Ox-LDL promotes M1-like polarization of macrophages through the miR-21-5p/SKP2/EP300 pathway.

Oxidized low-density lipoprotein (ox-LDL) mediated inflammatory damage, which possibly induces atherosclerosis (AS); however, the role of miRNA in this process has rarely been reported. In this paper, we study the ox-LDL-related endothelial cell damage and changes of macrophages. The bioinformatics method was used to analyze the expression changes of miRNA in AS patients, luciferase assay was used to study the interaction of protein and miRNA, and co-IP and ubiquitination experiments were used to analyze protein interaction. Flow cytometry was used to detect the polarization of macrophages. Database analysis showed that the expression of miR-21-5p was upregulated in AS patients. Luciferase assay showed that miR-21-5p can bind to SKP2 and subsequently influence ubiquitination of EP300. Overexpression of EP300 strengthens the HMGB1-induced acetylation and subsequently mediates the dissociation of HMGB1 from SIRT1, and thus HMGB1 could be secreted outside the cell. The HMGB1 released from endothelial cells can promote macrophage M1 polarization. This study shows that ox-LDL activates the SKP2/EP300 pathway through promoting upregulation of miR-21-5p, thereby acetylating and secreting HMGB1 outside the endothelium, subsequently enhancing macrophage polarization to further stabilize the inflammation situation.

Knockdown circ_0040414 inhibits inflammation, apoptosis and promotes the proliferation of cardiomyocytes via miR-186-5p/PTEN/AKT axis in chronic heart failure.

Previous studies have shown that circ_0040414 is highly expressed in the blood of patients with heart failure (HF), which suggests that circ_0040414 is associated with heart failure (HF). However, the functional involvement of circ_0040414 in HF and its potential mechanism remains unclear. Consistent with previous studies, our study showed that the expression of circ_0040414 in the peripheral blood of patients with chronic heart failure (CHF) was significantly higher than that of healthy control, which indicated that circ_0040414 could be used as a diagnostic biomarker in patients with CHF. In cardiomyocytes, circ_0040414 increased the level of proapoptotic proteins Bax, cleaved-caspase 3 and reduced the expression of antiapoptotic protein Bcl-2. It also promoted inflammatory factors IL-6, TNF-α, and IL-ß, but inhibited cell proliferation. In terms of mechanism, circ_0040414 upregulated the expression of phosphatase and tensin homolog (PTEN) through sponging miR-186-5p to inhibit AKT signaling activity. Our study uncovered a novel role and the mechanism of circ_0040414 in controlling CHF, enriched the molecular regulatory network in CHF, and may provide a possible strategy for the treatment of CHF.

Functional polymorphism of lncRNA MALAT1 contributes to pulmonary arterial hypertension susceptibility in Chinese people.

BACKGROUND: The long noncoding RNAs (lncRNAs) have gradually been reported to be an important class of RNAs with pivotal roles in regulation of gene expression, and thus are involved in multitudinous human complex diseases. However, the biological functions and precise mechanisms of the majority of lncRNAs are still poorly understood. METHODS: In the study, we tested genomic variations in lncRNA-metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) loci, and their potentially functional correlationship with pulmonary arterial hypertension (PAH) susceptibility based on a case-control study with a total of 587 PAH patients and 736 healthy controls in southern Chinese. RESULTS: We found that the rs619586A>G single nucleotide polymorphism (SNP) was significantly associated with PAH risk. The carriers with G variant genotypes had a decreased risk of PAH (odds ratio [OR]=0.69, 95% confidence interval [CI]=0.53-0.90, p=0.007) compared to the rs619586AA genotype. Further functional experiments indicated that the alteration from rs619586A to G in MALAT1 could directly upregulate X box-binding protein 1 (XBP1) expression via functioning as the competing endogenous RNA (ceRNA) for miR-214, and consequentially inhibiting the vascular endothelial cells proliferation and migration in vitro by shortening S-M phase transition. CONCLUSIONS: Taken together, our findings propose that functional polymorphism rs619586A>G in MALAT1 gene plays an important role in PAH pathogenesis and may serve as a potential indicator for PAH susceptibility.

Nephrolithiasis and Osteomalacia associated with adefovir-induced Fanconi syndrome in a patient with hepatitis B.

BACKGROUND: An increasing number of case reports suggest that acquired renal Fanconi syndrome may be associated with prolonged use of adefovir against hepatitis B virus. Renal Fanconi syndrome is an uncommon disease, and its complication with nephrolithiasis is quite rare. Herein, we report a rare coexistence of nephrolithiasis and acquired renal Fanconi syndrome in a chronic hepatitis B-positive patient with prolonged adefovir therapy. CASE PRESENTATION: The patient presented with osteomalacia and nephrolithiasis. Consequently, extracorporeal shock-wave lithotripsy and left double-J ureteral stent insertion were considered for obstructive nephropathy, which was caused by nephrolithiasis. However, osteomalacia had been misdiagnosed as osteoporosis before admission to our hospital. On admission, a complexity of multiple fractures, hypophosphataemia, glycosuria without hyperglycaemia and non-anion-gap metabolic acidosis indicated a diagnosis of acquired renal Fanconi syndrome induced by adefovir. After switching from adefovir to entecavir, the patient's symptoms and laboratory findings improved significantly. CONCLUSIONS: The mechanism responsible for nephrolithiasis in renal Fanconi syndrome is still unclear. We recommend regularly monitoring renal function and serum calcium and serum phosphate to prevent renal Fanconi syndrome during the prolonged use of adefovir for hepatitis B virus.

CagA-positive Helicobacter pylori strains enhanced coronary atherosclerosis by increasing serum OxLDL and HsCRP in patients with coronary heart disease.

BACKGROUND: The role of infection in the pathogenesis of atherosclerosis is still a matter of debate. AIMS: This study aimed to investigate the effect of CagA-positive Helicobacter pylori (H. pylori) strains infection on coronary atherosclerosis in patients with coronary heart disease and to elucidate how cytotoxin-associated gene A (CagA)-positive H. pylori strains infections were involved in coronary heart disease by examining the levels of serum lipid, high-sensitivity C-reactive protein (hsCRP) and oxidized low-density protein (oxLDL). METHODS: Recruited for this study were 159 patients with coronary heart disease. The severity of coronary heart disease was estimated by calculating the Gensini score. Serum oxLDL and hsCRP were examined in all subjects. Current H. pylori infection was determined in all participants by means of a modified (13C) urea breath test (>200 dpm classified as positive). IgG antibodies against CagA protein were analyzed by enzyme immunoassays. Antibody titers against CagA (≥8 U/ml) were classified as positive. All subjects were divided into three groups, including an uninfected group (n=30), an H. pylori +CagA- group (n=69), and an H. pylori +CagA+ group (n=60). RESULTS: Significant differences were found among the three groups in levels of total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, serum hsCRP, oxLDL, and severity of coronary atherosclerosis (p<0.05). The levels of total cholesterol, LDL, apolipoprotein B, serum hsCRP, oxLDL were significantly elevated and the severity of coronary atherosclerosis was significantly increased in H. pylori +CagA+ group (p<0.05). CONCLUSIONS: More serious coronary atherosclerosis was observed in CHD patients with H. pylori +CagA+ infection. H. pylori +CagA+ infection might be involved in coronary atherosclerosis by modifying serum lipids, enhancing LDL oxidation, and activating the inflammatory responses.

VEGF Promoter Polymorphism Confers an Increased Risk of Pulmonary Arterial Hypertension in a Chinese Population.

PURPOSE: Evidence on the contribution of genes to the hereditary predisposition to pulmonary arterial hypertension (PAH) is limited. MATERIALS AND METHODS: In this study, we hypothesized that single nucleotide variants in vascular endothelial growth factor (VEGF) gene may alter gene function and expression and may be associated with PAH risk. Five putatively functional loci (rs699947C>A and rs833061T>C in the promoter, rs3025040C>T, rs10434G>A and rs3025053G>A in the 3'-UTR) in the VEGF gene were genotyped and analyzed in a retrospective study of 587 patients with PAH and 736 healthy subjects from southern China. RESULTS: We found that the rs833061T>C polymorphism was significantly associated with PAH risk, while the other single nucleotide polymorphisms were not. Compared to carriers with TT genotype, those with rs833061C variant genotype (CT/CC) had an increased risk of PAH (odds ratio=1.47, 95% confidence interval=1.18-1.83, p=0.001). Functional assays indicated that CT/CC variant genotype had significantly higher mRNA levels of VEGF in peripheral blood mononuclear cells than TT genotype (p=0.021). Luciferase reporter assay indicated that having a C allele conferred a significantly higher transcription activity than that with a T allele. CONCLUSION: Our findings suggest that the functional polymorphism rs833061T>C in VEGF gene promoter modulates VEGF expression and may be a valuable biomarker for predicting PAH susceptibility.

Hydrogen gas protects against serum and glucose deprivation­induced myocardial injury in H9c2 cells through activation of the NF­E2­related factor 2/heme oxygenase 1 signaling pathway.

Ischemia or hypoxia­induced myocardial injury is closely associated with oxidative stress. Scavenging free radicals and/or enhancing endogenous antioxidative defense systems may be beneficial for the impediment of myocardial ischemic injury. Hydrogen (H2) gas, as a water­ and lipid­soluble small molecule, is not only able to selectively eliminate hydroxyl (·OH) free radicals, but also to enhance endogenous antioxidative defense systems in rat lungs and arabidopsis plants. However, thus far, it has remained elusive whether H2 gas protects cardiomyocytes through enhancement of endogenous antioxidative defense systems. In the present study, the cardioprotective effect of H2 gas against ischemic or hypoxic injury was investigated, along with the underlying molecular mechanisms. H9c2 cardiomyoblasts (H9c2 cells) were treated in vitro with a chemical hypoxia inducer, cobalt chloride (CoCl2), to imitate hypoxia, or by serum and glucose deprivation (SGD) to imitate ischemia. Cell viability and intracellular ·OH free radicals were assessed. The role of an endogenous antioxidative defense system, the NF­E2­related factor 2 (Nrf2)/heme oxygenase 1 (HO­1) signaling pathway, was evaluated. The findings revealed that treatment with CoCl2 or SGD markedly reduced cell viability in H9c2 cells. H2 gas­rich medium protected against cell injury induced by SGD, but not that induced by CoCl2. When the cells were exposed to SGD, levels of intracellular ·OH free radicals were markedly increased; this was mitigated by H2 gas­rich medium. Exposure of the cells to SGD also resulted in significant increases in HO­1 expression and nuclear Nrf2 levels, and the HO­1 inhibitor ZnPP IX and the Nrf2 inhibitor brusatol aggravated SGD­induced cellular injury. H2 gas­rich medium enhanced SGD­induced upregulation of HO­1 and Nrf2, and the HO­1 or Nrf2 inhibition partially suppressed H2 gas­induced cardioprotection. Furthermore, following genetic silencing of Nrf2 by RNA interference, the effects of H2 gas on the induction of HO­1 and cardioprotection were markedly reduced. In conclusion, H2 gas protected cardiomyocytes from ischemia­induced myocardial injury through elimination of ·OH free radicals and also through activation of the Nrf2/HO­1 signaling pathway.

Aging impairs the angiogenic response to ischemic injury and the activity of implanted cells: combined consequences for cell therapy in older recipients.

OBJECTIVE: Cell therapy has received much attention for its potential to regenerate ischemic organs, but initial clinical trials in aged patients did not replicate the dramatic benefits recorded in preclinical studies with young animals. This study was designed to improve our understanding of age-related changes in the response to ischemic injury and the regenerative capacity of implanted cells in the context of cell therapy for older recipients. METHODS AND RESULTS: Restoration of regional perfusion after hind limb femoral artery ligation was impaired (P < .05) in old (vs young) rats, reflecting approximately 50% reductions in circulating endothelial progenitor cells and the release of vascular endothelial growth factor/basic fibroblast growth factor. Bone marrow stromal cells from young or old donors implanted into the ischemic hind limbs of young or old rats restored regional perfusion. Specifically, we documented significantly greater (P < .05) angiogenic potential in young (vs old) donor cells when recipient age was controlled and greater (P < .05) regenerative responses in young (vs old) recipients when donor cell age was controlled. Contributing to these differences were significantly greater survival in young (vs old) donor cells (in vitro and after implantation) and about 2-fold more production of vascular endothelial growth factor/basic fibroblast growth factor and mobilization of endogenous endothelial progenitor cells in young (vs old) rats in response to ischemia. CONCLUSIONS: The outcome of cell therapy in older recipients is determined by a combination of age effects on the donor cells and on the recipients' endogenous responses. Donor cell age and recipient age are equally important contributors to the outcome of cell therapy; thus, novel biointerventions will need to target both components of the process.

Improvement in cardiac function after bone marrow cell thearpy is associated with an increase in myocardial inflammation.

The mechanisms for the beneficial impact of bone marrow cell (BMC) therapy after myocardial infarction (MI) are ill defined. We hypothesized that the implanted cells improve function by attenuating post-MI inflammation and repair. In mice, 3 x 10(5) fresh BMCs were implanted immediately after coronary ligation. Cardiac function was evaluated over time. Inflammatory cytokines and cells were measured, and their impacts on the (myo)fibroblastic repair response, angiogenesis, and scar formation were determined. All differences below had P values of <0.05. BMC implantation reduced the decline in fractional shortening and ventricular dilation. Invasive hemodynamics confirmed a difference in systolic function at day 7 and diastolic function at day 28 favoring the BMC group. Interestingly, BMC implantation caused a 1.6-fold increase in the number of macrophages infiltrating the infarct but did not affect neutrophils. This increase was associated with a 1.9-fold higher myocardial TNF-alpha level. The heightened inflammatory response was associated with a 1.4-fold induction of transforming growth factor-beta and a 1.3-fold induction of basic fibroblast growth factor. These changes resulted in a 1.6-fold increase in alpha-smooth muscle actin and a 1.9-fold increase in total discoidin domain receptor 2-expressing cells in the BMC group. These two markers are expressed by cardiac (myo)fibroblasts. Capillary density in the border zone increased 2.0-fold. Consistent with a more robust repair-mediated scar "contracture," the final scar size was 0.7-fold smaller in the BMC group. In conclusion, after MI, BMC therapy induced a more robust inflammatory response that improved the "priming" of the (myo)fibroblast repair phase. Enhancing this response may further improve the beneficial impact of cellular therapy.