Activation of AMPK/SIRT1/FOXO3a signaling by BMS-477118 (saxagliptin) mitigates chronic colitis in rats: uncovering new anti-inflammatory and antifibrotic roles.

Ulcerative colitis (UC) is a debilitating chronic disease marked by persistent inflammation and intestinal fibrosis. Despite the availability of various treatments, many patients fail to achieve long-term remission, underscoring a significant unmet therapeutic need. BMS-477118, a reversible inhibitor of dipeptidyl peptidase 4 (DPP4), has demonstrated anti-inflammatory properties in preclinical and clinical studies with minimal adverse effects compared to other antidiabetic agents. However, the potential benefits of BMS-477118 in chronic UC have not yet been explored. In this study, we aimed to investigate the effects of BMS-477118 in rats subjected to chronic dextran sodium sulfate (DSS) administration. Our findings indicate that BMS-477118 activates the interconnected positive feedback loop involving AMPK, SIRT1, and FOXO3a, improving histological appearance in injured rat colons. BMS-477118 also reduced fibrotic changes associated with the chronic nature of the animal model, alleviated macroscopic damage and disease severity, and improved the colon weight-to-length ratio. Additionally, BMS-477118 prevented DSS-induced weight loss and enhanced tight junction proteins. These effects, in conjunction with reduced oxidative stress and its potential anti-inflammatory, antiapoptotic, and autophagy-inducing properties, fostered prolonged survival in rats with chronic UC. To conclude, BMS-477118 has the potential to activate the AMPK/SIRT1/FOXO3a signaling pathway in inflamed colons. These results suggest that the AMPK/SIRT1/FOXO3a pathway could be a new therapeutic target for UC. Further research is mandatory to explore the therapeutic possibilities of this pathway. Additionally, continued studies on the therapeutic potential of BMS-477118 and other DPP4 inhibitors are promising for creating new treatments for various conditions, including UC in diabetic patients.

Vitamin D3 mitigates myopathy and metabolic dysfunction in rats with metabolic syndrome: the potential role of dipeptidyl peptidase-4.

Metabolic syndrome is associated with vitamin D3 deficiency. This work aims to examine the efficacy of vitamin D3 in inhibiting MetS-induced myopathy and to determine whether the beneficial effects of vitamin D3 are mediated by the inhibition of dipeptidyl peptidase-4 (DPP-4). An in silico study investigated the potential effectiveness of vitamin D3 on the inhibition of the DPP-4 enzyme. An in vitro assay of the DPP-4 inhibitory effect of vitamin D3 was performed. In vivo and over 12 weeks, both diet (with 3% salt) and drinking water (with 10% fructose) were utilized to induce MetS. In the seventh week, rats received either vitamin D3, vildagliptin, a combination of both, or vehicles. Serum lipids, adipokines, glycemic indices, and glucagon-like peptide-1 (GLP-1), muscular glucose transporter type-4 (GLUT-4) content, DPP-4, adenosine monophosphate kinase (AMPK) activities, and Sudan Black B-stained lipids were assessed. Muscular reactive oxygen species (ROS), caspase-3, and desmin immunostaining were used to determine myopathy. MetS-induced metabolic dysfunction was ameliorated by vitamin D3, which also reduced intramuscular glycogen and lipid accumulation. This is demonstrated by the attenuation of MetS-induced myopathy by vitamin D3, decreased oxidative stress, increased desmin immuno-expression, and caspase-3 activity. Our in silico data demonstrated that vitamin D3 is capable of inhibiting DPP-4, which is further supported by biochemical findings. Vitamin D3 increased serum GLP-1, muscular AMPK activity, and GLUT-4 content, whereas the levels of muscular ROS were decreased in MetS. Vildagliptin and its combination with vitamin D3 yielded comparable results. It is suggested that the DPP-4 inhibitory potential of vitamin D3 is responsible for the amelioration of MetS-induced metabolic changes and myopathy.

Causal relationship between novel antidiabetic drugs and ischemic stroke: a drug-targeted Mendelian randomization study.

Background: The escalating global economic burden of ischemic stroke poses a significant public health challenge amid global aging trends. The broad therapeutic efficacy of new antidiabetic drugs may offer new options in the prevention and treatment of ischemic stroke. Consistent conclusions regarding the relationship between novel antidiabetic agents and the risk of ischemic stroke remain elusive, and the causal relationship deserves further investigation. Materials and methods: Three novel antidiabetic drug targets were selected, and cis-expression quantitative trait loci (cis-eQTL) were screened as instrumental variables. Genetic association data for ischemic stroke were obtained from the Genome-wide Association Study (GWAS) database. Mendelian randomization (MR) analysis, facilitated by R software, calculated MR estimates for each single nucleotide polymorphism (SNP), and meta-analysis was performed using five methods. To ensure robustness, sensitivity analyses, heterogeneity analyses, horizontal pleiotropy analyses, and co-localization analyses were conducted for significant MR associations. Results: Three eQTLs for antidiabetic drug genes served as instrumental variables, utilizing a GWAS dataset comprising 34,217 cases and 406,111 controls for ischemic stroke. Genetic variants in glucagon-like peptide-1 receptor agonists (GLP-1 RA) targets exhibited a positive correlation with ischemic stroke risk (OR 1.06, 95% CI 1.04-1.08, P = 0.000), while genetic variation in dipeptidyl peptidase 4 inhibitors (DPP-4i) targets showed a negative association with ischemic stroke risk (OR 0.93, 95% CI 0.89-0.97, P = 0.003). Sensitivity analyses supported robust conclusions, revealing no heterogeneity or horizontal pleiotropy. Conclusion: This study found that GLP-1 RA and DPP-4i were associated with an increased risk of ischemic stroke by MR analysis. Although sensitivity analyses provide support for this result, it contradicts previous knowledge. Therefore, the results of this study still need to treated with caution. Updated and more in-depth GWAS data and high-quality real-world data are expected to validate the results.

Single-cell transcriptome analysis of the mouse lungs during the injury and recovery periods after lipopolysaccharide administration.

OBJECTIVE: This study sought to investigate the cellular and molecular alterations during the injury and recovery periods of ALI and develop effective treatments for ALI. METHODS: Pulmonary histology at 1, 3, 6, and 9 days after lipopolysaccharide administration mice were assessed. An unbiased single-cell RNA sequencing was performed in alveoli tissues from injury (day 3) and recovery (day 6) mice after lipopolysaccharide administration. The roles of Fpr2 and Dpp4 in ALI were assessed. RESULTS: The most severe lung injury occurred on day 3, followed by recovery entirely on day 9 after lipopolysaccharide administration. The numbers of Il1a+ neutrophils, monocytes/macrophages, and Cd4+ and Cd8+ T cells significantly increased at day 3 after LPS administration; subsequently, the number of Il1a+ neutrophils greatly decreased, the numbers of monocytes/macrophages and Cd4+ and Cd8+ T cells continuously increased, and the number of resident alveolar macrophages significantly increased at day 6. The interactions between monocytes/macrophages and pneumocytes during the injury period were enhanced by the Cxcl10/Dpp4 pair, and inhibiting Dpp4 improved ALI significantly, while inhibiting Fpr2 did not. CONCLUSIONS: Our results offer valuable insights into the cellular and molecular mechanisms underlying its progression and identify Dpp4 as an effective therapeutic target for ALI.

SOX9 promotes hypoxic pulmonary hypertension through stabilization of DPP4 in pulmonary artery smooth muscle cells.

Pulmonary hypertension (PH) is a progressive cardiopulmonary disorder characterized by pulmonary vascular remodeling (PVR), primarily due to the excessive proliferation of pulmonary artery smooth muscle cells (PASMCs). This study aimed to investigate the role and molecular mechanism of SOX9 in hypoxic PH in rats. The findings revealed that SOX9 was upregulated in the pulmonary arteries and PASMCs of hypoxia-exposed rats. SOX9 knockdown inhibited hypoxia-induced proliferation and migration of PASMCs, reduced PVR, and subsequently alleviated hypoxia-induced PH in rats, suggesting that SOX9 plays a critical role in PH. Further investigation demonstrated that SOX9 interacted with DPP4, preventing its ubiquitin degradation in hypoxia-exposed PASMCs. DPP4 knockdown inhibited hypoxia-induced PASMC proliferation and migration, and administration of the DPP4 inhibitor sitagliptin (5 mg/kg) significantly reduced PVR and alleviated hypoxia-induced PH in rats, indicating that SOX9 contributes to PH by stabilizing DPP4. The results also showed that hypoxia induced YAP1 expression and dephosphorylation, leading to YAP1 nuclear localization. YAP1 knockdown promoted the degradation of HIF-1α in hypoxia-exposed PASMCs and inhibited hypoxia-induced proliferation and migration of PASMCs. Additionally, HIF-1α, as a transcription factor, promoted SOX9 expression by binding to the SOX9 promoter in hypoxia-exposed PASMCs. In conclusion, hypoxia promotes the proliferation and migration of PASMCs through the regulation of the YAP1/HIF-1α/SOX9/DPP4 signaling pathway, leading to PH in rats. These findings suggest that SOX9 may serve as a potential prognostic marker and therapeutic target for PH.

Sex-specific Cardiovascular Risk Factors and Treatment in Females with T2DM and CVD: Developments and Knowledge Gaps.

PURPOSE: There are large disparities in the impact of diabetes on cardiovascular disease (CVD) risk and outcomes by sex and gender. Achieving health equity requires understanding risks and medication efficacy in female patients, especially now, as novel pharmacologic treatments are transforming the diabetes and CVD treatment landscape. This review examines two bodies of research that can inform sex differences in CVD in patients with diabetes: female-specific risk factors for CVD and sex-related limitations of clinical trial research in evaluating novel diabetes and CVD treatments. METHODS: Two literature searches were performed using Ovid Medline(R) All. The first retrieved manuscripts covering sex and gender differences related to CVD risk and therapies and diabetes. The second focused on randomized controlled trial data on sex/gender differences and GLP-1/SGLT-2/DPP-4 drugs. RESULTS: Female-specific risk factors for CVD include early menarche, premature or early menopause, irregular cycles and polycystic ovary syndrome (PCOS); pregnancy; adverse pregnancy outcomes; history of breast cancer; and autoimmune diseases. Clinical trials of novel pharmacological treatments for diabetes and CVD have undersampled female populations, and clinical characteristics of male and female participants have differed significantly. Thus, evidence to evaluate potential sex differences in treatment efficacy and side effects has been lacking. CONCLUSION: To improve health of female patients with diabetes, sex-specific cardiovascular risk factors should be taken into account in screening and treatment decisions. Further, studies of cardiovascular and diabetes medications must ensure adequate representation by sex and report participant characteristics and outcomes by sex.

Commentary on "Structural characterization of SLYM - a 4th meningeal membrane".

For centuries, the meninges have been described as three membranes: the inner pia, middle arachnoid and outer dura. It was therefore sensational when in early 2023 Science magazine published a report of a previously unrecognized - 4th - meningeal membrane located between the pia and arachnoid. Multiple features were claimed for this new membrane: a single cell layer marked by the transcription factor Prox1 that formed a barrier to low molecular weight substances and separated the subarachnoid space (SAS) into two fluid-filled compartments, not one as previously described. These features were further claimed to facilitate unidirectional glymphatic cerebrospinal fluid transport. These claims were immediately questioned by several researchers as misinterpretations of the authors' own data. The critics argued that (i) the 4th meningeal membrane as claimed did not exist as a separate structure but was part of the arachnoid, (ii) the "outer SAS" compartment was likely an artifactual subdural space created by the experimental procedures, and (iii) the 4th membrane barrier property was confused with the arachnoid barrier. Subsequent publications in late 2023 indeed showed that Prox1 + cells are embedded within the arachnoid and located immediately inside of and firmly attached to the arachnoid barrier cells by adherens junctions and gap junctions. In a follow-up study, published in this journal, the lead authors of the Science paper Kjeld Møllgård and Maiken Nedergaard reported additional observations they claim support the existence of a 4th meningeal membrane and the compartmentalization of the SAS into two non-communicating spaces. Their minor modification to the original paper was the 4th meningeal membrane was better observable at the ventral side of the brain than at the dorsal side where it was originally reported. The authors also claimed support for the existence of a 4th meningeal membrane in classical literature. Here, we outline multiple concerns over the new data and interpretation and argue against the claim there is prior support in the literature for a 4th meningeal membrane.

Discovery of the selective and nanomolar inhibitor of DPP-4 more potent than sitagliptin by structure-guided rational design.

Various therapeutic targets and approaches are commonly employed in the management of Type 2 Diabetes. These encompass diverse groups of drugs that target different mechanisms involved in glucose regulation. Inhibition of the DPP-4 enzyme has been proven an excellent target for antidiabetic drug design. Our previous work on discovering multitarget antidiabetic drugs led to the identification of a gallic acid-thiazolidinedione hybrid as a potent DPP4 inhibitor (IC50 = 36 nM). In current research, our efforts resulted in a new dihydropyrimidine-based scaffold with enhanced DPP4 inhibition potential. After virtual evaluation, the designed molecules with excellent interaction patterns and binding energy values were synthesized in the wet laboratory. The inhibition potential of synthesized compounds was assessed against the DPP-4 enzyme. Compound 46 with single digit IC50 value 2 nM exhibited 4-fold and 18-fold higher activity than Sitagliptin and our previously reported hybrid respectively. Moreover, compounds 46, 47 and 50 have shown manyfold selectivity against DPP8 and DPP9. Further pretreatment with compounds 43, 45-47 and 50 (at doses of 10 and 20 mg/kg) in OGTT conducted on rats resulted in a significant decrease in the serum glucose levels compared to the control group. In the long-term STZ-induced diabetic rats, tested compound 50 performed similarly to the reference drug. Molecular dynamics simulations and in-silico molecular docking studies were employed to elucidate the time-dependent interactions of inhibitors within the active sites of DPP4. The compounds examined in this work might serve as a possible lead in the development of effective diabetic mellitus treatments.

Dipeptidyl peptidase 4: A predictor of ferroptosis in ulcerative colitis.

BACKGROUND: With its rapidly increasing incidence and prevalence, ulcerative colitis (UC) has become a major global health challenge. Recent evidence suggests that ferroptosis plays a significant role in the development of UC. However, the relationship between ferroptosis and the progression of UC needs to be extensively studied. METHODS: The differentially expressed genes in UC patients were screened from the GEO database. The ferroptosis-related genes were obtained from FErrDB and GeneCards. The UC subtypes were identified with the R package "CancerSubtype" and evaluated with consensus clustering (CC) to identify gene expression patterns in patients with UC. The key genes were detected with qRT-PCR, Western blot, and immunohistochemistry in vitro and in vivo models. Ferroptosis was identified with western blotting on ferrotic-associated proteins and staining on Fe2+ with commercial FerroOrange kits. RESULTS: Dipeptidyl peptidase 4 (DPP4), also known as CD26, is a potential biomarker for ferroptosis in UC patients. Transcriptome sequencing data showed a positive correlation between decreased DPP4 expression and proinflammatory cytokines such as TNF-α, IL-6, and IL-ß, as well as immune cell infiltration in the colon tissues of UC patients. Furthermore, DPP4 was strongly associated with ferroptosis biomarkers, particularly in Subtype 2 of UC. Interestingly, our study also found that DPP4 expression was significantly reduced in RSL3-treated ferroptotic intestinal epithelial cells, more so than in LPS-treated cell models. Inhibition of DPP4 had a significant impact on the expression of ferroptotic biomarkers. Additionally, DPP4 expression was decreased in the colon tissues of DSS-treated mice, and the ferroptosis inhibitor Ferritin-1 effectively counteracted the effects of DSS on immune cell infiltration, colon length, and DPP4 expression. CONCLUSIONS: DPP4 can serve as a biomarker for ferroptosis in the diagnosis and management of UC.

Association of sodium-glucose cotransporter 2 inhibitors with risk of incident dementia and all-cause mortality in older patients with type 2 diabetes: A retrospective cohort study using the TriNetX US collaborative networks.

BACKGROUND: Limited evidence exists to support any specific medication over others to prevent dementia in older patients with type 2 diabetes (T2D). We investigated whether treatment with sodium-glucose cotransporter 2 (SGLT-2) inhibitors is associated with a lower risk of incident dementia and all-cause mortality, relative to dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RA). METHODS: In this retrospective, active-comparator cohort study, we used data from the TriNetX electronic health records network. Our primary cohort comprised patients with T2D aged ≥50 years, registered between January 2012 and December 2022. Patients with a history of dementia were excluded. We used Kaplan-Meier survival analysis to estimate the incidence of dementia and all-cause mortality in our cohort after they had used glucose-lowering drugs for at least 12 months. Propensity score matching was performed to balance the SGLT-2 inhibitor, DPP-4 inhibitor and GLP-1 RA cohorts. Subgroup analyses for sex and age were also conducted. RESULTS: Our first cohort comprised 193 948 patients treated with metformin and SGLT-2 inhibitors and an equal number of patients treated with metformin and DPP-4 inhibitors. In this cohort, the risk of dementia and all-cause mortality was lower in patients treated with SGLT-2 inhibitors than in those treated with DPP-4 inhibitors (hazard ratio [HR]: 0.62, 95% confidence interval [CI]: 0.59-0.65, for dementia; HR: 0.54, 95% CI: 0.52-0.56, for all-cause mortality). Our second cohort comprised 165 566 patients treated with metformin and SGLT-2 inhibitors and an equal number of patients treated with metformin and GLP-1 RAs. In this cohort, the risk of dementia and all-cause mortality was lower in those treated with SGLT-2 inhibitors than in those treated with GLP-1 RAs (HR: 0.92, 95% CI: 0.87-0.98, for dementia; HR: 0.88, 95% CI: 0.85-0.91, for all-cause mortality). CONCLUSIONS: The use of SGLT-2 inhibitor was associated with a lower risk of incident dementia and all-cause mortality in older adults with T2D compared to DPP-4 inhibitor and GLP-1 RA.

The effects of dipeptidyl peptidase-4 inhibitors on cardiac structure and function using cardiac magnetic resonance: a meta-analysis of clinical studies.

Objective: The aim of the study was to evaluate the effect of dipeptidyl peptidase-4 inhibitors (DPP4i) on cardiac structure and function by cardiac magnetic resonance (CMR). Research Methods & Procedures: Database including PubMed, Cochrane library, Embase and SinoMed for clinical studies of DPP4i on cardiac structure and function by CMR were searched. Two authors extracted the data and evaluated study quality independently. Mean difference (MD) or standardized MD and 95% confidence intervals (CI) were used for continuous variables. Review Manager 5.3 was used to performed the analysis. Results: Ten references (nine studies) were included in this meta-analysis. Most of the studies were assessed as well quality by the assessment of methodological quality. For clinical control studies, the merged MD values of △LVEF by fixed-effect model and the pooled effect size in favor of DPP4i was 1.55 (95% CI 0.35 to 2.74, P=0.01). Compared with positive control drugs, DPP4i can significantly improve the LVEF (MD=4.69, 95%CI=2.70 to 6.69), but no such change compared to placebo (MD=-0.20, 95%CI=-1.69 to 1.29). For single-arm studies and partial clinical control studies that reported LVEF values before and after DPP4i treatment, random-effect model was used to combine effect size due to a large heterogeneity (Chi2 = 11.26, P=0.02, I2 = 64%), and the pooled effect size in favor of DPP4i was 2.31 (95% CI 0.01 to 4.62, P=0.05). DPP4i significantly increased the Peak filling rate (PFR) without heterogeneity when the effect sizes of two single-arm studies were combined (MD=31.98, 95% CI 13.69 to 50.27, P=0.0006; heterogeneity test: Chi2 = 0.56, P=0.46, I2 = 0%). Conclusions: In summary, a possible benefit of DPP4i in cardiac function (as measured by CMR) was found, both including ventricular systolic function and diastolic function.

Exploring CD26-/lo subpopulations of lymphocytes in asthma phenotype and severity: A novel CD4+ T cell subset expressing archetypical granulocyte proteins.

BACKGROUND: Asthma pathology may induce changes in naïve/memory lymphocyte proportions assessable through the evaluation of surface CD26 (dipeptidyl peptidase 4/DPP4) levels. Our aim was to investigate the association of asthma phenotype/severity with the relative frequency of CD26-/lo, CD26int and CD26hi subsets within different lymphocyte populations. METHODS: The proportion of CD26-/lo, CD26int and CD26hi subsets within CD4+ effector T cells (Teff), total CD4- lymphocytes, γδ-T cells, NK cells and NKT cells was measured in peripheral blood samples from healthy (N = 30) and asthma (N = 119) donors with different phenotypes/severities by flow cytometry. We performed K-means clustering analysis and further characterised the CD4+CD26-/lo Teff cell subset by LC-MS/MS and immunofluorescence. RESULTS: Cluster analysis including clinical and flow cytometry data resulted in four groups, two of them with opposite inflammatory profiles (neutrophilic vs. eosinophilic). Neutrophilic asthma presented reduced CD4-CD26hi cells, which negatively correlated with systemic inflammation. Eosinophilic asthma displayed a general expansion of CD26-/lo subsets. Specifically, CD4+CD26-/lo Teff expansion was confirmed in asthma, especially in atopic patients. Proteomic characterisation of this subset with a TEM/TEMRA phenotype revealed upregulated levels of innate (e.g. MPO and RNASE2) and cytoskeleton/extracellular matrix (e.g. MMP9 and ACTN1) proteins. Immunofluorescence assays confirmed the presence of atypical proteins for CD4+ T cells, and an enrichment in 'flower-like' nuclei and MMP9/RNASE2 levels in CD4+CD26-/lo Teff compared to CD4+ T lymphocytes. CONCLUSION: There is an association between CD26 levels in different lymphocyte subsets and asthma phenotype/severity. CD4+CD26-/loTEMRA cells expressing innate proteins specific to eosinophils/neutrophils could be determinant in sustaining long-term inflammation in adult allergic asthma.

Identification of potential dipeptidyl peptidase IV inhibitors from the ConMedNP library by virtual screening, and molecular dynamics methods.

In this study, we screened novel dipeptidyl peptidase IV (DPP4) inhibitors from the ConMedNP library consisting of 3507 molecules. Interestingly, molecular docking, ADMET, and the anti-diabetic activity predictions suggest that three molecules, namely OTH_UD_XX06_1, GB19, and BMC_000104, have a high binding affinity toward DPP4. The molecular dynamics (MD) simulation results suggest that these hit molecules have a stable binding pose and occupy the binding pockets throughout the 200 ns simulation. The presence of intermolecular H-bonding between the ligands and DPP4 was observed throughout the simulation period. Thus, docking and MD results, predicted that the three compounds were the most potent DPP4 inhibitors that could putatively bind to the DPP4 active site via both conventional H-bonding and hydrophobic interactions. These results could aid the discovery of new drugs to treat type 2 diabetes.

Association between dipeptidyl peptidase-4 inhibitor use and risk of Parkinson's disease among patients with diabetes mellitus: a retrospective cohort study.

BACKGROUND: How a person's Parkinson disease (PD) risk is affected by dipeptidyl peptidase-4 (DPP-4) inhibitors remains unclear. We evaluated the association of PD risk with use of these inhibitors in individuals diagnosed as having diabetes mellitus (DM). METHODS: Individuals diagnosed as having new-onset DM were enrolled into the case group and comparison group, comprising patients who received a DPP-4 inhibitor and a sulfonylurea, respectively. These groups were matched through propensity score matching on the basis of income level, gender, urbanization level, enrollment year, age, and diabetes complications severity index score. The case group was divided into subgroups on the basis of whether they had a cumulative defined daily dose (cDDD) of <75, 75-150, or >150. The DPP-4 inhibitor-PD risk association was evaluated through a Cox proportional hazards model. The Bonferroni adjustment test was employed to adjust P-values and reduce the false positive rate. RESULTS: Compared with those in the comparison group (treatment with a sulfonylurea), patients with a DPP-4 inhibitor cDDD of >150 had a hazard ratio (HR) of 1.30 for PD development (95% confidence interval [CI]: 0.97-1.73; adjusted P = .263); the HRs for patients with a cDDD of <75 or 75-150 were 0.95 (95% CI: 0.71-1.27; adjusted P = .886) and 1.06 (95% CI: 0.75-1.50; adjusted P = .886), respectively. We noted nonsignificant differences regarding the associations between the use of the various DPP-4 inhibitors (linagliptin, saxagliptin, sitagliptin, and vildagliptin) and PD risk after adjustment for any individual inhibitor (adjusted P > .05). CONCLUSIONS: DPP-4 inhibitors were discovered in this study to not be associated with increased PD risk. This result was confirmed when the analysis was conducted individually for the 4 investigated DPP-4 inhibitors (sitagliptin, saxagliptin, linagliptin, and vildagliptin).

Repurposing antidiabetic drugs for Alzheimer's disease: A review of preclinical and clinical evidence and overcoming challenges.

Repurposing antidiabetic drugs for the treatment of Alzheimer's disease (AD) has emerged as a promising therapeutic strategy. This review examines the potential of repurposing antidiabetic drugs for AD treatment, focusing on preclinical evidence, clinical trials, and observational studies. In addition, the review aims to explore challenges and opportunities in repurposing antidiabetic drugs for AD, emphasizing the importance of well-designed clinical trials that consider patient selection criteria, refined outcome measures, adverse effects, and combination therapies to enhance therapeutic efficacy. Preclinical evidence suggests that glucagon-like peptide-1 (GLP-1) analogs, dipeptidyl peptidase-4 (DPP4) inhibitors, metformin, thiazolidinediones, and sodium-glucose co-transporter-2 (SGLT2) inhibitors exhibit neuroprotective effects in AD preclinical models. In preclinical studies, antidiabetic drugs have demonstrated neuroprotective effects by reducing amyloid beta (Aß) plaques, tau hyperphosphorylation, neuroinflammation, and cognitive impairment. Antidiabetic drug classes, notably GLP-1 analogs and SGLT2 inhibitors, and a reduced risk of dementia in patients with diabetes mellitus. While the evidence for DPP4 inhibitors is mixed, some studies suggest a potential protective effect. On the other hand, alpha-glucosidase inhibitors (AGIs) and sulfonylureas may potentially increase the risk, especially in those experiencing recurrent hypoglycemic events. Repurposing antidiabetic drugs for AD is a promising therapeutic strategy, but challenges such as disease heterogeneity, limited biomarkers, and benefits versus risk evaluation need to be addressed. Ongoing clinical trials in mild cognitive impairment (MCI) and early AD patients without diabetes will be crucial in determining the clinical efficacy and safety of the antidiabetic drugs, paving the way for potential treatments for AD.

Impact of DPP4 Inhibition on Survival in Patients With Metastatic Renal Cell Carcinoma and Type 2 Diabetes Mellitus.

BACKGROUND: Dipeptidyl peptidase IV (DPP4) is a cell surface receptor that possesses numerous substrates implicated in tumor growth and metastasis. Prior studies have suggested an association between DPP4 inhibition and increased progression-free survival (PFS) and overall survival (OS) in colorectal and lung cancers but no benefit in breast or pancreatic cancers. However, no studies to date have explored the impact of DPP4 inhibitors (DPP4i) in patients with metastatic renal cell carcinoma (mRCC). In this study we present a first-time analysis examining the impact of DPP4i use on PFS and OS in patients with mRCC and type 2 diabetes mellitus. METHODS: We performed a retrospective analysis of patients with diabetes and mRCC at the University of Virginia. The study group comprised those whose diabetic regimen included a DPP4i during mRCC treatment. The control group comprised patients whose diabetic regimen did not include a DPP4i during treatment. Cox regression analysis was utilized to determine the hazard ratios of progression and death between groups. RESULTS: Fifty-nine patients were eligible for the study, with 11 in the DPP4i group and 48 in the control group. Cancer progression occurred in 81.8% of patients in the DPP4i group and 66.7% in the control group. No statistically significant differences on PFS (HR: 1.60 [95% CI, 0.75-3.43]) or OS (HR: 0.69 [95% CI, 0.28-1.70]) were found between groups. CONCLUSIONS: This retrospective study explored the effect of DPP4i on outcomes in patients with mRCC and diabetes. DPP4i have been shown to have favorable effects on PFS and OS in some cancers but not in others. The results of this study suggest that DPP4i do not confer clinical benefit in patients with mRCC. Larger studies are warranted to better elucidate the effect of DPP4i in mRCC and the mechanisms underlying differential tumor response to these agents in different malignancies.

[P3]PP, a stable, long-acting pancreatic polypeptide analogue, evokes weight lowering and pancreatic beta-cell-protective effects in obesity-associated diabetes.

AIM: To thoroughly investigate the impact of sustained neuropeptide Y4 receptor (NPY4R) activation in obesity-associated diabetes. METHODS: Initially, the prolonged pharmacodynamic profile of the enzymatically stable pancreatic polypeptide (PP) analogue, [P3]PP, was confirmed in normal mice up to 24 h after injection. Subsequent to this, [P3]PP was administered twice daily (25 nmol/kg) for 28 days to high-fat-fed mice with streptozotocin-induced insulin deficiency, known as HFF/STZ mice. RESULTS: Treatment with [P3]PP for 28 days reduced energy intake and was associated with notable weight loss. In addition, circulating glucose was returned to values of approximately 8 mmol/L in [P3]PP-treated mice, with significantly increased plasma insulin and decreased glucagon concentrations. Glucose tolerance and glucose-stimulated insulin secretion were improved in [P3]PP-treated HFF/STZ mice, with no obvious effect on peripheral insulin sensitivity. Benefits on insulin secretion were associated with elevated pancreatic insulin content as well as islet and beta-cell areas. Positive effects on islet architecture were linked to increased beta-cell proliferation and decreased apoptosis. Treatment intervention also decreased islet alpha-cell area, but pancreatic glucagon content remained unaffected. In addition, [P3]PP-treated HFF/STZ mice presented with reduced plasma alanine transaminase and aspartate transaminase levels, with no change in circulating amylase concentrations. In terms of plasma lipid profile, triglyceride and cholesterol levels were significantly decreased by [P3]PP treatment, when compared to saline controls. CONCLUSION: Collectively, these data highlight for the first time the potential of enzymatically stable PP analogues for the treatment of obesity and related diabetes.

Sodium-glucose co-transporter-2 inhibitors versus dipeptidyl peptidase-4 inhibitors on major liver outcomes in metabolic dysfunction-associated steatotic liver disease.

AIM: To compare the effectiveness of sodium-glucose co-transporter-2 inhibitors (SGLT2is) with dipeptidyl peptidase-4 inhibitors (DPP4is) on major liver outcomes (MLO) in patients with type 2 diabetes (T2D) and metabolic dysfunction-associated steatotic liver disease (MASLD). MATERIALS AND METHODS: We included adult patients with T2D and MASLD, using metformin without specific liver conditions or surgeries, from the Merative MarketScan database. Patients initiating SGLT2is or DPP4is from 1 January 2014 to 31 December 2022 were identified. The primary outcome was time to MLO diagnosis. Overlap weighting balanced covariates, integrated with a Cox proportional hazards model for survival analysis. RESULTS: Among 44 651 patients, 22 100 initiated SGLT2is, and 22 551 began DPP4is. After weighting, the incidence rate of MLO in the SGLT2i group was 3.8 per 1000 person-years, and it was 3.9 per 1000 person-years in the DPP4i group, resulting in an adjusted hazard ratio (aHR) of 0.82 (95% CI, 0.60-1.10). SGLT2i initiation was not associated with cirrhosis (aHR: 0.77; 95% CI, 0.55-1.06) or hepatocellular carcinoma (aHR: 0.99; 95% CI, 0.47-1.83) separately. Subgroup and sensitivity analyses did not yield significant results. CONCLUSIONS: In patients with T2D and MASLD, SGLT2is did not show a lower risk of MLO compared with DPP4is. Clinicians should consider the overall patient conditions and the additional benefits of SGLT2is to support the decision to switch from DPP4is.

Glucagon-Like Peptide-1 Receptor Agonists and Risk of Parkinson's Disease in Patients with Type 2 Diabetes: A Population-Based Cohort Study.

BACKGROUND: Previous studies have suggested that glucagon-like peptide-1 receptor agonists (GLP-1RAs) may have a disease-modifying effect in the development of Parkinson's disease (PD), but population studies yielded inconsistent results. OBJECTIVE: The aim was to compare the risk of PD associated with GLP-1RAs compared to dipeptidyl peptidase 4 inhibitors (DPP4i) among older adults with type 2 diabetes (T2D). METHODS: Using U.S. Medicare administrative data from 2016 to 2020, we conducted a population-based cohort study comparing the new use of GLP-1RA with the new use of DPP4i among adults aged ≥66 years with T2D. The primary endpoint was a new diagnosis of PD. A stabilized inverse probability of treatment weighting (sIPTW)-adjusted Cox proportional hazards regression model was employed to estimate the hazard ratio (HR) and 95% confidence intervals (CI) for PD between GLP-1RA and DPP4i users. RESULTS: This study included 89,074 Medicare beneficiaries who initiated either GLP-1RA (n = 30,091) or DPP4i (n = 58,983). The crude incidence rate of PD was lower among GLP-1RA users than DPP4i users (2.85 vs. 3.92 patients per 1000 person-years). An sIPTW-adjusted Cox model showed that GLP-1RA users were associated with a 23% lower risk of PD than DPP4i users (HR, 0.77; 95% CI, 0.63-0.95). Our findings were largely consistent across different subgroup analyses such as sex, race, and molecular structure of GLP-1RA. CONCLUSION: Among Medicare beneficiaries with T2D, the new use of GLP-1RAs was significantly associated with a decreased risk of PD compared to the new use of DPP4i. © 2024 International Parkinson and Movement Disorder Society.

Comparison of renal prognosis between dipeptidyl peptidase-4 inhibitor users and non-users.

AIM: To evaluate the renal prognosis of dipeptidyl peptidase-4 inhibitor (DPP-4i) users and non-users using real-world Asian data. METHODS: Using databases from DeSC Healthcare, Inc., patients aged 30 years or older who used antidiabetic drugs from 2014 to 2021 were identified. Propensity score matching analyses were used to compare renal prognosis between DPP-4i users and non-users. The primary outcomes were estimated glomerular filtration rate (eGFR) decline and end-stage kidney disease (ESKD) development in the eGFR of 45 mL/min/1.73m2 or higher and eGFR of less than 45 mL/min/1.73m2 groups, respectively. RESULTS: In total, 65 375 and 9866 patients were identified in the eGFR of 45 mL/min/1.73m2 or higher and eGFR of less than 45 mL/min/1.73m2 groups, respectively. In the eGFR of 45 mL/min/1.73m2 or higher group, propensity score matching created 16 002 pairs. A significant difference was observed in the primary outcome of eGFR decline between DPP-4i users and non-users at 2 years (-2.31 vs. -2.56 mL/min/1.73m2: difference, 0.25 mL/min/1.73m2; 95% confidence interval [CI], 0.06-0.44) and 3 years (-2.75 vs. -3.41 mL/min/1.73m2: difference, 0.66 mL/min/1.73m2; 95% CI, 0.39-0.93). In the eGFR less than 45 mL/min/1.73m2 group, propensity score matching created 2086 pairs. After a mean of 2.2 years of observation, ESKD development was 1.15% and 2.30% in users and non-users, respectively, and Kaplan-Meier analysis revealed a significant difference (log rank P = .005). CONCLUSIONS: This retrospective real-world study revealed that patients using DPP-4is had a better renal prognosis than those not using DPP-4is.