Pharmacotherapy of type 2 diabetes: An update and future directions

UBC9 ameliorates diabetic cardiomyopathy by modulating cardiomyocyte mitophagy through NEDD4/RUNX2/PSEN2 axis

AIM

Diabetic cardiomyopathy (DCM) is one of the most significant cardiovascular complications in patients with diabetes. Ubiquitin conjugating enzyme 9 (UBC9) is the only SUMO-E2 enzyme that plays a key role in cardiomyocytes homeostasis. This study aimed to elucidate the roles and mechanisms of UBC9 in DCM development.

METHODS

We established cardiomyocyte-specific UBC9 knockout mice and UBC9-overexpressing mice in vivo. A DCM model was established by feeding a high-fat diet and administering a low-dose streptozotocin injection. Proteomics, H&E staining, Sirius Red staining, WGA staining, real-time PCR, and western blotting were performed to examine fibrosis, hypertrophy, and mitophagy in the myocardium. Neonatal mouse cardiomyocytes (NMCMs) were cultured in vitro and stimulated with palmitic acid, UBC9 overexpression adenovirus, and small interfering RNA to establish UBC9 overexpression or knockdown NMCMs. Real-time PCR, western blotting, and immunoprecipitation were employed to examine the roles and mechanisms of UBC9 in cardiomyocyte mitophagy.

RESULTS

The transcription and protein levels of UBC9 were significantly decreased in the myocardium of DCM mice. Cardiomyocyte-specific UBC9 knockout aggravated cardiac dysfunction, myocardial fibrosis, hypertrophy, and impaired mitophagy. Conversely, UBC9 overexpression produced opposite effects. UBC9 protected cardiomyocyte mitophagy independently of SUMOylation. UBC9 exerted protective effects against defective cardiomyocyte mitophagy by directly binding to NEDD4, enhancing RUNX2 ubiquitination and degradation, which in turn increased PSEN2 expression. Moreover, the impact of UBC9 on cardiomyocyte mitophagy was reversed upon PSEN2 knockdown.

CONCLUSIONS

UBC9 alleviated DCM development through the NEDD4/RUNX2/PSEN2 pathway. These findings offer novel insights into the potential of UBC9 as a therapeutic target for DCM.

α-Glucosidase Inhibition Mechanism and Anti-Hyperglycemic Effects of Flavonoids from Astragali Radix and Their Mixture Effects

Background: Inhibition of intestinal α-glucosidase is a key strategy for controlling postprandial hyperglycemia in diabetes. Astragali Radix (AR), a traditional medicinal and dietary herb widely consumed in China, is rich in flavonoids that are believed to exhibit hypoglycemic properties. Methods: A total of 29 AR-related flavonoids, including both original constituents and metabolites, were screened for α-glucosidase inhibitory activity using in vitro enzymatic assays. Mechanistic investigations were conducted through enzyme kinetics, circular dichroism (CD) spectroscopy, surface plasmon resonance (SPR), and molecular docking. The in vivo hypoglycemic effects were assessed using a postprandial hyperglycemic mouse model. Additionally, potential mixture effects of flavonoid combinations were evaluated. Results: Of the 29 flavonoids, 16 demonstrated significant α-glucosidase inhibitory activity, with five (C3, C17, C19, C28, and C29) identified as novel inhibitors. Structure-activity relationship (SAR) analysis revealed that hydroxylation, particularly at the C-3 position, enhanced activity, while glycosylation and methoxylation reduced it. Mechanistic studies demonstrated that these compounds bind to distinct amino acid residues within the active site of α-glucosidase, inducing conformational changes and exerting different types of inhibition, leading to varying inhibitory mechanisms. Additionally, 15 compounds reduced postprandial blood glucose levels, with C3, C16, C17, C19, and C28 confirmed as novel in vivo inhibitors. Notably, two compositions of flavonoids combined at their individually ineffective concentrations exhibited significant inhibitory effects. Conclusions: This study provides a comprehensive evaluation of AR-related flavonoids as α-glucosidase inhibitors and offers valuable insights for the development of highly effective, low-toxicity, flavonoid-based, antidiabetic therapeutics and functional foods.

The anti-diabetic PPARγ agonist Pioglitazone inhibits cell proliferation and induces metabolic reprogramming in prostate cancer

Prostate cancer (PCa) and Type 2 diabetes (T2D) often co-occur, yet their relationship remains elusive. While some studies suggest that T2D lowers PCa risk, others report conflicting data. This study investigates the effects of peroxisome proliferator-activated receptor (PPAR) agonists Bezafibrate, Tesaglitazar, and Pioglitazone on PCa tumorigenesis. Analysis of patient datasets revealed that high PPARG expression correlates with advanced PCa and poor survival. The PPARγ agonists Pioglitazone and Tesaglitazar notably reduced cell proliferation and PPARγ protein levels in primary and metastatic PCa-derived cells. Proteomic analysis identified intrinsic differences in mTORC1 and mitochondrial fatty acid oxidation (FAO) pathways between primary and metastatic PCa cells, which were further disrupted by Tesaglitazar and Pioglitazone. Moreover, metabolomics, Seahorse Assay-based metabolic profiling, and radiotracer uptake assays revealed that Pioglitazone shifted primary PCa cells' metabolism towards glycolysis and increased FAO in metastatic cells, reducing mitochondrial ATP production. Furthermore, Pioglitazone suppressed cell migration in primary and metastatic PCa cells and induced the epithelial marker E-Cadherin in primary PCa cells. In vivo, Pioglitazone reduced tumor growth in a metastatic PC3 xenograft model, increased phosho AMPKα and decreased phospho mTOR levels. In addition, diabetic PCa patients treated with PPAR agonists post-radical prostatectomy implied no biochemical recurrence over five to ten years compared to non-diabetic PCa patients. Our findings suggest that Pioglitazone reduces PCa cell proliferation and induces metabolic and epithelial changes, highlighting the potential of repurposing metabolic drugs for PCa therapy.

Exploring the Protective Effects of Traditional Antidiabetic Medications and Novel Antihyperglycemic Agents in Diabetic Rodent Models

Type 2 Diabetes (T2D) is a complex metabolic disorder that affects multiple organs, leading to severe complications in the pancreas, kidneys, liver, and heart. Prolonged hyperglycemia, along with oxidative stress and chronic inflammation, plays a crucial role in accelerating tissue damage, significantly increasing the risk of diabetic complications such as nephropathy, hepatopathy, and cardiovascular disease. This review evaluates the protective effects of various antidiabetic treatments on organ tissues affected by T2D, based on findings from experimental animal models. Metformin, a first-line antidiabetic agent, has been widely recognized for its ability to reduce inflammation and oxidative stress, thereby mitigating diabetes-induced organ damage. Its protective role extends beyond glucose regulation, offering benefits such as improved mitochondrial function and reduced fibrosis in affected tissues. In addition to traditional therapies, new classes of antidiabetic drugs, including sodium-glucose co-transporter-2 inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists not only improve glycemic control but also exhibit nephroprotective and cardioprotective properties by reducing glomerular hyperfiltration, oxidative stress, and inflammation. Similarly, GLP-1 receptor agonists have been associated with reduced hepatic steatosis and enhanced cardiovascular function. Preclinical studies suggest that tirzepatide, a dual GLP-1/gastric inhibitory polypeptide receptor agonist may offer superior metabolic benefits compared to conventional GLP-1 agonists by improving β-cell function, enhancing insulin sensitivity, and reducing fatty liver progression. Despite promising preclinical results, differences between animal models and human physiology pose a challenge. Further clinical research is needed to confirm these effects and refine treatment strategies. Future T2D management aims to go beyond glycemic control, emphasizing organ protection and long-term disease prevention.

Discovery of Hypoglycemic and Cardiovascular Drugs as Effective Inhibitors on Human Pancreatic Lipase

Obesity is closely related to the occurrence and development of many diseases, such as diabetes, hypertension, and hyperlipidemia. As an important digestive enzyme, human pancreatic lipase (hPL) is involved in the metabolism and absorption of dietary fat and is a key target of overweight and obesity. Therefore, the inhibition of hPL enzyme is a feasible strategy for the prevention and treatment of obesity. In this study, we collected a series of marketed hypoglycemic and cardiovascular drugs and evaluated their inhibitory activity against hPL. Among them, ticagrelor (HC-14), prasugrel (HC-18), amlodipine (HC-26), simvastatin (HC-32), and lovastatin (HC-33) had strong inhibitory activity against hPL. In order to further clarify the inhibition mechanism, inhibition kinetics and molecular docking were carried out, and results revealed that HC-14 was a mixed inhibitory manner on hPL activity. HC-14 also showed similar inhibitory effect on human carboxylesterase 2 (hCES2), but poor inhibitory effect on other five serine hydrolases. Further studies showed that HC-14 significantly inhibited hPL activity in AR42J cells, resulting in dose-dependent inhibition. Overall, the above results suggest that ticagrelor is a cardiovascular drug that inhibits hPL, which also provides an important reference for the search and development of other drugs for the treatment of obesity.

GABP Promotes Mesangial Cell Proliferation and Renal Fibrosis Through GLI1 in Diabetic Nephropathy

Abnormal proliferation of mesangial cells is a hallmark of diabetic nephropathy (DN). However, the cellular signaling mechanisms that regulate this proliferation remain poorly understood. In this study, it is demonstrated that GA-binding protein (GABP), a member of the ETS family of transcription factors composed of GABPα and GABPβ, plays a significant role in the development of renal fibrosis by modulating mesangial cell proliferation. Notably, the deficiency of GABP in mesangial cells inhibits hyperglycemia-induced proliferation and mitigates renal fibrosis in a murine model of type 2 diabetes mellitus (T2DM). RNA sequencing analysis identifies GLI Family Zinc Finger 1 (GLI1) as the principal downstream effector of GABP in diabetic mice, serving as a crucial regulator of the G1/S transition within the cell cycle. Subsequent investigations have demonstrated that GABP interacts with the GLI1 promoter, facilitating mesangial cell proliferation via GLI1-dependent pathways. This is evidenced by the fact that GLI1 knockdown abrogates the proliferation of mesangial cells with GABP overexpression. Consequently, GABP emerges as a pivotal regulator of renal fibrosis and represents a promising therapeutic target for the treatment of diabetic nephropathy.

Multi Targeted Activity of Cocculus hirsutus through Modulation of DPP-IV and PTP-1B Leading to Enhancement of Glucose Uptake and Attenuation of Lipid Accumulation

Multi-targeted therapies are gaining attention in the management of multifactorial diseases due to their poly pharmacology, enhanced potency and reduced toxicity. Metabolic disorders like Type 2 diabetes mellitus (T2DM) and obesity necessitate multi-targeted therapy to improve insulin sensitivity, regulate glucose homeostasis and support weight loss. Medicinal plants rich in bioactive compounds exhibit multi-targetted action with minimal side effects. In the current study, Cocculus hirsutus methanol extract (CME) and its hydromethanolic fraction (HMF) were investigated for their multi-target potential. Significant inhibition of Dipeptidyl peptidase IV (DPP-IV), a key enzyme in glucose metabolism was observed due to CME (54%) and HMF (70%) at 10 µg/ml and 1 µg/ml respectively. Protein Tyrosine Phosphatase 1B (PTP-1B), involved in the regulation of insulin signalling, was also inhibited by CME (67%) and HMF (73%) at 10 µg/ml concentration. An increase in glucose uptake was observed due to CME (62% and 65%) and HMF (63% and 68%) in 3T3-L1 adipocytes and L6 myotubes at 100 ng/ml. Further, investigation of HMF showed a decrease in lipid accumulation by 63% at 1 µg/ml in 3T3-L1 cells. Interestingly, HMF improved insulin sensitivity by upregulating GLUT4 expression (p < 0.05) via the PI3K/AKT pathway in both 3T3-L1 adipocytes and L6 myotubes. An inhibition in lipid accumulation was also observed by suppression of Peroxisome proliferator-activated receptor γ (PPARγ) (p < 0.05), a key regulator of adipogenesis in 3T3-L1 adipocytes. Gas chromatography-mass spectrometry analysis of the HMF showed the major component to be 3-methylmannoside (26.52%).

Hyperglycemia and type 2 diabetes mellitus associate with postoperative recurrence in chronic rhinosinusitis patients

OBJECTIVE

To investigate the associations between fasting blood glucose (FBG) and type 2 diabetes mellitus (T2DM) and the risk of postoperative CRS recurrence.

METHODS

A retrospective cohort study was conducted on clinical data of CRS patients who underwent surgery at our center between February 2019 and March 2022 and were followed up until June 2023. All CRS patients were categorized into two subgroups based on the presence of T2DM and postoperative recurrence. The Kaplan-Meier survival curves and binary logistic regression analyses were performed to examine the associations between FBG, T2DM, and the risk of postoperative CRS recurrence.

RESULTS

1163 CRS patients were enrolled, including 134 in the T2DM group and 276 in the recurrent group. The recurrence rate in the T2DM group was significantly higher than that in the non-T2DM group (P < 0.05). T2DM prevalence and FBG levels were higher in the recurrent CRS group than in the non-recurrent CRS group (P < 0.05). The Kaplan-Meier survival curves and unadjusted and adjusted logistic regression models showed that T2DM was an independent risk factor for postoperative CRS recurrence (P < 0.05). Moreover, multivariate logistic regression analysis suggested that FBG, CRS duration, and allergic rhinitis were associated with the risk of postoperative CRS recurrence (P < 0.05).

CONCLUSION

Elevated FBG levels and accompanying T2DM were associated with an increased risk of postoperative CRS recurrence, which was independent of traditional risk factors. CRS duration and accompanying allergic rhinitis were also proven to be potential risk factors for postoperative CRS recurrence.

Loss of DDB2 in type II diabetes mellitus induces dysregulated ubiquitination of KMT2A in lipid metabolism disorders

The disorders of glucose and lipid metabolism contribute to severe diseases, including cardiovascular disease, diabetes, and fatty liver. Here, we identified DNA damage-binding protein 2 (DDB2), an E3 ubiquitin ligase, as a pivotal regulator of lipid metabolism disorders in type II diabetes mellitus (T2DM). A mouse model of T2DM and primary mouse hepatocytes with steatosis were induced. DDB2 overexpression alone or in combination with lysine N-methyltransferase 2 A (KMT2A) overexpression vectors were delivered into db/db mice and in vitro hepatocytes. DDB2 was expressed poorly, while KMT2A was expressed highly in liver tissues and primary hepatocytes of db/db mice. DDB2 ameliorated glucose intolerance and insulin resistance, decreased liver/body weight ratio, downregulated expression of lipogenesis-associated proteins (SREBP1, FASN, and SCD1) and gluconeogenesis-related proteins (PEPCK and G6Pase) in liver tissues and cells, and decreased triglyceride and total cholesterol levels in steatotic hepatocytes. DDB2 reduced KMT2A expression through ubiquitination modification. Overexpression of KMT2A promoted insulin resistance, lipogenesis and lipid deposition, and glycogen accumulation in the presence of DDB2. Overall, our data demonstrate that DDB2 alleviates hepatic lipogenesis and lipid deposition via degradation of KMT2A, thereby repressing lipid metabolism disorders in T2DM.

Targeted gut microbiome therapy: Applications and prospects of probiotics, fecal microbiota transplantation and natural products in the management of type 2 diabetes

Type 2 diabetes mellitus (T2DM) is considered as one of the most pressing public health challenges worldwide. Studies have shown significant differences in the gut microbiota between healthy individuals and T2DM patients, suggesting that gut microorganisms may play a key role in the onset and progression of T2DM. This review systematically summarizes the relationship between gut microbiota and T2DM, and explores the mechanisms through which gut microorganisms may alleviate T2DM. Additionally, it evaluates the potential of probiotics, fecal microbiota transplantation (FMT)/virome transplantation (FVT), and natural products in modulating gut microbiota to treat T2DM. Although existing studies have suggested that these interventions may delay or even halt the progression of T2DM, most research remained limited to animal models and observational clinical studies, with a lack of high-quality clinical data. This has led to an imbalance between theoretical research and clinical application. Although some studies have explored the regulatory role of the gut virome on the gut microbiota, research in this area remains in its early stages. Based on these current studies, future research should be focused on large-scale, long-term clinical studies and further investigation on the potential role of the gut virome in T2DM. In conclusion, this review aims to summarize the current evidence and explore the applications of gut microbiota in T2DM treatment, as well as providing recommendations for further investigation in this field.

Comparative efficacy and safety of dipeptidyl peptidase-4 inhibitors in adults with type 2 diabetes mellitus: A network meta-analysis

AIMS

We have compiled updated evidence on the benefits and drawbacks of dipeptidyl peptidase-4 (DPP-4) inhibitors in treating type 2 diabetes mellitus.

MATERIALS AND METHODS

We systematically searched PubMed, Embase, Cochrane Library, and ClinicalTrials.gov (as of 20 May 2024). Effect estimates were calculated using network meta-analysis under the frequentist framework. The P-score established the ranking of competing treatments.

RESULTS

The authors incorporated 58 studies containing data from a substantial sample size of 21 332 patients. Based on evidence of high and moderate certainty, respectively, teneligliptin and vildagliptin were found to be superior to all other DPP-4 inhibitors in lowering haemoglobin A1c (mean difference [MD] -0.81%, 95% CI -1.03, -0.60) and fasting blood glucose (MD -1.18 mmol/L, 95% CI -1.56, -0.81) compared to placebo. The absence of conclusive differences between interventions for serious adverse events was supported by evidence, which was interpreted with low to very low certainty.

CONCLUSIONS

In adults with type 2 diabetes, teneligliptin was most effective for HbA1c control, and vildagliptin for fasting blood glucose. No significant differences in serious adverse events were noted among DPP-4 inhibitors compared to placebo. Given the therapeutic significance of these findings, more studies are needed to explore this issue more thoroughly.

Protective role of sulforaphane in lipid metabolism-related diseases

Sulforaphane (SFN) is a phytochemical bioactive substance commonly found in cruciferous plants, such as broccoli and mustard. It has been reported to possess antibacterial, anti-inflammatory, anti-oxidant, anti-cancer and autophagy regulating properties. Recent studies have revealed that SFN regulates fat metabolism both in vivo and in vitro through various mechanisms, including alleviating endoplasmic reticulum stress, inhibiting inflammatory response and improving mitochondrial dysfunction, involving Nrf2/ARE, NF-κB, NLRP3 inflammasome, HDAC8-PGC1α axis and other signaling pathways. By curbing complications associated with abnormal fat metabolic diseases, SFN exhibits therapeutic effects on conditions like obesity, fatty liver disease, atherosclerosis, type 2 diabetes, etc., with minimal side effects. Therefore, it holds promise as a potential alternative treatment for lipid metabolism-related diseases. Although its extraction method has been matured, the thermal instability and preservation difficulties of SFN limit its clinical promotion. More effective and low-cost methods to improve the stability and production of SFN remain to be further studied. This paper reviews the physiological and biological activities of SFN, and summarizes the protective effects and molecular mechanisms of SFN in diseases related to abnormal lipid metabolism. Additionally, it proposes potential challenges, possible solutions and future research directions in the clinical application of SFN.

Transgenerational inheritance of diabetes susceptibility in male offspring with maternal androgen exposure

Androgen exposure (AE) poses a profound health threat to women, yet its transgenerational impacts on male descendants remain unclear. Here, employing a large-scale mother-child cohort, we show that maternal hyperandrogenism predisposes sons to β-cell dysfunction. Male offspring mice with prenatal AE exhibited hyperglycemia and glucose intolerance across three generations, which were further exacerbated by aging and a high-fat diet. Mechanistically, compromised insulin secretion underlies this transgenerational susceptibility to diabetes. Integrated analyses of methylome and transcriptome revealed differential DNA methylation of β-cell functional genes in AE-F1 sperm, which was transmitted to AE-F2 islets and further retained in AE-F2 sperm, leading to reduced expression of genes related to insulin secretion, including Pdx1, Irs1, Ptprn2, and Cacna1c. The methylation signatures in AE-F1 sperm were corroborated in diabetic humans and the blood of sons with maternal hyperandrogenism. Moreover, caloric restriction and metformin treatments normalized hyperglycemia in AE-F1 males and blocked their inheritance to offspring by restoring the aberrant sperm DNA methylations. Our findings highlight the transgenerational inheritance of impaired glucose homeostasis in male offspring from maternal AE via DNA methylation changes, providing methylation biomarkers and therapeutic strategies to safeguard future generations' metabolic health.

Autophagy-lysosome pathway in insulin & glucagon homeostasis

Lysosome, a highly dynamic organelle, is an important nutrient sensing center. They utilize different ion channels and transporters to complete the mission in degradation, trafficking, nutrient sensing and integration of various metabolic pathways to maintain cellular homeostasis. Glucose homeostasis relies on tightly regulated insulin secretion by pancreatic β cells, and their dysfunction is a hallmark of type 2 diabetes. Glucagon also plays an important role in hyperglycemia in diabetic patients. Currently, lysosome has been recognized as a nutrient hub to regulate the homeostasis of insulin and other hormones. In this review, we will discuss recent advances in understanding lysosome-mediated autophagy and lysosomal proteins involved in maintaining insulin and glucagon homeostasis, as well as their contributions to the etiology of diabetes.

Clinical features of pneumatosis intestinalis induced by alpha- glucosidase inhibitor in patients with type 2 diabetes mellitus: a single center retrospective study

Purpose

Pneumatosis intestinalis (PI) is a rare but significant side effect associated with the use of alpha-glucosidase inhibitor (αGI) in the treatment of diabetes. This study aims to analyze the clinical features of PI induced by αGIs in patients with type 2 diabetes mellitus.

Methods

We conducted a retrospective analysis of patients diagnosed with PI between January 2018 and December 2023. Data collected included demographic characteristics, clinical symptoms and signs, laboratory findings, imaging results, endoscopic manifestations, treatments, and outcomes. Clinical characteristics were compared between patients who used acarbose and those who did not.

Results

A total of 48 patients with PI were included in the study, of whom 22 had used acarbose and 26 had not. The acarbose taken group was significantly older than the acarbose untaken group. Additionally, the prevalence of coronary heart disease and hypertension was markedly higher in patients taking acarbose. Importantly, total bilirubin levels were lower in those with PI who were on acarbose therapy.

Conclusion

Our findings highlight the need for increased vigilance regarding the potential development of PI in older diabetic patients with cardiovascular conditions following αGI administration. Timely intervention is crucial to prevent adverse outcomes. This study offers valuable insights for the future management of αGI in diabetes treatment.

Type 2 Diabetes Mellitus: A Comprehensive Review of Pathophysiology, Comorbidities, and Emerging Therapies

Humans are perhaps evolutionarily engineered to get deeply addicted to sugar, as it not only provides energy but also helps in storing fats, which helps in survival during starvation. Additionally, sugars (glucose and fructose) stimulate the feel-good factor, as they trigger the secretion of serotonin and dopamine in the brain, associated with the reward sensation, uplifting the mood in general. However, when consumed in excess, it contributes to energy imbalance, weight gain, and obesity, leading to the onset of a complex metabolic disorder, generally referred to as diabetes. Type 2 diabetes mellitus (T2DM) is one of the most prevalent forms of diabetes, nearly affecting all age groups. T2DM is clinically diagnosed with a cardinal sign of chronic hyperglycemia (excessive sugar in the blood). Chronic hyperglycemia, coupled with dysfunctions of pancreatic β-cells, insulin resistance, and immune inflammation, further exacerbate the pathology of T2DM. Uncontrolled T2DM, a major public health concern, also contributes significantly toward the onset and progression of several micro- and macrovascular diseases, such as diabetic retinopathy, nephropathy, neuropathy, atherosclerosis, and cardiovascular diseases, including cancer. The current review discusses the epidemiology, causative factors, pathophysiology, and associated comorbidities, including the existing and emerging therapies related to T2DM. It also provides a future roadmap for alternative drug discovery for the management of T2DM.

Human subjects with impaired beta-cell function and glucose tolerance have higher levels of intra-islet intact GLP-1

AIMS

A number of studies have suggested that pancreatic α cells produce intact GLP-1, thereby constituting a gut-independent paracrine incretin system. However, the debate on whether human α cells contain intact GLP-1 and whether this relates to the presence of diabetes is still ongoing. This study aimed to determine the presence of proglucagon-derived peptides, including GLP-1 isoforms, in pancreas biopsies obtained during partial pancreatectomy from metabolically profiled human donors, stratified according to pre-surgery glucose tolerance.

METHODS

We enrolled 61 individuals with no known history of type 2 diabetes (31F/30M, age 64.6 ± 10.6 yrs., BMI 24.2 ± 3.68 kg/m2) scheduled for partial pancreatectomy for periampullary neoplasm. Differences in glucose tolerance and insulin secretion/sensitivity were assessed using preoperative 2 h OGTT, 4 h-Mixed Meal Test and Hyperinsulinemic Euglycemic Clamp. Subjects were subsequently classified as normal glucose tolerant (NGT, n = 19), impaired glucose tolerant (IGT, n = 20) or newly diagnosed diabetes (DM) (n = 22). We measured total GLP-1, intact GLP-1, glucagon, insulin, and C-peptide in pancreas biopsies and plasma from these subjects and correlated the results with their secretory and metabolic parameters.

RESULTS

Extractable levels of total GLP-1 were 23.9 ± 2.66 pmol/g, while intact GLP-1 levels were 1.15 ± 0.18 pmol/g. When we examined proglucagon derived peptides (adjusted for glucagon levels), in subjects classified according to glucose tolerance, we observed similar levels of total GLP-1, however, intact GLP-1 was significantly increased in IGT and DM groups and inversely associated with beta cell glucose sensitivity and insulin secretion in vivo.

CONCLUSIONS

Our data show that development of glucose intolerance and beta cell dysfunction are significantly associated with increased levels of intra-islet intact GLP-1, a potentially beneficial adaptation of the paracrine regulation of insulin secretion in type 2 diabetes.

Differences in splicing factors may predict type 2 diabetes remission in the CORDIOPREV study

Alternative splicing is a post-transcriptional process resulting in multiple protein isoforms from a single gene. Abnormal splicing may lead to metabolic diseases, including type 2 diabetes mellitus (T2DM). To identify the splicing factor expression that predicts T2DM remission in coronary heart disease (CHD) patients, we identified newly diagnosed T2DM at baseline (n = 190) from the CORDIOPREV study. Patients were classified as Responders (T2DM remission during 5 years without antidiabetic drugs) or non-Responders. Baseline dysregulation in 5 splicing factors (MBNL1, RBM5, hnRNP G/RBMX, CD44, NT5E) distinguished Responders from non-Responders. Adding these factors to clinical variables [AUC = 0.67], insulin resistance, and beta-cell indexes [AUC = 0.76], improved T2DM remission prediction [AUC = 0.80]. Cox regression analysis showed those with higher remission scores had a 2.63-fold increased remission probability. To conclude, a set of splicing factors that contribute to predicting T2DM remission in patients with CHD has been identified. Further research is needed to elucidate these findings' clinical relevance.

Sphingosine-1-phosphate in the regulation of diabetes mellitus: a scientometric study to an in-depth review

Diabetes is a significant global health issue, causing extensive morbidity and mortality, and represents a serious threat to human health. Recently, the bioactive lipid molecule Sphingosine-1-Phosphate has garnered considerable attention in the field of diabetes research. The aim of this study is to comprehensively understand the mechanisms by which Sphingosine-1-Phosphate regulates diabetes. Through comprehensive bibliometric analysis and an in-depth review of relevant studies, we investigated and summarized various mechanisms through which Sphingosine-1-Phosphate acts in prediabetes, type 1 diabetes, type 2 diabetes, and their complications (such as diabetic nephropathy, retinopathy, cardiovascular disease, neuropathy, etc.), including but not limited to regulating lipid metabolism, insulin sensitivity, and inflammatory responses. This scholarly work not only unveils new possibilities for using Sphingosine-1-Phosphate in diabetes treatment but also offers fresh insights and recommendations for future research directions to researchers.

Reversal of insulin resistance to combat type 2 diabetes mellitus by newer thiazolidinedione's in fructose induced insulin resistant rats

In our pursuit of discovering new antidiabetic agents to manage type 2 diabetes mellitus (T2DM), our approach aimed to identify the bioactive feature/pharmacophore responsible for PPAR-γ expression, as it is accountable for the glucose homeostasis and lipid metabolism. This was achieved by pharmacophore model generation, screening of rationally designed newer thiazolidinedione's library, identifying synthesizing and characterizing the top ten molecules (5a-5j) for their (Invitro & invivo) antidiabetic activity. Preliminary screening of all the ligands by Invitro glucose uptake assay in L6 myotubes (skeletal muscle cell line of rats) revealed compound 5b and 5f stimulated the glucose uptake with 79.29 ± 1.02 % and 74.58 ± 1.02 % respectively compared to pioglitazone with 82.36 ± 0.98 %. This was validated by PPAR-γ TF expression assay, which highlighted a dose dependent increase in transactivation of PPAR-γ. These compounds 5b and 5f were evaluated in fructose induced insulin resistance rat model. Where the treatment with 5b and 5f markedly increased the exogenous clearance of glucose and exogenous insulin via OGTT and ITT respectively, also improved the glucose utilization by significantly increasing content of glycogen and uptake of glucose in rat hemidiaphragm and reversed insulin resistance. Likewise a significant decreased in the VLDL and triglyceride levels was seen in 5b and 5f treated groups compared to insulin resistant (IR) group. It improved glycogenesis by catabolism of glucose and maintained glycaemic control. Similarly it had marked action on enzymatic oxidative biomarkers. Compound 5b displayed better, improved T1/2 (half-life) of 4.21 h and Kel (elimination constant) of 0.381 was noticed in comparison to compound 5f indicating the pharmacokinetic profile. Insilico studies like DFT calculations refined the geometry of 5b and 5f ligands, docking and molecular simulation provided the insights in binding affinity, dynamic behaviour and stability of ligands in PPAR-γ ligand binding domain. MM/GBSA provided the energetics of 5b and 5f in binding pocket. Finally network pharmacology identified ADIPOQ (adiponectin), NR1C3 (PPAR-γ), SLC2A4 (GLUT4), and LEP (leptin) proteins associate with compound 5b and 5f and enriched in Adipocytokine pathway, and PPAR-γ signaling pathway.

Evaluation of Hypoglycemic Polyphenolic Compounds in Blueberry Extract: Functional Effects and Mechanisms

Blueberries are rich in polyphenols, which exhibit significant anti-diabetic activity. In this study, polyphenolic compounds with potential hypoglycemic activity were identified from blueberry polyphenol extract (BPE). This research focused on assessing the hypoglycemic effects of BPE and its polyphenolic compounds (dihydroquercetin and gallic acid) on diabetic mice induced by streptozotocin (STZ) and high-fat diet (HFD), as well as the related fundamental mechanisms. The findings revealed that BPE treatment effectively reduced levels of fasting blood glucose (FBG) by decreasing hepatic oxidative stress, regulating lipid metabolism disorders and improving insulin resistance. Investigations into the insulin signaling pathway revealed that BPE can modulate the expression of Egfr, Insr, Irs-1, Pi3k and Akt, thereby influencing glucose metabolism. This study provides a research foundation for considering blueberry polyphenols as a nutritional dietary supplement for the prevention and intervention of diabetes.

Comparative efficacy of THR-β agonists, FGF-21 analogues, GLP-1R agonists, GLP-1-based polyagonists, and Pan-PPAR agonists for MASLD: A systematic review and network meta-analysis

AIMS

To compare the efficacy of thyroid hormone receptor beta (THR-β) agonists, fibroblast growth factor 21 (FGF-21) analogues, glucagon-like peptide-1 receptor agonists (GLP-1RAs), GLP-1-based polyagonists, and pan-peroxisome proliferator-activated receptor (Pan-PPAR) agonists in the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

A database search for relevant randomized double-blind controlled trials published until July 11, 2024, was conducted. Primary outcomes were the relative change in hepatic fat fraction (HFF) and liver stiffness assessed non-invasively by magnetic resonance imaging proton density fat fraction and elastography. Secondary outcomes included histology, liver injury index, lipid profile, glucose metabolism, blood pressure, and body weight.

RESULTS

Twenty-seven trials (5357 patients with MASLD) were identified. For HFF reduction, GLP-1-based polyagonists were most potentially effective (mean difference [MD] -51.47; 95 % confidence interval [CI]: -68.25 to -34.68; surface under the cumulative ranking curve [SUCRA] 84.9) vs. placebo, followed by FGF-21 analogues (MD -47.08; 95 % CI: -58.83 to -35.34; SUCRA 75.5), GLP-1R agonists (MD -37.36; 95 % CI: -69.52 to -5.21; SUCRA 52.3) and THR-β agonists (MD -33.20; 95 % CI: -43.90 to -22.51; SUCRA 36.9). For liver stiffness, FGF-21 analogues were most potentially effective (MD -9.65; 95 % CI: -19.28 to -0.01; SUCRA 82.2) vs. placebo, followed by THR-β agonists (MD -5.79; 95 % CI: -9.50 to -2.09; SUCRA 58.2), and GLP-1RAs (MD -5.58; 95 % CI: -15.02 to 3.86; SUCRA 54.7). For fibrosis improvement in histology, GLP-1-based polyagonists were most potentially effective, followed by FGF-21 analogues, THR-β agonists, Pan-PPAR agonists, and GLP-1R agonists; For MASH resolution in histology, GLP-1-based polyagonists were most potentially effective, followed by THR-β agonists, GLP-1R agonists, FGF-21 analogues, and Pan-PPAR agonists. THR-β agonists are well-balanced in liver steatosis and fibrosis, and excel at improving lipid profiles; FGF-21 analogues are effective at improving steatosis and particularly exhibit strong antifibrotic abilities. GLP-1R agonists showed significant benefits in improving liver steatosis, glucose metabolism, and body weight. GLP-1-based polyagonists have demonstrated the most potential efficacy overall in terms of comprehensive curative effect. Pan-PPAR agonists showed distinct advantages in improving liver function and glucose metabolism.

CONCLUSION

These results illustrate the relative superiority of the five classes of therapy in the treatment of MASLD and may serve as guidance for the development of combination therapies.

New natural protein tyrosine phosphatase 1B inhibitors from Gynostemma pentaphyllum

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease mainly caused by insulin resistance, which can lead to a series of complications such as cardiovascular disease, retinopathy, and its typical clinical symptom is hyperglycaemia. Glucosidase inhibitors, including Acarbose, Miglitol, are commonly used in the clinical treatment of hypoglycaemia. In addition, Protein tyrosine phosphatase 1B (PTP1B) is also an important promising target for the treatment of T2DM. Gynostemma pentaphyllum is a well-known oriental traditional medicinal herbal plant, and has many beneficial effects on glucose and lipid metabolism. In the present study, three new and nine known dammarane triterpenoids isolated from G. pentaphyllum, and their structures were elucidated by spectroscopic methods including HR-ESI-MS,1H and 13C NMR and X-ray crystallography. All these compounds were evaluated for inhibitory activity against α-glucosidase, α-amylase and PTP1B. The results suggested that compounds 7∼10 were potential antidiabetic agents with significantly inhibition activity against PTP1B in a dose-dependent manner.

Effect of diabetes mellitus type 2 and sulfonylurea on colorectal cancer development: a case-control study

BACKGROUND AND AIMS

Colorectal cancer (CRC) is a significant global health concern, with studies estimating a rise in new cases to 2.5 million by 2035. Type 2 diabetes (T2D) is also a growing issue, with an estimated 642 million adults affected by 2040. However, the relationship between T2D, its medications, and CRC remains unclear.

MATERIALS AND METHODS

This case-control study includes 810 controls without CRC and 684 cases with CRC admitted to Rasoul-Akram and Firouzgar Hospitals from September 2019 to 2023. Adjusted and unadjusted odds ratios (OR) were calculated to investigate the effect of T2D and sulfonylurea consumption on the chance of CRC development, using univariate and multivariate logistic regression analyses. The relationship between T2D and the clinicopathological features of the tumor was investigated.

RESULTS

The results show that the effect of T2D on CRC is significant based on unadjusted OR (OR = 1.39, CI = 1.07, 1.81) and insignificant in adjusted OR (OR = 0.67, CI = 0.37, 1.20). The effect of sulfonylurea consumption on CRC was significant in both unadjusted (OR = 2.39, CI = 1.40, 4.09) and adjusted ORs (OR = 2.35, CI = 1.12, 4.91). All analyses related to the relationship between T2D and tumor clinicopathological characteristics were insignificant.

CONCLUSION

This study found an insignificant association between type 2 diabetes and the chance of CRC development in an adjusted state. Sulfonylurea consumption was also associated with a higher chance of CRC development among patients with T2D. These findings have implications for clinical practice and public health strategies in CRC prevention for patients with T2D.

Lesion Localization and Limb Outcomes in Elderly Patients with and Without Type 2 Diabetes Mellitus Who Undergo Atherectomy-Assisted Endovascular Revascularization due to Symptomatic Peripheral Artery Disease

Background/Objectives: Type 2 diabetes mellitus (T2DM) represents a major risk factor for peripheral artery disease (PAD). We aimed to evaluate the impact of T2DM on lesion localization and complexity, clinical presentation by Rutherford categories, and limb outcomes in elderly patients with symptomatic PAD undergoing endovascular revascularization. Methods: Five hundred consecutive patients with symptomatic infra-inguinal PAD who underwent rotational atherectomy-assisted endovascular revascularization were included. PAD clinical presentation and lesion localization were recorded. The primary endpoints were clinically driven target lesion revascularization (CD-TLR) and major amputation rates during follow-up. Results: Overall, 245/500 (49.0%) patients had T2DM, whereas 179 (35.8%) presented with lifestyle limiting claudication and 321 (64.2%) with critical limb-threatening ischemia (CLTI). Median age was 78.0 (IQR = 70.0-84.0) years, and 201 (40.2%) patients were female. The presence of T2DM was significantly more frequent in patients with CLTI vs. those with claudication (58.6 vs. 31.8%; p < 0.001). Furthermore, the percentage of patients with below-the-knee (BTK) lesions was significantly higher in patients with vs. without T2DM (40.7 vs. 27.5%, p = 0.0002). During median follow-up of 21.9 (IQR = 12.8-28.8) months, CD-TLR rates were similar in patients with vs. without T2DM (HR = 1.2, 95%CI = 0.8-2.0, p = 0.39). However, patients with T2DM had a ~5.5-fold increased risk for major above-the-ankle amputation (HR = 5.5, 95%CI = 1.6-19.0, p = 0.007). After adjustment for age, gender, lesion complexity, and calcification, T2DM remained predictive for major amputation (p = 0.04). Conclusions: T2DM is more frequently associated with CLTI, BTK-PAD, and amputations despite successful endovascular revascularization. More stringent surveillance of patients with PAD and T2DM is warranted to prevent atherosclerosis-related complications.

Type 2 diabetes mellitus in adults: pathogenesis, prevention and therapy

Type 2 diabetes (T2D) is a disease characterized by heterogeneously progressive loss of islet β cell insulin secretion usually occurring after the presence of insulin resistance (IR) and it is one component of metabolic syndrome (MS), and we named it metabolic dysfunction syndrome (MDS). The pathogenesis of T2D is not fully understood, with IR and β cell dysfunction playing central roles in its pathophysiology. Dyslipidemia, hyperglycemia, along with other metabolic disorders, results in IR and/or islet β cell dysfunction via some shared pathways, such as inflammation, endoplasmic reticulum stress (ERS), oxidative stress, and ectopic lipid deposition. There is currently no cure for T2D, but it can be prevented or in remission by lifestyle intervention and/or some medication. If prevention fails, holistic and personalized management should be taken as soon as possible through timely detection and diagnosis, considering target organ protection, comorbidities, treatment goals, and other factors in reality. T2D is often accompanied by other components of MDS, such as preobesity/obesity, metabolic dysfunction associated steatotic liver disease, dyslipidemia, which usually occurs before it, and they are considered as the upstream diseases of T2D. It is more appropriate to call "diabetic complications" as "MDS-related target organ damage (TOD)", since their development involves not only hyperglycemia but also other metabolic disorders of MDS, promoting an up-to-date management philosophy. In this review, we aim to summarize the underlying mechanism, screening, diagnosis, prevention, and treatment of T2D, especially regarding the personalized selection of hypoglycemic agents and holistic management based on the concept of "MDS-related TOD".

New labdane diterpenoids from Alpinia galanga: A new type of GLP-1 secretagogues targeting the PKA-CREB and PI3K-Akt signaling axes

Glucagon-like peptide-1 (GLP-1) secretagogues are fascinating pharmacotherapies to overcome the defects of GLP-1 analogs and dipeptidyl peptidase-4 (DPP-4) inhibitors in treating diabetes and obesity. To discover new GLP-1 secretagogues from natural sources, alpigalangols A-Q (1-17), 17 new labdane diterpenoids including four unusual nor-labdane and N-containing ones, were isolated from the fruits of Alpinia galanga. Most of the isolates showed GLP-1 promotive effects in NCl-H716 cells, of which compounds 3, 4, 12, and 14-17 were revealed with high promoting rates of 246.0%-413.8% at 50 µM. A mechanistic study manifested that the most effective compound 12 upregulated the mRNA expression of Gcg and Pcsk1, and the protein phosphorylation of PKA, CREB, and GSK3β, but was inactive on GPBAR and GPR119 receptors. Network pharmacology analysis indicated that the PI3K-Akt pathway was involved in the GLP-1 stimulation of 12, which was highly associated with AKT1, CASP3, PPARG, and ICAM1 proteins. This study suggests that A. galanga is rich in diverse labdane diterpenoids with GLP-1 promoting effects, representing a new type of antidiabetic candidates from natural sources.

Exploring the design of clinical research studies on the efficacy mechanisms in type 2 diabetes mellitus

This review examines the complexities of Type 2 Diabetes Mellitus (T2DM), focusing on the critical role of integrating omics technologies with traditional experimental methods. It underscores the advancements in understanding the genetic diversity of T2DM and emphasizes the evolution towards personalized treatment modalities. The paper analyzes a variety of omics approaches, including genomics, methylation, transcriptomics, proteomics, metabolomics, and intestinal microbiomics, delineating their substantial contributions to deciphering the multifaceted mechanisms underlying T2DM. Furthermore, the review highlights the indispensable role of non-omics experimental techniques in comprehending and managing T2DM, advocating for their integration in the development of tailored medicine and precision treatment strategies. By identifying existing research gaps and suggesting future research trajectories, the review underscores the necessity for a comprehensive, multidisciplinary approach. This approach synergistically combines clinical insights with cutting-edge biotechnologies, aiming to refine the management and therapeutic interventions of T2DM, and ultimately enhancing patient outcomes. This synthesis of knowledge and methodologies paves the way for innovative advancements in T2DM research, fostering a deeper understanding and more effective treatment of this complex condition.

The role and mechanism of VDAC1 in type 2 diabetes: An underestimated target of environmental pollutants

Type 2 diabetes (T2D) is a chronic metabolic disease that accounts for more than 90% of diabetic patients. Its main feature is hyperglycemia due to insulin resistance or insulin deficiency. With changes in diet and lifestyle habits, the incidence of T2D in adolescents has burst in recent decades. The deterioration in the exposure to the environmental pollutants further aggravates the prevalence of T2D, and consequently, it imposes a significant economic burden. Therefore, early prevention and symptomatic treatment are essential to prevent diabetic complications. Mitochondrial number and electron transport chain activity are decreased in the patients with T2D. Voltage-Dependent Anion Channel 1 (VDAC1), as a crucial channel protein on the outer membrane of mitochondria, regulates signal transduction between mitochondria and other cellular components, participating in various biological processes. When VDAC1 exists in oligomeric form, it additionally facilitates the entry and exit of macromolecules into and from mitochondria, modulating insulin secretion. We summarize and highlight the interplay between VDAC1 and T2D, especially in the environmental pollutants-related T2D, shed light on the potential therapeutic implications of targeting VDAC1 monomers and oligomers, providing a new possible target for the treatment of T2D.

Advances in small-molecule insulin secretagogues for diabetes treatment

Diabetes, a metabolic disease caused by abnormally high levels of blood glucose, has a high prevalence rate worldwide and causes a series of complications, including coronary heart disease, stroke, peripheral vascular disease, end-stage renal disease, and retinopathy. Small-molecule compounds have been developed as drugs for the treatment of diabetes because of their oral advantages. Insulin secretagogues are a class of small-molecule drugs used to treat diabetes, and include sulfonylureas, non-sulfonylureas, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase 4 inhibitors, and other novel small-molecule insulin secretagogues. However, many small-molecule compounds cause different side effects, posing huge challenges to drug monotherapy and drug selection. Therefore, the use of different small-molecule drugs must be improved. This article reviews the mechanism, advantages, limitations, and potential risks of small-molecule insulin secretagogues to provide future research directions on small-molecule drugs for the treatment of diabetes.

Hyperglycemia impairs EAAT2 glutamate transporter trafficking and glutamate clearance in islets of Langerhans: implications for type 2 diabetes pathogenesis and treatment

Pancreatic endocrine cells employ a sophisticated system of paracrine and autocrine signals to synchronize their activities, including glutamate, which controls hormone release and β-cell viability by acting on glutamate receptors expressed by endocrine cells. We here investigate whether alteration of the excitatory amino acid transporter 2 (EAAT2), the major glutamate clearance system in the islet, may occur in type 2 diabetes mellitus and contribute to β-cell dysfunction. Increased EAAT2 intracellular localization was evident in islets of Langerhans from T2DM subjects as compared with healthy control subjects, despite similar expression levels. Chronic treatment of islets from healthy donors with high-glucose concentrations led to the transporter internalization in vesicular compartments and reduced [H3]-d-glutamate uptake (65 ± 5% inhibition), phenocopying the findings in T2DM pancreatic sections. The transporter relocalization was associated with decreased Akt phosphorylation protein levels, suggesting an involvement of the phosphoinositide 3-kinase (PI3K)/Akt pathway in the process. In line with this, PI3K inhibition by a 100-µM LY294002 treatment in human and clonal β-cells caused the transporter relocalization in intracellular compartments and significantly reduced the glutamate uptake compared to control conditions, suggesting that hyperglycemia changes the trafficking of the transporter to the plasma membrane. Upregulation of the glutamate transporter upon treatment with the antibiotic ceftriaxone rescued hyperglycemia-induced β-cells dysfunction and death. Our data underscore the significance of EAAT2 in regulating islet physiology and provide a rationale for potential therapeutic targeting of this transporter to preserve β-cell survival and function in diabetes.NEW & NOTEWORTHY The glutamate transporter SLC1A2/excitatory amino acid transporter 2 (EAAT2) is expressed on the plasma membrane of pancreatic β-cells and controls islet glutamate clearance and β-cells survival. We found that the EAAT2 membrane expression is lost in the islets of Langerhans from type 2 diabetes mellitus (T2DM) patients due to hyperglycemia-induced downregulation of the phosphoinositide 3-kinase/Akt pathway and modification of its intracellular trafficking. Pharmacological rescue of EAAT2 expression prevents β-cell dysfunction and death, suggesting EAAT2 as a new potential target of intervention in T2DM.

Marine algae-derived oligosaccharide via protein crotonylation of key targeting for management of type 2 diabetes mellitus in the elderly

Global aging is a tendency of the world, as is the increasing prevalence of diabetes, and the two are closely linked. In our early research, Enteromorpha prolifera oligosaccharide (EPO) possesses the excellent ability of anti-oxidative, anti-inflammatory, and anti-diabetic. We aim to further explore the deeper mechanism of how EPO delays aging and regulates glycometabolism. EPO effectively impacts crotonylation procession to enhance glucose metabolism and reduce cell senescence in aging diabetic rats. Crotonylation modification of XPO1 influences the expression of critical genes, including p53, CDK1, and CCNB1, which affect cell cycle regulation and aging. Additionally, EPO improves glucose metabolism by inhibiting the crotonylation modification of HSPA8-K126 and activating the AKT pathway. EPO promotes crotonylation of histones in intestinal cells, influencing the aging process by increasing the butyric acid-producing bacteria Ruminococcaceae. The observed enhancement in pyrimidine metabolism underscores EPO's potential role in regulating intestinal health, presenting a promising avenue for delaying aging. In summary, our findings affirm EPO as a naturally bioactive ingredient with significant potential for anti-aging and antidiabetic interventions.

Appetite sensation improvement by synbiotic supplementation in patients with metabolic syndrome: A randomized controlled clinical trial

The potential link between dysbiosis, features of metabolic syndrome (MetS), inflammation, and sensation impairment has been recently recognized. However, in this context, there are few indications available regarding the effects of co-supplementation with Bacillus indicus, Bacillus coagulans, and fructooligosaccharide (FOS) prebiotics on patients with MetS. Therefore, this study aimed to investigate the effects of synbiotic supplementation on glycemic indices, inflammatory biomarkers, and appetite among adults with MetS. This study is a randomized, double-blind, placebo-controlled clinical trial conducted in the Endocrine and Metabolism Research Center outpatient clinic in Isfahan, Iran. Fifty-eight MetS patients were randomly assigned to receive either synbiotics (n = 29) or placebo (n = 29) supplementation twice per day for 8 weeks. Finally, 55 patients were recruited for analyses (28 in the intervention group and 27 in the placebo group). Random permuted blocks and a computer-generated random number table were used for treatment allocation. No adverse effects were reported during the study. There were no significant differences in glycemic indices and inflammatory markers within- and between groups (all p > .05). However, a significant increase in the sensation of fullness was documented in the synbiotic group. In conclusion, the eight-week treatment did not improve glycemic control and inflammatory markers. Nevertheless, it demonstrated potential efficacy in enhancing participants' appetite sensations, warranting further evaluation in longer intervention periods during future clinical trials.

Innovative peptide architectures: advancements in foldamers and stapled peptides for drug discovery

INTRODUCTION

Peptide foldamers play a critical role in pharmaceutical research and biomedical applications. This review highlights recent (post-2020) advancements in novel foldamers, synthetic techniques, and their applications in pharmaceutical research.

AREAS COVERED

The authors summarize the structures and applications of peptide foldamers such as α, β, γ-peptides, hydrocarbon-stapled peptides, urea-type foldamers, sulfonic-γ-amino acid foldamers, aromatic foldamers, and peptoids, which tackle the challenges of traditional peptide drugs. Regarding antimicrobial use, foldamers have shown progress in their potential against drug-resistant bacteria. In drug development, peptide foldamers have been used as drug delivery systems (DDS) and protein-protein interaction (PPI) inhibitors.

EXPERT OPINION

These structures exhibit resistance to enzymatic degradation, are promising for therapeutic delivery, and disrupt crucial PPIs associated with diseases such as cancer with specificity, versatility, and stability, which are useful therapeutic properties. However, the complexity and cost of their synthesis, along with the necessity for thorough safety and efficacy assessments, necessitate extensive research and cross-sector collaboration. Advances in synthesis methods, computational modeling, and targeted delivery systems are essential for fully realizing the therapeutic potential of foldamers and integrating them into mainstream medical treatments.

Efficacy and safety of visepegenatide, a long-acting weekly GLP-1 receptor agonist as monotherapy in type 2 diabetes mellitus: a randomised, double-blind, parallel, placebo-controlled phase 3 trial

BACKGROUND

Type 2 diabetes (T2DM) remains a challenge to treat despite the expansion of various therapeutic classes. Visepegenatide (PB-119) is a once a week, subcutaneous, glucagon-like peptide-1 receptor agonist (GLP-1 RA) injection without the requirement of dose titration that has shown glycaemic control and safety profile in two phase 2 studies conducted in China and the United States, respectively. The aim of this study was to evaluate the efficacy and safety of visepegenatide as a monotherapy in treatment-naïve patients with T2DM.

METHODS

This was a multicentre, double-blind, parallel, placebo-controlled, phase 3 trial conducted in 30 centres in China. Adult participants (aged 18-75 years) with T2DM, glycated haemoglobin (HbA1c) of 7.5%-11.0% [58.47-96.73 mmol/mol], body mass index (BMI) of 18-40 kg/m2, and who had been treated with diet and exercise alone for at least 8 weeks before the screening visit were eligible for enrolment. After a 4-week placebo injection run-in period, participants with HbA1c of 7.0%-10.5% [53.0-91.3 mmol/mol] and fasting plasma glucose (FPG) < 15 mmol/L were randomised in a ratio of 1:1 to receive visepegenatide (150 μg) or placebo subcutaneous injections once a week for 24 weeks. The treatment was extended to another 28 weeks during which all participants received visepegenatide. The primary outcome was a change in HbA1c from baseline to week 24. This study was registered with ClinicalTrials.gov, as NCT04504370.

FINDINGS

Between November 2, 2020, and November 2, 2022, we randomly assigned 273 adult participants to the visepegenatide (n = 137) and placebo (n = 136) groups. In total, 257 (94.12%) participants, 131 (95.6%) on visepegenatide, and 126 (92.6%) on placebo, completed the double-blinded treatment period. At baseline, the mean (SD) HbA1c was 8.47% (0.81) [69.07 [8.81] mmol/mol], which rapidly decreased to 7.63% (0.80) [59.94 [8.70] mmol/mol] with visepegenatide by week 4 of treatment, and the change from baseline was significantly greater than that in the placebo group (-0.82% [-0.90 to -0.74]; [-8.99 [-9.89 to -8.10] mmol/mol] vs -0.30% [-0.41 to -0.19]; [-3.30 [-4.50 to -2.09] mmol/mol]). At week 24, when evaluating the effects of treatment with treatment policy estimand, the least square mean (LSM change in HbA1c from baseline was -1.36 (95% confidence interval [CI] -1.52 to -1.20) [-14.84 [-16.60 to -13.08] mmol/mol] in the visepegenatide group vs -0.63 (-0.79 to -0.46) [-6.84 [-8.61 to -5.07] mmol/mol] in the placebo group. The reduction in HbA1c was significantly greater with visepegenatide than placebo (LSM difference -0.73, 95% CI -0.96 to -0.50; p < 0.001). When evaluating the treatment estimand with hypothetic policy, the LSM change in HbA1c from baseline in the visepegenatide group (-1.37 [-1.53 to -1.20]) [-14.95 [-16.76 to -13.14] mmol/mol] was significantly greater than the placebo group (-0.63 [-0.81 to -0.45]) [6.90 (-8.89 to -4.90) mmol/mol]. The LSM difference was (-0.74, 95% CI -0.98 to -0.49; [-8.00 [-10.50 to -5.50] mmol/mol]; p < 0.001]. A significantly greater proportion of the visepegenatide group achieved a target HbA1c level of <7% (<53 mmol/mol) than the placebo (50.4% vs 14.2%; p < 0.05) and stringent HbA1c level of ≤6.5% (≤48 mmol/mol) (26.7% vs 7.9%), respectively. There was also a significantly greater improvement in FPG, 2-h postprandial glucose, homeostasis model assessment (HOMA) of beta cell function, post-prandial insulin, fasting, and post-prandial C-peptide level (p < 0.05) with visepegenatide treatment. The number (3 [2.2%]) of participants who received rescue therapy in the visepegenatide group was remarkably lower compared with those (17 [12.5%]) in the placebo group (p < 0.05). During the extended treatment period, visepegenatide consistently maintained the efficacy till week 52 confirmed by all the above endpoints. The reduction in HbA1c at week 52 was -1.39% (-1.58 to -1.19) [-15.14 [-17.28 to -13.01] mmol/mol], which was even greater than that at week 24. There was also a significant improvement in HOMA-insulin resistance (p = 0.004) at week 52 compared with the baseline value. For the placebo→visepegenatide group, which received visepegenatide in the extended treatment period, a notable decrease in HbA1c at week 52 compared to baseline was observed. The change from baseline in HbA1c was -1.49% (-1.68 to -1.30) [-16.27 [-18.37 to -14.16] mmol/mol]. The outcome was in the same direction as the visepegenatide group from the double-blind treatment period. Comprehensive benefits of visepegenatide including weight loss, improvement in lipid profile, and reduction in blood pressure have been demonstrated in this study. Visepegenatide reduced the body weight in a BMI-dependent manner that was prominent in BMI ˃32 kg/m2 with a mean (SD) reduction of -4.77 (13.94) kg at week 52 (p < 0.05). Incidences of gastrointestinal adverse events were less common than other weekly GLP-1 RA in the market, and most of the adverse events were mild and moderate in nature, occurring in the first weeks of the treatment, and were transient. No serious hypoglycaemia or grade 2 hypoglycaemia (blood glucose: ≤3 mmol/L) was reported during the study.

INTERPRETATION

As a monotherapy, visepegenatide provided rapid without the risk of hypoglycaemia, significant, and sustainable glycaemic control by improving islet β-cell function and insulin resistance. Treatment with visepegenatide induced early treatment response in reducing HbA1c and maintaining glycaemic control for 52 weeks. Meanwhile, visepegenatide provided a comprehensive benefit in body weight loss, lipids, and blood pressure reduction. Visepegenatide had a better safety profile than other weekly GLP-1 RA in participants with T2DM even without the requirement of dose titration. Visepegenatide would provide an optimal treatment approach with its high benefit and low-risk balance.

FUNDING

PegBio Co., Ltd.

Multiple nanotechnological approaches using natural compounds for diabetes management

Objectives

Diabetes mellitus (DM) is a long-standing and non-transmissible endocrine disease that generates significant clinical issues and currently affects approximately 400 million people worldwide. The aim of the present review was to analyze the most relevant and recent studies that focused on the potential application of plant extracts and phytocompounds in nanotechnology for the treatment of T2DM.

Methods

Various databases were examined, including Springer Link, Google Scholar, PubMed, Wiley Online Library, and Science Direct. The search focused on discovering the potential application of nanoparticulate technologies in enhancing drug delivery of phytocompounds for the mentioned condition.

Results

Several drug delivery systems have been considered, that aimed to reduce adverse effects, while enhancing the efficiency of oral antidiabetic medications. Plant-based nanoformulations have been highlighted as an innovative approach for DM treatment due to their eco-friendly and cost-effective synthesis methods. Their benefits include targeted action, enhanced availability, stability, and reduced dosage frequency.

Conclusions

Nanomedicine has opened new opportunities for the diagnosis, treatment, and prevention of DM. The use of nanomaterials has demonstrated improved outcomes for both T1DM and T2DM. Notably, flavonoids, including substances such as quercetin, naringenin and myricitrin, have been recognized for their enhanced efficacy when delivered through novel nanotechnologies in preventing T2DM onset and associated complications. The perspectives on the addressed subject point to the development of more nanostructured phytocompounds with improved bioavailability and therapeutic efficacy.

Exploring the mechanism of Jinlida granules against type 2 diabetes mellitus by an integrative pharmacology strategy

Jinlida granule (JLD) is a Traditional Chinese Medicine (TCM) formula used for the treatment of type 2 diabetes mellitus (T2DM). However, the mechanism of JLD treatment for T2DM is not fully revealed. In this study, we explored the mechanism of JLD against T2DM by an integrative pharmacology strategy. Active components and corresponding targets were retrieved from Traditional Chinese Medicine System Pharmacology (TCMSP), SwissADME and Bioinformatics Analysis Tool for Molecular Mechanisms of Traditional Chinese Medicine Database (BATMAN-TCM) database. T2DM-related targets were obtained from Drugbank and Genecards databases. The protein-protein interaction (PPI) network was constructed and analyzed with STRING (Search Toll for the Retrieval of Interacting Genes/proteins) and Cytoscape to get the key targets. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) enrichment analyses were performed with the Database for Annotation, Visualization and Integrated Discovery (DAVID). Lastly, the binding capacities and reliability between potential active components and the targets were verified with molecular docking and molecular dynamics simulation. In total, 185 active components and 337 targets of JLD were obtained. 317 targets overlapped with T2DM-related targets. RAC-alpha serine/threonine-protein kinase (AKT1), tumor necrosis factor (TNF), interleukin-6 (IL-6), cellular tumor antigen p53 (TP53), prostaglandin G/H synthase 2 (PTGS2), Caspase-3 (CASP3) and signal transducer and activator of transcription 3 (STAT3) were identified as seven key targets by the topological analysis of the PPI network. GO and KEGG enrichment analyses showed that the effects were primarily associated with gene expression, signal transduction, apoptosis and inflammation. The pathways were mainly enriched in PI3K-AKT signaling pathway and AGE-RAGE signaling pathway in diabetic complications. Molecular docking and molecular dynamics simulation verified the good binding affinity between the key components and targets. The predicted results may provide a theoretical basis for drug screening of JLD and a new insight for the therapeutic effect of JLD on T2DM.

Thiazolidinediones Decrease the Recurrence of Intracerebral Hemorrhage in Type 2 Diabetes Mellitus Patients: A Nested Case-Control Study

INTRODUCTION

Preclinical evidence demonstrated the therapeutic potential of thiazolidinediones (TZDs) for the treatment of intracerebral hemorrhage (ICH). The present study conducted an investigation of cerebrovascular and cardiovascular outcomes following ICH in patients with type 2 diabetes mellitus (T2DM) treated with or without TZDs.

METHODS

This retrospective nested case-control study used data from the Taiwan National Health Insurance Research Database. A total of 62,515 T2DM patients who were hospitalized with a diagnosis of ICH were enrolled, including 7,603 TZD users. Data for TZD non-users were extracted using propensity score matching. Primary outcomes included death and major adverse cardiovascular events (MACEs), which were defined as a composite of ischemic stroke, hemorrhagic stroke (HS), acute myocardial infarction, and congestive heart failure. Patients aged <20 years with a history of traumatic brain injury or any prior history of MACEs were excluded.

RESULTS

TZD users had significantly lower MACE risks compared with TZD non-users following ICH (adjusted hazard ratio [aHR]: 0.90, 95% confidence interval [CI]: 0.85-0.94, p < 0.001). The most significant MACE difference reported for TZD users was HS, which possessed lower incidence than in TZD non-users, especially for the events that happened within 3 months following ICH (aHR: 0.74, 95% CI: 0.62-0.89 within 1 month, p < 0.01; aHR: 0.68, 95% CI: 0.54-0.85 between 1 and 3 month).

CONCLUSION

The use of TZD in patients with T2DM was associated with a lower risk of subsequent HS and mortality following ICH.

The polysaccharides from seeds of Glycyrrhiza uralensis ameliorate metabolic disorders and restructure gut microbiota in type 2 diabetic mice

T2D and its complications are significant threats to human health and are among the most concerning metabolic diseases worldwide. Previous studies have revealed that Glycyrrhiza uralensis polysaccharide extract (GUP) exhibits remarkable antioxidant capabilities and inhibits alpha-glucosidase activity. However, whether GUP improves glycemic control in T2D is unknown. This study aims to investigate the effects of GUP on glucose and lipid metabolism as well as the intestinal microbiota in HFD/STZ-induced T2D. The results demonstrated that GUP could significantly ameliorate hyperglycemia, insulin resistance, oxidative stress, and reduce liver lipid levels in T2D mice. Furthermore, it also enhanced the integrity of the intestinal barrier in T2D mice by reducing the levels of pro-inflammatory cytokines and serum LPS levels. Interestingly, GUP treatment significantly lowered serum creatinine and urea nitrogen levels, mitigating renal function deterioration and interstitial fibrosis. Additionally, GUP intervention increased the α diversity of gut microbiota, promoting beneficial species like Akkermansia, Lactobacillus, Romboutsia and Faecalibaculum, while decreasing harmful ones such as Bacteroides, Escherichia-Shigella, and Clostridium sensu stricto 1 in T2D mice. Overall, this study highlights the potential of GUP in alleviating complications and enhancing intestinal health in T2D mice, providing valuable insights into dietary strategies for diabetes control and overall health improvement.

Preoperative Patient Evaluation: Newer Hypoglycemic Agents

New medications in the treatment of diabetes are an active area of research and drug development. Although many hypoglycemic therapies have been in use for decades, new evidence continues to emerge highlighting benefits of these medications for other indications. In this article, the authors review the classes of newer hypoglycemic agents and summarize medications currently in phase 2 and 3 clinical trials. The literature to support specific recommendations for perioperative management is scant, however, where it exists, we have included it. In other instances, the authors have noted a reasonable approach based on pharmacokinetics and principles of perioperative medication management.

Association of Antidiabetic Drug Target Genes with Inflammatory Bowel Disease: A Mendelian Randomization Study

Background

An unmet medical need for the treatment of inflammatory bowel disease (IBD) exists. A part of antidiabetic drugs had potential effects on IBD in various observational research.

Objective

To investigate the potential of antidiabetic drugs on IBD.

Methods

We undertook a summary-data-based Mendelian randomization (SMR) using the expression quantitative trait loci (eQTL) expressed in the blood or colon and a two sample Mendelian randomization (TSMR) utilizing single nucleotide polymorphism (SNP) of antidiabetic drug target genes mediated by blood glucose traits. Participants encompassed patients with IBD (25,042 cases/34,915 controls), UC (12,366 cases/33,609 controls), and CD (12,194 cases/28,072 controls). Data on eQTL in the blood or the colon were from the eQTLGen consortium (31,684 individuals) or GTEx Consortium V8, respectively. SMR was performed by SMR software (20,220,322); the primary method for TSMR was inverse-variance weighted (IVW) or Wald ratio through R studio (2023.06.0+421). Sensitivity analyses were carried out.

Results

A 1-SD upper expression of the KCNJ11 gene (target gene of sulfonylureas) in the blood reduced the risk of CD (OR per 1-SD = 0.728, 95% CI = 0.586-0.903, P = 0.004) according to the result of SMR. ABCC8 (target gene of sulfonylureas) expressed in the colon did not affect CD, UC, or IBD. T2D-mediated KCNJ11 has a protective effect on CD (OR = 0.475, 95% CI = 0.297-0.761, P = 0.002). Gene predicted no relationship between T2D and CD.

Conclusion

Sulfonylureas (SUs) may have side effects on CD. This work provides some suggestions for the selection of antidiabetic drugs in patients with CD.

A Hybrid Model of In-Person and Telemedicine Diabetes Education and Care for Management of Patients with Uncontrolled Type 2 Diabetes Mellitus: Findings and Implications from a Multicenter Prospective Study

Background

Patients with uncontrolled type 2 diabetes mellitus (T2DM) require close follow-up, support, and education to achieve glycemic control, especially during the initiation or intensification of insulin therapy and self-care management. This study aimed to describe and evaluate the impact of implementing a hybrid model of in-person and telemedicine care and education on glycemic control for patients with uncontrolled T2DM (hemoglobin A1c [HbA1c] ≥9%) during the coronavirus disease pandemic.

Methods

This prospective multicenter-cohort pre-/post-intervention study was conducted on patients with uncontrolled T2DM. This study included three chronic illness centers affiliated with the Family and Community Medicine Department at Prince Sultan Military Medical City in Riyadh, Saudi Arabia. A hybrid model of in-person (onsite) and telemedicine care and education was developed. This involved implementing initial in-person care at the physicians' clinic and initial in-person education at the diabetes education clinic, followed by telemedicine services of tele-follow-ups, support, and education for an average 4-month follow-up period.

Results

Of the enrolled 181 patients, more than half of the participants were women (n = 103, 56.9%). The mean age of participants (standard deviation) was 58.64 ± 11.23 years and the mean duration of diabetes mellitus was 13.80 ± 8.55 years. The majority of the patients (n = 144; 79.6%) were on insulin therapy. Overall, in all three centers, the hybrid model had significantly reduced HbA1c from 10.47 ± 1.23% to 7.87 ± 1.59% (mean difference of reduction 2.59% [95% confidence interval (CI) = 2.34-2.85%], p < 0.001). At the level of each center, HbA1c was reduced significantly with mean differences of 3.17% (95% CI = 2.81-3.53%), 2.49% (95% CI = 1.92-3.06%), and 2.16% (95% CI = 1.76-2.57%) at centers A, B, and C, respectively (all p < 0.001).

Conclusion

The findings showed that the hybrid model of in-person and telemedicine care and education effectively managed uncontrolled T2DM. Consequently, the role of telemedicine in diabetes management could be further expanded as part of routine diabetes care in primary settings to achieve better glycemic control and minimize nonessential in-person visits when appropriate.

Probiotic co-supplementation with absorbent smectite for pancreatic beta-cell function in type 2 diabetes: a secondary-data analysis of a randomized double-blind controlled trials

Introduction

There is growing evidence from animal and clinical studies suggesting probiotics can positively affect type 2 diabetes (T2D). In a previous randomized clinical study, we found that administering a live multistrain probiotic and absorbent smectite once a day for eight weeks to patients with T2D could reduce chronic systemic inflammatory state, insulin resistance, waist circumference and improve the glycemic profile. However, there is a lack of evidence supporting the efficacy of probiotic co-supplementation with absorbent smectite on pancreatic β-cell function in T2D.

Aim

This secondary analysis aimed to assess the effectiveness of an alive multistrain probiotic co-supplementation with absorbent smectite vs placebo on β-cell function in T2D patients.

Material and methods

We performed a secondary analysis on a previously published randomized controlled trial (NCT04293731, NCT03614039) involving 46 patients with T2D. The main inclusion criteria were the presence of β-cell dysfunction (%B<60%) and insulin therapy alone or combined with oral anti-diabetic drugs. The primary outcome was assessing β-cell function as change C-peptide and %B.

Results

We observed only a tendency for improving β-cell function (44.22 ± 12.80 vs 55.69 ± 25.75; р=0.094). The effectiveness of the therapy probiotic-smectite group was confirmed by fasting glycemia decreased by 14% (p=0.019), HbA1c - 5% (p=0.007), HOMA-2 - 17% (p=0.003) and increase of insulin sensitivity by 23% (p=0.005). Analysis of the cytokine profile showed that statistical differences after treatment were in the concentration of both pro-inflammatory cytokines: IL-1β (22.83 ± 9.04 vs 19.03 ± 5.57; p=0.045) and TNF-α (31.25 ± 11.32 vs 26.23 ± 10.13; p=0.041).

Conclusion

Adding a live multistrain probiotic and absorbent smectite supplement slightly improved β-cell function and reduced glycemic-related parameters in patients with T2D. This suggests that adjusting the gut microbiota could be a promising treatment for diabetes and warrants further investigation through more extensive studies.

Revealing the improvement of diabetes by Si Wei Jiang Huang Tang San through ERK/HIF1α signaling pathway via network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Si Wei Jiang Huang Tang San (SWJHTS) is a traditional Tibetan medicine prescription for the treatment of urethritis, frequent urination, and urgency, composed of four traditional Chinese medicines: Curcumae longae rhizoma, Berberidis cortex, Tribuli fructus, and Phyllanthi fructus. However, whether SWJHTS exhibits hypoglycemic efficacy and its specific mechanism remain unclear.

AIM OF THE STUDY

In this study, we aimed to investigate the anti-diabetic effects of SWJHTS and elucidate the underlying mechanism.

MATERIALS AND METHODS

HPLC-MS method was used to identify the key components of four kinds of traditional Chinese medicine (Curcumae longae rhizoma, Berberidis cortex., Tribuli fructus, and Phyllanthi fructus) which composed SWJHTS and determine their structure. Normal mice and 145 mg/kg STZ-induced type 1 diabetic mice were treated with three doses of SWJTHS by oral gavage. Body weight, 24h food and water intake, fasting blood glucose, glucose tolerance and other indicators were measured to evaluate the hypoglycemic effect of SWJHTS. OMIM, Genecards and other databases were used to collect targets of diabetes, and HPLC-MS results and TCMSP database information were used to collect drug component targets. Bioinformatics methods such as pathway enrichment analysis and molecular docking were used to predict the key targets of SWJHTS. The gene and protein expressions of HIF1α and ERK signaling pathways in HepG2 cells treated with SWJHTS were detected by RT-PCR and Western blot.

RESULTS

A total of 181 components were identified, including curcumin, palmatine, and berberine, etc. The in vivo studies showed that SWJHTS could significantly lower fasting blood glucose levels and improve the symptoms of polydipsia, polyphagia, and polyuria in diabetic mice. Furthermore, we identified HIF1α as the potential key target of SWJHTS against diabetes utilizing network pharmacology approach and in silico molecular docking. Subsequently, we experimentally confirmed that SWJHTS could suppress the high glucose-induced upregulation of HIF1α expression, which mediated the glucose consumption in HepG2 cells. The ERK signaling pathway was further found to be activated by the SWJHTS as the upstream of HIF1α.

CONCLUSIONS

SWJHTS can improve glucose metabolism by targeting the ERK/HIF1α signaling pathway; hence might be a prospective anti-diabetic drug for diabetic patients as traditional Tibetan medicine.

Amylin, Another Important Neuroendocrine Hormone for the Treatment of Diabesity

Diabetes mellitus is a devastating chronic metabolic disease. Since the majority of type 2 diabetes mellitus patients are overweight or obese, a novel term-diabesity-has emerged. The gut-brain axis plays a critical function in maintaining glucose and energy homeostasis and involves a variety of peptides. Amylin is a neuroendocrine anorexigenic polypeptide hormone, which is co-secreted with insulin from β-cells of the pancreas in response to food consumption. Aside from its effect on glucose homeostasis, amylin inhibits homeostatic and hedonic feeding, induces satiety, and decreases body weight. In this narrative review, we summarized the current evidence and ongoing studies on the mechanism of action, clinical pharmacology, and applications of amylin and its analogs, pramlintide and cagrilintide, in the field of diabetology, endocrinology, and metabolism disorders, such as obesity.

Novel Activity of Oral Hypoglycemic Agents Linked with Decreased Formation of Tryptophan Metabolite, Kynurenic Acid

Kynurenic acid is a tryptophan (Trp) metabolite formed along the kynurenine (KYN) pathway in the brain and in peripheral tissues. The disturbed formation of kynurenic acid, which targets glutamate-mediated neurotransmission, GPR35, and aryl hydrocarbon receptors of immune or redox status, was implicated in the development of neuropsychiatric and metabolic disorders among others. Kynurenic acid exerts neuroprotective and immunomodulatory effects, yet its high brain levels may negatively impact cognition. Changes in the Trp-KYN pathway are also linked with the pathogenesis of diabetes mellitus, which is an established risk factor for cardiovascular and neurological diseases or cognitive deficits. Here, the effects of metformin and glibenclamide on the brain synthesis of kynurenic acid were evaluated. Acute exposure of rat cortical slices in vitro to either of the drugs reduced kynurenic acid production de novo. Glibenclamide, but not metformin, inhibited the activity of kynurenic acid biosynthetic enzymes, kynurenine aminotransferases (KATs) I and II, in semi-purified cortical homogenates. The reduced availability of kynurenic acid may be regarded as an unwanted effect, possibly alleviating the neuroprotective action of oral hypoglycemic agents. On the other hand, considering that both compounds ameliorate the cognitive deficits in animal and human studies and that high brain kynurenic acid may hamper learning and memory, its diminished synthesis may improve cognition.

Plasma proteome profiling reveals the therapeutic effects of the PPAR pan-agonist chiglitazar on insulin sensitivity, lipid metabolism, and inflammation in type 2 diabetes

Chiglitazar is a novel peroxisome proliferator-activated receptor (PPAR) pan-agonist, which passed phase III clinical trials and was newly approved in China for use as an adjunct to diet and exercise in glycemic control in adult patients with Type 2 Diabetes (T2D). To explore the circulating protein signatures associated with the administration of chiglitazar in T2D patients, we conducted a comparative longitudinal study using plasma proteome profiling. Of the 157 T2D patients included in the study, we administered chiglitazar to a specific group, while the controls were given either placebo or sitagliptin. The plasma proteomes were profiled at baseline and 12 and 24 weeks post-treatment using data-independent acquisition mass spectrometry (DIA-MS). Our study indicated that 13 proteins were associated with chiglitazar treatment in T2D patients, including 10 up-regulated proteins (SHBG, TF, APOA2, APOD, GSN, MBL2, CFD, PGLYRP2, A2M, and APOA1) and 3 down-regulated proteins (PRG4, FETUB, and C2) after treatment, which were implicated in the regulation of insulin sensitivity, lipid metabolism, and inflammation response. Our study provides insight into the response of chiglitazar treatment from a proteome perspective and demonstrates the multi-faceted effects of chiglitazar in T2D patients, which will help the clinical application of chiglitazar and further study of its action mechanism.