Inhibitory effects of oxymatrine on TGF‑β1‑induced proliferation and abnormal differentiation in rat cardiac fibroblasts via the p38MAPK and ERK1/2 signaling pathways

Targeting MAPK-ERK/JNK pathway: A potential intervention mechanism of myocardial fibrosis in heart failure

Myocardial fibrosis is a significant pathological basis of heart failure. Overactivation of the ERK1/2 and JNK1/2 signaling pathways of MAPK family members synergistically promotes the proliferation of myocardial fibroblasts and accelerates the development of myocardial fibrosis. In addition to some small molecule inhibitors and Western drugs, many Chinese medicines can also inhibit the activity of ERK1/2 and JNK1/2, thus slowing down the development of myocardial fibrosis, and are generally safe and effective. However, the specific biological mechanisms of ERK1/2 and JNK1/2 signaling pathways in myocardial fibrosis still need to be fully understood, and there is no systematic review of existing drugs and methods to inhibit them from improving myocardial fibrosis. This study aims to summarize the roles and cross-linking mechanisms of ERK1/2 and JNK1/2 signaling pathways in myocardial fibrosis and to systematically sort out the small-molecule inhibitors, Western drugs, traditional Chinese medicines, and non-pharmacological therapies that inhibit ERK1/2 and JNK1/2 to alleviate myocardial fibrosis. In the future, we hope to conduct more in-depth research from the perspective of precision-targeted therapy, using this as a basis for developing new drugs that provide new perspectives on the prevention and treatment of heart failure.

SGLT1: A Potential Drug Target for Cardiovascular Disease

SGLT1 and SGLT2 are the two main members of the sodium-glucose cotransporters (SGLTs), which are mainly responsible for glucose reabsorption in the body. In recent years, many large clinical trials have shown that SGLT2 inhibitors have cardiovascular protection for diabetic and non-diabetic patients independent of lowering blood glucose. However, SGLT2 was barely detected in the hearts of humans and animals, while SGLT1 was highly expressed in myocardium. As SGLT2 inhibitors also have a moderate inhibitory effect on SGLT1, the cardiovascular protection of SGLT2 inhibitors may be due to SGLT1 inhibition. SGLT1 expression is associated with pathological processes such as cardiac oxidative stress, inflammation, fibrosis, and cell apoptosis, as well as mitochondrial dysfunction. The purpose of this review is to summarize the protective effects of SGLT1 inhibition on hearts in various cell types, including cardiomyocytes, endothelial cells, and fibroblasts in preclinical studies, and to highlight the underlying molecular mechanisms of protection against cardiovascular diseases. Selective SGLT1 inhibitors could be considered a class of drugs for cardiac-specific therapy in the future.

Oxymatrine and insulin resistance: Focusing on mechanistic intricacies involve in diabetes associated cardiomyopathy via SIRT1/AMPK and TGF-β signaling pathway

Cardiomyopathy (CDM) and related morbidity and mortality are increasing at an alarming rate, in large part because of the increase in the number of diabetes mellitus cases. The clinical consequence associated with CDM is heart failure (HF) and is considerably worse for patients with diabetes mellitus, as compared to nondiabetics. Diabetic cardiomyopathy (DCM) is characterized by structural and functional malfunctioning of the heart, which includes diastolic dysfunction followed by systolic dysfunction, myocyte hypertrophy, cardiac dysfunctional remodeling, and myocardial fibrosis. Indeed, many reports in the literature indicate that various signaling pathways, such as the AMP-activated protein kinase (AMPK), silent information regulator 1 (SIRT1), PI3K/Akt, and TGF-β/smad pathways, are involved in diabetes-related cardiomyopathy, which increases the risk of functional and structural abnormalities of the heart. Therefore, targeting these pathways augments the prevention as well as treatment of patients with DCM. Alternative pharmacotherapy, such as that using natural compounds, has been shown to have promising therapeutic effects. Thus, this article reviews the potential role of the quinazoline alkaloid, oxymatrine obtained from the Sophora flavescensin CDM associated with diabetes mellitus. Numerous studies have given a therapeutic glimpse of the role of oxymatrine in the multiple secondary complications related to diabetes, such as retinopathy, nephropathy, stroke, and cardiovascular complications via reductions in oxidative stress, inflammation, and metabolic dysregulation, which might be due to targeting signaling pathways, such as AMPK, SIRT1, PI3K/Akt, and TGF-β pathways. Thus, these pathways are considered central regulators of diabetes and its secondary complications, and targeting these pathways with oxymatrine might provide a therapeutic tool for the diagnosis and treatment of diabetes-associated cardiomyopathy.

Therapeutic opportunities for senolysis in cardiovascular disease

Cellular senescence within the cardiovascular system has, until recently, been understudied and unappreciated as a factor in the development of age-related cardiovascular diseases such as heart failure, myocardial infarction and atherosclerosis. This is in part due to challenges with defining senescence within post-mitotic cells such as cardiomyocytes. However, recent evidence has demonstrated senescent-like changes, including a senescence-associated secretory phenotype (SASP), in cardiomyocytes in response to ageing and cell stress. Other replicating cells, including fibroblasts and vascular smooth muscle cells, within the cardiovascular system have also been shown to undergo senescence and contribute to disease pathogenesis. These findings coupled with the emergence of senolytic therapies, to target and eliminate senescent cells, have provided fascinating new avenues for management of several age-related cardiovascular diseases with high prevalence. In this review, we discuss the role of senescent cells within the cardiovascular system and highlight the contribution of senescence cells to common cardiovascular diseases. We discuss the emerging role for senolytics in cardiovascular disease management while highlighting important aspects of senescence biology which must be clarified before the potential of senolytics can be fully realized.

Oxymatrine attenuated isoproterenol-induced heart failure via the TLR4/NF-κB and MAPK pathways in vivo and in vitro

Oxymatrine (OMT) is a quinoline alkaloid isolated from the root of the Sophora flavescens that has a variety of biological activities. However, the effect and potential mechanism of OMT on isoproterenol (ISO)-induced heart failure (HF) are not clear. In this study, we found that OMT improved the survival of HL-1 cells induced by ISO. We also demonstrated that OMT significantly inhibited the levels of the inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). OMT decreased the levels of the TLR4 and reduced the phosphorylation levels of nuclear factor-κB (NF-κB) inhibitor (IκB), p65, c-Jun N-terminal kinases (JNK) and p38. The inhibitory effect of the TLR4 inhibitor TAK242 on HL-1 cells was evaluated. The results showed that the effect of OMT on the phosphorylation levels of IκBα and p65 was enhanced in HL-1 cells treated with TAK242. Using animal models, OMT significantly reduced ISO-induced cardiac injury, myocardial necrosis, interstitial edema, and fibrosis. In addition, OMT attenuated TNF-α and IL-6 and inhibited the expression of TLR4/NF-κB and MAPK pathway-related proteins. This finding suggests that OMT may alleviate HF by interfering with the TLR4/NF-κB and MAPK pathways.

Effect of SNHG11/miR-7-5p/PLCB1 Axis on Acute Pancreatitis through Inhibiting p38MAPK Pathway

Acute pancreatitis (AP) is an inflammatory disease of the pancreas. A growing number of studies have shown that long noncoding RNAs (lncRNAs) play an important role in AP progression. Here, we aimed to elucidate the role of Small Nucleolar RNA Host Gene 11(SNHG11) and its underlying molecular mechanisms behind AP progression. The in vivo and in vitro AP cell models were established by retrograde injection of sodium taurocholate and caerulein stimulation into AR42J cells and HPDE6-C7 cells, respectively. A bioinformatics website predicted the relationship between SNHG11, miR-7-5p, and Phospholipase C Beta 1(PLCB1) and validated it with a dual-luciferase reporter assay and an RNA immunoprecipitation (RIP) assay. AR42J cells and HPDE6-C7 cells were transfected with an overexpression of plasmids or shRNA to investigate the effects of the SNHG11/miR-7-5p/PLCB1 axis on cell proliferation and apoptosis, inflammatory cytokine secretion, and acute pancreatitis. Low expression of SNHG11 and PLCB1 and high expression of miR-7-5p were observed in AP pancreatic tissue and AP cell models. SNHG11 overexpression inhibited apoptosis and inflammatory responses induced by caerulein. Simultaneously, we discovered that SNHG11 regulates PLCB1 expression by sponging miR-7-5p. PLCB1 overexpression abrogated inflammatory damage exacerbated by miR-7-5p enrichment. In addition, the SNHG11/miR-7-5p/PLCB1 axis could be involved in caerulein-induced inflammatory injury by participating in the p38MAPK signaling pathway. The overexpressed SNHG11/miR-7-5p/PLCB1 axis can inhibit AP progression by participating in the p38MAPK signaling pathway, thereby providing a potential therapeutic target and therapeutic direction for AP therapy.

A Cyclopentanone Compound Attenuates the Over-Accumulation of Extracellular Matrix and Fibrosis in Diabetic Nephropathy via Downregulating the TGF-β/p38MAPK Axis

Excessive accumulation of the extracellular matrix (ECM) is a crucial pathological process in chronic kidney diseases, such as diabetic nephropathy, etc. The underlying mechanisms of how to decrease ECM deposition to improve diabetic nephropathy remain elusive. The present study investigated whether cyclopentanone compound H8 alleviated ECM over-deposition and fibrosis to prevent and treat diabetic nephropathy. HK-2 cell viability after treatment with H8 was measured by an MTT assay. ECM alterations and renal fibrosis were identified in vitro and in vivo. A pharmacological antagonist was used to detect associations between H8 and the p38 mitogen-activated protein kinase (p38MAPK) signaling pathway. H8 binding was identified through computer simulation methods. Studies conducted on high glucose and transforming growth factor β1 (TGF-β1)-stimulated HK-2 cells revealed that the p38MAPK inhibitor SB 202190 and H8 had similar pharmacological effects. In addition, excessive ECM accumulation and fibrosis in diabetic nephropathy were remarkably improved after H8 administration in vivo and in vitro. Finally, the two molecular docking models further proved that H8 is a specific p38MAPK inhibitor that forms a hydrogen bond with the LYS-53 residue of p38MAPK. The cyclopentanone compound H8 alleviated the over-deposition of ECM and the development of fibrosis in diabetic nephropathy by suppressing the TGF-β/p38MAPK axis.

Fibrotic Signaling in Cardiac Fibroblasts and Vascular Smooth Muscle Cells: The Dual Roles of Fibrosis in HFpEF and CAD

Patients with heart failure with preserved ejection fraction (HFpEF) and atherosclerosis-driven coronary artery disease (CAD) will have ongoing fibrotic remodeling both in the myocardium and in atherosclerotic plaques. However, the functional consequences of fibrosis differ for each location. Thus, cardiac fibrosis leads to myocardial stiffening, thereby compromising cardiac function, while fibrotic remodeling stabilizes the atherosclerotic plaque, thereby reducing the risk of plaque rupture. Although there are currently no drugs targeting cardiac fibrosis, it is a field under intense investigation, and future drugs must take these considerations into account. To explore similarities and differences of fibrotic remodeling at these two locations of the heart, we review the signaling pathways that are activated in the main extracellular matrix (ECM)-producing cells, namely human cardiac fibroblasts (CFs) and vascular smooth muscle cells (VSMCs). Although these signaling pathways are highly overlapping and context-dependent, effects on ECM remodeling mainly act through two core signaling cascades: TGF-β and Angiotensin II. We complete this by summarizing the knowledge gained from clinical trials targeting these two central fibrotic pathways.

Suberoylanilide hydroxamic acid (SAHA) inhibits transforming growth factor-beta 2-induced increases in aqueous humor outflow resistance

Transforming growth factor-beta 2 (TGF-β2) is highly concentrated in the aqueous humor of primary open-angle glaucoma patients. TGF-β2 causes fibrosis of outflow tissues, such as the trabecular meshwork (TM), and increases intraocular pressure by increasing resistance to aqueous humor outflow. Recently, histone deacetylase (HDAC) activity was investigated in fibrosis in various tissues, revealing that HDAC inhibitors suppress tissue fibrosis. However, the effect of HDAC inhibitors on fibrosis in the eye was not determined. Here, we investigated the effect of suberoylanilide hydroxamic acid (SAHA), an HDAC inhibitor, on TGF-β2-induced increased resistance to aqueous humor outflow. We found that SAHA suppressed TGF-β2-induced outflow resistance in perfused porcine eyes. Moreover, SAHA cotreatment suppressed TGF-β2-induced ocular hypertension in rabbits. The permeability of monkey TM (MTM) and Schlemm’s canal (MSC) cell monolayers was decreased by TGF-β2 treatment. SAHA inhibited the effects of TGF-β2 on the permeability of these cells. TGF-β2 also increased the expression of extracellular matrix proteins (fibronectin and collagen type I or IV) in MTM, MSC, and human TM (HTM) cells, while SAHA inhibited TGF-β2-induced extracellular matrix protein expression in these cells. SAHA also inhibited TGF-β2-induced phosphorylation of Akt and ERK, but did not inhibit Smad2/3 phosphorylation, the canonical pathway of TGF-β signaling. Moreover, SAHA induced the expression of phosphatase and tensin homolog, a PI3K/Akt signaling factor, as well as bone morphogenetic protein 7, an endogenous antagonist of TGF-β. These results imply that SAHA prevents TGF-β2-induced increases in outflow resistance and regulates the non-Smad pathway of TGF-β signaling in TM and MSC cells.

SGLT1 Knockdown Attenuates Cardiac Fibroblast Activation in Diabetic Cardiac Fibrosis

Background: Cardiac fibroblast (CF) activation is a hallmark feature of cardiac fibrosis in diabetic cardiomyopathy (DCM). Inhibition of the sodium-dependent glucose transporter 1 (SGLT1) attenuates cardiomyocyte apoptosis and delays the development of DCM. However, the role of SGLT1 in CF activation remains unclear.

Methods: A rat model of DCM was established and treated with si‐SGLT1 to examine cardiac fibrosis. In addition, in vitro experiments were conducted to verify the regulatory role of SGLT1 in proliferation and collagen secretion in high-glucose– (HG–) treated CFs.

Results: SGLT1 was found to be upregulated in diabetic cardiac tissues and HG-induced CFs. HG stimulation resulted in increased proliferation and migration, increased the expression of transforming growth factor-β1 and collagen I and collagen III, and increased phosphorylation of p38 mitogen-activated protein kinase and extracellular signal-regulated kinase (ERK) 1/2. These trends in HG-treated CFs were significantly reversed by si-SGLT1. Moreover, the overexpression of SGLT1 promoted CF proliferation and collagen synthesis and increased phosphorylation of p38 mitogen-activated protein kinase and ERK1/2. SGLT1 silencing significantly alleviated cardiac fibrosis, but had no effect on cardiac hypertrophy in diabetic hearts.

Conclusion: These findings provide new information on the role of SGLT1 in CF activation, suggesting a novel therapeutic strategy for the treatment of DCM fibrosis.

Taohong siwu decoction attenuates myocardial fibrosis by inhibiting fibrosis proliferation and collagen deposition via TGFBR1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Myocardial fibrosis after myocardial infarction (MI) leads to cardiac remodeling and loss of function. Taohong siwu decoction (THSWD), a well-known traditional Chinese medicinal prescription, has been clinically used to treat various cardiovascular and cerebrovascular diseases, but its potential functions in myocardial fibrosis after MI remain uncharacterized.

AIM OF THE STUDY

The purpose of current study was to explore the potential mechanism action and anti-myocardial fibrosis effects of treatment with THSWD in vivo and in vitro.

MATERIALS AND METHODS

Mouse underwent ligation of coronary artery to induce MI and divided equally into the sham group, model group and THSWD treatment groups. After 4 weeks, the effects of THSWD treatment on cardiac function were estimated by echocardiography. HE staining was used to detect the pathologic changes and Masson trichrome staining was used to estimate tissue fibrosis. To further explore the regulatory molecular mechanisms of THSWD, transcriptome analysis was performed. Furthermore, in vitro, we investigated the effect of THSWD on cell proliferation and collagen deposition in primary cardiac fibrosis cells and its possible mechanism of action. Overexpression of TGFBR1 was achieved by infection with an adenovirus vector encoding TGFBR1.

RESULTS

Treatment with THSWD significantly decreased myocardial fibrosis and recovered cardiac function in the post-MI mouse. The transcriptomics data imply that the TGF-β pathway might be a target in the anti-fibrosis effect of THSWD. THSWD inhibits TGF-β1-induced proliferation of primary cardiac fibroblasts. THSWD decreased collagen expression and TGFBR1 and Smad2/3 phosphorylation. Moreover, the inhibitory effect of THSWD on CFs proliferation and collagen deposition, as well as TGFBR1 signaling pathway-associated proteins expression was partially abrogated by overexpression of TGFBR1.

CONCLUSION

Collectively, the results implicate that THSWD attenuates myocardial fibrosis by inhibiting fibrosis proliferation and collagen deposition via inhibiting TGFBR1, and might be a potential therapeutic agent for treatment of myocardial fibrosis post-MI.

Kanglexin protects against cardiac fibrosis and dysfunction in mice by TGF-β1/ERK1/2 noncanonical pathway

Cardiac fibrosis is a common pathological manifestation accompanied by various heart diseases, and antifibrotic therapy is an effective strategy to prevent diverse pathological processes of the cardiovascular system. We currently report the pharmacological evaluation of a novel anthraquinone compound (1,8-dihydroxy-6-methyl-9,10-anthraquinone-3-oxy ethyl succinate) named Kanglexin (KLX), as a potent cardioprotective agent with antifibrosis activity. Our results demonstrated that the administration of KLX by intragastric gavage alleviated cardiac dysfunction, hypertrophy, and fibrosis induced by transverse aortic constriction (TAC) surgical operation. Meanwhile, KLX administration relieved endothelial to mesenchymal transition of TAC mice. In TGF β1-treated primary cultured adult mouse cardiac fibroblasts (CFs) and human umbilical vein endothelial cells (HUVECs), KLX inhibited cell proliferation and collagen secretion. Also, KLX suppressed the transformation of fibroblasts to myofibroblasts in CFs. Further studies revealed that KLX-mediated cardiac protection was due to the inhibitory role of TGF-β1/ERK1/2 noncanonical pathway. In summary, our study indicates that KLX attenuated cardiac fibrosis and dysfunction of TAC mice, providing a potentially effective therapeutic strategy for heart pathological remodeling.

Targeting cardiac fibrosis in heart failure with preserved ejection fraction: mirage or miracle?

Cardiac fibrosis is central to the pathology of heart failure, particularly heart failure with preserved ejection fraction (HFpEF). Irrespective of the underlying profibrotic condition (e.g. ageing, diabetes, hypertension), maladaptive cardiac fibrosis is defined by the transformation of resident fibroblasts to matrix-secreting myofibroblasts. Numerous profibrotic factors have been identified at the molecular level (e.g. TGFβ, IL11, AngII), which activate gene expression programs for myofibroblast activation. A number of existing HF therapies indirectly target fibrotic pathways; however, despite multiple clinical trials in HFpEF, a specific clinically effective antifibrotic therapy remains elusive. Therapeutic inhibition of TGFβ, the master-regulator of fibrosis, has unfortunately proven toxic and ineffective in clinical trials to date, and new approaches are needed. In this review, we discuss the pathophysiology and clinical implications of interstitial fibrosis in HFpEF. We provide an overview of trials targeting fibrosis in HFpEF to date and discuss the promise of potential new therapeutic approaches and targets in the context of underlying molecular mechanisms.

Oxymatrine Inhibits Twist-Mediated Renal Tubulointerstitial Fibrosis by Upregulating Id2 Expression

The final pathway for the development of diabetic nephropathy (DN) into chronic renal failure in DN is glomerulosclerosis and tubulointerstitial fibrosis. Renal tubular lesions can occur in the early stage of DN renal injury. Cumulative evidence shows that oxymatrine (OMT) has a variety of biological and pharmacological properties. In recent years, more attention has been paid on the preventive and therapeutic influence of OMT on organ fibrosis. In this experiment, db/db mice were intraperitoneally injected with OMT 120 mg/kg for 8 weeks, and NRK-52E cultured with 30 mmol/L glucose and 0.1 mg/mL OMT for 48-hour. We investigated the relationship between Id2 and Twist in NRK-52E cells and the effect of OMT on the expression of E-cadherin, α-SMA, Fibronectin, and Collagen-IV by Western blot, Real-time PCR, Immunofluorescence, cell transfection, Co-Immunoprecipitation, and Luciferase assays. OMT increased the expression of Id2 but decreased that of Twist under high glucose condition in vitro and in vivo. The promoted recovery of Id2 facilitated its binding to Twist and affected E-cadherin activity inhibiting EMT and the excessive proliferation and abnormal deposition of ECM. In brief, OMT promotes Id2 to reverse EMT and exert anti-fibrotic effect in diabetic renal tubular epithelial cells by binding Id2 to Twist and affecting its transcriptional activation of downstream target genes. Or findings provide a new experimental basis for delaying the progress and for treatment of diabetic renal fibrosis.

miR‑217‑5p regulates myogenesis in skeletal muscle stem cells by targeting FGFR2

MicroRNA-217-5p (miR-217-5p) has been implicated in cell proliferation; however, its role in skeletal muscle stem cells (SkMSCs) remains unknown. The present study aimed to explore the roles of miR‑217‑5p in the biological characteristics of SkMSCs. SkMSCs were identified by cell surface markers using flow cytometry. The present study observed that miR‑217‑5p mimics accelerated the proliferation and suppressed the differentiation in SkMSCs. In addition, the results of the present study revealed that fibroblast growth factor receptor 2 (FGFR2) was a target of miR‑217‑5p, as miR‑217‑5p bound directly to the 3'‑untranslated region of FGFR2 mRNA, resulting in increased FGFR2 mRNA and protein levels. In addition, the present study suppressed the expression of FGFR2 in SkMSCs using a selective FGFR inhibitor AZD4547 and detected the efficiency of inhibition by reverse transcription‑quantitative PCR and western blotting. miR‑217‑5p levels were positively associated with FGFR2 expression, which was upregulated and accelerated the proliferation of SkMSCs compared with that of the miR‑NC group. Collectively, these results demonstrated that miR‑217‑5p may act as a myogenesis promoter in SkMSCs by directly targeting FGFR2 and may regulate the myogenesis of these cells.

Sophora alopecuroides L.: An ethnopharmacological, phytochemical, and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Sophora alopecuroides L., which is called Kudouzi in China, is a medicinal plant distributed in Western and Central Asia, especially in China, and has been used for decades to treat fever, bacterial infection, heart disease, rheumatism, and gastrointestinal diseases.

AIM OF THE REVIEW

This review aims to provide up-to-date information on S. alopecuroides, including its botanical characterization, medicinal resources, traditional uses, phytochemistry, pharmacological research, and toxicology, in exploring future therapeutic and scientific potentials.

MATERIALS AND METHODS

The information related to this article was systematically collected from the scientific literature databases including PubMed, Google Scholar, Web of Science, Science Direct, Springer, China National Knowledge Infrastructure, published books, PhD and MS dissertations, and other web sources, such as the official website of Flora of China and Yao Zhi website (https://db.yaozh.com/).

RESULTS

A total of 128 compounds, such as alkaloids, flavonoids, steroids, and polysaccharides, were isolated from S. alopecuroides. Among these compounds, the effects of alkaloids, such as matrine and oxymatrine, were extensively studied and developed into new drugs. S. alopecuroides and its active components had a wide range of pharmacological activities, such as anticancer, antiviral, anti-inflammatory, antimicrobial, analgesic, and neuroprotective functions, as well as protective properties against pulmonary fibrosis and cardiac fibroblast proliferation.

CONCLUSIONS

As an important traditional Chinese medicine, modern pharmacological studies have demonstrated that S. alopecuroides has prominent bioactivities, especially on gynecological inflammation and hepatitis B, and anticancer activities. These activities provide prospects for novel drug development for cancer and some chronic diseases. Nevertheless, the comprehensive evaluation, quality control, understanding of the multitarget network pharmacology, long-term in vivo toxicity, and clinical efficacy of S. alopecuroides require further detailed research.

The Expression of BNP, ET-1, and TGF-β1 in Myocardium of Rats with Ventricular Arrhythmias

Ventricular arrhythmia (VA) is a major component of sudden cardiac death (SCD). To investigate the expression of brain natriuretic peptide (BNP), endothelin-1 (ET-1), and transforming growth factor-beta 1 (TGF-β1) during VA, we established a rat model of VA induced by BaCl₂ solution through a microinjector pump. PD142893 (ET-1 receptor blocker) and SB431542 (TGF-β1 receptor type I blocker) were used to explore the effect of ET-1 and TGF-β1 on BNP expression in the myocardium after VA. BNP, ET-1, and TGF-β1 in rat myocardium were assayed by western blot and immunohistochemical staining for proteins, and real-time quantitative polymerase chain reaction for mRNAs. We found increased expression of BNP and ET-1 in rat myocardium that was associated with the duration of VA. However, TGF-β1 protein expression remained unchanged. Such early increases in BNP and ET-1 may be attributed to fatal arrhythmias associated with SCD, suggesting these may be novel biomarkers of this disease. After intraperitoneal injection of PD142893 and SB431542, respectively, BNP was downregulated in the myocardium of the left ventricle; however, this was abrogated by co-application of the two inhibitors. These results suggested that both ET-1 and TGF-β1, by specifically binding to their receptors, might be involved in the myocardial synthesis of BNP during VA in vivo.

N‑acetyl cysteine inhibits lipopolysaccharide‑induced apoptosis of human umbilical vein endothelial cells via the p38MAPK signaling pathway

Lipopolysaccharide (LPS) can regulate the expression of apoptotic factors, including caspase‑3, Bcl‑2 and Bcl‑2‑associated X protein (Bax). Nitric oxide (NO) plays an important role in apoptosis. N‑acetyl cysteine (NAC) has been shown to exhibit antioxidant effects in vitro. However, the effects of NAC on LPS‑induced apoptosis of human umbilical vein endothelial cells (HUVECs) and the associated mechanisms are not well characterized. The present study explored the effect of NAC on LPS‑induced apoptosis of HUVECs and determined the participation of the p38 mitogen‑activated protein kinase (MAPK) pathway in the process of apoptosis. Cell viability was assessed using the Cell Counting Kit‑8 (CCK‑8) assay. The expression of caspase‑3, Bax, Bcl‑2, phosphorylated (p)‑p38MAPK/total (t‑)p38MAPK and p‑endothelial e nitric oxide synthase (eNOS)/t‑eNOS proteins were determined by western blotting. The expression levels of caspase‑3, Bax and Bcl‑2 mRNA were determined using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). The rate of apoptosis was determined using flow cytometry. An NO detection kit (nitric reductase method) was used to determine NO concentration. The results of CCK‑8 and flow cytometric analyses showed that pretreatment of HUVECs with NAC or p38MAPK inhibitor (SB203580) attenuated LPS‑induced decrease in cell viability and increase in cell apoptosis. RT‑qPCR and western blotting showed that LPS promoted caspase‑3 and Bax expression, but inhibited that of Bcl‑2 in HUVECs; however, these effects were attenuated by pretreatment with NAC or SB203580. LPS stimulation significantly enhanced the expression of p‑p38MAPK protein and reduced the expression of p‑eNOS protein; however, these effects were attenuated by pretreatment with NAC or SB203580. NAC pretreatment attenuated LPS‑induced inhibition of NO synthesis, which was consistent with the effects of SB203580. The results demonstrated that NAC pretreatment alleviated LPS‑induced apoptosis and inhibition of NO production in HUVECs. Furthermore, these effects were proposed to be mediated via the p38MAPK signaling pathway.

Inhibitory Effects of Oxymatrine on Transdifferentiation of Neonatal Rat Cardiac Fibroblasts to Myofibroblasts Induced by Aldosterone via Keap1/Nrf2 Signaling Pathways In Vitro

Background

Oxymatrine (OMT), a quinolizidine alkaloid derived from the traditional Chinese herb Radix Sophorae flavescentis, has widely reported pharmacological efficacy in treating cardiovascular dysfunction-related diseases. However, the underlying mechanism has been unclear. Here, we investigated the potential inhibitory effects and mechanism of OMT on transdifferentiation of cardiac fibroblast to myofibroblasts induced by aldosterone in vitro.

Material/Methods

The cardiac fibroblasts (CFBs) proliferation and migration capacity were evaluated by MTT assay, cell cycle assay, and scratch analysis, respectively. The protein expression of the Nrf2/Keap1 signal pathway, FN, Collagen I, Collagen III, α-SMA, CTGF, and mineralocorticoid receptor (MR) protein was detected by Western blot analysis. The mRNA expression of Nrf2 was detected by qRT-PCR. Immunofluorescence staining was used to observe the expression of α-SMA protein. Nrf2 siRNA was used to explore the role of Nrf2 in OMT-treated CFBs. GSH, SOD, and MDA levels and hydroxyproline content were measured by colorimetric assay with commercial kits. The DCFH-DA fluorescent probe was used to assess cellular ROS levels.

Results

OMT and Curcumin (an Nrf2 agonist) attenuated aldosterone (ALD)-induced proliferation and migration in CFBs, as well as the fibrosis-associated protein expression levels. Moreover, OMT activated Nrf2 and promoted the nucleus translocation of Nrf2. OMT alleviated the elevated levels of α-SMA, Collagen I, Collagen III, and CTGF, which were abrogated by the Nrf2 siRNA transfection. We also found that OMT decreased oxidative stress levels.

Conclusions

Our results confirm that OMT alleviates transdifferentiation of cardiac fibroblasts to myofibroblasts induced by aldosterone via activating the Nrf2/Keap1 pathway in vitro.

The role of high fat diet in the regulation of MAP kinases activity in left ventricular fibrosis

It is well known that obesity contributes to the development of systemic inflammatory responses, which in turn may be involved in the process of interstitial fibrosis and left ventricular (LV) remodelling. Activation of pro-inflammatory factors such as transforming growth factor β (TGF-β) can directly stimulate mitogen-activated protein kinase (MAPK) p38 and JNK. The aim of the study was to evaluate the level of TGF-β and MAPK p38 and JNK in the LV in Sprague Dawley (SPRD) rats maintained on a high fat diet (HFD). The SPRD rats from 4 weeks of age were on a normal fat diet (NFD) or a HFD for 12 weeks (NFD-16-week-old rats, NFD 16-wk; or HFD-16-week-old rats, HFD 16-wk) or 16 weeks (NFD-20-week-old rats, NFD 20-wk; or HFD-20-week-old rats, HFD 20-wk). At the end of the experiment, blood and LV were collected from all rats for further analysis (biochemical, Real Time PCR and immunohistochemical analysis). TGF-β mRNA expression did not differ between the study groups of rats. However, p38 MAPK mRNA expression was significantly lower in the HFD 20-wk rats than in both the HFD 16-wk rats and the NFD 20-wk rats. c-jun mRNA expression was significantly higher in the HFD 16-wk rats than in the NFD 16-wk rats. There was significantly lower expression of c-jun mRNA in the HFD 20-wk rats and in the NFD 20-wk rats than in the HFD 16-wk rats and in the NFD 16-wk rats, respectively. TGF-β type II receptor (TβRII) protein demonstrated only cytoplasmic reactivity, while p38 MAPK protein and c-jun protein showed both nuclear and cytoplasmic reactivity. The results suggest that a high fat diet and in two time intervals significantly influence the expression of p38 MAPK and JNK in the LV. However, demonstrating their potential involvement in the processes of interstitial myocardial fibrosis and left ventricular remodeling requires further research.

MicroRNA-143-3p promotes human cardiac fibrosis via targeting sprouty3 after myocardial infarction

Myocardial infarction (MI) is one of the most catastrophic diseases threatening human health in the world. Because cardiomyocytes have a minuscule regenerative potential, the natural repair of infarct healing after MI shows fibrotic scar. MicroRNA-143-3p (miR-143-3p) plays a critical regulatory role in various pathophysiological processes in the heart. Sprouty3 (SPRY3) is predicted to be a potential fibrosis-associated target gene of miR-143-3p. The aim was to explore the role and mechanism of miR-143-3p in the infarct healing after MI in vivo and in vitro. Myocardial samples were obtained during autopsy from 12 human patients with or without MI. An increase in miR-143-3p mRNA levels was detected in the infarct zone of human MI samples. Moreover, silencing expression of miR-143-3p by antagomir-143-3p alleviated fibrotic scar in MI model of mice. To assess the mechanism by which miR-143-3p may function in fibrosis, human cardiac fibroblasts (HCFs) were transfected with miR-143-3p mimics and inhibitors. MiR-143-3p overexpression promoted HCFs proliferation, migration, transformation, and extracellular matrix (ECM) excessive accumulation. Additionally, miR-143-3p inhibitors reversed the fibrosis effect of HCFs treated with transforming growth β1 (TGFβ1) in vitro. Importantly, a luciferase reporter assay demonstrated that miR-143-3p could directly bind to the 3'-untranslational region (3'-UTR) of SPRY3 mRNA. Lastly, HCFs transfected with SPRY3 siRNA (si-SPRY3) enhanced the activation of the P38, ERK, and JNK pathways in the process of fibrosis. MiR-143-3p promoted fibrosis along with SPRY3 degradation and the activation of its downstream P38, ERK, and JNK pathways. Our results may contribute to improve the quality of life in MI patients by interfering with the role of miR-143-3p in MI area.