The protective role of DPP4 inhibitors in atherosclerosis

HSPB1 suppresses oxLDL-induced vascular smooth muscle cell ferroptosis by inhibiting DPP4

BACKGROUND

Atherosclerosis is the major pathological basis of cardiovascular diseases. Vascular smooth muscle cell (VSMC) dysfunction and death induced by oxidized low-density lipoprotein (oxLDL) play a key role in atherosclerosis. Ferroptosis is a novel iron-dependent lipid peroxidation regulated cell death, which is implicated in atherosclerosis. However, whether oxLDL induces VSMC ferroptosis and the specific mechanism is unclear.

METHODS

To determine the effects of oxLDL on VSMC ferroptosis, LDH activity, MDA and Fe2+ content, glutathione peroxidase 4 (GPX4) expression and GPX enzyme activity were assayed. The level of lipid peroxidation was detected by C11 BODIPY fluorescence staining. RT-qPCR and Western blot were used to detect the mRNA and protein expressions of heat shock protein B1 (HSPB1), dipeptidyl peptidase 4 (DPP4) and nuclear factor kappa-B (NF-κB). The siRNAs, plasmids and Val-boropro were utilized to explore the roles of HSPB1/NF-κB/DPP4 in oxLDL-induced VSMC ferroptosis.

RESULTS

oxLDL increased LDH activity, Fe2+ content, lipid peroxidation and MDA content in VSMCs, which were inhibited by ferroptosis inhibitors Lip-1 and DFO. Moreover, oxLDL reduced GPX4 protein expression and GPX enzyme activity, indicating that oxLDL induces VSMC ferroptosis. Notably, HSPB1 inhibited oxLDL-induced VSMC ferroptosis by reducing the accumulation of Fe2+ and lipid peroxidation and increasing GPX4 expression and activity. In addition, HSPB1 suppressed oxLDL-induced VSMC ferroptosis by inhibiting DPP4 through NF-κB. Furthermore, Val-boropro could rescue oxLDL-induced ferroptosis in VSMCs with HSPB1 knockdown by inhibiting DPP4.

CONCLUSIONS

This study reveals for the first time that HSPB1 suppresses oxLDL-induced VSMC ferroptosis by inhibiting DPP4 through NF-κB, providing new strategies for the prevention and treatment of atherosclerosis.

Bile acids and incretins as modulators of obesity-associated atherosclerosis

Obesity is one of the major global health concerns of the 21st century, associated with many comorbidities such as type 2 diabetes mellitus (T2DM), metabolic dysfunction-associated steatotic liver disease, and early and aggressive atherosclerotic cardiovascular disease, which is the leading cause of death worldwide. Bile acids (BAs) and incretins are gut hormones involved in digestion and absorption of fatty acids, and insulin secretion, respectively. In recent years BAs and incretins are increasingly recognized as key signaling molecules, which target multiple tissues and organs, beyond the gastro-intestinal system. Moreover, incretin-based therapy has revolutionized the treatment of T2DM and obesity. This mini review highlights the current knowledge about dysregulations in BA homeostasis in obesity with a special focus on atherosclerosis as well as athero-modulating roles of incretins and currently available incretin-based therapies.

Transforming Diabetes Care: The Expanding Role of DPP-4 Inhibitors in Cardiovascular and Renal Protection

The approach to managing type 2 diabetes mellitus (T2DM) has significantly progressed, evolving beyond strict glycemic control to addressing the wider complications associated with the disease, including cardiovascular disease (CVD) and chronic kidney disease (CKD) [...].

Evaluation of the Effect of an α-Adrenergic Blocker, a PPAR-γ Receptor Agonist, and a Glycemic Regulator on Chronic Kidney Disease in Diabetic Rats

Diabetic nephropathy (DN) is a globally widespread complication of diabetes mellitus (DM). Research indicates that pioglitazone and linagliptin mitigate the risk of DN by reducing inflammation, oxidative stress, and fibrosis. The role of tamsulosin in DN is less studied, but it may contribute to reducing oxidative stress and inflammatory responses. The protective effects of combining pioglitazone, linagliptin, and tamsulosin on the kidneys have scarcely been investigated. This study examines the individual and combined effects of these drugs on DN in Wistar rats. Diabetic rats were treated with tamsulosin, pioglitazone, and linagliptin for six weeks. We assessed food and water intake, estimated glomerular filtration rate (eGFR), histological markers, urea, creatinine, glucose, NF-κB, IL-1, IL-10, TGF-β, and Col-IV using immunofluorescence and qPCR. The DN group exhibited hyperglycaemia, reduced eGFR, and tissue damage. Tamsulosin and linagliptin improved eGFR, decreased urinary glucose, and repaired tissue damage. Pioglitazone and its combinations restored serum and urinary markers and reduced tissue damage. Linagliptin lowered serum creatinine and tissue injury. In conclusion, tamsulosin, linagliptin, and pioglitazone demonstrated renoprotective effects in DN.

Risk of Pancreatitis With Incretin Therapies Versus Thiazolidinediones in the Veterans Health Administration

BACKGROUND

Incretin therapies, comprised of the dipeptidyl peptidase-4 inhibitors (DPP-4i) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs), have been increasingly utilized for the treatment of type 2 diabetes (T2DM). Previous studies have conflicting results regarding risk of pancreatitis associated with these agents-some suggest an increased risk and others find no correlation. Adverse event reporting systems indicate that incretin therapies are some of the most common drugs associated with reports of pancreatitis.

OBJECTIVES

This study aimed to compare the odds of developing pancreatitis in veterans with T2DM prescribed an incretin therapy versus thiazolidinediones (TZDs: pioglitazone and rosiglitazone) within the Veterans Health Administration (VHA).

METHODS

This was a retrospective cohort study analyzing veterans with T2DM first prescribed an incretin therapy or a TZD between January 1, 2011, and December 31, 2021. A diagnosis of pancreatitis within 365 days of being prescribed either therapy was counted as a positive case. Data was collected and analyzed utilizing VA's Informatics and Computing Infrastructure (VINCI) and an adjusted odds ratio was calculated.

RESULTS

The TZD cohort consisted of 42 912 patients compared with the incretin cohort of 304 811 patients. The TZD cohort had a pancreatitis incidence rate of 1.94 cases per 1000 patients. The incretin cohort had a incidence rate of 2.06 cases per 1000 patients. An adjusted odds ratio found no statistical difference of pancreatitis cases between the TZD and incretin cohorts (adjusted odds ratio [AOR] = 0.94, 95% CI [0.75, 1.18]).

CONCLUSION AND RELEVANCE

This retrospective cohort study of national VHA data found a relatively low incidence of pancreatitis in both cohorts, and an adjusted odds ratio found no statistical difference of pancreatitis in patients prescribed an incretin therapy compared with a control group. This data adds to growing evidence that incretin therapies do not seem to be associated with an increased risk of developing pancreatitis.

Endothelial dysfunction in vascular complications of diabetes: a comprehensive review of mechanisms and implications

Diabetic vascular complications are prevalent and severe among diabetic patients, profoundly affecting both their quality of life and long-term prospects. These complications can be classified into macrovascular and microvascular complications. Under the impact of risk factors such as elevated blood glucose, blood pressure, and cholesterol lipids, the vascular endothelium undergoes endothelial dysfunction, characterized by increased inflammation and oxidative stress, decreased NO biosynthesis, endothelial-mesenchymal transition, senescence, and even cell death. These processes will ultimately lead to macrovascular and microvascular diseases, with macrovascular diseases mainly characterized by atherosclerosis (AS) and microvascular diseases mainly characterized by thickening of the basement membrane. It further indicates a primary contributor to the elevated morbidity and mortality observed in individuals with diabetes. In this review, we will delve into the intricate mechanisms that drive endothelial dysfunction during diabetes progression and its associated vascular complications. Furthermore, we will outline various pharmacotherapies targeting diabetic endothelial dysfunction in the hope of accelerating effective therapeutic drug discovery for early control of diabetes and its vascular complications.

Stereochemical insights into β-amino-N-acylhydrazones and their impact on DPP-4 inhibition

Dipeptidyl peptidase IV (DPP-4) is a key enzyme that regulates several important biological processes and it is better known to be targeted by gliptins as a modern validated approach for the management of type 2 diabetes mellitus (T2DM). However, new generations of DPP-4 inhibitors capable of controlling inflammatory processes associated with chronic complications of T2DM are still needed. In this scenario, we report here the design by molecular modelling of new β-amino-N-acylhydrazones, their racemic synthesis, chiral resolution, determination of physicochemical properties and their DPP4 inhibitory potency. Theoretical and experimental approaches allowed us to propose a preliminary SAR, as well as to identify LASSBio-2124 (6) as a new lead for DPP-4 inhibition, with good physicochemical properties, favourable eudismic ratio, scalable synthesis and anti-diabetes effect in a proof-of-concept model. These findings represent an interesting starting point for the development of a new generation of DPP-4 inhibitors, useful in the treatment of T2DM and comorbidities.

Micro- and Macrovascular Effects of Inflammation in Peripheral Artery Disease-Pathophysiology and Translational Therapeutic Approaches

Inflammation has a critical role in the development and progression of atherosclerosis. On the molecular level, inflammatory pathways negatively impact endothelial barrier properties and thus, tissue homeostasis. Conformational changes and destruction of the glycocalyx further promote pro-inflammatory pathways also contributing to pro-coagulability and a prothrombotic state. In addition, changes in the extracellular matrix composition lead to (peri-)vascular remodelling and alterations of the vessel wall, e.g., aneurysm formation. Moreover, progressive fibrosis leads to reduced tissue perfusion due to loss of functional capillaries. The present review aims at discussing the molecular and clinical effects of inflammatory processes on the micro- and macrovasculature with a focus on peripheral artery disease.

Non-Specific Inhibition of Dipeptidyl Peptidases 8/9 by Dipeptidyl Peptidase 4 Inhibitors Negatively Affects Mesenchymal Stem Cell Differentiation

DPP4 may play a relevant role in MSC differentiation into osteoblasts or adipocytes. Dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4i), such as sitagliptin and vildagliptin, are used as antidiabetic drugs. However, vildagliptin is not a specific DPP4i and also inhibits DPP8/9, which is involved in energy metabolism and immune regulation. The aim of this study is to evaluate how sitagliptin, vildagliptin or 1G244 (a DPP8/9 specific inhibitor) may influence cell viability, as well as osteogenic and adipogenic differentiation in human mesenchymal stem cells (MSC). Viability, apoptosis, osteoblastogenesis and adipogenesis markers, as well as protein synthesis of β-catenin, were studied in MSC cultures induced to differentiate into osteoblasts or adipocytes in the presence or absence of sitagliptin, vildagliptin or 1G244. The two tested DPP4i did not affect MSC viability, but 1G244 significantly decreased it in MSC and osteoblast-induced cells. Additionally, 1G244 and vildagliptin inhibited osteogenesis and adipogenesis, unlike sitagliptin. Therefore, inhibition of DPP4 did not affect MSC viability and differentiation, whereas inhibition of DPP8/9 negatively affected MSC. To the best of our knowledge, these results show for the first time that DPP8/9 have an important role in the viability and differentiation of human MSC. This data can be considered for human clinical use of drugs affecting DPP8/9 activity.

Incretins-Based Therapies and Their Cardiovascular Effects: New Game-Changers for the Management of Patients with Diabetes and Cardiovascular Disease

Atherosclerosis is the leading cause of death worldwide, especially in patients with type 2 diabetes mellitus (T2D). GLP-1 receptor agonists and DPP-4 inhibitors were demonstrated to play a markedly protective role for the cardiovascular system beyond their glycemic control. Several cardiovascular outcome trials (CVOT) reported the association between using these agents and a significant reduction in cardiovascular events in patients with T2D and a high cardiovascular risk profile. Moreover, recent evidence highlights a favorable benefit/risk profile in myocardial infarction and percutaneous coronary revascularization settings. These clinical effects result from their actions on multiple molecular mechanisms involving the immune system, platelets, and endothelial and vascular smooth muscle cells. This comprehensive review specifically concentrates on these cellular and molecular processes mediating the cardiovascular effects of incretins-like molecules, aiming to improve clinicians' knowledge and stimulate a more extensive use of these drugs in clinical practice as helpful cardiovascular preventive strategies.

A bibliometric perspective to the most cited diabetes articles

Aim

This bibliometric analysis aims to evaluate the characteristics and impact of the top 100 cited articles published under the title of diabetes mellitus.

Metods

We performed to define the most cited articles in diabetes research by using the Web of Science. The papers were analyzed in terms of their year of publication, journal of publication, authors, impact factor (IF), total citations number, the average number of citations per year, studies topic, and type.

Results

The number of citations ranged from 1519 to 17.298. They were published from 1987 to 2018. The most cited articles were published in the New England Journal of Medicine (n = 26), followed by Diabetes Care (n = 17) and Lancet (n = 9). The original scientific paper was the most popular article type (46%), followed by review article (36%). The generality studies' subject was about treatment (n = 22), followed by pathogenesis (n = 19), etiology and risk factors (n = 16), diagnosis, screening, classification (n = 15), epidemiology (n = 11), prevention (n = 11) and complications (n = 6). There was a correlation between the average number of citations per year (ACpY) and IF (p = < 0.010, r = 0.259), citations and ACpY (p = < 0.001, r = 0.646), citations and time (p = 0.008, r = 0.266).

Conclusion

This study showed that original scientific papers were the most-cited and more articles were published in influential journals. Articles on diabetes treatment and pathogenesis were popular topics. Future interventions should focus on the management and prevention of diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01199-0.

The influence of dipeptidyl peptidase-4 inhibitor on the progression of type B intramural hematoma

Objectives

Investigating whether dipeptidyl peptidase-4 inhibitors (DPP4i) could influence the progression of type B intramural hematoma (IMHB) in patients with diabetes mellitus (DM).

Materials and methods

Uncomplicated IMHB patients were matched by age, sex, and body mass index. Cox proportional hazard models were constructed to identify risk factors. A Kaplan–Meier survival analysis was used to estimate all-cause and aorta-related mortality.

Results

Ninety-six matched IMHB patients were divided into Group A (n = 32, IMHB patients without DM), Group B (n = 32, IMHB patients with DMreceiving oral antidiabetic drugs [without DPP4i]) and Group C (n = 32, IMHB patients with DM receiving oral antidiabetic drugs [with DPP4i]). Group C had the lowest rate of aorta-related adverse events (3.1%), aorta-related mortality (0.0%) and reintervention (3.1%). Cox proportional hazard models revealed that a lower eosinophil count (per 0.1, HR, 0.48; 95% CI, 0.29–0.79, P = 0.004) and a higher neutrophil to lymphocyte ratio (NLR) (HR, 1.13; 95% CI, 1.05–1.21, P = 0.001) were associated with higher occurrences of aorta-related adverse events. A lower eosinophil count (per 0.1, HR, 0.40; 95% CI, 0.18–0.89, P = 0.025) and a higher NLR (HR, 1.19; 95% CI, 1.08–1.32, P = 0.001) were also associated with increased aorta-related mortality.

Conclusion

DPP4i administration in DM patients with IMHB was associated with lower aorta-related mortality and more benign progression than in those who did not receive DPP4i or those without DM. Furthermore, a higher eosinophil count and a lower NLR ratio are potential protective factors that may explain the potential therapeutic benefit of DPP4i.

Crosstalk between incretin hormones, Th17 and Treg cells in inflammatory diseases

Intestinal epithelial cells constantly crosstalk with the gut microbiota and immune cells of the gut lamina propria. Enteroendocrine cells, secrete hormones, such as incretin hormones, which participate in host physiological events, such as stimulating insulin secretion, satiety, and glucose homeostasis. Interestingly, evidence suggests that the incretin pathway may influence immune cell activation. Consequently, drugs targeting the incretin hormone signaling pathway may ameliorate inflammatory diseases such as inflammatory bowel diseases, cancer, and autoimmune diseases. In this review, we discuss how these hormones may modulate two subsets of CD4 + T cells, the regulatory T cells (Treg)/Th17 axis important for gut homeostasis: thus, preventing the development and progression of inflammatory diseases. We also summarize the main experimental and clinical findings using drugs targeting the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide (GLP-1) signaling pathways and their great impact on conditions in which the Treg/Th17 axis is disturbed such as inflammatory diseases and cancer. Understanding the role of incretin stimulation in immune cell activation and function, might contribute to new therapeutic designs for the treatment of inflammatory diseases, autoimmunity, and tumors.

Reactive Oxygen Species Scavenging Nanomedicine for the Treatment of Ischemic Heart Disease

Ischemic heart disease (IHD) is the leading cause of disability and mortality worldwide. Reactive oxygen species (ROS) have been shown to play key roles in the progression of diabetes, hypertension, and hypercholesterolemia, which are independent risk factors that lead to atherosclerosis and the development of IHD. Engineered biomaterial-based nanomedicines are under extensive investigation and exploration, serving as smart and multifunctional nanocarriers for synergistic therapeutic effect. Capitalizing on cell/molecule-targeting drug delivery, nanomedicines present enhanced specificity and safety with favorable pharmacokinetics and pharmacodynamics. Herein, the roles of ROS in both IHD and its risk factors are discussed, highlighting cardiovascular medications that have antioxidant properties, and summarizing the advantages, properties, and recent achievements of nanomedicines that have ROS scavenging capacity for the treatment of diabetes, hypertension, hypercholesterolemia, atherosclerosis, ischemia/reperfusion, and myocardial infarction. Finally, the current challenges of nanomedicines for ROS-scavenging treatment of IHD and possible future directions are discussed from a clinical perspective.

CD14 and CD26 from serum exosomes are associated with type 2 diabetes, exosomal Cystatin C and CD14 are associated with metabolic syndrome and atherogenic index of plasma

Background

Exosomes are microvesicles that actively participate in signaling mechanisms and depending on their content can contribute to the development of different pathologies, such as diabetes and cardiovascular disease.

Objective

The aim of this study was to evaluate the association of cystatin C, CD26, and CD14 proteins in serum exosomes from patients with Type 2 Diabetes (T2D), metabolic syndrome (MetS), and atherogenic index of plasma (AIP).

Methods

Serum exosomes were isolated by ultracentrifugation from 147 individuals with and without diabetes. Both anthropometric and metabolic parameters were registered from everyone. The levels of exosomal proteins cystatin C, CD26, and CD14 were quantified by ELISA. The association between protein levels and T2D or atherogenic risk factors was analyzed by linear regression and generalized regression models.

Results

We observed a significant correlation of increased glucose with elevated levels of Cystatin C, and an effect of T2D on the levels of CD26 (β = 45.8 pg/µg; p = 0.001) and CD14 (β = 168 pg/µg; p < 0.001) compared to subjects without T2D. CD14 was significantly related to T2D, metabolic syndrome, glucose, and the Atherogenic Index of Plasma (AIP). Additionally, we observed a significant effect of metabolic syndrome MetS on the increase of exosomal Cystatin C and CD14.

Conclusions

T2D may contribute to the increase of CD14 protein contained in exosomes, as well as to the predisposition of atherogenic events development due to its relationship with the increase in serum triglyceride concentrations and the AIP score. Finally, the increased levels of CD14 and Cystatin C in exosomes are related to MetS. The analysis of exosome contents of diabetic patients remains an incipient field, so extensive characterization is crucial for their use as biomarkers or to analyze their possible contribution to diabetic complications.

Glycaemic Control in Patients Undergoing Percutaneous Coronary Intervention: What Is the Role for the Novel Antidiabetic Agents? A Comprehensive Review of Basic Science and Clinical Data

Coronary artery disease (CAD) remains one of the most important causes of morbidity and mortality worldwide, and revascularization through percutaneous coronary interventions (PCI) significantly improves survival. In this setting, poor glycaemic control, regardless of diabetes, has been associated with increased incidence of peri-procedural and long-term complications and worse prognosis. Novel antidiabetic agents have represented a paradigm shift in managing patients with diabetes and cardiovascular diseases. However, limited data are reported so far in patients undergoing coronary stenting. This review intends to provide an overview of the biological mechanisms underlying hyperglycaemia-induced vascular damage and the contrasting actions of new antidiabetic drugs. We summarize existing evidence on the effects of these drugs in the setting of PCI, addressing pre-clinical and clinical studies and drug-drug interactions with antiplatelet agents, thus highlighting new opportunities for optimal long-term management of these patients.

Mechanisms of antidiabetic drugs and cholesterol efflux: A clinical perspective

Reverse cholesterol transport (RCT) is a physiological process that reduces excess cholesterol in the body. Cholesterol efflux (CE), an important step in RCT, is mainly mediated by ATP-binding cassette transporters A1 and G1 and has a significant role in atheroprotection. Moreover, impairments in CE can lead to the development of diabetes and fatty liver disease. In this review, we summarize the possible effects of hypoglycemic agents on CE and how this might influence atherosclerosis and dyslipidemia-related pathologies. Newer antidiabetic agents could have significant potential for targeting CE and preventing or alleviating atherosclerosis, obesity, and liver steatosis, and simultaneously improving insulin secretion. However, more research is warranted to interpret the clinical relevance of these data.

Influence of Dipeptidyl Peptidase-4 (DPP4) on Mesenchymal Stem-Cell (MSC) Biology: Implications for Regenerative Medicine - Review

Dipeptidyl peptidase IV (DPP4) is a ubiquitous protease that can be found in membrane-anchored or soluble form. Incretins are one of the main DPP4 substrates. These hormones regulate glucose levels, by stimulating insulin secretion and decreasing glucagon production. Because DPP4 levels are high in diabetes, DPP4 inhibitor (DPP4i) drugs derived from gliptin are widespread used as hypoglycemic agents for its treatment. However, as DPP4 recognizes other substrates such as chemokines, growth factors and neuropeptides, pleiotropic effects have been observed in patients treated with DPP4i. Several of these substrates are part of the stem-cell niche. Thus, they may affect different physiological aspects of mesenchymal stem-cells (MSC). They include viability, differentiation, mobilization and immune response. MSC are involved in tissue homeostasis and regeneration under both physiological and pathological conditions. Therefore, such cells and their secretomes have a high clinical potential in regenerative medicine. In this context, DPP4 activity may modulate different aspects of MSC regenerative capacity. Therefore, the aim of this review is to analyze the effect of different DPP4 substrates on MSC. Likewise, how the regulation of DPP4 activity by DPP4i can be applied in regenerative medicine. That includes treatment of cardiovascular and bone pathologies, cutaneous ulcers, organ transplantation and pancreatic beta-cell regeneration, among others. Thus, DPP4i has an important clinical potential as a complement to therapeutic strategies in regenerative medicine. They involve enhancing the differentiation, immunomodulation and mobilization capacity of MSC for regenerative purposes.

Trelagliptin ameliorates IL-1β-impaired chondrocyte function via the AMPK/SOX-9 pathway

Chondrocyte dysregulation plays a critical role in the development of osteoarthritis (OA). The pro-inflammatory cytokine interleukin-1β (IL-1β) activates chondrocytes and degrades the structural extracellular matrix (ECM). These events are the important mechanism of OA. Trelagliptin, a selective inhibitor of dipeptidyl Peptidase 4 (DPP-4) used for the treatment of type 2 diabetes mellitus (T2DM), has displayed a wide range of anti-inflammatory capacities. The effects of Trelagliptin in OA and chondrocytes have not been tested before. Here, we show that Trelagliptin mitigates IL-1β-induced production of inflammatory cytokines such as interleukin 6 (IL-6), interleukin 8 (IL-8), and tumor necrosis factor-alpha (TNF-α) in human chondrocytes. Trelagliptin ameliorates IL-1β-induced oxidative stress by reducing the generation of reactive oxygen species (ROS). Particularly, the presence of Trelagliptin prevents IL-1β-induced reduction of Acan genes and the protein Aggrecan. Moreover, we show that Trelagliptin restores IL-1β-induced reduction of SOX-9 and that the knockdown of SOX-9 abolishes the protective effects of Trelagliptin. Mechanistically, we demonstrate that AMPK is required for the amelioration of Trelagliptin on SOX-9- reduction by IL-1β. Collectively, our study demonstrates that the DPP-4 inhibitor Trelagliptin has a protective effect on chondrocyte function. Trelagliptin may have the potential role to antagonize chondrocyte-derived inflammation in OA.

Cardiovascular events and all-cause mortality in patients with type 2 diabetes treated with dipeptidyl peptidase-4 inhibitors: An extensive meta-analysis of randomized controlled trials

AIMS

Meta-analyses of randomized trials on Dipeptidyl Peptidase-4 inhibitors (DPP4i) reported discordant results on major cardiovascular events (MACE), mortality, and heart failure. Aim of this meta-analysis of randomized trials is the assessment of the cardiovascular safety of DPP4i.

DATA SYNTHESIS

A Medline, Embase, Cochrane database search for sitagliptin, vildagliptin, omarigliptin, saxagliptin, alogliptin, trelagliptin, anagliptin, linagliptin, gemigliptin, evogliptin, and teneligliptin was performed up to up January 1st, 2020. All trials with a duration ≥24 weeks and comparing the effects of DPP4i with placebo or active drugs were collected. Mantel-Haenszel odds ratio (MH-OR) with 95% Confidence Interval (95% CI) was calculated for all outcomes defined above. A total of 182 eligible trials were identified. DPP-4i were not associated with an increased risk of MACE (MH-OR 0.99 [0.93, 1.04]), all-cause mortality (MH-OR 0.99 [0.93, 1.06]), and heart failure (MH-OR 1.05 [0.96, 1.15]) with no significant differences across individual molecules, except for saxagliptin, which was associated with an increased risk of heart failure.

CONCLUSIONS

As a class, DPP4i are not associated with any increase or reduction of MACE, all-cause mortality, and heart failure. Saxagliptin seems to be associated with an increased risk of hospitalization for heart failure.

The Expression of Genes Related to Lipid Metabolism and Metabolic Disorders in Children before and after Hematopoietic Stem Cell Transplantation-A Prospective Observational Study

Metabolic disorders in children after hematopoietic stem cell transplantation (HSCT) are poorly characterized. However, it is known that dyslipidemia and insulin resistance are particularly common in these patients. We conducted a prospective study of 27 patients treated with HSCT to assess the possibility of predicting these abnormalities. We measured gene expressions using a microarray technique to identify differences in expression of genes associated with lipid metabolism before and after HSCT. In patients treated with HSCT, total cholesterol levels were significantly higher after the procedure compared with the values before HSCT. Microarray analysis revealed statistically significant differences in expressions of three genes, DPP4, PLAG1, and SCD, after applying the Benjamini-Hochberg procedure (pBH < 0.05). In multiple logistic regression, the increase of DPP4 gene expression before HCST (as well as its change between pre- and post-HSCT status) was associated with dyslipidemia. In children treated with HSCT, the burden of lipid disorders in short-term follow-up seems to be lower than before the procedure. The expression pattern of DPP4 is linked with dyslipidemia after the transplantation.

Endothelial Dysfunction in Atherosclerotic Cardiovascular Diseases and Beyond: From Mechanism to Pharmacotherapies

The endothelium, a cellular monolayer lining the blood vessel wall, plays a critical role in maintaining multiorgan health and homeostasis. Endothelial functions in health include dynamic maintenance of vascular tone, angiogenesis, hemostasis, and the provision of an antioxidant, anti-inflammatory, and antithrombotic interface. Dysfunction of the vascular endothelium presents with impaired endothelium-dependent vasodilation, heightened oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, and endothelial cell senescence. Recent studies have implicated altered endothelial cell metabolism and endothelial-to-mesenchymal transition as new features of endothelial dysfunction. Endothelial dysfunction is regarded as a hallmark of many diverse human panvascular diseases, including atherosclerosis, hypertension, and diabetes. Endothelial dysfunction has also been implicated in severe coronavirus disease 2019. Many clinically used pharmacotherapies, ranging from traditional lipid-lowering drugs, antihypertensive drugs, and antidiabetic drugs to proprotein convertase subtilisin/kexin type 9 inhibitors and interleukin 1β monoclonal antibodies, counter endothelial dysfunction as part of their clinical benefits. The regulation of endothelial dysfunction by noncoding RNAs has provided novel insights into these newly described regulators of endothelial dysfunction, thus yielding potential new therapeutic approaches. Altogether, a better understanding of the versatile (dys)functions of endothelial cells will not only deepen our comprehension of human diseases but also accelerate effective therapeutic drug discovery. In this review, we provide a timely overview of the multiple layers of endothelial function, describe the consequences and mechanisms of endothelial dysfunction, and identify pathways to effective targeted therapies. SIGNIFICANCE STATEMENT: The endothelium was initially considered to be a semipermeable biomechanical barrier and gatekeeper of vascular health. In recent decades, a deepened understanding of the biological functions of the endothelium has led to its recognition as a ubiquitous tissue regulating vascular tone, cell behavior, innate immunity, cell-cell interactions, and cell metabolism in the vessel wall. Endothelial dysfunction is the hallmark of cardiovascular, metabolic, and emerging infectious diseases. Pharmacotherapies targeting endothelial dysfunction have potential for treatment of cardiovascular and many other diseases.

Effect of linagliptin on glucose metabolism and pancreatic beta cell function in patients with persistent prediabetes after metformin and lifestyle

The goal of the study was to evaluate the effect of adding linagliptin to metformin and lifestyle on glucose levels and pancreatic β-cell function in patients with persistent impaired glucose tolerance (IGT) after 12 months of metformin and lifestyle. A single center parallel double-blind randomized clinical trial with 6 months of follow-up was performed in patients with persistent IGT after 12 months of treatment with metformin and lifestyle; patients were randomized to continue with metformin 850 mg twice daily (M group, n = 12) or linagliptin/metformin 2.5/850 mg twice daily (LM group, n = 19). Anthropometric measurements were obtained by standard methods and by bioelectrical impedance; glucose was measured by dry chemistry, insulin by chemiluminescence, and pancreatic β-cell function was calculated with the disposition index using glucose and insulin values during oral glucose tolerance test (OGTT) and adjusting by insulin sensitivity. The main outcomes were glucose levels during OGTT and pancreatic β-cell function. Patients in the LM group had a reduction in weight (-1.7 ± 0.6, p < 0.05) and body mass index (BMI, -0.67 ± 0.2, p < 0.05). Glucose levels significantly improved in LM group with a greater reduction in the area under the glucose curve during OGTT (AUCGluc_{0_120min}) as compared to the M group (-4425 ± 871 vs -1116 ± 1104 mg/dl/120 min, p < 0.001). Pancreatic β-cell function measured with the disposition index, improved only in LM group (2.3 ± 0.23 vs 1.7 ± 0.27, p 0.001); these improvements persisted after controlling for OGTT glucose levels. The differences in pancreatic β-cell function persisted also after pairing groups for basal AUCGluc_{0_120min}. The addition of linagliptin to patients with persistent IGT after 12 months of treatment with metformin and lifestyle, improved glucose levels during OGTT and pancreatic β-cell function after 6 months of treatment.Trial registration: Clinicaltrials.gov with the ID number NCT04088461.

Biological Context Linking Hypertension and Higher Risk for COVID-19 Severity

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), represents a public health crisis of major proportions. Advanced age, male gender, and the presence of comorbidities have emerged as risk factors for severe illness or death from COVID-19 in observation studies. Hypertension is one of the most common comorbidities in patients with COVID-19. Indeed, hypertension has been shown to be associated with increased risk for mortality, acute respiratory distress syndrome, need for intensive care unit admission, and disease progression in COVID-19 patients. However, up to the present time, the precise mechanisms of how hypertension may lead to the more severe manifestations of disease in patients with COVID-19 remains unknown. This review aims to present the biological plausibility linking hypertension and higher risk for COVID-19 severity. Emphasis is given to the role of the renin-angiotensin system and its inhibitors, given the crucial role that this system plays in both viral transmissibility and the pathophysiology of arterial hypertension. We also describe the importance of the immune system, which is dysregulated in hypertension and SARS-CoV-2 infection, and the potential involvement of the multifunctional enzyme dipeptidyl peptidase 4 (DPP4), that, in addition to the angiotensin-converting enzyme 2 (ACE2), may contribute to the SARS-CoV-2 entrance into target cells. The role of hemodynamic changes in hypertension that might aggravate myocardial injury in the setting of COVID-19, including endothelial dysfunction, arterial stiffness, and left ventricle hypertrophy, are also discussed.

Pyrazole Incorporated New Thiosemicarbazones: Design, Synthesis and Investigation of DPP-4 Inhibitory Effects

Dipeptidyl peptidase-4 (DPP-4) inhibition has been recognized as a promising approach to develop safe and potent antidiabetic agents for the management of type 2 diabetes. In this context, new thiosemicarbazones (2a-o) were prepared efficiently by the reaction of aromatic aldehydes with 4-[4-(1H-pyrazol-1-yl)phenyl]thiosemicarbazide (1), which was obtained via the reaction of 4-(1H-pyrazol-1-yl)phenyl isothiocyanate with hydrazine hydrate. Compounds 2a-o were evaluated for their DPP-4 inhibitory effects based on a convenient fluorescence-based assay. 4-[4-(1H-pyrazol-1-yl)phenyl]-1-(4-bromobenzylidene)thiosemicarbazide (2f) was identified as the most effective DPP-4 inhibitor in this series with an IC₅₀ value of 1.266 ± 0.264 nM when compared with sitagliptin (IC₅₀ = 4.380 ± 0.319 nM). MTT test was carried out to assess the cytotoxic effects of compounds 2a-o on NIH/3T3 mouse embryonic fibroblast (normal) cell line. According to cytotoxicity assay, compound 2f showed cytotoxicity towards NIH/3T3 cell line with an IC₅₀ value higher than 500 µM pointing out its favourable safety profile. Molecular docking studies indicated that compound 2f presented π-π interactions with Arg358 and Tyr666 via pyrazole scaffold and 4-bromophenyl substituent, respectively. Overall, in vitro and in silico studies put emphasis on that compound 2f attracts a great notice as a drug-like DPP-4 inhibitor for further antidiabetic research.