LncRNA PVT1 inhibits endothelial cells apoptosis in coronary heart disease through regulating MAPK1 expression via miR-532-3p.

Background: Coronary atherosclerotic heart disease (CAD) is an inflammatory vascular disease caused by atherosclerosis. Long non-coding RNAs are involved in the pathophysiological process of coronary heart disease. Here we investigated the regulatory effects of lncRNA PVT1 (PVT1) in human coronary artery endothelial cells (HCAECs).Methods: qRT-PCR and western blot were performed to detect gene and protein expressions. CCK-8, flow cytometry and wound healing assays were used to determine cell viability, apoptosis and migration of HCAECs. The binding relationship among miR-532-3p, PVT1 and MAPK1 was verified by dual luciferase reporter assay.Results: Overexpression of PVT1 markedly reduced cell apoptosis and increased cell proliferation and migration. However, miR-532-3p upregulation suppressed cell proliferation and migration and promoted apoptosis of HCAECs. PVT1 suppressed the expression of miR-532-3p via directly targeting miR-532-3p. And miR-532-3p overexpression abolished the effect of PVT1 upregulation on proliferation and apoptosis in HCAECs. Furthermore, MAPK1 acted as a target gene of miR-532-3p and miR-532-3p inhibited MAPK1 expression.Conclusion: PVT1 promoted MAPK1 expression by targeting miR-532-3p, thus inhibiting HCAECs apoptosis and promoting cell proliferation, suggesting PVT1 might have great potential as a therapeutic target for CAD.

Dietary fiber and SCFAs in the regulation of mucosal immunity.

Gut bacterial metabolites such as short-chain fatty acids (SCFAs) have important effects on immune cells and the gut. SCFAs derive from the fermentation of dietary fiber by gut commensal bacteria. Insufficient fiber intake thus compromises SCFA production and, as a consequence, the host's physiology (particularly immune functions). We propose that many Western diseases, including those associated with impaired mucosal responses such as food allergy and asthma, may be affected by insufficient fiber intake and reduced SCFA levels in the gut and blood. Insufficient fiber intake is 1 alternative, or contributor, on top of the "hygiene hypothesis" to the rise of Western lifestyle diseases, and the 2 ideas need to be reconciled. The mechanisms by which SCFAs influence immunity and gut homeostasis are varied; they include stimulation of G protein-coupled receptors (GPCRs), such as GPR43 or GPR41; inhibition of histone deacetylases (and hence, gene transcription changes); and induction of intracellular metabolic changes. SCFAs modulate at many different levels to alter mucosal homeostasis, including changes to gut epithelial integrity, increases in regulatory T-cell numbers and function, and decreased expression of numerous inflammatory cytokines. There is scope for preventing and/or treating diseases by using diets that alter SCFA levels.

Dysbiosis in imiquimod-induced psoriasis alters gut immunity and exacerbates colitis development.

Psoriasis has long been associated with inflammatory bowel disease (IBD); however, a causal link is yet to be established. Here, we demonstrate that imiquimod-induced psoriasis (IMQ-pso) in mice disrupts gut homeostasis, characterized by increased proportions of colonic CX3CR1hi macrophages, altered cytokine production, and bacterial dysbiosis. Gut microbiota from these mice produce higher levels of succinate, which induce de novo proliferation of CX3CR1hi macrophages ex vivo, while disrupted gut homeostasis primes IMQ-pso mice for more severe colitis with dextran sulfate sodium (DSS) challenge. These results demonstrate that changes in the gut environment in psoriasis lead to greater susceptibility to IBD in mice, suggesting a two-hit requirement, that is, psoriasis-induced altered gut homeostasis and a secondary environmental challenge. This may explain the increased prevalence of IBD in patients with psoriasis.

LncRNA MIAT knockdown alleviates oxygen-glucose deprivation­induced cardiomyocyte injury by regulating JAK2/STAT3 pathway via miR-181a-5p.

BACKGROUND: Coronary artery disease (CAD) is a common heart disease with high incidence and mortality. Myocardial ischemia is the main type of CAD, which negatively affects health worldwide. The aim of the present study was to investigate the function and mechanism of myocardial infarction-associated transcript (MIAT) in myocardial ischemia. METHODS: Human cardiomyocytes (HCM) were treated with oxygen-glucose deprivation (OGD) to set the in vitro model and mouse myocardial ischemia/reperfusion (I/R) was set for in vivo model. Cell viability and apoptosis were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, flow cytometry, and immunofluorescence analysis. Inflammatory cytokines levels were detected by enzyme-linked immunosorbent assay. Gene and protein expressions were identified by quantitative real time-polymerase chain reaction or Western blotting. The interaction of MIAT, miR-181a-5p, and janus kinase 2 (JAK2) was identified by dual-luciferase report assay. Mouse heart tissues histopathological condition were observed by hematoxylin and eosin assays. RESULTS: Expression of MIAT and JAK2 were increased in OGD-treated HCM and mice of I/R model group, and miR-181a-5p was decreased. MIAT silencing could reverse the OGD treatment induced cell proliferation inhibition, cleaved caspase-3 and Bcl2-associated X (Bax) levels increased, while those of B-cell lymphoma-2 (Bcl-2) and mitochondria's cyt-C decreased. Besides, MIAT knockdown attenuated the OGD-induced increase of tumor necrosis factor-α, interleukin (IL)-1ß, and IL-6 levels. Moreover, MIAT targeted miR-181a-5p to enhance the expression of JAK2 and signal Transducer and Activator of Transcription 3 (STAT3), and miR-181a-5p overexpression promoted proliferation, whereas it inhibited apoptosis in OGD-induced cardiomyocytes. Furthermore, the regulatory effects of MIAT knockdown in cell proliferation, apoptosis, and inflammatory injury was reversed by inhibition of miR-181a-5p or overexpression of JAK2 in OGD-treated HCM. Knockdown of MIAT reduced myocardial injury caused by I/R treatment in vivo. CONCLUSION: MIAT knockdown inhibited apoptosis and inflammation by regulating JAK2/STAT3 signaling pathway via targeting miR-181a-5p in myocardial ischemia model. MIAT can be a possible therapeutic target for controlling the progression of myocardial ischemia.

Detrimental Impact of Microbiota-Accessible Carbohydrate-Deprived Diet on Gut and Immune Homeostasis: An Overview.

Dietary fibers are non-digestible polysaccharides functionally known as microbiota-accessible carbohydrates (MACs), present in inadequate amounts in the Western diet. MACs are a main source of energy for gut bacteria so the abundance and variety of MACs can modulate gut microbial composition and function. This, in turn, impacts host immunity and health. In preclinical studies, MAC-deprived diet and disruption of gut homeostasis aggravate the development of inflammatory diseases, such as allergies, infections, and autoimmune diseases. The present review provides a synopsis on the impact of a low-MAC diet on gut homeostasis or, more specifically, on gut microbiota, gut epithelium, and immune cells.

FGF21 increases cholesterol efflux by upregulating ABCA1 through the ERK1/2-PPARγ-LXRα pathway in THP1 macrophage-derived foam cells.

FGF21, a member of the fibroblast growth factor superfamily, is an important endogenous regulator of systemic glucose and lipid metabolism. Elevated serum FGF21 levels have been reported in subjects with coronary heart disease and carotid artery plaques. However, whether FGF21 is associated with atherosclerotic diseases remains unclear. In this study, the effects of FGF21 on cholesterol efflux in THP1 macrophage-derived foam cells and the underlying mechanisms were investigated. THP1 macrophage-derived foam cells were incubated with 0, 25, 50, 100, 200, and 400 ng/mL of FGF21 for varying time periods (0, 6, 12, and 24 h). Cholesterol efflux onto apoA-1 was assessed by high-performance liquid chromatography assays, while change in ABCA1 expression was analyzed by western blot and real-time quantitative PCR. Incubation was performed with the ERK1/2-specific inhibitor PD98059, PPARγ-specific inhibitor GW9662, and LXRα siRNA. Our results show that FGF21 promotes cholesterol efflux and ABCA1 expression in THP1 macrophage-derived foam cells in a dose- and time-dependent manner. In addition, inhibition of ERK1/2 or PPARγ, or knockdown of LXRα attenuated FGF21-mediated promotion of ABCA1 expression and cholesterol efflux. These results demonstrate that FGF21 can promote cholesterol efflux by upregulating ABCA1 through the ERK1/2-PPARγ-LXRα pathway in THP1 macrophage-derived foam cells.