Search

Cardiac hypertrophy is one of the key processes in the development of heart failure. Notably, small GTPases and GTPase‑activating proteins (GAPs) serve essential roles in cardiac hypertrophy. RhoGAP interacting with CIP4 homologs protein 1 (RICH1) is a RhoGAP that can regulate Cdc42/Rac1 and F‑actin dynamics. RICH1 is involved in cell proliferation and adhesion; however, to the best of our knowledge, its role in cardiac hypertrophy remains unknown. In the present study, the role of RICH1 in cardiomyocyte hypertrophy was assessed. Cell viability was analyzed using the Cell Counting Kit‑8 assay and cells surface area (CSA) was determined by cell fluorescence staining. Reverse transcription‑quantitative PCR and western blotting were used to assess the mRNA expression levels of hypertrophic marker genes, such as Nppa, Nppb and Myh7, and the protein expression levels of RICH1, respectively. RICH1 was shown to be downregulated in isoproterenol (ISO)‑ or angiotensin II (Ang II)‑treated H9c2 cells. Notably, overexpression of RICH1 attenuated the upregulation of hypertrophy‑related markers, such as Nppa, Nppb and Myh7, and the enlargement of CSA induced by ISO and Ang II. By contrast, the knockdown of RICH1 exacerbated these effects. These findings suggested that RICH1 may be a novel suppressor of ISO‑ or Ang II‑induced cardiomyocyte hypertrophy. The results of the present study will be beneficial to further studies assessing the role of RICH1 and its downstream molecules in inhibiting cardiac hypertrophy.

Maladaptive cardiac hypertrophy contributes to the development of heart failure (HF). The oxidoreductase Selenoprotein T (SELENOT) emerged as a key regulator during rat cardiogenesis and acute cardiac protection. However, its action in chronic settings of cardiac dysfunction is not understood. Here, we investigated the role of SELENOT in the pathophysiology of HF: (i) by designing a small peptide (PSELT), recapitulating SELENOT activity via the redox site, and assessed its beneficial action in a preclinical model of HF [aged spontaneously hypertensive heart failure (SHHF) rats] and against isoproterenol (ISO)-induced hypertrophy in rat ventricular H9c2 and adult human AC16 cardiomyocytes; (ii) by evaluating the SELENOT intra-cardiomyocyte production and secretion under hypertrophied stimulation. Results showed that PSELT attenuated systemic inflammation, lipopolysaccharide (LPS)-induced macrophage M1 polarization, myocardial injury, and the severe ultrastructural alterations, while counteracting key mediators of cardiac fibrosis, aging, and DNA damage and restoring desmin downregulation and SELENOT upregulation in the failing hearts. In the hemodynamic assessment, PSELT improved the contractile impairment at baseline and following ischemia/reperfusion injury, and reduced infarct size in normal and failing hearts. At cellular level, PSELT counteracted ISO-mediated hypertrophy and ultrastructural alterations through its redox motif, while mitigating ISO-triggered SELENOT intracellular production and secretion, a phenomenon that presumably reflects the extent of cell damage. Altogether, these results indicate that SELENOT could represent a novel sensor of hypertrophied cardiomyocytes and a potential PSELT-based new therapeutic approach in myocardial hypertrophy and HF., (© 2024. The Author(s).)

Adverse cardiac remodeling contributes to heart failure development and progression, partly due to inappropriate sympathetic nervous system activation. Although β-adrenergic receptor (β-AR) blockade is a common heart failure therapy, not all patients respond, prompting exploration of alternative treatments. Minocycline, an FDA-approved antibiotic, has pleiotropic properties beyond antimicrobial action. Recent evidence suggests it may alter gene expression via changes in miRNA expression. Thus, we hypothesized that minocycline could prevent adverse cardiac remodeling induced by the β-AR agonist isoproterenol, involving miRNA-mRNA transcriptome alterations. Male C57BL/6J mice received isoproterenol (30 mg/kg/day sc) or vehicle via osmotic minipump for 21 days, along with daily minocycline (50 mg/kg ip) or sterile saline. Isoproterenol induced cardiac hypertrophy without altering cardiac function, which minocycline prevented. Total mRNA sequencing revealed isoproterenol altering gene networks associated with inflammation and metabolism, with fibrosis activation predicted by integrated miRNA-mRNA sequencing, involving miR-21, miR-30a, miR-34a, miR-92a, and miR-150, among others. Conversely, the cardiac miRNA-mRNA transcriptome predicted fibrosis inhibition in minocycline-treated mice, involving antifibrotic shifts in Atf3 and Itgb6 gene expression associated with miR-194 upregulation. Picrosirius red staining confirmed isoproterenol-induced cardiac fibrosis, prevented by minocycline. These results demonstrate minocycline's therapeutic potential in attenuating adverse cardiac remodeling through miRNA-mRNA-dependent mechanisms, especially in reducing cardiac fibrosis. NEW & NOTEWORTHY We demonstrate that minocycline treatment prevents cardiac hypertrophy and fibrotic remodeling induced by chronic β-adrenergic stimulation by inducing antifibrotic shifts in the cardiac miRNA-mRNA transcriptome.

Cardiotoxicity (CT) is a severe condition that negatively impacts heart function. β-sitosterol (BS) is a group of phytosterols and known for various pharmacological benefits, such as managing diabetes, cardiac protection, and neuroprotection. This study aims to develop niosomes (NS) containing BS, utilizing cholesterol as the lipid and Tween 80 as the stabilizer. The research focuses on designing and evaluating both conventional BS-NS and hyaluronic acid (HA) modified NS (BS-HA-NS) to enhance the specificity and efficacy of BS within cardiac tissue. The resulting niosomal formulation was spherical, with a size of about 158.51 ± 0.57 nm, an entrapment efficiency of 93.56 ± 1.48 %, and a drug loading of 8.07 ± 1.62 %. To evaluate cytotoxicity on H9c2 heart cells, the MTT assay was used. The cellular uptake of BS-NS and BS-HA-NS was confirmed by confocal microscopy on H9c2 cardiac cells. Administering BS-NS and BS-HA-NS intravenously at a dose of 10 mg/kg showed the ability to significantly decrease the levels of cardiac troponin-I (cTn-I), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and lipid peroxidation (MDA). Tissue histopathology indicated a substantial potential for repairing cardiac tissue after treatment with BS-NS and BS-HA-NS and strong cardioprotection against ISO induced myocardial tissue damages. Thus, enhancing BS's therapeutic effectiveness through niosome surface modification holds promise for mitigating cardiac damage resulting from CT., 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.)

Background: A better understanding of adipose tissue (AT) dysfunction, which includes morphological and functional changes such as adipocyte hypertrophy as well as impaired adipogenesis, lipid storage/mobilization, endocrine and inflammatory responses, is needed in the context of obesity. One dimension of AT dysfunction, secretory adiposopathy, often assessed as a low plasma adiponectin (A)/leptin (L) ratio, is commonly observed in obesity. The aim of this study was to examine markers of AT development and metabolism in 67 women of varying age and adiposity (age: 40-62 years; body mass index, BMI: 17-41 kg/m 2 ) according to levels of adiponectinemia, leptinemia or the plasma A/L ratio., Methods: Body composition, regional AT distribution and circulating adipokines were determined. Lipolysis was measured from glycerol release in subcutaneous abdominal (SCABD) and omental (OME) adipocytes under basal, isoproterenol-, forskolin (FSK)- and dibutyryl-cyclic AMP (DcAMP)-stimulated conditions. Adipogenesis (C/EBP-α/β/δ, PPAR-γ2 and SREBP-1c) and lipid metabolism (β2-ARs, HSL, FABP4, LPL and GLUT4) gene expression (RT-qPCR) was assessed in both fat depots. Participants in the upper versus lower tertile of adiponectin, leptin or the A/L ratio were compared., Results: Basal lipolysis was similar between groups. Women with a low plasma A/L ratio were characterized by higher adiposity and larger SCABD and OME adipocytes (p<0.01) compared to those with a high ratio. In OME adipocytes, women in the low adiponectinemia tertile showed higher isoproterenol-stimulated lipolysis (0.01

The study sought to assess the detrimental effects of isoproterenol (ISO) on major organs and investigate the potential reversibility of these adverse reactions in mice. Male mice were divided into normal control, 0.2 mg/kg.d and 3.0 mg/kg.d ISO groups, and were subcutaneously administered of the respective doses for 14 consecutive days. Subsequently, a recovery period experiment was conducted, replicating the aforementioned procedure, followed by an additional 2-week recovery period for the mice. Following 14 consecutive days of administration, mice treated with ISO exhibited notable cardiac damage manifested by abnormal ECG patterns, dysregulated energy metabolism, elevated cardiac hypertrophy, and increased heart pathological score. Additionally, the administration of ISO resulted in liver and kidney damage, as evidenced by increased pathological score, serum albumin level, and urea level. Lung damage was also observed, indicated by an increase in lung pathological score. Furthermore, the administration of ISO at a dosage of 3.0 mg/kg.d resulted in a decrease in liver mass index, serum iron content, and an increase in lung mass index. After a 2-week recovery period, mice treated with ISO showed abnormalities in ECG patterns and dysregulated myocardial energy metabolism, accompanied by a decrease in serum iron content. Histopathological examinations revealed continued pathological changes in the heart and lung, as well as significant hemosiderin deposition in the spleen. Furthermore, the group treated with ISO at a dosage of 3.0 mg/kg.d showed an increase in serum AST and TP levels. In summary, the study demonstrates that both 0.2 mg/kg.d and 3.0 mg/kg.d doses of ISO can induce damage to the heart, liver, lung, kidney, and spleen, with the higher dose causing more severe injuries. After a 2-week withdrawal period, the liver, kidney, and thymus injuries caused by 0.2 mg/kg ISO shows signs of recovery, while damage to the heart, lung, and spleen persists. The thymus injury mostly recovers, with minimal kidney pathology, but significant damage to the heart, liver, and lung remains even after the withdrawal period for the 3.0 mg/kg ISO dose., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jian-ping Gao reports financial support was provided by the National Natural Science Foundation of China (Grant No. 82074055)., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Reductions in Na+-K+-ATPase (NKA) activity and expression are often observed in the progress of various reason-induced heart failure (HF). However, NKA α1 mutation or knockdown cannot cause spontaneous heart disease. Whether the abnormal NKA α1 directly contributes to HF pathogenesis remains unknown. Here, we challenge NKA α1+/- mice with isoproterenol to evaluate the role of NKA α1 haploinsufficiency in isoproterenol (ISO)-induced cardiac dysfunction. Genetic knockdown of NKA α1 accelerated ISO-induced cardiac cell hypertrophy, heart fibrosis, and dysfunction. Further studies revealed decreased Krebs cycle, fatty acid oxidation, and mitochondrial OXPHOS in the hearts of NKA α1+/- mice challenged with ISO. In ISO-treated conditions, inhibition of NKA elevated cytosolic Na+, further reduced mitochondrial Ca2+ via mNCE, and then finally down-regulated cardiac cell energy metabolism. In addition, a supplement of DRm217 alleviated ISO-induced heart dysfunction, mitigated cardiac remodeling, and improved cytosolic Na+ and Ca2+ elevation and mitochondrial Ca2+ depression in the NKA α1+/- mouse model. The findings suggest that targeting NKA and mitochondria Ca2+ could be a promising strategy in the treatment of heart disease., (© 2024 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Background: Myocardial necrosis is one of the most common cardiac and pathological diseases. Unfortunately, using the available medical treatment is not sufficient to rescue the myocardium. So that, we aimed in our model to study the possible cardioprotective effect of roflumilast (ROF) in an experimental model of induced myocardial injury using a toxic dose of isoprenaline (ISO) and detecting the role of vascular endothelial growth factor/endothelial nitric oxide synthase (VEGF/eNOS) and cyclic guanosine monophosphate/cyclic adenosine monophosphate/ sirtuin1 (cGMP/cAMP/SIRT1) signaling cascade., Materials and Methods: Animals were divided into five groups; control, ISO given group (150 mg/kg) i.p. on the 4th and 5th day, 3 ROF co-administered groups in different doses (0.25, 0.5, 1 mg/kg/day) for 5 days., Results: Our data revealed that ISO could induce cardiac toxicity as manifested by significant increases in troponin I, creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), and cleaved caspase-3 with toxic histopathological changes. Meanwhile, there were significant decreases in reduced glutathione (GSH), total antioxidant capacity (TAC), VEGF, eNOS, cGMP, cAMP and SIRT1. However, co-administration of ROF showed significant improvement and normalization of ISO induced cardiac damage., Conclusion: We concluded that ROF successfully reduced ISO induced myocardial injury and this could be attributed to modulation of PDE4, VEGF/eNOS and cGMP/cAMP/SIRT1 signaling pathways with antioxidant, anti-inflammatory, and anti-apoptotic properties.

In essence, the β 2 adrenergic receptor (β 2 AR) plays an antiproliferative role by increasing the intracellular cyclic 3',5'-adenosine monophosphate (cAMP) concentration through G αs coupling, but interestingly, β 2 AR antagonists are able to effectively inhibit fibroblast-like synoviocytes (FLSs) proliferation, thus ameliorating experimental RA, indicating that the β 2 AR signalling pathway is impaired in RA FLSs via unknown mechanisms. The local epinephrine (Epi) level was found to be much higher in inflammatory joints than in normal joints, and high-level stimulation with Epi or isoproterenol (ISO) directly promoted FLSs proliferation and migration due to impaired β 2 AR signalling and cAMP production. By applying inhibitor of receptor internalization, and small interfering RNA (siRNA) of G αs and G αi , and by using fluorescence resonance energy transfer and coimmunoprecipitation assays, a switch in G αs -G αi coupling to β 2 AR was observed in inflammatory FLSs as well as in FLSs with chronic ISO stimulation. This G αi coupling was then revealed to be initiated by G protein coupled receptor kinase 2 (GRK2) but not β-arrestin2 or protein kinase A-mediated phosphorylation of β 2 AR. Inhibiting the activity of GRK2 with the novel GRK2 inhibitor paeoniflorin-6'-O-benzene sulfonate (CP-25), a derivative of paeoniflorin, or the accepted GRK2 inhibitor paroxetine effectively reversed the switch in G αs -G αi coupling to β 2 AR during inflammation and restored the intracellular cAMP level in ISO-stimulated FLSs. As expected, CP-25 significantly inhibited the hyperplasia of FLSs in a collagen-induced arthritis (CIA) model (CIA FLSs) and normal FLSs stimulated with ISO and finally ameliorated CIA in rats. Together, our findings revealed the pathological changes in β 2 AR signalling in CIA FLSs, determined the underlying mechanisms and identified the pharmacological target of the GRK2 inhibitor CP-25 in treating CIA. Video Abstract., (© 2023. The Author(s).)

Canagliflozin (CZ) is commonly prescribed for management of type-2 diabetes mellitus (T2DM); it also can reduce the risk of myocardial infarction. We used 80 albino Wistar rats to investigate the cardioprotective potential of CZ against oxidative stress caused by administration of isoprenaline (ISO). We found that ISO stimulates production of reactive oxygen species and that CZ administration caused up-regulation of antioxidants and down-regulation of oxidants due to nuclear factor erythroid-2 related factor-2, as well as by enhancement of the heme oxygenase-1 mediated cascade. CZ monotherapy may play a cardioprotective role in diabetic patients. CZ possesses strong antioxidant potential that ameliorates cardiac damage induced by ISO administration.

The experimental myocardial infarction (MI) model originating from isoproterenol (ISO) is frequently preferred in research due to its similarity to MI-induced damage in humans. Beneficial effects of L-arginine (L-Arg), a semi-essential amino acid, in cardiovascular diseases have been shown in many studies. This study was carried out to determine whether L-Arg pre-intervention has protective effects on heart tissue in the experimental MI model. The 28 rats used in the study were randomly divided into 4 equal groups: control, L-Arg, ISO, and L-Arg+ISO. Upon completion of all applications, cardiac markers in serum and biochemical, histopathological, and immunohistochemical examinations in cardiac tissues were performed. Cardiac markers, histopathological changes, oxidative stress, inflammation, and apoptosis were increased in the experimental MI model. In addition, administration of ISO deregulated OTULIN levels and mitochondrial dynamics in heart tissue. However, L-Arg pre-intervention showed a significant protective effect against changes in ISO-induced MI. L-Arg supplementation with cardioprotective effect may reduce the risks of possible pathophysiological processes in MI., (© 2023. The Author(s), under exclusive licence to Cell Stress Society International.)

Background: Sustained, chronic activation of β-adrenergic receptor (β-AR) signaling leads to cardiac arrhythmias, with exchange proteins directly activated by cAMP (Epac1 and Epac2) as key mediators. This study aimed to evaluate whether CD44, a transmembrane receptor mediating various cellular responses, participates in Epac-dependent arrhythmias., Methods: The heart tissue from CD44 knockout (CD44 -/- ) mice, cultured HL-1 myocytes and the tissue of human ventricle were used for western blot, co-immunoprecipitaiton and confocal studies. Line-scanning confocal imaging was used for the study of cellular Ca 2+ sparks on myocytes. Optical mapping and intra-cardiac pacing were applied for arrhythmia studies on mice's hearts., Results: In mice, isoproterenol, a β-AR agonist, upregulated CD44 and Epac1 and increased the association between CD44 and Epac1. Isoproterenol upregulated the expression of phospho-CaMKII (p-CaMKII), phospho-ryanodine receptor (p-RyR), and phospho-phospholamban (p-PLN) in mice and cultured myocytes; these effects were attenuated in CD44 -/- mice compared with wild-type controls. In vitro, isoproterenol, 8-CPT-cAMP (an Epac agonist), and osteopontin (a ligand of CD44) significantly upregulated the expression of p-CaMKII, p-RyR, and p-PLN; this effect was attenuated by CD44 small interfering RNA (siRNA). In myocytes, resting Ca 2+ sparks were induced by isoproterenol and overexpressed CD44, which were prevented by inhibiting CD44. Ex vivo optical mapping and in vivo intra-cardiac pacing studies showed isoproterenol-induced triggered events and arrhythmias in ventricles were prevented in CD44 -/- mice. The inducibility of ventricular arrhythmias (VAs) was attenuated in CD44 -/- HF mice compared with wild-type HF controls. In patients, CD44 were upregulated, and the association between CD44 and Epac1 were increased in ventricles with reduced contractility., Conclusion: CD44 regulates β-AR- and Epac1-mediated Ca 2+ -handling abnormalities and VAs. Inhibition of CD44 is effective in reducing VAs in HF, which is potentially a novel therapeutic target for preventing the arrhythmias and sudden cardiac death in patients with diseased hearts., (© 2023. The Author(s).)

Chlorprenaline hydrochloride (CLOR) is a typical representative of β-adrenergic agonists that may be used illegally as a livestock feed additive and may have adverse impacts on the environment. In the present study, zebrafish embryos were exposed to CLOR to investigate its developmental toxicity and neurotoxicity. The results demonstrated that CLOR exposure led to adverse effects on developing zebrafish, such as morphological changes, a high heart rate, and increased body length, resulting in developmental toxicity. Moreover, the up-regulation of activities of superoxide dismutase (SOD) and catalase (CAT) and the enhancement of malondialdehyde (MDA) content illustrated that CLOR exposure activated oxidative stress in exposed zebrafish embryos. Meanwhile, CLOR exposure also caused alterations in locomotive behavior in zebrafish embryos, including an increase in acetylcholinesterase (AChE) activity. Quantitative polymerase chain reaction (QPCR) results showed that the transcription of genes related to the central nervous system (CNS) development, namely, mbp, syn2a, α1-tubulin, gap43, shha, and elavl3, indicated that CLOR exposure could lead to neurotoxicity in zebrafish embryos. These results showed that CLOR exposure could cause developmental neurotoxicity in the early stages of zebrafish development and that CLOR might induce neurotoxicity by altering the expression of neuro-developmental genes, elevating AChE activity, and activating oxidative stress., 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 © 2023 Elsevier Ltd. All rights reserved.)

Altered sensitivity to the chronotropic and inotropic effects of catecholamines and reduction in β 1 /β 2 -adrenoceptor (β 1 /β 2 -AR) ratio were reported in failing and in senescent human heart, as well as in isolated atria and ventricle of rats submitted to stress. This was due to downregulation of β 1 -AR with or without up-regulation of β 2 -AR., Aims: To investigate the stress-induced behavior of β 1 -AR in the heart of mice expressing a non-functional β 2 -AR subtype. The guiding hypothesis is that the absence of β 2 -AR signaling will not affect the behavior of β 1 -AR during stress and that those are independent processes., Materials and Methods: The chronotropic and inotropic responses to β-AR agonists in isolated atria of stressed mice expressing a non-functional β 2 -AR were analyzed. The mRNA and protein expressions of β 1 - and β 2 -AR were also determined., Key Findings: No deaths were observed in mice under stress protocol. Atria of stressed mice displayed reduced sensitivity to isoprenaline compared to the controls, an effect that was abolished by the β 2 - and β 1 -AR antagonists 50 nM ICI118,551 and 300 nM CGP20712A, respectively. Sensitivity and maximum response to the β-agonists dobutamine and salbutamol were not altered by stress or ICI118,551. The responses to dobutamine and salbutamol were prevented by CGP20712A. The expression of β 1 -AR was reduced at protein levels., Significance: Collectively, our data provide evidence that the cardiac β 2 -AR is not essential for survival in a stressful situation and that the stress-induced reduction of β 1 -AR expression was independent of the β 2 -AR presence., Competing Interests: Declaration of competing interest There are no conflicting interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Myocardial infarction (MI) continues to be an important issue in healthcare systems worldwide, leading to high rates of morbidity and mortality. Despite ongoing efforts towards the development of preventive measures and treatments, addressing the challenges posed by MI remains difficult both in developed and developing countries. However, researchers recently investigated the potential cardioprotective effects of taraxerol utilizing an isoproterenol (ISO)-induced cardiotoxicity model among Sprague Dawley rats. Specifically, subcutaneous tissue injections consisting of 5.25 mg/kg or 8.5 mg/kg ISO were administered over two consecutive days as stimuli to induce cardiac injury. To investigate the possibility of preventing damage caused by ISO-induced cardiotoxicity by taraxerol treatment, five groups were formed: a normal control group (1% Tween 80), an ISO control group, an amlodipine group administered 5 mg/kg/day, and various doses of taraxerol. The study results showed that treatment significantly reduced cardiac marker enzymes. Additionally, pretreatment with taraxerol increased myocardial activity in SOD and GPx, leading to significant reductions in serum CK-MB levels along with MDA, TNF-α, and IL-6. Further histopathological analysis supported these observations, as treated animals had less cellular infiltration compared to untreated ones. These multifaceted findings suggest that oral administration of taraxerol could potentially protect hearts from ISO-caused damage by increasing endogenous antioxidant concentrations while decreasing pro-inflammatory cytokines.

When pathological hypertrophy progresses to heart failure (HF), the prognosis is often very poor. Therefore, it is crucial to find new and effective intervention targets. Here, myocardium-specific Trim44 knockout rats were generated using CRISPR-Cas9 technology. Cardiac phenotypic observations revealed that Trim44 knockout affected cardiac morphology at baseline. Rats with Trim44 deficiency exhibited resistance to cardiac pathological changes in response to stimulation via isoproterenol (ISO) treatment, including improvement of cardiac remodeling and dysfunction by morphological and functional observations, reduced myocardial fibrosis and reduced expression of molecular markers of cardiac stress. Furthermore, signal transduction validation associated with growth and hypertrophy development in vivo and in vitro demonstrated that Trim44 deficiency inhibited the activation of signaling pathways involved in myocardial hypertrophy, especially response to pathological stress. In conclusion, the present study indicates that Trim44 knockout attenuates ISO-induced pathological cardiac remodeling through blocking the AKT/mTOR/GSK3β/P70S6K signaling pathway. This is the first study to demonstrate the function and importance of Trim44 in the heart at baseline and under pathological stress. Trim44 could be a novel therapeutic target for prevention of cardiac hypertrophy and HF., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)

Cardiac hypertrophy is accompanied by increased myocardial oxidative stress, and whether naringenin, a natural antioxidant, is effective in the therapy of cardiac hypertrophy remains unknown. In the present study, different dosage regimens (25, 50, and 100 mg/kg/d for three weeks) of naringenin (NAR) were orally gavaged in an isoprenaline (ISO) (7.5mg/kg)-induced cardiac hypertrophic C57BL/6J mouse model. The administration of ISO led to significant cardiac hypertrophy, which was alleviated by pretreatment with naringenin in both in vivo and in vitro experiments. Naringenin inhibited ISO-induced oxidative stress, as demonstrated by the increased SOD activity, decreased MDA level and NOX2 expression, and inhibited MAPK signaling. Meanwhile, after the pretreatment with compound C (a selective AMPK inhibitor), the anti-hypertrophic and anti-oxidative stress effects of naringenin were blocked, suggesting the protective effect of naringenin on cardiac hypertrophy. Our present study indicated that naringenin attenuated ISO-induced cardiac hypertrophy by regulating the AMPK/NOX2/MAPK signaling pathway.

Aims: The objective of this study is to identify mechanisms for adipose stromal vascular fraction's (SVF) restorative effects on vasodilation in aging-induced coronary microvascular disease (CMD). We hypothesize that reactive oxygen species (ROS) diminish β1-adrenergic receptor (β1ADR)- and flow-mediated dilation (FMD) in coronary arterioles, reversible by SVF and adipose-derived stem cells (ADSCs). Results: SVF attenuates aging-induced chronic accumulation of ROS and pro-oxidant gene and protein expression with enhancement of antioxidant gene and protein expression and glutathione, but not nitric oxide. ADSCs attenuate hydrogen peroxide while restoring nitric oxide and glutathione. Mass spectrometry of SVF- and ADSC-conditioned media reveals abundant antioxidant proteins suggesting a paracrine mechanism. FMD and β1ADR-mediated dilation diminished with aging, restored with SVF and ADSCs. FMD was restored by a switch in the acute signaling mediator from hydrogen peroxide in aging to peroxynitrite with SVF and ADSCs. Vasorelaxation to β1ADR-agonism was mechanistically linked with hydrogen peroxide, nitric oxide, and glutathione. Exogenous ROS eliminates isoproterenol-mediated dilation in youth that is blocked by inhibition of pro-desensitization and internalization proteins while nitric oxide enhances isoproterenol-mediated dilation in aging. Innovation: We introduce a novel mechanism by which ROS impacts β1ADR trafficking: the ROS/RNS-β1ADR desensitization and internalization axis. Aging-induced ROS shunts β1ADR from the plasma membrane into endosomes. SVF reduces oxidative burden, restoring functional β1ADR. Conclusions: SVF (and ADSCs to a lesser extent) reduce oxidative stress, and restore flow- and β1ADR-mediated vasodilation in aging. SVF represents a promising therapeutic strategy for CMD by addressing root cause of pathology; that is, oxidative stress-mediated hyperconstriction. Antioxid. Redox Signal . 38, 261-281.

Scopoletin is a phenolic coumarin isolated from a variety of plants and was originally used to treat various diseases including arthritis as well as bone-related diseases. The goal of this study was to determine scopoletin's therapeutic potential in an animal model of myocardial infarction induced with ISO. There were five groups of albino male rats. Group I (control) animals were orally treated with olive oil. Group II (scopoletin) animals were pre-treated orally with a 50-mg dosage of scopoletin for 28 days. Group III (ISO-treated) animals were treated with 85 mg/kg of ISO subcutaneously for 2 consecutive days (29th and 30th day). Group IV (scopoletin and ISO) animals were pre-treated orally with 25 mg of scopoletin for 28 days before exposure to ISO. Group V (scopoletin and ISO) animals were pre-treated with 50 mg of scopoletin for 28 days before exposure to ISO. In the ISO-administered animals, a wider heart-to-body weight ratio, a higher heart weight, higher cardiac diagnostic markers, higher MDA levels and related antioxidant levels, inflammatory, and apoptotic markers were observed. Scopoletin pre-treatment with ISO (25 and 50 mg/kg b.wt) significantly reduced heart-to-body weight ratio, cardiac diagnostic markers, MDA, inflammatory markers, and apoptotic markers. Meantime, a pre-treatment with scopoletin increased the levels of antioxidant enzymes. Inflammation and necrosis were observed in the histopathology of heart tissue of ISO-treated animals and these histopathological conditions were reversed by scopoletin pretreatment. The antioxidant and anti-inflammatory properties of ISO-treated rats were shown to be increased by scopoletin, showing its therapeutic potential against cardiovascular diseases. Through the use of its antioxidant and anti-inflammatory properties, scopoletin exhibited anti-myocardial infarction properties. However, further preclinical studies will be required to demonstrate the mechanism of action of scopoletin involved in anti-myocardial infarction., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The study was conducted to determine whether corosolic acid could protect the myocardium of diabetic rats from damage caused by isoproterenol (ISO) and, if so, how peroxisome proliferator-activated receptor gamma (PPAR-γ) activation might contribute into this protection. Diabetes in the rats was induced by streptozotocin (STZ), and it was divided into four groups: the diabetic control group, diabetic rats treated with corosolic acid, diabetic rats treated with GW9662, and diabetic rats treated with corosolic acid plus GW9662. The study was carried out for 28 days. The diabetic control and ISO control groups showed a decrease in mean arterial pressure (MAP) and diastolic arterial pressure (DAP) and an increase in systolic arterial pressure (SAP). The rat myocardium was activated by corosolic acid treatment, which elevated PPAR-γ expression. A histopathological analysis showed a significant reduction in myocardial damage by reducing myonecrosis and edema. It was found that myocardial levels of CK-MB and LDH levels were significantly increased after treatment with corosolic acid. By decreasing lipid peroxidation and increasing endogenous antioxidant levels, corosolic acid therapy showed a significant improvement over the ISO diabetic group. In conclusion, our results prove that corosolic acid can ameliorate ISO-induced acute myocardial injury in rats. Based on these results, corosolic acid seems to be a viable new target for the treatment of cardiovascular diseases and other diseases of a similar nature.

We aimed to explore whether superfluous sympathetic activity affects myoblast differentiation, fusion, and myofiber types using a continuous single-dose isoprenaline exposure model in vitro and to further confirm the role of distinct NFATs in ISO-mediated effects. Compared with delivery of single and interval single, continuous single-dose ISO most obviously diminished myotube size while postponing myoblast differentiation/fusion in a time- and dose-dependent pattern, accompanied by an apparent decrease in nuclear NFATc1/c2 levels and a slight increase in nuclear NFATc3/c4 levels. Overexpression of NFATc1 or NFATc2, particularly NFATc1, markedly abolished the inhibitory effects of ISO on myoblast differentiation/fusion, myotube size and Myh7 expression, which was attributed to a remarkable increase in the nuclear NFATc1/c2 levels and a reduction in the nuclear NFATc4 levels and the associated increase in the numbers of MyoG and MEF2C positive nuclei within more than 3 nuclei myotubes, especially in MEF2C. Moreover, knockdown of NFATc3 by shRNA did not alter the inhibitory effect of ISO on myoblast differentiation/fusion or myotube size but partially recovered the expression of Myh7, which was related to the slightly increased nuclear levels of NFATc1/c2, MyoG and MEF2C. Knockdown of NFATc4 by shRNA prominently increased the number of MyHC +, MyoG or MEF2C + myoblast cells with 1 ~ 2 nuclei, causing fewer numbers and smaller myotube sizes. However, NFATc4 knockdown further deteriorated the effects of ISO on myoblast fusion and myotube size, with more than 5 nuclei and Myh1/2/4 expression, which was associated with a decrease in nuclear NFATc2/c3 levels. Therefore, ISO inhibited myoblast differentiation/fusion and myotube size through the NFAT-MyoG-MEF2C signaling pathway., (© 2023. The Author(s).)

The inhibitory effect of growth hormone (GH) on adipose tissue growth and the stimulatory effect of GH on lipolysis are well known, but the mechanisms underlying these effects are not completely understood. In this study, we revisited the effects of GH on adipose tissue growth and lipolysis in the lit/lit mouse model. The lit/lit mice are GH deficient because of a mutation in the GH releasing hormone receptor gene. We found that the lit/lit mice had more subcutaneous fat and larger adipocytes than their heterozygous lit/+ littermates and that these differences were partially reversed by 4-week GH injection. We also found that GH injection to the lit/lit mice caused the mature adipose tissue and adipocytes to reduce in size. These results demonstrate that GH inhibits adipose tissue growth at least in part by stimulating lipolysis. To determine the mechanism by which GH stimulates lipolysis, we cultured adipose tissue explants and adipocytes derived from lit/lit mice with GH and/or isoproterenol, an agonist of the beta-adrenergic receptors. These experiments showed that whereas isoproterenol, expectedly, stimulated potent lipolysis, GH, surprisingly, had no effect on basal lipolysis or isoproterenol-induced lipolysis in adipose tissue explants or adipocytes. We also found that both isoproterenol-induced lipolysis and phosphorylation of hormone-sensitive lipase were not different between lit/lit and lit/+ mice. Taken together, these results support the conclusion that GH has lipolytic effect in mice but argue against the notion that GH stimulates lipolysis by directly acting on adipocytes or by enhancing β-adrenergic receptors-mediated lipolysis., 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., (Copyright © 2023 Zhao and Jiang.)

Calanus oil, an oil extracted from the marine crustacean Calanus finmarchicus, is one of the richest sources of omega-3 and poly-unsaturated fatty acids. Although calanus oil has been shown to have a significant anti-hypertensive, anti-inflammatory, anti-fibrotic and anti-obesity effects in various cardiovascular diseases, but little is known about its effect on pathological cardiac hypertrophy. Thus, the present study was carried out to evaluate the therapeutic effect of calanus oil on cardiac hypertrophy. Cardiac hypertrophy was induced by subcutaneous injections with isoproterenol (5 mg/kg b.w) for 14 consecutive days. Calanus oil (400 mg/kg) was given orally for 4 weeks. Cardiac pathological remodeling was evaluated by echocardiography, after which morphometric, biochemical, histological and ultrastructural analyses were performed. Calanus oil treatment significantly ameliorated isoproterenol-induced structural and functional alterations in echocardiography. Calanus oil also reduced the relative heart weight, significantly decreased the elevated cardiac enzymes (LDH and CK-MB) and the lipid peroxidation marker (MDA), augmented the myocardial antioxidant status (TAC), and ameliorated the histopathological and ultrastructural changes in cardiac tissues and prevented interstitial collagen deposition. The present study, for the first time, provided morphometric, biochemical, histological and ultrastructural evidences supporting the promising anti-hypertrophic effect of calanus oil against ISO-induced cardiac hypertrophy. This anti-hypertrophic effect of calanus oil is via regulating myocardial remodeling and oxidative stress. Therefore, it could be used as potential pharmacological intervention in the management of cardiac hypertrophy.

At present, cardiovascular disorders are the most prominent factors for the high morbidity rate globally. The occurrence of myocardial infarction followed by myocardial ischemia is the important cause of high death rates. Various medical treatments are available, yet the mortality and morbidity rate is high. In the present investigation, the cardioprotective property of fraxetin (Fx) is evaluated in myocardial infarction-induced experimental rats. Fraxetin, a phytochemical known as coumarin isolated from Fraxinus rhynchophylla. Fraxetin has numerous pharmacological activities including antioxidant, apoptosis inhibitor, anti-inflammatory, and antimicrobial agent. The experimental mice were split into 4 groups each comprising six animals. Group I was considered the control group; 0.1% NaCl solution was given as dosage. Group II received only Fx; group III was treated with ISO. Group IV was treated with Fx followed by ISO to induce myocardial infarction. In ISO administrated rats, there were changes in the heart weight, activities of cardiac markers, transmembrane protein activity, antioxidant enzymes, pro-inflammatory proteins, lipid profile, and myocardial structures. Pre-treatment of fraxetin in group IV experimental rats resulted in decreased cardiac weight, diminished level of cardiac markers (cardiac troponin T (cTnT), creatine kinase, creatine kinase-MB, and cardiac troponin I (cTnI)), reduced level of oxidative stress biomarkers (LOOH and TBARS) in the plasma and cardiac tissue, amplified level of enzymes in antioxidant defense system (catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GPx)) in the plasma and heart tissue, and elevated level of ATPase activities. The histopathological studies also revealed the potent activity of fraxetin in protecting the cardiac tissues from inflammation and damage. ISO-administrated experimental rats treated with fraxetin exhibit increased antioxidants activity and decreased free radicals. Our study revealed that the administration of fraxetin significantly reduced the extent of myocardial damage during myocardial infarction in rats caused by isoproterenol. Thus, the results prove the cardioprotective effect of fraxetin in MI-induced rats., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: To investigate whether peroxisome proliferator-activated receptor γ-coactivator-1α/nuclear respiratory factor 1 (PGC-1α/NRF1) activity can protect mitochondrial function in the setting of cardiac hypertrophy and improve cardiomyocyte energy metabolism., Methods: Cardiac hypertrophy was modeled in H9c2 cells treated with isoproterenol (ISO) to assess the effects of Shenge San (, SGS) on cell viability and mitochondrial membrane potential. We assessed mitochondrial complex mRNA levels and mitochondrial oxidative phosphorylation factor mRNA and protein levels., Results: Compared with the 100 μM ISO group, cell size was significantly decreased in the 0.3 mg/mL SGS and 20 μM ZLN005 (PGC-1α activator) groups ( < 0.01). Compared with the SGS (0.3) +ISO group, we observed lower phosphorylated adenosine monophosphate-activated kinase (AMPK) protein levels in the ISO and ZLN005+SGS+ISO groups ( < 0.01). Compared with the compound C group, SGS significantly increased PGC-1α expression in ISO-induced cardiac hypertrophy cells ( < 0.01), and this was inhibited by compound C pretreatment ( < 0.05). Compared with the ISO group, the mitochondrial red-green fluorescence ratio increased in the 0.3 mg/mL SGS group ( < 0.05). mRNA levels of cytochrome c oxidase subunit 1 (CO1) in the ISO and compound C groups were lower than those in control group ( 0.01), and the mRNA levels of CO1 and ATP8 were significantly lower in the ISO and compound C groups versus control ( 0.01). Compared with the SGS (0.3) +ISO group, ATP synthetase subunit 8 (ATP8) mRNA was significantly decreased in the ISO group ( < 0.01) and compound C+SGS+ISO group ( < 0.05). Compared with the SGS (0.3) +ISO group, NRF1 mRNA levels were significantly decreased ( < 0.05) in the ISO and compound C+SGS+ISO groups., Conclusions: SGS can attenuate ISO-induced cardiomyocyte hypertrophy, restore the decrease in mitochondrial membrane potential, and upregulate PGC-1α/NRF1 levels. Notably, these effects can be blocked by AMPK inhibitor-compound C.

The current study investigated the preventive effect of 6-Shogaol on isoproterenol hydrochloride (ISO)-induced myocardial cardiac injury. 6-Shogaol (50 mg/kg b.w.) was administered for 14 days at pretreatment and ISO-induction (85 mg/kg b.w.) for the last two days (13th and 14th days) by subcutaneous injection. Cardiac markers in serum like creatine kinase (CK), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), cardiac troponins T (cTn T) and I (cTn I) increased in ISO-induced rats. Moreover, lipid peroxidative markers like thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were raised, and the activities/level of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and reduced glutathione (GSH) were diminished in ISO-treated heart tissue. In addition, inflammatory and nuclear respiratory factor (Nrf)-2 signalling molecules were upregulated in ISO-induced ischemic rats. 6-Shogaol pretreatment decreased the activities of cardiac and lipid peroxidative markers and enhanced the antioxidant status in ISO-induced cardiac injury rats. Further, 6-Shogaol pretreatment inhibited serum inflammatory markers: tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), nuclear factor-kappaB (NF-κB), Nrf-2 molecule and heme oxygenase (HO)-1 in ISO-induced cardial damage rats. We noticed the effect of 6-Shogaol inhibited pro-apoptotic genes like B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), Fas, caspase-3, -8, -9, cytochrome C, and inflammatory genes and increased Bcl-2 expression in ISO-treated rats. The cardioprotective activity of 6-Shogaol in rats with ISO-induced myocardial damage may be due to its ability to reduce oxidative stress, inflammation, and apoptosis, perhaps via the Nrf-2/HO-1 signalling pathway.

Cardiovascular diseases are the main cause of death worldwide. Recent studies have revealed the influence of histone-modifying enzymes in cardiac remodeling and heart dysfunction. The Set7 methyltransferase regulates the expression of several genes through the methylation of histones and modulates the activity of non-histone proteins. However, the role of Set7 in cardiac remodeling and heart dysfunction remains unknown. To address this question, wild-type (WT) and Set7 knockout (KO) male mice were injected with isoproterenol or saline. WT mice injected with isoproterenol displayed a decrease in Set7 activity in the heart. In addition, WT and Set7 KO mice injected with isoproterenol exhibited cardiac hypertrophy. Interestingly, Set7 deletion exacerbated cardiac hypertrophy in response to isoproterenol but attenuated myocardial fibrosis. Echocardiograms revealed that WT mice injected with isoproterenol had lowered ejection fractions and fractional shortening, and increased E'-wave deceleration time and E/A ratio compared with their controls. Conversely, Set7 KO mice did not show alteration in these parameters in response to isoproterenol. However, prolonged exposure to isoproterenol induced cardiac dysfunction both in WT and Set7 KO mice. Both isoproterenol and Set7 deletion changed the transcriptional profile of the heart. Moreover, Set7 deletion increased the expression of Pgc1α and mitochondrial DNA content in the heart, and reduced the expression of cellular senescence and inflammation markers in response to isoproterenol. Taken together, our data suggest that Set7 deletion attenuates isoproterenol-induced myocardial fibrosis and delays heart dysfunction, suggesting that Set7 plays an important role in cardiac remodeling and dysfunction in response to stress., (© 2022 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Inflammatory cytokines and non-esterified fatty acids (NEFAs) are obesity-linked factors that disturb insulin secretion. The aim of this study was to investigate whether pancreatic adipose tissue (pWAT) is able to generate a NEFA/cytokine overload within the pancreatic environment and as consequence to impact on insulin secretion. Pancreatic fat is a minor fat depot, therefore we used high-fat diet (HFD) feeding to induce pancreatic steatosis in mice. Relative Adipoq and Lep mRNA levels were higher in pWAT of HFD compared to chow diet mice. Regardless of HFD, Adipoq and Lep mRNA levels of pWAT were at least 10-times lower than those of epididymal fat (eWAT). Lipolysis stimulating receptors Adrb3 and Npr1 were expressed in pWAT and eWAT, and HFD reduced their expression in eWAT only. In accordance, HFD impaired lipolysis in eWAT but not in pWAT. Despite expression of Npr mRNA, lipolysis was stimulated solely by the adrenergic agonists, isoproterenol and adrenaline. Short term co-incubation of islets with CD/HFD pWAT did not alter insulin secretion. In the presence of CD/HFD eWAT, glucose stimulated insulin secretion only upon isoproterenol-induced lipolysis, i.e. in the presence of elevated NEFA. Isoproterenol augmented Il1b and Il6 mRNA levels both in pWAT and eWAT. These results suggest that an increased sympathetic activity enhances NEFA and cytokine load of the adipose microenvironment, including that of pancreatic fat, and by doing so it may alter beta-cell function., (© 2022. The Author(s).)

Cardiomyocytes have been differentiated from various stem cells such as human embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC), but it is difficult to produce mature cardiomyocytes. We showed rat hair-follicle-associated pluripotent (HAP) stem cells have pluripotency and produced mature beating cardiomyocyte sheets differentiated from rat HAP stem cells. The upper parts of rat vibrissa hair follicles were cultured in 10% FBS DMEM and stained with antibodies of the ectoderm, mesoderm, endoderm system to show the differentiation of multiple cell types. Moreover, HAP stem cells were cultured under three different conditions to decide the most suitable culture conditions for making beating cardiomyocyte sheets. The beating cardiomyocyte sheets were shown to be mature by staining sarcomere structures. Isoproterenol alone and the combination of isoproterenol, activin A, bone morphogenetic protein 4 (BMP4) and basic fibroblast growth factor (bFGF) effectively induced beating long-fiber cardiomyocytes, which formed beating sheets, only in the presence of all four agents. Flexible substrates were essential for the differentiation of sheets of mature beating cardiomyocytes for HAP stem cells. The features of the cardiomyocytes differentiated from HAP stem cells demonstrate they have clinical potential for heart regeneration., (© 2022. The Author(s) under exclusive licence to The Japanese Society for Clinical Molecular Morphology.)

Earlier studies reported that long-term treatment with thymoquinone (TQ) at a high dose (20 mg/kg) exerts a cardioprotective effect against isoproterenol (ISO)-triggered myocardial infarction (MI) in rats. In the present study, we tested the hypothesis that TQ, as a potent molecule, can exhibit cardioprotective effects at the lower dose for a short-term regimen. The rats were administered with TQ (5 mg/kg, intraperitoneal) at the 4 h interval for 2 days. ISO (100 mg/kg/day, subcutaneous) was given for 2 days to produce MI. ISO challenge results in deformation in ECG wave front, elevated left ventricular (LV) end-diastolic pressure, and reduced LVdP/dtmax and LVdP/dtmin. The levels of the cardiac biomarker in serum, such as creatine kinase MB, alanine aminotransferase, and aspartate aminotransferase, were increased. In the myocardium, a rise in malonaldehyde and decreased superoxide dismutase, glutathione, and catalase contents were observed. Furthermore, increased levels of tumor necrotic factor-α, interleukin-6, and interleukin-1β were observed in the myocardium. TQ pretreatment significantly normalized alterations in hemodynamic parameters, strengthened the antioxidant defense system, and decreased the contents of pro-inflammatory cytokines and hepatic enzymes as compared to the ISO group. Based on the results, TQ appears to be cardioprotective at low doses, and effective even administered for a shorter duration.

Acute cardiac pathologies represent one of the leading causes of death, while iron metabolism is recognized to be implicated in reactive oxygen species production, lipid peroxidation, and inflammation. The aim of the present study was to assess iron chelation effects in isoproterenol (ISO) induced acute cardiac stress. We divided male Wistar rats into preventive and secondary treatment groups, with the active arm consisting in deferiprone (DFP), a lipid permeable chelator. Mortality of ISO was 10-18.18% in both preventive and secondary groups. We analyzed serum and myocardial tissue parameters of inflammation, iron dynamics, and lipid peroxidation, accompanied by ultramicroscopy, histological, and ultrasound-derived parameters of left ventricular function. Results reveal that ISO-mediated lipid peroxidation and inflammation are alleviated by administration of DFP, with negligible effect on systemic ferroregulation dynamics and global ventricular function (as assessed by ultrasound). DFP administration after cardiovascular stress is associated with a decrease in lipid peroxidation and inflammation, without an improvement in gross left ventricular parameters.

Purpose: To investigate the effect of tension on the inflammatory response of human periodontal ligament cells (PDLCs) induced by isoproterenol (ISO) and its molecular mechanism., Methods: Human PDLCs were cultured in vitro and stimulated with a certain concentration of ISO(0.01, 0.1, 1 μmol/L) for 24 h. Cyclic tensile strain with different degrees of elongation (5%, 10% and 15%) were applied. The expression of IL-1β and IL-6 mRNA in PDLCs was detected by real-time quantitative PCR(RT-qPCR). The protein expression of p-PERK, PERK, p-eIF2α, eIF2α and ATF4 related to ER stress was detected by Western blot. The expression of PERK gene in PDLCs was knocked down by cell transfection technique, and the expression of IL-1β and IL-6 mRNA in PDLCs with low expression of PERK was detected by RT-qPCR under the stimulation of ISO and low magnitude tension. Statistical analysis was conducted with SPSS 22.0 software package., Results: ISO induction could significantly up-regulate the IL-1β and IL-6 mRNA expression in PDLCs(P＜0.05). Compared with the control group, the expression of IL-1β and IL-6 mRNA in PDLCs induced by ISO was inhibited by low magnitude tension, and the difference was statistically significant(P＜0.05). Western blot results showed that low magnitude tension could inhibit the ISO-stimulated phosphorylation of PERK and eIF2α and the expression of ATF4（P＜0.05）. Compared with the negative control group, IL-1β and IL-6 mRNA expression was decreased in the ISO-stimulated PDLCs silenced by PERK gene., Conclusions: Tension with 5% degrees of elongation may inhibit ISO-stimulated periodontal inflammatory response through endoplasmic reticulum stress pathway.

The study explored the cardioprotective role of the methanolic leaf extract of Nelumbo nucifera and nuciferine against isoproterenol-induced myocardial infarction (MI) in Wistar rats. Pretreatment with leaf extract and nuciferine (200 and 20 mg/kg body weight, respectively) against MI induced by isoproterenol (85 mg/kg body weight) significantly decreased heart weight; levels of cardiac markers such as lactate dehydrogenase and creatine kinase-MB were similar to those in controls. The treatment significantly increased the content of endogenous antioxidants and decreased lipid peroxidation in all treated groups. Treated groups showed a significant reduction in heartbeats per minute as compared with the MI-induced positive control. The MI-induced group showed pathological implications such as tachycardia, left atrial enlargement, and anterolateral ST-elevated MI, which were absent in treated groups. Histology confirmed that the leaf extract and nuciferine prevented structural abnormality and inflammation in heart and liver tissues of treated groups. On in silico analysis, nuciferine showed stronger binding interaction with both β 1 and β 2 adrenergic receptors than isoproterenol. Hence, the leaf extract of N. nucifera and nuciferine could be used as plant-based cardioprotective agents., (© 2021 International Union of Biochemistry and Molecular Biology, Inc.)

T1R3 is a class C G protein-coupled receptor family member that forms heterodimeric umami and sweet taste receptors with T1R1 and T1R2, respectively, in the taste cells of taste buds. T1R3 is expressed in 3T3-L1 cells in homomeric form and negatively regulates adipogenesis in a Gαs-dependent but cAMP-independent manner. Although T1R3 expression is markedly upregulated during adipogenesis, its physiological role in mature adipocytes remains obscure. Here, we show that stimulation of T1R3 with sucralose or saccharin induces microtubule disassembly in differentiated 3T3-L1 adipocytes. The effect was reproduced by treatment with cholera toxin or isoproterenol but not with forskolin. Treatment with sucralose or saccharin for 3 h inhibited insulin-stimulated glucose uptake by 32% and 45% in differentiated adipocytes, respectively, similar to the inhibitory effect of nocodazole (by 33%). Isoproterenol treatment inhibited insulin-stimulated glucose transport by 26%, whereas sucralose did not affect the intrinsic activity of the glucose transporter, indicating that it inhibited insulin-induced GLUT4 translocation to the plasma membrane. Immunostaining analysis showed that insulin-stimulated GLUT4 accumulation on the plasma membrane was abrogated in sucralose-treated cells, in association with depolymerization of microtubules. Sucralose-mediated inhibition of GLUT4 translocation was reversed by the overexpression of dominant-negative Gαs (Gαs-G226A) or knockdown of Gαs. Additionally, membrane fractionation analysis showed that sucralose treatment reduced GLUT4 levels in the plasma membrane fraction from insulin-stimulated adipocytes. We have identified a novel non-gustatory role for homomeric T1R3 in adipocytes, and activation of the T1R3 receptor negatively regulates insulin action of glucose transport via Gαs-dependent microtubule disassembly.

Myocardial hypertrophy is a pathological feature of many heart diseases. This is a complex process involving all types of cells in the heart and interactions with circulating cells. This study is aimed at identifying the differentially expressed proteins (DEPs) in myocardial hypertrophy rats induced by isoprenaline (ISO) and treated with novel peptide Athycaltide-1 (ATH-1) and exploring the mechanism of its improvement. ITRAQ was performed to compare the three different heart states in control group, ISO group, and ATH-1 group. Pairwise comparison showed that there were 121 DEPs in ISO/control (96 upregulated and 25 downregulated), 47 DEPs in ATH-1/ISO (27 upregulated and 20 downregulated), and 116 DEPs in ATH-1/control (77 upregulated and 39 downregulated). Protein network analysis was then performed using the STRING software. Functional analysis revealed that Hspa1 protein, oxidative stress, and MAPK signaling pathway were significantly involved in the occurrence and development of myocardial hypertrophy, which was further validated by vivo model. It is proved that ATH-1 can reduce the expression of Hspa1 protein and the level of oxidative stress in hypertrophic myocardium and further inhibit the phosphorylation of p38 MAPK, JNK, and ERK1/2., Competing Interests: Athycaltide-1 has obtained a granted patent (ZL201711418314.3) in China with Liying Hao, Jingyuan Li, Zhuo Li, Ze Kang and Siqi Wang as inventors. The authors have no other conflicts of interest., (Copyright © 2022 Xi Zheng et al.)

Cardiovascular risk factors have attracted increasing attention in recent years with the acceleration of population aging, amongst which cardiac hypertrophy is the initiating link to heart failure. Pirfenidone is a promising agent for the treatment of idiopathic pulmonary fibrosis and has recently proven to exert inhibitory effects on the inflammatory response. This study proposes to explore the potential pharmacological action of Pirfenidone in treating cardiac hypertrophy in a rodent model. Four groups of mice were used in the present study: the control, ISO (5 mg/kg/day) for 7 days, Pirfenidone (200 mg/kg/day) for 14 days, and Spironolactone (SPI) (200 mg/kg/day) for 14 days groups. Increased heart weight index, left ventricle (LV) weight index, LV wall thickness, declined LV volume, and elevated serum levels of CK-MB, AST, and LDH were observed in ISO-challenged mice, all of which were dramatically reversed by the administration of Pirfenidone or SPI. Furthermore, an elevated cross-sectional area of cardiomyocytes in the wheat germ agglutinin (WGA) staining of heart cross-sections, upregulated atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), β Myosin Heavy Chain (β-MHC), and excessively released tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) in cardiac tissues were observed in the ISO group but greatly alleviated by Pirfenidone or SPI. Lastly, the promoted expression levels of p-JAK-2/JAK-2 and p-STAT3/STAT-3 in the cardiac tissues of ISO-challenged mice were significantly repressed by Pirfenidone or SPI. Collectively, our data reveals a therapeutic property of Pirfenidone on ISO-induced cardiac hypertrophy in mice.

Total body fat and central fat distribution are heritable traits and well-established predictors of adverse metabolic outcomes. Lipolysis is the process responsible for the hydrolysis of triacylglycerols stored in adipocytes. To increase our understanding of the genetic regulation of body fat distribution and total body fat, we set out to determine if genetic variants associated with body mass index (BMI) or waist-hip-ratio adjusted for BMI (WHRadjBMI) in genome-wide association studies (GWAS) mediate their effect by influencing adipocyte lipolysis. We utilized data from the recent GWAS of spontaneous and isoprenaline-stimulated lipolysis in the unique GENetics of Adipocyte Lipolysis (GENiAL) cohort. GENiAL consists of 939 participants who have undergone abdominal subcutaneous adipose biopsy for the determination of spontaneous and isoprenaline-stimulated lipolysis in adipocytes. We report 11 BMI and 15 WHRadjBMI loci with SNPs displaying nominal association with lipolysis and allele-dependent gene expression in adipose tissue according to in silico analysis. Functional evaluation of candidate genes in these loci by small interfering RNAs (siRNA)-mediated knock-down in adipose-derived stem cells identified ZNF436 and NUP85 as intrinsic regulators of lipolysis consistent with the associations observed in the clinical cohorts. Furthermore, candidate genes in another BMI-locus (STX17) and two more WHRadjBMI loci (NID2, GGA3, GRB2) control lipolysis alone, or in conjunction with lipid storage, and may hereby be involved in genetic control of body fat. The findings expand our understanding of how genetic variants mediate their impact on the complex traits of fat storage and distribution., (© 2022. The Author(s).)

Uncoupling protein 1 (UCP1) was found exclusively in the inner membranes of the mitochondria of brown adipose tissue (BAT). We found that UCP1 was also expressed in heart tissue and significantly upregulated in isoproterenol (ISO)-induced acute myocardial ischemia (AMI) rat model. The present study is to determine the underlying mechanism involved in the UCP1 upregulation in ISO-induced AMI rat model. The Ucp1 -/- rats were generated by CRISPR-Cas9 system and presented decreased BAT volume. 2-months old Sprague Dawley (SD) wild-type (WT) and Ucp1 -/- rats were treated with ISO intraperitoneally 30 mg/kg once a day for 3 consecutive days to establish AMI model. In saline group, the echocardiographic parameters, serum markers of myocardial injury cardiac troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB), oxidant malondialdehyde (MDA), antioxidant superoxide dismutase (SOD) or fibrosis were comparable between WT and Ucp1 -/- rats. ISO treatment induced worse left ventricle (LV) hypertrophy, myocardial fibrosis, increased higher cTnI, CK-MB and MDA and decreased lower SOD level in Ucp1 -/- rats compared with that of WT rats. Ucp1 -/- rats also presented lower myocardial phosphocreatine (PCr)/ATP-ratio, which demonstrated worse cardiac energy regulation defect. ISO treatment induced the phosphorylation of AMP-activated protein kinase (AMPK) activation, subsequently the phosphorylation of mammalian target of rapamycin (mTOR) inhibition and peroxisome proliferators-activated receptor α (PPARα) activation in WT rats, whereas activation of AMPK/mTOR/PPARα pathways significantly inhibited in Ucp1 -/- rats. To sum up, UCP1 knockout aggravated ISO-induced AMI by inhibiting AMPK/mTOR/PPARα pathways in rats. Increasing UCP1 expression in heart tissue may be a cytoprotective therapeutic strategy for AMI., (© 2021. The Author(s).)

Typically, healthy cardiac tissue utilizes more fat than any other organ. Cardiac hypertrophy induces a metabolic shift leading to a preferential consumption of glucose over fatty acids to support the high energetic demand. Calorie restriction is a dietary procedure that induces health benefits and lifespan extension in many organisms. Given the beneficial effects of calorie restriction, we hypothesized that calorie restriction prevents cardiac hypertrophy, lipid content changes, mitochondrial and redox dysregulation. Strikingly, calorie restriction reversed isoproterenol-induced cardiac hypertrophy. Isolated mitochondria from hypertrophic hearts produced significantly higher levels of succinate-driven H 2 O 2 production, which was blocked by calorie restriction. Cardiac hypertrophy lowered mitochondrial respiratory control ratios, and decreased superoxide dismutase and glutathione peroxidase levels. These effects were also prevented by calorie restriction. We performed lipidomic profiling to gain insights into how calorie restriction could interfere with the metabolic changes induced by cardiac hypertrophy. Calorie restriction protected against the consumption of several triglycerides (TGs) linked to unsaturated fatty acids. Also, this dietary procedure protected against the accumulation of TGs containing saturated fatty acids observed in hypertrophic samples. Cardiac hypertrophy induced an increase in ceramides, phosphoethanolamines, and acylcarnitines (12:0, 14:0, 16:0, and 18:0). These were all reversed by calorie restriction. Altogether, our data demonstrate that hypertrophy changes the cardiac lipidome, causes mitochondrial disturbances, and oxidative stress. These changes are prevented (at least partially) by calorie restriction intervention in vivo. This study uncovers the potential for calorie restriction to become a new therapeutic intervention against cardiac hypertrophy, and mechanisms in which it acts., (© 2021. The Author(s) under exclusive licence to University of Navarra.)

Background: Antioxidants are beneficial in myocardial infarction (MI). It is suggestive that Theobroma cacao (TC) with rich antioxidant properties can be of health benefits in myocardial injury., Aim: The study investigated the effect of Theobroma cacao on cardioprotection in isoproterenol-induced myocardial infarction in rats., Material and Methods: Male Wistar rats divided into four groups of 6 rats were used for the study. In group 1, 0.9% normal saline placebo was administered via oral gavage to the control. Group 2 was the MI induced group that was given 100 mg/kg body weight isoproterenol subcutaneously twice at an interval of 24 hours. Group 3 was administered TC for 2 weeks at 100 mg/kg bodyweight via the oral route. Group 4 was pretreated with TC (100 mg/kg) via oral route for 2 weeks, immediately followed by the administration of 100 mg/kg body weight isoproterenol subcutaneously twice at an interval of 24 hours. The rats were sacrificed using chloroform anesthesia, and blood samples collected via cardiac puncture. The serum was analyzed for troponin level, lactate dehydrogenase (LDH), and malondialdehyde (MDA) level., Results: The serum troponin, LDH, and MDA levels were found to be significantly (p<0.01) increased in the MI group compared with the control. Pretreatment with TC before MI induction significantly (p<0.01) prevented increased serum troponin, LDH, and MDA levels when compared with the MI group. There was also a significant (p<0.01) decrease in MDA in the TC group compared with the control., Conclusion: These results suggest that Theobroma cacao protects against isoproterenol-induced myocardial injury, possibly by preventing oxidative stress and consequent lipid peroxidation., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Manipulation of adrenergic signaling has been shown experimentally and clinically to affect hair follicle growth. In this study, we provide direct evidence that canonical cAMP/CRE-binding protein signaling through adrenergic receptors can regulate hair follicle stem cell (HFSC) activation and hair cycle. We found that CRE-binding protein activation is regulated through the hair cycle and coincides with HFSC activation. Both isoproterenol and procaterol, agonists of adrenergic receptors, show the capacity to activate the hair cycle in mice. Furthermore, deletion of ADRB2 receptor, which is thought to mediate sympathetic nervous system regulation of HFSCs, was sufficient to block HFSC activation. Downstream, stimulation of adenylyl cyclase with forskolin or inhibition of phosphodiesterase to increase cAMP accumulation or direct application of cAMP was each sufficient to promote HFSC activation and accelerate initiation of hair cycle. Genetic induction of a Designer Receptors Exclusively Activated by Designer Drug allele showed that G-protein coupled receptor/GαS stimulation, specifically in HFSCs, promoted the activation of the hair cycle. Finally, we provide evidence that G-protein coupled receptor/CRE-binding protein signaling can potentially act on HFSCs by promoting glycolytic metabolism, which was previously shown to stimulate HFSC activation. Together, these data provide mechanistic insights into the role of sympathetic innervation on HFSC function., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Aim: Ambient exposure of PM 2.5 from diesel exhaust (termed as diesel particulate matter [DPM]) can induce cardiotoxicity that can be manifested into myocardial ischemia/infarction, where the survival depends on mitochondrial function. The mechanism for DPM-induced mitochondrial dysfunction is yet to be elucidated and the consequential impact of impaired mitochondria on the severity of myocardial infarction (MI) has not been established. Materials and methods: Female Wistar rats were exposed to DPM (0.5 mg/ml) for 3 h daily (to achieve a PM 2.5 concentration of 250 µg/m 3 ) for 21 d trailed by an induction of MI using isoproterenol (ISO). Conclusion: DPM exposure altered the basal ECG pattern and increased heart weight (HW) to body weight (BW) ratio from control. Loss of mitochondrial quality in the cardiac tissue was observed in DPM exposed animals, measured via declined ETC enzyme activity, reduced ATP levels, high oxidative stress, low mitochondrial copy number, and low expression of the mitochondrial genes involved in mitophagy (PINK and PARKIN) and mitochondrial fusion (MFN-1). Subsequent induction of MI in DPM exposed animals (DPM + ISO) further deteriorated the normal sinus rhythm, accompanied by elevated plasma CK and LDH level, increased myocardial caspase activity, downregulation of Peroxisome proliferator-activated receptor-gamma coactivator (PGC1-α), transcription factor A (TFAM), DNA polymerase subunit gamma (POLG), and other mitochondrial quality control genes. Based on these results, we conclude that DPM alters the electrophysiology and ultrastructure of the heart that aggravates the MI-induced cardiotoxicity, where the diminished mitochondrial quality can be the potential contributor.

Aims: β-Arrestin2 signaling has emerged as a promising therapeutic target for the management of insulin resistance and related complications. Moreover, recent studies have shown that certain G protein-coupled receptor (GPCR) ligands can modulate β-arrestin2 signaling. The current study examined the effects of the β-blocker propranolol and a low dose of the agonist isoproterenol (L-D-ISOPROT) on β-arrestin2 signaling, insulin resistance, and cardiac remodeling in high-fructose, high-fat diet (HFrHFD)-fed mice. In addition, the effects of these agents were compared to those of the clinical antidiabetic agent, metformin., Materials and Methods: Insulin resistance was induced by HFrHFD feeding for 16 weeks. Mice were then randomly allocated to groups receiving propranolol, L-D-ISOPROT, metformin, or vehicle (control) for 4 weeks starting on week 13 of HFrHFD feeding. Survival rate, body weight, visceral fat weight, blood glucose, serum insulin, insulin resistance index, hepatic β-arrestin2 signaling, heart weight, left and right ventricular thicknesses, cardiac fibrosis severity, serum endothelin-1, cardiac cardiotrophin-1, and cardiac β-arrestin2 signaling were then compared among groups., Key Findings: HFrHFD for 16 weeks significantly increased insulin resistance index, cardiac fibrosis area, and serum endothelin-1, and reduced hepatic β-arrestin2 signaling, cardiac cardiotrophin-1, and cardiac β-arrestin2 signaling without significant changes in survival rate, body weight, visceral fat weight, heart weight, or left and right ventricular thicknesses. All three drugs reduced insulin resistance and cardiac remodeling parameters and enhanced β-arrestin2 signaling with variable efficacies., Significance: Propranolol and L-D-ISOPROT, like metformin, can reduce insulin-resistance and cardiac remodeling in HFrHFD-fed mice, possibly by upregulating β-arrestin2 signaling activity. Therefore, β-arrestin2-signaling modulation might be a promising strategy for insulin-resistance treatment., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Cell surface receptors including the epidermal growth factor receptor (EGFR) family and G-protein coupled receptors (GPCRs) play quintessential roles in physiology, and in diseases, including cardiovascular diseases. While downstream signaling from these individual receptor families has been well studied, the cross-talk between EGF and GPCR receptor families is still incompletely understood. Including members of both receptor families, the number of receptor and ligand combinations for unique interactions is vast, offering a frontier of pharmacologic targets to explore for preventing and treating disease. This molecular cross-talk, called receptor transactivation, is reviewed here with a focus on the cardiovascular system featuring the well-studied GPCR receptors, but also discussing less-studied receptors from both families for a broad understanding of context of expansile interactions, repertoire of cellular signaling, and disease consequences. Attention is given to cell type, level of chronicity, and disease context given that transactivation and comorbidities, including diabetes, hypertension, coronavirus infection, impact cardiovascular disease and health outcomes., (Copyright © 2021 Elsevier Inc. All rights reserved.)

CRISPR base editors are powerful tools for large-scale mutagenesis studies. This kind of approach can elucidate the mechanism of action of compounds, a key process in drug discovery. Here, we explore the utility of base editors in an early drug discovery context focusing on G-protein coupled receptors. A pooled mutagenesis screening framework was set up based on a modified version of the CRISPR-X base editor system. We determine optimized experimental conditions for mutagenesis where sgRNAs are delivered by cell transfection or viral infection over extended time periods (>14 days), resulting in high mutagenesis produced in a short region located at -4/+8 nucleotides with respect to the sgRNA match. The β2 Adrenergic Receptor (B2AR) was targeted in this way employing a 6xCRE-mCherry reporter system to monitor its response to isoproterenol. The results of our screening indicate that residue 184 of B2AR is crucial for its activation. Based on our experience, we outline the crucial points to consider when designing and performing CRISPR-based pooled mutagenesis screening, including the typical technical hurdles encountered when studying compound pharmacology., Competing Interests: The authors EAP, DY, JPF, AW, HSX and RS were Pfizer employees. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Cardiac fibrosis is the final event of heart failure and is associated with almost all forms of cardiovascular disease. Cardiac fibroblasts (CFs), a major cell type in the heart, are responsible for regulating normal myocardial function and maintaining extracellular matrix homeostasis in adverse myocardial remodeling. In this study, we found that C188-9, a small-molecule inhibitor of signal transducer and activator of transcription 3 (STAT3), exhibited an antifibrotic function, both in vitro and in vivo. C188-9 decreased transforming growth factor-β1-induced CF activation and fibrotic gene expression. Moreover, C188-9 treatment alleviated heart injury and cardiac fibrosis in an isoproterenol-induced mouse model by suppressing STAT3 phosphorylation and activation. These findings may help us better understand the role of C188-9 in cardiac fibrosis and facilitate the development of new treatments for cardiac fibrosis and other cardiovascular diseases., (© 2021 The Authors. FEBS Open Bio published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Cardiac hypertrophy is a common pathological process of various cardiovascular diseases and eventually develops into heart failure. This paper was aimed to study the different pathological characteristics exhibited by different mouse strains after hypertrophy stimulation. Two mouse strains, A/J and FVB/nJ, were treated with isoproterenol (ISO) by osmotic pump to induce cardiac hypertrophy. Echocardiography was performed to monitor heart morphology and function. Mitochondria were isolated from hearts in each group, and oxidative phosphorylation function was assayed in vitro. The results showed that both strains showed a compensatory enhancement of heart contractile function after 1-week ISO treatment. The A/J mice, but not the FVB/nJ mice, developed significant cardiac hypertrophy after 3-week ISO treatment as evidenced by increases in left ventricular posterior wall thickness, heart weight/body weight ratio, cross sectional area of cardiomyocytes and cardiac hypertrophic markers. Interestingly, the heart from A/J mice contained higher mitochondrial DNA copy number compared with that from FVB/nJ mice. Functionally, the mitochondria from A/J mice displayed faster O 2 consumption at state III with either complex I substrates or complex II substrate, compared with those from FVB/nJ mice. ISO treatment did not affect mitochondrial respiratory control rate (RCR), but significantly suppressed the ADP/O ratio generated from the complex II substrate in both strains. The ADP/O ratio generated from the complex I substrates in A/J mice declined by 50% after ISO treatment, whereas FVB/nJ mice were not affected. These results suggest that, compared with FVB/nJ mice, A/J mice possesses a poor integrity of mitochondrial respiratory chain that might contribute to its vulnerability to ISO-induced cardiac hypertrophy.

The skeletal muscle mass has been shown to be affected by catecholamines, such as epinephrine (Epi), norepinephrine (NE), and isoproterenol (ISO). On the other hand, lipopolysaccharide (LPS), one of the causative substances of sepsis, induces muscle wasting via toll-like receptors expressed in skeletal muscle. Although catecholamines are frequently administered to critically ill patients, it is still incompletely understood how these drugs affect skeletal muscle during critical illness, including sepsis. Herein, we examined the direct effects of catecholamines on LPS-induced skeletal muscle wasting using the C2C12 myoblast cell line. Muscle wasting induced by catecholamines and/or LPS was analyzed by the use of the differentiated C2C12 myotubes, and its underlying mechanism was explored by immunoblotting analysis, quantitative reverse transcription polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay (ELISA), and the TransAM kit for p-65 NF-κB. Epi augmented myosin heavy chain (MHC) protein loss and reduction of the myotube diameter induced by LPS. LPS induced C/EBPδ protein, Atrogin-1 and inteleukin-6 (IL-6), and these responses were potentiated by Epi. An IL-6 inhibitor, LMT28, suppressed the potentiating effect of Epi on the LPS-induced responses. NF-κB activity was induced by LPS, but was not affected by Epi and recombinant IL-6, and the NF-κB inhibitor, Bay 11-7082, abolished Atrogin-1 mRNA expression induced by LPS with or without Epi. NE and ISO also potentiated LPS-induced IL-6 and Atroign-1 mRNA expression. Carvedilol, a nonselective β-adrenergic receptor antagonist, suppressed the facilitating effects of Epi on the Atrogin-1 mRNA induction by LPS, and abolished the effects of Epi on the MHC protein loss in the presence of LPS. It was concluded that Epi activates the β-adrenergic receptors in C2C12 myotubes and the IL-6-STAT3 pathway, leading to the augmentation of LPS-induced activation of the NF-κB- C/EBPδ-Atrogin-1 pathway and to the exacerbation of myotube wasting., Competing Interests: The authors have declared that no competing interests exist.

Objectives: Comparative evaluation of cardioprotective activity of Gala and Fuji apple juice against isoprenaline induced cardiotoxicity in rats., Methods: Rats (125-150 g) were orally administered Gala (GA) and Fuji (FA) apple juice (3 mL/day, per oral) for 13 days. Myocardial injury was inducted on 14th and 15th day by the administration of Isoprenaline (85 mg/kg/day, subcutaneous)., Results: In treated group i.e. GA and FA, aspartate aminotransferase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), creatine kinase (CK), Troponin-I level and malondialdehyde (MDA) content was reduced while glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) level was significantly increased. Marked reduction in cholesterol, triglyceride, phospholipids, low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) was observed while high-density lipoprotein (HDL) level increased significantly. In tissue and serum total serum protein (TSP) level, Albumin, Globulin and A/G ratio increased very significantly in the treated group while the level of white blood corpuscles (WBC), haemoglobin (Hb), erythrocyte sedimentation rate (ESR), total fibrinogen (TF), bleeding time (BT), c-reactive protein (C-rP), red blood corpuscles (RBC), clotting time (CT) and prothrombin time (PT) showed a significant rise in the level. The level of Sialic acid, hexose, fucose and hexosamine was highly significantly increased, there was an increase in the level of K + and glycogen while a significant reduction in electrolyte and glucose level was observed when all these parameters were compared to Isoprenaline (ISO) group. The above findings were supported by histopathological examination of hearts. Cardioprotective activity was compared with standard drug, metoprolol. On comparative analysis of both juices, GA juices have found more effective when compared to FA juice., Conclusions: The study was concluded that Gala and Fuji apple possessed significant prophylactic and protective effects against Isoprenaline-induced cardiotoxicity in rats through maintaining inhibiting lipid peroxidation, endogenous antioxidant enzyme activities and cytokine levels., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Although there is accumulating evidence which suggests that the administration of ghrelin could be used to preserve cardiac function, delay the progression of heart failure post-myocardial infarction, and attenuate ventricular remodeling, there is still no definitive data that clearly highlights the mechanisms by which ghrelin exerts cardioprotective effects. The present study aimed to investigate whether ghrelin could affect nuclear factor erythroid 2-related factor-2 (Nrf2), heme oxygenase-1 (HO-1), and endothelial nitric oxide synthase (eNOS) expression and exert anti-inflammatory as well as antioxidant-like actions through this signaling pathway. Rats were assorted into four groups with 10 in each: Group I (Control), Group II (received ghrelin only), Group III (MI was induced by isoproterenol (ISO)), Group IV (MI was induced by isoproterenol and within 30 min of each ISO dose, rats received ghrelin; 100 μg /kg subcutaneously two times per day). We assessed the effects of acylated ghrelin on the biochemical changes, ECG parameters, heart rate, histopathological scoring and the mRNA expression of eNOS, Nrf2 (confirmed immunohistochemically) as well as HO-1 genes in the cardiac tissues. Nuclear factor-κB, tumor necrosis factor-α, interleukin-6, and inducible nitric oxide synthase were assessed as inflammatory markers. Ghrelin markedly improved the oxidative stress injury and inflammation, showed histological preservation of the cardiac muscle fibers morphology, ameliorated the ISO-induced ECG changes and caused a significant elevation in eNOS, HO-1, and Nrf2 expression. In conclusion, ghrelin exerts cardioprotective effect in ISO-induced myocardial infarction by promoting the eNOS/Nrf2/HO-1 pathway.