scholarly journals Role of IgE-FcεR1 in Pathological Cardiac Remodeling and Dysfunction

Circulation ◽  
2020 ◽  
Author(s):  
Hongmei Zhao ◽  
Hongqin Yang ◽  
Chi Geng ◽  
Yang Chen ◽  
Junling Pang ◽  
...  
Keyword(s):  
Cardiac Remodeling ◽  
Causative Role ◽  
Ang Ii ◽  
Rna Seq ◽  
Ige Receptor ◽  
Ige Antibodies ◽  
Serum Ige ◽  
Human And Mouse

Background: Immunoglobulin E (IgE) belongs to a class of immunoglobulins involved in immune response to specific allergens. However, the roles of IgE and IgE receptor (FcεR1) in pathological cardiac remodeling and heart failure (HF) are unknown. Methods: Serum IgE levels and cardiac IgE receptor (FcεR1) expression were assessed in diseased hearts from human and mouse. The role of FcεR1 signaling in pathological cardiac remodeling was explored in vivo by FcεR1 genetic depletion, anti-IgE antibodies, and bone-marrow (BM) transplantation. The roles of IgE-FcεR1 pathway were further evaluated in vitro in primary cultured rat cardiomyocytes (CMs) and cardiac fibroblasts (CFs). RNA-seq and bioinformatic analyses were used to identify biochemical changes and signaling pathways that are regulated by IgE/FcεR1. Results: Serum IgE levels were significantly elevated in patients with HF as well as in two mouse cardiac disease models induced by chronic pressure overload via transverse aortic contraction (TAC) and chronic angiotensin II (Ang II) infusion. Interestingly, FcεR1 expression levels were also significantly up-regulated in failing hearts from human and mouse. Blockade of the IgE-FcεR1 pathway by FcεR1 knockout alleviated TAC- or Ang II-induced pathological cardiac remodeling and/or dysfunction. Anti-IgE antibodies (including the clinical drug, omalizumab) also significantly alleviated Ang II-induced cardiac remodeling. BM transplantation experiments indicated that IgE-induced cardiac remodeling was mediated through non-BM-derived cells. FcεR1 was found to be expressed in both CMs and CFs. In cultured rat CMs, IgE-induced CM hypertrophy and hypertrophic marker expression were abolished by depleting FcεR1. In cultured rat CFs, IgE-induced CF activation and matrix protein production were also blocked by FcεR1 deficiency. RNA-seq and signaling pathway analyses revealed that transforming growth factor-β (TGF-β) may be a critical mediator and blocking TGF-β indeed alleviated IgE-induced cardiomyocyte hypertrophy and cardiac fibroblast activation in vitro . Conclusions: Our findings suggest that IgE induction plays a causative role in pathological cardiac remodeling, at least partially via the activation of IgE-FcεR1 signaling in CMs and CFs. Therapeutic strategies targeting the IgE-FcεR1 axis may be effective for managing IgE-mediated cardiac remodeling.

scholarly journals Dual Role of Integrin Alpha-6 in Glioblastoma: Supporting Stemness in Proneural Stem-Like Cells While Inducing Radioresistance in Mesenchymal Stem-Like Cells

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3055
Author(s):  
Elisabetta Stanzani ◽  
Leire Pedrosa ◽  
Guillaume Bourmeau ◽  
Oceane Anezo ◽  
Aleix Noguera-Castells ◽  
...  
Keyword(s):  
Cellular Heterogeneity ◽  
In Vitro Assays ◽  
Rna Seq ◽  
Promising Target ◽  
Damage Response ◽  
Integrin Alpha 6 ◽  
And Control ◽  
Improve Patient

Therapeutic resistance after multimodal therapy is the most relevant cause of glioblastoma (GBM) recurrence. Extensive cellular heterogeneity, mainly driven by the presence of GBM stem-like cells (GSCs), strongly correlates with patients’ prognosis and limited response to therapies. Defining the mechanisms that drive stemness and control responsiveness to therapy in a GSC-specific manner is therefore essential. Here we investigated the role of integrin a6 (ITGA6) in controlling stemness and resistance to radiotherapy in proneural and mesenchymal GSCs subtypes. Using cell sorting, gene silencing, RNA-Seq, and in vitro assays, we verified that ITGA6 expression seems crucial for proliferation and stemness of proneural GSCs, while it appears not to be relevant in mesenchymal GSCs under basal conditions. However, when challenged with a fractionated protocol of radiation therapy, comparable to that used in the clinical setting, mesenchymal GSCs were dependent on integrin a6 for survival. Specifically, GSCs with reduced levels of ITGA6 displayed a clear reduction of DNA damage response and perturbation of cell cycle pathways. These data indicate that ITGA6 inhibition is able to overcome the radioresistance of mesenchymal GSCs, while it reduces proliferation and stemness in proneural GSCs. Therefore, integrin a6 controls crucial characteristics across GBM subtypes in GBM heterogeneous biology and thus may represent a promising target to improve patient outcomes.

Novel targets of ANG II regulation in mouse heart identified by serial analysis of gene expression

2004 ◽  
Vol 287 (5) ◽  
pp. H1957-H1966 ◽  
Author(s):  
Faina Schwartz ◽  
Arvi Duka ◽  
Irena Duka ◽  
Jing Cui ◽  
Haralambos Gavras
Keyword(s):  
Gene Expression ◽  
Cardiac Remodeling ◽  
Unknown Function ◽  
Mouse Heart ◽  
Ang Ii ◽  
Coordinate Regulation ◽  
Transcriptional Changes ◽  
Novel Targets ◽  
Molecular Circuitry

Although the central role of ANG II in cardiovascular homeostasis is well appreciated, the molecular circuitry of its many actions is not completely understood. With the use of serial analysis of gene expression to assess global transcriptional changes in the heart of mice after continuous 7-day ANG II administration, we identified patterns of gene expression indicative of cardiac remodeling, including coordinate regulation of genes previously described in a context of processes associated with hypertrophy and fibrosis. In addition, we discovered several novel ANG II targets, including characterized genes of known function, recently annotated genes of unknown function, and the putative genes not yet present in current databases. The serial analysis of gene expression approach to assess the role of ANG II presented in this report provides new venues for inquiries into ANG II-mediated cardiac function.

Abstract MP259: The Role Of Sertad4 In Pathological Cardiac Remodeling

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Matthew Stratton ◽  
Ashley Francois ◽  
Oscar Bermeo-Blanco ◽  
Alessandro Canella ◽  
Lynn Marcho ◽  
...  
Keyword(s):  
Cardiac Remodeling ◽  
Cardiac Fibrosis ◽  
Systolic Function ◽  
Myocardial Infarct ◽  
Proteasome Inhibition ◽  
Rna Seq ◽  
Expression Of Genes ◽  
M Phase ◽  
Tgf Β1

Over 6 million Americans suffer from heart failure (HF) while the 5-year mortality rate following first admission for HF is over 40%. Cardiac fibrosis is a clinical hallmark of HF, regardless of the initiating pathology and is thought to contribute to disease progression. Using an epigenomics discovery approach, we uncovered a nuclear protein, Sertad4, as a potential anti-fibrotic target. Our data indicate that Sertad4 is a positive regulator of fibroblast activation. Specifically, cultured cardiac fibroblast experiments demonstrate that Sertad4 targeting with shRNAs blocks fibroblast proliferation and causes cells to arrest in the G2/M phase of the cell cycle. Also, shRNA targeting of Sertad4 dramatically blocked activation of myofibroblast differentiation genes (αSMA/POSTN/COL1A1). Mechanistically, these effects appear to be mediated by Sertad4 regulation of SMAD2 protein stability in the presence of TGF-β1 stimulation as demonstrated by proteasome inhibition experiments. RNA-seq analysis indicate that Sertad4 also regulates the expression of genes involved in ubiquitination and proteasome degradation. Next, we sought to determine the effect of global Sertad4 knockout on post-myocardial infarct (MI) remodeling and cardiac function in mice. After 4 weeks of permanent LAD ligation, echocardiography was performed to measure systolic function. Relative to wild-type (WT) controls, the Sertad4 KO mice showed preserved systolic function as evident by improved ejection fraction (WT 14.4 +/- 3.6 vs. KO 33.9+/-5.9, p=0.035) and fractional shortening (WT 6.5 +/- 1.7 vs. KO 16.4 +/- 3.4, p=0.046). β-gal staining in the Sertad4/LacZ reporter mouse subjected to MI showed robust Sertad4/LacZ expression in the ischemic scar and boarder-zone with almost no expression in control hearts. This data supports the notion that Sertad4 has a key role in cardiac remodeling in response to ischemic injury.

Abstract 445: A Pro-Fibrotic Role of Interleukin-4 in Cardiac Remodeling and Dysfunction

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Hongmei Peng ◽  
Oscar Carretero ◽  
Xiao-Ping Yang ◽  
Pablo Nakagawa ◽  
Jiang Xu ◽  
...  
Keyword(s):  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Interleukin 4 ◽  
Ang Ii ◽  
Collagen Production ◽  
And Function ◽  
First Time ◽  
Mini Pump

Elevated interleukin-4 (IL-4) levels are positively related to cardiac fibrosis in heart failure and hypertension. Using Balb/c exhibiting high circulating IL-4, Balb/c- Il4 tm2Nnt (IL-4 knockout with Balb/c background, IL-4 -/- ) and C57BL/6 mice, as well as cultured cardiac fibroblasts (CFs), we hypothesized that 1) high levels of IL-4 result in cardiac fibrosis, making the heart susceptible to angiotensin II (Ang II)-induced damage, and 2) IL-4 potently stimulates collagen production by CFs. Each strain (9- to 12-week old male) received vehicle or Ang II (1.4 mg/kg/day, s.c. via osmotic mini-pump) for 8 weeks. Cardiac fibrosis and function were determined by histology and echocardiography, respectively. Compared to C57BL/6, Balb/c mice had doubled interstitial collagen in the heart, enlarged left ventricle and decreased cardiac function along with elevated cardiac IL-4 protein (1.00±0.08 in C57BL/6 vs 2.61±0.46 in Balb/c, p <0.05); all those changes were significantly attenuated in IL-4 -/- (Table 1). Ang II further deteriorated cardiac fibrosis and dysfunction in Balb/c; these detrimental effects were attenuated in IL-4 -/- , although the three strains had a similar level of hypertension. In vitro study revealed that IL-4Rα was constitutively expressed in CFs (Western blot), and IL-4 potently stimulated collagen production by CFs (hydroxproline assay, from 18.89±0.85 to 38.81±3.61 μg/mg at 10 ng/ml, p <0.01). Our study demonstrates for the first time that IL-4, as a potent pro-fibrotic cytokine in the heart, contributes to cardiac fibrotic remodeling and dysfunction. Thus IL-4 may be a potential therapeutic target for cardiac fibrosis and dysfunction.

P–182 The mechanism of mouse embryo hatching and the impact of laser drilling the zona pellucida: an RNA sequencing study

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Y Liu ◽  
C Jones ◽  
K Coward
Keyword(s):  
Treatment Group ◽  
Mouse Embryo ◽  
Mouse Embryos ◽  
Z Score ◽  
Rna Seq ◽  
Metabolism Pathway ◽  
Hatching Process ◽  
The Impact

Abstract Study question What is the mechanism of embryo hatching? Will laser-assisted zona pellucida (ZP) drilling alter the embryonic transcriptome? Summary answer Hatching is an ATP-dependent process. Hatching is also associated with Rho-mediated signaling. Laser-assisted ZP drilling might cause alternation in embryo metabolism. What is known already Embryo hatching is a vital process for early embryo development and implantation. Animal data suggests that hatching is the result of multiple factors, such as mechanical pressure, protease activation, and the regulation of maternal secretions. However, little is known about the regulatory signaling mechanisms and the molecules involved. In addition, despite the extensive use of laser-assisted ZP drilling in the clinic, the safety profile of this technique at molecular level is very sparse. The impact of this technique on the embryonic transcriptome has not been studied systematically. Study design, size, duration Eighty mouse embryos were randomly divided into a laser ZP drilling group (n = 40) and an untreated group (n = 40). After treatment, embryos were cultured in vitro for two days. Then, hatching blastocyst (n = 8) and pre-hatching blastocyst (n = 8) from the untreated group, and the hatching blastocyst from the treatment group (n = 8) were processed for RNA sequencing (RNA-seq). Participants/materials, setting, methods Cryopreserved 8-cell stage mouse embryos (B6C3F1 × B6D2F1) were thawed, and a laser was used to drill the embryo ZP in the treatment group. Next, the treated and untreated embryos were individually cultured in vitro to the E4.5 blastocyst stage. The resulting blastocysts were lysed individually and used for subsequent cDNA library preparation and RNA-seq. Following data quality control and alignment, the RNA-seq data were processed for differentially expressed gene analysis and downstream functional analysis. Main results and the role of chance According to the RNA-seq data, 275 differentially expressed genes (DEGs) (230 up-regulated and 45 down-regulated, adjusted P &lt; 0.05) were identified when comparing hatching and pre-hatching blastocysts in the control groups. Analysis suggested that the trophectoderm is the primary cell type involved in hatching, and revealed the potential molecules causing increased blastocyst hydrostatic pressure (Aqp3 and Cldn4). Functional enrichment analysis suggested that ATP metabolism and protein synthesis were activated in hatching blastocysts. DEGs were found to be significantly enriched in several gene ontology terms, particularly in terms of the organization of the cytoskeleton and actin polymerisation (P &lt; 0.0001). Furthermore, according to QIAGEN ingenuity pathway analysis results, Rho signaling was implicated in blastocyst hatching (Actb, Arpc2, Cfl1, Myl6, Pfn1, Rnd3, Septin9, z-score=2.65, P &lt; 0.0001). Moreover, the potential role of hormones (estrogen (z-score=2.24) and prolactin (z-score=2.4)) and growth factors (AGT (z-score=2.41) and FGF2 (z-score=2.213)) were implicated in the hatching process as indicated by the upstream regulator analysis. By comparing the transcriptome between laser-treated and untreated hatching blastocysts, 47 DEGs were identified (adjusted P &lt; 0.05) following laser-assisted ZP drilling. These genes were enriched in metabolism-related pathways (P &lt; 0.05), including the lipid metabolism pathway (Mvd, Mvk, Aacs, Gsk3a, Pik3c2a, Aldh9a1) and the xenobiotic metabolism pathway (Aldh18a1, Aldh9a1, Keap1, and Pik3c2a). Limitations, reasons for caution Findings in mouse embryos may not be fully representative of human embryos. Furthermore, the mechanism of hatching revealed here might only reflect the hatching process of embryos in vitro. Further studies are now necessary to confirm these findings in different conditions and species to determine their clinical significance. Wider implications of the findings: Our study profiled the mouse embryo transcriptome during in vitro hatching, identified potential key genes and mechanisms for future study. In addition, for the first time, we revealed the impact of laser-assisted ZP drilling on the transcriptome, this may help us to assess and improve the existing technique. Trial registration number Not applicable

Abstract 17285: A Selective Transforming Growth Factor-β and Growth Differentiation Factor-15 Ligand Trap Attenuates Pulmonary Hypertension

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Lai-Ming Yung ◽  
Samuel D Paskin-Flerlage ◽  
Ivana Nikolic ◽  
Scott Pearsall ◽  
Ravindra Kumar ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Rna Seq ◽  
Differentiation Factor ◽  
Group I ◽  
Tgf Β1

Introduction: Excessive Transforming Growth Factor-β (TGF-β) signaling has been implicated in pulmonary arterial hypertension (PAH), based on activation of TGF-β effectors and transcriptional targets in affected lungs and the ability of TGF-β type I receptor (ALK5) inhibitors to improve experimental PAH. However, clinical use of ALK5 inhibitors has been limited by cardiovascular toxicity. Hypothesis: We tested whether or not selective blockade of TGF-β and Growth Differentiation Factor (GDF) ligands using a recombinant TGFβ type II receptor extracellular domain Fc fusion protein (TGFBRII-Fc) could impact experimental PAH. Methods: Male SD rats were injected with monocrotaline (MCT) and received vehicle or TGFBRII-Fc (15 mg/kg, twice per week, i.p.). C57BL/6 mice were treated with SU-5416 and hypoxia (SUGEN-HX) and received vehicle or TGFBRII-Fc. RNA-Seq was used to profile transcriptional changes in lungs of MCT rats. Circulating levels of GDF-15 were measured in 241 PAH patients and 41 healthy controls. Human pulmonary artery smooth muscle cells were used to examine signaling in vitro . Results: TGFBRII-Fc is a selective ligand trap, inhibiting the ability of GDF-15, TGF-β1, TGF-β3, but not TGF-β2 to activate SMAD2/3 in vitro . In MCT rats, prophylactic treatment with TGFBRII-Fc normalized expression of TGF-β transcriptional target PAI-1, attenuated PAH and vascular remodeling. Delayed administration of TGFBRII-Fc in rats with established PAH at 2.5 weeks led to improved survival, decreased PAH and remodeling at 5 weeks. Similar findings were observed in SUGEN-HX mice. No valvular abnormalities were found with TGFBRII-Fc treatment. RNA-Seq revealed GDF-15 to be the most highly upregulated TGF-β ligand in the lungs of MCT rats, with only modest increases in TGF-β1 and no change in TGF-β2/3 observed, suggesting a dominant role of GDF-15 in the pathophysiology of this model. Plasma levels of GDF-15 were significantly increased in patients with diverse etiologies of WHO Group I PAH. Conclusions: These findings demonstrate that a selective TGF-β/GDF-15 trap attenuates experimental PAH, remodeling and mortality, without causing valvulopathy. These data highlight the potential role of GDF-15 as a pathogenic molecule and therapeutic target in PAH.

Dissociation in plasma renin and adrenal ANG II and aldosterone responses to sodium restriction in rats

1991 ◽  
Vol 261 (4) ◽  
pp. E487-E494 ◽  
Author(s):  
A. Menachery ◽  
L. M. Braley ◽  
I. Kifor ◽  
R. Gleason ◽  
G. H. Williams
Keyword(s):  
Plasma Renin ◽  
Fold Increase ◽  
Plasma Aldosterone ◽  
Delayed Response ◽  
Ang Ii ◽  
Sodium Restriction ◽  
Sodium Depletion ◽  
Pathway Activity

In rats, plasma renin activity (PRA) increases sharply, reaching a plateau within hours of sodium restriction. Plasma aldosterone increases gradually, not reaching a plateau for 1-2 days. To determine whether this dissociation is secondary to the time needed to modify adrenal sensitivity to angiotensin II (ANG II) and to assess the role of locally produced ANG II in this process, rats were salt restricted for 0-120 h. Plasma hormone levels were assessed, adrenal ANG II was measured, and basal and ANG II (1 x 10(-8) M)-stimulated steroidogenesis were determined in vitro. Although PRA attained an elevated plateau within 8 h, plasma aldosterone did not peak until after 48 h of sodium depletion. The in vitro aldosterone sensitivity to exogenous ANG II was not apparent until rats had been salt restricted for 16 h. A plateau (4-fold increase above the ANG II response on high salt) was achieved between 24 and 48 h. Adrenal ANG II also exhibited a similar delayed response that correlates significantly with changes in aldosterone biosynthesis and late pathway activity. Thus the dissociation between PRA and plasma aldosterone may be secondary to a lag in the zona glomerulosa's (ZG) steroidogenic response to ANG II as well as a parallel lag in tissue ANG II production, suggesting that changes in tissue ANG II may mediate ZG sensitivity to ANG II during sodium deprivation.

scholarly journals HIF-1α contributes to Ang II-induced inflammatory cytokine production in podocytes

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Hao Huang ◽  
Yanqin Fan ◽  
Zhao Gao ◽  
Wei Wang ◽  
Ning Shao ◽  
...  
Keyword(s):  
Hypoxia Inducible Factor ◽  
Renin Angiotensin System ◽  
Inflammatory Factors ◽  
Ang Ii ◽  
Angiotensin System ◽  
Inflammatory Injury ◽  
Tnf Α

Abstract Background Studies have indicated that changed expression of hypoxia-inducible factor-1α (HIF-1α) in epithelial cells from the kidney could affect the renal function in chronic kidney disease (CKD). As Angiotensin II (Ang II) is a critical active effector in the renin-angiotensin system (RAS) and was proved to be closely related to the inflammatory injury. Meanwhile, researchers found that Ang II could alter the expression of HIF-1α in the kidney. However, whether HIF-1α is involved in mediating Ang II-induced inflammatory injury in podocytes is not clear. Methods Ang II perfusion animal model were established to assess the potential role of HIF-1α in renal injury in vivo. Ang II stimulated podocytes to observe the corresponding between HIF-1α and inflammatory factors in vitro. Results The expression of inflammatory cytokines such as MCP-1 and TNF-α was increased in the glomeruli from rats treated with Ang II infusion compared with control rats. Increased HIF-1α expression in the glomeruli was also observed in Ang II-infused rats. In vitro, Ang II upregulated the expression of HIF-1α in podocytes. Furthermore, knockdown of HIF-1α by siRNA decreased the expression of MCP-1 and TNF-α. Moreover, HIF-1α siRNA significantly diminished the Ang II-induced overexpression of HIF-1α. Conclusion Collectively, our results suggest that HIF-1α participates in the inflammatory response process caused by Ang II and that downregulation of HIF-1α may be able to partially protect or reverse inflammatory injury in podocytes.

scholarly journals Association of intronic DNA methylation and hydroxymethylation alterations in the epigenetic etiology of dilated cardiomyopathy

2019 ◽  
Vol 317 (1) ◽  
pp. H168-H180 ◽  
Author(s):  
Ali M. Tabish ◽  
Mohammed Arif ◽  
Taejeong Song ◽  
Zaher Elbeck ◽  
Richard C. Becker ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Dilated Cardiomyopathy ◽  
Cardiac Remodeling ◽  
Rna Seq ◽  
Wild Type ◽  
Kegg Pathways ◽  
Wild Type Phenotype ◽  
Gene Expression Levels

In this study, we investigated the role of DNA methylation [5-methylcytosine (5mC)] and 5-hydroxymethylcytosine (5hmC), epigenetic modifications that regulate gene activity, in dilated cardiomyopathy (DCM). A MYBPC3 mutant mouse model of DCM was compared with wild type and used to profile genomic 5mC and 5hmC changes by Chip-seq, and gene expression levels were analyzed by RNA-seq. Both 5mC-altered genes (957) and 5hmC-altered genes (2,022) were identified in DCM hearts. Diverse gene ontology and KEGG pathways were enriched for DCM phenotypes, such as inflammation, tissue fibrosis, cell death, cardiac remodeling, cardiomyocyte growth, and differentiation, as well as sarcomere structure. Hierarchical clustering of mapped genes affected by 5mC and 5hmC clearly differentiated DCM from wild-type phenotype. Based on these data, we propose that genomewide 5mC and 5hmC contents may play a major role in DCM pathogenesis. NEW & NOTEWORTHY Our data demonstrate that development of dilated cardiomyopathy in mice is associated with significant epigenetic changes, specifically in intronic regions, which, when combined with gene expression profiling data, highlight key signaling pathways involved in pathological cardiac remodeling and heart contractile dysfunction.

scholarly journals Phosphodiesterase 5 inhibition ameliorates angiontensin II-induced podocyte dysmotility via the protein kinase G-mediated downregulation of TRPC6 activity

2014 ◽  
Vol 306 (12) ◽  
pp. F1442-F1450 ◽  
Author(s):  
Gentzon Hall ◽  
Janelle Rowell ◽  
Federica Farinelli ◽  
Rasheed A. Gbadegesin ◽  
Peter Lavin ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Soluble Guanylate Cyclase ◽  
Pde5 Inhibitor ◽  
Receptor Potential ◽  
Nitric Oxide Donor ◽  
Ang Ii ◽  
Calcineurin Phosphatase ◽  
Phosphodiesterase 5

The emerging role of the transient receptor potential cation channel isotype 6 (TRPC6) as a central contributor to various pathological processes affecting podocytes has generated interest in the development of therapeutics to modulate its function. Recent insights into the regulation of TRPC6 have revealed PKG as a potent negative modulator of TRPC6 conductance and associated signaling via its phosphorylation at two highly conserved amino acid residues: Thr69/Thr70 (Thr69 in mice and Thr70 in humans) and Ser321/Ser322 (Ser321 in mice and Ser322 in humans). Here, we tested the role of PKG in modulating TRPC6-dependent responses in primary and conditionally immortalized mouse podocytes. TRPC6 was phosphorylated at Thr69 in nonstimulated podocytes, but this declined upon ANG II stimulation or overexpression of constitutively active calcineurin phosphatase. ANG II induced podocyte motility in an in vitro wound assay, and this was reduced 30–60% in cells overexpressing a phosphomimetic mutant TRPC6 (TRPC6T70E/S322E) or activated PKG ( P < 0.05). Pretreatment of podocytes with the PKG agonists S-nitroso- N-acetyl-dl-penicillamine (nitric oxide donor), 8-bromo-cGMP, Bay 41–2772 (soluble guanylate cyclase activator), or phosphodiesterase 5 (PDE5) inhibitor 4-{[3′,4′-(methylenedioxy)benzyl]amino}[7]-6-methoxyquinazoline attenuated ANG II-induced Thr69 dephosphorylation and also inhibited TRPC6-dependent podocyte motility by 30–60%. These data reveal that PKG activation strategies, including PDE5 inhibition, ameliorate ANG II-induced podocyte dysmotility by targeting TRPC6 in podocytes, highlighting the potential therapeutic utility of these approaches to treat hyperactive TRPC6-dependent glomerular disease.

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