Upregulation of rate-limiting enzymes in cholesterol metabolism by PKCδ mediates endothelial apoptosis in diabetic wound healing.

Diabetic foot ulcer (DFU) is a prevalent complication of diabetes that poses significant challenges in terms of treatment and management. It is characterized by heightened endothelial apoptosis and impaired angiogenesis. In this study, we aimed to investigate the role of protein kinase Cδ (PKCδ) in regulating endothelial apoptosis in diabetic wounds by promoting cholesterol biosynthesis. The expression of PKCδ was increased in human umbilical vascular endothelial cells (HUVECs) cultivated in high glucose medium and skin tissue isolated from diabetic mice. High glucose-induced HUVECs apoptosis was reduced by PKCδ inhibition with siRNA or rottlerin. RNA-seq identified two enzymes, 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), as the downstream of PKCδ. PKCδ knockdown or inhibition suppressed the expression of HMGCS1 and HMGCR and lowered free cholesterol (FC) levels. Cholesterol restored high glucose-induced apoptosis in siRNA- or rottlerin-treated HUVECs. In vivo use of rosuvastatin calcium, an inhibitor of HMGCR, downregulated free cholesterol levels and accelerated the wound healing process. In conclusion, PKCδ expression in endothelial cells was activated by high glucose, which subsequently upregulates the expression of two enzymes catalyzing cholesterol biosynthesis, HMGCS1 and HMGCR. Enhanced cholesterol biosynthesis raises free cholesterol levels, promotes endothelial apoptosis, and finally delays wound healing.

Thalidomide for Patients with ß-Thalassemia: A Multicenter Experience.

OBJECTIVE: This study focused on the efficacy and safety of thalidomide for patients with ß-thalassemia in a multicenter trial. METHODS: Patients with non-transfusion-dependent thalassemia (NTDT) or transfusion-dependent thalassemia (TDT), who were unable to pursue conventional therapy with transfusion and chelation, were recruited over 3 years in three centers in southern China. We evaluated the efficacy and safety of thalidomide in the short-term (three months) and long-term follow-up (12 and 24 months). Response to thalidomide was defined as follows: Main Responder (MaR) showing an increase in hemoglobin (Hb) level of >2.0 g/dl or free from blood transfusion and Minor Responder (MiR) achieving elevated Hb level of 1.0-2.0 g/dl or ≥50% reduction in blood transfusion frequency. RESULTS: The overall response rate (ORR) was 93.5%, with MaR and MiR rates accounting for 62.9% and 30.6% in short-term follow-up. For patients with NTDT, the Hb level increased from a baseline mean of 6.8±1.1 g/dl to 9.7±1.9 g/dl (P<0.001). Elevated Hb was mainly attributable to increased fetal hemoglobin (HbF) levels. Among patients with TDT, while an increase in the average Hb concentration was observed, there was a significant drop in yearly transfusions from 20.7±7.7 to 5.8±6.8 blood units per year (P<0.001). The response of patients in both categories was sustained even after an average follow up of 14.6±9.6 months (3-37 months). Minimal side-effects were documented throughout, except peripheral neurotoxicity in one patient. Logistic regression analysis identified the ratio of HbF at baseline (P=0.038, OR=1.111, 95% CI: 1.006-1.226) as an independent risk factor for the primary response to thalidomide. CONCLUSION: Thalidomide had significant therapeutic effects on patients with ß-thalassemia with a sustained response. Peripheral neuropathy is one of the most feared complications. While these preliminary results support the potential long-term efficacy of thalidomide as a therapeutic agent for ß-thalassemia, several issues need to be addressed before its application in the clinic.

Roles of Cyclooxygenase-2 gene -765G > C (rs20417) and -1195G > A (rs689466) polymorphisms in gastric cancer: A systematic review and meta-analysis.

BACKGROUND: The roles of cyclooxygenase-2 (COX2) -765G > C (rs20417) and -1195G > A (rs689466) polymorphisms in gastric cancer were intensively analyzed, but the results of these studies were inconsistent. We conducted a meta-analysis and trial sequential analysis to elucidate the associations between these two COX2 polymorphisms and gastric cancer risk. METHODS: Eligible studies were searched in PubMed, Embase, Cochrane library databases, China National Knowledge Infrastructure, Vip, and Wanfang databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the genetic correlation between COX2 polymorphisms and gastric cancer susceptibility in five genetic models. Trial sequential analysis (TSA) was conducted to estimate whether the evidence of the results is sufficient. Furthermore, their interactions with Helicobacter pylori (H. pylori) or smoking in gastric cancer were also assessed using a case-only method. RESULTS: The COX2 gene -765G > C polymorphism showed no significant association with gastric cancer susceptibility under all the five genetic models (take the allelic model for example: OR = 1.41, 95% CI: 0.95-2.09) in total analysis, and the stratification analysis by ethnicity indicated a similar association in Caucasian group under four genetic models (allelic model, dominant model, homozygous model, and heterozygous model). But in the subgroup of the Asian population, the -765G > C polymorphism was significantly associated with gastric cancer risk under the same contrast. The COX2 -1195G > A polymorphism showed significant correlation with gastric cancer susceptibility in total analysis, and stratification analysis by ethnicity also revealed a similar association in both Asian and Caucasian groups under the same contrast. Moreover, TSA confirmed such associations. Both H. pylori infection and cigarette smoking interacted with -765 C allele in gastric cancer (OR = 3.79, 95% CI: 1.15-12.43 and OR = 2.48, 95% CI: 1.38-4.48, respectively), but not in -1195 A allele (OR = 1.96, 95% CI: 0.62-6.21, and OR = 1.24, 95% CI: 0.93-1.64, respectively). CONCLUSIONS: COX2 -765G > C polymorphism may serve as a genetic biomarker of gastric cancer in Asians, but not in Caucasians. COX2 -1195G > A polymorphism may serve as a genetic biomarker of gastric cancer in both Asians and Caucasians. The -765G > C, rather than -1195G > A polymorphism interacted with H. pylori infection or cigarette smoking to increase gastric cancer risk.