Dihydrolycorine Attenuates Cardiac Fibrosis and Dysfunction by Downregulating Runx1 following Myocardial Infarction.

In spite of early interventions to treat acute myocardial infarction (MI), the occurrence of adverse cardiac remodeling following heart failure due to acute MI remains a clinical challenge. Thus, there is an increasing demand for the development of novel therapeutic agents capable of inhibiting the development of pathological ventricular remodeling. RNA-seq data analysis of acute MI rat models from GEO revealed that Runx1 was the most differentially expressed MI-related gene. In this study, we demonstrated that increased Runx1 expression under pathological conditions results in decreased cardiac contractile function. We identified dihydrolycorine, an alkaloid lycorine, as a promising inhibitor of Runx1. Our results showed that treatment with this drug could prevent adverse cardiac remodeling, as indicated by the downregulation of fibrotic genes using western blotting (collagen I, TGFß, and p-smad3), downregulation of the apoptosis gene Bax, upregulation of the apoptosis gene Bcl-2, and improved cardiac functions, such as LVEF, LVSF, LVESD, and LVEDD. Additionally, dihydrolycorine treatment could rescue cardiomyocyte hypertrophy as demonstrated by wheat germ agglutinin staining, increased expression levels of the punctuate gap junction protein connexin 43, and decreased α-SMA expression, resulting in cardiomyocyte fibrosis in immunofluorescence staining. Molecular docking, binding modeling, and pull-down assays were used to identify potential dihydrolycorine-binding sites in Runx1. When Ad-sh-Runx1 was transfected into hypoxia-cardiomyocytes or injected into the hearts of MI rats, the cardioprotective effects of dihydrolycorine were abolished, and the normal electrophysiological activity of cardiomyocytes was disrupted. Taken together, the results of the present study indicate that dihydrolycorine may inhibit adverse cardiac remodeling after MI through the reduction of Runx1, suggesting that dihydrolycorine-mediated-Runx1 regulation might represent a novel therapeutic approach for adverse cardiac remodeling after MI.

Inhibition of the long non-coding RNA ZFAS1 attenuates ferroptosis by sponging miR-150-5p and activates CCND2 against diabetic cardiomyopathy.

Diabetic cardiomyopathy (DbCM) is responsible for increased morbidity and mortality in patients with diabetes and heart failure. However, the pathogenesis of DbCM has not yet been identified. Here, we investigated the important role of lncRNA-ZFAS1 in the pathological process of DbCM, which is associated with ferroptosis. Microarray data analysis of DbCM in patients or mouse models from GEO revealed the significance of ZFAS1 and the significant downregulation of miR-150-5p and CCND2. Briefly, DbCM was established in high glucose (HG)-treated cardiomyocytes and db/db mice to form in vitro and in vivo models. Ad-ZFAS1, Ad-sh-ZFAS1, mimic miR-150-5p, Ad-CCND2 and Ad-sh-CCND2 were intracoronarily administered to the mouse model or transfected into HG-treated cardiomyocytes to determine whether ZFAS1 regulates miR-150-5p and CCND2 in ferroptosis. The effect of ZFAS1 on the left ventricular myocardial tissues of db/db mice and HG-treated cardiomyocytes, ferroptosis and apoptosis was determined by Masson staining, immunohistochemical staining, Western blotting, monobromobimane staining, immunofluorescence staining and JC-1 staining. The relationships among ZFAS1, miR-150-5p and CCND2 were evaluated using dual-luciferase reporter assays and RNA pull-down assays. Inhibition of ZFAS1 led to reduced collagen deposition, decreased cardiomyocyte apoptosis and ferroptosis, and attenuated DbCM progression. ZFAS1 sponges miR-150-5p to downregulate CCND2 expression. Ad-sh-ZFAS1, miR-150-5p mimic, and Ad-CCND2 transfection attenuated ferroptosis and DbCM development both in vitro and in vivo. However, transfection with Ad-ZFAS1 could reverse the positive effects of miR-150-5p mimic and Ad-CCND2 in vitro and in vivo. lncRNA-ZFAS1 acted as a ceRNA to sponge miR-150-5p and downregulate CCND2 to promote cardiomyocyte ferroptosis and DbCM development. Thus, ZFAS1 inhibition could be a promising therapeutic target for the treatment and prevention of DbCM.

Herpud1 deficiency could reduce amyloid-ß40 expression and thereby suppress homocysteine-induced atherosclerosis by blocking the JNK/AP1 pathway.

Homocysteine (Hcy) is considered an independent risk factor for various cardiovascular diseases including atherosclerosis which is associated with lipid metabolism, inflammation, and oxidative stress. Results from our previous study suggested that Hcy-induced atherosclerosis could be reversed by Herpud1 knockout which inhibits vascular smooth muscle cell (VSMC) phenotype switching. Here, we aim to investigate more precise mechanisms behind the improvement in Hcy-induced atherosclerosis. Amyloid-ß40 (Aß40), a vital protein in Alzheimer disease (AD), has been regarded as an important component in the atherosclerosis program in recent years due to the biological similarity between AD and atherosclerosis. Thus, we determined to assess the value of Aß40 in a Herpud1 knockout Hcy-induced atherosclerosis mouse model by measuring Aß40 expression in tissue and biomarkers of lipid metabolism, inflammation, and oxidative stress in serum. Additionally, since endothelial dysfunction plays a prominent role in atherosclerosis, we tested human umbilical vein endothelial cell (HUVEC) function following Herpud1 silencing in vitro and evaluated JNK/AP1 signaling activation in our models because of its close relationship with Aß40. As a result, our animal models showed that Herpud1 knockout reduced Aß40 expression, inflammation, and oxidative stress levels other than lipid metabolism and alleviated atherosclerosis via JNK/AP1 signaling inhibition. Similarly, our cell experiments implied that Hcy-induced Aß40 elevation and HUVEC dysfunction involving cell proliferation and apoptosis could be restored by Herpud1 silence through restraining JNK/AP1 pathway. Collectively, our study demonstrates that Herpud1 deficiency could reduce Aß40 expression, thereby suppressing Hcy-induced atherosclerosis by blocking the JNK/AP1 pathway. This may provide novel potential targets for atherosclerosis prevention or treatment.

Icariin Ameliorates Diabetic Cardiomyopathy Through Apelin/Sirt3 Signalling to Improve Mitochondrial Dysfunction.

Myocardial contractile dysfunction in diabetic cardiomyocytes is a significant promoter of heart failure. Herein, we investigated the effect of icariin, a flavonoid monomer isolated from Epimedium, on diabetic cardiomyopathy (DCM) and explored the mechanisms underlying its unique pharmacological cardioprotective functions. High glucose (HG) conditions were simulated in vitro using cardiomyocytes isolated from neonatal C57 mice, while DCM was stimulated in vivo in db/db mice. Mice and cardiomyocytes were treated with icariin, with or without overexpression or silencing of Apelin and Sirt3 via transfection with adenoviral vectors (Ad-RNA) and specific small hairpin RNAs (Ad-sh-RNA), respectively. Icariin markedly improved mitochondrial function both in vivo and in vitro, as evidenced by an increased level of mitochondrial-related proteins via western blot analysis (PGC-1α, Mfn2, and Cyt-b) and an increased mitochondrial membrane potential, as observed via JC-1 staining. Further, icariin treatment decreased cardiac fibrogenesis (Masson staining), and inhibited apoptosis (TUNEL staining). Together, these changes improved cardiac function, according to multiple transthoracic echocardiography parameters, including LVEF, LVSF, LVESD, and LVEDD. Moreover, icariin significantly activated Apelin and Sirt3, which were inhibited by HG and DCM. Importantly, when Ad-sh-Apelin and Ad-sh-Sirt3 were transfected in cardiomyocytes or injected into the heart of db/db mice, the cardioprotective effects of icariin were abolished and mitochondrial homeostasis was disrupted. Further, it was postulated that since Ad-Apelin induced different results following increased Sirt3 expression, icariin may have attenuated DCM development by preventing mitochondrial dysfunction through the Apelin/Sirt3 pathway. Hence, protection against mitochondrial dysfunction using icariin may prove to be a promising therapeutic strategy against DCM in diabetes.

Dihydromyricetin Prevents Diabetic Cardiomyopathy via miR-34a Suppression by Activating Autophagy.

PURPOSE: The pro-aging miRNA, miR-34a, is hyperactivated in the cardiac myocardial tissues of patients and mice with diabetes, leading to diabetic cardiomyopathy (DCM). Increasing evidence suggests that dihydromyricetin (DHM) can be used to effectively treat cardiomyopathy. In this study, we investigated whether DHM affects the expression of miR-34a in DCM. METHODS: The expression of miR-34a in high-glucose-induced cardiomyocytes and in the heart tissue of diabetic mice was determined by microRNA isolation and quantitative reverse transcription-polymerase chain reaction. Lipofectamine 3000 was used to transfect cardiomyocytes with miR-34a inhibitor, miR-34a mimics, and miR-control. These agents were intravenously injected into the tail vein of streptozotocin-induced diabetic mice. Autophagy and apoptosis were assessed in high-glucose-induced cardiomyocytes and cardiac tissue in diabetic mice by western blotting, immunofluorescence, Masson staining, hematoxylin and eosin staining (H&E), and electron microscopy. RESULTS: DHM clearly ameliorated the cardiac dysfunction in the diabetic mice. The expression of miR-34a was up-regulated in high-glucose-induced cardiomyocytes and in the hearts of diabetic mice, thus impairing autophagy. Treatment with DHM decreased the expression of miR-34a and rescued the impairment of autophagy in high-glucose-induced cardiomyocytes and in the heart tissue of diabetic mice, while the miR-34a mimic offset the effect of DHM with respect to the development of DCM by inhibiting autophagy. CONCLUSIONS: By decreasing the expression of miR-34a, DHM restores impaired autophagy, and thus ameliorates DCM. Therefore, DHM may potentially be used in the treatment of DCM.

Dihydromyricetin alleviates doxorubicin-induced cardiotoxicity by inhibiting NLRP3 inflammasome through activation of SIRT1.

Doxorubicin (DOX) is a powerful anthracycline antineoplastic drug whose clinical application is limited by serious cardiotoxic side effects. Dihydromyricetin (DHM), a flavonoid compound extracted from the Japanese raisin tree (Hovenia dulcis), is cardioprotective in patients with heart failure; however, the underlying mechanisms are poorly understood. The aim of this study was to assess the possible anti-inflammatory properties of DHM in a rat model of DOX-induced cardiotoxicity and DOX-treated H9C2 cells, and gain insights into the molecular mechanisms that mediate these effects. The results showed that DHM treatment significantly improved the myocardial structure and function in DOX-exposed rats by alleviating NLRP3 inflammasome-mediated inflammation. DHM also inhibited DOX-induced activation of the NLRP3 inflammasome in H9C2 cells. This effect was mediated by inhibition of caspase-1 activity, suppression of IL-1ß and IL-18 release, and upregulation of SIRT1 protein levels in vivo and in vitro. Moreover, selective inhibition of SIRT1 blocked the protective effects of DHM. Collectively, our findings indicate that DHM protects against DOX-induced cardiotoxicity by inhibiting NLRP3 inflammasome activation via stimulation of the SIRT1 pathway.

Linc-ROR targets FGF2 to regulate HASMC proliferation and migration via sponging miR-195-5p.

Atherosclerosis is a common cardiovascular disorder and is characterized by damage of endothelial cells, cell inflammation, hyper-proliferation of vascular smooth muscle cells and the accumulation of extracellular lipids and fibrous tissues. In this study, we firstly examined the expression level of long intergenic non-protein coding RNA, regulator of reprogramming (linc-ROR) in homocysteine (Hcy)-stimulated human aortic smooth muscle cells (HASMCs), and then looked into the potential molecular signaling axis of linc-ROR in regulating the proliferation and migration of HASMCs. Hcy promoted HASMC proliferation and up-regulated linc-ROR expression. Functional studies showed that linc-ROR exerted enhanced actions on the proliferation and migration of HASMCs. In addition, linc-ROR acted as a competing endogenous RNA for miR-195-5p and repressed the miR-195-5p expression in HASMCs. Linc-ROR was up-regulated the miR-195-3p was down-regulated in the plasma from CAD patients when compared to normal controls. Furthermore, fibroblast growth factor 2 (FGF2) was identified as a target of miR-195-5p and was negatively regulated by miR-195-5p in HASMCs. The rescue experiments revealed that linc-ROR-mediated HASMC proliferation and migration may be via regulating miR-195-5p/FGF2 axis. Linc-ROR inhibition blocked the miR-195-5p/FGF2 signaling in Hcy-treated HASMCs, and this effect may also involve in the miR-195-5p/FGF2 axis. To summarize, the data of the present study identified the up-regulation of linc-ROR in Hcy-stimulated HASMCs, and further mechanistic functional studies revealed that linc-ROR promoted HASMC proliferation and migration via regulating miR-195-5p/FGF2 axis. The present study provided the novel actions of linc-ROR in regulating HASMC proliferation and migration, which may be related to the pathophysiology of atherosclerosis.

Doxorubicin induces cardiomyocyte pyroptosis via the TINCR-mediated posttranscriptional stabilization of NLR family pyrin domain containing 3.

AIMS: Doxorubicin (DOX), a widely used powerful chemotherapeutic component for cancer treatment, can give rise to severe cardiotoxicity that limits its clinical use. Pyroptosis is characterized by proinflammation and has been defined as a new type of programmed cell death in recent years. However, whether the DOX-induced cardiotoxicity is related to pyroptosis, and if so, which genes are involved in this process is largely unknown. In this study, we sought to identify the effect of DOX on cardiomyocyte pyroptosis and further reveal the underlying regulatory mechanism. METHODS AND RESULTS: In vitro and in vivo experiments showed that DOX treatment induced cardiomyocyte pyroptosis as evidenced by increased cell death and upregulated expression levels of NLR family pyrin domain containing 3 (NLRP3), caspase-3, IL-1ß, IL-18 and GMDSD-N. Inhibition of NLRP3 rescued the DOX-induced pyroptosis. qRT-PCR showed that TINCR lncRNA was upregulated by DOX treatment and knockdown of TINCR reversed the DOX-induced pyroptosis both in vitro and in vivo. Mechanistic investigations revealed that TINCR increased NLRP3 level via recruiting IGF2BP1 to enhance NLRP3 mRNA. And the effect of TINCR on cardiomyocyte pyroptosis was attenuated by the inhibition of NLRP3 or IGF2BP1. Finally, TINCR was not involved in DOX-induced pyroptosis in cancer cells. CONCLUSION: TINCR mediates the DOX-induced cardiotoxicity and pyroptosis in an IGF2BP1-dependent manner. Therefore, TINCR may serve as a promising therapeutic target to overcome the cardiotoxicity of chemotherapy for cancer therapy.

Linc-POU3F3 is overexpressed in in-stent restenosis patients and induces VSMC phenotypic transformation via POU3F3/miR-449a/KLF4 signaling pathway.

BACKGROUND: With the extensive application of stent implantation in patients undergoing percutaneous coronary interventions (PCI), there are chances that in-stent restenosis (ISR)-a major vascular complication caused by vascular smooth muscle cell (VSMC) phenotypic transformation-might occur. OBJECTIVES: This study sought to evaluate the role of lincRNA-POU3F3 on VSMC phenotypic transformation and the underlying mechanism. METHODS: VSMCs were used in our research. We first constructed a gene delivery system through an assembly of lipofectamine and a functional plasmid DNA (pDNA) encoding lincRNA-POU3F3 or MicroRNA-449a, and then, transfected it to VSMCs. Moreover, lentivirus-mediated KLF4 inhibitor (KLF4 siRNA) was also used in these cells. Expression of relevant proteins, such as smooth muscle myosin heavy chain (SM-MHC), alpha smooth muscle actin (α-SMA), osteopontin (OPN), and kruppel-like factor 4 (KLF4), was examined by western blot or immunofluorescence (IF) assay. CCK-8 and wound healing assays were performed to assess the growth and migration of VSMCs. qRT-PCR was used to assess linc-POU3F3 and miR-449a levels. Luciferase reporter assay was also performed. RESULTS: POU3F3 levels were significantly higher in ISR patients compared to controls. We observed that linc-POU3F3 promoted VSMC proliferation and migration, and induced VSMC phenotypic transformation via POU3F3/miR-449a/KLF4 signaling pathway. CONCLUSION: Linc-POU3F3 promotes phenotypic transformation of VSMCs via POU3F3/miR-449a/KLF4 pathway. It may provide a theoretical basis to attenuate ISR via pharmacological inhibition of this biomarker or at least serve as a predictor of diagnosis or prognosis of patients with restenosis.

Yellow Wine Polyphenolic Compounds prevents Doxorubicin-induced cardiotoxicity through activation of the Nrf2 signalling pathway.

Doxorubicin (DOX) is considered as the major culprit in chemotherapy-induced cardiotoxicity. Yellow wine polyphenolic compounds (YWPC), which are full of polyphenols, have beneficial effects on cardiovascular disease. However, their role in DOX-induced cardiotoxicity is poorly understood. Due to their antioxidant property, we have been suggested that YWPC could prevent DOX-induced cardiotoxicity. In this study, we found that YWPC treatment (30 mg/kg/day) significantly improved DOX-induced cardiac hypertrophy and cardiac dysfunction. YWPC alleviated DOX-induced increase in oxidative stress levels, reduction in endogenous antioxidant enzyme activities and inflammatory response. Besides, administration of YWPC could prevent DOX-induced mitochondria-mediated cardiac apoptosis. Mechanistically, we found that YWPC attenuated DOX-induced reactive oxygen species (ROS) and down-regulation of transforming growth factor beta 1 (TGF-ß1)/smad3 pathway by promoting nuclear factor (erythroid-derived 2)-like 2 (Nrf2) nucleus translocation in cultured H9C2 cardiomyocytes. Additionally, YWPC against DOX-induced TGF-ß1 up-regulation were abolished by Nrf2 knockdown. Further studies revealed that YWPC could inhibit DOX-induced cardiac fibrosis through inhibiting TGF-ß/smad3-mediated ECM synthesis. Collectively, our results revealed that YWPC might be effective in mitigating DOX-induced cardiotoxicity by Nrf2-dependent down-regulation of the TGF-ß/smad3 pathway.

Impaired autophagy mediates hyperhomocysteinemia-induced HA-VSMC phenotypic switching.

Hyperhomocysteinemia (HHcy) is a highly-related risk factor in vascular smooth muscle cell (VSMC) phenotypic modulation and atherosclerosis. Growing evidence indicated that autophagy is involved in pathological arterial changes. However, the risk mechanisms by which homocysteine and VSMC autophagy interact with cardiovascular disease are poorly understood. This study verified the homocysteine-responsive endoplasmic reticulum protein promotion of VSMC phenotypic switching, and the formation of atherosclerotic plaque in vitro. We found that impaired autophagy, as evidenced by decreased levels of MAP1LC3B II/MAP1LC3B I, has a vital role in HHcy-induced human aortic (HA)-VSMC phenotypic switching, with a decrease in contractile proteins (SM α-actin and calponin) and an increase in osteopontin. Knockdown of the essential autophagy gene Atg7 by small interfering RNA promoted HA-VSMC phenotypic switching, indicating that impaired autophagy induces phenotypic switching in these cells. HHcy co-treatment with rapamycin triggered autophagy, which alleviated HA-VSMC phenotypic switching. Finally, we found that Krüppel-like factor 4 (KLF4), a zinc-finger transcription factor for maintaining genomic stability by resisting oxidative stress and restoring autophagy, is closely involved in this process. HHcy clearly decreased KLF4 expression. KLF4-specific siRNA aggravated defective autophagy and phenotypic switching. Mechanistically, KLF4 regulated the HHcy-induced decrease in HA-VSMC autophagy via the m-TOR signaling pathway. In conclusion, these results demonstrated that the KLF4-dependent rapamycin signaling pathway is a novel mechanism underlying HA-VSMC phenotypic switching and is crucial for HHcy-induced HA-VSMCs with defective autophagy to accelerate early atherosclerosis.

The Role of Tauroursodeoxycholic Acid on Dedifferentiation of Vascular Smooth Muscle Cells by Modulation of Endoplasmic Reticulum Stress and as an Oral Drug Inhibiting In-Stent Restenosis.

PURPOSE: The role of endoplasmic reticulum (ER) stress in cardiovascular disease is now recognized. Tauroursodeoxycholic acid (TUDCA) is known to have cardiovascular protective effects by decreasing ER stress. This study aimed to assess the ability of TUDCA to decrease ER stress, inhibit dedifferentiation of vascular smooth muscle cells (VSMCs), and reduce in-stent restenosis. METHODS: The effect of TUDCA on dedifferentiation of VSMCs and ER stress was investigated in vitro using wound-healing assays, MTT assays, and western blotting. For in vivo studies, 18 rabbits were fed an atherogenic diet to induce atheroma formation. Bare metal stents (BMS), BMS+TUDCA or Firebird stents were implanted in the left common carotid artery. Rabbits were euthanized after 28 days and processed for scanning electron microscope (SEM), histological examination (HE), and immunohistochemistry. RESULTS: In vitro TUDCA (10-1000 µmol/L) treatment significantly inhibited platelet-derived growth factor (PDGF)-BB-induced proliferation and migration in VSMCs in a concentration-dependent manner and decreased ER stress markers (IRE1, XBP1, KLF4, and GRP78). In vivo, we confirmed no significant difference in neointimal coverage on three stents surfaces; neointimal was significantly lower with BMS+TUDCA (1.6 ± 0.2 mm2) compared with Firebird (1.90 ± 0.1 mm2) and BMS (2.3 ± 0.1 mm2). Percent stenosis was lowest for BMS+TUDCA, then Firebird, and was significantly higher with BMS (28 ± 4%, 35 ± 7%, 40 ± 1%; respectively; P < 0.001). TUDCA treatment decreased ER stress in the BMS+TUDCA group compared with BMS. CONCLUSIONS: TUDCA inhibited dedifferentiation of VSMCs by decreasing ER stress and reduced in-stent restenosis, possibly through downregulation of the IRE1/XBP1 signaling pathway.

Knockdown of Herp alleviates hyperhomocysteinemia mediated atherosclerosis through the inhibition of vascular smooth muscle cell phenotype switching.

BACKGROUND: Phenotypic switching of vascular smooth muscle cells (VSMCs) plays a key role in atherosclerosis. We aimed to investigate whether Homocysteine-responsive endoplasmic reticulum protein (Herp) was involved in VSMC phenotypic switching and affected atheroprogression. METHODS: To assess the role of Herp in homocysteine (Hcy)-associated atherosclerosis, Herp-/- and LDLR-/- double knockout mice were generated and fed with a high methionine diet (HMD) to induce Hyperhomocysteinemia (HHcy). Atherosclerotic lesions, cholesterol homeostasis, endoplasmic reticulum (ER) stress activation, and the phenotype of VSMCs were assessed in vivo. We used siRNAs to knockdown Herp in cultured VSMCs to further validate our findings in vitro. RESULTS: HMD significantly activated the activating transcription factor 6 (ATF6)/Herp arm of ER stress in LDLR-/- mice, and induced the phenotypic switch of VSMCs, with the loss of contractile proteins (SMA and calponin) and an increase of OPN protein. Herp-/-/LDLR-/- mice developed reduced atherosclerotic lesions in the aortic sinus and the whole aorta when compared with LDLR-/- mice. However, Herp deficiency had no effect on diet-induced HHcy and hyperlipidemia. Inhibition of VSMC phenotypic switching, decreased proliferation and collagen accumulation were observed in Herp-/-/LDLR-/- mice when compared with LDLR-/- mice. In vitro experiments demonstrated that Hcy caused VSMC phenotypic switching, promoted cell proliferation and migration; this was reversed by Herp depletion. We achieved similar results via inhibition of ER stress using 4-phenylbutyric-acid (4-PBA) in Hcy-treated VSMCs. CONCLUSION: Herp deficiency inhibits the phenotypic switch of VSMCs and the development of atherosclerosis, thus providing novel insights into the role of Herp in atherogenesis.