Nicorandil-Pretreated Mesenchymal Stem Cell-Derived Exosomes Facilitate Cardiac Repair After Myocardial Infarction via Promoting Macrophage M2 Polarization by Targeting miR-125a-5p/TRAF6/IRF5 Signaling Pathway.

Background: Exosomes derived from bone marrow mesenchymal stem cells (MSC-exo) have been considered as a promising cell-free therapeutic strategy for ischemic heart disease. Cardioprotective drug pretreatment could be an effective approach to improve the efficacy of MSC-exo. Nicorandil has long been used in clinical practice for cardioprotection. This study aimed to investigate whether the effects of exosomes derived from nicorandil pretreated MSC (MSCNIC-exo) could be enhanced in facilitating cardiac repair after acute myocardial infarction (AMI). Methods: MSCNIC-exo and MSC-exo were collected and injected into the border zone of infarcted hearts 30 minutes after coronary ligation in rats. Macrophage polarization was detected 3 days post-infarction, cardiac function as well as histological pathology were measured on the 28th day after AMI. Macrophages were separated from the bone marrow of rats for in vitro model. Exosomal miRNA sequencing was conducted to identify differentially expressed miRNAs between MSCNIC-exo and MSC-exo. MiRNA mimics and inhibitors were transfected to MSCs or macrophages to explore the specific mechanism. Results: Compared to MSC-exo, MSCNIC-exo showed superior therapeutic effects on cardiac functional and structural recovery after AMI and markedly elevated the ratio of CD68+ CD206+/ CD68+cells in infarcted hearts 3 days post-infarction. The notable ability of MSCNIC-exo to promote macrophage M2 polarization was also confirmed in vitro. Exosomal miRNA sequencing and both in vivo and in vitro experiments identified and verified that miR-125a-5p was an effector of the roles of MSCNIC-exo in vivo and in vitro. Furthermore, we found miR-125a-5p promoted macrophage M2 polarization by inhibiting TRAF6/IRF5 signaling pathway. Conclusion: This study suggested that MSCNIC-exo could markedly facilitate cardiac repair post-infarction by promoting macrophage M2 polarization by upregulating miR-125a-5p targeting TRAF6/IRF5 signaling pathway, which has great potential for clinical translation.

Correlation between ESR1 and APOE gene polymorphisms and risk of osteonecrosis of the femoral head: a case-control study.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a disease with a high disability rate, and genetic factors are closely related to its pathogenesis. This study aimed to investigate the possible correlation between ESR1 and APOE gene polymorphisms and the risk of ONFH. METHODS: In this case-control study, the potential association between three genetic variants (rs2982573 C < T, rs10872678 C < T, and rs9322332 A < C) of the ESR1 gene and two genetic variants (rs7259620 A < G and rs769446 C < T) of the APOE gene with the risk of ONFH was investigated. Correlations between gene polymorphisms and ONFH risk were assessed using logistic regression analysis, with calculation of odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The overall analysis demonstrated that rs9322332 in the ESR1 gene exhibited a correlation with a decreased risk of ONFH under the homozygous (AA vs.CC: OR = 0.69, 95% CI [0.53-0.90], p = 0.006), dominant (CA + AA vs. CC: OR = 0.70, 95% CI [0.54-0.90], p = 0.006), and additive (OR = 0.79, 95% CI [0.66-0.95], p = 0.013) models. The stratification analysis revealed that rs9322332 was linked to a lower risk of ONFH in subgroups characterized by individuals aged over 51 years and non-smokers. Nevertheless, there were no notable correlations found between ESR1 rs2982573 and rs10872678, as well as APOE rs7259620 and rs769446, with the risk of ONFH. CONCLUSION: ESR1-rs9322332 is closely linked to a decreased risk of ONFH, thereby enhancing our understanding of the relationship between gene polymorphisms and ONFH.

Identification of A Novel Gene Signature Combining Ferroptosis- and Immunity-Related Genes for Prognostic Prediction, Immunotherapy and Potential Therapeutic Targets in Gastric Cancer.

Gastric cancer (GC) is one of the most prevalent cancers worldwide. Ferroptosis and the immune status of tumor tissue play vital roles in the initiation and progression of GC. However, the role and functional mechanisms of ferroptosis- and immunity-related genes (FIRGs) in GC pathogenesis and their correlations with GC prognosis have not been elucidated. We aim to establish a prognostic prediction model based on the FIRGs signature for GC patients. Differentially expressed genes were screened from the Cancer Genome Atlas (TCGA) GC cohorts. The least absolute shrinkage and selection operator (LASSO) regression was performed to establish a FIRGs-based risk model. This gene signature with 7 FIRGs was identified as an independent prognostic factor. A nomogram incorporating clinical parameters and the FIRG signature was constructed to individualize outcome predictions. Finally, we provided in vivo and in vitro evidence to verify the reliability of FIRG signature for GC prognosis, and validate the expression and function of FIRGs contributing to the development and progression of GC. Herein, our work represents great therapeutic and prognostic potentials for GC.

Mitochondrial-derived peptides in cardiovascular disease: Novel insights and therapeutic opportunities.

BACKGROUND: Mitochondria-derived peptides (MDPs) represent a recently discovered family of peptides encoded by short open reading frames (ORFs) found within mitochondrial genes. This group includes notable members including humanin (HN), mitochondrial ORF of the 12S rDNA type-c (MOTS-c), and small humanin-like peptides 1-6 (SHLP1-6). MDPs assume pivotal roles in the regulation of diverse cellular processes, encompassing apoptosis, inflammation, and oxidative stress, which are all essential for sustaining cellular viability and normal physiological functions. Their emerging significance extends beyond this, prompting a deeper exploration into their multifaceted roles and potential applications. AIM OF REVIEW: This review aims to comprehensively explore the biogenesis, various types, and diverse functions of MDPs. It seeks to elucidate the central roles and underlying mechanisms by which MDPs participate in the onset and development of cardiovascular diseases (CVDs), bridging the connections between cell apoptosis, inflammation, and oxidative stress. Furthermore, the review highlights recent advancements in clinical research related to the utilization of MDPs in CVD diagnosis and treatment. KEY SCIENTIFIC CONCEPTS OF REVIEW: MDPs levels are diminished with aging and in the presence of CVDs, rendering them potential new indicators for the diagnosis of CVDs. Also, MDPs may represent a novel and promising strategy for CVD therapy. In this review, we delve into the biogenesis, various types, and diverse functions of MDPs. We aim to shed light on the pivotal roles and the underlying mechanisms through which MDPs contribute to the onset and advancement of CVDs connecting cell apoptosis, inflammation, and oxidative stress. We also provide insights into the current advancements in clinical research related to the utilization of MDPs in the treatment of CVDs. This review may provide valuable information with MDPs for CVD diagnosis and treatment.

ß-cell neogenesis: A rising star to rescue diabetes mellitus.

BACKGROUND: Diabetes Mellitus (DM), a chronic metabolic disease characterized by elevated blood glucose, is caused by various degrees of insulin resistance and dysfunctional insulin secretion, resulting in hyperglycemia. The loss and failure of functional ß-cells are key mechanisms resulting in type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). AIM OF REVIEW: Elucidating the underlying mechanisms of ß-cell failure, and exploring approaches for ß-cell neogenesis to reverse ß-cell dysfunction may provide novel strategies for DM therapy. KEY SCIENTIFIC CONCEPTS OF REVIEW: Emerging studies reveal that genetic susceptibility, endoplasmic reticulum (ER) stress, oxidative stress, islet inflammation, and protein modification linked to multiple signaling pathways contribute to DM pathogenesis. Over the past few years, replenishing functional ß-cell by ß-cell neogenesis to restore the number and function of pancreatic ß-cells has remarkably exhibited a promising therapeutic approach for DM therapy. In this review, we provide a comprehensive overview of the underlying mechanisms of ß-cell failure in DM, highlight the effective approaches for ß-cell neogenesis, as well as discuss the current clinical and preclinical agents research advances of ß-cell neogenesis. Insights into the challenges of translating ß-cell neogenesis into clinical application for DM treatment are also offered.

Decrypting the circular RNAs does a favor for us: Understanding, diagnosing and treating diabetes mellitus and its complications.

Circular RNAs (circRNAs), a novel type of single-stranded noncoding RNAs with a covalently closed loop structure, are generated in a circular conformation via non-canonical splicing or back-splicing events. Functionally, circRNAs have been elucidated to soak up microRNAs (miRNAs) and RNA binding proteins (RBPs), serve as protein scaffolds, maintain mRNA stability, and regulate gene transcription and translation. Notably, circRNAs are strongly implicated in the regulation of ß-cell functions, insulin resistance, adipocyte functions, inflammation as well as oxidative stress via acting as miRNA sponges and RBP sponges. Basic and clinical studies have demonstrated that aberrant alterations of circRNAs expressions are strongly associated with the initiation and progression of diabetes mellitus (DM) and its complications. Here in this review, we present a summary of the biogenesis, transportation, degradation and functions of circRNAs, and highlight the recent findings on circRNAs and their action mechanisms in DM and its complications. Overall, this review should contribute greatly to our understanding of circRNAs in DM pathogenesis, offering insights into the further perspectives of circRNAs for DM diagnosis and therapy.

m6 A mRNA methylation: Biological features, mechanisms, and therapeutic potentials in type 2 diabetes mellitus.

As the most common internal post-transcriptional RNA modification in eukaryotic cells, N6-methyladenosine (m6 A) performs a dynamic and reversible role in a variety of biological processes mediated by methyltransferases (writers), demethylases (erasers), and m6 A binding proteins (readers). M6 A methylation enables transcriptome conversion in different signals that regulate various physiological activities and organ development. Over the past few years, emerging studies have identified that mRNA m6 A regulators defect in ß-cell leads to abnormal regulation of the target mRNAs, thereby resulting in ß-cell dysfunction and loss of ß-cell identity and mass, which are strongly associated with type 2 diabetes mellitus (T2DM) pathogenesis. Also, mRNA m6 A modification has been implicated with insulin resistance in muscles, fat, and liver cells/tissues. In this review, we elaborate on the biological features of m6 A methylation; provide a comprehensive overview of the underlying mechanisms that how it controls ß-cell function, identity, and mass as well as insulin resistance; highlight its connections to glucose metabolism and lipid metabolism linking to T2DM; and further discuss its role in diabetes complications and its therapeutic potentials for T2DM diagnosis and treatment.

HEATR3 involved in the cell proliferation, metastasis and cell cycle development of bladder cancer acts as a tumor suppressor.

The study was designed to detect the expression and clinical significance of the HEATR3 gene in bladder cancer (BCa) and to preliminarily explore whether this gene can affect the occurrence and development of BCa through the AKT/ERK signaling pathway. The expression and prognostic value of HEATR3 were explored based on The Cancer Genome Atlas (TCGA) and Genotypic Tissue Expression (GTEx) databases. Microarray immunohistochemical analysis was performed in 30 BCa cases to investigate the level of HEATR3 protein and to explore the relationship between HEATR3 and the clinicopathological features of BCa. Western Blot and qRT-PCR were used to detect HEATR3 protein and mRNA in BCa cell lines (5637, TCCSUP, SW780) and fallopian tube epithelial cell (SV-HUC-1). CCK8 method was employed to study the proliferation of BCa cells after heat treatment. Transwell assay was conducted to analyze the effect of HEATR3 on cell migration and invasion. And cell cycle and apoptosis were detected by flow cytometry. Furthermore, Western Blot assay was used to probe the effects of down-regulation of HEATR3 expression on the expression and phosphorylation levels of AKT and ERK proteins in BCa cells. Bioinformatics analysis showed that HEATR3 was significantly up-regulated in BCa, and high HEATR3 expression was associated with poor prognosis of BCa patients. In vitro experiments demonstrated that HEATR3 expression was up-regulated in BCa tissues compared with that in adjacent tissues. HEATR3 protein was also up-regulated in malignant cell lines. HEATR3 knockdown in BCa cells could inhibit cell proliferation, invasion and migration, block cell cycle and promote cell apoptosis. At the same time, HEATR3 knockdowns reduced the expression levels of p-AKT and p-ERK proteins. HEATR3 knockdown inhibits the development of BCa cells through the AKT/ERK signaling pathway. and it may become one of the most promising molecular targets for BCa treatment.

Aberrant hyper-expression of the RNA binding protein GIGYF2 in endothelial cells modulates vascular aging and function.

Vascular endothelial cells (ECs) senescence plays a crucial role in vascular aging that promotes the initiation and progression of cardiovascular disease. The mutation of Grb10-interacting GYF protein 2 (GIGYF2) is strongly associated with the pathogenesis of aging-related diseases, whereas its role in regulating ECs senescence and dysfunction still remains elusive. In this study, we found aberrant hyperexpression of GIGYF2 in senescent human ECs and aortas of old mice. Silencing GIGYF2 in senescent ECs suppressed eNOS-uncoupling, senescence, and endothelial dysfunction. Conversely, in nonsenescent cells, overexpressing GIGYF2 promoted eNOS-uncoupling, cellular senescence, endothelial dysfunction, and activation of the mTORC1-SK61 pathway, which were ablated by rapamycin or antioxidant N-Acetyl-l-cysteine (NAC). Transcriptome analysis revealed that staufen double-stranded RNA binding protein 1 (STAU1) is remarkably downregulated in the GIGYF2-depleted ECs. STAU1 depletion significantly attenuated GIGYF2-induced cellular senescence, dysfunction, and inflammation in young ECs. Furthermore, we disclosed that GIGYF2 acting as an RNA binding protein (RBP) enhances STAU1 mRNA stability, and that the intron region of the late endosomal/lysosomal adaptor MAPK and mTOR activator 4 (LAMTOR4) could bind to STAU1 protein to upregulate LAMTOR4 expression. Immunofluorescence staining showed that GIGYF2 overexpression promoted the translocation of mTORC1 to lysosome. In the mice model, GIGYF2flox/flox Cdh-Cre+ mice protected aged mice from aging-associated vascular endothelium-dependent relaxation and arterial stiffness. Our work discloses that GIGYF2 serving as an RBP enhances the mRNA stability of STAU1 that upregulates LAMTOR4 expression through binding with its intron region, which activates the mTORC1-S6K1 signaling via recruitment of mTORC1 to the lysosomal membrane, ultimately leading to ECs senescence, dysfunction, and vascular aging. Disrupting the GIGYF2-STAU1-mTORC1 signaling cascade may represent a promising therapeutic approach against vascular aging and aging-related cardiovascular diseases.

The lncRNA OIP5-AS1/miR-4500 axis targeting ARG2 modulates oxidative stress-induced premature senescence in endothelial cells: implications for vascular aging.

BACKGROUND: Endothelial senescence due to increased age or oxidative stress can cause endothelial dysfunction, which is strongly associated with the pathogenesis of cardiovascular diseases (CVDs). RESEARCH DESIGN AND METHODS: Hydrogen peroxide (H2O2) was used to induced human umbilical vein endothelial cells (HUVECs) senescence model. Cell senescence and cell proliferation were assessed by SA-ß-gal staining and PCNA staining. Nitric oxide (NO) and reactive oxygen species (ROS) levels were detected by DAF-2 DA and DCFH-DA. Inflammatory indicators were quantified by qPCR. Meanwhile, western blot was used to examine the ARG2 protein. Finally, an aging mice model induced by H2O2 was established to confirm the role of OIP5-AS1/miR-4500/ARG2 in endothelial dysfunction in vivo. RESULTS: ARG2 was upregulated and miR-4500 was reduced in H2O2-induced HUVECs. MiR-4500 negatively regulates ARG2 expression, meanwhile ameliorating H2O2-induced ECs senescence and dysfunction. Targeted interactions among OIP5-AS1, miR-4500, and ARG2 were confirmed by dual-luciferase reporter assays. OIP5-AS1 as miR4500 sponge negatively mediates miR-4500 expression, and is upregulated upon H2O2 stimulation in HUVECs. OIP5-AS1 depletion shows the protective effects on H2O2-induced ECs senescence, dysfunction, and SASP. In vivo, a higher expression of OIP5-AS1 and ARG2 in the aortas of aged mice. CONCLUSIONS: We disclosed a regulatory mechanism for OIP5-AS1/miR-4500/ARG2 in the regulation of oxidative stress-related ECs senescence and vascular aging.

Levosimendan Reverses Cardiac Malfunction and Cardiomyocyte Ferroptosis During Heart Failure with Preserved Ejection Fraction via Connexin 43 Signaling Activation.

PURPOSE: In recent decades, the occurrence of heart failure with preserved ejection fraction (HFpEF) has outweighed that of heart failure with reduced ejection fraction by degrees, but few drugs have been demonstrated to improve long-term clinical outcomes in patients with HFpEF. Levosimendan, a calcium-sensitizing cardiotonic agent, improves decompensated heart failure clinically. However, the anti-HFpEF activities of levosimendan and underlying molecular mechanisms are unclear. METHODS: In this study, a double-hit HFpEF C57BL/6N mouse model was established, and levosimendan (3 mg/kg/week) was administered to HFpEF mice aged 13 to 17 weeks. Different biological experimental techniques were used to verify the protective effects of levosimendan against HFpEF. RESULTS: After four weeks of drug treatment, left ventricular diastolic dysfunction, cardiac hypertrophy, pulmonary congestion, and exercise exhaustion were significantly alleviated. Junction proteins in the endothelial barrier and between cardiomyocytes were also improved by levosimendan. Among the gap junction channel proteins, connexin 43, which was especially highly expressed in cardiomyocytes, mediated mitochondrial protection. Furthermore, levosimendan reversed mitochondrial malfunction in HFpEF mice, as evidenced by increased mitofilin and decreased ROS, superoxide anion, NOX4, and cytochrome C levels. Interestingly, after levosimendan administration, myocardial tissue from HFpEF mice showed restricted ferroptosis, indicated by an increased GSH/GSSG ratio; upregulated GPX4, xCT, and FSP-1 expression; and reduced intracellular ferrous ion, MDA, and 4-HNE levels. CONCLUSION: Regular long-term levosimendan administration can benefit cardiac function in a mouse model of HFpEF with metabolic syndromes (namely, obesity and hypertension) by activating connexin 43-mediated mitochondrial protection and sequential ferroptosis inhibition in cardiomyocytes.

ETNPPL modulates hyperinsulinemia-induced insulin resistance through the SIK1/ROS-mediated inactivation of the PI3K/AKT signaling pathway in hepatocytes.

Hyperinsulinemia is a critical risk factor for the pathogenesis of insulin resistance (IR) in metabolic tissues, including the liver. Ethanolamine phosphate phospholyase (ETNPPL), a newly discovered metabolic enzyme that converts phosphoethanolamine (PEA) to ammonia, inorganic phosphate, and acetaldehyde, is abundantly expressed in liver tissue. Whether it plays a role in the regulation of hyperinsulinemia-induced IR in hepatocytes remains elusive. Here, we established an in vitro hyperinsulinemia-induced IR model in the HepG2 human liver cancer cell line and primary mouse hepatocyte via a high dose of insulin treatment. Next, we overexpressed ETNPPL by using lentivirus-mediated ectopic to investigate the effects of ETNPPL per se on IR without insulin stimulation. To explore the underlying mechanism of ETNPPL mediating hyperinsulinemia-induced IR in HepG2, we performed genome-wide transcriptional analysis using RNA sequencing (RNA-seq) to identify the downstream target gene of ETNPPL. The results showed that ETNPPL expression levels in both mRNA and protein were significantly upregulated in hyperinsulinemia-induced IR in HepG2 and primary mouse hepatocytes. Upon silencing ETNPPL, hyperinsulinemia-induced IR was ameliorated. Under normal conditions without IR in hepatocytes, overexpressing ETNPPL promotes IR, reactive oxygen species (ROS) generation, and AKT inactivation. Transcriptome analysis revealed that salt-inducible kinase 1 (SIK1) is markedly downregulated in the ETNPPL knockdown HepG2 cells. Moreover, disrupting SIK1 prevents ETNPPL-induced ROS accumulation, damage to the PI3K/AKT pathway and IR. Our study reveals that ETNPPL mediates hyperinsulinemia-induced IR through the SIK1/ROS-mediated inactivation of the PI3K/AKT signaling pathway in hepatocyte cells. Targeting ETNPPL may present a potential strategy for hyperinsulinemia-associated metabolic disorders such as type 2 diabetes.

Atorvastatin-pretreated mesenchymal stem cell-derived extracellular vesicles promote cardiac repair after myocardial infarction via shifting macrophage polarization by targeting microRNA-139-3p/Stat1 pathway.

BACKGROUND: Extracellular vesicles (EVs) derived from bone marrow mesenchymal stem cells (MSCs) pretreated with atorvastatin (ATV) (MSCATV-EV) have a superior cardiac repair effect on acute myocardial infarction (AMI). The mechanisms, however, have not been fully elucidated. This study aims to explore whether inflammation alleviation of infarct region via macrophage polarization plays a key role in the efficacy of MSCATV-EV. METHODS: MSCATV-EV or MSC-EV were intramyocardially injected 30 min after coronary ligation in AMI rats. Macrophage infiltration and polarization (day 3), cardiac function (days 0, 3, 7, 28), and infarct size (day 28) were measured. EV small RNA sequencing and bioinformatics analysis were conducted for differentially expressed miRNAs between MSCATV-EV and MSC-EV. Macrophages were isolated from rat bone marrow for molecular mechanism analysis. miRNA mimics or inhibitors were transfected into EVs or macrophages to analyze its effects on macrophage polarization and cardiac repair in vitro and in vivo. RESULTS: MSCATV-EV significantly reduced the amount of CD68+ total macrophages and increased CD206+ M2 macrophages of infarct zone on day 3 after AMI compared with MSC-EV group (P < 0.01-0.0001). On day 28, MSCATV-EV much more significantly improved the cardiac function than MSC-EV with the infarct size markedly reduced (P < 0.05-0.0001). In vitro, MSCATV-EV also significantly reduced the protein and mRNA expressions of M1 markers but increased those of M2 markers in lipopolysaccharide-treated macrophages (P < 0.05-0.0001). EV miR-139-3p was identified as a potential cardiac repair factor mediating macrophage polarization. Knockdown of miR-139-3p in MSCATV-EV significantly attenuated while overexpression of it in MSC-EV enhanced the effect on promoting M2 polarization by suppressing downstream signal transducer and activator of transcription 1 (Stat1). Furthermore, MSCATV-EV loaded with miR-139-3p inhibitors decreased while MSC-EV loaded with miR-139-3p mimics increased the expressions of M2 markers and cardioprotective efficacy. CONCLUSIONS: We uncovered a novel mechanism that MSCATV-EV remarkably facilitate cardiac repair in AMI by promoting macrophage polarization via miR-139-3p/Stat1 pathway, which has the great potential for clinical translation.

ETNPPL impairs autophagy through regulation of the ARG2-ROS signaling axis, contributing to palmitic acid-induced hepatic insulin resistance.

Excessive free fatty acids (FFAs) accumulation is a leading risk factor for the pathogenesis of insulin resistance (IR) in metabolic tissues, including the liver. Ethanolamine-phosphate phospho-lyase (ETNPPL), a newly identified metabolic enzyme, catalyzes phosphoethanolamine (PEA) to ammonia, inorganic phosphate, and acetaldehyde and is highly expressed in hepatic tissue. Whether it plays a role in regulating FFA-induced IR in hepatocytes has yet to be understood. In this study, we established an in vitro palmitic acid (PA)-induced IR model in human HepG2 cells and mouse AML12 cells with chronic treatment of PA. Next, we overexpressed ETNPPL by using lentivirus-mediated ectopic to investigate the effects of ETNPPL per se on IR without PA stimulation. We show that ETNPPL expression is significantly elevated in PA-induced IR and that silencing ETNPPL ameliorates this IR in hepatocytes. Inversely, overexpressing ETNPPL under normal conditions without PA promotes IR, reactive oxygen species generation, and ARG2 activation in both HepG2 and AML12 cells. Moreover, ETNPPL depletion markedly down-regulates ARG2 expression in hepatocytes. Besides, silencing ARG2 prevents ETNPPL-induced ROS accumulation and inhibition of autophagic flux and IR in hepatocytes. Finally, we found that phytopharmaceutical disruption of ETNPPL by quercetin ameliorates PA-induced IR in hepatocytes. Our study discloses that ETNPPL inhibiting autophagic flux mediates insulin resistance triggered by PA in hepatocytes via ARG2/ROS signaling cascade. Our findings provide novel insights into elucidating the pathogenesis of obesity-associated hepatic IR, suggesting that targeting ETNPPL might represent a potential approach for T2DM therapy.

Myo1b Promotes Premature Endothelial Senescence and Dysfunction via Suppressing Autophagy: Implications for Vascular Aging.

Endothelial cell (EC) senescence characterized by an irreversible growth arrest leading to endothelial dysfunction has been implicated in vascular aging and aging-associated cardiovascular diseases. Autophagy plays a crucial role in the modulation of cellular senescence. Our previous showed that myosin 1b (Myo1b), one family of nonfilamentous class-1 myosin, was reported to be involved in the modulation of human smooth muscle cell senescence. However, the role of Myo1b in the modulation of EC senescence with links to autophagy has yet to be elucidated. In this study, we sought to explore the role of Myo1b in endothelial senescence and further elucidate the underlying mechanisms. Here, we show prominent upregulation of Myo1b in senescent ECs in comparison with nonsenescence ECs in both mRNA and protein expression levels. Silencing Myo1b in senescent cells ameliorates endothelial dysfunctions and reverses endothelial senescence phenotypic changes such as senescence-associated-ß-galactosidase activity, cyclin-dependent kinase inhibitor p21WAF1, expression of vascular adhesion molecule-1 (VCAM1) and intercellular adhesion molecule-1 (ICAM1), and the senescence-associated cytokines. In contrast, in nonsenescent cells, overexpressing Myo1b promotes endothelial senescence and suppresses autophagy through the impairment of autophagosome and lysosome fusion. The interaction between Myo1b and LRRK2 through Myo1b tail domain promotes intracellular calcium elevation, which results in the inhibition of autophagic flux. In vitro and in vivo aging models, Myo1b knockdown in senescent ECs and wild type-aged mice is able to enhance autophagy and ameliorate aging-associated endothelial dysfunction. Taken together, our studies reveal a new function for Myo1b, that is, to couple LRRK2 assembly to promote an increase in intracellular calcium level, which impairs the autophagosome-lysosome fusion, and ultimately the promotion of EC senescence and vascular aging.

Arginase: Biological and Therapeutic Implications in Diabetes Mellitus and Its Complications.

Arginase is a ubiquitous enzyme in the urea cycle (UC) that hydrolyzes L-arginine to urea and L-ornithine. Two mammalian arginase isoforms, arginase1 (ARG1) and arginase2 (ARG2), play a vital role in the regulation of ß-cell functions, insulin resistance (IR), and vascular complications via modulating L-arginine metabolism, nitric oxide (NO) production, and inflammatory responses as well as oxidative stress. Basic and clinical studies reveal that abnormal alterations of arginase expression and activity are strongly associated with the onset and development of diabetes mellitus (DM) and its complications. As a result, targeting arginase may be a novel and promising approach for DM treatment. An increasing number of arginase inhibitors, including chemical and natural inhibitors, have been developed and shown to protect against the development of DM and its complications. In this review, we discuss the fundamental features of arginase. Next, the regulatory roles and underlying mechanisms of arginase in the pathogenesis and progression of DM and its complications are explored. Furthermore, we review the development and discuss the challenges of arginase inhibitors in treating DM and its related pathologies.

Arginase: shedding light on the mechanisms and opportunities in cardiovascular diseases.

Arginase, a binuclear manganese metalloenzyme in the urea, catalyzes the hydrolysis of L-arginine to urea and L-ornithine. Both isoforms, arginase 1 and arginase 2 perform significant roles in the regulation of cellular functions in cardiovascular system, such as senescence, apoptosis, proliferation, inflammation, and autophagy, via a variety of mechanisms, including regulating L-arginine metabolism and activating multiple signal pathways. Furthermore, abnormal arginase activity contributes to the initiation and progression of a variety of CVDs. Therefore, targeting arginase may be a novel and promising approach for CVDs treatment. In this review, we give a comprehensive overview of the physiological and biological roles of arginase in a variety of CVDs, revealing the underlying mechanisms of arginase mediating vascular and cardiac function, as well as shedding light on the novel and promising therapeutic approaches for CVDs therapy in individuals.

Tongxinluo-pretreated mesenchymal stem cells facilitate cardiac repair via exosomal transfer of miR-146a-5p targeting IRAK1/NF-κB p65 pathway.

BACKGROUND: Bone marrow cells (BMCs), especially mesenchymal stem cells (MSCs), have shown attractive application prospects in acute myocardial infarction (AMI). However, the weak efficacy becomes their main limitation in clinical translation. Based on the anti-inflammation and anti-apoptosis effects of a Chinese medicine-Tongxinluo (TXL), we aimed to explore the effects of TXL-pretreated MSCs (MSCsTXL) in enhancing cardiac repair and further investigated the underlying mechanism. METHODS: MSCsTXL or MSCs and the derived exosomes (MSCsTXL-exo or MSCs-exo) were collected and injected into the infarct zone of rat hearts. In vivo, the anti-apoptotic and anti-inflammation effects, and cardiac functional and histological recovery were evaluated. In vitro, the apoptosis was evaluated by western blotting and flow cytometry. miRNA sequencing was utilized to identify the significant differentially expressed miRNAs between MSCsTXL-exo and MSCs-exo, and the miRNA mimics and inhibitors were applied to explore the specific mechanism. RESULTS: Compared to MSCs, MSCsTXL enhanced cardiac repair with reduced cardiomyocytes apoptosis and inflammation at the early stage of AMI and significantly improved left ventricular ejection fraction (LVEF) with reduced infarct size in an exosome-dependent way. Similarly, MSCsTXL-exo exerted superior therapeutic effects in anti-apoptosis and anti-inflammation, as well as improving LVEF and reducing infarct size compared to MSCs-exo. Further exosomal miRNA analysis demonstrated that miR-146a-5p was the candidate effector of the superior effects of MSCsTXL-exo. Besides, miR-146a-5p targeted and decreased IRAK1, which inhibited the nuclear translocation of NF-κB p65 thus protecting H9C2 cells from hypoxia injury. CONCLUSIONS: This study suggested that MSCsTXL markedly facilitated cardiac repair via a new mechanism of the exosomal transfer of miR-146a-5p targeting IRAK1/NF-κB p65 pathway, which has great potential for clinical translation.

Isolation and Identification of Porcine Bone Marrow Mesenchymal Stem Cells and their Derived Extracellular Vesicles.

With the development of stem cell therapy in translational research and regenerative medicine, bone marrow mesenchymal stem cells (BM-MSCs), as a kind of pluripotent stem cells, are favored for their instant availability and proven safety. It has been reported that transplantation of BM-MSCs is of great benefit to repairing injured tissues in various diseases, which might be related to modulating the immune and inflammatory responses via paracrine mechanisms. Extracellular vesicles (EVs), featuring a double-layer lipid membrane structure, are considered to be the main mediators of the paracrine effects of stem cells. Recognized for their crucial roles in cell communication and epigenetic regulation, EVs have already been applied in vivo for immunotherapy. However, similar to its maternal cells, most of the studies on the efficacy of transplantation of EVs still remain at the level of small animals, which is not enough to provide essential evidence for clinical translation. Here, we use density-gradient centrifugation to isolate bone marrow cells (BMC) from porcine bone marrow at first, and get porcine BM-MSCs (pBM-MSCs) by cell culture subsequently, identified by the results of observation under the microscope, induced differentiation assay, and flow cytometry. Furthermore, we isolate EVs derived from pBM-MSCs in cell supernatant by ultracentrifugation, proved by the techniques of transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and western blotting successfully. Overall, pBM-MSCs and their derived EVs can be isolated and identified effectively by the following protocols, which might be widely used in pre-clinical studies on the transplantation efficacy of BM-MSCs and their derived EVs.

Arginase: An emerging and promising therapeutic target for cancer treatment.

Arginase is a key hydrolase in the urea cycle that hydrolyses L-arginine to urea and L-ornithine. Increasing number of studies in recent years demonstrate that two mammalian arginase isoforms, arginase 1 (ARG1) and arginase 2 (ARG2), were aberrantly upregulated in various types of cancers, and played crucial roles in the regulation of tumor growth and metastasis through various mechanisms such as regulating L-arginine metabolism, influencing tumor immune microenvironment, etc. Thus, arginase receives increasing focus as an attractive target for cancer therapy. In this review, we provide a comprehensive overview of the physiological and biological roles of arginase in a variety of cancers, and shed light on the underlying mechanisms of arginase mediating cancer cells growth and development, as well as summarize the recent clinical research advances of targeting arginase for cancer therapy.