Objectives: It is controversial whether sodium glucose transporter (SGLT) 2 inhibitors increase glucagon secretion via direct inhibition of SGLT2 in pancreatic α cells. The role of SGLT1 in α cells is also unclear. We aimed to elucidate these points that are important not only for basic research but also for clinical insight.
Methods: Plasma glucagon levels were assessed in the high-fat, high-sucrose diet (HFHSD) fed C57BL/6J mice treated with dapagliflozin or canagliflozin. RT-PCR, RNA sequence, and immunohistochemistry were conducted to test the expression of SGLT1 and SGLT2 in α cells. We also used αTC1 cells and mouse islets to investigate the molecular mechanism by which SGLT1 modulates glucagon secretion.
Results: Dapagliflozin, but not canagliflozin, increased plasma glucagon levels in HFHSD fed mice. SGLT1 and glucose transporter 1 (GLUT1), but not SGLT2, were expressed in αTC1 cells, mouse islets and human islets. A glucose clamp study revealed that the plasma glucagon increase associated with dapagliflozin could be explained as a response to acute declines in blood glucose. Canagliflozin suppressed glucagon secretion by inhibiting SGLT1 in α cells; consequently, plasma glucagon did not increase with canagliflozin, even though blood glucose declined. SGLT1 effect on glucagon secretion depended on glucose transport, but not glucose metabolism. Islets from HFHSD and db/db mice displayed higher SGLT1 mRNA levels and lower GLUT1 mRNA levels than the islets from control mice. These expression levels were associated with higher glucagon secretion. Furthermore, SGLT1 inhibitor and siRNA against SGLT1 suppressed glucagon secretion in isolated islets.
Conclusions: These data suggested that a novel mechanism regulated glucagon secretion through SGLT1 in α cells. This finding possibly explained the distinct effects of dapagliflozin and canagliflozin on plasma glucagon levels in mice.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6323192 | PMC |
http://dx.doi.org/10.1016/j.molmet.2018.10.009 | DOI Listing |
World J Gastroenterol
December 2024
Department of Cardiology, Dayanand Medical College and Hospital, Ludhiana 141001, Punjab, India.
The global prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is estimated at 32.4%, reflecting its growing clinical significance. MASLD, which includes MASLD and metabolic dysfunction-associated steatohepatitis (MASH) has been linked to increased metabolic, cardiovascular, and malignant morbidity.
View Article and Find Full Text PDFCardiovasc Diabetol
December 2024
Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave, s7-119, New York, NY, USA.
Background: Long-term consumption of Western Diet (WD) is a well-established risk factor for the development of cardiovascular disease (CVD); however, there is a paucity of studies on the long-term effects of WD on the pathophysiology of CVD and sex-specific responses.
Methods: Our study aimed to investigate the sex-specific pathophysiological changes in left ventricular (LV) function using transthoracic echocardiography (ECHO) and LV tissue transcriptomics in WD-fed C57BL/6 J mice for 125 days, starting at the age of 300 through 425 days.
Results: In female mice, consumption of the WD diet showed long-term effects on LV structure and possible development of HFpEF-like phenotype with compensatory cardiac structural changes later in life.
J Pharm Biomed Anal
December 2024
Institute of Traditional Chinese Medicine, Shaanxi Academy of Traditional Chinese Medicine, Xi'an, Shaanxi, China; Key Laboratory of TCM Drug Delivery, Shaanxi Academy of Traditional Chinese Medicine, Xi'an, Shaanxi, China. Electronic address:
Pharmacologic intervention in chronic heart failure (HF) with renal insufficiency is one of the clinical challenges due to the fact that the mechanisms of cardio-renal interactions in chronic heart failure (CHF) progressing have not been fully revealed. In this paper, C57BL/6 mice were applied thoracic aortic narrowing surgery to establish pressure overload CHF model. Cardiac function, serum markers, renal pathologic changes and kidney metabolism were analyzed at 4th, 8th, 12th, and 16th week after surgery respectively to evaluate the heart-Kidney pathologic overlap.
View Article and Find Full Text PDFCurr Issues Mol Biol
December 2024
1st Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens, Hippokration General Hospital, 11527 Athens, Greece.
Initially intended to control blood glucose levels in patients with type 2 diabetes, semaglutide, a potent glucagon-like peptide 1 analogue, has been established as an effective weight loss treatment by controlling appetite. Integrating the latest clinical trials, semaglutide in patients with or without diabetes presents significant therapeutic efficacy in ameliorating cardiometabolic risk factors and physical functioning, independent of body weight reduction. Semaglutide may modulate adipose tissue browning, which enhances human metabolism and exhibits possible benefits in skeletal muscle degeneration, accelerated by obesity and ageing.
View Article and Find Full Text PDFAm J Pathol
December 2024
Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510080, China. Electronic address:
This study aimed to investigate the expression of glucagon-like peptide 1 receptor (GLP-1R) in the lacrimal gland and explore the effects of topical application of GLP-1R agonist (GLP-1RA) on lacrimal gland function in a murine model of type 1 diabetes. Tear secretion was evaluated using phenol red threads, RNA sequencing (RNA-seq) was used to explore gene expression profiles associated with hyperglycemia-induced lacrimal gland injuries, and histological analysis was conducted to evaluate the degree of damage. The expression of GLP-1R in the lacrimal gland was first identified and a downregulation trend associated with diabetes was observed.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!