Stabilization of ß-Catenin Directs HEB to Limit Thymic Selection.

Activation of ß-catenin in CD4+CD8+ double-positive (DP) thymocytes halts development before the thymic selection stage and predisposes to transformation. Leukemogenesis, but not the developmental block, depends on TCF-1, ß-catenin's DNA-binding partner. In this study, we show that ß-catenin activation directs the DNA-binding protein HEB to block DP thymocyte development. Conditional loss of HEB in DP thymocytes with stabilized ß-catenin restores the frequencies of postselection TCRßhi/CCR7+ and TCRßhi/CD69+ DPs and their cell-cycle profile. This recovery is associated with significant reversal of ß-catenin-induced expression changes, particularly those related to the CD69+ DP cell signature and to cell-cycle pathways. Stabilizing ß-catenin in DP thymocytes directs HEB binding to ≈11,000 novel DNA sites throughout the genome. Novel HEB sites mark most CD69+ DP cell signature genes that change expression upon activation of ß-catenin and then revert after loss of HEB. Moreover, many of the novel HEB sites occupy promoter regions of genes enriched in mitotic cell cycle pathways. HEB binding to those regions correlates with downregulation of the associated genes, and HEB inactivation restores expression to physiologic levels. These findings highlight a molecular interplay between HEB and ß-catenin that can impair thymic development.

Fragility of cardiovascular outcome trials (CVOTs) examining nutrition interventions among patients with diabetes mellitus: a systematic review of randomized controlled trials.

PURPOSE: There is controversy regarding the optimal statistical method to interpret how robust is a statistically significant result. The fragility index (FI) and the reverse fragility index (RFI) are quantitative measures that can facilitate the appraisal of a clinical trial's robustness. This study was performed to evaluate the FI and RFI of randomized controlled trials (RCTs) examining nutritional interventions in patients with diabetes mellitus, focusing on cardiovascular outcomes. METHODS: A systematic search was conducted and relevant RCTs were identified in three databases. RCTs examining nutritional interventions (supplements or dietary patterns) in patients with DM with dichotomous primary endpoints involving cardiovascular outcomes were eligible. Data were extracted to compose 2 × 2 event tables and the FI and RFI were calculated for each comparison, using Fisher's exact test. Risk of bias (RoB) of the included RCTs was assessed with the Cochrane RoB 2.0 tool. RESULTS: A total of 14,315 records were screened and 10 RCTs were included in the analyses. The median FI of the paired comparisons was 3 (IQR: 2-4) and the median RFI was 8 (IQR: 4.5-17). RoB and heterogeneity were low. CONCLUSIONS: RCTs examining nutritional interventions and cardiovascular outcomes among patients with diabetes mellitus appear to be statistically fragile. Τhe FI and the RFI can be reported and interpreted as an additional perspective of a trial's robustness. HIGHLIGHTS: • In the evidence-healthcare era, assessing how robust statistically significant results are remains a matter of controversy. • Recently, the fragility index (FI) and reverse fragility index (RFI) were proposed to assess the robustness of randomized controlled trials (RCTs) with 2 × 2 comparisons. • When applying the FI and RFI, RCTs examining nutritional interventions and cardiovascular outcomes among patients with diabetes mellitus (DM) appear to be statistically fragile. • Τhe FI and the RFI can be reported and interpreted as an additional perspective of a trial's robustness. • RCTs implementing nutrition interventions among patients with DM can improve their methodology.

Ketogenic therapy for Parkinson's disease: A systematic review and synthesis without meta-analysis of animal and human trials.

OBJECTIVE: The aim of the present systematic review was to assess the efficacy of ketogenic therapy in Parkinson's disease (PD), using all available data from randomized controlled trials (RCTs) on humans and animal studies with PD models. DESIGN: Systematic review of in vivo studies. METHODS: Studies related to the research question were identified through searches in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, clinicaltrials.gov and the gray literature, from inception until November 2021. Rayyan was employed to screen and identify all studies fulfilling the inclusion criteria. Cochrane's revised Risk of Bias 2.0 and SYRCLE tools evaluated bias in RCTs and animal studies, respectively. An effect direction plot was developed to synthesize the evidence of the RCTs. RESULTS: Twelve studies were identified and included in the qualitative synthesis (4 RCTs and 8 animal trials). Interventions included ketogenic diets (KDs), supplementation with medium-chain triglyceride (MCT) oil, caprylic acid administration and ketone ester drinks. The animal research used zebrafish and rodents, and PD was toxin-induced. Based on the available RCTs, ketogenic therapy does not improve motor coordination and functioning, cognitive impairment, anthropometrics, blood lipids and glycemic control, exercise performance or voice disorders in patients with PD. The evidence is scattered and heterogenous, with single trials assessing different outcomes; thus, a synthesis of the evidence cannot be conclusive regarding the efficacy of ketogenic therapy. On the other hand, animal studies tend to demonstrate more promising results, with marked improvements in locomotor activity, dopaminergic activity, redox status, and inflammatory markers. CONCLUSIONS: Although animal studies indicate promising results, research on the effect of ketogenic therapy in PD is still in its infancy, with RCTs conducted on humans being heterogeneous and lacking PD-specific outcomes. More studies are required to recommend or refute the use of ketogenic therapy in PD.

Comparative efficacy of glucose-lowering medications on body weight and blood pressure in patients with type 2 diabetes: A systematic review and network meta-analysis.

AIM: To compare the effects of glucose-lowering drugs on body weight and blood pressure in adults with type 2 diabetes. METHODS: We searched Medline, Embase, the Cochrane Library, and grey literature sources until 29 September 2020 for randomized controlled trials of at least 24 weeks' duration assessing the effects of glucose-lowering drugs on body weight and blood pressure in adults with type 2 diabetes. We performed frequentist network meta-analyses and calculated weighted mean differences and 95% confidence intervals combining trial arms of different approved doses of a given intervention into a single group. We evaluated the confidence in pooled estimates using the CINeMA (Confidence In Network Meta-Analysis) framework. RESULTS: In total, 424 trials (276 336 patients) assessing 21 antidiabetic medications from nine drug classes were included. Subcutaneous semaglutide was the most efficacious in reducing body weight followed by oral semaglutide, exenatide twice-daily, liraglutide, and the sodium-glucose co-transporter-2 (SGLT-2) inhibitors empagliflozin, canagliflozin, dapagliflozin and ertugliflozin. The same agents also conferred the greatest reductions in systolic blood pressure. Metformin had a modest effect in reducing body weight and systolic blood pressure. Diastolic blood pressure was reduced with the SGLT-2 inhibitors pioglitazone, exenatide twice-daily and semaglutide. In subgroup analyses of trials with over 52 weeks' duration, semaglutide and SGLT-2 inhibitors reduced both body weight and systolic blood pressure. CONCLUSIONS: Semaglutide and SGLT-2 inhibitors conferred reductions both in body weight and blood pressure that were sustainable for over 1 year of treatment. These agents may be preferable treatment options for patients with type 2 diabetes who are overweight/obese and/or hypertensive.