Chronic elevations in plasma levels of fatty acids (FAs) adversely affect pancreatic beta-cell function in type 2 diabetes. In vitro, we have previously shown that deleterious effects of prolonged exposure of isolated islets to FAs were dependent on the presence of elevated glucose concentration. This led us to hypothesize that both hyperlipidemia and hyperglycemia must be present simultaneously for FAs to affect beta-cell function. To test this hypothesis in vivo, we administered a high-fat diet for 6 weeks to Goto-Kakizaki (GK) rats. High-fat feeding had no effect on insulin secretion, insulin content, or insulin mRNA levels in islets from normoglycemic Wistar rats. In contrast, high-fat feeding markedly impaired glucose-induced insulin secretion in islets from GK rats. High-fat feeding did not affect triglyceride (TG) content or the rate of glucose oxidation in islets. It was, however, accompanied by a twofold increase in uncoupling protein (UCP)-2 levels in GK rat islets. Insulin treatment completely normalized glucose-induced insulin secretion and prevented the increase in UCP-2 expression in islets from high-fat-fed GK rats. We conclude that hyperlipidemia induced by high-fat feeding affects insulin secretion in islets from hyperglycemic GK rats only, by a mechanism which may involve, at least in part, modulation of UCP-2 expression.
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http://dx.doi.org/10.2337/diabetes.51.3.662 | DOI Listing |
Cell Mol Life Sci
January 2025
Department of Endocrinology, Central South University Third Xiangya Hospital, Changsha, China.
Pancreatic β-cell damage is a critical pathological mechanism in the progression of obese type 2 diabetes mellitus (T2DM). However, the exact underlying mechanism remains unclear. We established an obese T2DM mouse model via high-fat diet feeding.
View Article and Find Full Text PDFPLoS Biol
January 2025
Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) CCT UNS-CONICET, Bahía Blanca, Argentina.
The DAF-2/insulin/insulin-like growth factor signaling (IIS) pathway plays an evolutionarily conserved role in regulating reproductive development, life span, and stress resistance. In Caenorhabditis elegans, DAF-2/IIS signaling is modulated by an extensive array of insulin-like peptides (ILPs) with diverse spatial and temporal expression patterns. However, the release dynamics and specific functions of these ILPs in adapting to different environmental conditions remain poorly understood.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
January 2025
Department of Endocrinology, Key Laboratory of Endocrinology, State Key Laboratory of Complex Severe and Rare Diseases, Dongcheng District, National Commission of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
Context: Phosphate homeostasis was compromised in tumor-induced osteomalacia (TIO) due to increased fibroblast growth factor 23 (FGF23) secretion. Nevertheless, the glucose metabolic profile in TIO patients has not been investigated.
Objectives: This work aimed to clarify the glucose metabolic profiles in TIO patients and explore their interaction with impaired phosphate homeostasis.
Nat Prod Res
January 2025
Department of Pharmacognosy and Medicinal Plants, Faculty of Pharmacy, Al-Azhar University (Boys), Cairo, Egypt.
The herbal extracts of four traditional plants; namely leaves, fruits leaves, and seeds, were identified for their main constituents using UHPLC/QTOF-MS/MS. Then, a pharmacology-based analysis and molecular docking verification were established targeting the evaluation of each individual herbal extract for their antidiabetic/anti-obesity potential besides their safety. Streptozotocin-induced diabetic rats were used to evaluate antiobesity and insulinotropic effects against insulin (10 U/Kg, IP) and metformin (100 mg/Kg, per oral) as standard regimens.
View Article and Find Full Text PDFLife Metab
December 2024
Department of Endocrinology and Metabolism, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai 200233, China.
Type 2 diabetes mellitus (T2DM) is closely associated with obesity, while interactions between the two diseases remain to be fully elucidated. To this point, we offer this perspective to introduce a set of new insights into the interpretation of T2DM spanning the etiology, pathogenesis, and treatment approaches. These include a definition of T2DM as an energy surplus-induced diabetes characterized by the gradual decline of β cell insulin secretion function, which ultimately aims to prevent the onset of severe obesity through mechanisms of weight loss.
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