Novel hypothalamic pathways for metabolic effects of spexin.

One of the main underlying etiologies of type 2 diabetes (T2DM) is insulin resistance, which is most frequently caused by obesity. Notably, the deregulation of adipokine secretion from visceral adiposity has been identified as a crucial characteristic of type 2 diabetes and obesity. Spexin is an adipokine that is released by many different tissues, including white adipocytes and the glandular stomach, and is negatively connected with the state of energy storage. This peptide acts through GALR2/3 receptors to control a wide range of metabolic processes, including inflammation, browning, lipolysis, energy expenditure, and eating behavior. Specifically, spexin can enter the hypothalamus and regulate the hypothalamic melanocortin system, which in turn balances energy expenditure and food intake. This review examines recent advances and the underlying mechanisms of spexin in obesity and T2DM. In particular, we address a range of topics from basic research to clinical findings, such as an analysis of the possible function of spexin in the hypothalamic melanocortin response, which involves reducing energy intake and increasing energy expenditure while also enhancing insulin sensitivity and glucose tolerance. Gaining more insight into the mechanisms that underlie the spexin system's control over energy metabolism and homeostasis may facilitate the development of innovative treatment approaches that focus on combating obesity and diabetes.

Effects of IL-6R Expression on IL-6/STAT3/HIF-1α Signaling Pathway in a Mouse Model of Parkinson's Disease with Type 2 Diabetes Co-Morbidity.

BACKGROUND: More and more evidence has shown the process of Parkinson's disease (PD). Probably, inflammation exerts a crucial role between them. Therefore, the aim of this study was to analyze the impact of interleukin-6 receptor (IL-6R) expression on the IL-6/signal transducer and activator of transcription 3 (STAT3)/hypoxia-inducible factor-1α (HIF-1α) inflammatory signaling pathway within a mouse model of PD with type 2 diabetes mellitus (T2DM) as co-morbidity. METHODS: We chose healthy wild-type C57BL/6J male mice at the age of 10 weeks to prepare a mouse model of PD with T2DM co-morbidity. Adeno-associated virus (AAV) overexpressing IL-6R or AAV IL-6R-shRNA genes were injected into the substantia nigra (SN) of the mice. The behavioral indices of the pole test were used for examining the motor function of the mice. Using immunofluorescence analysis, the impacts of IL-6R on the level of tyrosine hydroxylase (TH) and anti-ionized calcium-binding adaptor molecule 1 (IBA-1) on dopaminergic neurons and microglia were examined. Additionally, enzyme-linked immunosorbent assay (ELISA) was adopted for determining the expressions of HIF-1α and inflammatory cytokines like tumor necrosis factor-α (TNF-α), IL-1ß, IL-6, and IL-4 in the serum. In this study, the protein expression levels of TH, α-Synuclein (α-Syn), IBA-1, IL-6, IL-6R, phosphorylated and total signal transducer and activator of transcription 3 (p-STAT3 (Tyr705) and STAT3) and HIF-1α in the SN were tested via western blotting. To ascertain the mRNA expressions of TNF-α, IL-1ß, IL-6, IL-4, and HIF-1α, we used quantitative Real-Time Polymerase Chain Reaction (RT-qPCR). RESULTS: IL-6R-shRNA treatment could markedly shorten the total time of PD in the T2DM co-morbidity mouse model based on the pole test results, reverse the decrease in TH-positive neurons stimulated by 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP), and lower the activation of microglia (all p < 0.05). Further, IL-6R-shRNA treatment hindered the expression of IL-6, p-STAT3 (Tyr705), and HIF-1α in the SN, lowered the levels of TNF-α, IL-1ß, IL-6, IL-4, and HIF-1α in the serum, and mRNA expressions of TNF-α, IL-1ß, IL-6, and HIF-1α in the SN (all p < 0.05). In contrast, IL-6R overexpression reduced TH levels, upregulated the level of IBA-1, IL-6, p-STAT3 (Tyr705), and HIF-1α, increased the level of IL-1ß, TNF-α, IL-6, IL-4, and HIF-1α (all p < 0.05) in the serum and SN in the PD mouse model with T2DM as a co-morbidity. CONCLUSIONS: PD progression with T2DM as a co-morbidity can be boosted by AAV IL-6R-overexpression through upregulation of the IL-6/STAT3/HIF-1α axis. Conversely, AAV IL-6R-shRNA treatment suppressed the IL-6/STAT3/HIF-1α pathway and alleviated neuroinflammation, thus weakening the development of PD with T2DM as a co-morbidity.

Meta-analysis of the clinical efficacy of liraglutide in treating type 2 diabetes mellitus complicated with non-alcoholic fatty liver disease.

This study aimed to systematically evaluate the efficacy of liraglutide in treating type 2 diabetes mellitus (T2DM) complicated with non-alcoholic fatty liver disease (NAFLD) by comparing liraglutide with placebo or other drugs (mainly insulin). The PubMed, Web of Science, and National Library of Medicine databases were systematically searched from their inception until December 1, 2023. A meta-analysis was performed using Stata 15.1 software. A total of 12 studies with 13 outcome measures were included. The meta-analysis results revealed that liraglutide significantly reduced body mass index (mean difference [MD] = -1.06, 95%CI: -1.41, -0.70, p < 0.001), triglycerides (MD = -0.35, 95%CI: -0.61, -0.09, p = 0.0009), visceral adipose tissue (MD = -21.06, 95%CI: -34.58, -7.55, p = 0.002), and subcutaneous adipose tissue (MD = -20.53, 95%CI: -29.15, -11.90, p < 0.001) levels in patients with T2DM and NAFLD. Of the 11 studies, 2 reported the occurrence of adverse reactions, which were primarily gastrointestinal. Compared with placebo and other drugs (e.g., insulin), liraglutide may improve glucose metabolism, lipid and liver function parameters, and visceral and subcutaneous fat in patients with T2DM and NAFLD, thus constituting an effective treatment for these patients.

Adipose-Muscle crosstalk in age-related metabolic disorders: The emerging roles of adipo-myokines.

Obesity and type 2 diabetes account for a considerable proportion of the global burden of age-related metabolic diseases. In age-related metabolic diseases, tissue crosstalk and metabolic regulation have been primarily linked to endocrine processes. Skeletal muscle and adipose tissue are endocrine organs that release myokines and adipokines into the bloodstream, respectively. These cytokines regulate metabolic responses in a variety of tissues, including skeletal muscle and adipose tissue. However, the intricate mechanisms underlying adipose-muscle crosstalk in age-related metabolic diseases are not fully understood. Recent exciting evidence suggests that myokines act to control adipose tissue functions, including lipolysis, browning, and inflammation, whereas adipokines mediate the beneficial actions of adipose tissue in the muscle, such as glucose uptake and metabolism. In this review, we assess the mechanisms of adipose-muscle crosstalk in age-related disorders and propose that the adipokines adiponectin and spexin, as well as the myokines irisin and interleukin-6 (IL-6), are crucial for maintaining the body's metabolic balance in age-related metabolic disorders. In addition, these changes of adipose-muscle crosstalk in response to exercise or dietary flavonoid consumption are part of the mechanisms of both functions in the remission of age-related metabolic disorders. A better understanding of the intricate relationships between adipose tissue and skeletal muscle could lead to more potent therapeutic approaches to prolong life and prevent age-related metabolic diseases.

Cardioprotective effects of neuropeptide galanin: Focusing on its roles against diabetic heart.

Following an unprecedented rise in the number of the aged, the incidence of age-related diseases, such as diabetes and cardiovascular disease, is consequently increasing in the world. Type 2 diabetes mellitus (T2DM) is associated with excess cardiovascular morbidity and mortality. The diabetic heart is characterized by increased cardiomyocyte stiffness and fibrotic changes. Despite many factors resulting in cardiomyocyte injury and dysfunction in diabetes, insulin resistance is still a critical etiology of diabetic cardiomyopathy. Preclinical and clinical studies have revealed an intriguing role for galanin in the pathogenesis of insulin resistance and diabetic heart disease. A significant change in plasma galanin levels occurred in patients suffering from type 2 diabetes or cardiomyocyte injury. In turn, galanin may also distinctly mitigate hyperglycemia and insulin resistance in diabetes as well as increase glucose metabolism and mitochondrial biogenesis in cardiac muscle. Here, we critically review current data about the multivariate relationship among galanin, insulin resistance, and cardiac muscle to comprehensively evaluate the protective role of galanin and its receptors for the diabetic heart and to determine whether galanin receptor 2 agonists potentially represent a feasible way to treat diabetic cardiomyopathy in the future.

Emerging Protective Actions of PGC-1α in Diabetic Nephropathy.

Renal impairment is affected by various mechanisms of oxidative stress, mitochondrial dysfunction, and basement membrane thickening, which are the major causes of renal dysfunction in diabetes. Of note, hyperglycemia-induced mitochondrial dysfunction has been identified as a common cause of diabetic nephropathy and renal impairment, and the decrease in PGC-1α expression brought on by hyperglycemia plays an immensurable role in both the reduction of mitochondrial biogenesis and the rise in oxidative stress. Reduced PGC-1α expression levels may occur with rising SGLT2-dependent increase of cytoplasmic sodium and protons in the renal cells of diabetes, even if the precise mechanism of hyperglycemia-induced disruption of PGC-1α expression has not been identified. Additionally, it has been observed that SGLT2 inhibitors enhance PGC-1α expression and activity and decrease cytoplasmic sodium and protons in many kidney cells, which may be helpful in reducing renal impairment brought on by diabetes. This review summarizes our and other recent studies on the function of PGC-1α in diabetic nephropathy, provides another potential mediator of the lower PGC-1α expression levels brought on by hyperglycemia in diabetics, and identifies a new pathogenesis of diabetes-related renal impairment. It also explains the mechanism underlying the protective effects of SGLT2 inhibitors on diabetic nephropathy. Therefore, it should be taken into account that SGLT2 inhibitors are an effective therapeutic strategy for reducing renal dysfunction caused by diabetes.

Effect of Peptide Drug Liraglutide Nano-Formulation Combined with Sodium-Glucose Cotransporter-2 Inhibitor on Blood Lipids in Patients with Type 2 Diabetes.

With the aging of our population and the increase in the number of obese people, diabetes has become a common disease. At present, drug treatment is mainly used for diabetes. Dyslipidemia is the main cause of diabetes. The regulation of blood lipids in diabetic patients through drugs is the key to treating diabetes. The purpose of this article is to further explore the specific effect and mechanism of peptide drug liraglutide nano-formulation combined with sodium-glucose co-transporter-2(SGCT-2) inhibitor on blood lipids in patients with type 2 diabetes. This article uses 30 people included in our hospital in 2019 2 patients with type 2 diabetes are divided into the group of peptide drug liraglutide nano preparations, the group of SGCT-2 inhibitors and the peptide drug liraglutide nano preparations combined with SGCT-2. In the inhibitor combination medication group, patients were given drug intervention according to the group name with the consent of the patients. After three days, the serum cholesterol, triglyceride, lipoprotein and lipid metabolism levels of all patients were tested. The results showed that under the intervention of peptide drug liraglutide nanoparticles combined with SGCT-2 inhibitor, the cholesterol level of patients with type 2 diabetes decreased from (368.2 ± 8.3) mmol / L to (1978.4 ± 4.7) mmol/L, triglyceride level decreased from (653.7 ± 12.5) mg/dL to (426.8 ± 9.6) mg/dl, and lipid metabolism level increased by 25.6%. Therefore, it can be seen that the peptide drug liraglutide nano preparation combined with SGCT-2 inhibitor has a certain therapeutic effect on type 2 diabetes.

Serum ErbB2 concentration positively correlated to the glycemic variations in newly diagnosed Type 2 diabetic patients.

Evidences indicate that elevated levels of circulating ErbB2 are closely associated with increased incidence of diabetes. However, the relationship between ErbB2 concentration and glycemic variations (GV) in type 2 diabetic (T2D) patients remains elucidated. The aim of this study was to assess whether there is an association between serum ErbB2 concentration and GV in newly diagnosed T2D patients. This was a three-center, and observational study. Between April 2019 and July 2019, a total of 106 newly diagnosed T2D patients were recruited. All recruited subjects were admitted as inpatients and received anti-diabetes agents free during the study period. At baseline, fasting serum was collected for ErbB2 measurement and all recruited patients were subjected a prospective CGM for at least 3 days. The primary endpoint was the relationships between ErbB2 concentrations and GV in T2D patients. Data of a total of 95 subjects who met the inclusion criteria were analyzed at the endpoint. Subjects were divided into quartiles according to their serum ErbB2 concentrations. We observed that subjects with an elevated level of ErbB2 had a higher value of GV in terms of mean amplitude of glucose excursion (MAGE), standard deviation of mean glucose (SDMG), and the coefficient of variation (CV%) than those with lower levels (all P < 0.05). Multiple linear regression analyzes after adjusting for confounder factors indicate that serum ErbB2 levels were significantly positively correlated with the MAGE (ß = 0.664, t = 7.218, P < 0.01), SD (ß = 0.469, t = 5.125, P < 0.01) and CV% (ß = 0.337, t = 4.442, P < 0.01), respectively. Our data indicated that diabetic patients with higher ErbB2 concentrations may have large GV, which is an independent risk factor for microvascular and macrovascular complications.

Time-restricted feeding prevents metabolic diseases through the regulation of galanin/GALR1 expression in the hypothalamus of mice.

PURPOSE: Time-restricted feeding (TRF) reverses obesity and insulin resistance, yet the central mechanisms underlying its beneficial effects are not fully understood. Recent studies suggest a critical role of hypothalamic galanin and its receptors in the regulation of energy balance. It is yet unclear whether TRF could regulate the expression of galanin and its receptors in the hypothalamus of mice fed a high-fat diet. METHODS: To test this effect, we subjected mice to either ad lib or TRF of a high-fat diet for 8 h per day. After 4 weeks, galanin and many neuropeptides associated with the function of metabolism were examined. RESULTS: The present findings showed that mice under TRF consume equivalent calories from a high-fat diet as those with ad lib access, yet are protected against obesity and have improved glucose metabolism. Plasma galanin, orexin A, irisin and adropin levels were significantly reversed by TRF regimen. Besides, TRF regimen reversed the progression of metabolic disorders in mice by increasing GLUT4 and PGC-1α expression in skeletal muscles. Moreover, the levels of galanin and GALR1 expression were severely diminished in the hypothalamus of the TRF mice, whereas GALR2 was highly expressed. CONCLUSIONS: TRF diminished galanin and GALR1 expression, and increased GALR2 expression in the hypothalamus of mice fed a high-fat diet. The current studies provide additional evidence that TRF is effective in improving HFD-induced hyperglycemia and insulin resistance in mice, and this effect could be associated with TRF-induced changes of the galanin systems in the hypothalamus. LEVEL OF EVIDENCE: No level of evidence, animal studies.

Adipose tissue spexin in physical exercise and age-associated diseases.

It is known that a strong association exists between a suboptimal lifestyle (physical inactivity and sedentary behavior and/or high calorie diet) and increased propensity of developing age-associated diseases, such as obesity and T2DM. Physical exercise can alleviate obesity-induced insulin resistance and T2DM, however, the precise mechanism for this outcome is not fully understood. The endocrine disorder of adipose tissue in obesity plays a critical role in the development of insulin resistance. In this regard, spexin has been recently described as an adipokine that plays an important role in the pathophysiology of obesity-induced insulin resistance and T2DM. In obese states, expression of adipose tissue spexin is reduced, inducing the adipose tissue and skeletal muscle more susceptible to insulin resistance. Emerging evidences point out that exercise can increase spexin expression. In return, spexin could exert the exercise-protective roles to ameliorate insulin resistance, suggesting that spexin is a potential mediator for exercise to ameliorate obesity-induced insulin resistance and T2DM, namely, the beneficial effect of exercise on insulin sensitivity is at least partly mediated by spexin. This review summarizes our and others' recent studies regarding the effects of obesity on adipose tissue spexin induction, along with the potential effect of exercise on this response in obese context, and provides a new insight into the multivariate relationship among exercise, spexin and T2DM. It should be therefore taken into account that a combination of spexin and exercise training is an effective therapeutic strategy for age-associated diseases.

Emerging roles of kisspeptin/galanin in age-related metabolic disease.

Age is a major risk factor for developing metabolic diseases such as obesity and diabetes. There is an unprecedented rise in obesity and type 2 diabetes in recent decades. A convincing majority of brain-gut peptides are associated with a higher risk to develop metabolic disorders, and may contribute to the pathophysiology of age-related metabolic diseases. Accumulating basic studies revealed an intriguing role of kisspeptin and galanin involved in the amelioration of insulin resistance in different ways. In patients suffered from obesity and diabetes a significant, sex-related changes in the plasma kisspeptin and galanin levels occurred. Kisspeptin is anorexigenic to prevent obesity, its level is negatively correlative with obesity and insulin resistance. While galanin is appetitive to stimulate food intake and body weight, its level is positively correlative with obesity, HOMA-IR and glucose/triglyceride concentration. In turn, kisspeptin and galanin also distinctly increase glucose uptake and utilization as well as energy expenditure. This article reviews recent evidence dealing with the role of kisspeptin and galanin in the pathophysiology of age-related metabolic diseases. It should be therefore taken into account that the targeted modulation of those peptidergic signaling may be potentially helpful in the future treatment of age-related metabolic diseases.

Low levels of spexin and adiponectin may predict insulin resistance in patients with non-alcoholic fatty liver.

Adipose tissue is endocrine organ that responds by secreting numerous hormones that regulate metabolism in skeletal muscle and the liver. The aim of this study was to compare the levels of spexin and adiponectin in patients with non-alcoholic fatty liver and evaluate the relationship between circulating adipocytokines and insulin resistance. Two groups of subjects were evaluated: 41 non-alcoholic fatty liver subjects (age 35.17 â€‹± â€‹12.29 year, BMI 30.97 â€‹± â€‹2.75 â€‹kg/m2) and 38 normal controls (age 38.47 â€‹± â€‹11.63 year, BMI 22.83 â€‹± â€‹3.00 â€‹kg/m2). Plasma concentrations of spexin and adiponectin were determined using immunosorbent assay kits. Insulin resistance was assessed using the homeostasis model assessment (HOMA-IR) formula derived from fasting insulin and glucose levels. Compared to normal controls, plasma concentrations of spexin and adiponectin were significantly lower in patients with non-alcoholic fatty liver (P â€‹< â€‹0.001). Spexin did not correlate with BMI but did significantly correlate with HOMA-IR (r â€‹= â€‹-0.368; P â€‹= â€‹0.018) and adiponectin (r â€‹= â€‹0.378; P â€‹= â€‹0.043), and this correlation remained significant after adjustment for gender and BMI. In this small group of patients with non-alcoholic fatty liver we demonstrated that insulin resistance correlated strongly with spexin and adiponectin levels.

Effect of sodium-glucose co-transporter-2 inhibitors on the levels of serum asprosin in patients with newly diagnosed type 2 diabetes mellitus.

BACKGROUND: Asprosin, a novel adipokine that raises glucose levels and stimulates appetite, has been proved to be pathologically increased in populations predisposed to type 2 diabetes mellitus (T2DM), obesity, and cardiovascular diseases. The mechanisms of sodium-glucose co-transporter-2 (SGLT2) inhibitors for hypoglycemic effect and cardiovascular protection have not been fully clarified. Therefore, we conducted this study to assess change in the levels of serum asprosin after treatment with SGLT2 inhibitors in patients with newly diagnosed T2DM. METHODS: This study was a randomized, double-blind, placebo-controlled trial. A total of 29 participants with newly diagnosed T2DM with body mass index (BMI) ≥ 23.0 kg/m2 and haemoglobin A1c (HbA1c) levels of 58-85 mmol/mol (7.5-10%) were randomized to SGLT2 inhibitors dapagliflozin 10 mg/d (n = 19) or placebo (n = 10) treatment for 24 weeks. We analyzed asprosin concentrations by an enzyme-linked immunosorbent assay. Besides, body weight, BMI, HbA1c, fasting plasma glucose (FPG), and lipid levels were measured at baseline and 24 weeks. RESULTS: At 24 weeks, participants with SGLT2 inhibitors treatment exhibited lower levels of serum asprosin (22.87 vs 45.06 ng/ml in the placebo group; P < 0.001) after adjusting for baseline values. The levels of body weight, BMI, HbA1c, FPG, and triglyceride (TG) were decreased, while high density lipoprotein-cholesterol (HDL-C) was increased after SGLT2 inhibitors dapagliflozin treatment compared with placebo (P < 0.05 for all). Low density lipoprotein-cholesterol (LDL-C) and total cholesterol (TC) levels were unchanged in the SGLT2 inhibitors group and placebo group. No statistical correlation was found between the levels of serum asprosin and body weight, BMI, HbA1c, FPG, and lipid levels during the SGLT2 inhibitor dapagliflozin treatment. CONCLUSIONS: These findings indicated that SGLT2 inhibitors can lower serum asprosin levels and improve glucolipid and weight in patients with newly diagnosed T2DM, which may benefit the cardiovascular system. Trial registration CTR20131268; Registered 20 March 2014 CTR20150102; Registered 03 March 2015. http://www.chinadrugtrials.org.cn/clinicaltrials.searchlistdetail.dhtml .

Time-restricted feeding attenuates gluconeogenic activity through inhibition of PGC-1α expression and activity.

BACKGROUND: Time-restricted feeding (TRF), a key component of intermittent fasting regimens, has gained considerable attention in recent years due to reversing obesity and insulin resistance. To the best of our knowledge, here, we reported for the first time the underlying mechanistic therapeutic efficacy of TRF against hepatic gluconeogenic activity in obese mice. METHODS: The obese mice were subjected to either ad lib or TRF of a high fat diet for 8 h per day for 4 weeks. Western blotting, qRT-PCR, and plasma biochemical analyses were applied. RESULTS: The present findings showed that TRF regimen reduced food intake, and reversed high fat diet-induced glucose intolerance, hyperglycemia and insulin resistance in mice of high fat diet-induced obesity. Mechanistically, we confirmed that TRF regimen protected against hyperglycemia and ameliorated hepatic gluconeogenic activity through inhibition of p38 MAPK/SIRT1/PGC-1α signal pathway. CONCLUSION: Our findings suggest that TRF regimen might be a potential novel nonpharmacological strategy against obesity/diabetes-induced hyperglycemia and insulin resistance.

A promising biomarker of elevated galanin level in hypothalamus for osteoporosis risk in type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) and osteoporosis are two major healthcare problems worldwide. T2DM is considered to be a risk factor for osteoporosis. Interestingly, several epidemiological studies suggest that bone abnormalities associated with diabetes may differ, at least in part, from those associated with senile or post-menopausal osteoporosis. The growing prevalence that patients with T2DM simultaneously suffer from osteoporosis, puts forward the importance to discuss the relationship between both diseases, as well as to investigate correlative agents to treat them. Emerging evidences demonstrate that neuropeptide galanin is involved in the pathogenesis of T2DM and osteoporosis. Galanin via activation of central GALR2 increases insulin sensitivity as well as bone density and mass in animal models. The disorder of galanin function plays major role in development of both diseases. Importantly, galanin signaling is indispensable for ΔFosB, an AP1 antagonist, to play the bone mass-accruing effects in the ventral hypothalamic neurons of diabetic models. This review summarizes our and other recent studies to provide a new insight into the multivariate relationship among galanin, T2DM and osteoporosis, highlighting the beneficial effect of galanin on the comorbid state of both diseases. These may help us better understanding the pathogenesis of osteoporosis and T2DM and provide useful clues for further inquiry if elevated galanin level may be taken as a biomarker for both conjoint diseases, and GALR2 agonist may be taken as a novel therapeutic strategy to treat both diseases concurrently.