Effects of active farnesoid X receptor on GLUTag enteroendocrine L cells
MOLECULAR AND CELLULAR ENDOCRINOLOGY
Authors: Niss, Kristoffer; Jakobsson, Magnus E.; Westergaard, David; Belling, Kirstine G.; Olsen, Jesper, V; Brunak, Soren
Abstract
Activated transcription factor (TF) farnesoid X receptor (FXR) represses glucagon-like peptide-1 (GLP-1) secretion in enteroendocrine L cells. This, in turn, reduces insulin secretion, which is triggered when beta cells bind GLP-1. Preventing FXR activation could boost GLP-1 production and insulin secretion. Yet, FXR's broader role in L cell biology still lacks understanding. Here, we show that FXR is a multifaceted TF in L cells using proteomics and gene expression data generated on GLUTag L cells. Most striking, 252 proteins regulated upon glucose stimulation have their abundances neutralized upon FXR activation. Mitochondrial repression or glucose import block are likely mechanisms of this. Further, FXR physically targets bile acid metabolism proteins, growth factors and other TFs, regulates ChREBP, while extensive text-mining found 30 FXR-regulated proteins to be well-known in L cell biology. Taken together, this outlines FXR as a powerful TF, where GLP-1 secretion block is just one of many
Real-world evidence of the effectiveness on glycaemic control of early simultaneous versus later sequential initiation of basal insulin and glucagon-like peptide-1 receptor agonists
DIABETES OBESITY & METABOLISM
Authors: Rosenstock, Julio; Ampudia-Blasco, Francisco Javier; Lubwama, Robert; Peng, Xuejun Victor; Boss, Anders; Shi, Lizheng; Fonseca, Vivian
Abstract
Aim To assess the impact of the timing of initiating both basal insulin and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) on reaching glycaemic control targets over 6 and 12 months in people with type 2 diabetes (T2D) uncontrolled on oral antihyperglycaemic drugs with an HbA1c of 9% or higher. Methods This retrospective cohort study assessed the impact of the timing of initiating both basal insulin and GLP-1 RA therapies on reaching glycaemic targets (HbA1c < 7% and <8%, and >= 1% and >= 2% HbA1c reduction) over 12 months in people with markedly uncontrolled T2D (HbA1c >= 9%) on oral antihyperglycaemic drugs identified on the Optum Humedica database (electronic medical records; 1 January 2011 to 30 June 2017). Study cohorts were defined by the days between initiating each injectable: cohort A, 30 days or less (simultaneous initiation) and cohorts B, 31-90, C, 91-180, D, 181-270 and E, 271-360 days (sequential initiation). Results Cohort A had the best glycaemic outcomes at 6 and 12 months for all four endpoints, followed by cohort B. The likelihood of achieving an HbA1c of less than 7% did not significantly differ between cohorts A and B (hazard ratio [95% confidence interval]: 0.87 [0.76-1.01]); cohorts C, D and E were significantly less likely to achieve an HbA1c of less than 7% than cohort A (0.62 [0.53-0.72]; 0.62 [0.53-0.72]; 0.63 [0.54-0.73]). Conclusions In people with uncontrolled T2D requiring treatment with a GLP-1 RA and basal insulin, greater improvements in glycaemic control were observed when both therapies were initiated within close proximity of one another (<= 90 days) compared with initiation 91-360 days apart.