ABSTRACT
Functional genetics has identified drug targets for metabolic disorders. Opioid use impacts metabolic homeostasis, although mechanisms remain elusive. Here, we explore the OPRD1 gene (encoding delta opioid receptor, DOP) to understand its impact on type 2 diabetes. Large-scale sequencing of OPRD1 and in vitro analysis reveal that loss-of-function variants are associated with higher adiposity and lower hyperglycemia risk, whereas gain-of-function variants are associated with lower adiposity and higher type 2 diabetes risk. These findings align with studies of opium addicts. OPRD1 is expressed in human islets and beta cells, with decreased expression under type 2 diabetes conditions. DOP inhibition by an antagonist enhances insulin secretion from human beta cells and islets. RNA-sequencing identifies pathways regulated by DOP antagonism, including nerve growth factor, circadian clock, and nuclear receptor pathways. Our study highlights DOP as a key player between opioids and metabolic homeostasis, suggesting its potential as a therapeutic target for type 2 diabetes.
Subject(s)
Diabetes Mellitus, Type 2 , Insulin-Secreting Cells , Receptors, Opioid, delta , Receptors, Opioid, delta/metabolism , Receptors, Opioid, delta/genetics , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Humans , Insulin-Secreting Cells/metabolism , Male , Female , Middle Aged , Insulin/metabolism , Insulin Secretion/drug effects , Insulin Secretion/genetics , AdultABSTRACT
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are two incretins that bind to their respective receptors and activate the downstream signaling in various tissues and organs. Both GIP and GLP-1 play roles in regulating food intake by stimulating neurons in the brain's satiety center. They also stimulate insulin secretion in pancreatic ß-cells, but their effects on glucagon production in pancreatic α-cells differ, with GIP having a glucagonotropic effect during hypoglycemia and GLP-1 exhibiting glucagonostatic effect during hyperglycemia. Additionally, GIP directly stimulates lipogenesis, while GLP-1 indirectly promotes lipolysis, collectively maintaining healthy adipocytes, reducing ectopic fat distribution, and increasing the production and secretion of adiponectin from adipocytes. Together, these two incretins contribute to metabolic homeostasis, preventing both hyperglycemia and hypoglycemia, mitigating dyslipidemia, and reducing the risk of cardiovascular diseases in individuals with type 2 diabetes and obesity. Several GLP-1 and dual GIP/GLP-1 receptor agonists have been developed to harness these pharmacological effects in the treatment of type 2 diabetes, with some demonstrating robust effectiveness in weight management and prevention of cardiovascular diseases. Elucidating the underlying cellular and molecular mechanisms could potentially usher in the development of new generations of incretin mimetics with enhanced efficacy and fewer adverse effects. The treatment guidelines are evolving based on clinical trial outcomes, shaping the management of metabolic and cardiovascular diseases.
Subject(s)
Diabetes Mellitus, Type 2 , Gastric Inhibitory Polypeptide , Glucagon-Like Peptide 1 , Glucagon-Like Peptide-1 Receptor Agonists , Receptors, Gastrointestinal Hormone , Animals , Humans , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Gastric Inhibitory Polypeptide/therapeutic use , Glucagon-Like Peptide 1/metabolism , Glucagon-Like Peptide 1/agonists , Glucagon-Like Peptide-1 Receptor Agonists/pharmacology , Glucagon-Like Peptide-1 Receptor Agonists/therapeutic use , Hypoglycemic Agents/therapeutic use , Hypoglycemic Agents/pharmacology , Incretins/therapeutic use , Incretins/pharmacology , Receptors, Gastrointestinal Hormone/agonists , Receptors, Gastrointestinal Hormone/metabolismABSTRACT
Objective: The causal relationship between type 2 diabetes mellitus (T2DM) and osteoporosis (OS) remains unclear. This study aims to investigate the causal relationship and explore the potential metabolic mechanism and its mediating role. Methods: We conducted a comprehensive study, gathering data on 490,089 T2DM patients from the genome-wide association study (GWAS) database and selecting OS data from FinnGen and MRC-IEU sources, including 212,778 and 463,010 patients, respectively, for causal analysis. Simultaneously, we explored the potential roles of three obesity traits and 30 metabolic and inflammation-related mediating variables in the causal relationship. Results: There is a strong causal relationship between T2DM and OS. The data from our two different database sources appeared in the same direction, but after correcting for body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR), the direction became the same. T2DM may increase the risk of OS [odds ratio (OR) > 1.5, p < 0.001]. Steiger's test results show that there is no reverse causality. No risk factors related to glycolipid metabolism, amino acid metabolism, and inflammation were found to mediate the causal relationship. Conclusion: This study's findings indicate a robust causal relationship between T2DM and OS, influenced by relevant factors such as BMI. Our results shed light on the pathogenesis of OS and underscore the importance for clinicians to treat metabolic disorders to prevent osteoporosis.
Subject(s)
Diabetes Mellitus, Type 2 , Genome-Wide Association Study , Osteoporosis , Humans , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/complications , Osteoporosis/metabolism , Osteoporosis/etiology , Female , Male , Middle Aged , Risk Factors , Body Mass Index , Aged , Waist Circumference , Obesity/complications , Obesity/metabolism , Waist-Hip RatioABSTRACT
Neuroinflammation, aging, and neurodegenerative disorders are associated with excessive accumulation of neutral lipids in lipid droplets (LDs) in microglia. Type 2 diabetes mellitus (T2DM) may cause neuroinflammation and is a risk factor for neurodegenerative disorders. Here, we show that hippocampal pyramidal neurons contain smaller, more abundant LDs than their neighboring microglia. The density of LDs varied between pyramidal cells in adjacent subregions, with CA3 neurons containing more LDs than CA1 neurons. Within the CA3 region, a gradual increase in the LD content along the pyramidal layer from the hilus toward CA2 was observed. Interestingly, the high neuronal LD content correlated with less ramified microglial morphotypes. Using the db/db model of T2DM, we demonstrated that diabetes increased the number of LDs per microglial cell without affecting the neuronal LD density. High-intensity interval exercise induced smaller changes in the number of LDs in microglia but was not sufficient to counteract the diabetes-induced changes in LD accumulation. The changes observed in response to T2DM may contribute to the cerebral effects of T2DM and provide a mechanistic link between T2DM and neurodegenerative disorders.
Subject(s)
Diabetes Mellitus, Type 2 , Hippocampus , Lipid Droplets , Microglia , Neurons , Microglia/metabolism , Animals , Lipid Droplets/metabolism , Hippocampus/metabolism , Hippocampus/pathology , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/pathology , Neurons/metabolism , Neurons/pathology , Male , Mice , Physical Conditioning, Animal , Pyramidal Cells/metabolism , Pyramidal Cells/pathology , Mice, Inbred C57BL , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Lipid Metabolism , Neuroinflammatory Diseases/metabolism , Neuroinflammatory Diseases/pathologyABSTRACT
BACKGROUND: Diabetes mellitus (DM) is a global metabolic problem. Several factors including hyperglycemia, oxidative stress, and inflammation play significant roles in the development of DM complications. Apoptosis is also an essential event in DM pathophysiology, -with B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X (Bax) determining apoptotic susceptibility. The present study aimed to elucidate the protective effects of two doses of taxifolin (TXF) on liver damage in diabetic rats and explore the possible mechanisms of action. METHODS AND RESULTS: DM was induced in eighteen rats through intraperitoneal injections of 50 mg/kg streptozotocin and 110 mg/kg nicotinamide. Diabetic rats received daily oral intubation of 25 and 50 mg/kg TXF for 3 months. In the untreated diabetic group, there was a significant increase in fasting and postprandial glucose levels, glycosylated hemoglobin A1C (HbA1c), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6), while insulin and adiponectin levels decreased significantly. Both TXF doses mitigated hyperglycemia, regulated cytokine production, and increased insulin level. Gene expressions and protein levels of Bax, caspase 3, and cytochrome c were significantly increased, while Bcl-2 was significantly decreased in the livers of diabetic rats, effects that were significantly ameliorated after TXF treatment. The results of the TUNEL assay supported the apoptotic pathway. Additionally, TXF significantly decreased lipid peroxidation and enhanced antioxidant enzyme activity in diabetic rats. Liver enzymes and histopathological changes also showed improvement. CONCLUSIONS: TXF mitigated diabetes-associated hepatic damage by reducing hyperglycemia, oxidative stress, inflammation, and modulating anti-/pro-apoptotic genes and proteins. A dose of 50 mg/kg TXF was more effective than 25 mg/kg and is recommended for consumption.
Subject(s)
Apoptosis , Caspase 3 , Diabetes Mellitus, Experimental , Liver , Oxidative Stress , Proto-Oncogene Proteins c-bcl-2 , Quercetin , Signal Transduction , bcl-2-Associated X Protein , Animals , Quercetin/pharmacology , Quercetin/analogs & derivatives , Quercetin/therapeutic use , Oxidative Stress/drug effects , Rats , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/complications , Signal Transduction/drug effects , Male , Caspase 3/metabolism , Caspase 3/genetics , bcl-2-Associated X Protein/metabolism , bcl-2-Associated X Protein/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Proto-Oncogene Proteins c-bcl-2/genetics , Apoptosis/drug effects , Liver/drug effects , Liver/metabolism , Liver/pathology , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/complications , Blood Glucose/metabolism , Blood Glucose/drug effects , Insulin/metabolismABSTRACT
BACKGROUND: Type 2 diabetes mellitus (T2D) is associated with an increased risk of cognitive dysfunction. Angiopoietin-like protein 8 (ANGPTL8) is an important regulator in T2D, but the role of ANGPTL8 in diabetes-associated cognitive dysfunction remains unknown. Here, we explored the role of ANGPTL8 in diabetes-associated cognitive dysfunction through its interaction with paired immunoglobulin-like receptor B (PirB) in the central nervous system. METHODS: The levels of ANGPTL8 in type 2 diabetic patients with cognitive dysfunction and control individuals were measured. Mouse models of diabetes-associated cognitive dysfunction were constructed to investigate the role of ANGPTL8 in cognitive function. The cognitive function of the mice was assessed by the Barnes Maze test and the novel object recognition test, and levels of ANGPTL8, synaptic and axonal markers, and pro-inflammatory cytokines were measured. Primary neurons and microglia were treated with recombinant ANGPTL8 protein (rA8), and subsequent changes were examined. In addition, the changes induced by ANGPTL8 were validated after blocking PirB and its downstream pathways. Finally, mice with central nervous system-specific knockout of Angptl8 and PirB-/- mice were generated, and relevant in vivo experiments were performed. RESULTS: Here, we demonstrated that in the diabetic brain, ANGPTL8 was secreted by neurons into the hippocampus, resulting in neuroinflammation and impairment of synaptic plasticity. Moreover, neuron-specific Angptl8 knockout prevented diabetes-associated cognitive dysfunction and neuroinflammation. Mechanistically, ANGPTL8 acted in parallel to neurons and microglia via its receptor PirB, manifesting as downregulation of synaptic and axonal markers in neurons and upregulation of proinflammatory cytokine expression in microglia. In vivo, PirB-/- mice exhibited resistance to ANGPTL8-induced neuroinflammation and synaptic damage. CONCLUSION: Taken together, our findings reveal the role of ANGPTL8 in the pathogenesis of diabetes-associated cognitive dysfunction and identify the ANGPTL8-PirB signaling pathway as a potential target for the management of this condition.
Subject(s)
Angiopoietin-Like Protein 8 , Angiopoietin-like Proteins , Cognitive Dysfunction , Diabetes Mellitus, Type 2 , Mice, Knockout , Receptors, Immunologic , Signal Transduction , Animals , Mice , Cognitive Dysfunction/metabolism , Cognitive Dysfunction/prevention & control , Cognitive Dysfunction/etiology , Signal Transduction/physiology , Signal Transduction/drug effects , Angiopoietin-like Proteins/metabolism , Angiopoietin-like Proteins/genetics , Humans , Male , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/metabolism , Receptors, Immunologic/metabolism , Receptors, Immunologic/genetics , Mice, Inbred C57BL , Synapses/metabolism , Synapses/pathology , Synapses/drug effects , Peptide Hormones/metabolism , Middle Aged , FemaleABSTRACT
Insulin resistance (IR) is a complex pathological condition central to metabolic diseases such as type 2 diabetes mellitus (T2DM), cardiovascular disease, non-alcoholic fatty liver disease, and polycystic ovary syndrome (PCOS). This review evaluates the impact of lipids on insulin resistance (IR) by analyzing findings from human and animal studies. The articles were searched on the PubMed database using two keywords: (1) "Role of Lipids AND Insulin Resistance AND Humans" and (2) "Role of Lipids AND Insulin Resistance AND Animal Models". Studies in humans revealed that elevated levels of free fatty acids (FFAs) and triglycerides (TGs) are closely associated with reduced insulin sensitivity, and interventions like metformin and omega-3 fatty acids show potential benefits. In animal models, high-fat diets disrupt insulin signaling and increase inflammation, with lipid mediators such as diacylglycerol (DAG) and ceramides playing significant roles. DAG activates protein kinase C, which eventually impairs insulin signaling, while ceramides inhibit Akt/PKB, further contributing to IR. Understanding these mechanisms is crucial for developing effective prevention and treatment strategies for IR-related diseases.
Subject(s)
Insulin Resistance , Humans , Animals , Lipids/blood , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Disease Models, Animal , Signal Transduction/drug effectsABSTRACT
The lack of an appropriate preclinical model of metabolic dysfunction-associated steatotic liver disease (MASLD) that recapitulates the whole disease spectrum impedes exploration of disease pathophysiology and the development of effective treatment strategies. Here, we develop a mouse model (Streptozotocin with high-fat diet, STZ + HFD) that gradually develops fatty liver, metabolic dysfunction-associated steatohepatitis (MASH), hepatic fibrosis, and hepatocellular carcinoma (HCC) in the context of metabolic dysfunction. The hepatic transcriptomic features of STZ + HFD mice closely reflect those of patients with obesity accompanying type 2 diabetes mellitus, MASH, and MASLD-related HCC. Dietary changes and tirzepatide administration alleviate MASH, hepatic fibrosis, and hepatic tumorigenesis in STZ + HFD mice. In conclusion, a murine model recapitulating the main histopathologic, transcriptomic, and metabolic alterations observed in MASLD patients is successfully established.
Subject(s)
Carcinoma, Hepatocellular , Diet, High-Fat , Disease Models, Animal , Liver Neoplasms , Animals , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/genetics , Male , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Liver Neoplasms/genetics , Mice , Diet, High-Fat/adverse effects , Mice, Inbred C57BL , Humans , Liver/metabolism , Liver/pathology , Fatty Liver/metabolism , Fatty Liver/pathology , Streptozocin , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Transcriptome , Obesity/metabolism , Obesity/complications , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/metabolism , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/pathology , Non-alcoholic Fatty Liver Disease/complicationsABSTRACT
BACKGROUND: Atherosclerosis (AS) is a progressive disease that interferes with blood flow, leading to cardiovascular complications such as hypertension, ischemic heart disease, ischemic stroke, and vascular ischemia. The progression of AS is correlated with inflammation, oxidative stress, and endothelial dysfunction. Various signaling pathways, like nuclear erythroid-related factor 2 (Nrf2) and Kruppel-like factor 2 (KLF2), are involved in the pathogenesis of AS. Nrf2 and KLF2 have anti-inflammatory and antioxidant properties. Thus, activation of these pathways may reduce the development of AS. Metformin, an insulin-sensitizing drug used in the management of type 2 diabetes mellitus (T2DM), increases the expression of Nrf2 and KLF2. AS is a common long-term macrovascular complication of T2DM. Thus, metformin, through its pleiotropic anti-inflammatory effect, may attenuate the development and progression of AS. AIMS: Therefore, this review aims to investigate the possible role of metformin in AS concerning its effect on Nrf2 and KLF2 and inhibition of reactive oxygen species (ROS) formation. In addition to its antidiabetic effect, metformin can reduce cardiovascular morbidities and mortalities compared to other antidiabetic agents, even with similar blood glucose control by the Nrf2/KLF2 pathway activation. CONCLUSION: In conclusion, metformin is an effective therapeutic strategy against the development and progression of AS, mainly through activation of the KLF2/Nrf2 axis.
Subject(s)
Atherosclerosis , Diabetes Mellitus, Type 2 , Hypoglycemic Agents , Kruppel-Like Transcription Factors , Metformin , NF-E2-Related Factor 2 , Metformin/therapeutic use , Metformin/pharmacology , Humans , Atherosclerosis/drug therapy , Atherosclerosis/metabolism , Hypoglycemic Agents/therapeutic use , Hypoglycemic Agents/pharmacology , Kruppel-Like Transcription Factors/metabolism , NF-E2-Related Factor 2/metabolism , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/complications , Animals , Oxidative Stress/drug effects , Signal Transduction/drug effects , Reactive Oxygen Species/metabolismABSTRACT
It is well established that high-protein diets (i.e. ~25-30% of energy intake from protein) provide benefits for achieving weight loss, and subsequent weight maintenance, in individuals with obesity, and improve glycemic control in type 2 diabetes (T2D). These effects may be attributable to the superior satiating property of protein, at least in part, through stimulation of both gastrointestinal (GI) mechanisms by protein, involving GI hormone release and slowing of gastric emptying, as well as post-absorptive mechanisms facilitated by circulating amino acids. In contrast, there is evidence that the beneficial effects of greater protein intake on body weight and glycemia may only be sustained for 6-12 months. While both suboptimal dietary compliance and metabolic adaptation, as well as substantial limitations in the design of longer-term studies are all likely to contribute to this contradiction, the source of dietary protein (i.e. animal vs. plant) has received inappropriately little attention. This issue has been highlighted by outcomes of recent epidemiological studies indicating that long-term consumption of animal-based protein may have adverse effects in relation to the development of obesity and T2D, while plant-based protein showed either protective or neutral effects. This review examines information relating to the effects of dietary protein on appetite, energy intake and postprandial glycemia, and the relevant GI functions, as reported in acute, intermediate- and long-term studies in humans. We also evaluate knowledge relating to the relevance of the dietary protein source, specifically animal or plant, to the prevention, and management, of obesity and T2D.
Subject(s)
Diabetes Mellitus, Type 2 , Glycemic Control , Obesity , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/diet therapy , Humans , Obesity/metabolism , Glycemic Control/methods , Animals , Body Weight , Animal Proteins, Dietary/administration & dosage , Plant Proteins, Dietary/administration & dosage , Blood Glucose/metabolism , Energy Intake , Dietary Proteins/administration & dosageABSTRACT
Objective: The oxidative balance score (OBS) is a comprehensive concept that includes 20 oxidative stressors and can be used to assess individual pro-oxidant versus antioxidant exposure, and the aim of the present study was to investigate the association between OBS and the risk of diabetic kidney disease (DKD), low estimated glomerular filtration rate (low-eGFR) and albuminuria in patients with diabetes mellitus (DM). Methods: This cross-sectional study included nationally representative consecutive National Health and Nutrition Examination Survey DM patients aged 18 years and older from 2003-2018. The continuous variable OBS was converted into categorical variables by quartiles, and weighted multiple logistic regression analyses and restricted triple spline models were used to explore the relationships. We also performed subgroup analyses and interaction tests to verify the stability of the results. Results: A total of 5389 participants were included, representing 23.6 million non-institutionalized US residents. The results from both multivariate logistic regression analysis and restricted cubic spline models indicated that OBS and dietary OBS levels were negatively associated with the risk of DKD, low-eGFR, and albuminuria, without finding a significant correlation between lifestyle OBS and these clinical outcomes. Compared to the lowest OBS quartile group, the prevalence risk of DKD (OR = 0.61, 95% CI: 0.46-0.80), low-eGFR (OR = 0.46, 95% CI: 0.33-0.64) and albuminuria (OR = 0.68, 95% CI: 0.51-0.92) decreased by 39%, 54% and 32%, respectively, in the highest OBS quartile group. The results remained stable in subgroup analyses and no interaction between subgroups was found. Conclusion: Higher levels of OBS and dietary OBS were associated with a lower risk of DKD, low-eGFR, and albuminuria. These findings provided preliminary evidence for the importance of adhering to an antioxidant-rich diet and lifestyle among individuals with diabetes.
Subject(s)
Albuminuria , Diabetes Mellitus, Type 2 , Diabetic Nephropathies , Glomerular Filtration Rate , Oxidative Stress , Humans , Cross-Sectional Studies , Male , Female , Albuminuria/epidemiology , Diabetic Nephropathies/epidemiology , Diabetic Nephropathies/physiopathology , Diabetic Nephropathies/etiology , Middle Aged , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/physiopathology , Adult , Aged , Nutrition Surveys , Risk FactorsSubject(s)
Cholesterol , Liver X Receptors , Prediabetic State , Signal Transduction , Humans , Prediabetic State/metabolism , Liver X Receptors/metabolism , Liver X Receptors/genetics , Cholesterol/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Receptors, Cytoplasmic and Nuclear/genetics , Animals , Diabetes Mellitus/metabolism , Risk Factors , Diabetes Mellitus, Type 2/metabolism , MiceABSTRACT
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.
Subject(s)
Diabetes Mellitus, Type 2 , Insulin Resistance , Liver Cirrhosis , Humans , Liver Cirrhosis/metabolism , Insulin Resistance/physiology , Diabetes Mellitus, Type 2/metabolism , Animals , Signal Transduction , Insulin/metabolismABSTRACT
BACKGROUND: Type 2 diabetes mellitus (T2DM) is a common metabolic disease characterized by insulin resistance and insufficient relative insulin secretion, leading to elevated blood sugar and the development of diabetic complications. T2DM not only seriously affects people's health and quality of life, but also brings a heavy burden to society and economy. At present, the treatment of T2DM mainly relies on drug therapy, but these drugs often have problems such as side effects, resistance and high cost, and can not fully meet the needs and expectations of patients. Therefore, it is of great significance and value to find safe and effective natural medicines or functional foods to assist the treatment and prevention of T2DM. OBJECTIVE: Chinese jujube are a common fruit that contain abundant polyphenolic compounds, which exhibit multiple physiological activities, such as antioxidation, anti-inflammation, and blood glucose lowering. The objective of this study was to explore the impact of red date polyphenols on glycemic control and oxidative stress status in patients with type 2 diabetes mellitus (T2DM).
Subject(s)
Blood Glucose , Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 2 , Oxidative Stress , Polyphenols , Ziziphus , Oxidative Stress/drug effects , Polyphenols/pharmacology , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/blood , Animals , Ziziphus/chemistry , Blood Glucose/metabolism , Blood Glucose/drug effects , Blood Glucose/analysis , Male , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/metabolism , Rats , Antioxidants/pharmacology , Antioxidants/therapeutic use , Fruit/chemistry , Phytotherapy , Hypoglycemic Agents/therapeutic use , Hypoglycemic Agents/pharmacology , Rats, Sprague-Dawley , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Humans , East Asian PeopleABSTRACT
The Editors of Medical Science Monitor wish to inform you that the above manuscript has been retracted from publication due to concerns with the credibility and originality of the study, the manuscript content, and the Figure images. Reference: Weiwei Wei, Hao Tian, Xiandong Fu, Rongrong Yao, Dewang Su. Long Non-Coding RNA (lncRNA) SNHG5 Participates in Vertical Sleeve Gastrectomy for Type II Diabetes Mellitus by Regulating TGR5. Med Sci Monit, 2020; 26: e920628. DOI: 10.12659/MSM.920628.
Subject(s)
Diabetes Mellitus, Type 2 , Gastrectomy , RNA, Long Noncoding , Receptors, G-Protein-Coupled , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/surgery , Gastrectomy/methods , Humans , Receptors, G-Protein-Coupled/metabolism , Receptors, G-Protein-Coupled/genetics , Animals , MaleABSTRACT
Glucagon-like peptide 1 (GLP1), which is mainly processed and cleaved from proglucagon in enteroendocrine cells (EECs) of the intestinal tract, acts on the GLP1 receptor in pancreatic cells to stimulate insulin secretion and to inhibit glucagon secretion. However, GLP1 processing is not fully understood. Here, we show that reticulon 4B (Nogo-B), an endoplasmic reticulum (ER)-resident protein, interacts with the major proglucagon fragment of proglucagon to retain proglucagon on the ER, thereby inhibiting PCSK1-mediated cleavage of proglucagon in the Golgi. Intestinal Nogo-B knockout in male type 2 diabetes mellitus (T2DM) mice increases GLP1 and insulin levels and decreases glucagon levels, thereby alleviating pancreatic injury and insulin resistance. Finally, we identify aberrantly elevated Nogo-B expression and inhibited proglucagon cleavage in EECs from diabetic patients. Our study reveals the subcellular regulatory processes involving Nogo-B during GLP1 production and suggests intestinal Nogo-B as a potential therapeutic target for T2DM.
Subject(s)
Diabetes Mellitus, Type 2 , Endoplasmic Reticulum , Glucagon-Like Peptide 1 , Nogo Proteins , Proglucagon , Proprotein Convertase 1 , Animals , Humans , Male , Mice , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/genetics , Endoplasmic Reticulum/metabolism , Enteroendocrine Cells/metabolism , Glucagon-Like Peptide 1/metabolism , Golgi Apparatus/metabolism , HEK293 Cells , Insulin/metabolism , Insulin Resistance , Intestines/pathology , Mice, Inbred C57BL , Mice, Knockout , Nogo Proteins/metabolism , Nogo Proteins/genetics , Proglucagon/metabolism , Proglucagon/genetics , Proprotein Convertase 1/metabolism , Proprotein Convertase 1/genetics , Protein Binding , ProteolysisABSTRACT
Derived from enteroendocrine cells (EECs), glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are pivotal incretin hormones crucial for blood glucose regulation. Medications of GLP-1 analogs and GLP-1 receptor activators are extensively used in the treatment of type 2 diabetes (T2D) and obesity. However, there are currently no agents to stimulate endogenous incretin secretion. Here, we find the pivotal role of KCNH2 potassium channels in the regulation of incretin secretion. Co-localization of KCNH2 with incretin-secreting EECs in the intestinal epithelium of rodents highlights its significance. Gut epithelial cell-specific KCNH2 knockout in mice improves glucose tolerance and increases oral glucose-triggered GLP-1 and GIP secretion, particularly GIP. Furthermore, KCNH2-deficient primary intestinal epithelial cells exhibit heightened incretin, especially GIP secretion upon nutrient stimulation. Mechanistically, KCNH2 knockdown in EECs leads to reduced K+ currents, prolonged action potential duration, and elevated intracellular calcium levels. Finally, we found that dofetilide, a KCNH2-specific inhibitor, could promote incretin secretion in enteroendocrine STC-1 cells in vitro and in hyperglycemic mice in vivo. These findings elucidate, for the first time, the mechanism and application of KCNH2 in regulating incretin secretion by EECs. Given the therapeutic promise of GLP-1 and GIP in diabetes and obesity management, this study advances our understanding of incretin regulation, paving the way for potential incretin secretagogue therapies in the treatment of diabetes and obesity.
Subject(s)
Enteroendocrine Cells , Glucagon-Like Peptide 1 , Incretins , Animals , Mice , Incretins/pharmacology , Enteroendocrine Cells/metabolism , Enteroendocrine Cells/drug effects , Glucagon-Like Peptide 1/genetics , Glucagon-Like Peptide 1/metabolism , Humans , Gastric Inhibitory Polypeptide/genetics , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/pathology , Secretagogues/pharmacology , Mice, Knockout , ERG1 Potassium ChannelABSTRACT
Free Fatty Acids (FFAs) are vital for energy homeostasis and the pathogenesis of a variety of diseases, including diabetes. For the first time, we presumed and investigated the types and levels of FFAs and their links to Insulin Resistance (IR) and Oxidative Stress (OS) in T2DM. A case-control study was conducted on 60 individuals with diabetes, 60 prediabetics with IFG, and 60 control groups. A Gas Chromatography Flame Ionization Detector (GC-FID) was used to estimate FFAs, which were then classified based on length and saturation. Indeed, antioxidant parameters such as TAC, MDA levels, PON-1, SOD-3, and CAT activity were assessed. Higher levels of LCFFA, SFFA, USFFA, and total FFA were found in people with diabetes and prediabetes. These levels were also linked to higher levels of HOMA-IR, BMI, FBS, HbA1C, and MDA, but lower levels of antioxidants. Furthermore, adjusting the above FFAs with age, sex, and antihypertensive medication increased T2DM development. SCFFA and ω3/6 fatty acids had a negative relationship with HOMA-IR, FBS, and insulin and a positive relationship with TAC. Adjusted SCFFA reduces T2DM risk. According to our models, total FFA is utilized to diagnose diabetes (AUC = 83.98, cut-off > 919 µM) and SCFFA for prediabetes (AUC = 82.32, cut-off < 39.56 µM). Total FFA (≥ 776 µM), LCFFA (≥ 613 µM), SFFA (≥ 471 µM), and USFFA (≥ 398 µM) all increase the risk of T2DM by increasing OS, BMI, and HOMA-IR. On the other hand, SCFFAs (≥ 38.7 µM) reduce the risk of T2DM by reducing BMI, HOMA-IR, and OS. SCFFAs and total FFAs can be used for the diagnosis of prediabetes and diabetes, respectively.
Subject(s)
Diabetes Mellitus, Type 2 , Fatty Acids, Nonesterified , Insulin Resistance , Oxidative Stress , Humans , Fatty Acids, Nonesterified/blood , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/metabolism , Male , Case-Control Studies , Female , Middle Aged , Adult , Prediabetic State/blood , Prediabetic State/metabolism , Antioxidants/metabolism , AgedABSTRACT
Obesity is a chronic disease caused primarily by the imbalance between the amount of calories supplied to the body and energy expenditure. Not only does it deteriorate the quality of life, but most importantly it increases the risk of cardiovascular diseases and the development of type 2 diabetes mellitus, leading to reduced life expectancy. In this review, we would like to present the molecular pathomechanisms underlying obesity, which constitute the target points for the action of anti-obesity medications. These include the central nervous system, brain-gut-microbiome axis, gastrointestinal motility, and energy expenditure. A significant part of this article is dedicated to incretin-based drugs such as GLP-1 receptor agonists (e.g., liraglutide and semaglutide), as well as the brand new dual GLP-1 and GIP receptor agonist tirzepatide, all of which have become "block-buster" drugs due to their effectiveness in reducing body weight and beneficial effects on the patient's metabolic profile. Finally, this review article highlights newly designed molecules with the potential for future obesity management that are the subject of ongoing clinical trials.
Subject(s)
Anti-Obesity Agents , Obesity , Humans , Obesity/drug therapy , Obesity/metabolism , Anti-Obesity Agents/therapeutic use , Anti-Obesity Agents/pharmacology , Animals , Energy Metabolism/drug effects , Glucagon-Like Peptide-1 Receptor/agonists , Glucagon-Like Peptide-1 Receptor/metabolism , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Gastrointestinal Microbiome/drug effectsABSTRACT
Diabetic cardiomyopathy (DbCM) is a common complication in individuals with type 2 diabetes mellitus (T2DM), and its exact pathogenesis is still debated. It was hypothesized that chronic hyperglycemia and insulin resistance activate critical cellular pathways that are responsible for numerous functional and anatomical perturbations in the heart. Interstitial inflammation, oxidative stress, myocardial apoptosis, mitochondria dysfunction, defective cardiac metabolism, cardiac remodeling, hypertrophy and fibrosis with consequent impaired contractility are the most common mechanisms implicated. Epigenetic changes also have an emerging role in the regulation of these crucial pathways. The aim of this review was to highlight the increasing knowledge on the molecular mechanisms of DbCM and the new therapies targeting specific pathways.