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Adiponectin (APN) exerts its metabolic regulation largely through AMP-dependent protein kinase (AMPK). However, the role of AMPK in APN's antiapoptotic effect in ischemic-reperfused (I/R) adult cardiomyocytes remains incompletely understood. The present study was designed to determine the involvement of AMPK in the antiapoptotic signaling of APN. Cardiomyocytes from adult male mice overexpressing a dominant-negative α2-subunit of AMPK (AMPK-DN) or wild-type (WT) littermates were subjected to simulated hR (SI/R) and pretreated with 2 μg/ml globular domain of APN (gAPN) or vehicle. SI/R-induced cardiomyocyte apoptosis was modestly increased in AMPK-DN cardiomyocytes (P < 0.05). Treatment with gAPN significantly reduced SI/R-induced apoptosis in WT cardiomyocytes as well as in AMPK-DN cardiomyocytes, indicating that the antiapoptotic effect of gAPN is partially AMPK independent. Furthermore, gAPN-induced endothelial nitric oxide synthase (eNOS) phosphorylation was significantly reduced in AMPK-DN cardiomyocytes, suggesting that the APN-eNOS signaling axis is impaired in AMPK-DN cardiomyocytes. Additional experiments demonstrated that treatment of AMPK-DN cardiomyocytes with gAPN reduced SI/R-induced NADPH oxidase overexpression, decreased superoxide generation, and blocked peroxynitrite formation to the same extent as that observed in WT cardiomyocytes. Collectively, our present study demonstrated that although the metabolic and eNOS activation effect of APN is largely mediated by AMPK, the superoxide-suppressing effect of APN is not mediated by AMPK, and this AMPK-independent antioxidant property of APN increased nitric oxide bioavailability and exerted significant antiapoptotic effect. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus exacerbates myocardial ischemia/reperfusion (MI/R) injury by incompletely understood mechanisms. Adipocyte dysfunction contributes to remote organ injury. However, the molecular mechanisms linking dysfunctional adipocytes to increased MI/R injury remain unidentified. The current study attempted to clarify whether and how small extracellular vesicles (sEV) may mediate pathological communication between diabetic adipocytes and cardiomyocytes, exacerbating MI/R injury.Methods: Adult male mice were fed a normal or a high-fat diet for 12 weeks. sEV (from diabetic serum, diabetic adipocytes, or high glucose/high lipid-challenged nondiabetic adipocytes) were injected intramyocardially distal of coronary ligation. Animals were subjected to MI/R 48 hours after injection.Results: Intramyocardial injection of diabetic serum sEV in the nondiabetic heart significantly exacerbated MI/R injury, as evidenced by poorer cardiac function recovery, larger infarct size, and greater cardiomyocyte apoptosis. Similarly, intramyocardial or systemic administration of diabetic adipocyte sEV or high glucose/high lipid-challenged nondiabetic adipocyte sEV significantly exacerbated MI/R injury. Diabetic epididymal fat transplantation significantly increased MI/R injury in nondiabetic mice, whereas administration of a sEV biogenesis inhibitor significantly mitigated MI/R injury in diabetic mice. A mechanistic investigation identified that miR-130b-3p is a common molecule significantly increased in diabetic serum sEV, diabetic adipocyte sEV, and high glucose/high lipid-challenged nondiabetic adipocyte sEV. Mature (but not primary) miR-130b-3p was significantly increased in the diabetic and nondiabetic heart subjected to diabetic sEV injection. Whereas intramyocardial injection of a miR-130b-3p mimic significantly exacerbated MI/R injury in nondiabetic mice, miR-130b-3p inhibitors significantly attenuated MI/R injury in diabetic mice. Molecular studies identified AMPKα1/α2, Birc6, and Ucp3 as direct downstream targets of miR-130b-3p. Overexpression of these molecules (particularly AMPKα2) reversed miR-130b-3p induced proapoptotic/cardiac harmful effect. Finally, miR-130b-3p levels were significantly increased in plasma sEV from patients with type 2 diabetes mellitus. Incubation of cardiomyocytes with diabetic patient sEV significantly exacerbated ischemic injury, an effect blocked by miR-130b-3p inhibitor.Conclusions: We demonstrate for the first time that miR-130b-3p enrichment in dysfunctional adipocyte-derived sEV, and its suppression of multiple antiapoptotic/cardioprotective molecules in cardiomyocytes, is a novel mechanism exacerbating MI/R injury in the diabetic heart. Targeting miR-130b-3p mediated pathological communication between dysfunctional adipocytes and cardiomyocytes may be a novel strategy attenuating diabetic exacerbation of MI/R injury. [ABSTRACT FROM AUTHOR]

Abstract Withaferin A (WFA), a withanolide derived from medicinal plant Withania somnifera , possesses anti-tumorigenic and immunomodulatory activities against various cancer cells. However, the role of WFA in myocardial ischemia reperfusion (MI/R) injury remains unclear. In the present study, we determined whether WFA may regulate cardiac ischemia reperfusion injury and elucidate the underlying mechanisms. We demonstrated that WFA enhanced H9c2 cells survival ability against simulated ischemia/reperfusion (SI/R) or hydrogen peroxide (H 2 O 2)-induced cell apoptosis. In addition, the enhanced oxidative stress induced by SI/R was inhibited by WFA. Among the multiple antioxidant molecules determined, antioxidants SOD2, SOD3, Prdx-1 was obviously upregulated by WFA. When Akt inhibitor IV was administrated, WFA's suppression effect on oxidative stress was obviously abolished. Additional experiments demonstrated that WFA successfully inhibited H 2 O 2 induced upregulation of SOD2, SOD3, and Prdx-1, ameliorated cardiomyocyte caspase-3 activity via an Akt dependent manner. Collectively, these results support the therapeutic potential of WFA against cardiac ischemia reperfusion injury and highlight the application of WFA in cardiovascular diseases holding great promise for the future. [ABSTRACT FROM AUTHOR]

Natural flavonoids from plants have been demonstrated to possess promising chemopreventive activities against various diseases. 7-{4-[Bis-(2-hydroxy-ethyl)-amino]-butoxy}-5-hydroxy-8-methoxy-2-phenyl-chromen-4-one (V8), a newly synthesized derivative of wogonin may have antioxidant, antiviral, anti-inflammatory and anti-tumor potentials as wogonin. Based on the recent findings of V8, the anti-tumor activities and fundamental mechanisms by which V8 inhibits growth of hepatocellular carcinoma were further investigated in this study. After the treatment of V8, a significant inhibition of HepG2 cell proliferation was observed in a dose-dependent manner with the IC value of 23 μM using MTT assay. The exposure to V8 also resulted in apoptosis induction and an accumulation of ROS and Ca. Meanwhile, a release of cytochrome c (Cyt-c), activation of BH-3 only proteins and Bax, decrease in mitochondrial membrane potential ΔΨ, as well as a suppression of Bcl-2, pro-caspase9 and pro-caspase3 expression were shown. Moreover, knocking down CHOP partly decreased the effect of V8-mediated apoptosis and activation of GRP78, p-PERK, p-eIF2α, ATF4 and CHOP modulated ER stress triggered by V8. In vivo, V8 inhibited the transplanted mice H22 liver carcinomas in a dose-dependent manner. Compared with wogonin, V8 exhibited stronger anti-proliferative effects both in vitro and in vivo. The underlying mechanism of activating PERK-eIF2α-ATF4 pathway by which V8 induces apoptosis was verified once again in vivo. The apoptosis induction via the mitochondrial pathway by modulating the ROS-mediated ER signaling pathway might serve to provide support for further studies of V8 as a possible anticancer drug in the clinical treatment of cancer. [ABSTRACT FROM AUTHOR]

Evidence suggests Ginsenoside Rd (GSRd), a biologically active extract from the medical plant Panax Ginseng, exerts antioxidant effect, decreasing reactive oxygen species (ROS) formation. Current study determined the effect of GSRd on myocardial ischemia/reperfusion (MI/R) injury (a pathological condition where ROS production is significantly increased) and investigated the underlying mechanisms. The current study utilized an in vivo rat model of MI/R injury and an in vitro neonatal rat cardiomyocyte (NRC) model of simulated ischemia/reperfusion (SI/R) injury. Infarct size was measured by Evans blue/TTC double staining. NRC injury was determined by MTT and lactate dehydrogenase (LDH) leakage assay. ROS accumulation and apoptosis were assessed by flow cytometry. Mitochondrial membrane potential (MMP) was determined by 5, 5′, 6, 6′-tetrachloro-1, 1′, 3, 3′-tetrathylbenzimidazol carbocyanine iodide (JC-1). Cytosolic translocation of mitochondrial cytochrome c and expression of caspase-9, caspase-3, Bcl-2 family proteins, and phosphorylated Akt and GSK-3β were determined by western blot. Pretreatment with GSRd (50 mg/kg) significantly augmented rat cardiac function, as evidenced by increased left ventricular ejection fraction (LVEF) and ±dP/dt. GSRd reduced myocardial infarct size, apoptotic cell death, and blood creatine kinase/lactate dehydrogenase levels after MI/R. In NRCs, GSRd (10 µM) inhibited SI/R-induced ROS generation (P<0.01), decreased cellular apoptosis, stabilized the mitochondrial membrane potential (MMP), and attenuated cytosolic translocation of mitochondrial cytochrome c. GSRd inhibited activation of caspase-9 and caspase-3, increased the phosphorylated Akt and GSK-3β, and increased the Bcl-2/Bax ratio. Together, these data demonstrate GSRd mediated cardioprotective effect against MI/R–induced apoptosis via a mitochondrial-dependent apoptotic pathway. [ABSTRACT FROM AUTHOR]

Atherosclerotic vascular disease remains the principal cause of death and disability among patients with type 2 diabetes. Unfortunately, the problem is not adequately resolved by therapeutic strategies with currently available drugs or approaches that solely focus on optimal glycemic control. To identify the key contributors and better understand the mechanism of diabetic atherosclerotic vascular disease, we aimed to elucidate the key genetic characteristics and pathological pathways in atherosclerotic vascular disease through nonbiased bioinformatics analysis and subsequent experimental demonstration and exploration in diabetic atherosclerotic vascular disease. Sixty-eight upregulated and 23 downregulated genes were identified from the analysis of gene expression profiles (GSE30169 and GSE6584). A comprehensive bioinformatic assay further identified that ferroptosis, a new type of programmed cell death and HMOX1 (a gene that encodes heme oxygenase), were vital factors in atherosclerotic vascular disease. We further demonstrated that diabetes significantly increased ferroptosis and HMOX1 levels compared to normal controls. Importantly, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively attenuated diabetic atherosclerosis, suggesting the causative role of ferroptosis in diabetic atherosclerosis development. At the cellular level, Fer-1 ameliorated high glucose high lipid-induced lipid peroxidation and downregulated ROS production. More importantly, HMOX1 knockdown attenuated Fe2+ overload, reduced iron content and ROS, and alleviated lipid peroxidation, which led to a reduction in ferroptosis in diabetic human endothelial cells. We demonstrated that HMOX1 upregulation is responsible for the increased ferroptosis in diabetic atherosclerosis development, suggesting that HMOX1 may serve as a potential therapeutic or drug development target for diabetic atherosclerosis. [ABSTRACT FROM AUTHOR]

Fluoride exposure could damage the structure of kidney, induce the nephron-toxicity by activating autophagy, apoptosis and glucolipid metabolism pathways suggesting that fluorine exposure poses a risk of poisoning. This is the first study to reveal regulation mechanism of autophagy and apoptosis associated with glucolipid metabolism in NaF-induced nephron-toxicity, which provide important reference for environmental toxicology. [Display omitted] Fluoride is one of the most widely distributed elements in nature, while some fluorine-containing compounds are toxic to several vertebrates at certain levels. The current study was performed to evaluate the nephrotoxic effects of fluoride exposure in ducks. The results showed that the renal index was decreased in NaF group, and fluoride exposure significantly decreased the levels of serum Albumin, Glucose, Total cholesterol, Urea, protein and Triglycerides, confirming that NaF exhibited adverse effects on the kidney. The overall structure of renal cells showed damage with the signs of nuclelytic, vacuolar degeneration, atrophy, renal cystic cavity widening after fluoride induction. Renal vascular growth was impaired as the expression of VEGF and HIF-1α decreased (p > 0.05). More importantly, autophagy and apoptosis levels of CYT C, LC3, p62, Beclin, M-TOR, Bax and Caspase-3 were increased (p < 0.05) in the NaF treated group. Interestingly, our results showed that Phosphatidylethanolamine (PE) and Phosphatidylcholine (PC) activated the M-TOR autophagy pathway. Meanwhile, the PE acted on Atg5/ LC3 autophagy factor, followed by the auto-phagosome generation and activation of cell autophagy. These results indicate that NaF exposure to duck induced nephron-toxicity by activating autophagy, apoptosis and glucolipid metabolism pathways, which suggest that fluorine exposure poses a risk of poisoning. [ABSTRACT FROM AUTHOR]

Abstract: Androgens can increase susceptibility toward numerous parasitic infections as well as modulate apoptosis of immune cells. According to the current view, androgens mediate immune cell activities not only through classical intracellular androgen receptors (AR), but also through membrane receptors on the cell surface. Here, using murine bone marrow-derived macrophages (BMMs), we examined the influence of testosterone on Leishmania donovani infection and cell viability in vitro as well as the possible mechanisms. Our data demonstrated that testosterone directly increased intramacrophage infection by L. donovani. In addition, testosterone decreased cell viability by way of apoptosis, accompanied by increased Fas, FasL, and Caspase-8 expression. However, these effects of testosterone could not be associated with the classical AR in BMMs since AR was not detectable using different experimental techniques. Instead, it was found that testosterone could bind to the surface of BMMs by the use of an impermeable testosterone-BSA-FITC in confocal laser scanning microscopy and flow cytometry. Collectively, our data indicated that the influence of testosterone on L. donovani infection and viability of BMMs was mediated through the binding sites of testosterone on cell surfaces, which provided a novel mode of direct action of testosterone on AR-free BMMs. [Copyright &y& Elsevier]

Since an outbreak of vaping-related deaths in the US has been reported as a public health crisis, the cardiovascular safety of nicotine nowadays receives increasing attention due to use of tobacco cigarette alternatives, such as electronic cigarettes. However, whether and how nicotine contributes to cardiac detrimental effects are in great controversy, especially less understood in young adult population. We report that chronic nicotine exposure, a major component of Electronic cigarettes, resulted in directly inhibited cardiomyocytes viability, increased cardiac fibrosis, and markedly suppressed cardiac function compared with sham. Gene array combined with bioinformatics analysis identified cardiac apoptosis and mitophagy were the key signals responsible for nicotine induced cardiac detrimental effect. Mechanistically, nicotine exposure markedly increased cleaved Caspase 3 and cleaved Caspase 9 indicating the involvement of intrinsic apoptotic pathway (mitochondrial cell death pathway). Meanwhile, nicotine-induced ROS outbreak promoted lysomal alkalization, furthermore blocked mitophagic degradation, thereby disrupted mitophagic flux promoted mitochondrial cell death cascade. Taken together, these findings indicate that nicotine confers cardiotoxicity via ROS-induced mitophagic flux blockage and provide the first demonstration of a causative link between nicotine and cardiac toxicity in young adult rat which may suggest nicotine induces cardiomyocytes impairment leading to cardiotoxicity in young adult population. [ABSTRACT FROM AUTHOR]

Background: C1q/tumor necrosis factor-related protein-9 (CTRP9) is a newly identified adiponectin paralog with established metabolic regulatory properties. However, the role of CTRP9 in postmyocardial infarction remodeling remains completely unknown. This study determined whether CTRP9 may regulate cardiac remodeling after acute myocardial infarction (AMI) and elucidated the underlying mechanisms.Methods and Results: Male adult mice were subject to AMI by left anterior descending coronary artery ligation or sham surgery and treated with saline (vehicle) or globular CTRP9 via peritoneal implant osmotic pumps for 6 weeks. H9C2 cardiac cell lines were used in vitro for determining underlying mechanisms. Adipocyte CTRP9 expression and plasma CTRP9 levels were both significantly reduced after AMI. Compared with vehicle, CTRP9 treatment improved animal survival rate (P<0.05), restored cardiac function (P<0.05), attenuated adverse remodeling (P<0.01), and ameliorated cardiomyocyte apoptosis and fibrosis after AMI (P<0.01). Among the multiple antiremodeling molecules determined, AMP-activated protein kinase, protein kinase A (PKA), and Akt were significantly activated in CTRP9-treated heart. Surprisingly, CTRP9 remains cardioprotective in mice with cardiomyocyte-specific overexpression of a mutant AMP-activated protein kinase α2 subunit (AMPK-DN). Additional in vitro experiments demonstrated that administration of either PKA inhibitor or PKA-specific small interfering RNA virtually abolished the antiapoptotic effect of CTRP9 (P<0.05), whereas inhibition of Akt is less effective in blocking CTRP9 cardioprotection. Finally, CTRP9 phosphorylates BCL-2-associated agonist of cell death at its multiple antiapoptotic sites, an effect blocked by PKA inhibitor.Conclusions: We demonstrate that adipokine CTRP9 attenuates adverse cardiac remodeling after AMI, largely via a PKA-dependent pathway. [ABSTRACT FROM AUTHOR]