Sepsis, defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, remains a global health challenge characterized by high mortality and limited therapeutic options. Recent evidence identifies ferroptosis—an iron-dependent form of regulated cell death driven by the lethal accumulation of lipid peroxides—as a pivotal mechanism underlying sepsis-induced organ damage. Ferroptosis Suppressor Protein 1 (FSP1) has emerged as a critical endogenous inhibitor of ferroptosis that operates independently of the canonical GPX4/glutathione system. This review provides a comprehensive overview of recent research on FSP1 in the context of sepsis-associated organ injury. We detail the multifaceted molecular mechanisms through which FSP1 inhibits ferroptosis, including the canonical FSP1-CoQ10-NAD(P)H axis, the non-canonical vitamin K cycle, ESCRT-III-mediated membrane repair, and the newly characterized vitamin B2-dependent metabolic stability pathway. Furthermore, we highlight the newly discovered STING-FSP1 signaling axis, where cGAS-STING activation transcriptionally represses FSP1, thereby driving endothelial ferroptosis and vascular leakage during sepsis. Additionally, potentially conserved pathways extrapolated from other acute injury models (e.g., ALKBH5, CD36, and SENP3) are discussed to propose novel research directions. The organ-specific roles and protective mechanisms of FSP1 in sepsis-induced injuries of the lungs, heart, liver, kidneys, and brain are systematically summarized. Finally, we evaluate the prospects and challenges of targeting FSP1-related pathways, such as Nrf2 activation and STING inhibition, as potential therapeutic strategies for sepsis. Overall, This review aims to provide new insights into the “inflammation-cell death” cascade in sepsis and offer a theoretical foundation for developing FSP1-targeted interventions to suppress ferroptosis.

Ferroptosis is a regulated form of cell death that is dependent on reactive oxygen species (ROS) and iron metabolism. Ferroptosis can participate in the formation and rupture of atherosclerotic plaque by regulating apoptosis. However, the mechanism of vascular endothelial cells (VECs) ferroptosis in the occurrence and development of atherosclerosis (AS) requires further exploration. Previous studies have shown that peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) can improve mitochondrial dysfunction and apoptosis induced by oxidized low-density lipoprotein (oxLDL), but its specific role in VECs ferroptosis remains unclear. In this study, we found that oxLDL can induce VECs ferroptosis, and mitochondria are key to oxLDL-induced VECs ferroptosis. As a key regulator of mitochondrial function, the protein expression of PGC-1α was lower in oxLDL-treated VECs. Moreover, overexpression of PGC-1α inhibited oxLDL-induced VECs ferroptosis, whereas the role of PGC-1α was affected by its upstream regulatory molecule AMPK in this process. This study explores the new idea of oxLDL-induced VECs ferroptosis mediated by AMPK/PGC-1α to better understand the pathogenesis of vascular lesions caused by high lipid levels and provides a theoretical basis for the early prevention of AS.

BACKGROUND:The impairment of vascular smooth muscle cells (VSMCs) causes many vascular diseases, such as atherosclerosis, hypertension, and heart conditions. Research has shown that N6-methyladenosine (m6A) modification regulates VSMCs' function in a vascular environment. SUMMARY:By regulating RNA metabolism, m6A modification affects key biological processes in VSMCs, such as proliferation, migration, phenotypic transformation, and apoptosis. We aim to examine the role of m6A modification and its associated enzymes in vascular diseases caused by VSMC dysfunction and explore its potential as a therapeutic target so that we can develop drugs targeting VSMC dysfunction on a scientific basis. KEY MESSAGES:m6A modification's role in cardiovascular disorders and potential as a therapeutic target demand further study as a critical regulating component in VSMC biology.

BACKGROUND:Hypoxia-induced pulmonary artery hypertension (HPH) is a complication of chronic hypoxic lung disease and the third most common type of pulmonary artery hypertension (PAH). Epigenetic mechanisms play essential roles in the pathogenesis of HPH. N6-methyladenosine (m6A) is an important modified RNA nucleotide involved in a variety of biological processes and an important regulator of epigenetic processes. To date, the precise role of m6A and regulatory molecules in HPH remains unclear. METHODS:HPH model and pulmonary artery smooth muscle cells (PASMCs) were constructed from which m6A changes were observed and screened for AlkB homolog 5 (Alkbh5). Alkbh5 knock-in (KI) and knock-out (KO) mice were constructed to observe the effects on m6A and evaluate right ventricular systolic pressure (RVSP), left ventricular and septal weight [RV/(LV + S)], and pulmonary vascular remodeling in the context of HPH. Additionally, the effects of Alkbh5 knockdown using adenovirus were examined in vitro on m6A, specifically in PASMCs with regard to proliferation, migration and cytochrome P450 1A1 (Cyp1a1) mRNA stability. RESULTS:In both HPH mice lung tissues and hypoxic PASMCs, a decrease in m6A was observed, accompanied by a significant up-regulation of Alkbh5 expression. Loss of Alkbh5 attenuated the proliferation and migration of hypoxic PASMCs in vitro, with an associated increase in m6A modification. Furthermore, Alkbh5 KO mice exhibited reduced RVSP, RV/(LV + S), and attenuated vascular remodeling in HPH mice. Mechanistically, loss of Alkbh5 inhibited Cyp1a1 mRNA decay and increased its expression through an m6A-dependent post-transcriptional mechanism, which hindered the proliferation and migration of hypoxic PASMCs. CONCLUSION:The current study highlights the loss of Alkbh5 impedes the proliferation and migration of PASMCs by inhibiting post-transcriptional Cyp1a1 mRNA decay in an m6A-dependent manner.

Objective: We here explored whether perinatal nonylphenol (NP) exposure causes myocardial fibrosis (MF) during adulthood in offspring rats and determined the role of the TGF-β1/LIMK1 signaling pathway in NP-induced fibrosis in cardiac fibroblasts (CFs). Methods and results: Histopathology revealed increased collagen deposition and altered fiber arrangement in the NP and isoproterenol hydrochloride (ISO) groups compared with the blank group. Systolic and diastolic functions were impaired. Western blotting and qRT-PCR demonstrated that the expression of central myofibrosis-related proteins (collagens Ι and ΙΙΙ, MMP2, MMP9, TGF-β1, α-SMA, IL-1β, and TGF-β1) and genes (Collagen Ι, Collagen ΙΙΙ, TGF-β1, and α-SMA mRNA) was upregulated in the NP and ISO groups compared with the blank group. The mRNA-seq analysis indicated differential expression of TGF-β1 signaling pathway-associated genes and proteins. Fibrosis-related protein and gene expression increased in the CFs stimulated with the recombinant human TGF-β1 and NP, which was consistent with the results of animal experiments. According to the immunofluorescence analysis and western blotting, NP exposure activated the TGF-β1/LIMK1 signaling pathway whose action mechanism in NP-induced CFs was further validated using the LIMK1 inhibitor (BMS-5). The inhibitor modulated the TGF-β1/LIMK1 signaling pathway and suppressed the NP-induced increase in fibrosis-related protein expression in the CFs. Thus, the aforementioned pathway is involved in NP-induced fibrosis. Conclusion: We here provide the first evidence that perinatal NP exposure causes myocardial fibrosis in growing male rat pups and reveal the molecular mechanism and functional role of the TGF-β1/LIMK1 signaling pathway in this process.

BACKGROUND:International studies have shown that use of a subcutaneous implantable cardioverter defibrillator (S-ICD) could reduce lead-related complications while maintaining adequate defibrillation performance; however, data from the Chinese population or other Asian groups are limited. MATERIAL AND METHODS:SCOPE is a prospective, multicenter, observational cohort study. Two hundred patients with primary prevention indication for sudden cardiac death (SCD), who are candidates for S-ICD, will be enrolled. From the same population, another 200 patients who are candidates for transvenous implantable cardioverter defibrillator (TV-ICD) will be enrolled after being matched for age, sex, SCD high-risk etiology (ischemic cardiomyopathy, and non-ischemic cardiomyopathy, ion channel disease, and other) and atrial fibrillation in a 1: 1 ratio with enrolled S-ICD patients. All the patients will be followed for 18 months under standard of care. RESULTS:The primary endpoint is proportion of patients free from inappropriate shock (IAS) at 18 months in the S-ICD group. The lower 95% confidence bound of the proportion will be compared with a performance goal of 90.3%, which was derived from the previous meta-analysis. The comparisons between S-ICD and TV-ICD on IAS, appropriate shock, and complications will be used as secondary endpoints without formal assumptions. CONCLUSIONS:This is the first prospective multicenter study focusing on the long-term performance of S-ICD in a Chinese population. By comparing with the data derived from international historical studies and a matched TV-ICD group, data from SCOPE will allow for the assessment of S-ICD in the Chinese population in a contemporary real-world implantation level and programming techniques, which will help us to further modify the device implantation and programming protocol in this specific population in the future.

Background: In-stent neoatherosclerosis (ISNA) is an important cause of in-stent restenosis (ISR) with drug-eluting stent (DES) implants. High-density lipoprotein cholesterol (HDL-C) is associated with ISNA. However, few studies have focused on the functionalities of HDL-C composition, and till date, optical coherence tomography (OCT) has not been used to analyze the relationship between ISNA incidence and HDL-C-to-apolipoprotein A-I ratio (HAR) in patients with DES implants and ISR (DES-ISR). This study aimed to clarify the association between HAR and ISNA. Methods: This single-center, retrospective study included patients admitted to the Affiliated Hospital of Zunyi Medical University. A total of 216 patients with 220 ISR lesions who underwent OCT for the culprit stent were included between July 2018 and November 2022. Based on HAR at admission, 33rd and 66th percentiles were identified as the cut-off points, and all eligible patients were divided into three groups: Tertile 1 (HAR <= 0.836; n=71), Tertile 2 (0.836< HAR <0.932; n=73), and Tertile 3 (HAR >= 0.932; n=72). Baseline characteristics and angiographic and OCT features were compared between the different groups. In addition, univariate and multivariate logistic regression models were used to assess the association of HAR with ISNA and in-stent thin-cap fibroatheroma (TCFA). Results: Angiographic characteristics and quantitative OCT assessment values did not differ significantly among the groups. The incidences of ISNA (62.0% vs. 52.1% vs. 37.5%, P=0.01) and in-stent TCFA (35.2% vs. 27.4% vs. 15.3%, P=0.02) were significantly lower in the third tertile of the HAR group than in the first or second tertiles. The multifactor logistic regression model revealed that the highest tertile group had a reduced risk of ISNA [hazard ratio (HR) =0.185, 95% confidence interval (CI): 0.081-0.421; P<0.001] and TCFA (HR =0.197, 95% CI: 0.075-0.517; P<0.001) compared with the lowest tertile group. Conclusions: OCT revealed high HAR levels to be negatively correlated with the incidences of ISNA and TCFA in patients with ISR. HAR is a better indicator of ISNA and plaque fragility than HDL-C itself, thus providing a marker and pathway for better prevention of ISNA.

ABSTRACT Cardiac macrophages with different polarization phenotypes regulate ventricular remodeling and neovascularization after myocardial infarction (MI). Annexin A2 (ANXA2) promotes macrophage polarization to the repair phenotype and regulates neovascularization. However, whether ANXA2 plays any role in post-MI remodeling and its underlying mechanism remains obscure. In this study, we observed that expression levels of ANXA2 were dynamically altered in mouse hearts upon MI and peaked on the second day post-MI. Using adeno-associated virus vector–mediated overexpression or silencing of ANXA2 in the heart, we also found that elevation of ANXA2 in the infarcted myocardium significantly improved cardiac function, reduced cardiac fibrosis, and promoted peri-infarct angiogenesis, compared with controls. By contrast, reduction of cardiac ANXA2 exhibited opposite effects. Furthermore, using in vitro coculture system, we found that ANXA2-engineered macrophages promoted cardiac microvascular endothelial cell (CMEC) proliferation, migration, and neovascularization. Mechanistically, we identified that ANXA2 interacted with yes-associated protein (YAP) in macrophages and skewed them toward pro-angiogenic phenotype by inhibiting YAP activity. In addition, ANXA2 directly interacted with integrin β3 in CMECs and enhanced their growth, migration, and tubule formation. Our results indicate that increased expression of ANXA2 could confer protection against MI-induced injury by promoting neovascularization in the infarcted area, partly through the inhibition of YAP in macrophages and activation of integrin β3 in endothelial cells. Our study provides new therapeutic strategies for the treatment of MI injury.

Background: Nonylphenol (NP) is a common environmental endocrine disruptor that is associated with the development of cardiovascular disease. However, the toxic effect of NP on mitochondria in the heart of offspring to exposed individuals remains exclusive. Objective: To investigate whether perinatal NP exposure causes mitochondrial damage in the hearts of offspring of exposed individuals and determine its mechanism of action through both animal and cell experiments. Methods and results: For the in vivo experiment, pregnant rats were randomly divided into four groups: the control group (corn oil, C), low dose group (2.5 mg/kg/day, L-NP group), medium dose group (50 mg/kg/day, M-NP group), and high dose group (100 mg/kg/day, H-NP group), with 12 rats in each group. The NP concentration in the hearts of offspring at PND21 and PND90 increased with the increase of the NP dose. Perinatal NP exposure induced a gradual increase in systolic blood pressure in offspring at PND90. In the H-NP group, there was a high degree of inflammatory cell infiltration, myofibril breaks, inconspicuous or absent nuclei, and pink collagen deposition. At PND90, the membrane integrity of mitochondria in the H-NP group was disrupted, the cristae disorder was aggravated, and there was internal lysis with vacuolation. Compared to the control group, the mitochondrial membrane potential of offspring at PND21 and PND90 was decreased in each of the NP exposure groups. NP exposure decreased the activity of mitochondrial respiratory enzyme complex I (CI) and increased the activity of mitochondrial respiratory enzyme complex IV (CIV) in the offspring. At PND21 and PND90, the mRNA and protein expression levels of cardiac mitochondrial PGC-1 alpha, NRF-1, and TFAM decreased with increasing NP dose in a dose-dependent manner. In the in vitro experiment, H9C2 cells were divided into the following four groups: the blank group, RSV group (15 mu g/ml), RSV + NP group (15 mu g/ml RSV + 120 mmol/ L NP), and NP group (120 mmol/L). With increasing NP concentration, the cell survival rate gradually decreased. Compared to the control, the membrane potential was significantly decreased in the NP group; the protein expression levels of SIRT1, PGC-1 alpha, NRF-1, and TFAM in the NP group were significantly lower. Conclusion: Perinatal NP exposure caused mitochondrial damage and dysfunction in the offspring of exposed individuals in a dose-dependent manner. This toxic effect may be related to NP-induced mitochondrial pathology in the offspring and the inhibition of both gene and protein expression involved in the PGC-1 alpha/NRF-1/TFAM mitochondrial biogenesis signaling pathway following NP exposure.

This study attempted to investigate whether exosomes derived from rat endothelial cells (EC-Exo) attenuate intimal hyperplasia after balloon injury using hematoxylin and eosin staining, immunohistochemistry, immunofluorescence staining, Evans blue staining, and Western blotting. The results indicated that EC-Exo inhibited intimal hyperplasia in the carotid artery after balloon injury, promoted re-endothelialization, and reduced vascular inflammation and ROS-NLRP3-mediated cell pyroptosis. Thus, EC-Exo can inhibit neointimal hyperplasia after carotid artery injury in rats presumably by inhibiting the ROS-NLRP3 inflammasome and phenotypic transformation of vascular smooth muscle cells.

Hypertension is an important risk factor for cardiovascular diseases (CVDs) and a leading cause of premature death. Epidemiological studies have found that perfluoroalkyl substances (PFASs) are associated with hypertension. However, the correlation between PFASs and hypertension has not been systematically reported. Based on evidence from population epidemiological surveys, we conducted a meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to assess the correlation between PFASs exposure and hypertension. In this study, three databases of PubMed, Web of science, Embase were searched and 13 literatures with 81,096 participants were included. Literature heterogeneity was evaluated by I2 statistic, and the random effect model (I2 > 50%) and fixed effect model (I2 < 50%) were used to combine the studies in meta-analysis. The results showed that PFNA (OR = 1.11, 95% CI: 1.04-1.19), PFOA (OR = 1.12, 95% CI: 1.02-1.23), PFOS (OR = 1.19, 95% CI: 1.06-1.34) and PFHxS (OR = 1.03, 95% CI: 1.00-1.06) were significantly associated with hypertension, while other types of PFASs (∑PFAS, PFDA, PFUnDA) had no statistical significance. In addition, PFNA (OR = 1.12, 95% CI: 1.03-1.22), PFOA (OR = 1.12, 95% CI: 1.01-1.25) and PFOS (OR = 1.12, 95% CI: 1.00-1.25) exposure were positively correlated with the risk of hypertension in men, but not in women. Our study reveals that PFASs are risk factors for hypertension, with notable gender differences observed in PFASs-exposed populations. Specifically, males exposed to PFNA, PFOA, and PFOS exhibit a higher risk of hypertension compared to females. However, further investigations are needed to delve into the precise mechanism through which PFASs contribute to the development of hypertension.

BACKGROUND:Exosomes released from cardiomyocytes (CMs) potentially play an important role in angiogenesis through microRNA (miR) delivery. Studies have reported an important role for miR-29a in regulating angiogenesis and pathological myocardial hypertrophy. However, whether CMderived exosomal miR-29a is involved in regulating cardiac microvascular endothelial cell (CMEC) homeostasis during myocardial hypertrophy has not been determined.METHODS:Angiotensin II (Ang II) was used to induce CM hypertrophy, and ultracentrifugation was then used to extract exosomes from a CM-conditioned medium. CMECs were cocultured with a conditioned medium in the presence or absence of exosomes derived from CMs (Nor-exos) or exosomes derived from angiotensin II-induced CMs (Ang II-exos). Moreover, a rescue experiment was performed using CMs or CMECs infected with miR-29a mimics or inhibitors. Tube formation assays, Transwell assays, and 5-ethynyl-20-deoxyuridine (EdU) assays were then performed to determine the changes in CMECs treated with exosomes. The miR-29a expression was measured by qRT-PCR, and Western blotting and flow cytometry assays were performed to evaluate the proliferation of CMECs.RESULTS:The results showed that Ang II-induced exosomal miR-29a inhibited the angiogenic ability, migratory function, and proliferation of CMECs. Subsequently, the downstream target gene of miR- 29a, namely, vascular endothelial growth factor (VEGFA), was detected by qRT-PCR and Western blotting, and the results verified that miR-29a targeted the inhibition of the VEGFA expression to subsequently inhibit the angiogenic ability of CMECs.CONCLUSION:Our results suggest that exosomes derived from Ang II-induced CMs are involved in regulating CMCE proliferation, migration, and angiogenesis by targeting VEGFA through the transfer of miR-29a to CMECs.

We aimed to explore the effects of myeloid-derived growth factor (Mydgf) on the regulation of hypoxia/reoxygenation (HR)–induced apoptosis of cardiac microvascular endothelial cells (CMECs). CMECs were exposed to hypoxia for 24 h and reoxygenation for 6 h to establish an HR cell model. Subsequently, an adenovirus was used to overexpress Mydgf in CMECs. Flow cytometry and TUNEL staining were used to detect the extent of apoptosis, whereas qPCR was used to detect the relative expression of Mydgf mRNA. Western blotting was also performed to detect the expression of apoptosis-related proteins and endoplasmic reticulum stress (ERS)–related proteins, including C/EBP Homologous Protein (CHOP), glucose-regulated protein 78 (GRP 78), and cleaved Caspase-12. The endoplasmic reticulum stress agonist tunicamycin (TM) was used to stimulate CMECs for 24 h as a rescue experiment for Mydgf. Flow cytometry revealed that the HR model effectively induced endothelial cell apoptosis, whereas qPCR and western blotting showed that Mydgf mRNA and protein levels decreased significantly after HR treatment (P < 0.05). Overexpression of Mydgf in cells effectively reduced apoptosis after HR. Furthermore, western blotting showed that HR induced a significant upregulation of CHOP, GRP78, and cleaved-Caspase-12 expression in CMECs, whereas HR-treated cells downregulated the expression of CHOP, GRP78, and cleaved-Caspase-12 after Mydgf overexpression. Under HR conditions, TM significantly reversed the protective effect of Mydgf on CMECs. Mydgf may reduce CMEC apoptosis induced by HR by regulating oxidative stress in ERS.

Myocardial infarction is one of the leading diseases causing death and disability worldwide, and the revascularization of damaged tissues is essential for myocardial-injury repair. Circular RNAs (circRNAs) are widely involved in physiological and pathological processes in various systems throughout the body, and the role of circRNAs in cardiovascular disease is gaining attention. In this study, we determined that circERBB2IP is highly expressed in the hearts of newborn mice. Silencing or overexpression of circERBB2IP inhibited and promoted angiogenesis in vivo and in vitro, respectively. Mechanistically, the transcription factor GATA4 promotes the production of circERBB2IP. Furthermore, circERBB2IP functioned as an endogenous miR-145a-5p sponge and was able to sequester and repress miR-145a-5p activity, which led to an increased expression level of Smad5. In summary, circERBB2IP can promote angiogenesis after myocardial infarction through the miR-145a-5p/Smad5 axis. These data for the treatment of myocardial infarction.

This study aimed to explore whether zinc-selenium tea has an curative effect on the cardiotoxicity induced by nonylphenol (NP), and to compare the effect of zinc-selenium tea and green tea. After drinking of zinc-selenium tea or green tea, compared with the control group, the left ventricular anterior wall became thinner, and the left ventricular end-diastolic diameter increased, the anterior wall of the left ventricle became thin at the end of diastole in the NP group. The serum myocardial enzymes aspartate aminotransferase, creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase in the NP group were significantly increased, and the serum myocardial enzymes were significantly decreased after the intervention of zinc-selenium tea. Proteins and mRNA expressions of Collagen I and Collagen III in the tea groups were lower than those in the NP group. In the green tea and zinc-selenium tea intervention groups, the disorder and degree of myocardial fiber were alleviated to varying degrees. The disturbance, breakage, and inflammatory cell infiltration of myocardial fibers in zinc-selenium tea and green tea groups were less than that of NP group. After tea intervention, collagen I and collagen III in the myocardium decreased. The intervention effect of zinc-selenium tea was better than that of green tea. Zinc-selenium tea and green tea could interfere with the cardiotoxicity indued by NP, which would alleviate the myocardial fibrosis by reducing expressions of collagen I and collagen III. Moreover, the curative effect of zinc-selenium tea was better than that of green tea.

N6-methylatidine (m6A) is involved in post-transcriptional metabolism and a variety of pathological processes. However, little is known about the role of m6A in vascular proliferative diseases, particularly in vascular smooth muscle cells (VSMCs) phenotype switching-induced neointimal hyperplasia. In the current study, we discovered that methyltransferase like 3 (METTL3) is a critical candidate for catalyzing a global increase in m6A in response to carotid artery injury and various VSMCs phenotype switching. The inhibited neointimal hyperplasia was obtained after in vivo gene transfer to knock-down Mettl3. In vitro overexpression of Mettl3 resulted in increased VSMC proliferation, migration, and reduced contractile gene expression with a global elevation of m6A modification. In contrast, Mettl3 knockdown reversed this facilitated phenotypic switch in VSMCs, as demonstrated by downregulated m6A, decreased proliferation, migration, and increased expression of contractile genes. Mechanistically, Mettl3 knock-down was found to promote higher phosphatidylinositol 3-kinase (Pi3k) mRNA decay thus inactivating the PI3K/AKT signal to inhibit VSMCs phenotype switching. Overall, our findings highlight the importance of METTL3-mediated m6A in VSMCs phenotype switching and offer a novel perspective on targeting METTL3 as a therapeutic option for VSMCs phenotype switching modulated pathogenesis, including atherosclerosis and restenosis.

Objective To investigate whether myeloid-derived growth factor (Mydgf) can improve cardiomyocyte pyroptosis induced by hyperglycemia by regulating nucleotide-binding domain-like receptor protein 3 (NLRP3). Methods Cultured rat cardiomyocyte H9c2 cells were divided into 4 groups: normal group (Nor), high glucose group (HG, 50 mmol/L glucose for 24 h), Mydgf group (25 ng/mL recombinant Mydgf protein for 12 h, followed by 50 mmol/L glucose for 24 h), and necrosulfonamide group (NSA, 32 μmol/L necrosulfonamide for 0.5 h, followed by 50 mmol/L glucose for 24 h). Western blotting was used to detect the protein levels of cleaved Caspase-1, NLRP3, apoptosis-related speckle-like proteins (ACS) and gasdermin D (GSDMD). The secretions of IL-1β and IL-18 in cell culture medium were detected by ELISA. CCK-8 assay was used to detect the effect of Mydgf or NLRP3 on the viability of H9c2 cells. Lentiviral vector carrying NLRP3 and enhanced green fluorescent protein (EGFP) (NLRP3-EGFP) and empty viral vector (EGFP) were transfected into H9c2 cells respectively, and the changes of pyroptosis related indexes were detected by recovery experiments. Results Western blot results showed that the expression levels of pyroptosis related proteins, cleaved Caspase 1, ACS, NLRP3 and GSDMD were significantly higher in the HG group than the Nor group (P < 0.05). Mydgf treatment effectively inhibited the expression of above proteins (P < 0.05), but the inhibitory efficiencies were lower than that in the NSA group (P < 0.05). ELISA demonstrated that the secretions of IL-1β and IL-18 were increased in the HG group (P < 0.05), but decreased in the Mydgf group (P < 0.05), and more significantly reduced in the NSA group (P < 0.05). CCK-8 assay indicated that Mydgf at a concentration of below 25 ng/mL had no significant effect on the viability of H9c2 cells, while when the concentration above 25 ng/mL, the treatment significantly decreased the cell viability (P < 0.05). Compared with the control group, overexpression of NLRP3 significantly decreased H9c2 cells viability under the condition of HG. Transfection of lentiviral vector NLRP3-EGFP resulted in obvious increases in the mRNA and protein expression of NLRP3 (P < 0.05), but that of empty vector had no such effects (P>0.05). In the recovery experiment, Western blot results showed that in the high-glucose environment, the expression level of NLRP3, ASC, and cleaved Caspase-1 were significantly increased (P < 0.05), and the secretions of IL-1β and IL-18 were also significantly enhanced in the Mydgf +NLRP3-EGFP group compared with the Mydgf group (P < 0.05). Conclusion Mydgf may ameliorate cardiomyocyte pyroptosis induced by hyperglycemia by inhibiting NLRP3.

目的 骨髓间充质干细胞(BMSCs)能够在多种心血管疾病病理过程中发挥重要作用,但其对支架内再狭窄的影响有待进一步研究.文中旨在探讨BMSCs源外泌体对大鼠颈动脉球囊损伤后新生内膜增殖的影响及circRNA和microRNA表达变化.方法 采用差速超速离心法提取大鼠BMSCs源外泌体,并使用Western blot及透射电镜对其进行鉴定.采用球囊损伤大鼠颈动脉的方法建立血管内膜增生动物模型,将36只成年雄性SD大鼠随机分为:假手术组、损伤组、外泌体组(400μL);假手术组大鼠只分离颈左总动脉血管,其余各组大鼠的左颈总动脉均行球囊损伤,外泌体组行球囊损伤后立即原位注射400μL BMSCs源外泌体并用微型血管夹夹闭血管5 min.采用HE染色检测内膜增生情况,DCFH-DA染色检测血管活性氧(ROS)释放情况.采用circRNA和microRNA芯片筛查差异表达的circRNA和microRNA,并以每组3个样本对其中显著差异的8个circRNA和7个microRNA进行qRT-PCR验证,并筛选出BMSCs源外泌体处理后差异表达的circRNA和microRNA;生物信息学方法预测差异microRNA的靶基因,并进行GO分析和KEGG通路分析,构建circRNA-microRNA-mRNA共表达网络,对其潜在分子机制进行探讨.结果 透射电镜及Western blot验证提取的囊泡状物质为外泌体;HE染色结果显示:损伤组较假手术组新生内膜增殖明显,其内膜/中膜面积比(1.902±0.217)较假手术组(1.000±0.000)显著增加(P<0.05);外泌体组较损伤组新生内膜增殖程度有所减低,其内膜/中膜面积比(0.982±0.067)较损伤组明显减低(P<0.05).DCFH-DA染色结果显示:与假手术组DCFHA红色荧光强度(4.730±0.104)相比,损伤组(16.800±0.380)明显增强(P<0.05);与损伤组相比,外泌体组DCFHA红色荧光强度(12.810±0.094)明显减弱(P<0.05).circRNA芯片显示差异性表达的circRNA共1683个(Fold change≥2,P<0.05).与假手术组相比,损伤组中上调的有631个,下调的有1052个.microRNA芯片显示有差异microRNA共44个(Fold change≥2,P<0.05),且均在损伤组上调.GO分析和KEGG分析表明,microRNA的预测靶基因参与了细胞生物学进程正向调控、细胞间紧密连接、激酶活性等方面有关,并在MAPK信号通路、Ras信号通路、Hippo信号通路等等中富集.结合芯片和qRT-PCR结果,筛选出BMSCs源外泌体处理后损伤颈动脉组织中差异表达明显的有circRNA_004976、circRNA_008565、circRNA_017449以及miR-20a-5p、miR-146a-5p、miR-21-5p(P<0.05).结论 BMSCs源外泌体可以抑制大鼠颈动脉球囊损伤后内膜增生,其潜在机制可能与circRNA_004976、circRNA_008565以及miR-20a-5p、miR-21-5p等分子调控细胞增殖、迁移有关.

Autophagy and apoptosis are involved in myocardial ischemia/reperfusion (I/R) injury. Research indicates that circular RNA HIPK3 (circHIPK3) is crucial to cell autophagy and apoptosis in various cancer types. However, the role of circHIPK3 in the regulation of cardiomyocyte autophagy and apoptosis during I/R remains unknown. Our study aimed to examine the regulatory effect of circHIPK3 during myocardial I/R and investigate its mechanism in cardiomyocyte autophagy and apoptosis. Methods and results. The expression of circHIPK3 was upregulated during myocardial I/R injury and hypoxia/reoxygenation (H/R) injury of cardiomyocytes. To study the potential role of circHIPK3 in myocardial H/R injury, we performed gain-of-function and loss-of-function analyses of circHIPK3 in cardiomyocytes. Overexpression of circHIPK3 significantly promoted H/R-induced cardiomyocyte autophagy and cell injury (increased intracellular reactive oxygen species (ROS) and apoptosis) compared to those in the control group, while silencing of circHIPK3 showed the opposite effect. Further research found that circHIPK3 acted as an endogenous miR-20b-5p sponge to sequester and inhibit miR-20b-5p activity, resulting in increased ATG7 expression. In addition, miR-20b-5p inhibitors reversed the decrease in ATG7 induced by silencing circHIPK3. Conclusions. CircHIPK3 can accelerate cardiomyocyte autophagy and apoptosis during myocardial I/R injury through the miR-20b-5p/ATG7 axis. These data suggest that circHIPK3 may serve as a potential therapeutic target for I/R.

目的 探讨miR-221在急性心肌梗死(AMI)大鼠心肌损伤中的作用及相关机制.方法 通过冠状动脉左前降支结扎大鼠建立AMI模型,将构建成功的36只AMI大鼠模型随机分为AMI组、对照组及抑制组,另外设立假手术组采用冠状动脉左前降支穿线不结扎,每组各12只.抑制组和对照组分别采用心肌组织局部注射慢病毒转染的miR-221抑制剂及miR-221 NC,AMI组和假手术组每天给予等量生理盐水,隔日1次,连续2 w.实时定量-聚合酶链反应(PCR)检测miR-221表达,记录大鼠心脏功能,并采用原位末端凋亡法(Tunel)检测心肌凋亡指数(AI),紫外分光光度法检测含半胱氨酸的天冬氨酸蛋白水解酶(Caspase)3及Caspase-9活性,Western印迹检测Bcl-2、Bax,增殖细胞核抗原(PCNA),Ki67蛋白表达及细胞外蛋白调节激酶(ERK1/2)磷酸化水平.结果 与假手术组miR-211表达量相比,AMI组显著提高(P<0.01).与假手术组miR-211表达量相比,AMI组及对照组均显著提高(P<0.01);与AMI组及对照组相比,抑制组显著降低(P<0.01).与假手术组和抑制组比较AMI组及对照组左室射血分数(LVEF)、左室长轴缩短分数(FS)水平均显著降低,而左室舒张末期内径(LVEDD)及左室收缩末期内径(LVESD)水平均显著升高(P<0.01).与假手术组心肌AI相比,AMI组及对照组均显著提高(P<0.01);与AMI组及对照组相比,抑制组显著降低(P<0.01).与假手术组相比,AMI组及对照组中心肌组织中Caspase-3及Caspase-9活性明显升高(P<0.01);与AMI组及对照组相比,抑制组中心肌组织中Caspase-3及Caspase-9活性显著降低(P<0.01).与假手术组比较,AMI组及对照组中Bcl-2、PCNA及Ki67表达量明显下调(P<0.01),Bax表达量明显上调(P<0.01);与AMI组及对照组比较,抑制组中Bcl-2、PCNA及Ki67表达量明显上调(P<0.01),Bax表达量明显下调(P<0.01).与假手术组p-ERK1/2表达量比较,AMI组及对照组明显下调(P<0.01);与AMI组及对照组比较,抑制组明显上调(P<0.01).结论 miR-221低表达能显著AMI大鼠心肌损伤,与上调EKR1/2磷酸化水平相关.