Hepatocyte differentiation of human induced pluripotent stem cells is modulated by stearoyl-CoA desaturase 1 activity.

Stearoyl-CoA desaturase 1 (SCD1) plays important roles in organ development, glucose tolerance, insulin sensitivity, and cancer. Here, we examined the role of SCD1 for the differentiation of human induced pluripotent stem (hiPS) cells to liver cells by using drug inhibition and biochemical experiments. hiPS cells cultured in a pro-hepatic medium were exposed to an SCD1 inhibitor at various stages throughout differentiation. Liver-specific markers, specifically α-fetoprotein, albumin and urea in conditioned medium, and hepatocyte nuclear factor 4α (HNF4α) and cytochrome P450 7A1 (CYP7A1) gene expressions and triglyceride in cellular extracts were analyzed at various development stages. Measures of hepatocyte-specific function and triglyceride accumulation in later stages were strongly inhibited a minimum of -29% (P < 0.05) by SCD1 inhibitor in the early stage of hepatic differentiation and effectively reversed (>30%, P < 0.01) by the addition of oleate. The results were also reproducible with human primary mononuclear cells (hPMN). SCD1 inhibitor had no significant effect on liver-specific markers when it was added in the hepatic maturation stage. However, it strikingly led to higher albumin (1.6-fold, P = 0.03) and urea (1.9-fold, P = 0.02) production, and HNF4α (1.9-fold, P = 0.02) and CYP7A1 (1.3-fold, P = 0.03) expression upon incubation during the lineage-commitment stage. Hepatic differentiation from cultured hiPS cells is sensitive to SCD1 inhibition and this sensitivity is affected by the stage of cellular differentiation. Notably, findings also indicate that this notion can be extended to hPMN. The requirement for SCD1 activity in functional differentiation of hepatocytes may have relevance for human liver disease and metabolic dysregulation.

Investigation of the Molecular Mechanism of Coagulopathy in Severe and Critical Patients With COVID-19.

Coagulopathy is a frequently reported finding in the pathology of coronavirus disease 2019 (COVID-19); however, the molecular mechanism, the involved coagulation factors, and the role of regulatory proteins in homeostasis are not fully investigated. We explored the dynamic changes of nine coagulation tests in patients and controls to propose a molecular mechanism for COVID-19-associated coagulopathy. Coagulation tests including prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen (FIB), lupus anticoagulant (LAC), proteins C and S, antithrombin III (ATIII), D-dimer, and fibrin degradation products (FDPs) were performed on plasma collected from 105 individuals (35 critical patients, 35 severe patients, and 35 healthy controls). There was a statically significant difference when the results of the critical (CRT) and/or severe (SVR) group for the following tests were compared to the control (CRL) group: PTCRT (15.014) and PTSVR (13.846) (PTCRL = 13.383, p < 0.001), PTTCRT (42.923) and PTTSVR (37.8) (PTTCRL = 36.494, p < 0.001), LACCRT (49.414) and LACSVR (47.046) (LACCRL = 40.763, p < 0.001), FIBCRT (537.66) and FIBSVR (480.29) (FIBCRL = 283.57, p < 0.001), ProCCRT (85.57%) and ProCSVR (99.34%) (ProCCRL = 94.31%, p = 0.04), ProSCRT (62.91%) and ProSSVR (65.06%) (ProSCRL = 75.03%, p < 0.001), D-dimer (p < 0.0001, χ2 = 34.812), and FDP (p < 0.002, χ2 = 15.205). No significant association was found in the ATIII results in groups (ATIIICRT = 95.71% and ATIIISVR = 99.63%; ATIIICRL = 98.74%, p = 0.321). D-dimer, FIB, PT, PTT, LAC, protein S, FDP, and protein C (ordered according to p-values) have significance in the prognosis of patients. Disruptions in homeostasis in protein C (and S), VIII/VIIIa and V/Va axes, probably play a role in COVID-19-associated coagulopathy.

Quercetin attenuated oxidative DNA damage through NRF2 signaling pathway in rats with DMH induced colon carcinogenesis.

Accumulating recent studies have demonstrated the preventive and therapeutic effects of polyphonic compounds such as quercetin in colorectal cancer. Therefore, we aimed to evaluate the underlying mechanisms for positive effects of quercetin in rats with 1,2-dimethylhydrazine (DMH)- induced colorectal cancer. For this purpose, male Wistar rats were classified as 6 groups, including group 1 without any intervention, group 2 as quercetin received rats (50 mg/kg), groups 3 as DMH received rats (20 mg/kg) group 4-6 DMH and quercetin received rats. DNA damage, DNA repair, the expression levels and activities of enzymic antioxidants, non-enzymic antioxidants, and NRF2/Keap1 signaling were evaluated in colon tissues of all groups. Our results showed significant suppression of DNA damage and induction of DNA repair in DMH + Quercetin groups, particularly in entire-period in comparison to other groups (p < .05). The expression levels and activities of enzymic and non-enzymic antioxidants were increased in DMH + Quercetin groups (p < .05). Lipid and protein peroxidation were significantly suppressed in DMH + Quercetin groups (p < .05). In addition, quercetin also modulated NRF2/Keap1 signaling and its targets, detoxifying enzymes in DMH + Quercetin groups. Our finding demonstrated that quercetin supplementation effectively reversed DMH-mediated oxidative stress and DNA damage through targeting NRF2/Keap1 signaling pathway.