Combination therapy for kidney disease in people with diabetes mellitus.

Diabetic kidney disease (DKD), defined as co-existing diabetes and chronic kidney disease in the absence of other clear causes of kidney injury, occurs in approximately 20-40% of patients with diabetes mellitus. As the global prevalence of diabetes has increased, DKD has become highly prevalent and a leading cause of kidney failure, accelerated cardiovascular disease, premature mortality and global health care expenditure. Multiple pathophysiological mechanisms contribute to DKD, and single lifestyle or pharmacological interventions have shown limited efficacy at preserving kidney function. For nearly two decades, renin-angiotensin system inhibitors were the only available kidney-protective drugs. However, several new drug classes, including sodium glucose cotransporter-2 inhibitors, a non-steroidal mineralocorticoid antagonist and a selective endothelin receptor antagonist, have now been demonstrated to improve kidney outcomes in people with type 2 diabetes mellitus. In addition, emerging preclinical and clinical evidence of the kidney-protective effects of glucagon-like-peptide-1 receptor agonists has led to the prospective testing of these agents for DKD. Research and clinical efforts are geared towards using therapies with potentially complementary efficacy in combination to safely halt kidney disease progression. As more kidney-protective drugs become available, the outlook for people living with DKD should improve in the next few decades.

Screening for Inflammatory Markers Identifies IL-18Rα as a Potential Link between Exenatide and Its Anti-Inflammatory Effect: New Results from the Combat-JUDO Randomized Controlled Trial.

INTRODUCTION: Obesity is associated with chronic inflammation. Chronic inflammation has also been linked to insulin resistance and type 2 diabetes, metabolic associated fatty liver disease, and cardiovascular disease. Glucagon-like peptide-1 (GLP-1) receptor analogs (GLP-1RA) are clinically used to treat obesity, with known anti-inflammatory properties. How the GLP-1RA exenatide effects inflammation in adolescents with obesity is not fully investigated. METHODS: Forty-four patients were randomized to receive weekly subcutaneous injections with either 2 mg exenatide or placebo for 6 months. Plasma samples were collected at baseline and at the end of the study, and 92 inflammatory proteins were measured. RESULTS: Following treatment with exenatide, 15 out of the 92 proteins were decreased, and one was increased. However, after adjustment for multiple testing, only IL-18Rα was significantly lowered following treatment. CONCLUSIONS: Weekly injections with 2 mg of exenatide lowers circulating IL-18Rα in adolescents with obesity, which may be a potential link between exenatide and its anti-inflammatory effect in vivo. This contributes to exenatide's pharmaceutical potential as a treatment for obesity beyond weight control and glucose tolerance, and should be further studied mechanistically.

Mollugin activates GLP-1R to improve cognitive dysfunction in type 2 diabetic mice.

AIMS: The incidence of diabetic cognitive dysfunction is increasing year by year, and it has gradually become a research hot spot. Studies have shown that glucagon-like peptide-1 receptor (GLP-1R) agonists can improve cognitive dysfunction in diabetic patients. This study focuses on whether small molecule GLP-1R agonists from traditional Chinese medicine (TCM) can improve the diabetic cognitive dysfunction. MATERIALS AND METHODS: The small molecules from TCM were screened by cell membrane chromatography (CMC) with GLP-1R-HEK293 cell membrane column. MTT assay, flow cytometry, immunofluorescence cytochemistry and other methods were used to determine the effects of mollugin on the apoptosis rate and reactive oxygen species (ROS) level of high glucose (HG)/hydrogen peroxide (H2O2) induced PC12 cells. Real-Time PCR was used to detect mRNA expression in mouse cerebral cortex. Water maze test was further used to confirm the effect of mollugin on cognitive dysfunction in T2DM mice. KEY FINDINGS: Mollugin bound to GLP-1R, promoted Ca2+ influx, increased insulin secretion and cAMP content in ß-TC-6 cells. Mollugin enhanced the cell viability, ameliorated apoptosis, reduced intracellular ROS levels in HG/H2O2-injured PC12 cells. Mollugin reduced the T2DM mice's escape latency, improved neuronal cell damage, decreased the expression of Pik3ca, Akt1 and Mapk1 mRNA in the cerebral cortex tissue. SIGNIFICANCE: The results suggest that mollugin could improve cognitive dysfunction in T2DM mice through activating GLP-1R/cAMP/PKA signal pathway.

Schisandrin B, a potential GLP-1R agonist, exerts anti-diabetic effects by stimulating insulin secretion.

Diabetes mellitus is a metabolic disease that is characterized by elevated blood sugar. Although glucagon-like peptide-1 receptor agonists (GLP-1RA) lower blood glucose in a glucose-dependent manner, most of them are macromolecule polypeptides. Macromolecular peptides are relatively expensive and inconvenient compared with small molecules. Therefore, this study sought to identify the small molecules binding to GLP-1R via cell membrane chromatography (CMC), confirm their agonistic activity, and further study its beneficial effects in a mouse model of type 2 diabetes mellitus (T2DM) induced by a combination of high-fat diet and streptozotocin. We used CMC, calcium imaging and molecular docking techniques to screen and identify the potential small molecule Schisandrin B (Sch B), which exhibits a strong binding effect to GLP-1R, from the small molecule library of traditional Chinese medicine. Through in-vitro experiments, we found that Sch B stimulated insulin secretion in ß-TC-6 cells, while GLP-1R antagonist Exendin9-39, adenylate cyclase inhibitor SQ22536, and protein kinase A (PKA) inhibitor H89 could significantly inhibit the insulin secretion induced by Sch B. In vivo, Sch B significantly improved fasting blood glucose levels, intraperitoneal glucose tolerance test damage, and the status of pancreatic tissue damage, and reduced serum insulin levels, total cholesterol, triglyceride and low density lipoprotein in T2DM mice. These results indicate that Sch B alleviates T2DM by promoting insulin release through the GLP-1R/cAMP/PKA signaling pathway, suggesting that Sch B may be a potential GLP-1RA, which is expected to provide a new therapeutic strategy for the prevention and treatment of T2DM.

Proglucagon signalling in the rat Dorsomedial Hypothalamus - Physiology and high-fat diet-mediated alterations.

A relatively new pharmacological target in obesity treatment has been the preproglucagon (PPG) signalling, predominantly with glucagon-like peptide (GLP) 1 receptor agonists. As far as the PPG role within the digestive system is well recognised, its actions in the brain remain understudied. Here, we investigated PPG signalling in the Dorsomedial Hypothalamus (DMH), a structure involved in feeding regulation and metabolism, using in situ hybridisation, electrophysiology, and immunohistochemistry. Our experiments were performed on animals fed both control, and high-fat diet (HFD), uncovering HFD-mediated alterations. First, sensitivity to exendin-4 (Exn4, a GLP1R agonist) was shown to increase under HFD, with a higher number of responsive neurons. The amplitude of the response to both Exn4 and oxyntomodulin (Oxm) was also altered, diminishing its relationship with the cells' spontaneous firing rate. Not only neuronal sensitivity, but also GLP1 presence, and therefore possibly release, was influenced by HFD. Immunofluorescent labelling of the GLP1 showed changes in its density depending on the metabolic state (fasted/fed), but this effect was eliminated by HFD feeding. Interestingly, these dietary differences were absent after a period of restricted feeding, allowing for an anticipation of the alternating metabolic states, which suggests possible prevention of such outcome.

Impact of GLP-1 receptor agonist versus omega-3 fatty acids supplement on obesity-induced alterations of mitochondrial respiration.

Objective: To compare administration of the glucagon-like peptide-1 (GLP-1) analogue, exenatide, versus dietary supplementation with the omega-3 fatty acid-rich Calanus oil on obesity-induced alterations in mitochondrial respiration. Methods: Six-week-old female C57BL/6JOlaHSD mice were given high fat diet (HFD, 45% energy from fat) for 12 weeks to induce obesity. Thereafter, they were divided in three groups where one received exenatide (10 µg/kg/day) via subcutaneously implanted mini-osmotic pumps, a second group received 2% Calanus oil as dietary supplement, while the third group received HFD without any treatment. Animals were sacrificed after 8 weeks of treatment and tissues (skeletal muscle, liver, and white adipose tissue) were collected for measurement of mitochondrial respiratory activity by high-resolution respirometry, using an Oroboros Oxygraph-2k (Oroboros instruments, Innsbruck, Austria). Results: It was found that high-fat feeding led to a marked reduction of mitochondrial respiration in adipose tissue during all three states investigated - LEAK, OXPHOS and ETS. This response was to some extent attenuated by exenatide treatment, but not with Calanus oil treatment. High-fat feeding had no major effect on hepatic mitochondrial respiration, but exenatide treatment resulted in a significant increase in the various respiratory states in liver. Mitochondrial respiration in skeletal muscle was not significantly influenced by high-fat diet or any of the treatments. The precise evaluation of mitochondrial respiration considering absolute oxygen flux and ratios to assess flux control efficiency avoided misinterpretation of the results. Conclusions: Exenatide increased hepatic mitochondrial respiration in high-fat fed mice, but no clear beneficial effect was observed in skeletal muscle or fat tissue. Calanus oil did not negatively affect respiratory activity in these tissues, which maintains its potential as a dietary supplement, due to its previously reported benefits on cardiac function.

Comparative efficacy of glucagon-like peptide 1 (GLP-1) receptor agonists, pioglitazone and vitamin E for liver histology among patients with nonalcoholic fatty liver disease: systematic review and pilot network meta-analysis of randomized controlled trials.

INTRODUCTION: There is no conclusive evidence comparing the efficacy of glucagon-like peptide 1 (GLP-1) receptor agonists to the other guidelines recommended pharmacotherapy for nonalcoholic fatty liver disease (NAFLD). Therefore, we aim to compare the effects of GLP-1 receptor agonists, pioglitazone and vitamin E in patients with NAFLD. METHODS: We searched PubMed, Embase, Web of Science and Cochrane Library up to 11 April 2022. Randomized clinical trials (RCTs) comparing GLP-1 receptor agonists, pioglitazone and vitamin E against placebo or other active controls in patients with NAFLD were included. RESULTS: Nine RCTs including 1482 patients proved eligible. GLP-1 receptor agonists ranked first in steatosis, ballooning necrosis, γ-glutamyl transferase, body weight, body mass index, and triglycerides. Administration of GLP-1 receptor agonists, as compared with placebo, was associated with improvement in liver histology [steatosis (OR = 4.11, 95% CI: 2.83, 5.96), ballooning necrosis (OR = 3.07, 95% CI: 2.14, 4.41), lobular inflammation (OR = 1.86, 95% CI: 1.29, 2.68), fibrosis (OR = 1.52, 95% CI: 1.06, 2.20)]. CONCLUSIONS: GLP-1 receptor agonists were as effective as pioglitazone and vitamin E for liver histology among patients with NAFLD. GLP-1 receptor agonists might be considered as an alternative or complementary treatment in the future clinical practice. [Figure: see text].

Comparison of Sodium-Glucose Cotransporter-2 Inhibitor and Glucagon-Like Peptide-1 Receptor Agonist Prescribing in Patients With Diabetes Mellitus With and Without Cardiovascular Disease.

Sodium-glucose cotransporter-2 inhibitors (SGLT2is) and glucagon-like peptide-1 receptor agonists (GLP1-RAs) reduce cardiovascular events and mortality in patients with type 2 diabetes mellitus (T2DM). We sought to describe trends in prescribing for SGLT2is and GLP1-RAs in diverse care settings, including (1) the outpatient clinics of a midwestern integrated health system and (2) small- and medium-sized community-based primary care practices and health centers in 3 midwestern states. We included adults with T2DM and ≥1 outpatient clinic visit. The outcomes of interest were annual active prescription rates for SGLT2is and GLP1-RAs (separately). In the integrated health system, 22,672 patients met the case definition of T2DM. From 2013 to 2019, the overall prescription rate for SGLT2is increased from 1% to 15% (absolute difference [AD] 14%, 95% confidence interval [CI] 13% to 15%, p <0.01). The GLP1-RA prescription rate was stable at 10% (AD 0%, 95% CI -1% to 1%, p = 0.9). In community-based primary care practices, 43,340 patients met the case definition of T2DM. From 2013 to 2017, the SGLT2i prescription rate increased from 3% to 7% (AD 4%, 95% CI 3% to 6%, p <0.01), whereas the GLP1-RA prescription rate was stable at 2% to 3% (AD 1%, 95% CI -1 to 1%, p = 0.40). In a fully adjusted regression model, non-Hispanic Black patients had lower odds of SGLT2i or GLP1-RA prescription (odds ratio 0.56, 95% CI 0.34 to 0.89, p = 0.016). In conclusion, the increase in prescription rates was greater for SGLT2is than for GLP1-RAs in patients with T2DM in a large integrated medical center and community primary care practices. Overall, prescription rates for eligible patients were low, and racial disparities were observed.

Glucagon-like Peptide-1 Receptor in the Human Hypothalamus Is Associated with Body Mass Index and Colocalizes with the Anorexigenic Neuropeptide Nucleobindin-2/Nesfatin-1.

Data on animals emphasize the importance of the neuronal glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) for feeding suppression, although it is unclear whether astrocytes participate in the transduction of anorectic GLP-1R-dependent signals. In humans, the brain circuitry underlying these effects remains insufficiently investigated. The present study aimed to explore GLP-1R protein expression in the human hypothalamus and its correlation with body mass index (BMI). Sections of hypothalamus from 28 autopsy cases, 11 with normal weight (BMI < 25 kg/m2) and 17 with non-normal weight (BMI ≥ 25 kg/m2), were examined using immunohistochemistry and double immunofluorescence labeling. Prominent GLP-1R immunoexpression was detected in neurons of several hypothalamic nuclei, including paraventricular, supraoptic, and infundibular nuclei; the lateral hypothalamic area (LH); and basal forebrain nuclei. Interestingly, in the LH, GLP-1R was significantly decreased in individuals with BMI ≥ 25 kg/m2 compared with their normal weight counterparts (p = 0.03). Furthermore, GLP-1R was negatively correlated (τb = −0.347, p = 0.024) with BMI levels only in the LH. GLP-1R extensively colocalized with the anorexigenic and antiobesogenic neuropeptide nucleobindin-2/nesfatin-1 but not with the astrocytic marker glial fibrillary acidic protein. These data suggest a potential role for GLP-1R in the regulation of energy balance in the human hypothalamus. In the LH, an appetite- and reward-related brain region, reduced GLP-1R immunoexpression may contribute to the dysregulation of homeostatic and/or hedonic feeding behavior. Possible effects of NUCB2/nesfatin-1 on central GLP-1R signaling require further investigation.

HypoMap-a unified single-cell gene expression atlas of the murine hypothalamus.

The hypothalamus plays a key role in coordinating fundamental body functions. Despite recent progress in single-cell technologies, a unified catalog and molecular characterization of the heterogeneous cell types and, specifically, neuronal subtypes in this brain region are still lacking. Here, we present an integrated reference atlas, 'HypoMap,' of the murine hypothalamus, consisting of 384,925 cells, with the ability to incorporate new additional experiments. We validate HypoMap by comparing data collected from Smart-Seq+Fluidigm C1 and bulk RNA sequencing of selected neuronal cell types with different degrees of cellular heterogeneity. Finally, via HypoMap, we identify classes of neurons expressing glucagon-like peptide-1 receptor (Glp1r) and prepronociceptin (Pnoc), and validate them using single-molecule in situ hybridization. Collectively, HypoMap provides a unified framework for the systematic functional annotation of murine hypothalamic cell types, and it can serve as an important platform to unravel the functional organization of hypothalamic neurocircuits and to identify druggable targets for treating metabolic disorders.

Management of hyperglycaemia in type 2 diabetes, 2022. A consensus report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD).

The American Diabetes Association and the European Association for the Study of Diabetes convened a panel to update the previous consensus statements on the management of hyperglycaemia in type 2 diabetes in adults, published since 2006 and last updated in 2019. The target audience is the full spectrum of the professional healthcare team providing diabetes care in the USA and Europe. A systematic examination of publications since 2018 informed new recommendations. These include additional focus on social determinants of health, the healthcare system and physical activity behaviours including sleep. There is a greater emphasis on weight management as part of the holistic approach to diabetes management. The results of cardiovascular and kidney outcomes trials involving sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists, including assessment of subgroups, inform broader recommendations for cardiorenal protection in people with diabetes at high risk of cardiorenal disease. After a summary listing of consensus recommendations, practical tips for implementation are provided.

Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD).

The American Diabetes Association and the European Association for the Study of Diabetes convened a panel to update the previous consensus statements on the management of hyperglycemia in type 2 diabetes in adults, published since 2006 and last updated in 2019. The target audience is the full spectrum of the professional health care team providing diabetes care in the U.S. and Europe. A systematic examination of publications since 2018 informed new recommendations. These include additional focus on social determinants of health, the health care system, and physical activity behaviors, including sleep. There is a greater emphasis on weight management as part of the holistic approach to diabetes management. The results of cardiovascular and kidney outcomes trials involving sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists, including assessment of subgroups, inform broader recommendations for cardiorenal protection in people with diabetes at high risk of cardiorenal disease. After a summary listing of consensus recommendations, practical tips for implementation are provided.

Recent guidelines for Non-Alcoholic Fatty Liver disease (NAFLD)/ Fatty Liver Disease (FLD): Are they already outdated and in need of supplementation?

Non-Alcoholic Fatty Liver Disease (NAFLD) is a highly prevalent disease and unmet clinical need that we have recently proposed to be renamed for simplicity and accuracy as Fatty Liver Disease (FLD), with specific subclassifications. It has been commonly associated with metabolic comorbidities, including obesity, type 2 diabetes (T2D), hypertension, and hyperlipidemia. Since no Federal and Drug Administration (FDA) approved treatments exist to date, recent guidelines recommend lifestyle interventions, bariatric surgery, and pharmacotherapy, i.e. glucagon-like peptide-1 receptor agonists (GLP-1RA), peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists, and SGLT-2 inhibitors for its treatment. A new and novel medication for the treatment of T2D, tirzepatide, a dual GIP/GLP-1RA, was approved by the FDA only one week after guidelines were published, and ongoing clinical trials demonstrate promising results not only for T2D but also for body weight and steatosis. Moreover, we realize that distinct subgroups exist under the umbrella of FLD and, thus, more precise therapeutic recommendations would be needed towards the goal of personalized medicine and therapeutics for these subgroups. As the metabolism field is moving forward very fast and as several molecules in development will most likely demonstrate benefits in NAFLD treatment in the foreseeable future, guidelines will need to be frequently updated. This rapid pace of change prompts us to propose that guidelines should exist as living online documents on the websites of professional societies, so that they continue being updated following and reflecting the rapid progress in this and other fields of medicine.

Glucose-sensing glucagon-like peptide-1 receptor neurons in the dorsomedial hypothalamus regulate glucose metabolism.

Glucagon-like peptide-1 (GLP-1) regulates energy homeostasis via activation of the GLP-1 receptors (GLP-1Rs) in the central nervous system. However, the mechanism by which the central GLP-1 signal controls blood glucose levels, especially in different nutrient states, remains unclear. Here, we defined a population of glucose-sensing GLP-1R neurons in the dorsomedial hypothalamic nucleus (DMH), by which endogenous GLP-1 decreases glucose levels via the cross-talk between the hypothalamus and pancreas. Specifically, we illustrated the sufficiency and necessity of DMHGLP-1R in glucose regulation. The activation of the DMHGLP-1R neurons is mediated by a cAMP-PKA-dependent inhibition of a delayed rectifier potassium current. We also dissected a descending control of DMHGLP-1R -dorsal motor nucleus of the vagus nerve (DMV)-pancreas activity that can regulate glucose levels by increasing insulin release. Thus, our results illustrate how central GLP-1 action in the DMH can induce a nutrient state-dependent reduction in blood glucose level.

Treatment of diabetes mellitus has borne much fruit in the prevention of cardiovascular disease.

Cardiovascular (CV) disease is the most alarming complication of diabetes mellitus (DM), and a strategy aiming at cardiovascular event prevention in diabetes mellitus has long been debated. Large landmark clinical trials have shown cardiovascular benefits of intensive glycemic control as a 'legacy effect' in newly diagnosed type 2 diabetes mellitus. In contrast, we have learned that excessive intervention aimed at strong glycemic control could cause unexpected cardiovascular death in patients who are resistant to treatments against hyperglycemia. It has also been shown that the comprehensive multifactorial intervention for cardiovascular risk factors that was advocated in the current guideline provided substantial cardiovascular event reduction. The impact of classical antidiabetic agents launched before 1990s on cardiovascular events is controversial. Although there are many clinical or observational studies assessing the impact of those agents on cardiovascular events, the conclusions are inconsistent owing to variable patient backgrounds and concomitant antidiabetic agents among the studies. Moreover, most of them were not large-scale, randomized, cardiovascular outcome trials. In contrast, GLP-1RA (glucagon-like peptide-1 receptor agonist) and SGLT2 (sodium-glucose cotransporter 2) inhibitors have demonstrated undeniable cardiovascular benefits in large-scale, randomized, controlled trials. Whereas GLP-1RAs decrease atherosclerotic disease, especially stroke, SGLT2 inhibitors mainly prevent heart failure. SGLT2 inhibitors are superior to GLP-1RAs with respect to hard renal outcomes. Therefore, it can be said that drugs such as GLP-1RAs and SGLT2 inhibitors that prevent cardiovascular events, in addition to their glucose-lowering effect, are incredible novel tools that we have gained for use in diabetic treatment.

A comparative transcriptomic analysis of glucagon-like peptide-1 receptor- and glucose-dependent insulinotropic polypeptide receptor-expressing cells in the hypothalamus

OBJECTIVE: The hypothalamus is a key region of the brain implicated in homeostatic regulation, and is an integral centre for the control of feeding behaviour. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are incretin hormones with potent glucoregulatory function through engagement of their respective cognate receptors, GLP-1R and GIPR. Recent evidence indicates that there is a synergistic effect of combining GIP- and GLP-1-based pharmacology on appetite and body weight. The mechanisms underlying the enhanced weight loss exhibited by GIPR/GLP-1R co-agonism are unknown. Gipr and Glp1r are expressed in the hypothalamus in both rodents and humans. To better understand incretin receptor-expressing cell populations, we compared the cell types and expression profiles of Gipr- and Glp1r-expressing hypothalamic cells using single-cell RNA sequencing. METHODS: Using Glp1r-Cre or Gipr-Cre transgenic mouse lines, fluorescent reporters were introduced into either Glp1r- or Gipr-expressing cells, respectively, upon crossing with a ROSA26-EYFP reporter strain. From the hypothalami of these mice, fluorescent Glp1rEYFP+ or GiprEYFP+ cells were FACS-purified and sequenced using single-cell RNA sequencing. Transcriptomic analysis provided a survey of both non-neuronal and neuronal cells, and comparisons between Glp1rEYFP+ and GiprEYFP + populations were made. RESULTS: A total of 14,091 Glp1rEYFP+ and GiprEYFP+ cells were isolated, sequenced and taken forward for bioinformatic analysis. Both Glp1rEYFP+ and GiprEYFP+ hypothalamic populations were transcriptomically highly heterogeneous, representing vascular cell types, oligodendrocytes, astrocytes, microglia, and neurons. The majority of GiprEYFP+ cells were non-neuronal, whereas the Glp1rEYFP+ population was evenly split between neuronal and non-neuronal cell types. Both Glp1rEYFP+ and GiprEYFP+ oligodendrocytes express markers for mature, myelin-forming oligodendrocytes. While mural cells are represented in both Glp1rEYFP+ and GiprEYFP+ populations, Glp1rEYFP+ mural cells are largely smooth muscle cells, while the majority of GiprEYFP+ mural cells are pericytes. The co-expression of regional markers indicate that clusters of Glp1rEYFP+ and GiprEYFP+ neurons have been isolated from the arcuate, ventromedial, lateral, tuberal, suprachiasmatic, and premammillary nuclei of the hypothalamus. CONCLUSIONS: We have provided a detailed comparison of Glp1r and Gipr cells of the hypothalamus with single-cell resolution. This resource will provide mechanistic insight into how engaging Gipr- and Glp1r-expressing cells of the hypothalamus may result in changes in feeding behaviour and energy balance.

[Effect of electroacupuncture on GLP-1R/PI3K/Akt protein pathway in mice with Parkinson's disease].

OBJECTIVE: To observe the effect of electroacupuncture(EA) on glucagon-like peptide-1 receptor (GLP-1R)/ phosphatidylinositol 3-kinase (PI3K)/ protein kinase B(Akt) protein pathway in the substantia nigra of mice with Parkinson's di-sease (PD)，so as to explore its underlying mechanisms in treatment of PD. METHODS: Forty-eight C57BL/6 male mice were randomly divided into normal, model, EA and inhibitor groups, with 12 mice in each group. PD mouse model was established by intragastrical administration of rotenone for 4 weeks. In the EA group, EA was applied at "Fengfu"(GV16), "Taichong"(LR3) and"Zusanli"(ST36) for 30 min, once daily, for 2 weeks. The mice of the inhibitor group received gavage of dipeptidyl peptidase-4 inhibitor ligliptin (10 mg·kg-1·d-1) once a day for 2 weeks. The behavioral scores of mice in each group were observed. The levels of tyrosine hydroxylase (TH) in serum and substantia nigra were detected by ELISA, and the protein relative expression levels of GLP-1R, phosphorylation of PI3K (p-PI3K) and phosphorylation of Akt (p-Akt) in substantia nigra of midbrain of mice were detected by Western blot. RESULTS: Compared with the normal group, the behavioral scores were significantly increased (P<0.01), TH levels in serum and substantia nigra, protein expression levels of GLP-1R, p-PI3K and p-Akt of the substantia nigra in the model group were significantly decreased (all P<0.01). After intervention and in comparison with the model group, the behavioral scores were significantly decreased (P<0.01), TH levels and the protein expression levels of GLP-1R, p-PI3K and p-Akt in both EA and inhibitor groups were significantly increased (all P<0.01). There were no significant differences in the abovementioned indexes between EA group and inhibitor group (all P>0.05), except for TH levels which were considerably down-regulated in the EA group relative to the inhibitor group (P<0.01, P<0.05). CONCLUSION: EA at GV16, LR3 and ST36 may increase the level of TH in serum and substantia nigra by up-regulating the activity of GLP-1R/PI3K/Akt protein pathway, and improve the behavioral performance of PD induced by rotenone.

Old and Novel Therapeutic Approaches in the Management of Hyperglycemia, an Important Risk Factor for Atherosclerosis.

Hyperglycemia is considered one of the main risk factors for atherosclerosis, since high glucose levels trigger multiple pathological processes, such as oxidative stress and hyperproduction of pro-inflammatory mediators, leading to endothelial dysfunction. In this context, recently approved drugs, such as glucagon-like-peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2i), could be considered a powerful tool for to reduce glucose concentration and cardiovascular risk. Interestingly, many patients with type 2 diabetes mellitus (T2DM) and insulin resistance have been found to be deficient in vitamin D. Recent studies pointed out the unfavorable prognostic values of T2DM and vitamin D deficiency in patients with cardiac dysfunction, either when considered individually or together, which shed light on the role of vitamin D in general health status. New evidence suggests that SGLT2i could adversely affect the production of vitamin D, thereby increasing the risk of fractures, which are common in patients with T2DM. Therefore, given the biological effects of vitamin D as an anti-inflammatory mediator and a regulator of endothelial function and calcium equilibrium, these new findings should be taken into consideration as well. The aim of this review is to gather the latest advancements regarding the use of antidiabetic and antiplatelet drugs coupled with vitamin D supplementation to control glucose levels, therefore reducing the risk of coronary artery disease (CAD).

Comparison of the effects of intracerebroventricular administration of glucagon-like peptides 1 and 2 on hypothalamic appetite regulating factors and sleep-like behavior in chicks.

Glucagon-like peptide (GLP)-1 and GLP-2, proglucagon-derived brain-gut peptides, function as anorexigenic neuropeptides in mammals. We previously showed that central administration of GLP-1 and GLP-2 potently suppressed food intake in chicks. GLP-1 and GLP-2 specifically activate their receptors GLP-1 receptor (GLP1R) and GLP-2 receptor (GLP2R), respectively in chickens. In adult chickens, GLP1R and GLP2R are expressed in different brain regions. These findings raise the hypothesis that both GLP-1 and GLP-2 function as anorexigenic peptides in the chicken brain but the mechanisms underlying the anorexigenic effects are different between them. In the present study, we compared several aspects of GLP-1 and GLP-2 in chicks. GLP1R mRNA levels in the brain stem and optic lobes were significantly higher than in other parts of the brain, whereas GLP2R mRNA was densely expressed in the telencephalon. Intracerebroventricular administration of either GLP-1 or GLP-2 significantly reduced the mRNA levels of corticotrophin releasing factor and AMP-kinase (AMPK) α1. The mRNA level of proopiomelanocortin was significantly increased, and those of AMPKα2 and GLP2R were significantly decreased by GLP-2, whereas the mRNA level of pyruvate dehydrogenase kinase 4 was significantly increased, and that of GLP1R was significantly decreased by GLP-1. Intracerebroventricular administration of either GLP-1 or GLP-2 induced sleep-like behavior in chicks. Our findings suggest that the anorexigenic peptides GLP-1 and GLP-2 induce similar behavioral changes in chicks, but the mechanism may differ between them.