Melatonin alleviates cardiac fibrosis via inhibiting lncRNA MALAT1/miR‐141‐mediated NLRP3 inflammasome and TGF‐β1/Smads signaling in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a common complication of diabetes mellitus (DM), resulting in high mortality. Myocardial fibrosis, cardiomyocyte apoptosis and inflammatory cell infiltration are hallmarks of DCM, leading to cardiac dysfunction. To date, few effective approaches have been developed for the intervention of DCM. In the present study, we investigate the effect of krill oil (KO) on the prevention of DCM using a mouse model of DM induced by streptozotocin and a high-fat diet. The diabetic mice developed pathological features, including cardiac fibrosis, apoptosis and inflammatory cell infiltration, the effects of which were remarkably prevented by KO. Mechanistically, KO reversed the DM-induced cardiac expression of profibrotic and proinflammatory genes and attenuated DM-enhanced cardiac oxidative stress. Notably, KO exhibited a potent inhibitory effect on NLR family pyrin domain containing 3 (NLRP3) inflammasome that plays an important role in DCM. Further investigation showed that KO significantly upregulated the expression of Sirtuin 3 (SIRT3) and peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), which are negative regulators of NLRP3. The present study reports for the first time the preventive effect of KO on the pathological injuries of DCM, providing SIRT3, PGC-1α and NLRP3 as molecular targets of KO. This work suggests that KO supplementation may be a viable approach in clinical prevention of DCM.

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Pyrroloquinoline quinone ameliorates diabetic cardiomyopathy by inhibiting the pyroptosis signaling pathway in C57BL/6 mice and AC16 cells

European Journal of Nutrition ◽

10.1007/s00394-021-02768-w ◽

2022 ◽

Author(s):

Xue-feng Qu ◽

Bing-zhong Zhai ◽

Wen-li Hu ◽

Min-han Lou ◽

Yi-hao Chen ◽

...

Keyword(s):

Myocardial Fibrosis ◽

Diabetic Cardiomyopathy ◽

Nlrp3 Inflammasome ◽

High Glucose ◽

Cardiac Fibrosis ◽

Myocardial Hypertrophy ◽

Underlying Mechanism ◽

Pyrroloquinoline Quinone ◽

Ros Generation ◽

Protective Effects

Abstract Purpose Diabetic cardiomyopathy (DCM), a common complication of diabetes mellitus and is characterized by myocardial hypertrophy and myocardial fibrosis. Pyrroloquinoline quinone (PQQ), a natural nutrient, exerts strong protection against various myocardial diseases. Pyroptosis, a type of inflammation-related programmed cell death, is vital to the development of DCM. However, the protective effects of PQQ against DCM and the associated mechanisms are not clear. This study aimed to investigate whether PQQ protected against DCM and to determine the underlying molecular mechanism. Methods Diabetes was induced in mice by intraperitoneal injection of streptozotocin, after which the mice were administered PQQ orally (10, 20, or 40 mg/kg body weight/day) for 12 weeks. AC16 human myocardial cells were divided into the following groups and treated accordingly: control (5.5 mmol/L glucose), high glucose (35 mmol/L glucose), and HG + PQQ groups (1 and 10 nmol/L PQQ). Cells were treated for 24 h. Results PQQ reduced myocardial hypertrophy and the area of myocardial fibrosis, which was accompanied by an increase in antioxidant function and a decrease in inflammatory cytokine levels. Moreover, myocardial hypertrophy—(ANP and BNP), myocardial fibrosis—(collagen I and TGF-β1), and pyroptosis-related protein levels decreased in the PQQ treatment groups. Furthermore, PQQ abolished mitochondrial dysfunction and the activation of NF-κB/IκB, and decreased NLRP3 inflammation-mediated pyroptosis in AC16 cells under high-glucose conditions. Conclusion PQQ improved DCM in diabetic mice by inhibiting NF-κB/NLRP3 inflammasome-mediated cell pyroptosis. Long-term dietary supplementation with PQQ may be greatly beneficial for the treatment of DCM. Graphical abstract Diagram of the underlying mechanism of the effects of PQQ on DCM. PQQ inhibits ROS generation and NF-κB activation, which stimulates activation of the NLRP3 inflammasome and regulates the expression of caspase-1, IL-1β, and IL-18. The up-regulated inflammatory cytokines trigger myocardial hypertrophy and cardiac fibrosis and promote the pathological process of DCM.

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GW28-e0445 Triptolide attenuates cardiac fibrosis via NLRP3 inflammasome-mediated MAPK/TGF-β1/Smad pathway

Journal of the American College of Cardiology ◽

10.1016/j.jacc.2017.07.204 ◽

2017 ◽

Vol 70 (16) ◽

pp. C59-C60

Author(s):

Xichun Pan ◽

Haigang Zhang

Keyword(s):

Nlrp3 Inflammasome ◽

Cardiac Fibrosis ◽

Smad Pathway ◽

Tgf Β1

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The potential regulatory role of hsa_circ_0004104 in the persistency of atrial fibrillation by promoting cardiac fibrosis via TGF-β pathway

BMC Cardiovascular Disorders ◽

10.1186/s12872-021-01847-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yuanfeng Gao ◽

Ye Liu ◽

Yuan Fu ◽

Qianhui Wang ◽

Zheng Liu ◽

...

Keyword(s):

Cardiac Fibrosis ◽

Expression Patterns ◽

In Silico Analysis ◽

Significant Negative Correlation ◽

Circular Rnas ◽

Tgf Beta ◽

Rt Pcr ◽

Derivation Cohort ◽

Tgf Β1

Abstract Introduction The progression of paroxysmal AF (PAF) to persistent AF (PsAF) worsens the prognosis of AF, but its underlying mechanisms remain elusive. Recently, circular RNAs (circRNAs) were reported to be associated with cardiac fibrosis. In case of the vital role of cardiac fibrosis in AF persistency, we hypothesis that circRNAs may be potential regulators in the process of AF progression. Materials and methods 6 persistent and 6 paroxysmal AF patients were enrolled as derivation cohort. Plasma circRNAs expressions were determined by microarray and validated by RT-PCR. Fibrosis level, manifested by serum TGF-β, was determined by ELISA. Pathways and related non-coding RNAs involving in the progression of AF regulated were predicted by in silico analysis. Results PsAF patients showed a distinct circRNAs expression profile with 92 circRNAs significantly dysregulated (fold change ≥ 2, p < 0.05), compared with PAF patients. The validity of the expression patterns was subsequently validated by RT-PCR in another 60 AF patients (30 PsAF and PAF, respectively). In addition, all the 5 up and down regulated circRNAs were clustered in MAPK and TGF-beta signaling pathway by KEGG pathway analysis. Among the 5 circRNAs, hsa_circ_0004104 was consistently downregulated in PsAF group (0.6 ± 0.33 vs 1.46 ± 0.41, p < 0.001) and predicted to target several AF and/or cardiac fibrosis related miRNAs reported by previous studies. In addition, TGF-β1 level was significantly higher in the PsAF group (5560.23 ± 1833.64 vs 2236.66 ± 914.89, p < 0.001), and hsa_circ_0004104 showed a significant negative correlation with TGF-β1 level (r = − 0.797, p < 0.001). Conclusion CircRNAs dysregulation plays vital roles in AF persistency. hsa_circ_0004104 could be a potential regulator and biomarker in AF persistency by promoting cardiac fibrosis via targeting MAPK and TGF-beta pathways.

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Abstract P233: Diabetic Cardiomyopathy is Reversed by Increased Mitochondrial Bioenergetics Due to PGC-1α Activation by EET Treatment of Obese Mice

Hypertension ◽

10.1161/hyp.68.suppl_1.p233 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Jian Cao ◽

John A McClung ◽

Shailendra P Singh ◽

Lars Bellner ◽

Maayan Waldman ◽

...

Keyword(s):

Heart Failure ◽

Insulin Resistance ◽

Oxidative Phosphorylation ◽

Mitochondrial Dysfunction ◽

Diabetic Cardiomyopathy ◽

Cardiac Fibrosis ◽

Systolic Function ◽

Control Group ◽

Protein Markers ◽

Obesity And Diabetes

Introduction: Obesity and diabetes are associated with progressive cardiac fibrosis that, sequentially, results in diastolic dysfunction, reduced contractility, and ultimately heart failure. Contributing factors include hyperglycemia, insulin resistance, mitochondrial dysfunction, and a reduction in AMPK signaling. PGC-1α activates mitochondrial biogenesis and oxidative phosphorylation and is decreased in patients with diabetes mellitus (DM). We hypothesize that an epoxyeicosatrienoic acids (EETs) agonist (EET-A) will increase PGC-1α levels in a db mouse model of DM attenuate cardiomyopathy, and prevent heart failure. Methods: Db mice (4-wks), were allowed to acclimatize for 16-wks and were then divided into 3 treatment groups for an additional 16 wks: A) control, B) EET-A 1.5mg/100g BW 2 weeks and C) EET-A-Ln-PGC-1α shRNA. Ln-PGC-1α shRNA suppressed PGC-1α protein in heart tissue by 40-50%. Oxygen consumption (VO 2 ), and blood glucose was determined. Heart tissues were harvested to measure PGC-1α, HO-1, pAMPK, PGC-1α, echocardiographic fractional shortening, mitochondrial oxidative phosphorylation (OXPHOS) and mitofusion protein markers. Results: All mice developed heart failure by the end of 16 weeks and were characterized by a decrease in myocardial contractility, an increase in insulin resistance and blood pressure, decreased VO 2 , the appearance of mitochondria dysfunction and a decrease in AMPK and downstream PGC-1α signaling. Mice treated with EET-A demonstrated an increase in PGC-1α levels, improved mitochondrial function and oxidative phosphorylation (p<0.01 vs control), increased NO bioavailability (p<0.05 vs control), and normalization of glucose metabolism, insulin levels, VO 2 and LV systolic function (p<0.05 vs control). All of these findings were suppressed by PGC-1α inhibition which was accompanied by the onset of even more severe LV dysfunction than in the control group. Conclusion: Increased EET levels result in activation of PGC-1α-HO-1 which reverses diabetes induced insulin resistance, mitochondrial dysfunction, and cardiomyopathy. EET may have potential as a powerful agent for therapeutic application in the treatment of diabetic cardiomyopathy.

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Abstract 367: Lysyl Oxidase Expression by Cardiac Fibroblasts is Regulated by Integrin-mediated Signaling

Circulation Research ◽

10.1161/res.117.suppl_1.367 ◽

2015 ◽

Vol 117 (suppl_1) ◽

Author(s):

Albert Gao ◽

Lauren D Black

Keyword(s):

Gene Expression ◽

Cardiac Fibrosis ◽

Lysyl Oxidase ◽

Cardiac Fibroblasts ◽

Therapeutic Strategies ◽

Expression Of Genes ◽

Adverse Remodeling ◽

Novel Therapeutic Strategies ◽

Free Media ◽

Tgf Β1

Cardiac fibrosis following myocardial infarction (MI) leads to reduced cardiac function, and contributes to heart failure and mortality. Recent studies shown the extent of adverse remodeling may be mitigated by therapeutic strategies which regulate cardiac fibroblast mediated-remodeling. Since cross-linking by lysyl oxidase (LOX) increases following MI and alters the mechanical properties of the infarct, it is critical to characterize how its expression is regulated by CFs post-MI. While LOX expression is attributable to TGF-β1 signaling, we hypothesize that changes in the stiffness and composition of the ECM can also alter LOX expression via integrin-mediated signaling. To investigate this, we isolated CFs from healthy left ventricle (LV) and infarcted cardiac fibroblasts (ICFs) from 1 week post-MI LV and cultured them on tissue culture plastic (TCP) and collagen I-coated plates (COL) in serum-free media for 48 hours to assess the expression of genes associated with LOX signaling, fibrosis, and myofibroblast activation. Our results show an upregulation of LOX gene expression in both CFs and ICFs when cultured on COL and this is further emphasized with the presence of TGF-β1 (Fig. 1A). Gene expression of col1α1, integrin β1 subunit and αSMA (Fig. 1B-D) also exhibit similar upregulation. Ongoing studies will investigate how altered substrate stiffness and composition affect gene expression of LOX and other genes associated with fibrosis. By understanding the effect of the physical microenvironment on the expression of fibrotic genes including LOX, we aim to develop novel therapeutic strategies to attenuate cardiac fibrosis and thus improve cardiac recovery following MI.

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Abstract MP259: The Role Of Sertad4 In Pathological Cardiac Remodeling

Circulation Research ◽

10.1161/res.129.suppl_1.mp259 ◽

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.

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