Insufficient TRPM5 Mediates Lipotoxicity-induced Pancreatic ß-cell Dysfunction.

OBJECTIVE: While the reduction of transient receptor potential channel subfamily M member 5 (TRPM5) has been reported in islet cells from type 2 diabetic (T2D) mouse models, its role in lipotoxicity-induced pancreatic ß-cell dysfunction remains unclear. This study aims to study its role. METHODS: Pancreas slices were prepared from mice subjected to a high-fat-diet (HFD) at different time points, and TRPM5 expression in the pancreatic ß cells was examined using immunofluorescence staining. Glucose-stimulated insulin secretion (GSIS) defects caused by lipotoxicity were mimicked by saturated fatty acid palmitate (Palm). Primary mouse islets and mouse insulinoma MIN6 cells were treated with Palm, and the TRPM5 expression was detected using qRT-PCR and Western blotting. Palm-induced GSIS defects were measured following siRNA-based Trpm5 knockdown. The detrimental effects of Palm on primary mouse islets were also assessed after overexpressing Trpm5 via an adenovirus-derived Trpm5 (Ad-Trpm5). RESULTS: HFD feeding decreased the mRNA levels and protein expression of TRPM5 in mouse pancreatic islets. Palm reduced TRPM5 protein expression in a time- and dose-dependent manner in MIN6 cells. Palm also inhibited TRPM5 expression in primary mouse islets. Knockdown of Trpm5 inhibited insulin secretion upon high glucose stimulation but had little effect on insulin biosynthesis. Overexpression of Trpm5 reversed Palm-induced GSIS defects and the production of functional maturation molecules unique to ß cells. CONCLUSION: Our findings suggest that lipotoxicity inhibits TRPM5 expression in pancreatic ß cells both in vivo and in vitro and, in turn, drives ß-cell dysfunction.

Protocol for in vivo and ex vivo assessments of glucose-stimulated insulin secretion in mouse islet ß cells.

Pancreatic islet ß cells secrete insulin in a biphasic manner when sensing high blood glucose level. This protocol describes the evaluation of different phases of insulin secretion, as well as basal, glucose-stimulated and total insulin secretion abilities, thereby enabling precise assessment of ß cell function both in vivo and ex vivo. The in vivo assay consists of intravenous tube imbedding surgery and hyperglycemic clamp. The ex vivo assay consists of islet isolation, dynamic perfusion and static immersion. For complete details on the use and execution of this protocol, please refer to Sun et al. (2021).

Low Calf Circumference Predicts Nutritional Risks in Hospitalized Patients Aged More Than 80 Years.

OBJECTIVE: The aim of this study was to determine whether low calf circumference (CC) could predict nutritional risk and the cutoff values of CC for predicting nutritional risk in hospitalized patients aged ⪖ 80 years. METHODS: A total of 1,234 consecutive patients aged ⪖ 80 years were enrolled in this study. On admission, demographic data, CC, and laboratory parameters were obtained. Patients with Nutritional Risk Screening 2002 (NRS-2002) total score ⪖ 3 were considered as having nutritional risk. RESULTS: CC values were significantly lower in patients with nutritional risk compared to those in patients without nutritional risk [27.00 (24.50-31.00) vs. 31.00 (29.00-33.50], P < 0.001]. CC was negatively correlated with age and nutritional risk scores. Logistic regression analysis of nutritional risk revealed that body mass index, albumin level, hemoglobin level, cerebral infarction, neoplasms, and CC (OR, 0.897; 95% confidence interval, 0.856-0.941; P < 0.001) were independent impact factors of nutritional risk. Nutritional risk scores increased with a decrease in CC. In men, the best CC cutoff value for predicting nutritional risk according to the NRS-2002 was 29.75 cm. In women, the cutoff value was 28.25 cm. CONCLUSION: CC is a simple, noninvasive, and valid anthropometric measure to predict nutritional risk for hospitalized patients aged ⪖ 80 years.

Ets1-Mediated Acetylation of FoxO1 Is Critical for Gluconeogenesis Regulation during Feed-Fast Cycles.

The homeostatic balance of hepatic glucose uptake and production is exquisitely controlled by hormonal signals during feed-fast cycles. FoxO1, a transcription factor that functions in the regulation of glucose homeostasis, undergoes posttranslational modifications, such as acetylation, in response to hormonal signals, yet the mechanism remains poorly elucidated. Through expression profiling of 324 co-factors of CBP, a well-known acetyl-transferase of FoxO1, we identify Ets1 as a modulator of FoxO1 acetylation that is highly associated with feed-fast cycles. Mechanistic assays suggest that Ets1 enhances FoxO1 acetylation through the formation of a complex with CBP, which further promotes FoxO1 nuclear exclusion and inhibits its binding to gluconeogenic promoters. Functional studies further reveal that Ets1 inhibits gluconeogenesis under physiological and diabetes statuses, while the hyperinsulinemic-euglycemic clamp assay suggests hepatocyte Ets1 knockout mice have enhanced hepatic glucose production. Our study identifies Ets1 as an enhancer of FoxO1 acetylation and a repressor of hepatic gluconeogenesis in response to hormonal signals.

[Influence of TLR2- and TLR4-activated Mesenchymal Stem Cells on Migration of Cord Blood CD34+ Cells].

OBJECTIVE: This study was aimed to investigate the possible effect of Toll-like receptors 2 (TLR2) and Toll-like receptors 4 (TLR4) on the migration function of umbilical cord blood (UCB) CD34+ hematopoietic stem/progenitor cells induced by bone marrow-derived mesenchymal stem cells (MSCs) and to explore the underlying mechanism. METHODS: The expression of TLR2 and TLR4 on MSC was detected with flow cytometry. After the MSC were pretreated with TLR2 agonist (PAM3CSK4) and/or TLR4 agonist (LPS), the supernatants were collected. The effect of the supernatants on the migration of CD34+ cells was evaluated with chemotaxis assays. Alterations of chemokine (SDF-1) secreted by MSC in the supernatants were assayed by ELISA. RESULTS: The expression levels of TLR2 and TLR4 were (31.5±4.6)% and (85.6±6.7)% respectively. Compared with the blank group, the migration ability of CD34+ cells increased significantly in control, LPS and/or PAM3CSK4 groups (P<0.01). Further study found that LPS and/or PAM3CSK4 enhanced the chemotactic ability of CD34+ cells (P<0.05), but the concentration of SDF-1 was not changed significantly in all of LPS and/or PAM3CSK4 groups (P>0.05) in comparison with the control group. CONCLUSION: TLR2 and TLR4 signalings may indirectly increase the migration of CD34+ hematopoietic stem/progenitor cells by modulating BM-MSC functions, which may not significantly correlate with the production of chemokine SDF-1 by MSCs.

[The clinical value of F-18 FDG PET/CT in patients with secondary hemophagocytic syndrome].

The aim of this study was to investigate the role of F-18 fluoro-2-deoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in diagnosis and prognostic evaluation of secondary hemophagocytic syndrome (HPS). A total of 11 secondary HPS patients examined with 18F-FDG-PET/CT were retrospectively analyzed. The diagnostic value of F-18 FDG PET/CT for malignancy detection was assessed. The values of maximum standardized uptake value (SUV(max)) in spleen (SUVS(p)) and in bone marrow (SUVBM) were measured to analyze their relationship with various laboratorial parameters and clinical outcome of secondary HPS patients. The results showed that 4 out of the 11 patients had malignancies, the sensitivity, specificity and diagnostic accuracy of F-18 FDG PET/CT for malignancy detection were 100%, 66.7% and 75% respectively, the SUV(max) of spleen and bone marrow showed no significant correlation with laboratorial parameters, a maximum SUVS(p) of 3.10 and a maximum SUVBM of 3.47 were the optimal cutoffs for predicting patients' outcome, the increased uptake of F-18 FDG in the BM and spleen were significantly associated with shorter survival time according to univariate analysis. It is concluded that 18F-FDG PET/CT may especially play an important role in diagnosis and predicting outcome of secondary HPS for the small sample size.

[Influence of TLR2 and TLR4 agonists on migration of human bone marrow mesenchymal stem cells].

This study was aimed to investigate the influence of TLR2 and TLR4 agonists on the migration and adhesion activity of human bone marrow-derived mesenchymal stem cells (MSC) and to clarify the underlying mechanisms. The expression of TLR2 and TLR4 on MSC was detected by flow cytometry. The effects of TLR2 agonist (PAM3CSK4) and TLR2 agonist (LPS) on MSC migration and adhesion ability were evaluated with chemotaxis and adhesion test. The results indicated that expressive levels of TLR2 and TLR4 on surface of human bone marrow MSC were (24.5 ± 3.2)% and (91.3 ± 5.2)% respectively. Compared with the control group, the migration activity of MSC toward SDF-1 was decreased significantly in PAM3CSK4 group, while the adhesion activity of MSC was promoted by PAM3CSK4 exposure. However, both the migration activity toward SDF-1 and the adhesion activity of MSC were not changed significantly in LPS-treated group. Further, it was found that PAM3CSK4 did not affect the expressive level of CXCR4 on MSC, however, it could inhibit the spontaneous migration of MSC in dose dependent manner. It is concluded that activation of TLR2 can decrease the migration ability of MSC, which may associate with the decreased spontaneous migration ability and the increased adhesion activity of MSC.

[Inhibitory effect of silencing of HMGB1 gene expression on the invasive and metastatic abilities of MGC-803 gastric cancer cells].

OBJECTIVE: To investigate the effect of high mobility group box-1 (high mobility group box B 1, HMGB1) on the invasive and metastatic abilities of gastric cancer cell line MGC-803 and analyze the possible mechanisms. METHODS: HMGB1 gene targeting siRNA was designed and synthesized, and HMGB1 siRNA oligonucleotides were transfected into the MGC-803 cells with Lipofectamine 2000. The invasive and migratory abilities were detected by transwell assay and scratch assay. The Matrigel matrix glue adhesive ability of MGC-803 cells was evaluated by MTT assay. NF-κB activity was detected by electrophoretic mobility shift assay. The mRNA and protein levels of HMGB1 and MMP-9 were determined by RT-PCR and Western blot, respectively. RESULTS: The siRNA down-regulated the levels of HMGB1 mRNA and protein. Compared with that of the control group, the number of invasive (142.7 ± 3.4 /view vs. 303.5 ± 4.3/view) and migratory (293.7 ± 4.4/view vs. 445.5 ± 5.6/view) cells was significantly increased (P < 0.05) and the adhesive ability of MGC-803 cells to Matrigel was significantly elevated (33.4 ± 0.03% vs. 57.4 ± 4.2%, P < 0.05). In addition, silencing of HMGB1 gene significantly inhibited the activity of NF-κB and the relative expression folds of mRNA (0.2 ± 0.1 vs. 1.4 ± 0.4, P < 0.05)and protein (0.4 ± 0.1 vs. 2.3 ± 0.7, P < 0.05) of MMP-9. CONCLUSION: Silencing of HMGB1 can effectively inhibit the invasion and migration of gastric cancer cells and this effect of HMGB1 may be partly due to its regulation of NF-κB and MMP-9 expressions.

Non-alcoholic fatty liver disease's prevalence and impact on alanine aminotransferase associated with metabolic syndrome in the Chinese.

BACKGROUND AND AIM: Non-alcoholic fatty liver disease (NAFLD) is becoming a major public health hazard in China. The present study aimed to estimate the prevalence of NAFLD, NAFLD with abnormal serum alanine aminotransferase (ALT) levels, and determine the potential associations of ALT levels with the components of metabolic syndrome (MetS) in the absence or presence of NAFLD in Chinese adults. METHODS: A population-based cross-sectional survey was conducted with 2226 participants. Physical examinations, laboratory tests and hepatic ultrasounds were performed. Individuals were further stratified into higher or lower ALT subgroups with the upper quartiles of ALT in this population. The MetS was identified according to the criteria of the Chinese Joint Committee for Developing Chinese Guidelines (JCDCG). RESULTS: The standardized prevalence of NAFLD was 23.3% (NAFLD with abnormal ALT levels, 3.1%), 26.5% (NAFLD with abnormal ALT levels, 5.1%) in males, and 19.7% (NAFLD with abnormal ALT levels, 0.9%) in females. Multivariate logistic analysis revealed that higher ALT was significantly associated with elevated triglyceride (TG) in the non-NAFLD participants, independent of age, smoking status, drinking status, and other MetS-related measures with odds ratios (95% confidence intervals) of 3.4 (1.6-7.1) and 2.3 (1.4-3.7) in males and females, respectively. On the other hand, the higher ALT was statistically associated with elevated TG and hyperglycemia in the NAFLD cases with odds ratios of 2.2 to 2.5 (P<0.05). CONCLUSIONS: The prevalence of NAFLD has become epidemic in Shanghai adults. NAFLD combined with ALT levels may be used to identify the individuals at the different risk levels of metabolic disorders.