GLP-1 metabolite GLP-1(9-36) is a systemic inhibitor of mouse and human pancreatic islet glucagon secretion

Glucagon-Like Peptide 1 Receptor Agonists (GLP-1RAs) Improve Periodontal and Peri-Implant Health in Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) affects millions globally and is strongly associated with oral health issues, particularly periodontitis. The bidirectional relationship between T2DM and periodontitis is well established, with poorly managed T2DM increasing the risk of inflammation, tissue damage, and dental implant failure. Advances in treatment, such as glucagon-like peptide 1 receptor agonists (GLP-1RAs), have led to better glycemic control and may reduce T2DM-related complications, highlighting their potential in addressing interconnected oral-systemic health challenges. This narrative review critically evaluates the literature on the impact of GLP-1RAs on periodontal and peri-implant health. 10 in vitro studies, nine preclinical animal studies, and one clinical study were explored to investigate their effects on periodontal regeneration, implant therapy, and related mechanisms. In vitro research revealed that GLP-1RAs, including exenatide and liraglutide, promoted osteogenic differentiation of periodontal ligament stem cells (PDLSCs) through pathways such as the mitogen Wnt/β-catenin and mitogen-activated protein kinase pathways, even in high glucose or inflammatory conditions. Synergistic effects with stromal cell-derived factor-1 further promoted PDLSC proliferation and bone regeneration. Animal studies demonstrated that GLP-1RAs mitigated periodontal inflammation, oxidative stress, and alveolar bone resorption while promoting bone remodeling and implant osseointegration, independently of glycemic control. Importantly, advanced delivery systems, such as exenatide-loaded chitosan-poly(lactic-coglycolic acid) microspheres, further increased peri-implant osseointegration in diabetic models. The sole clinical study, a retrospective cohort study, assessed peri-implant marginal bone loss in peri-implantitis patients treated with different hypoglycemic drugs. Results showed significantly less clinical and radiographic bone loss in the GLP-1RA group compared to insulin and metformin groups (p < 0.01). Overall, while GLP-1RAs have promising anti-inflammatory, osteoprotective, and pleiotropic properties, their role appears more aligned with preserving periodontal and peri-implant health in T2DM individuals than directly treating periodontitis or peri-implantitis. By delineating current evidence and research directions, this review calls for medical and dental professionals to collaborate in leveraging these novel treatment options in future studies to improve patient care and address the intricate challenges that diabetes presents to oral health.

Structural pharmacology and mechanisms of GLP-1R signaling

Glucagon-like peptide-1 receptor (GLP-1R), a class B1 G protein-coupled receptor, plays critical roles in glucose homeostasis. Recent structural pharmacology studies using cryogenic electron microscopy, X-ray crystallography, mass spectrometry, and functional analyses, have provided valuable insights into its activation by endogenous hormones and mono- or dual agonists like semaglutide and tirzepatide, highly effective in treating type 2 diabetes and obesity. They highlight significant conformational changes in the extracellular and transmembrane domains of GLP-1R that drive receptor activation and downstream signal transduction. Additionally, allosteric modulators, supported by emerging structural information, show great promises as an alternative strategy. Future research investigating unexplored effector interactions, biased signaling, weight rebound mechanisms, and personalized therapy strategies will be critical for developing better therapeutic agents targeting GLP-1R.

Research progress of GLP-1RAs in the treatment of type 2 diabetes mellitus

Glucagon-like peptide-1 (GLP-1) is a 30-amino acid intestinal insulin-stimulating factor, which is mainly secreted by L cells in the distal ileum and colon. It has various physiological functions, such as promoting insulin secretion and synthesis, stimulating β-cell proliferation, inducing islet regeneration, inhibiting β-cell apoptosis and glucagon release, delaying gastric emptying and controlling appetite, etc. It plays a role through a specific GLP-1 receptor (GLP-1R) distributed in many organs or tissues and participates in the regulation of glucose homeostasis in the body. GLP-1 receptor agonists (GLP-1RAs) has the similar physiological function of GLP-1. Because of its structural difference from natural GLP-1, it is not easy to be degraded by dipeptidyl peptidase-4 (DPP-4), thus prolonging the action time. GLP-1RAs have been recognized as a new type of hypoglycemic drugs and widely used in the treatment of type 2 diabetes mellitus (T2DM). Compared with other non-insulin hypoglycemic drugs, it can not only effectively reduce blood glucose and glycosylated hemoglobin (HbA1c), but also protect cardiovascular system, nervous system and kidney function without causing hypoglycemia and weight gain. Therefore, GLP-1RAs has good application prospects and potential for further development.

[From the discovery of incretin hormones to GIP / GLP-1 / glucagon double and triple agonists]

The concept of treating diabetes with gut hormones was proposed in the early days of endocrinology (1902), but was not put into practice until the early 2000s. The discovery of the incretin effect (potentiation of insulin secretion when glucose is taken orally compared to intravenously) led to the discovery of the two main gut hormones responsible for this effect: GIP and GLP-1. The reduction of the incretin effect is directly involved in the pathogenesis of type 2 diabetes, which has led to the development of a series of innovative therapies such as GLP-1 analogues, GLP-1 receptor agonists, GIP/GLP-1 co-agonists and GIP/GLP-1/glucagon tri-agonists. These therapies, with their potent hypoglycaemic and weight-lowering effects, promote optimal control of excess weight and hyperglycaemia, avoiding the escalation of treatment that was once considered inevitable.

Glucagon-like peptide-1 receptor: mechanisms and advances in therapy

The glucagon-like peptide-1 (GLP-1) receptor, known as GLP-1R, is a vital component of the G protein-coupled receptor (GPCR) family and is found primarily on the surfaces of various cell types within the human body. This receptor specifically interacts with GLP-1, a key hormone that plays an integral role in regulating blood glucose levels, lipid metabolism, and several other crucial biological functions. In recent years, GLP-1 medications have become a focal point in the medical community due to their innovative treatment mechanisms, significant therapeutic efficacy, and broad development prospects. This article thoroughly traces the developmental milestones of GLP-1 drugs, from their initial discovery to their clinical application, detailing the evolution of diverse GLP-1 medications along with their distinct pharmacological properties. Additionally, this paper explores the potential applications of GLP-1 receptor agonists (GLP-1RAs) in fields such as neuroprotection, anti-infection measures, the reduction of various types of inflammation, and the enhancement of cardiovascular function. It provides an in-depth assessment of the effectiveness of GLP-1RAs across multiple body systems-including the nervous, cardiovascular, musculoskeletal, and digestive systems. This includes integrating the latest clinical trial data and delving into potential signaling pathways and pharmacological mechanisms. The primary goal of this article is to emphasize the extensive benefits of using GLP-1RAs in treating a broad spectrum of diseases, such as obesity, cardiovascular diseases, non-alcoholic fatty liver disease (NAFLD), neurodegenerative diseases, musculoskeletal inflammation, and various forms of cancer. The ongoing development of new indications for GLP-1 drugs offers promising prospects for further expanding therapeutic interventions, showcasing their significant potential in the medical field.

Unraveling the mechanisms of hepatogenous diabetes and its therapeutic perspectives

The review focused mainly on the pathogenesis of hepatogenous diabetes (HD) in liver cirrhosis (LC). This review reveals parallels between the mechanisms of metabolic dysfunction observed in LC and type II diabetes (T2DM), suggesting a shared pathway leading to HD. It underscores the role of insulin in HD pathogenesis, highlighting key factors such as insulin signaling, glucose metabolism, insulin resistance (IR), and the influence of adipocytes. Furthermore, the impact of adipose tissue accumulation, fatty acid metabolism, and pro-inflammatory cytokines like Tumor necrosis factor-α (TNF-α) on IR are discussed in the context of HD. Altered signaling pathways, disruptions in the endocrine system, liver inflammation, changes in muscle mass and composition, and modifications to the gut microbiota collectively contribute to the complex interplay linking cirrhosis and HD. This study highlights how important it is to identify and treat this complex condition in cirrhotic patients by thoroughly analyzing the link between cirrhosis, IR, and HD. It also emphasizes the vitality of targeted interventions. Cellular and molecular investigations into IR have revealed potential therapeutic targets for managing and preventing HD.

Impact of a 12-Week Dietary Intervention on Adipose Tissue Metabolic Markers in Overweight Women of Reproductive Age

The prevalence of overweight and obesity in women of reproductive age leads to significant health risks, including adverse metabolic and reproductive outcomes. Effective dietary interventions are critical to improving health outcomes in this population. This study investigates the impact of a 12-week diet intervention on metabolic markers of adipose tissue in overweight women of reproductive age, determining whether calorie restriction or low-starch diets are more effective, while also accounting for salivary amylase activity. A total of 67 overweight women of reproductive age were enrolled in a randomized controlled trial (RCT). Participants were divided into high-salivary-amylase (HSA) and low-salivary-amylase (LSA) groups based on baseline salivary amylase activity measured using a spectrophotometric method. Each group was further subdivided into two dietary intervention groups: calorie restriction (CR) and low starch (LS), resulting in four subgroups (HSA-CR, HSA-LS, LSA-CR, LSA-LS), along with a control group (CTR) of normal-weight individuals (no intervention). Participants were assigned to a calorie-restricted diet or a low-starch diet for 12 weeks. Key metabolic markers of adipose tissue, including insulin sensitivity, adipokines, cytokines, and lipid profiles, were measured at baseline (T0), 30 min after consuming starch-containing muesli (T1), and 12 weeks after intervention (T2). Active GLP-1, glucagon, and C-peptide levels were assessed to clarify the hormonal mechanisms underlying the dietary effects. Salivary amylase activity was also measured to examine its role in modulating glucose and GLP-1 responses. Both diet interventions led to significant improvements in metabolic markers of adipose tissue, though different ones. Calorie restriction improved insulin sensitivity by effectively reducing visceral fat mass and enhancing insulin signaling pathways. In contrast, the low-starch diet was linked to a reduction in the coefficient of glucose variation influenced partly by changes in GLP-1 levels. Our findings highlight the importance of personalized diet strategies to optimize metabolic health in this demographic.

Examining the Potential Applicability of Orexigenic and Anorexigenic Peptides in Veterinary Medicine for the Management of Obesity in Companion Animals

This review article comprehensively explores the role of orexigenic and anorexigenic peptides in the management of obesity in companion animals, with a focus on clinical applications. Obesity in domestic animals, particularly dogs and cats, is prevalent, with significant implications for their health and well-being. Factors contributing to obesity include overfeeding, poor-quality diet, lack of physical activity, and genetic predispositions. Despite the seriousness of this condition, it is often underestimated, with societal perceptions sometimes reinforcing unhealthy behaviors. Understanding the regulation of food intake and identifying factors affecting the function of food intake-related proteins are crucial in combating obesity. Dysregulations in these proteins, whether due to genetic mutations, enzymatic dysfunctions, or receptor abnormalities, can have profound health consequences. Molecular biology techniques play a pivotal role in elucidating these mechanisms, offering insights into potential therapeutic interventions. The review categorizes food intake-related proteins into anorexigenic peptides (inhibitors of food intake) and orexigenic peptides (enhancers of food intake). It thoroughly examines current research on regulating energy balance in companion animals, emphasizing the clinical application of various peptides, including ghrelin, phoenixin (PNX), asprosin, glucagon-like peptide 1 (GLP-1), leptin, and nesfatin-1, in veterinary obesity management. This comprehensive review aims to provide valuable insights into the complex interplay between peptides, energy balance regulation, and obesity in companion animals. It underscores the importance of targeted interventions and highlights the potential of peptide-based therapies in improving the health outcomes of obese pets.

The Importance of Intra-Islet Communication in the Function and Plasticity of the Islets of Langerhans during Health and Diabetes

Islets of Langerhans are anatomically dispersed within the pancreas and exhibit regulatory coordination between islets in response to nutritional and inflammatory stimuli. However, within individual islets, there is also multi-faceted coordination of function between individual beta-cells, and between beta-cells and other endocrine and vascular cell types. This is mediated partly through circulatory feedback of the major secreted hormones, insulin and glucagon, but also by autocrine and paracrine actions within the islet by a range of other secreted products, including somatostatin, urocortin 3, serotonin, glucagon-like peptide-1, acetylcholine, and ghrelin. Their availability can be modulated within the islet by pericyte-mediated regulation of microvascular blood flow. Within the islet, both endocrine progenitor cells and the ability of endocrine cells to trans-differentiate between phenotypes can alter endocrine cell mass to adapt to changed metabolic circumstances, regulated by the within-islet trophic environment. Optimal islet function is precariously balanced due to the high metabolic rate required by beta-cells to synthesize and secrete insulin, and they are susceptible to oxidative and endoplasmic reticular stress in the face of high metabolic demand. Resulting changes in paracrine dynamics within the islets can contribute to the emergence of Types 1, 2 and gestational diabetes.