Potential roles for eNOS and NrF2 /HO-1 signaling in the ameliorative effect of lixisenatide on diabetes-induced kidney injury in rats and its amplification by ticagrelor co-administration.

Antioxidant and anti-inflammatory effects of lixisenatide (LX) and ticagrelor (TC) have been previously identified in type 2 diabetes mellitus (T2DM). Diabetic nephropathy is one of the major complications of T2DM. In the current study, we examined the potential protective effects of LX and TC on experimentally induced diabetic nephropathy in T2DM rats and their possible molecular mechanisms. To examine this possibility, rats were fed a high-fat diet (HFD) for 12 weeks, followed by a single injection of 35 mg/kg streptozotocin (STZ) to induce T2DM. 10 µg/kg LX and 25 mg/kg TC were given alone or in combination to T2DM rats for 4 weeks. The kidney examination of T2DM rats showed clear deterioration. T2DM rats exhibited significantly higher body weight, blood glucose, hemostatic model assessment for insulin resistance (HOMA-IR), blood urea nitrogen (BUN), serum creatinine, kidney reactive oxygen species (ROS), nuclear factor-κ B (NF-κ B), and transforming growth factor-ß (TGF-ß ), and significantly lower serum insulin, urine creatinine, creatinine clearance (CRCL), kidney superoxide dismutase (SOD), glutathione reduced (GSH), nuclear factor erythroid 2 (NrF2 ), heme oxygenase-1 (HO-1), and endothelial nitric oxide synthase (eNOS) when compared to control rats. Single treatment with LX or TC showed obvious ameliorative effects on kidney complications in T2DM rats, with more ameliorative effects with the combined administration of both drugs. Conclusion: Our investigation found that both LX and TC could significantly ameliorate the development of diabetic nephropathy via stimulating NrF2 /HO-1 antioxidant pathway in addition to increasing eNOS and decreasing NF-κ B renal tissue concentrations, and these effects were markedly augmented by their combined administration.

Time-in-range derived from self-measured blood glucose in people with type 2 diabetes advancing to iGlarLixi: A participant-level pooled analysis of three phase 3 LixiLan randomized controlled trials.

AIM: To evaluate the efficacy of a fixed-ratio combination of insulin glargine 100 U/mL plus lixisenatide (iGlarLixi) in people with type 2 diabetes (T2D) using derived time-in-range (dTIR). METHODS: Participant-level data from LixiLan-L, LixiLan-O and LixiLan-G were pooled and dTIR (70-180 mg/dL), derived time-above-range (> 180 mg/dL) and derived time-below-range (dTBR; < 70 mg/dL) were calculated from participant seven-point self-monitored blood glucose profiles. RESULTS: This pooled analysis included data from 2420 participants receiving iGlarLixi (n = 1093), iGlar (n = 836), Lixi (n = 234) or a glucagon-like peptide-1 receptor agonist (GLP-1 RA) (n = 257). Numerically greater improvements in least square (LS) means dTIR were seen from baseline to end of treatment (EOT) with iGlarLixi (25.7%) versus iGlar (15.8%), Lixi (11.7%) or GLP-1 RA (16.2%). At EOT, the mean (standard deviation) dTBR was 0.71% ± 3.4%, 0.61% ± 3.2%, 0.08% ± 1.0% and 0.0% ± 0.0% for iGlarLixi, iGlar, Lixi and GLP-1 RA, respectively. In a subgroup analysis, participants aged younger than 65 years (n = 1690) and 65 years or older (n = 713) showed numerically greater improvements in LS means dTIR from baseline to EOT with iGlarLixi versus iGlar, Lixi or GLP-1 RA. CONCLUSIONS: iGlarLixi achieved improvements in dTIR, with low dTBR values, providing further evidence to inform clinical outcomes with the use of iGlarLixi.

In early Parkinson disease, daily subcutaneous lixisenatide reduced motor disability progression at 12 mo.

SOURCE CITATION: Meissner WG, Remy P, Giordana C, et al; LIXIPARK Study Group. Trial of lixisenatide in early Parkinson's disease. N Engl J Med. 2024;390:1176-1185. 38598572.

Lead-in calorie restriction enhances the weight-lowering efficacy of incretin hormone-based pharmacotherapies in mice.

OBJECTIVES: The potential benefits of combining lifestyle changes with weight loss pharmacotherapies for obesity treatment are underexplored. Building on recent clinical observations, this study aimed to determine whether "lead-in" calorie restriction before administering clinically approved weight loss medications enhances the maximum achievable weight loss in preclinical models. METHODS: Diet-induced obese mice (DIO) were exposed to 7 or 14 days of calorie restriction before initiating treatment with semaglutide (a glucagon-like peptide-1 receptor (GLP-1R) agonist), tirzepatide (a GLP-1R/glucose insulinotropic peptide receptor (GIPR) co-agonist), or setmelanotide (a melanocortin-4 receptor (MC4R) agonist). Follow-up assessments using indirect calorimetry determined the contributions of energy intake and expenditure linked to consecutive exposure to dieting followed by pharmacotherapy. RESULTS: Calorie restriction prior to treatment with semaglutide or tirzepatide enhanced the weight loss magnitude of both incretin-based therapies in DIO mice, reflected by a reduction in fat mass and linked to reduced energy intake and a less pronounced adaptive drop in energy expenditure. These benefits were not observed with the MC4R agonist, setmelanotide. CONCLUSIONS: Our findings provide compelling evidence that calorie restriction prior to incretin-based therapy enhances the achievable extent of weight loss, as reflected in a weight loss plateau at a lower level compared to that of treatment without prior calorie reduction. This work suggests that more intensive lifestyle interventions should be considered prior to pharmacological treatment, encouraging further exploration and discussion of the current standard of care.

Clinical Outcomes of Tirzepatide or GLP-1 Receptor Agonists in Individuals With Type 2 Diabetes.

Importance: Despite its demonstrated benefits in improving cardiovascular risk profiles, the association of tirzepatide with mortality and cardiovascular and kidney outcomes compared with glucagon-like peptide 1 receptor agonists (GLP-1 RAs) remains unknown. Objective: To investigate the association of tirzepatide with mortality and adverse cardiovascular and kidney outcomes compared with GLP-1 RAs in patients with type 2 diabetes. Design, Setting, and Participants: This retrospective cohort study used US Collaborative Network of TriNetX data collected on individuals with type 2 diabetes aged 18 years or older initiating tirzepatide or GLP-1 RA between June 1, 2022, and June 30, 2023; without stage 5 chronic kidney disease or kidney failure at baseline; and without myocardial infarction or ischemic or hemorrhagic stroke within 60 days of drug initiation. Exposures: Treatment with tirzepatide compared with GLP-1 RA. Main Outcomes and Measures: The primary outcome was all-cause mortality, and secondary outcomes included major adverse cardiovascular events (MACEs), the composite of MACEs and all-cause mortality, kidney events, acute kidney injury, and major adverse kidney events. All outcomes were analyzed using Cox proportional hazards regression models. Results: There were 14 834 patients treated with tirzepatide (mean [SD] age, 55.4 [11.8] years; 8444 [56.9%] female) and 125 474 treated with GLP-1 RA (mean [SD] age, 58.1 [13.3] years; 67 474 [53.8%] female). After a median (IQR) follow-up of 10.5 (5.2-15.7) months, 95 patients (0.6%) in the tirzepatide group and 166 (1.1%) in the GLP-1 RA group died. Tirzepatide treatment was associated with lower hazards of all-cause mortality (adjusted hazard ratio [AHR], 0.58; 95% CI, 0.45-0.75), MACEs (AHR, 0.80; 95% CI, 0.71-0.91), the composite of MACEs and all-cause mortality (AHR, 0.76; 95% CI, 0.68-0.84), kidney events (AHR, 0.52; 95% CI, 0.37-0.73), acute kidney injury (AHR, 0.78; 95% CI, 0.70-0.88), and major adverse kidney events (AHR, 0.54; 95% CI, 0.44-0.67). Treatment with tirzepatide was associated with greater decreases in glycated hemoglobin (treatment difference, -0.34 percentage points; 95% CI, -0.44 to -0.24 percentage points) and body weight (treatment difference, -2.9 kg, 95% CI, -4.8 to -1.1 kg) compared with GLP-1 RA. An interaction test for subgroup analysis revealed consistent results stratified by estimated glomerular filtration rate, glycated hemoglobin level, body mass index, comedications, and comorbidities. Conclusions and Relevance: In this study, treatment with tirzepatide was associated with lower hazards of all-cause mortality, adverse cardiovascular events, acute kidney injury, and adverse kidney events compared with GLP-1 RA in patients with type 2 diabetes. These findings support the integration of tirzepatide into therapeutic strategies for this population.

Achieving normoglycaemia with tirzepatide: Post hoc exploratory analysis of the SURPASS J-mono and J-combo studies.

AIM: Normoglycaemia was achieved in a significant proportion of Japanese participants with type 2 diabetes in two phase 3 studies of tirzepatide. This post hoc exploratory analysis aimed to identify predictive factors associated with normoglycaemia achievement. MATERIALS AND METHODS: SURPASS J-mono and SURPASS J-combo study data were pooled for this analysis. Characteristics of participants in whom normoglycaemia [glycated haemoglobin (HbA1c) <5.7%] was achieved were summarized. Logistic regression analyses were performed with HbA1c <5.7% achievement as the target variable. RESULTS: Of 912 participants, normoglycaemia was achieved in 553 (60.6%) following 52 weeks of tirzepatide treatment. Overall, the mean (SD) age was 56.7 (10.6) years and mean diabetes duration was 7.7 (6.0) years, and 76% of participants were men. Mean (SD) change from baseline in HbA1c and bodyweight was -2.87% (0.95) versus -2.47% (1.1) and -10.30 (5.8) kg versus -3.75 (4.3) kg for participants in whom normoglycaemia was and was not reached, respectively. Multivariate regression analyses showed that lower baseline body mass index, shorter disease duration and lower baseline HbA1c were significantly associated with higher rates of normoglycaemia achievement (p = 0.009, p = 0.008, p < 0.001, respectively) as was a tirzepatide dose of 10 or 15 mg compared with 5 mg (p < 0.001). The highest percentage of participants in whom normoglycaemia (94%) was achieved were those with lower baseline HbA1c (<8%) and the greatest weight reduction (≥15%). CONCLUSIONS: Baseline HbA1c and body mass index, disease duration and the tirzepatide treatment group were shown to be predictive factors for achieving normoglycaemia. A lower baseline HbA1c was most strongly associated with normoglycaemia achievement.

The dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 receptor agonist tirzepatide effects on body weight evolution, adiponectin, insulin and leptin levels in the combination of obesity, type 2 diabetes and menopause in mice.

AIM: Tirzepatide (Tzp), a novel dual agonist glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1, is approved for treating insulin resistance and obesity, and menopausal women consuming a high-calorie diet are a target to study the Tzp effect. Therefore, we aimed to allometrically scale body weight (BW) in Tzp-treated obese diabetic menopausal mice. MATERIALS AND METHODS: Three-month-old C57BL/6 female mice had bilateral ovariectomy (Ovx) or a sham procedure and for 12 weeks were fed a control diet or a high-fat and high sucrose diet (n = 120/each group [control (C), obese diabetic (Od), Ovx (O), sham (S), Tzp (T)]). Tzp was subcutaneously administered (10 nmol/kg) or vehicle once a day for an additional 4 weeks. The analysis considered log-transformed data and the allometric equation log y = log a + b log x. RESULTS: Od and OdO showed more upward slopes than C and CO. In C, BW was non-allometric by T administration. Od and OdO showed slightly positive slopes (more prominent in OdO than Od). OdT and OdOT showed negative slopes, significant intercepts, and more robust Pearson coefficients than untreated ones. A potent drug effect was seen with BW allometric decline. Interactions between diet versus Ovx and diet versus Tzp affected weight gain. Diet versus Ovx versus Tzp affected food intake. CONCLUSIONS: A model was developed to show three usual factors observed in mature women. Notably, Tzp improved the metabolism and weight loss of OdO mice. Tzp-treated mice showed negative allometric BW across treatment time, which is a quantitative assessment that allows better comparison between results.

Bridging the gap between GLP1-receptor agonists and cardiovascular outcomes: evidence for the role of tirzepatide.

Tirzepatide is a new drug targeting glucagon-like peptide 1(GLP1) and gastric inhibitory polypeptide (GIP) receptors. This drug has demonstrated great potential in improving the clinical outcomes of patients with type 2 diabetes. It can lead to weight loss, better glycemic control, and reduced cardiometabolic risk factors. GLP1 receptor agonists have been proven effective antidiabetic medications with possible cardiovascular benefits. Even though they have been proven to reduce the risk of major adverse cardiovascular events, their effectiveness in treating heart failure is unknown. Unlike traditional GLP1 receptor agonists, tirzepatide is more selective for the GIP receptor, resulting in a more balanced activation of these receptors. This review article discusses the possible mechanisms tirzepatide may use to improve cardiovascular health. That includes the anti-inflammatory effect, the ability to reduce cell death and promote autophagy, and also its indirect effects through blood pressure, obesity, and glucose/lipid metabolism. Additionally, tirzepatide may benefit atherosclerosis and lower the risk of major adverse cardiac events. Currently, clinical trials are underway to evaluate the safety and efficacy of tirzepatide in patients with heart failure. Overall, tirzepatide's dual agonism of GLP1 and GIP receptors appears to provide encouraging cardiovascular benefits beyond glycemic control, offering a potential new therapeutic option for treating cardiovascular diseases and heart failure.

Tirzepatide against obesity and insulin-resistance: pathophysiological aspects and clinical evidence.

Obesity is a chronic, multifactorial disease in which accumulated excess body fat has a negative impact on health. Obesity continues to rise among the general population, resulting in an epidemic that shows no significant signs of decline. It is directly involved in development of cardiometabolic diseases, ischemic coronary heart disease peripheral arterial disease, heart failure, and arterial hypertension, producing global morbidity and mortality. Mainly, abdominal obesity represents a crucial factor for cardiovascular illness and also the most frequent component of metabolic syndrome. Recent evidence showed that Tirzepatide (TZP), a new drug including both Glucagon Like Peptide 1 (GLP-1) and Glucose-dependent Insulinotropic Polypeptide (GIP) receptor agonism, is effective in subjects with type 2 diabetes (T2D), lowering body weight, fat mass and glycated hemoglobin (HbA1c) also in obese or overweight adults without T2D. This review discusses the pathophysiological mechanisms and clinical aspects of TZP in treating obesity.

Molecular dynamics-guided optimization of BGM0504 enhances dual-target agonism for combating diabetes and obesity.

The dual activation of glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) has emerged as a promising therapeutic strategy for managing type 2 diabetes and obesity. Tirzepatide, a dual agonist peptide, has exhibited superior clinical efficacy in glycemic and weight control compared to selective GLP-1R agonists. Nevertheless, the structural basis of Tirzepatide's extended half-life, attributed to an acylation side chain on the parent peptide, raises questions regarding its partial agonistic activity. Employing molecular dynamics simulations, we explored the dynamic processes of peptide-receptor interactions. We uncovered a crucial salt bridge between parent peptide and GLP-1R/GIPR at K20, a feature not discernible in cryo-electron microscopy structures. Building upon these insights, we developed an optimization strategy based on the parent peptide which involved repositioning the acylation side chain. The results of both in vitro and in vivo experiments demonstrated that the optimized peptide has twofold to threefold increase in agonistic activity compared to Tirzepatide while maintaining its extended half-life in plasma. This led to the design of BGM0504, which proved to be more effective than its predecessor, Tirzepatide, in both laboratory and animal studies.

Poly(l-threonine-co-l-threonine Succinate) Thermogels for Sustained Release of Lixisenatide.

Negatively charged poly(l-Thr-co-l-Thr succinate) (PTTs) was developed as a new thermogel. Aqueous PTT solutions underwent thermogelation over a concentration range of 6.0-8.3 wt %. Dynamic light scattering, FTIR, 1H NMR, and COSY spectra revealed the partial strengthening of the ß-sheet conformation and the dehydration of PTTs during the transition. Extendin-4 was released from the PTTs thermogel with a large initial burst release, whereas positively charged lixisenatide significantly reduced its initial burst release to 25%, and up to 77% of the dose was released from the gel over 14 days. In vivo study revealed a high plasma concentration of lixisenatide over 5 days and hypoglycemic efficacy was observed for type II diabetic rats over 7-10 days. The biocompatible PTTs were degraded by subcutaneous enzymes. This study thus demonstrates an effective strategy for reducing the initial burst release of protein drugs from thermogels with the introduction of electrostatic interactions between the drug and the thermogel.

Effect of Dual Glucagon-Like Peptide 1/Glucose-Dependent Insulinotropic Polypeptide Receptor Agonist (Tirzepatide) versus Bariatric Surgery on Weight Loss and Nonalcoholic Fatty Liver Disease.

OBJECTIVES: Bariatric surgery is a well-established treatment for obesity and type 2 diabetes. Tirzepatide, a dual GIP/GLP-1 receptor agonist, has emerged as a promising therapy for type 2 diabetes. This study aimed to compare the effects of bariatric surgery, semaglutide (a GLP-1 receptor agonist), and tirzepatide in Sprague-Dawley rats fed a high-fat diet. METHODS: Rats were divided into surgery, semaglutide, and tirzepatide treatment groups, along with a control group (sham). Weight, oral glucose tolerance, and levels of metabolic markers were assessed, along with adipose and liver tissue analysis. RESULTS: Surgery led to a 15.5% weight reduction, while rats treated with semaglutide exhibited a 10.7% reduction. Tirzepatide treatment at various concentrations (10, 50, and 100 nmol/kg) resulted in weight reductions of 5.0%, 14.9%, and 17.7%, respectively, compared to the sham group. Metabolic analyte levels decreased in intervention groups compared to the sham group, indicating improved metabolic health and glucose tolerance. Adipose tissue weight and hepatic liver fat droplets decreased in the intervention groups. CONCLUSION: Bariatric surgery and tirzepatide treatment significantly improved metabolic parameters in obese rats. Tirzepatide, particularly at higher concentrations, showed pronounced improvements compared to surgery and semaglutide. These findings suggest that high doses of tirzepatide could be explored as an alternative to bariatric surgery for the treatment of obesity.

Semaglutide vs Tirzepatide for Weight Loss in Adults With Overweight or Obesity.

Importance: Although tirzepatide and semaglutide were shown to reduce weight in randomized clinical trials, data from head-to-head comparisons in populations with overweight or obesity are not yet available. Objective: To compare on-treatment weight loss and rates of gastrointestinal adverse events (AEs) among adults with overweight or obesity receiving tirzepatide or semaglutide labeled for type 2 diabetes (T2D) in a clinical setting. Design, Setting, and Participants: In this cohort study, adults with overweight or obesity receiving semaglutide or tirzepatide between May 2022 and September 2023 were identified using electronic health record (EHR) data linked to dispensing information from a collective of US health care systems. On-treatment weight outcomes through November 3, 2023, were assessed. Adults with overweight or obesity and regular care in the year before initiation, no prior glucagon-like peptide 1 receptor agonist receptor agonist use, a prescription within 60 days prior to initiation, and an available baseline weight were identified. The analysis was completed on April 3, 2024. Exposures: Tirzepatide or semaglutide in formulations labeled for T2D, on or off label. Main Outcomes and Measures: On-treatment weight change in a propensity score-matched population, assessed as hazard of achieving 5% or greater, 10% or greater, and 15% or greater weight loss, and percentage change in weight at 3, 6, and 12 months. Hazards of gastrointestinal AEs were compared. Results: Among 41 222 adults meeting the study criteria (semaglutide, 32 029; tirzepatide, 9193), 18 386 remained after propensity score matching. The mean (SD) age was 52.0 (12.9) years, 12 970 were female (70.5%), 14 182 were white (77.1%), 2171 Black (11.8%), 354 Asian (1.9%), 1679 were of other or unknown race, and 9563 (52.0%) had T2D. The mean (SD) baseline weight was 110 (25.8) kg. Follow-up was ended by discontinuation for 5140 patients (55.9%) receiving tirzepatide and 4823 (52.5%) receiving semaglutide. Patients receiving tirzepatide were significantly more likely to achieve weight loss (≥5%; hazard ratio [HR], 1.76, 95% CI, 1.68, 1.84; ≥10%; HR, 2.54; 95% CI, 2.37, 2.73; and ≥15%; HR, 3.24; 95% CI, 2.91, 3.61). On-treatment changes in weight were larger for patients receiving tirzepatide at 3 months (difference, -2.4%; 95% CI -2.5% to -2.2%), 6 months (difference, -4.3%; 95% CI, -4.7% to -4.0%), and 12 months (difference, -6.9%; 95% CI, -7.9% to -5.8%). Rates of gastrointestinal AEs were similar between groups. Conclusions and Relevance: In this population of adults with overweight or obesity, use of tirzepatide was associated with significantly greater weight loss than semaglutide. Future study is needed to understand differences in other important outcomes.

Achievement of normoglycemia with tirzepatide in type 2 diabetes mellitus: A step closer to drug-induced diabetes remission?

We sought to determine whether treatment with tirzepatide in type 2 diabetes mellitus (T2DM) patients can increase the odds for achieving normoglycemia, compatible with glycated hemoglobin levels lower than 5.7 %. We demonstrated that treatment with tirzepatide versus control increased the odds for achievement of normoglycemia by >16 times.

NPYR modulation: Potential for the next major advance in obesity and type 2 diabetes management?

The approval of the glucagon-like peptide 1 (GLP-1) mimetics semaglutide and liraglutide for management of obesity, independent of type 2 diabetes (T2DM), has initiated a resurgence of interest in gut-hormone derived peptide therapies for the management of metabolic diseases, but side-effect profile is a concern for these medicines. However, the recent approval of tirzepatide for obesity and T2DM, a glucose-dependent insulinotropic polypeptide (GIP), GLP-1 receptor co-agonist peptide therapy, may provide a somewhat more tolerable option. Despite this, an increasing number of non-incretin alternative peptides are in development for obesity, and it stands to reason that other hormones will take to the limelight in the coming years, such as peptides from the neuropeptide Y family. This narrative review outlines the therapeutic promise of the neuropeptide Y family of peptides, comprising of the 36 amino acid polypeptides neuropeptide Y (NPY), peptide tyrosine-tyrosine (PYY) and pancreatic polypeptide (PP), as well as their derivatives. This family of peptides exerts a number of metabolically relevant effects such as appetite regulation and can influence pancreatic beta-cell survival. Although some of these actions still require full translation to the human setting, potential therapeutic application in obesity and type 2 diabetes is conceivable. However, like GLP-1 and GIP, the endogenous NPY, PYY and PP peptide forms are subject to rapid in vivo degradation and inactivation by the serine peptidase, dipeptidyl-peptidase 4 (DPP-4), and hence require structural modification to prolong circulating half-life. Numerous protective modification strategies are discussed in this regard herein, alongside related impact on biological activity profile and therapeutic promise.

Does glucose-dependent insulinotropic polypeptide receptor blockade as well as agonism have a role to play in management of obesity and diabetes?

Recent approval of the dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist, tirzepatide, for the management of type 2 diabetes mellitus (T2DM) has reinvigorated interest in exploitation of GIP receptor (GIPR) pathways as a means of metabolic disease management. However, debate has long surrounded the use of the GIPR as a therapeutic target and whether agonism or antagonism is of most benefit in management of obesity/diabetes. This controversy appears to be partly resolved by the success of tirzepatide. However, emerging studies indicate that prolonged GIPR agonism may desensitise the GIPR to essentially induce receptor antagonism, with this phenomenon suggested to be more pronounced in the human than rodent setting. Thus, deliberation continues to rage in relation to benefits of GIPR agonism vs antagonism. That said, as with GIPR agonism, it is clear that the metabolic advantages of sustained GIPR antagonism in obesity and obesity-driven forms of diabetes can be enhanced by concurrent GLP-1 receptor (GLP-1R) activation. This narrative review discusses various approaches of pharmacological GIPR antagonism including small molecule, peptide, monoclonal antibody and peptide-antibody conjugates, indicating stage of development and significance to the field. Taken together, there is little doubt that interesting times lie ahead for GIPR agonism and antagonism, either alone or when combined with GLP-1R agonists, as a therapeutic intervention for the management of obesity and associated metabolic disease.

Tirzepatide modulates the regulation of adipocyte nutrient metabolism through long-acting activation of the GIP receptor.

Tirzepatide, a glucose-dependent insulinotropic polypeptide/glucagon-like peptide 1 receptor (GIPR/GLP-1R) agonist, has, in clinical trials, demonstrated greater reductions in glucose, body weight, and triglyceride levels compared with selective GLP-1R agonists in people with type 2 diabetes (T2D). However, cellular mechanisms by which GIPR agonism may contribute to these improved efficacy outcomes have not been fully defined. Using human adipocyte and mouse models, we investigated how long-acting GIPR agonists regulate fasted and fed adipocyte functions. In functional assays, GIPR agonism enhanced insulin signaling, augmented glucose uptake, and increased the conversion of glucose to glycerol in a cooperative manner with insulin; however, in the absence of insulin, GIPR agonists increased lipolysis. In diet-induced obese mice treated with a long-acting GIPR agonist, circulating triglyceride levels were reduced during oral lipid challenge, and lipoprotein-derived fatty acid uptake into adipose tissue was increased. Our findings support a model for long-acting GIPR agonists to modulate both fasted and fed adipose tissue function differentially by cooperating with insulin to augment glucose and lipid clearance in the fed state while enhancing lipid release when insulin levels are reduced in the fasted state.

Ameliorative effect of lixisenatide on diabetic cardiovascular damage and its enhancement via ticagrelor co-administration in rats: possible role of eNOS and NrF2 /HO-1 signaling.

In this study, we hypothesized that lixisenatide (LIX) and ticagrelor (TIC) could have a protective effect against type 2 diabetes mellitus (T2DM)-induced vascular damage. Furthermore, we explored the possible additional protective effect of co-administering LIX and TIC in the treatment regimen. Methods: 50 male rats were divided into five groups, each comprising 10 rats: C (control), D (T2DM rats), D + LIX (T2DM rats treated with LIX for 4 weeks), D + TIC (T2DM rats treated with TIC for 4 weeks), and D + LIX + TIC (T2DM rats treated with LIX + TIC for 4 weeks). Results: The D group showed an increase in body weight, blood glucose, hemostatic model assessment for insulin resistance (HOMA-IR), aorta reactive oxygen species (ROS), and nuclear factor kappa B (NF-κ B), along with a reduction in serum insulin, aorta superoxide dismutase (SOD), glutathione reduced (GSH), nuclear factor erythroid-2 (NrF2), hemeoxygenase-1 (HO-1), and endothelial nitric oxide synthase (eNOS). Deterioration in the aorta histopathological condition, coupled with a noticeable impairment in vascular reactivity compared to the C group, was observed. A single administration of LIX showed a reduction in body weight, blood glucose, HOMA-IR, aorta ROS, and NF-κ B, accompanied by an increase in serum insulin, aorta SOD, GSH, NrF2, HO-1, and eNOS. Amelioration in the aorta histopathological condition and improved vascular reactivity compared to the D group were reported. Similarly, a single administration of TIC showed a reduction in aorta ROS and NF-κ B, along with an increase in aorta SOD, GSH, NrF2, HO-1, and eNOS. A slight amelioration was detected in the aorta histopathological condition, with improved vascular reactivity compared to the D group. The combined administration of LIX and TIC showed a reduction in aorta ROS and NF-κ B, along with an increase in aorta GSH, SOD, HO-1, and eNOS. This was combined with evident amelioration in the aorta histopathological condition and noticeable improvement in vascular reactivity compared to the single treatment with either LIX or TIC group. Conclusion: The present study introduces clear evidence that the administration of LIX and TIC can improve metabolic and vascular complications of T2DM through modulating eNOS and NrF2 /HO-1 signaling. The combined administration of LIX and TIC produced more significant effects than a single treatment.