, additional, and Shree Abiraami, NS, additional
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- 2021
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16. Considerations and methods for placebo controls in surgical trials (ASPIRE guidelines)
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Beard, David J, primary, Campbell, Marion K, additional, Blazeby, Jane M, additional, Carr, Andrew J, additional, Weijer, Charles, additional, Cuthbertson, Brian H, additional, Buchbinder, Rachelle, additional, Pinkney, Thomas, additional, Bishop, Felicity L, additional, Pugh, Jonathan, additional, Cousins, Sian, additional, Harris, Ian A, additional, Lohmander, L Stefan, additional, Blencowe, Natalie, additional, Gillies, Katie, additional, Probst, Pascal, additional, Brennan, Carol, additional, Cook, Andrew, additional, Farrar-Hockley, Dair, additional, Savulescu, Julian, additional, Huxtable, Richard, additional, Rangan, Amar, additional, Tracey, Irene, additional, Brocklehurst, Peter, additional, Ferreira, Manuela L, additional, Nicholl, Jon, additional, Reeves, Barnaby C, additional, Hamdy, Freddie, additional, Rowley, Samuel CS, additional, and Cook, Jonathan A, additional
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- 2020
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17. Therapeutic effects of Serelaxin in acute heart failure
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Du, X-J, Hewitson, TD, Nguyen, M-N, and Samuel, CS
- Abstract
Over the past few decades, research on the peptide hormone, relaxin, has significantly improved our understanding of its biological actions under physiological and diseased conditions. This has facilitated the conducting of clinical trials to explore the use of serelaxin (human recombinant relaxin). Acute heart failure (AHF) is a very difficult to treat clinical entity, with limited success so far in developing new drugs to combat it. A recent phase-III RELAX-AHF trial using serelaxin therapy given during hospitalization revealed acute (ameliorated dyspnea) and chronic (improved 180-day survival) effects. Although these findings support a substantial improvement by serelaxin therapy over currently available therapies for AHF, they also raise key questions and stimulate new hypotheses. To facilitate the development of serelaxin as a new drug for heart disease, joint efforts of clinicians, research scientists and pharmacological industries are necessary to study these questions and hypotheses. In this review, after providing a brief summary of clinical findings and the pathophysiology of AHF, we present a working hypothesis of the mechanisms responsible for the observed efficacy of serelaxin in AHF patients. The existing clinical and preclinical data supporting our hypotheses are summarized and discussed. The development of serelaxin as a drug provides an excellent example of the bilateral nature of translational research
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- 2019
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18. Endothelial Progenitor Cells and Vascular Health in Dialysis Patients
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Huuskes, BM, DeBuque, RJ, Polkinghorne, KR, Samuel, CS, Kerr, PG, Ricardo, SD, Huuskes, BM, DeBuque, RJ, Polkinghorne, KR, Samuel, CS, Kerr, PG, and Ricardo, SD
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- 2018
19. Anti-fibrotic actions of relaxin
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Samuel, CS, Royce, SG, Hewitson, TD, Denton, KM, Cooney, TE, Bennett, RG, Samuel, CS, Royce, SG, Hewitson, TD, Denton, KM, Cooney, TE, and Bennett, RG
- Abstract
UNLABELLED: Fibrosis refers to the hardening or scarring of tissues that usually results from aberrant wound healing in response to organ injury, and its manifestations in various organs have collectively been estimated to contribute to around 45-50% of deaths in the Western world. Despite this, there is currently no effective cure for the tissue structural and functional damage induced by fibrosis-related disorders. Relaxin meets several criteria of an effective anti-fibrotic based on its specific ability to inhibit pro-fibrotic cytokine and/or growth factor-mediated, but not normal/unstimulated, fibroblast proliferation, differentiation and matrix production. Furthermore, relaxin augments matrix degradation through its ability to up-regulate the release and activation of various matrix-degrading matrix metalloproteinases and/or being able to down-regulate tissue inhibitor of metalloproteinase activity. Relaxin can also indirectly suppress fibrosis through its other well-known (anti-inflammatory, antioxidant, anti-hypertrophic, anti-apoptotic, angiogenic, wound healing and vasodilator) properties. This review will outline the organ-specific and general anti-fibrotic significance of exogenously administered relaxin and its mechanisms of action that have been documented in various non-reproductive organs such as the cardiovascular system, kidney, lung, liver, skin and tendons. In addition, it will outline the influence of sex on relaxin's anti-fibrotic actions, highlighting its potential as an emerging anti-fibrotic therapeutic. LINKED ARTICLES: This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.
- Published
- 2017
20. Editorial: Novel Therapeutic Targets and Emerging Treatments for Fibrosis
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Samuel, CS, Hewitson, TD, Samuel, CS, and Hewitson, TD
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- 2017
21. Anti-fibrotic Potential of AT2 Receptor Agonists
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Wang, Y, Del Borgo, M, Lee, HW, Baraldi, D, Hirmiz, B, Gaspari, TA, Denton, KM, Aguilar, M-I, Samuel, CS, Widdop, RE, Wang, Y, Del Borgo, M, Lee, HW, Baraldi, D, Hirmiz, B, Gaspari, TA, Denton, KM, Aguilar, M-I, Samuel, CS, and Widdop, RE
- Abstract
There are a number of therapeutic targets to treat organ fibrosis that are under investigation in preclinical models. There is increasing evidence that stimulation of the angiotensin II type 2 receptor (AT2R) is a novel anti-fibrotic strategy and we have reviewed the published in vivo preclinical data relating to the effects of compound 21 (C21), which is the only nonpeptide AT2R agonist that is currently available for use in chronic preclinical studies. In particular, the differential influence of AT2R on extracellular matrix status in various preclinical fibrotic models is discussed. Collectively, these studies demonstrate that pharmacological AT2R stimulation using C21 decreases organ fibrosis, which has been most studied in the setting of cardiovascular and renal disease. In addition, AT2R-mediated anti-inflammatory effects may contribute to the beneficial AT2R-mediated anti-fibrotic effects seen in preclinical models.
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- 2017
22. A single-chain derivative of the relaxin hormone is a functionally selective agonist of the G protein-coupled receptor, RXFP1
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Hossain, MA, Kocan, M, Yao, ST, Royce, SG, Nair, VB, Siwek, C, Patil, NA, Harrison, IP, Rosengren, KJ, Selemidis, S, Summers, RJ, Wade, JD, Bathgate, RAD, Samuel, CS, Hossain, MA, Kocan, M, Yao, ST, Royce, SG, Nair, VB, Siwek, C, Patil, NA, Harrison, IP, Rosengren, KJ, Selemidis, S, Summers, RJ, Wade, JD, Bathgate, RAD, and Samuel, CS
- Abstract
Human gene-2 relaxin (H2 relaxin) is a pleiotropic hormone with powerful vasodilatory and anti-fibrotic properties which has led to its clinical evaluation and provisional FDA approval as a treatment for acute heart failure. The diverse effects of H2 relaxin are mediated via its cognate G protein coupled-receptor (GPCR), Relaxin Family Peptide Receptor (RXFP1), leading to stimulation of a combination of cell signalling pathways that includes cyclic adenosine monophosphate (cAMP) and extracellular-signal-regulated kinases (ERK)1/2. However, its complex two-chain (A and B), disulfide-rich insulin-like structure is a limitation to its facile preparation, availability and affordability. Furthermore, its strong activation of cAMP signaling is likely responsible for reported detrimental tumor-promoting actions that may preclude long-term use of this drug for treating human disease. Here we report the design and synthesis of a H2 relaxin B-chain-only analogue, B7-33, which was shown to bind to RXFP1 and preferentially activate the pERK pathway over cAMP in cells that endogenously expressed RXFP1. Thus, B7-33 represents the first functionally selective agonist of the complex GPCR, RXFP1. Importantly, this small peptide agonist prevented or reversed organ fibrosis and dysfunction in three pre-clinical rodent models of heart or lung disease with similar potency to H2 relaxin. The molecular mechanism behind the strong anti-fibrotic actions of B7-33 involved its activation of RXFP1-angiotensin II type 2 receptor heterodimers that induced selective downstream signaling of pERK1/2 and the collagen-degrading enzyme, matrix metalloproteinase (MMP)-2. Furthermore, in contrast to H2 relaxin, B7-33 did not promote prostate tumor growth in vivo. Our results represent the first known example of the minimisation of a two-chain cyclic insulin-like peptide to a single-chain linear peptide that retains potent beneficial agonistic effects.
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- 2016
23. Synthetic Covalently Linked Dimeric Form of H2 Relaxin Retains Native RXFP1 Activity and Has Improved In Vitro Serum Stability
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Nair, VB, Bathgate, RAD, Separovic, F, Samuel, CS, Hossain, MA, Wade, JD, Nair, VB, Bathgate, RAD, Separovic, F, Samuel, CS, Hossain, MA, and Wade, JD
- Abstract
Human (H2) relaxin is a two-chain peptide member of the insulin superfamily and possesses potent pleiotropic roles including regulation of connective tissue remodeling and systemic and renal vasodilation. These effects are mediated through interaction with its cognate G-protein-coupled receptor, RXFP1. H2 relaxin recently passed Phase III clinical trials for the treatment of congestive heart failure. However, its in vivo half-life is short due to its susceptibility to proteolytic degradation and renal clearance. To increase its residence time, a covalent dimer of H2 relaxin was designed and assembled through solid phase synthesis of the two chains, including a judiciously monoalkyne sited B-chain, followed by their combination through regioselective disulfide bond formation. Use of a bisazido PEG7 linker and "click" chemistry afforded a dimeric H2 relaxin with its active site structurally unhindered. The resulting peptide possessed a similar secondary structure to the native monomeric H2 relaxin and bound to and activated RXFP1 equally well. It had fewer propensities to activate RXFP2, the receptor for the related insulin-like peptide 3. In human serum, the dimer had a modestly increased half-life compared to the monomeric H2 relaxin suggesting that additional oligomerization may be a viable strategy for producing longer acting variants of H2 relaxin.
- Published
- 2015
24. M2 macrophage accumulation in the aortic wall during angiotensin II infusion in mice is associated with fibrosis, elastin loss, and elevated blood pressure
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Moore, JP, Vinh, A, Tuck, KL, Sakkal, S, Krishnan, SM, Chan, CT, Lieu, M, Samuel, CS, Diep, H, Kemp-Harper, BK, Tare, M, Ricardo, SD, Guzik, TJ, Sobey, CG, Drummond, GR, Moore, JP, Vinh, A, Tuck, KL, Sakkal, S, Krishnan, SM, Chan, CT, Lieu, M, Samuel, CS, Diep, H, Kemp-Harper, BK, Tare, M, Ricardo, SD, Guzik, TJ, Sobey, CG, and Drummond, GR
- Abstract
Macrophages accumulate in blood vessels during hypertension. However, their contribution to vessel remodeling is unknown. In the present study, we examined the polarization state of macrophages (M1/M2) in aortas of mice during hypertension and investigated whether antagonism of chemokine receptors involved in macrophage accumulation reduces vessel remodeling and blood pressure (BP). Mice treated with ANG II (0.7 mg·kg(-1)·day(-1), 14 days) had elevated systolic BP (158 ± 3 mmHg) compared with saline-treated animals (122 ± 3 mmHg). Flow cytometry revealed that ANG II infusion increased numbers of CD45(+)CD11b(+)Ly6C(hi) monocytes and CD45(+)CD11b(+)F4/80(+) macrophages by 10- and 2-fold, respectively. The majority of macrophages were positive for the M2 marker CD206 but negative for the M1 marker inducible nitric oxide synthase. Expression of other M2 genes (arginase-1, Fc receptor-like S scavenger receptor, and receptor-1) was elevated in aortas from ANG II-treated mice, whereas M1 genes [TNF and chemokine (C-X-C motif) ligand 2] were unaltered. A PCR array to identify chemokine receptor targets for intervention revealed chemokine (C-C motif) receptor 2 (CCR2) to be upregulated in aortas from ANG II-treated mice, while flow cytometry identified Ly6C(hi) monocytes as the main CCR2-expressing cell type. Intervention with a CCR2 antagonist (INCB3344; 30 mg·kg(-1)·day(-1)), 7 days after the commencement of ANG II infusion, reduced aortic macrophage numbers. INCB334 also reduced aortic collagen deposition, elastin loss, and BP in ANG II-treated mice. Thus, ANG II-dependent hypertension in mice is associated with Ly6C(hi) monocyte and M2 macrophage accumulation in the aorta. Inhibition of macrophage accumulation with a CCR2 antagonist prevents ANG II-induced vessel fibrosis and elevated BP, highlighting this as a promising approach for the future treatment of vessel remodeling/stiffening in hypertension.
- Published
- 2015
25. Low-dose maternal alcohol consumption: effects in the hearts of offspring in early life and adulthood.
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Nguyen, VB, Probyn, ME, Campbell, F, Yin, KV, Samuel, CS, Zimanyi, MA, Bertram, JF, Black, MJ, Moritz, KM, Nguyen, VB, Probyn, ME, Campbell, F, Yin, KV, Samuel, CS, Zimanyi, MA, Bertram, JF, Black, MJ, and Moritz, KM
- Abstract
High alcohol consumption during pregnancy leads to deleterious effects on fetal cardiac structure and it also affects cardiomyocyte growth and maturation. This study aimed to determine whether low levels of maternal alcohol consumption are also detrimental to cardiomyocyte and cardiac growth in the early life of offspring and whether cardiac structure and function in adulthood is affected. Pregnant Sprague-Dawley rat dams were fed a control or 6% (volume/volume) liquid-based ethanol supplemented (isocaloric) diet throughout gestation. At embryonic day 20, the expression of genes involved in cardiac development was analyzed using Real-time PCR. At postnatal day 30, cardiomyocyte number, size, and nuclearity in the left ventricle (LV) were determined stereologically. In 8-month-old offspring, LV fibrosis and cardiac function (by echocardiography) were examined. Maternal ethanol consumption did not alter gene expression of the cardiac growth factors in the fetus or cardiomyocyte number in weanling offspring. However, at 8 months, there were significant increases in LV anterior and posterior wall thickness during diastole in ethanol-exposed offspring (P = 0.037 and P = 0.024, respectively), indicative of left ventricular hypertrophy; this was accompanied by a significant increase in fibrosis. Additionally, maximal aortic flow velocity was significantly decreased in ethanol-exposed offspring (P = 0.035). In conclusion, although there were no detectable early-life differences in cardiac and cardiomyocyte growth in animals exposed to a chronic low dose of ethanol during gestation, there were clearly deleterious outcomes by adulthood. This suggests that even relatively low doses of alcohol consumed during pregnancy can be detrimental to long-term cardiac health in the offspring.
- Published
- 2014
26. Does a Nephron Deficit Exacerbate the Renal and Cardiovascular Effects of Obesity?
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Long, D, Gurusinghe, S, Brown, RD, Cai, X, Samuel, CS, Ricardo, SD, Thomas, MC, Kett, MM, Long, D, Gurusinghe, S, Brown, RD, Cai, X, Samuel, CS, Ricardo, SD, Thomas, MC, and Kett, MM
- Abstract
It has been hypothesized that a reduced nephron endowment exacerbates the hypertensive and renal effects of obesity. We therefore examined the impact of diet-induced obesity on renal structure and function, and arterial pressure in a genetic model of reduced nephron endowment, the GDNF Heterozygous (HET) mouse. 6 wk-old male GDNF WT and HET mice were placed on control or high fat (HFF) diet for 20 weeks. 24 hr arterial pressure, heart rate and activity (radiotelemetry), creatinine clearance and albumin excretion were measured, and kidneys collected (histopathology, collagen content). Bodyweights of HFF WT (50.6 ± 1.2 g) and HET (48.8 ± 1.4 g) mice were ∼14 g greater than control mice (37.3 ± 1.3 g, 36.4 ± 1.1 g respectively; Pdiet<0.001). Obesity led to significantly greater 24 hr MAP (Pdiet<0.001), heart rate (Pdiet<0.01) and lower locomotor activity (Pdiet<0.01) in HET and WT mice. Whilst there was no significant impact of genotype on 24 hr MAP response to obesity, night-time MAP of obese HET mice was significantly greater than obese WT mice (122.3 ± 1.6 vs 116.9 ± 1.3 mmHg; P<0.05). 24 hr creatinine clearance was 50%, and albumin excretion 180% greater in obese WT and HET mice compared to controls (Pdiet<0.05) but this response did not differ between genotypes. Obesity induced glomerulomegaly, glomerulosclerosis, tubulointerstitial expansion and increased collagen accumulation (total, collagen I, V and IV; Pdiet<0.001). Obese GDNF HET mice had exacerbated total renal collagen (P<0.01), and greater levels of the collagen I subtype compared to kidneys of obese WT mice. In summary, obese nephron-deficient GDNF HET mice were able to maintain the high creatinine clearances of obese WT mice but at the expense of higher MAP and greater renal fibrosis. Whilst modest, our findings support the hypothesis that a reduced nephron endowment increases the susceptibility to obesity-induced kidney disease and hypertension.
- Published
- 2013
27. Identification of Key Residues Essential for the Structural Fold and Receptor Selectivity within the A-chain of Human Gene-2 (H2) Relaxin
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Chan, LJ, Rosengren, KJ, Layfield, SL, Bathgate, RAD, Separovic, F, Samuel, CS, Hossain, MA, Wade, JD, Chan, LJ, Rosengren, KJ, Layfield, SL, Bathgate, RAD, Separovic, F, Samuel, CS, Hossain, MA, and Wade, JD
- Abstract
Human gene-2 (H2) relaxin is currently in Phase III clinical trials for the treatment of acute heart failure. It is a 53-amino acid insulin-like peptide comprising two chains and three disulfide bonds. It interacts with two of the relaxin family peptide (RXFP) receptors. Although its cognate receptor is RXFP1, it is also able to cross-react with RXFP2, the native receptor for a related peptide, insulin-like peptide 3. In order to understand the basis of this cross-reactivity, it is important to elucidate both binding and activation mechanisms of this peptide. The primary binding mechanism of this hormone has been extensively studied and well defined. H2 relaxin binds to the leucine-rich repeats of RXFP1 and RXFP2 using B-chain-specific residues. However, little is known about the secondary interaction that involves the A-chain of H2 relaxin and transmembrane exoloops of the receptors. We demonstrate here through extensive mutation of the A-chain that the secondary interaction between H2 relaxin and RXFP1 is not driven by any single amino acid, although residues Tyr-3, Leu-20, and Phe-23 appear to contribute. Interestingly, these same three residues are important drivers of the affinity and activity of H2 relaxin for RXFP2 with additional minor contributions from Lys-9, His-12, Lys-17, Arg-18, and Arg-22. Our results provide new insights into the mechanism of secondary activation interaction of RXFP1 and RXFP2 by H2 relaxin, leading to a potent and RXFP1-selective analog, H2:A(4-24)(F23A), which was tested in vitro and in vivo and found to significantly inhibit collagen deposition similar to native H2 relaxin.
- Published
- 2012
28. Human relaxin-2: historical perspectives and role in cancer biology
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Nair, VB, Samuel, CS, Separovic, F, Hossain, MA, Wade, JD, Nair, VB, Samuel, CS, Separovic, F, Hossain, MA, and Wade, JD
- Abstract
One of the most recognised and studied family of peptide hormones is the insulin superfamily. Within this family is the relaxin subfamily which comprises seven members: relaxin-1, -2 and -3 and insulin-like peptides 3, 4, 5 and 6. Besides exhibiting sequence similarities, each member exists as an active A-B heterodimer linked by three disulfide bonds. This mini-review is divided into three broad themes: an overview of all insulin superfamily members (including structural similarities); roles of each superfamily member and finally, a focus on the pleiotropic peptide hormone, human relaxin-2. In addition to promoting vasodilatory effects leading to evaluation in Phase III clinical trials for the treatment of acute heart failure, relaxin has recently been shown to be highly expressed by cancer cells, aiding in their proliferation, invasiveness and metastasis. These contrary effects of relaxin are discussed together with current efforts in the development of relaxin antagonists that may possess future therapeutic potential for the treatment of certain cancers.
- Published
- 2012
29. The Minimal Active Structure of Human Relaxin-2
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Hossain, MA, Rosengren, KJ, Samuel, CS, Shabanpoor, F, Chan, LJ, Bathgate, RAD, Wade, JD, Hossain, MA, Rosengren, KJ, Samuel, CS, Shabanpoor, F, Chan, LJ, Bathgate, RAD, and Wade, JD
- Abstract
H2 relaxin is a peptide hormone associated with a number of therapeutically relevant physiological effects, including regulation of collagen metabolism and multiple vascular control pathways. It is currently in phase III clinical trials for the treatment of acute heart failure due to its ability to induce vasodilation and influence renal function. It comprises 53 amino acids and is characterized by two separate polypeptide chains (A-B) that are cross-linked by three disulfide bonds. This size and complex structure represents a considerable challenge for the chemical synthesis of H2 relaxin, a major limiting factor for the exploration of modifications and derivatizations of this peptide, to optimize effect and drug-like characteristics. To address this issue, we describe the solid phase peptide synthesis and structural and functional evaluation of 24 analogues of H2 relaxin with truncations at the termini of its peptide chains. We show that it is possible to significantly truncate both the N and C termini of the B-chain while still retaining potent biological activity. This suggests that these regions are not critical for interactions with the H2 relaxin receptor, RXFP1. In contrast, truncations do reduce the activity of H2 relaxin for the related receptor RXFP2 by improving RXFP1 selectivity. In addition to new mechanistic insights into the function of H2 relaxin, this study identifies a critical active core with 38 amino acids. This minimized core shows similar antifibrotic activity as native H2 relaxin when tested in human BJ3 cells and thus represents an attractive receptor-selective lead for the development of novel relaxin therapeutics.
- Published
- 2011
30. Effects of relaxin, pregnancy and parturition on collagen metabolism in the rat pubic symphysis
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Samuel, CS, primary, Coghlan, JP, additional, and Bateman, JF, additional
- Published
- 1998
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31. Relaxin and the progression of kidney disease.
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Samuel CS and Hewitson TD
- Published
- 2009
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32. Thermal imaging through hot emissive windows.
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Prasad CS, Everitt HO, and Naik GV
- Abstract
It is not currently possible for an infrared camera to see through a hot window. The window's own blinding thermal emission prevents objects on the other side from being imaged. Here, we demonstrate a path to overcoming this challenge by coating a hot window with an asymmetrically emitting infrared metasurface whose specially engineered imaginary index of refraction produces an asymmetric spatial distribution of absorption losses in its constituent nanoscale resonators. Operating at 873 K, this metasurface-coated window suppresses thermal emission towards the camera while being sufficiently transparent for thermal imaging, doubling the thermal imaging contrast when compared to a control window at the same temperature., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)
- Published
- 2024
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33. The renoprotective efficacy and safety of genetically-engineered human bone marrow-derived mesenchymal stromal cells expressing anti-fibrotic cargo.
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Li Y, Hunter A, Wakeel MM, Sun G, Lau RWK, Broughton BRS, Pino IEO, Deng Z, Zhang T, Murthi P, Del Borgo MP, Widdop RE, Polo JM, Ricardo SD, and Samuel CS
- Subjects
- Humans, Animals, Fibrosis, Male, Renal Insufficiency, Chronic therapy, Renal Insufficiency, Chronic metabolism, Renal Insufficiency, Chronic pathology, Cell Differentiation, Bone Marrow Cells metabolism, Bone Marrow Cells cytology, Green Fluorescent Proteins metabolism, Green Fluorescent Proteins genetics, Genetic Engineering, Kidney pathology, Kidney metabolism, Reperfusion Injury metabolism, Mice, Mesenchymal Stem Cells metabolism, Mesenchymal Stem Cell Transplantation methods, Relaxin genetics, Relaxin pharmacology, Relaxin metabolism
- Abstract
Background: Kidney fibrosis is a hallmark of chronic kidney disease (CKD) and compromises the viability of transplanted human bone marrow-derived mesenchymal stromal cells (BM-MSCs). Hence, BM-MSCs were genetically-engineered to express the anti-fibrotic and renoprotective hormone, human relaxin-2 (RLX) and green fluorescent protein (BM-MSCs-eRLX + GFP), which enabled BM-MSCs-eRLX + GFP delivery via a single intravenous injection., Methods: BM-MSCs were lentiviral-transduced with human relaxin-2 cDNA and GFP, under a eukaryotic translation elongation factor-1α promoter (BM-MSCs-eRLX + GFP) or GFP alone (BM-MSCs-eGFP). The ability of BM-MSCs-eRLX + GFP to differentiate, proliferate, migrate, produce RLX and cytokines was evaluated in vitro, whilst BM-MSC-eRLX + GFP vs BM-MSCs-eGFP homing to the injured kidney and renoprotective effects were evaluated in preclinical models of ischemia reperfusion injury (IRI) and high salt (HS)-induced hypertensive CKD in vivo. The long-term safety of BM-MSCs-RLX + GFP was also determined 9-months after treatment cessation in vivo., Results: When cultured for 3- or 7-days in vitro, 1 × 10
6 BM-MSCs-eRLX + GFP produced therapeutic RLX levels, and secreted an enhanced but finely-tuned cytokine profile without compromising their proliferation or differentiation capacity compared to naïve BM-MSCs. BM-MSCs-eRLX + GFP were identified in the kidney 2-weeks post-administration and retained the therapeutic effects of RLX in vivo. 1-2 × 106 BM-MSCs-eRLX + GFP attenuated the IRI- or therapeutically abrogated the HS-induced tubular epithelial damage and interstitial fibrosis, and significantly reduced the HS-induced hypertension, glomerulosclerosis and proteinuria. This was to an equivalent extent as RLX and BM-MSCs administered separately but to a broader extent than BM-MSCs-eGFP or the angiotensin-converting enzyme inhibitor, perindopril. Additionally, these renoprotective effects of BM-MSCs-eRLX + GFP were maintained in the presence of perindopril co-treatment, highlighting their suitability as adjunct therapies to ACE inhibition. Importantly, no major long-term adverse effects of BM-MSCs-eRLX + GFP were observed., Conclusions: BM-MSCs-eRLX + GFP produced greater renoprotective and therapeutic efficacy over that of BM-MSCs-eGFP or ACE inhibition, and may represent a novel and safe treatment option for acute kidney injury and hypertensive CKD., (© 2024. The Author(s).)- Published
- 2024
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34. Loss of Bicra/Gltscr1 leads to a defect in fetal liver macrophages responsible for erythrocyte maturation in mice.
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Sood S, Alpsoy A, Jiao G, Dhiman A, King CS, Conjelko G, Hallett J, Utturkar S, Hutchcroft J, and Dykhuizen E
- Abstract
GLTSCR1, a protein encoded by the Bicra gene, is a defining subunit of the SWI/SNF (also called mammalian BAF) chromatin remodeling subcomplex called GBAF/ncBAF. To determine the role of GLTSCR1 during mouse development, we generated a Bicra germline knockout mouse using CRISPR/Cas9. Mice with homozygous loss of Bicra were born at Mendelian ratios but were small, pale and died within 24 hours after birth. Histology indicated blood-related defects including defective erythroblastic islands and irregularly sized red blood cells. Gene expression profiling of fetal livers pinpointed a defect in liver resident macrophages involved in the last stage of erythrocyte maturation, resulting in accumulation of nucleated erythrocytes in Bicra-/- pups. Together, these results demonstrate that Bicra is critical for fetal liver macrophage function during development.
- Published
- 2024
- Full Text
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35. Sex- and time-dependent role of insulin regulated aminopeptidase in lipopolysaccharide-induced inflammation.
- Author
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Vear A, Chakraborty A, Fahimi F, Ferens D, Widdop R, Samuel CS, Gaspari T, van Endert PM, and Chai SY
- Subjects
- Animals, Female, Male, Mice, Mice, Inbred C57BL, Sex Factors, Time Factors, Lipopolysaccharides immunology, Mice, Knockout, Cystinyl Aminopeptidase metabolism, Cystinyl Aminopeptidase genetics, Inflammation immunology, Macrophages immunology, Macrophages metabolism, Dendritic Cells immunology, Dendritic Cells metabolism
- Abstract
The enzyme, insulin regulated aminopeptidase (IRAP), is expressed in multiple immune cells such as macrophages, dendritic cells and T cells, where it plays a role in regulating the innate and adaptive immune response. There is a genetic association between IRAP and survival outcomes in patients with septic shock where a variant of its gene was found to be associated with increased 28-day mortality. This study investigated the role for IRAP in a lipopolysaccharide (LPS)-induced inflammatory response which is thought to model facets of the systemic inflammation observed in the early stages of human gram-negative sepsis. The frequencies and activation of splenic immune cell populations were investigated in the IRAP knockout (KO) mice compared to the wildtype controls over a period of 4-, 24-, or 48-hours following LPS stimulation. Dendritic cells isolated from the spleen of female IRAP KO mice, displayed significant increases in the activation markers CD40, CD86 and MHCII at 24 hours after LPS induction. A modest heightened pro-inflammatory response to LPS was observed with increased expression of activation marker CD40 in M1 macrophages from male IRAP knockout mice. Observations in vitro in bone marrow-derived macrophages (BMDM) revealed a heightened pro-inflammatory response to LPS with significant increases in the expression of CD40 in IRAP deficient cells compared with BMDM from WT mice. The heightened LPS-induced response was associated with increased pro-inflammatory cytokine secretion in these BMDM cells. A genotype difference was also detected in the BMDM from female mice displaying suppression of the LPS-induced increases in the activation markers CD40, CD86, CD80 and MHCII in IRAP deficient cells. Thus, this study suggests that IRAP plays specific time- and sex-dependent roles in the LPS-induced inflammatory response in dendritic cells and macrophages., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Vear, Chakraborty, Fahimi, Ferens, Widdop, Samuel, Gaspari, van Endert and Chai.)
- Published
- 2024
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36. Induced pluripotent stem cell-derived mesenchymal stem cells reverse bleomycin-induced pulmonary fibrosis and related lung stiffness.
- Author
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Chakraborty A, Wang C, Hodgson-Garms M, Broughton BRS, Frith JE, Kelly K, and Samuel CS
- Subjects
- Animals, Male, Mice, Cell Differentiation drug effects, Cytokines metabolism, Disease Models, Animal, Transforming Growth Factor beta1 metabolism, Bleomycin, Induced Pluripotent Stem Cells, Mice, Inbred C57BL, Mesenchymal Stem Cells metabolism, Pulmonary Fibrosis chemically induced, Pulmonary Fibrosis pathology, Pulmonary Fibrosis therapy, Lung pathology, Lung drug effects, Lung metabolism, Mesenchymal Stem Cell Transplantation methods
- Abstract
Idiopathic pulmonary fibrosis (IPF) is characterised by lung scarring and stiffening, for which there is no effective cure. Based on the immunomodulatory and anti-fibrotic effects of induced pluripotent stem cell (iPSC) and mesenchymoangioblast-derived mesenchymal stem cells (iPSCs-MSCs), this study evaluated the therapeutic effects of iPSCs-MSCs in a bleomycin (BLM)-induced model of pulmonary fibrosis. Adult male C57BL/6 mice received a double administration of BLM (0.15 mg/day) 7-days apart and were then maintained for a further 28-days (until day-35), whilst control mice were administered saline 7-days apart and maintained for the same time-period. Sub-groups of BLM-injured mice were intravenously-injected with 1×10
6 iPSC-MSCs on day-21 alone or on day-21 and day-28 and left until day-35 post-injury. Measures of lung inflammation, fibrosis and compliance were then evaluated. BLM-injured mice presented with lung inflammation characterised by increased immune cell infiltration and increased pro-inflammatory cytokine expression, epithelial damage, lung transforming growth factor (TGF)-β1 activity, myofibroblast differentiation, interstitial collagen fibre deposition and topology (fibrosis), in conjunction with reduced matrix metalloproteinase (MMP)-to-tissue inhibitor of metalloproteinase (TIMP) ratios and dynamic lung compliance. All these measures were ameliorated by a single or once-weekly intravenous-administration of iPSC-MSCs, with the latter reducing dendritic cell infiltration and lung epithelial damage, whilst promoting anti-inflammatory interleukin (IL)-10 levels to a greater extent. Proteomic profiling of the conditioned media of cultured iPSC-MSCs that were stimulated with TNF-α and IFN-γ, revealed that these stem cells secreted protein levels of immunosuppressive factors that contributed to the anti-fibrotic and therapeutic potential of iPSCs-MSCs as a novel treatment option for IPF., Competing Interests: Declaration of Competing Interest All Authors have nothing to disclose., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)- Published
- 2024
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- View/download PDF
37. Functional crosstalk between angiotensin receptors (types 1 and 2) and relaxin family peptide receptor 1 (RXFP1): Implications for the therapeutic targeting of fibrosis.
- Author
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Samuel CS, Li Y, Wang Y, and Widdop RE
- Subjects
- Humans, Animals, Receptors, Peptide metabolism, Receptor, Angiotensin, Type 2 metabolism, Receptor, Angiotensin, Type 2 agonists, Fibrosis drug therapy, Receptors, G-Protein-Coupled metabolism, Receptors, G-Protein-Coupled antagonists & inhibitors, Receptor, Angiotensin, Type 1 metabolism
- Abstract
Class A, rhodopsin-like, G-protein-coupled receptors (GPCRs) are by far the largest class of GPCRs and are integral membrane proteins used by various cells to convert extracellular signals into intracellular responses. Initially, class A GPCRs were believed to function as monomers, but a growing body of evidence has emerged to suggest that these receptors can function as homodimers and heterodimers and can undergo functional crosstalk to influence the actions of agonists or antagonists acting at each receptor. This review will focus on the angiotensin type 1 (AT
1 ) and type 2 (AT2 ) receptors, as well as the relaxin family peptide receptor 1 (RXFP1), each of which have their unique characteristics but have been demonstrated to undergo some level of interaction when appropriately co-expressed, which influences the function of each receptor. In particular, this receptor functional crosstalk will be discussed in the context of fibrosis, the tissue scarring that results from a failed wound-healing response to injury, and which is a hallmark of chronic disease and related organ dysfunction. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc., (© 2022 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)- Published
- 2024
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38. Exploring the anti-inflammatory and anti-fibrotic activity of NFκB decoy oligodeoxynucleotide-loaded spermine-functionalized acetalated nanoparticles.
- Author
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De Rubis G, Chakraborty A, Paudel KR, Wang C, Kannaujiya V, Wich PR, Hansbro PM, Samuel CS, Oliver B, and Dua K
- Subjects
- Humans, Transforming Growth Factor beta metabolism, Fibroblasts drug effects, Fibroblasts metabolism, Fibrosis drug therapy, Oligodeoxyribonucleotides pharmacology, Oligodeoxyribonucleotides chemistry, Nanoparticles chemistry, Anti-Inflammatory Agents pharmacology, Anti-Inflammatory Agents chemistry, NF-kappa B metabolism, Spermine pharmacology, Spermine chemistry, Lipopolysaccharides pharmacology
- Abstract
Chronic inflammation, oxidative stress, and airway remodelling represent the principal pathophysiological features of chronic respiratory disorders. Inflammation stimuli like lipopolysaccharide (LPS) activate macrophages and dendritic cells, with concomitant M1 polarization and release of pro-inflammatory cytokines. Chronic inflammation and oxidative stress lead to airway remodelling causing irreversible functional and structural alterations of the lungs. Airway remodelling is multifactorial, however, the hormone transforming growth factor-β (TGF-β) is one of the main contributors to fibrotic changes. The signalling pathways mediating inflammation and remodelling rely both on the transcription factor nuclear factor-κB (NFκB), underlying the potential of NFκB inhibition as a therapeutic strategy for chronic respiratory disorders. In this study, we encapsulated an NFκB-inhibiting decoy oligodeoxynucleotide (ODN) in spermine-functionalized acetalated dextran (SpAcDex) nanoparticles and tested the in vitro anti-inflammatory and anti-remodelling activity of this formulation. We show that NF-κB ODN nanoparticles counteract inflammation by reversing LPS-induced expression of the activation marker CD40 in myeloid cells and counteracts remodelling features by reversing the TGF-β-induced expression of collagen I and α-smooth muscle actin in human dermal fibroblast. In summary, our study highlights the great potential of inhibiting NFκB via decoy ODN as a therapeutic strategy tackling multiple pathophysiological features underlying chronic respiratory conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
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39. The involvement of the Wnt/β-catenin signaling cascade in fibrosis progression and its therapeutic targeting by relaxin.
- Author
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Somanader DVN, Zhao P, Widdop RE, and Samuel CS
- Subjects
- Humans, beta Catenin metabolism, Acute Disease, Wnt Signaling Pathway, Transforming Growth Factor beta1, Fibrosis, Relaxin therapeutic use
- Abstract
Organ scarring, referred to as fibrosis, results from a failed wound-healing response to chronic tissue injury and is characterised by the aberrant accumulation of various extracellular matrix (ECM) components. Once established, fibrosis is recognised as a hallmark of stiffened and dysfunctional tissues, hence, various fibrosis-related diseases collectively contribute to high morbidity and mortality in developed countries. Despite this, these diseases are ineffectively treated by currently-available medications. The pro-fibrotic cytokine, transforming growth factor (TGF)-β
1 , has emerged as the master regulator of fibrosis progression, owing to its ability to promote various factors and processes that facilitate rapid ECM synthesis and deposition, whilst negating ECM degradation. TGF-β1 signal transduction is tightly controlled by canonical (Smad-dependent) and non-canonical (MAP kinase- and Rho-associated protein kinase-dependent) intracellular protein activity, whereas its pro-fibrotic actions can also be facilitated by the Wnt/β-catenin pathway. This review outlines the pathological sequence of events and contributing roles of TGF-β1 in the progression of fibrosis, and how the Wnt/β-catenin pathway contributes to tissue repair in acute disease settings, but to fibrosis and related tissue dysfunction in synergy with TGF-β1 in chronic diseases. It also outlines the anti-fibrotic and related signal transduction mechanisms of the hormone, relaxin, that are mediated via its negative modulation of TGF-β1 and Wnt/β-catenin signaling, but through the promotion of Wnt/β-catenin activity in acute disease settings. Collectively, this highlights that the crosstalk between TGF-β1 signal transduction and the Wnt/β-catenin cascade may provide a therapeutic target that can be exploited to broadly treat and reverse established fibrosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)- Published
- 2024
- Full Text
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40. SMC-5/6 complex subunit NSE-1 plays a crucial role in meiosis and DNA repair in Caenorhabditis elegans.
- Author
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Odiba AS, Ezechukwu CS, Liao G, Hong Y, Fang W, Jin C, Gartner A, and Wang B
- Subjects
- Animals, Male, Humans, Cell Cycle Proteins metabolism, DNA Repair, Meiosis, Genomic Instability, Caenorhabditis elegans genetics, Caenorhabditis elegans metabolism, Caenorhabditis elegans Proteins genetics
- Abstract
The SMC5/6 complex is evolutionarily conserved across all eukaryotes and plays a pivotal role in preserving genomic stability. Mutations in genes encoding SMC5/6 complex subunits have been associated with human lung disease, immunodeficiency, and chromosome breakage syndrome. Despite its critical importance, much about the SMC5/6 complex remains to be elucidated. Various evidences have suggested possible role of a subunit of the SMC5/6 complex, NSE1, in chromosome segregation and DNA repair. Current knowledge regarding the role of NSE1 is primarily derived from single-cell-based analyses in yeasts, Arabidopsis thaliana, and human cell lines. However, our understanding of its function is still limited and requires further investigation. This study delves into the role of nse-1 in Caenorhabditis elegans, revealing its involvement in meiotic recombination and DNA repair. nse-1 mutants display reduced fertility, increased male incidence, and increased sensitivity to genotoxic chemicals due to defects in meiotic chromosome segregation and DNA repair. These defects manifest as increased accumulation of RAD-51 foci, increased chromosome fragmentation, and susceptibility to MMS, cisplatin, and HU. Furthermore, nse-1 mutation exacerbates germ cell death by upregulating ced-13 and egl-1 genes involved in the CEP-1/p53-mediated apoptotic pathway. NSE-1 is essential for the proper localization of NSE-4 and MAGE-1 on the chromosomes. Collectively, these findings firmly establish nse-1 as a crucial factor in maintaining genomic stability., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
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- 2024
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41. Anxiety and its risk factors among non-Japanese residents living in Japan undergoing COVID-19 situation: A cross-sectional survey.
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Luu MN, Imoto A, Matsuo Y, Huy NT, Qarawi A, Alhady STM, Truong LV, Yoshino R, Duc NTM, Tabei K, Lu Y, Singh MK, Truong MP, Dumre SP, Rocha ICN, Hung IC, Fudo A, Sato M, Kansakar S, Tsukamoto A, Komatsu A, Cai G, Moji K, Khongyot T, Mogan S, Soukdavone S, Hartuti ED, Thidatheb K, Honda S, Woo H, Lama N, Huynh VTN, Khoa HLA, Abbas KS, Monib FA, Omran HAM, Rezq CS, Qatora MS, Jia Ng S, Morena GJV, Miranda AV, Ngo Huynh MT, Ota J, Minjung K, An J, Vorlasane L, Gunasegaran K, Zulkefli F, Lima Girón BJ, Bhattachan PG, Dumre RB, Pandey K, Yamashita S, Seposo AKC, Zabala J, Riva-Moscoso A, Ordóñez JNP, Uitrakul S, Principe-Meneses FS, and Dila KAS
- Subjects
- Humans, Cross-Sectional Studies, Japan epidemiology, Anxiety epidemiology, Risk Factors, Depression, Pandemics, COVID-19 epidemiology
- Abstract
Introduction: In the context of collective efforts taken in Japan to control the spread of COVID-19, the state of emergency and social distancing have caused a negative impact on the mental health of all residents, including foreign communities in Japan. This study aimed to evaluate the level of anxiety and its associated factors among non-Japanese residents residing in Japan during the COVID-19 pandemic., Methods: A web-based survey in 13 languages was conducted among non-Japanese residents living in Japan during the COVID-19 situation. The State-Trait Anxiety Inventory assessed the level of anxiety-State (STAI-S) scores prorated from its six-item version. The multivariable logistic regression using the Akaike Information Criterion (AIC) method was performed to identify the associated factors of anxiety among participants., Results: From January to March 2021, we collected 392 responses. A total of 357 valid responses were analyzed. 54.6% of participants suffered from clinically significant anxiety (CSA). In multivariable logistic model analysis, the CSA status or the high level of anxiety was associated with three factors, including having troubles/difficulties in learning or working, decreased sleep duration, and decreased overall physical health (p<0.05)., Conclusion: Our study suggests several possible risk factors of anxiety among non-Japanese residents living in Japan undergoing the COVID-19 pandemic, including the troubles or difficulties in learning or working, the decrease in sleep duration, and the decrease in overall physical health., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Luu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2024
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42. IL-4 and IL-13 induce equivalent expression of traditional M2 markers and modulation of reactive oxygen species in human macrophages.
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Scott TE, Lewis CV, Zhu M, Wang C, Samuel CS, Drummond GR, and Kemp-Harper BK
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- Humans, Cytokines metabolism, Interleukin-4 pharmacology, Interleukin-4 metabolism, Macrophages metabolism, Reactive Oxygen Species metabolism, Superoxides metabolism, Cardiovascular Diseases metabolism, Interleukin-13 pharmacology, Interleukin-13 metabolism
- Abstract
In cardiovascular disease, pathological and protective roles are reported for the Th2 cytokines IL-4 and IL-13, respectively. We hypothesised that differential effects on macrophage function are responsible. Type I and II receptor subunit (IL-2Rγ, IL-4Rα and IL-13Rα1) and M2 marker (MRC-1, CCL18, CCL22) expression was assessed via RT-qPCR in IL-4- and IL-13-treated human primary macrophages. Downstream signalling was evaluated via STAT1, STAT3 and STAT6 inhibitors, and IL-4- and IL-13-induced reactive oxygen species (ROS) generation assessed. IL-4 and IL-13 exhibited equivalent potency and efficacy for M2 marker induction, which was attenuated by STAT3 inhibition. Both cytokines enhanced PDBu-stimulated superoxide generation however this effect was 17% greater with IL-4 treatment. Type I IL-4 receptor expression was increased on M1-like macrophages but did not lead to a differing ability of these cytokines to modulate M1-like macrophage superoxide production. Overall, this study did not identify major differences in the ability of IL-4 and IL-13 to modulate macrophage function, suggesting that the opposing roles of these cytokines in cardiovascular disease are likely to be via actions on other cell types. Future studies should directly compare IL-4 and IL-13 in vivo to more thoroughly investigate the therapeutic validity of selective targeting of these cytokines., (© 2023. The Author(s).)
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- 2023
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43. Anti-inflammatory and anti-fibrotic effects of berberine-loaded liquid crystalline nanoparticles.
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Chakraborty A, Paudel KR, Wang C, De Rubis G, Chellappan DK, Hansbro PM, Samuel CS, and Dua K
- Abstract
Competing Interests: The authors declare that they have no conflict of interest.
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- 2023
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44. Caenorhabditis elegans NSE3 homolog (MAGE-1) is involved in genome stability and acts in inter-sister recombination during meiosis.
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Odiba AS, Liao G, Ezechukwu CS, Zhang L, Hong Y, Fang W, Jin C, Gartner A, and Wang B
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- Animals, Humans, Cell Cycle Proteins genetics, Chromosomal Proteins, Non-Histone genetics, Chromosomal Proteins, Non-Histone metabolism, Meiosis genetics, Saccharomyces cerevisiae genetics, Caenorhabditis elegans genetics, Caenorhabditis elegans metabolism, Caenorhabditis elegans Proteins genetics, Caenorhabditis elegans Proteins metabolism, Genomic Instability, Nuclear Proteins genetics, Nuclear Proteins metabolism
- Abstract
Melanoma antigen (MAGE) genes encode for a family of proteins that share a common MAGE homology domain. These genes are conserved in eukaryotes and have been linked to a variety of cellular and developmental processes including ubiquitination and oncogenesis in cancer. Current knowledge on the MAGE family of proteins mainly comes from the analysis of yeast and human cell lines, and their functions have not been reported at an organismal level in animals. Caenorhabditis elegans only encodes 1 known MAGE gene member, mage-1 (NSE3 in yeast), forming part of the SMC-5/6 complex. Here, we characterize the role of mage-1/nse-3 in mitosis and meiosis in C. elegans. mage-1/nse-3 has a role in inter-sister recombination repair during meiotic recombination and for preserving chromosomal integrity upon treatment with a variety of DNA-damaging agents. MAGE-1 directly interacts with NSE-1 and NSE-4. In contrast to smc-5, smc-6, and nse-4 mutants which cause the loss of NSE-1 nuclear localization and strong cytoplasmic accumulation, mage-1/nse-3 mutants have a reduced level of NSE-1::GFP, remnant NSE-1::GFP being partially nuclear but largely cytoplasmic. Our data suggest that MAGE-1 is essential for NSE-1 stability and the proper functioning of the SMC-5/6 complex., Competing Interests: Conflicts of interest The authors declare that there is no conflict of interest related to this study., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Genetics Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
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- 2023
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45. Novel AT 2 R agonist, β-Pro 7 Ang III, is cardio- and vaso-protective in diabetic spontaneously hypertensive rats.
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Li M, Nguyen L, Ferens D, Spizzo I, Wang Y, Denton KM, Del Borgo M, Kulkarni K, Aguilar MI, Qin CH, Samuel CS, Gaspari TA, and Widdop RE
- Subjects
- Animals, Rats, Benzimidazoles pharmacology, Benzimidazoles therapeutic use, Rats, Inbred SHR, Receptor, Angiotensin, Type 1 metabolism, Superoxides, Cardiotonic Agents, Diabetes Mellitus, Hypertension complications, Hypertension drug therapy
- Abstract
Stimulation of the angiotensin II type 2 receptor (AT
2 R) evokes protective effects in various cardiovascular diseases. Thus, this study aimed to investigate the effects of AT2 R stimulation, with or without AT1 R blockade, in a model of hypertension with concomitant type 1 diabetes mellitus (T1DM). Spontaneously hypertensive rats (SHRs) were given either citrate or a single dose of streptozotocin (STZ; 55 mg/kg, i.p.) to induce diabetes. After 4 weeks of diabetes, animals were administered either a vehicle (saline), AT2 R agonist, β-Pro7 Ang III (0.1 mg/kg/day via osmotic mini-pump), AT1 R blocker, candesartan (2 mg/kg/day via drinking water), or a combination of both for a further 8 weeks. β-Pro7 Ang III treatment had no effect on blood pressure, but attenuated the significant increase in cardiac interstitial collagen and protein expression of fibrotic and inflammatory markers, and superoxide levels that was evident in diabetic SHRs. These effects were not observed with candesartan, despite its blood pressure lowering effects. Although β-Pro7 Ang III had no effect on aortic fibrosis, it significantly attenuated MCP-1 protein expression and superoxide levels when compared to both the non-diabetic and diabetic SHRs, to a similar extent as candesartan. In both the heart and vasculature, the effects of β-Pro7 Ang III in combination with candesartan were similar to those of β-Pro7 Ang III alone, and superior to candesartan alone. It was concluded that in hypertension with concomitant diabetes, AT2 R stimulation with a novel ligand alone, or in combination with AT1 R blockade, improved the cardiac and vascular structural changes that were strongly associated with inflammation and oxidative stress, independent of blood pressure regulation., Competing Interests: Declaration of Competing Interest Please declare any financial or personal interests that might be potentially viewed to influence the work presented. Interests could include consultancies, honoraria, patent ownership or other. If there are none state ‘there are none’., (Copyright © 2023. Published by Elsevier Masson SAS.)- Published
- 2023
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46. Development of Novel High-Affinity Antagonists for the Relaxin Family Peptide Receptor 1.
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Hossain MA, Praveen P, Noorzi NA, Wu H, Harrison IP, Handley T, Selemidis S, Samuel CS, and Bathgate RAD
- Abstract
H2 relaxin is a peptide hormone that exerts its biological actions through the G protein-coupled receptor, RXFP1. The numerous important biological functions of H2 relaxin, including potent renal, vasodilatory, cardioprotective, and anti-fibrotic actions, have resulted in considerable interest in its use as a therapeutic for various cardiovascular diseases and other fibrotic indications. Interestingly though, H2 relaxin and RXFP1 have been shown to be overexpressed in prostate cancer, allowing for the downregulation or blocking of relaxin/RXFP1 to decrease prostate tumor growth. These findings suggest the application of an RXFP1 antagonist for the treatment of prostate cancer. However, these therapeutically relevant actions are still poorly understood and have been hindered by the lack of a high-affinity antagonist. In this study, we chemically synthesized three novel H2 relaxin analogues that have complex insulin-like structures with two chains (A and B) and three disulfide bridges. We report here the structure-activity relationship studies on H2 relaxin that resulted in the development of a novel high-affinity RXFP1 antagonist, H2 B-R13HR (∼40 nM), that has only one extra methylene group in the side chain of arginine 13 in the B-chain (Arg
B13 ) of H2 relaxin. Most notably, the synthetic peptide was shown to be active in a mouse model of prostate tumor growth in vivo where it inhibited relaxin-mediated tumor growth. Our compound H2 B-R13HR will be an important research tool to understand relaxin actions through RXFP1 and may be a potential lead compound for the treatment of prostate cancer., Competing Interests: The authors declare no competing financial interest., (© 2023 American Chemical Society.)- Published
- 2023
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47. The protective effects of a novel AT 2 receptor agonist, β-Pro 7 Ang III in ischemia-reperfusion kidney injury.
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Zhang T, Li Y, Wise AF, Kulkarni K, Aguilar MI, Samuel CS, Del Borgo M, Widdop RE, and Ricardo SD
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- Mice, Animals, Lipopolysaccharides pharmacology, Mice, Inbred C57BL, Kidney, Collagen pharmacology, Reperfusion, Acute Kidney Injury drug therapy, Acute Kidney Injury prevention & control, Reperfusion Injury genetics
- Abstract
Background and Purpose: This study investigated the reno-protective effects of a highly selective AT
2 R agonist peptide, β-Pro7 Ang III in a mouse model of acute kidney injury (AKI)., Methods: C57BL/6 J mice underwent either sham surgery or unilateral kidney ischemia-reperfusion injury (IRI) for 40 min. IRI mice were treated with either β-Pro7 Ang III or perindopril and at 7 days post-surgery the kidneys analysed for histopathology and the development of fibrosis and matrix metalloproteinase (MMP)-2 and -9 activity. The association of the therapeutic effects of β-Pro7 Ang III with macrophage number and phenotype was determined in vivo and in vitro., Key Results: Decreased kidney tubular injury, interstitial matrix expansion and reduced interstitial immune cell infiltration in IRI mice receiving β-Pro7 Ang III treatment was observed at day 7, compared to IRI mice without treatment. This correlated to reduced collagen accumulation and MMP-2 activity in IRI mice following β-Pro7 Ang III treatment. FACS analysis showed a reduced number and proportion of CD45+ CD11b+ F4/80+ macrophages in IRI kidneys in response to β-Pro7 Ang III, correlating with a significant increase in M2 macrophage markers and decreased M1 markers at day 3 and 7 post-IR injury, respectively. In vitro analysis of cultured THP-1 cells showed that β-Pro7 Ang III attenuated lipopolysaccharide (LPS)-induced tumour necrosis factor-α (TNF-α) and interleukin (IL)- 6 production but increased IL-10 secretion, compared to LPS alone., Conclusion: Administration of β-Pro7 Ang III via mini-pump improved kidney structure and reduced interstitial collagen accumulation, in parallel with an alteration of macrophage phenotype and anti-inflammatory cytokine release, therefore mitigating the downstream progression of ischemic AKI., Competing Interests: Conflict of interest statement The authors declare that there are no conflicts of interests., (Copyright © 2023. Published by Elsevier Masson SAS.)- Published
- 2023
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48. Does environment quality affect the health care spending? Nexus among CO 2 emissions, non-renewable energy production, financial development, and health care spending.
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Ramos-Meza CS, Flores-Arocutipa JP, Jinchuña-Huallpa J, Corzo-Palomo EE, Gamero-Huarcaya VK, Gutiérrez-Acuña Y, and Valencia-Martinez JC
- Subjects
- Economic Development, Environmental Pollution, Gross Domestic Product, Health Expenditures, Carbon Dioxide analysis
- Abstract
This study investigates the dynamic associations among carbon dioxide (CO
2 ) emissions, non-renewable energy production from petroleum derivatives, financial development, and healthcare expenditures to improve environmental quality. This research has employed the balanced annual panel of thirty (30) Organizations for Economic Co-operation and Development (OECD) countries' data set and applied panel vector autoregression (VAR) method depending on the generalized method of moments (GMM). Furthermore, the empirical findings reveal that health spending and CO2 emissions have a favorable bidirectional link, but there is no indication that health spending promotes power generation. The results demonstrate that increased energy consumption and productions affect pollution, and higher CO2 emissions increase healthcare costs. Whereas, energy consumption, financial development, and healthcare expenditures have a positive toward environmental quality., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2023
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49. A Lipidated Single-B-Chain Derivative of Relaxin Exhibits Improved In Vitro Serum Stability without Altering Activity.
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Praveen P, Wang C, Handley TNG, Wu H, Samuel CS, Bathgate RAD, and Hossain MA
- Subjects
- Animals, Humans, Receptors, G-Protein-Coupled chemistry, Structure-Activity Relationship, Fibrosis, Relaxin pharmacology
- Abstract
Human relaxin-2 (H2 relaxin) is therapeutically very important due to its strong anti-fibrotic, vasodilatory, and cardioprotective effects. Therefore, relaxin's receptor, relaxin family peptide receptor 1 (RXFP1), is a potential target for the treatment of fibrosis and related disorders, including heart failure. H2 relaxin has a complex two-chain structure (A and B) and three disulfide bridges. Our laboratory has recently developed B7-33 peptide, a single-chain agonist based on the B-chain of H2 relaxin. However, the peptide B7-33 has a short circulation time in vitro in serum (t
1/2 = ~6 min). In this study, we report structure-activity relationship studies on B7-33 utilizing different fatty-acid conjugations at different positions. We have shown that by fatty-acid conjugation with an appropriate spacer length, the in vitro half-life of B7-33 can be increased from 6 min to 60 min. In the future, the lead lipidated molecule will be studied in animal models to measure its PK/PD properties, which will lead to their pre-clinical applications.- Published
- 2023
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50. The single-chain relaxin mimetic, B7-33, maintains the cardioprotective effects of relaxin and more rapidly reduces left ventricular fibrosis compared to perindopril in an experimental model of cardiomyopathy.
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Alam F, Gaspari TA, Kemp-Harper BK, Low E, Aw A, Ferens D, Spizzo I, Jefferis AM, Praveen P, Widdop RE, Bathgate RAD, Hossain MA, and Samuel CS
- Subjects
- Mice, Animals, Male, Perindopril pharmacology, Perindopril therapeutic use, Models, Theoretical, Inflammation drug therapy, Hypertrophy drug therapy, Relaxin pharmacology, Microvascular Rarefaction drug therapy, Cardiomyopathies chemically induced, Cardiomyopathies drug therapy, Cardiomyopathies prevention & control
- Abstract
The hormone, relaxin (RLX), exerts various organ-protective effects independently of etiology. However, its complex two-chain and three disulphide bonded structure is a limitation to its preparation and affordability. Hence, a single chain-derivative of RLX, B7-33, was developed and shown to retain the anti-fibrotic effects of RLX in vitro and in vivo. Here, we determined whether B7-33 could retain the other cardioprotective effects of RLX, and also compared its therapeutic efficacy to the ACE inhibitor, perindopril. Adult male 129sv mice were subjected to isoprenaline (ISO; 25 mg/kg/day, s.c)-induced cardiomyopathy, then s.c-treated with either RLX (0.5 mg/kg/day), B7-33 (0.25 mg/kg/day; equivalent dose corrected for MW) or perindopril (1 mg/kg/day) from days 7-14 post-injury. Control mice received saline instead of ISO. Changes in animal body weight (BW) and systolic blood pressure (SBP) were measured weekly, whilst cardiomyocyte hypertrophy and measures of vascular dysfunction and rarefaction, left ventricular (LV) inflammation and fibrosis were assessed at day 14 post-injury. ISO-injured mice had significantly increased LV inflammation, cardiomyocyte hypertrophy, fibrosis, vascular rarefaction and aortic contractility in the absence of any changes in BW or SBP at day 14 post-injury. Both B7-33 and RLX equivalently reduced LV fibrosis and normalised the ISO-induced LV inflammation and cardiomyocyte hypertrophy, whilst restoring blood vessel density and aortic contractility. Comparatively, perindopril lowered SBP and the ISO-induced LV inflammation and vascular rarefaction, but not fibrosis or hypertrophy. As B7-33 retained the cardioprotective effects of RLX and provided rapid-occurring anti-fibrotic effects compared to perindopril, it could be considered as a cost-effective cardioprotective therapy., Competing Interests: Conflict of interest statement The authors declare no conflict of interest., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)
- Published
- 2023
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