Circ-sh3rf3/GATA-4/miR-29a regulatory axis in fibroblast-myofibroblast differentiation and myocardial fibrosis.

The transdifferentiation from cardiac fibroblasts to myofibroblasts is an important event in the initiation of cardiac fibrosis. However, the underlying mechanism is not fully understood. Circ-sh3rf3 (circular RNA SH3 domain containing Ring Finger 3) is a novel circular RNA which was induced in hypertrophied ventricles by isoproterenol hydrochloride, and our work has established that it is a potential regulator in cardiac hypertrophy, but whether circ-sh3rf3 plays a role in cardiac fibrosis remains unclear, especially in the conversion of cardiac fibroblasts into myofibroblasts. Here, we found that circ-sh3rf3 was down-regulated in isoproterenol-treated rat cardiac fibroblasts and cardiomyocytes as well as during fibroblast differentiation into myofibroblasts. We further confirmed that circ-sh3rf3 could interact with GATA-4 proteins and reduce the expression of GATA-4, which in turn abolishes GATA-4 repression of miR-29a expression and thus up-regulates miR-29a expression, thereby inhibiting fibroblast-myofibroblast differentiation and myocardial fibrosis. Our work has established a novel Circ-sh3rf3/GATA-4/miR-29a regulatory cascade in fibroblast-myofibroblast differentiation and myocardial fibrosis, which provides a new therapeutic target for myocardial fibrosis.

ECMO combined with prone positioning strategies in COVID-19 respiratory distress syndrome.

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has already become a global pandemic as a public health emergency of international concern. Previous evidence from similar patient populations proved that carefully selected patients with severe ARDS who did not benefit from conventional treatment might be successfully supported with Veno-Venous extracorporeal membrane oxygenation (V-V ECMO). We now share the case reports of COVID-19 patients with ECMO combined prone position strategies.

EGF Protects Cells Against Dox-Induced Growth Arrest Through Activating Cyclin D1 Expression.

It has been reported that the antitumor drug doxorubicin (Dox) exerts its toxic effects via GATA-4 depletion and that over-expression of GATA-4 reverses Dox-induced toxicity and apoptosis; however, the precise mechanisms remain unclear. In this study, we observed, for the first time, that EGF protects cells against Dox-mediated growth arrest, G2/M-phase arrest, and apoptosis. Additionally, EGF expression was down-regulated in Dox-treated cells and up-regulated in GATA-4 over-expressing cells. Utilizing real-time PCR and western blotting analysis, we found that the expression of the cell cycle-associated protein cyclin D1 was inhibited in GATA-4-silenced cells and Dox-treated cells and was enhanced in GATA-4 over-expressing cells and EGF-treated cells. Furthermore, EGF treatment reversed the inhibited expression of cyclin D1 that was mediated by GATA-4 RNAi or Dox. Our results indicate that EGF, as a downstream target of Dox, may be involved in Dox-induced toxicity as well as in the protective role of GATA-4 against toxicity induced by Dox via regulating cyclin D1 expression, which elucidates a new molecular mechanism of Dox toxicity with important clinical implications.

EGF is required for cardiac differentiation of P19CL6 cells through interaction with GATA-4 in a time- and dose-dependent manner.

The regulation of cardiac differentiation is critical for maintaining normal cardiac development and function. The precise mechanisms whereby cardiac differentiation is regulated remain uncertain. Here, we have identified a GATA-4 target, EGF, which is essential for cardiogenesis and regulates cardiac differentiation in a dose- and time-dependent manner. Moreover, EGF demonstrates functional interaction with GATA-4 in inducing the cardiac differentiation of P19CL6 cells in a time- and dose-dependent manner. Biochemically, GATA-4 forms a complex with STAT3 to bind to the EGF promoter in response to EGF stimulation and cooperatively activate the EGF promoter. Functionally, the cooperation during EGF activation results in the subsequent activation of cyclin D1 expression, which partly accounts for the lack of additional induction of cardiac differentiation by the GATA-4/STAT3 complex. Thus, we propose a model in which the regulatory cascade of cardiac differentiation involves GATA-4, EGF, and cyclin D1.

Effects of mechanical ventilation with different tidal volume on oxidative stress and antioxidant in lung.

PURPOSE: The aim of this study was to investigate the changes in oxidative stress and antioxidants in lung tissue under different tidal volume ventilation conditions. METHODS: Forty-eight male Wistar rats were randomized into four groups, namely, group C, the control group, which was not ventilated, and groups C1, C2 and C3, the treatment groups, which were ventilated for 2 h with tidal volumes of 8, 30 and 42 ml/kg, respectively. The right middle lobe was assayed for malondialdehyde (MDA), the right posterior lobe was assayed using Western blotting for Nrf2, GCLm and SrX1 and the left lobe was assayed for Nrf2, GCLm and SrX1 mRNA. RESULTS: The MDA levels were increased in the three treatment groups, with MDA levels highest in group C3 and lowest in group C1 (C3 > C2 > C1) (all P < 0.05). The mRNA expression of Nrf2, GCLm and SrX1 was highest in group C3 and lowest in group 1 (C3 > C2 > C1) (all P < 0.05). No significant difference was observed between group C1 and group C (P > 0.05). A Western blot analysis showed that Nrf2, GCLm and SrX1 expression was highest in group C3 and lowest in group C1 (C3 > C2 > C1) (all P < 0.05). No significant difference was observed between group C1 and group C (P > 0.05). CONCLUSIONS: Oxidative stress and antioxidant enzyme levels in the lungs of rats were positively associated with the tidal volumes of mechanical ventilation, suggesting that higher tidal volumes cause more severe oxidative stress and increased antioxidant responses.

Total syntheses of parthenolide and its analogues with macrocyclic stereocontrol.

The first total synthesis of parthenolide (1) is described. The key feature of this synthesis is the formation of a 10-membered carbocylic ring by a macrocyclic stereocontrolled Barbier reaction, followed by a photoinduced Z/E isomerization. The biological evaluation of a small library of parthenolide analogues (19, 33, and 34) disclosed a preliminary structure-activity relationship (SAR). The results revealed that the C1, C10 double bond configuration of parthenolide has little or no effect on the activity, and the C6 and C7 configurations of the lactone ring have a moderate impact on the activities against some cancer cell lines.

Insulin induces proliferation and cardiac differentiation of P19CL6 cells in a dose-dependent manner.

Insulin is a peptide hormone produced by beta cells of the pancreas. The roles of insulin in energy metabolism have been well studied, with most of the attention focused on glucose utilization, but the roles of insulin in cell proliferation and differentiation remain unclear. In this study, we observed for the first time that 10 nmol/L insulin treatment induces cell proliferation and cardiac differentiation of P19CL6 cells, whereas 50 and 100 nmol/L insulin treatment induces P19CL6 cell apoptosis and blocks cardiac differentiation of P19CL6 cells. By using real-time polymerase chain reaction (PCR) and Western blotting analysis, we found that the mRNA levels of cyclin D1 and α myosin heavy chain (α-MHC) are induced upon 10 nmol/L insulin stimulation and inhibited upon 50/100 nmol/L insulin treatment, whereas the mRNA levels of BCL-2-antagonist of cell death (BAD) exists a reverse trend. The similar results were observed in P19CL6 cells expressing GATA-6 or peroxisome proliferator-activated receptor α (PPARα). Our results identified the downstream targets of insulin, cyclin D1, BAD, α-MHC, and GATA-4, elucidate a novel molecular mechanism of insulin in promoting cell proliferation and differentiation.

Insulin induces C2C12 cell proliferation and apoptosis through regulation of cyclin D1 and BAD expression.

Insulin is a secreted peptide hormone identified in human pancreas to promote glucose utilization. Insulin has been observed to induce cell proliferation and myogenesis in C2C12 cells. The precise mechanisms underlying the proliferation of C2C12 cells induced by insulin remain unclear. In this study, we observed for the first time that 10 nM insulin treatment promotes C2C12 cell proliferation. Additionally, 50 and 100 nM insulin treatment induces C2C12 cell apoptosis. By utilizing real-time PCR and Western blotting analysis, we found that the mRNA levels of cyclinD1 and BAD are induced upon 10 and 50 nM/100 nM insulin treatment, respectively. The similar results were observed in C2C12 cells expressing GATA-6 or PPARα. Our results identify for the first time the downstream targets of insulin, cyclin D1, and BAD, elucidate a new molecular mechanism of insulin in promoting cell proliferation and apoptosis.

SNPs of excision repair cross complementing group 5 and gastric cancer risk in Chinese populations.

We conducted a case-control study to determine the association between several potential SNPs of excision repair cross complementing group 5 (XPG) and gastric cancer susceptibility, and roles of XPG polymorphisms in combination with H.pylori infection in determining risk of gastric cancer. In our study, we collected 337 newly diagnosed gastric cancer cases and 347 health controls. Three SNPs of XPG, rs2296147T>C, rs2094258C>T and rs873601G>A, were genotyped using the Taqman real-time PCR method with a 7900 HT sequence detector system. H. pylori infection was diagnosed by ELISA. By multivariate logistic regression analysis, the rs2296147 CC genotype was associated with a decreased risk of gastric cancer (OR=0.52, 95% CI=0.27-0.97), and rs2094258 TT was associated with elevated risk (OR=2.13, 95% CI=1.22-3.35). Positive H.pylori individuals with rs2094258 TT genotypes demonstrated increased risk of gastric cancer (OR=2.13, 95% CI=1.22-3.35), while rs2296147 CC was associated with lower risk among patients with negative H.pylori (OR=0.45, 95%CI=0.22-0.89). Our findings suggested that XPG polymorphisms might contribute to risk of gastric cancer among Chinese populations, but the effect needs to be further validated by larger sample size studies.

Effects of Doxorubicin and Fenofibrate on the activities of NADH oxidase and citrate synthase in mice.

Doxorubicin (Dox) has widely been used as an anticancer drug, but its use is limited by serious toxicity to the heart, kidney and liver. Mitochondrial dysfunction is one of the potential mechanisms of toxicity but not fully understood. Fenofibrate, one of the peroxisome proliferator-activated receptor-alpha (PPARα) ligands, is involved in lipid metabolism which takes place primarily in the mitochondria, so mitochondrial function may be affected by fenofibrate. Therefore, we investigated the effects of DOX and fenofibrate on activities of both mitochondrial citrate synthase and NADH oxidase, which are marker enzymes in the tricarboxylic acid (TCA) cycle and a measure of the complex I-III-IV activity in electron transport chain, respectively. Dox (15 mg/kg) and/or fenofibrate (100 mg/kg/day) were administered to mice for 3 or 14 days, and the activities of citrate synthase and NADH oxidase were measured. Our study showed that Dox significantly inhibits the activity of citrate synthase while fenofibrate induces the activity. Similar to citrate synthase, NADH oxidase activity was also induced by fenofibrate except in spleen but inhibited by Dox except in the heart and liver. Furthermore, fenofibrate not only protects citrate synthase activity from Dox-induced toxicity in the ventricle but also significantly rescues NADH oxidase activity in the kidney. These results reveal the actions of fenofibrate and Dox on the mitochondria, and the underlying mechanism may be related to the toxicity of Dox, which has clinical implications in the side effects of Dox treatment by modulation of mitochondrial function.

A case-control study on the relationship between salt intake and salty taste and risk of gastric cancer.

AIM: To investigate the relationship between salt intake and salty taste and risk of gastric cancer. METHODS: A 1:2 matched hospital based case-control study including 300 patients with gastric cancer and 600 cancer-free subjects as controls. Subjects were interviewed with a structured questionnaire containing 80 items, which elicited information on dietary, lifestyle habits, smoking and drinking histories. Subjects were tested for salt taste sensitivity threshold (STST) using concentrated saline solutions (0.22-58.4 g/L). Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CI). RESULTS: Alcohol and tobacco consumption increased the risk of gastric cancer [OR (95% CI) was 2.27 (1.27-4.04) for alcohol and 2.41 (1.51-3.87) for tobacco]. A protective effect was observed in frequent consumption of fresh vegetable and fruit [OR (95% CI) was 0.92 (0.58-0.98) for fresh vegetable and 0.87 (0.67-0.93) for fruit]. Strong association was found between STST ≥ 5 and gastric cancer [OR = 5.71 (3.18-6.72)]. Increased STST score was significantly associated with salted food intake and salty taste preference (P < 0.05). CONCLUSION: A high STST score is strongly associated with gastric cancer risk. STST can be used to evaluate an inherited characteristic of salt preference, and it is a simple index to verify the salt intake in clinic.

[Different doses transplanted microglia effect on ß-amyloid protein in rat Alzheimer's models].

OBJECTIVE: To explore the effects of different doses of transplanted microglia (MG) on ß-amyloid protein (Aß) in rat brain model of Alzheimer's disease (AD). METHODS: A total of 60 SD rats were randomly divided into experimental group and control group. The experimental group was injected with Aß-42 and the control group saline in hippocampus. At Day 3, different doses of continuously expressed enhanced green fluorescent protein (EGFP) microglial cells cultured in vitro were injected into the rats via carotid artery. At Day 3 post-injection, Aß was labeled by immunofluorescent method. And the expressions of EGFP microglia and Aß were detected in hippocampus by fluorescence. The relative brain expression of ß-amyloid precursor protein (APP) mRNA was analyzed by RT-PCR (reverse transcription-polymerase chain reaction). RESULTS: The mean fluorescent intensity of EGFP was significantly higher in each experimental group (5.62 ± 0.61, 8.85 ± 0.33, 10.24 ± 0.45, 11.26 ± 0.37, 12.75 ± 0.65) than the control group (2.22 ± 0.32, all P < 0.05); Fluorescent immunohistochemistry showed that the mean fluorescent intensity of Aß in the 4×10(6) dose group (9.53 ± 0.23) and the 12×10(6) dose group (8.32 ± 0.46) were significantly higher than that in the 8×10(6) dose group (4.56 ± 0.13, both P < 0.05); The fluorescent regions had partial consistence of EGFP and Aß; RT-PCR (reverse transcription-polymerase chain reaction) results showed that the relative expressions of APP mRNA in the 4×10(6) dose group (1.83 ± 0.22) and the 12×10(6) dose group (1.94 ± 0.28) were significantly higher than that in the 8×10(6) dose group (0.43 ± 0.12, both P < 0.05). CONCLUSION: Aß has the chemotactic role of MG. MG may swallow Aß protein partially. But a high dose of MG also accelerates the formation of Aß.