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The cyclin D1 (CCND1) gene, encodes the regulatory subunit of a holoenzyme that phosphorylates and inactivates the Rb protein. Cyclin D1 overexpression occurs in up to 50% of human breast cancers. Cyclin D1, governs the expression (1,3), processing (2), the secretion and the relative proportion of secreted non-coding RNA subtypes (miRNA, rRNA, tRNA, CDBox, scRNA, HAcaBox. scaRNA, piRNA) in human breast cancer and the secretion of piRNA (4). Through base-pairing to the complementary sequence in 3’ untranslated region (3’ UTR) of mRNA, miRNAs participate in diverse biological processes. A subset of miRNA regulate the ageing of innate and adaptive immune cells, which has been associated with breast cancer initiation, progression and therapy resistance. Immuno-miRs, ( miR-21 and miR-93), bind to the 3′-UTR region of mRNAs, and binding to- and or activate Toll-Like Receptor 8 (TLR8) in surrounding cells of the immune system. Exosomes which contain constituents of their cell of origin, including mRNA and miRNA are found in the tumor microenvironment and participate in therapy resistance, cancer metastasis and the metastatic niche. Herein, tet-inducible cyclin D1 shRNA knock down in MCF-7 breast cancer cells reduced MCF-7 cell proliferation and mammosphere formation. Exosomes isolated from wildtype and cyclin D1 knock-down MCF-7 cell culture media, showed that exosomes from cyclin D1 knock down cells decreased proliferation of both wildtype and cyclin D1 knock-down cells. Furthermore, wildtype exosomes partially reversed the cyclin D1 knock-down effects. Cyclin D1 knock-down exosomes decreased mammosphere formation of wildtype MCF-7 cells and wildtype exosomes increased mammosphere formation of cyclin D1 knock-down cells. miRNA profiles within the exosomes, showed that cyclin D1 regulated the abundance of miRNA within exosomes. >85% of the cyclin D1-induced exosome miRNA transcripts were the immune-mIR, miR21. hsa-mir-21 which has documented tumor promoting function, was the most enriched miRNAs in cyclin D1 knock-down exosomes. In contrast, exosome abundance of the transcripts for hsa-mir-16 and hsa-mir-92a, both of which were showed as tumor suppressor in breast cancer cells, were reduced by cyclin D1 shRNA. The cyclin D1-mediated miRNA exosome content may contribute to tumor initiation and progression through heterotypic expansion of cancer stem cells. 1.Yu, Z., etal ., A cyclin D1/microRNA 17/20 regulatory feedback loop in control of breast cancer cell proliferation. J Cell Biol. 2008 Aug 11; 182(3): p. 509-17. 2.Yu., Z,., et. al. Cyclin D1 induction of Dicer governs microRNA processing and expression in breast cancer. Nat Commun 2013;4:2812.doi: 10.1038/ncomms3812. 3.Yu Z, et al. Cyclin D1- Mediated MicroRNA Expression Signature in Breast Cancer Subtype and Outcome. Theranostics, 2018 Mar 11,8:8, 2251-2263. 4.Lü J, et al. Cyclin D1 promotes secretion of pro-oncogenic immuno-miRNAs and piRNAs. Clin Sci (Lond). 2020 Mar 27. pii: CS20191318. doi: 10.1042/CS20191318. [Epub ahead of print]PMID:32219337 Citation Format: Xuanmao Jiao, Chongwen Xu, Lifeng Tian, Zhao Zhang, Anthony W Ashton, Zhiping Li, Richard G Pestell. Enrichment of pro-oncogenic immune miRNAs in exosomes by cyclin D1, promote cancer stem cell expansion [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-10-03.

Supplementary Figure 1 from Novel Role of Thromboxane Receptors β Isoform in Bladder Cancer Pathogenesis

These studies were undertaken to determine the potential role of thromboxane receptors (TP) in bladder cancer. The data reported herein show that expression of the TP-β receptor protein is increased in tissue obtained from patients with bladder cancer and associated with a significantly poorer prognosis (P < 0.005). Bladder cancer cell lines express the TP-β isoform, unlike immortalized nontransformed urothelial cells (SV-HUC) that express only the TP-α isoform. TP-β receptor expression, but not TP-α, promoted cell proliferation, migration, and invasion in vitro, and also resulted in malignant transformation of SV-HUC cells in vivo. Agonist-mediated phosphorylation of extracellular signal-regulated kinase and FAK was dependent on the expression of TP-β. Furthermore, TP-β mediated multiple biological effects by signaling through either G-protein α subunit 12 or β-arrestin 2. Treatment of mice with the TP receptor antagonist GR32191, alone or in combination with cisplatin, significantly delayed tumor onset and prolonged survival of mice transplanted with TCC-SUP bladder cancer cells compared with vehicle or cisplatin alone. These results support the model that the TP-β receptor isoform plays a unique role in bladder cancer progression and its expression may have predictive value and provide a novel therapeutic target. [Cancer Res 2008;68(11):4097–104]

Supplementary Figure 2 from Novel Role of Thromboxane Receptors β Isoform in Bladder Cancer Pathogenesis

Prostate cancer (PCa), the second leading cause of death in American men, includes distinct genetic subtypes with distinct therapeutic vulnerabilities. The DACH1 gene encodes a winged helix/Forkhead DNA-binding protein that competes for binding to FOXM1 sites. Herein, DACH1 gene deletion within the 13q21.31-q21.33 region occurs in up to 18% of human PCa and was associated with increased AR activity and poor prognosis. In prostate OncoMice, prostate-specific deletion of the Dach1 gene enhanced prostatic intraepithelial neoplasia (PIN), and was associated with increased TGFb activity and DNA damage. Reduced Dach1 increased DNA damage in response to genotoxic stresses. DACH1 was recruited to sites of DNA damage, augmenting recruitment of Ku70/Ku80. Reduced Dach1 expression was associated with increased homology directed repair and resistance to PARP inhibitors and TGFb kinase inhibitors. Reduced Dach1 expression may define a subclass of PCa that warrants specific therapies.

Lysine acetylation is a common reversible post-translational modification of proteins that plays a key role in regulating gene expression. Nuclear receptors (NRs) include ligand-inducible transcription factors and orphan receptors for which the ligand is undetermined, which together regulate the expression of genes involved in development, metabolism, homeostasis, reproduction and human diseases including cancer. Since the original finding that the ERα, AR and HNF4 are acetylated, we now understand that the vast majority of NRs are acetylated and that this modification has profound effects on NR function. Acetylation sites are often conserved and involve both ordered and disordered regions of NRs. The acetylated residues function as part of an intramolecular signalling platform intersecting phosphorylation, methylation and other modifications. Acetylation of NR has been shown to impact recruitment into chromatin, co-repressor and coactivator complex formation, sensitivity and specificity of regulation by ligand and ligand antagonists, DNA binding, subcellular distribution and transcriptional activity. A growing body of evidence in mice indicates a vital role for NR acetylation in metabolism. Additionally, mutations of the NR acetylation site occur in human disease. This review focuses on the role of NR acetylation in coordinating signalling in normal physiology and disease.

The essential G1-cyclin, CCND1, is a collaborative nuclear oncogene that is frequently overexpressed in cancer. D-type cyclins bind and activate CDK4 and CDK6 thereby contributing to G1–S cell-cycle progression. In addition to the nucleus, herein cyclin D1 was also located in the cytoplasmic membrane. In contrast with the nuclear-localized form of cyclin D1 (cyclin D1NL), the cytoplasmic membrane-localized form of cyclin D1 (cyclin D1MEM) induced transwell migration and the velocity of cellular migration. The cyclin D1MEM was sufficient to induce G1–S cell-cycle progression, cellular proliferation, and colony formation. The cyclin D1MEM was sufficient to induce phosphorylation of the serine threonine kinase Akt (Ser473) and augmented extranuclear localized 17β-estradiol dendrimer conjugate (EDC)-mediated phosphorylation of Akt (Ser473). These studies suggest distinct subcellular compartments of cell cycle proteins may convey distinct functions.

Background: Prostate cancer (PCa), the second leading cause of death in American men, includes distinct genetic subtypes with distinct therapeutic vulnerabilities. The DACH1 gene encodes a winged helix/Forkhead DNA-binding protein that competes for binding to FOXM1 sites. Methods: Analysis of DACH1 gene deletion and gene expression was conducted from public data bases and human prostate cancer samples. Transgenic mice were generated in which the Dach1 gene was deleted in the prostate of prostate Oncomice. Cells derived from Dach1 gene deletion mice and human prostate cancer cell lines with Dach1 knockdown were analyzed for DNA damage repair responses. Results: DACH1 gene deletion within the 13q21.31-q21.33 region, occurred in up to 18% of human PCa, and was associated with increased AR activity, and poor prognosis. DACH1 homozygous deletions more frequent in the metastatic site than in the primary tumors (Mich: 10% vs. 18%, N=59; FHCRC: 4% vs.11%, N= 54, SU2C: not profiled vs. 3.3, N=150). The prevalence of DACH1 heterozygous deletions was higher in the metastatic lesions than in primary tumors within a given cohort for three of six cohorts (Mich: 27.3% vs. 36%, N=59; FHCRC: 15% vs. 59%, N=54; SU2C: 0% vs. 26%, N=150, respectively). The patients with homozygous DACH1 deletions had reduced overall survival (medians of 84 vs. 120 months, N=667, log rank test P=9.3x10-3). Low DACH1 gene expression (expressed as a z-score with a z-score threshold of -1.25) was significantly correlated with earlier biochemical recurrence (BCR, log rank p value = 4.7x10-4, n=79). In prostate OncoMice, prostate-specific deletion of the Dach1 gene enhanced prostatic intraepithelial neoplasia (PIN) and was associated with increased DNA damage. Reduced Dach1 increased DNA damage in responses to genotoxic stresses. DACH1 was recruited to sites of DNA damage, augmenting recruitment of Ku70/Ku80. Reduced Dach1 expression was associated with resistance to TGFβ kinase and PARP inhibitors. Conclusions: Reduced Dach1 expression may define a subclass of PCa that warrants specific therapies. Citation Format: Zhiping Li, Xuanmao Jiao, Gordon Robertson, Gabriele Di Sante, Anthony W. Ashton, Agnese DiRocco, Min Wang, Jun Zhao, Sankar Addya, Chenguang Wang, Peter A. McCue, Andrew P. South, Carlos Cordon-Cardo, Runzhi Liu, Kishan Patel, Rasha Hamid, Jorim Parmar, James B. DuHadaway, Nikolaus Schultz, Andrew Kossenkov, Lai Yee Phoon, Hao Chen, Li Lan, Yunguang Sun, Kenneth A. Iczkowski, Hallgeir Rui, Richard G. Pestell. The DACH1 gene is frequently deleted in prostate cancer, restrains prostatic intraepithelial neoplasia, augments DNA damage repair and predicts therapy responses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2598.

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are the leading causes of maternal and fetal morbidity/mortality. The central deficit in both conditions is impaired placentation due to poor trophoblast invasion, resulting in a hypoxic milieu in which oxidative stress contributes to the pathology. We examine the factors driving the hypoxic response in severely preterm PE (n = 19) and IUGR (n = 16) placentae compared to the spontaneous preterm (SPT) controls (n = 13) using immunoblotting, RT-PCR, immunohistochemistry, proximity ligation assays, and Co-IP. Both hypoxia-inducible factor (HIF)-1α and HIF-2α are increased at the protein level and functional in pathological placentae, as target genes prolyl hydroxylase domain (PHD)2, PHD3, and soluble fms-like tyrosine kinase-1 (sFlt-1) are increased. Accumulation of HIF-α-subunits occurs in the presence of accessory molecules required for their degradation (PHD1, PHD2, and PHD3 and the E3 ligase von Hippel–Lindau (VHL)), which were equally expressed or elevated in the placental lysates of PE and IUGR. However, complex formation between VHL and HIF-α-subunits is defective. This is associated with enhanced VHL/DJ1 complex formation in both PE and IUGR. In conclusion, we establish a significant mechanism driving the maladaptive responses to hypoxia in the placentae from severe PE and IUGR, which is central to the pathogenesis of both diseases.

Patients with diabetes with coronary microvascular disease (CMD) exhibit higher cardiac mortality than patients without CMD. However, the molecular mechanism by which diabetes promotes CMD is poorly understood. RNA-binding protein human antigen R (HuR) is a key regulator of mRNA stability and translation; therefore, we investigated the role of HuR in the development of CMD in mice with type 2 diabetes. Diabetic mice exhibited decreases in coronary flow velocity reserve (CFVR; a determinant of coronary microvascular function) and capillary density in the left ventricle. HuR levels in cardiac endothelial cells (CECs) were significantly lower in diabetic mice and patients with diabetes than the controls. Endothelial-specific HuR-KO mice also displayed significant reductions in CFVR and capillary density. By examining mRNA levels of 92 genes associated with endothelial function, we found that HuR, Cx40, and Nox4 levels were decreased in CECs from diabetic and HuR-KO mice compared with control mice. Cx40 expression and HuR binding to Cx40 mRNA were downregulated in CECs from diabetic mice. Cx40-KO mice exhibited decreased CFVR and capillary density, whereas endothelium-specific Cx40 overexpression increased capillary density and improved CFVR in diabetic mice. These data suggest that decreased HuR contributes to the development of CMD in diabetes through downregulation of gap junction protein Cx40 in CECs.

Cyclin-dependent kinases (CDKs) govern cell-cycle checkpoint transitions necessary for cancer cell proliferation. Recent developments have illustrated nuanced important differences between mono CDK inhibitor (CDKI) treatment and the combination therapies of breast cancers. The CDKIs that are currently FDA-approved for breast cancer therapy are oral agents that selectively inhibit CDK4 and CDK6, include palbociclib (Ibrance), ribociclib (Kisqali), and abemaciclib (Verzenio). CDKI therapy is effective in hormone receptor positive (HR+), and human epidermal growth factor receptor two negative (HER2−) advanced breast cancers (ABC) malignancies, but remains susceptible due to estrogen and progesterone receptor overexpression. Adding a CDK4/6I to endocrine therapy increases efficacy and delays disease progression. Given the side effects of CDKI, identifying potential new treatments to enhance CDKI effectiveness is essential. Recent long-term studies with Palbociclib, including the PALLAS and PENELOPE B, which failed to meet their primary endpoints of influencing progression-free survival, suggest a deeper mechanistic understanding of cyclin/CDK functions is required. The impact of CDKI on the anti-tumor immune response represents an area of great promise. CDKI therapy resistance that arises provides the opportunity for specific types of new therapies currently in clinical trials.

The extracellular matrix (ECM) is the tissue microenvironment that regulates the characteristics of stromal and systemic cells to control processes such as inflammation and angiogenesis. Despite ongoing anti‐inflammatory treatment, low levels of inflammation exist in the airways in asthma, which alters ECM deposition by airway smooth muscle (ASM) cells. The altered ECM causes aberrant behaviour of cells, such as endothelial cells, in the airway tissue. We therefore sought to characterize the composition and angiogenic potential of the ECM deposited by asthmatic and non‐asthmatic ASM. After 72 hours under non‐stimulated conditions, the ECM deposited by primary human asthmatic ASM cells was equal in total protein, collagen I, III and fibronectin content to that from non‐asthmatic ASM cells. Further, the matrices of non‐asthmatic and asthmatic ASM cells were equivalent in regulating the growth, activity, attachment and migration of primary human umbilical vein endothelial cells (HUVECs). Under basal conditions, asthmatic and non‐asthmatic ASM cells intrinsically deposit an ECM of equivalent composition and angiogenic potential. Previous findings indicate that dysregulation of the airway ECM is driven even by low levels of inflammatory provocation. This study suggests the need for more effective anti‐inflammatory therapies in asthma to maintain the airway ECM and regulate ECM‐mediated aberrant angiogenesis.

Simple Summary HER2, which is associated with clinically aggressive disease, is overexpressed in 15–20% of breast cancers (BC). Peroxisome proliferator-activated receptor γ (PPARγ), is expressed in a variety of malignancies. The aim of our study was to determine the function of endogenous Pparγ1 in the onset and progression of mammary tumors induced by ErbB2 in mice. Genetic deletion of Pparγ1 slowed the rate of tumor progression and death from ErbB2-induced mammary tumors. The deletion of Pparγ1 correlated with reduced pro-tumorigenic inflammation. We conclude ErbB2 collaborates with endogenous Pparγ1 in the onset and progression of mammary tumorigenesis. Abstract HER2, which is associated with clinically aggressive disease, is overexpressed in 15–20% of breast cancers (BC). The host immune system participates in the therapeutic response of HER2+ breast cancer. Identifying genetic programs that participate in ErbB2-induced tumors may provide the rational basis for co-extinction therapeutic approaches. Peroxisome proliferator-activated receptor γ (PPARγ), which is expressed in a variety of malignancies, governs biological functions through transcriptional programs. Herein, genetic deletion of endogenous Pparγ1 restrained mammary tumor progression, lipogenesis, and induced local mammary tumor macrophage infiltration, without affecting other tissue hematopoietic stem cell pools. Endogenous Pparγ1 induced expression of both an EphA2-Amphiregulin and an inflammatory INFγ and Cxcl5 signaling module, that was recapitulated in human breast cancer. Pparγ1 bound directly to growth promoting and proinflammatory target genes in the context of chromatin. We conclude Pparγ1 promotes ErbB2-induced tumor growth and inflammation and represents a relevant target for therapeutic coextinction. Herein, endogenous Pparγ1 promoted ErbB2-mediated mammary tumor onset and progression. PPARγ1 increased expression of an EGF-EphA2 receptor tyrosine kinase module and a cytokine/chemokine 1 transcriptional module. The induction of a pro-tumorigenic inflammatory state by Pparγ1 may provide the rationale for complementary coextinction programs in ErbB2 tumors.

The mechanisms governing therapeutic resistance of the most aggressive and lethal primary brain tumor in adults, glioblastoma, have increasingly focused on tumor stem cells. These cells, protected by the periarteriolar hypoxic GSC niche, contribute to the poor efficacy of standard of care treatment of glioblastoma. Integrated proteogenomic and metabolomic analyses of glioblastoma tissues and single cells have revealed insights into the complex heterogeneity of glioblastoma and stromal cells, comprising its tumor microenvironment (TME). An additional factor, which isdriving poor therapy response is the distinct genetic drivers in each patient’s tumor, providing the rationale for a more individualized or personalized approach to treatment. We recently reported that the G protein-coupled receptor CCR5, which contributes to stem cell expansion in other cancers, is overexpressed in glioblastoma cells. Overexpression of the CCR5 ligand CCL5 (RANTES) in glioblastoma completes a potential autocrine activation loop to promote tumor proliferation and invasion. CCL5 was not expressed in glioblastoma stem cells, suggesting a need for paracrine activation of CCR5 signaling by the stromal cells. TME-associated immune cells, such as resident microglia, infiltrating macrophages, T cells, and mesenchymal stem cells, possibly release CCR5 ligands, providing heterologous signaling between stromal and glioblastoma stem cells. Herein, we review current therapies for glioblastoma, the role of CCR5 in other cancers, and the potential role for CCR5 inhibitors in the treatment of glioblastoma.

Intrauterine Growth Restriction (IUGR) is a leading cause of perinatal death with no effective cure, affecting 5–10% pregnancies globally. Suppressed pro-inflammatory Th1/Th17 immunity is necessary for pregnancy success. However, in IUGR, the inflammatory response is enhanced and there is a limited understanding of the mechanisms that lead to this abnormality. Regulation of maternal T-cells during pregnancy is driven by Nuclear Factor Kappa B p65 (NF-κB p65), and we have previously shown that p65 degradation in maternal T-cells is induced by Fas activation. Placental exosomes expressing Fas ligand (FasL) have an immunomodulatory function during pregnancy. The aim of this study is to investigate the mechanism and source of NF-κB regulation required for successful pregnancy, and whether this is abrogated in IUGR. Using flow cytometry, we demonstrate that p65+ Th1/Th17 cells are reduced during normal pregnancy, but not during IUGR, and this phenotype is enforced when non-pregnant T-cells are cultured with normal maternal plasma. We also show that isolated exosomes from IUGR plasma have decreased FasL expression and are reduced in number compared to exosomes from normal pregnancies. In this study, we highlight a potential role for FasL+ exosomes to regulate NF-κB p65 in T-cells during pregnancy, and provide the first evidence that decreased exosome production may contribute to the dysregulation of p65 and inflammation underlying IUGR pathogenesis.

Background Diabetic patients with coronary microvascular disease (CMD) exhibit higher cardiac mortality than patients without CMD. However, the molecular mechanism by which diabetes promotes CMD is poorly understood. RNA-binding protein HuR is a key regulator of mRNA stability and translation of many genes, and there is growing evidence showing the potential role of HuR in cardiovascular disease. In this study, we investigated the role of HuR and its target genes in the development of CMD in type 2 diabetic mice. Methods Type 2 diabetes was induced in male mice by a high-fat diet combined with a single injection of low-dose streptozotocin. We assessed coronary flow velocity reserve (CFVR, a determinant of coronary microvascular function) in vivo and isolated cardiac endothelial cells (CECs) from those mice for in vitro experiment. Coronary endothelial function was evaluated in the 3rd order of coronary arteries using a wire myograph. Human CECs from 4 control subjects and 4 diabetic patients were purchased from the company. Results Diabetic mice exhibited decreases in CFVR and capillary density in the left ventricle (LV). HuR protein levels in CECs were significantly lower in diabetic mice and diabetic patients than in the controls. Endothelial-specific HuR-KO mice also displayed significant reductions in CFVR and capillary density. By examining mRNA levels of 92 genes associated with endothelial function, we found that HuR, Cx40, and Nox4 levels were decreased in CECs from diabetic and HuR-KO mice in comparison to control mice. Cx40 protein level and HuR binding to Cx40 mRNA were downregulated in CECs from diabetic mice, and Cx40-KO mice exhibited decreased CFVR, attenuated endothelium-dependent relaxation, and reduced capillary density in the LV. Furthermore, endothelium-specific Cx40 overexpression ameliorated endothelial functions by augmenting endothelium-dependent relaxation and increasing capillary density in the LV, and resulted in the improvement of CFVR in diabetic mice. Conclusions These data suggest that decreased HuR, a specific mRNA binding protein that downregulates gap junction protein Cx40 in CECs, plays an important role in the development of coronary microvascular disease in diabetes. Restoration of Cx40 expression and function is potentially a novel therapeutic strategy for diabetic cardiovascular complications.

Background Abnormal endothelial function in the lungs is implicated in the development of pulmonary hypertension; however, there is little information about the difference of endothelial function between small distal pulmonary artery (PA) and large proximal PA and their contribution to the development of pulmonary hypertension. Herein, we investigate endothelium‐dependent relaxation in different orders of PAs and examine the molecular mechanisms by which chronic hypoxia attenuates endothelium‐dependent pulmonary vasodilation, leading to pulmonary hypertension. Methods and Results Endothelium‐dependent relaxation in large proximal PAs (second order) was primarily caused by releasing NO from the endothelium, whereas endothelium‐dependent hyperpolarization (EDH)–mediated vasodilation was prominent in small distal PAs (fourth–fifth order). Chronic hypoxia abolished EDH‐mediated relaxation in small distal PAs without affecting smooth muscle–dependent relaxation. RNA‐sequencing data revealed that, among genes related to EDH, the levels of Cx37 , Cx40 , Cx43 , and IK were altered in mouse pulmonary endothelial cells isolated from chronically hypoxic mice in comparison to mouse pulmonary endothelial cells from normoxic control mice. The protein levels were significantly lower for connexin 40 (Cx40) and higher for connexin 37 in mouse pulmonary endothelial cells from hypoxic mice than normoxic mice. Cx40 knockout mice exhibited significant attenuation of EDH‐mediated relaxation and marked increase in right ventricular systolic pressure. Interestingly, chronic hypoxia led to a further increase in right ventricular systolic pressure in Cx40 knockout mice without altering EDH‐mediated relaxation. Furthermore, overexpression of Cx40 significantly decreased right ventricular systolic pressure in chronically hypoxic mice. Conclusions These data suggest that chronic hypoxia‐induced downregulation of endothelial Cx40 results in impaired EDH‐mediated relaxation in small distal PAs and contributes to the development of pulmonary hypertension.

© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine. Neovascularization, increased basal membrane thickness and increased airway smooth muscle (ASM) bulk are hallmarks of airway remodelling in asthma. In this study, we examined connective tissue growth factor (CTGF) dysregulation in human lung tissue and animal models of allergic airway disease. Immunohistochemistry revealed that ASM cells from patients with severe asthma (A) exhibited high expression of CTGF, compared to mild and non-asthmatic (NA) tissues. This finding was replicated in a sheep model of allergic airways disease. In vitro, transforming growth factor (TGF)-β increased CTGF expression both in NA- and A-ASM cells but the expression was higher in A-ASM at both the mRNA and protein level as assessed by PCR and Western blot. Transfection of CTGF promoter-luciferase reporter constructs into NA- and A-ASM cells indicated that no region of the CTGF promoter (−1500 to +200 bp) displayed enhanced activity in the presence of TGF-β. However, in silico analysis of the CTGF promoter suggested that distant transcription factor binding sites may influence CTGF promoter activation by TGF-β in ASM cells. The discord between promoter activity and mRNA expression was also explained, in part, by differential post-transcriptional regulation in A-ASM cells due to enhanced mRNA stability for CTGF. In patients, higher CTGF gene expression in bronchial biopsies was correlated with increased basement membrane thickness indicating that the enhanced CTGF expression in A-ASM may contribute to airway remodelling in asthma.

Summary Previous attempts in cardiac bioengineering have failed to provide tissues for cardiac regeneration. Recent advances in 3-dimensional bioprinting technology using prevascularized myocardial microtissues as ‘bioink’ have provided a promising way forward. This review guides the reader to understand why myocardial tissue engineering is difficult to achieve and how revascularization and contractile function could be restored in 3-dimensional bioprinted heart tissue using patient-derived stem cells.

miRNAs are a class of endogenous noncoding small RNAs that participate in diverse biological processes through base-pairing to the complementary sequence in 3' untranslated region (3' UTR) of mRNA Specific miRNA have been associated with the initiation, progression and therapy resistance and regulate immunological processes including the activation and ageing of innate and adaptive immune cells. Immuno-miRs, including. miR-21 and miR-93, regulate immune function in the tumor microenvironment by binding to the 3′-UTR region of target mRNAs, or by binding to- and activating Toll-Like Receptor 8 (TLR8) in surrounding cells of the immune system. The cyclin D1 (CCND1) gene, which encodes the regulatory subunit of a holoenzyme that phosphorylates and inactivates the Rb protein, is overexpressed in up to 50% of human breast cancers. Cyclin D1, governs the expression, processing, the secretion and the relative proportion of secreted non-coding RNA subtypes (miRNA, rRNA, tRNA, CDBox, scRNA, HAcaBox. scaRNA, piRNA) in human breast cancer and the secretion of piRNA. Exosomes, which consist of a lipid bilayer membrane surrounding a small cytosol, contain constituents of their cell of origin, including mRNA and miRNA. Exosomes in the tumor microenvironment, participate in therapy resistance, cancer metastasis and the metastatic niche. Herein, knock down of cyclin D1 in MCF-7 cells with tet-inducible cyclin D1 shRNA decreased MCF-7 cell proliferation and mammosphere formation. Exosomes isolated from wild-type and cyclin D1 knock-down MCF-7 cell culture media, showed that exosomes from cyclin D1 knock down cells dramatically decreased proliferation of both wild-type and cyclin D1 knock-down cells, whereas the wild-type exosomes partially reversed the cyclin D1 knock down effects. Cyclin D1 knock-down exosomes decreased mammosphere formation of wild-type MCF-7 cells and wild-type exosomes increased mammosphere formation of cyclin D1 knock-down cells. miRNA profiles within the exosomes, showed that cyclin D1 regulated the abundance of miRNA within exosomes. The pattern of miRNA within exosomes regulated by cyclin D1 were enriched for miRNA governing mesenchymal epithelial transition and the induction of stem cell function. The most enriched miRNA in cyclin D1 wild-type exosomes was hsa-mir-21 which was recognized tumor promoting function, whereas the most enriched miRNAs in cyclin D1 knock-down exosomes were has-mir-16 and has-mir-92a, both of which were shown as tumor suppressor in breast cancer cells. The immune-miR miR-21 represented >85% of the cyclin D1-induced exosome miRNA transcripts, The cyclin D1-mediated miRNA exosome content may contribute to tumor initiation and progression through heterotypic expansion of cancer stem cells. Citation Format: Xuanmao Jiao, Chongwen Xu, Lifeng Tian, Zhao Zhang, Anthony W. Ashton, Zhiping Li, Richard G. Pestell. Cyclin D1 mediated exosomes are enriched for pro-oncogenic miRNAs and promote cancer stem cell expansion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2356.

Cardiac toxicity from chemotherapy, which contributes substantially to morbidity and mortality in cancer survivors is dose-dependent, but sensitivity can vary greatly between patients. Doxorubicin (DOX) reduces ventricular ejection fraction to 1.5 million women develop breast cancer annually, it is estimated that >50,000 women/year will develop severe cardiotoxicity. With cancer survivors estimated at 19 million in the USA by 2025, DOX-induced cardiotoxicity is considered part of the “cardio-oncology epidemic”. Two cellular activities: DNA damage, causing double-strand breaks (DSBs) following poisoning of topoisomerase II (Topo II), and chromatin damage, mediated through histone eviction, are required for cardiotoxicity. The only FDA approved preventive, dexrazoxane reduces the anti-cancer efficacy of the DOX-based chemotherapeutic agents has the concerning side effects of myelotoxicity and a possible increased prevalence of secondary malignancies. We previously showed that the G-protein coupled receptor CCR5 is expressed on both immune and epithelial cells of ~50% of human breast cancers (BCa), thereby inducing cancer “stemness”, cell survival and DNA repair and a pro-metastatic phenotype. Moreover, CCR5 expression is enhanced in DOX-resistant BCa cells and CCR5 inhibitors (CCR5i) enhance DOX-induced cell death of BCa cells. Whilst expression of CCR5 and its ligands (CCL3 and CCL5) were induced by DOX-treatment in cardiac myocytes in both a murine model of DOX-cardiac toxicity and in the hearts of patients undergoing cardiac transplantation for DOX-induced cardiomyopathy. Unlike in BCa cells (where the enhanced CCR5 expression is transcriptionaly regulated) the increased expression in the myocardium occurs in the absence of altered mRNA levels suggesting epigenetic control over CCR5 expression during DOX-induced cardiotoxicity. In the myocardium CCR5 signaling promotes cardiac remodeling and heart failure, opposite that in BCa where CCR5 signaling promotes survival. Not surprisingly, CCR5i protected human iPSC-derived cardiomyocytes and isolated canine cardiomyocytes from DOX-induced cell death using nuclear fragmentation (hypodiploid peak) and mitochondrial function (MitoGlo reagent) as endpoints. Further, in a murine model of DOX cardiotoxicity (3 mg/kgx8 doses over 2 weeks) CCR5i substantially reduced (>90%) DOX-induced cardiac dysfunction and mortality in mice. CCR5 inhibitors (CCR5i) are “dual function” compounds that provide both cardiac protection and enhanced breast cancer cell killing in the presence of DNA damaging chemotherapy agents. Our studies may have a broad impact by identifying a novel approach to both enhancing therapeutic efficacy and providing cardioprotection from DNA damaging agents that are widely used in cancer treatment. Citation Format: Anthony W. Ashton, Xuanmao Jiao, Zhiping Li, Joseph C. Wu, Cristobal dos Remedios, Sean Lal, Richard Kitsis, Richard G. Pestell. CCR5 inhibitors enhance doxorubicin-induced breast cancer cell killing while reducing cardiotoxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1334.

Human coronavirus, hCoV-19 (SARS-CoV-2) is associated with pneumonia, severe systemic disease and, in fatal cases, a high prevalence of cardiac dysfunction. Cellular entry requires a cell-surface receptor, angiotensin-converting enzyme 2 (ACE2), and activation of the spike protein by host proteases, including TMPRSS2 and cathepsins. Cardiac toxicity is a serious cause of morbidity and mortality from SARS-CoV-2 with chronic sequelae reducing cardiac function in many survivors. We determined mRNA expression for genes related to SARS-Cov-2 infection in iPSC-derived cardiac myocytes treated with the widely used chemotherapeutic, Doxorubicin (DOX). DOX induced expression of TMPSS2, but not Ace2 or Furin, 4- to 5-fold. Further, DOX treatment enhanced expression of cathepsins A, B and F between 1.2-1.5 fold. Overall these changes promote an environment of enhanced SARS-CoV-2 susceptibility in the myocardium placing cancer patients on DOX therapy at increased risk of cardiac damage. To further characterize the effects of SARS-CoV-2 on the myocardium we examined the local spatial gene expression response in human post-mortem cardiac samples. A genome wide (1,864 genes) and matching proteome analysis on SARS-CoV-2 infected myocardium was conducted using Digital spatial profiling (DSP) (NanoString GeoMxTM). RNAscopeTM, a sensitive form of fluorescence in situ hybridization (FISH), identified SARS-CoV-2 spike RNA in cells enriched for ACE2 and TMPRSS2. Immunohistochemistry on serial sections identified the SARS-CoV-2 spike protein in both myocyte (desmin+) and monocyte (CD45+) populations suggesting multiple targets for viral infection in the myocardium. SCANscopeTM was used to determine the effects of SARS-CoV-2 on cardiac gene. Probes directed to the spike protein were used to identify regions of interest (ROI) for SARS-CoV-2-infection. Unsupervised principal component analysis (PCA) of the differentially expressed gene transcripts separated gene expression of SARS-CoV-2 ROI from control ROI areas in the same patient and was distinct from the PCA of normal myocardium control ROI. PCA of the SARS-CoV-2-associated gene expression of the ROI from male vs. female myocardium identified distinct gender-related gene expression patterns. Further, PCA based on SARS-Cov-2 spike RNA abundance correlated with induction of innate and acquired immunity signaling in the myocardial cells. Moreover, gene ontology (Reactome) analysis of SARS-CoV-2 infected regions of the myocardium displayed characteristic signatures indicating enhanced apoptosis and autophagy, chromatin remodeling and reduced DNA repair, and reduced oxidoreductase activity in regions of SARS-CoV-2 infection compared to uninfected myocardium. These data probe the underlying molecular mechanisms that enhance the risk of death from SARS-CoV-2 for cancer patients and the cardiac remodeling that results in death for many patients with COVID-19. Citation Format: Anthony W. Ashton, Liang Zhang, Yan Liang, Prajan Divakar, Carolos Cordon-Cardo, Richard G. Pestell. SARS-CoV-2 infection of the human heart governs intracardiac innate immune response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 705.

Molecular analysis of all cancer types in the cancer genome atlas (TCGA) demonstrated that multiple pathways may be disrupted within a given tumor including PCa. Prostate cancer (PCa), the second leading cause of death in American men, includes distinct genetic subtypes with distinct therapeutic vulnerabilities. Substratification of PCa into genetic subtypes, forms the basis of rational therapy for PCa. Known genetic drivers to PCa include deletions of target genes (PTEN and NKX3.1 deletions), rearrangements/fusions of multiple genes (including TMPRSS2 and the oncogenic ETS transcription factor, ERG) and genetic predisposing factors (including germline DNA-repair gene mutations). An increasingly common finding in PCa are defects in DNA repair. The Drosophila Dac gene was initially cloned as dominant inhibitor of Elipse. The human homologue, DACH1, encodes a winged helix/Forkhead DNA-binding protein that binds in chromatin to FOXM1 sites. Herein, reduced expression of DACH1 is shown in PCa, correlating with DACH1 promoter methylation. Homozygous deletion of DACH1 occurred in up to 18% of human PCa, associated with increased AR activity, increased somatic copy-number alteration and poor prognosis. DACH1 increased DNA repair, as shown in comet assays, enhancing nonhomologous end joining (NHEJ) while reducing homology directed repair (HDR) in DNA repair reporter assays. Laser wounding showed DACH1 was recruited to sites of DNA damage, augmenting the recruitment of Ku70/Ku80. In Dach1 deletion cells reduced expression of Dach1 was associated with resistance to inhibitors of Poly-(ADP)-ribose polymerase (PARP) and enhanced sensitivity to inhibitors of WEE1 kinase and DNA-PK. The abundance of DACH1 in prostate cancer may define a subclass of prostate cancer warranting selective therapies. Citation Format: Zhiping Li, Xuanmao Jiao, A. Gordon Robertson, Anthony W. Ashton, Andrew Kossenkov, Hao Chen, Lai Yee Phoon, Li Lan, Richard G. Pestell. The Forkhead-like protein Dach1 governs sensitivity to WEE1 kinase and PARP inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2500.

Encouraging changes in the steroid hormone receptor field from initially questioning the role of non-genomic actions of steroid hormones to acceptance of the concept that the acute, membrane-centric actions are linked and/or regulate the nuclear actions. The focus of this chapter is how the non-genomic effects are linked to the longer lasting, genomic actions of aldosterone. By non-genomic we refer to the rapid actions that occur within minutes do not require transcription or translation and occur in both classical MR target organs (kidney and colon) and non-epithelial tissues (blood vessels, heart, and adipose). The mechanism of rapid non-genomic actions of aldosterone varies between tissues. As a result, this chapter is viewed through the lens of how the non-genomic and genomic actions of aldosterone are linked in cardiovascular disease. Specifically, regulation of sodium flux in the myocardium has an important role in pathogenesis of cardiac arrhythmia. Since there are now recognized gender differences in cardiovascular disease, we also include preliminary studies to investigate the interaction of sex steroid hormones with the ligand binding pocket of the mineralocorticoid receptor. Overall, we aim to showcase how the non-genomic effects of aldosterone potentially modulate the genomic effects and represent additional targets for intervention.

Encouraging changes in the steroid hormone receptor field from initially questioning the role of non-genomic actions of steroid hormones to acceptance of the concept that the acute, membrane-centric actions are linked and/or regulate the nuclear actions. The focus of this chapter is how the non-genomic effects are linked to the longer lasting, genomic actions of aldosterone. By non-genomic we refer to the rapid actions that occur within minutes do not require transcription or translation and occur in both classical MR target organs (kidney and colon) and non-epithelial tissues (blood vessels, heart, and adipose). The mechanism of rapid non-genomic actions of aldosterone varies between tissues. As a result, this chapter is viewed through the lens of how the non-genomic and genomic actions of aldosterone are linked in cardiovascular disease. Specifically, regulation of sodium flux in the myocardium has an important role in pathogenesis of cardiac arrhythmia. Since there are now recognized gender differences in cardiovascular disease, we also include preliminary studies to investigate the interaction of sex steroid hormones with the ligand binding pocket of the mineralocorticoid receptor. Overall, we aim to showcase how the non-genomic effects of aldosterone potentially modulate the genomic effects and represent additional targets for intervention.

Trypanosoma cruzi is a protozoan parasite that causes Chagas disease (CD). CD is a persistent, lifelong infection affecting many organs, most notably the heart, where it may result in acute myocarditis and chronic cardiomyopathy. The pathological features include myocardial inflammation and fibrosis. In the Brazil strain-infected CD-1 mouse, which recapitulates many of the features of human infection, we found increased plasma levels of resolvin D1 (RvD1), a specialized proresolving mediator of inflammation, during both the acute and chronic phases of infection (>100 days postinfection) as determined by enzyme-linked immunosorbent assay (ELISA). Additionally, ELISA on lysates of trypomastigotes of both strains Tulahuen and Brazil revealed elevated levels of RvD1 compared with lysates of cultured epimastigotes of T. cruzi , tachyzoites of Toxoplasma gondii , trypomastigotes of Trypanosoma brucei , cultured L 6 E 9 myoblasts, and culture medium containing no cells. Lysates of T. cruzi -infected myoblasts also displayed increased levels of RvD1. Lipid mediator metabolomics confirmed that the trypomastigotes of T. cruzi produced RvD1, RvD5, and RvE2, which have been demonstrated to modulate the host response to bacterial infections. Plasma RvD1 levels may be both host and parasite derived. Since T. cruzi synthesizes specialized proresolving mediators of inflammation, as well as proinflammatory eicosanoids, such as thromboxane A 2 , one may speculate that by using these lipid mediators to modulate its microenvironment, the parasite is able to survive.

During activity, coordinated vasodilation of microcirculatory networks with upstream supply vessels increases blood flow to skeletal and cardiac muscles and reduces peripheral resistance. Endothelial dysfunction in humans attenuates activity-dependent vasodilation, resulting in exercise-induced hypertension in otherwise normotensive individuals. Underpinning activity-dependent hyperemia is an ascending vasodilation in which the endothelial gap junction protein, connexin (Cx)40, plays an essential role. Because exercise-induced hypertension is proposed as a forerunner to clinical hypertension, we hypothesized that endothelial disruption of Cx40 function in mice may create an animal model of this condition. To this end, we created mice in which a mutant Cx40T152A was expressed alongside wildtype Cx40 selectively in the endothelium. Expression of the Cx40T152A transgene in Xenopus oocytes and mouse coronary endothelial cells in vitro impaired both electric and chemical conductance and acted as a dominant-negative against wildtype Cx40, Cx43, and Cx45, but not Cx37. Endothelial expression of Cx40T152A in Cx40T152ATg mice attenuated ascending vasodilation, without effect on radial coupling through myoendothelial gap junctions. Using radiotelemetry, Cx40T152ATg mice showed an activity-dependent increase in blood pressure, which was significantly greater than in wildtype mice, but significantly less than in chronically hypertensive, Cx40knockout mice. The increase in heart rate with activity was also greater than in wildtype or Cx40knockout mice. We conclude that the endothelial Cx40T152A mutation attenuates activity-dependent vasodilation, producing a model of exercise-induced hypertension. These data highlight the importance of endothelial coupling through Cx40 in regulating blood pressure during activity.

Introduction Currently there are no clinical screening tests available to identify pregnancies at risk of developing preeclampsia (PET) and/or intrauterine growth restriction (IUGR), both of which are associated with abnormal placentation. Metabolic profiling is now a stable analytical platform used in many laboratories and has successfully been used to identify biomarkers associated with various pathological states. Methods We used nuclear magnetic resonance spectroscopy (NMR) to metabolically profile serum samples collected from 143 pregnant women at 26–41 weeks gestation with pregnancy outcomes of PET, IUGR, PET IUGR or small for gestational age (SGA) that were age-matched to normal pre/term pregnancies. Results Spectral analysis found no difference in the measured metabolites from normal term, pre-term and SGA samples, and of 25 identified metabolites, only glutamate was marginally different between groups. Of the identified metabolites, 3-methylhistidine, creatinine, acetyl groups and acetate, were determined to be independent predictors of PET and produced area under the curves (AUC) = 0.938 and 0.936 for the discovery and validation sets. Only 3-hydroxybutyrate was determined to be an independent predictor of IUGR, however the model had low predictive power (AUC = 0.623 and 0.581 for the discovery and validation sets). Conclusions A sub-panel of metabolites had strong predictive power for identifying PET samples in a validation dataset, however prediction of IUGR was more difficult using the identified metabolites. NMR based metabolomics can identify metabolites strongly associated with disease and has the potential to be useful in developing early clinical screening tests for at risk pregnancies.

Functional cell-based assays are useful for comparing the effect of a treatment, drug, or condition on cells in culture. Cell lines are a commonly used model to replicate a normal biological process or a pathological condition. Trophoblasts within the placenta are required to perform a variety of functions, which include proliferation, differentiation, migration, and invasion for efficient placentation to occur. These functions are impaired in trophoblasts from preeclamptic pregnancies, and therefore functional cell-based assays can be utilized to measure differences and dissect molecular regulatory pathways.

Functional cell-based assays are useful for comparing the effect of a treatment, drug, or condition on cells in culture. Cell lines are a commonly used model to replicate a normal biological process or a pathological condition. Trophoblasts within the placenta are required to perform a variety of functions, which include proliferation, differentiation, migration, and invasion for efficient placentation to occur. These functions are impaired in trophoblasts from preeclamptic pregnancies, and therefore functional cell-based assays can be utilized to measure differences and dissect molecular regulatory pathways.

Background: Low serum 25-hydroxyvitamin D [25(OH)D] concentrations during pregnancy have been associated with adverse pregnancy outcomes in a few studies but not in other studies. Objectives: We assessed the serum 25(OH)D concentration at 10– 14 wk pregnancy and its association with adverse pregnancy outcomes and examined the predictive accuracy. Design: In this nested case-control study, we measured serum 25(OH)D in 5109 women with singleton pregnancies who were attending first-trimester screening in New South Wales, Australia. Multivariate logistic regression was conducted to examine the association between low 25(OH)D concentrations and adverse pregnancy outcomes (small for gestational age, preterm birth, preeclampsia, gestational diabetes, miscarriage, and stillbirth). The predictive accuracy of models was assessed. Results: The median (IQR) 25(OH)D concentration for the total population was 56.4 nmol/L (43.3–69.8 nmol/L). Serum 25(OH)D concentrations showed significant variation by parity, smoking, weight, season of sampling, country of birth, and socioeconomic status. After adjustment for maternal and clinical risk factors, low 25(OH)D concentrations were not associated with most adverse pregnancy outcomes. The area under the receiver operating characteristic curve (AUC) and likelihood ratio for a composite of severe adverse pregnancy outcomes of 25(OH)D concentrations ,25 nmol/L were 0.51 and 1.44, respectively, and, for risk factors alone, were 0.64 and 2.87, respectively. The addition of 25(OH)D information to maternal and clinical risk factors did not improve the ability to predict severe adverse pregnancy outcomes (AUC: 0.64; likelihood ratio: 2.32; P = 0.39). Conclusion: Low 25(OH)D serum concentrations in the first trimester of pregnancy are not associated with adverse pregnancy outcomes and do not predict complications any better than routinely assessed clinical and maternal risk-factor information. Am J Clin Nutr doi: 10.3945/ajcn.113.065672.

Age-specific incidence of ischemic heart disease in men is higher than in women, although women die more frequently without previous symptoms; the molecular mechanism(s) are poorly understood. Most studies focus on protection by estrogen, with less attention on androgen receptor-mediated androgen actions. Our aim was to determine the role of androgens in the sex differences in cardiac damage during myocardial infarction. Mature age-matched male and female Sprague Dawley rats, intact or surgically gonadectomized (Gx), received testosterone (T) or 17β-estradiol (E2) via subdermal SILASTIC (Dow Corning Corp.) implants; a subset of male rats received dihydrotestosterone. After 21 days, animals were anesthetized, and hearts were excised and subjected to ex vivo regional ischemia-reperfusion (I-R). Hearts from intact males had larger infarcts than those from females following I-R; Gx produced the opposite effect, confirming a role for sex steroids. In Gx males, androgens (dihydrotestosterone, T) and E2 aggravated I-R-induced cardiac damage, whereas in Gx females, T had no effect and E2 reduced infarct area. Increased circulating T levels up-regulated androgen receptor and receptor for advanced glycation end products, which resulted in enhanced apoptosis aggravating cardiac damage in both males and females. In conclusion, our study demonstrates, for the first time, that sex steroids regulate autophagy during myocardial infarction and shows that a novel mechanism of action for androgens during I-R is down-regulation of antiapoptotic protein Bcl-xL (B cell lymphoma-extra large), a key controller for cross talk between autophagy and apoptosis, shifting the balance toward apoptosis and leading to aggravated cardiac damage.

Objective— To determine whether impairment of endothelial connexin40 (Cx40), an effect that can occur in hypertension and aging, contributes to the arterial dysfunction and stiffening in these conditions. Approach and Results— A new transgenic mouse strain, expressing a mutant Cx40, (Cx40T202S), specifically in the vascular endothelium, has been developed and characterized. This mutation produces nonfunctional hemichannels, whereas gap junctions containing the mutant are electrically, but not chemically, patent. Mesenteric resistance arteries from Cx40T202S mice showed increased sensitivity of the myogenic response to intraluminal pressure in vitro, compared with wild-type mice, whereas transgenic mice overexpressing native Cx40 (Cx40Tg) showed reduced sensitivity. In control and Cx40Tg mice, the sensitivity to pressure of myogenic constriction was modulated by both NO and endothelium-derived hyperpolarization; however, the endothelium-derived hyperpolarization component was absent in Cx40T202S arteries. Analysis of passive mechanical properties revealed that arterial stiffness was enhanced in vessels from Cx40T202S mice, but not in wild-type or Cx40Tg mice. Conclusions— Introduction of a mutant form of Cx40 in the endogenous endothelial Cx40 population prevents endothelium-derived hyperpolarization activation during myogenic constriction, enhancing sensitivity to intraluminal pressure and increasing arterial stiffness. We conclude that genetic polymorphisms in endothelial Cx40 can contribute to the pathogenesis of arterial disease.

Trypanosoma cruzi infection in humans and experimental animals causes Chagas disease which is often accompanied by myocarditis, cardiomyopathy, and vasculopathy. T. cruzi-derived thromboxane A2 (TXA2) modulates vasculopathy and other pathophysiological features of Chagasic cardiomyopathy. Here, we provide evidence that epimastigotes, trypomastigotes, and amastigotes of T. cruzi (Brazil and Tulahuen strains) express a biologically active prostanoid receptor (PR) that is responsive to TXA2 mimetics, e.g. IBOP. This putative receptor, TcPR, is mainly localized in the flagellar membrane of the parasites and shows a similar glycosylation pattern to that of bona fide thromboxane prostanoid (TP) receptors obtained from human platelets. Furthermore, TXA2-PR signal transduction activates T. cruzi-specific MAPK pathways. While mammalian TP is a G-protein coupled receptor (GPCR); T. cruzi genome sequencing has not demonstrated any confirmed GPCRs in these parasites. Based on this genome sequencing it is likely that TcPR is unique in these protists with no counterpart in mammals. TXA2 is a potent vasoconstrictor which contributes to the pathogenesis of Chagasic cardiovascular disease. It may, however, also control parasite differentiation and proliferation in the infected host allowing the infection to progress to a chronic state.

The extracellular matrix (ECM) creates the microenvironment of the tissue; an altered ECM in the asthmatic airway may be central in airway inflammation and remodelling. Tumstatin is a collagen IV‐derived matrikine reduced in the asthmatic airway wall that reverses airway inflammation and remodelling in small and large animal models of asthma. This study hypothesized that the mechanisms underlying the broad asthma‐resolving effects of tumstatin were due to autocrine remodelling of the ECM. Neutrophils and endothelial cells were seeded on decellularized ECM of non‐asthmatic (NA) or asthmatic (A) airway smooth muscle (ASM) cells previously exposed to tumstatin in the presence or absence of a broad matrix metalloproteinase inhibitor, Marimastat. Gene expression in NA and A ASM induced by tumstatin was assessed using RT‐PCR arrays. The presence of tumstatin during ECM deposition affected neutrophil and endothelial cell properties on both NA and A ASM‐derived matrices and this was only partly due to MMP activity. Gene expression patterns in response to tumstatin in NA and A ASM cells were different. Tumstatin may foster an anti‐inflammatory and anti‐angiogenic microenvironment by modifying ASM‐derived ECM. Further work is required to examine whether restoring tumstatin levels in the asthmatic airway represents a potential novel therapeutic approach.

Inbred strains of mice are powerful models for understanding human pregnancy complications. For example, the exclusive mating of CBA/J females to DBA/2J males increases fetal resorption to 20–35% with an associated decline in placentation and maintenance of maternal Th1 immunity. More recently other complications of pregnancy, IUGR and preeclampsia, have been reported in this model. The aim of this study was to qualify whether the CBA/CaH substrain female can substitute for CBA/J to evoke a phenotype of embryonic/fetal mortality and IUGR. (CBA/CaH × DBA/2J) F1 had significantly higher embryonic/fetal mortality mortality (p = 0.0063), smaller fetuses (p th percentile; 47% vs 10%) than (CBA/CaH × Balb/c) F1. Placentae from IUGR fetuses from all mating groups were significantly smaller (p 10th percentile). In addition, placentae of “normal-weight” (CBA/CaH × DBA/2J) F1 were significantly smaller (p

Intrauterine growth restriction (IUGR) is a pathology of pregnancy that results in failure of the fetus to reach its genetically determined growth potential. In developed nations the most common cause of IUGR is impaired placentation resulting from poor trophoblast function, which reduces blood flow to the fetoplacental unit, promotes hypoxia and enhances production of bioactive lipids (TXA2 and isoprostanes) which act through the thromboxane receptor (TP). TP activation has been implicated as a pathogenic factor in pregnancy complications, including IUGR; however, the role of TP isoforms during pregnancy is poorly defined. We have determined that expression of the human-specific isoform of TP (TPβ) is increased in placentae from IUGR pregnancies, compared to healthy pregnancies. Overexpression of TPα enhanced trophoblast proliferation and syncytialisation. Conversely, TPβ attenuated these functions and inhibited migration. Expression of the TPβ transgene in mice resulted in growth restricted pups and placentae with poor syncytialisation and diminished growth characteristics. Together our data indicate that expression of TPα mediates normal placentation; however, TPβ impairs placentation and promotes the development of IUGR and represents an underappreciated pathogenic factor in humans.

Multipotent P19CL6 cells differentiate into cardiac myocytes or neural lineages when stimulated with dimethyl sulfoxide (DMSO) or retinoic acid (RA), respectively. Expression of the transcription factor Tbx6 was found to increase during cardiac myocyte differentiation and to decrease during neural differentiation. Overexpression of Tbx6 was not sufficient to drive P19CL6 cells to a cardiac myocyte fate or to accelerate DMSO-induced differentiation. In contrast, knockdown of Tbx6 dramatically inhibited DMSO-induced differentiation of P19CL6 cells to cardiac myocytes, as evidenced by the loss of striated muscle-specific markers and spontaneous beating. Tbx6 knockdown was also accompanied by almost complete loss of Nkx2.5, a transcription factor involved in the specification of the cardiac myocyte lineage, indicating that Nkx2.5 is downstream of Tbx6. In distinction to its positive role in cardiac myocyte differentiation, Tbx6 knockdown augmented RA-induced differentiation of P19CL6 cells to both neurons and glia, and accelerated the rate of neurite formation. Conversely, Tbx6 overexpression attenuated differentiation to neural lineages. Thus, in the P19CL6 model, Tbx6 is required for cardiac myocyte differentiation and represses neural differentiation. We propose a model in which Tbx6 is a part of a molecular switch that modulates divergent differentiation programs within a single progenitor cell.

Low-dose mineralocorticoid receptor antagonists reduce morbidity and mortality in patients with heart failure and myocardial infarction, despite normal plasma aldosterone levels. Since apoptosis plays an important role in heart failure and postinfarction left ventricular remodeling, we examined whether low-dose mineralocorticoid receptor antagonists modulate cardiomyocyte death by regulating the apoptosis repressor protein apoptosis repressor with caspase recruitment domain to lessen the extent of apoptosis. Hearts from adult male Sprague-Dawley rats were subjected to regional ischemia followed by reperfusion ex vivo, with mineralocorticoid receptor antagonists added to perfusates before ischemia. Low-dose spironolactone (10 nmol/L) or eplerenone (100 nmol/L) significantly reduced infarct size. Spironolactone also prevented cleavage of the apoptotic chromatin condensation inducer in the nucleus and of the inhibitor of caspase-activated DNAse induced by ischemia-reperfusion, thereby abolishing chromatin condensation and internucleosomal cleavage. Ischemia-reperfusion–induced activation of caspases 2, 3, and 9, but not caspase 8, was prevented by spironolactone, suggesting targeted regulation of the intrinsic pathway. Low-dose spironolactone and eplerenone prevented loss of the apoptosis repressor with the caspase recruitment domain and reduced myocyte death. In H9c2 cells, mineralocorticoid receptor activation by aldosterone resulted in apoptosis repressor with caspase recruitment domain degradation and enhanced apoptosis; these actions were prevented by coadministration of spironolactone. Using a triple lysine mutant we identified that aldosterone enhances posttranscriptional degradation of the apoptosis repressor with a caspase recruitment domain via the ubiquitin-proteasomal pathway. Our data demonstrate that low-dose mineralocorticoid receptor antagonists reduce infarct size and apoptosis in the reperfused myocardium by preventing the apoptosis repressor with caspase recruitment domain degradation.