GLP-1 receptor agonist, liraglutide, ameliorates hepatosteatosis induced by anti-CD3 antibody in female mice

Comparative outcomes of systemic diseases in people with type 2 diabetes, or obesity alone treated with and without GLP-1 receptor agonists: a retrospective cohort study from the Global Collaborative Network : Author list

BACKGROUND

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are increasingly used to manage type 2 diabetes (T2D) and obesity. Despite their recognized benefits in glycemic control and weight management, their impact on broader systemic has been less explored.

OBJECTIVE

This study aimed to evaluate the impact of GLP-1RAs on a variety of systemic diseases in people with T2D or obesity.

METHODS

We conducted a retrospective cohort study using data from the Global Collaborative Network, accessed through the TriNetX analytics platform. The study comprised two primary groups: individuals with T2D and those with obesity. Each group was further divided into subgroups based on whether they received GLP-1RA treatment or not. Data were analyzed over more than a 5-year follow-up period, comparing incidences of systemic diseases; systemic lupus erythematosus (SLE), systemic sclerosis (SS), rheumatoid arthritis (RA), ulcerative colitis (UC), crohn's disease (CD), alzheimer's disease (AD), parkinson's disease (PD), dementia, bronchial asthma (BA), osteoporosis, and several cancers.

RESULTS

In the T2D cohorts, GLP-1RA treatment was associated with significantly lower incidences of several systemic and metabolic conditions as compared to those without GLP-1RA, specifically, dementia (Risk Difference (RD): -0.010, p < 0.001), AD (RD: -0.003, p < 0.001), PD (RD: -0.002, p < 0.001), and pancreatic cancer (RD: -0.003, p < 0.001). SLE and SS also saw statistically significant reductions, though the differences were minor in magnitude (RD: -0.001 and - 0.000 respectively, p < 0.001 for both). Conversely, BA a showed a slight increase in risk (RD: 0.002, p < 0.001).

CONCLUSIONS

GLP-1RAs demonstrate potential benefits in reducing the risk of several systemic conditions in people with T2D or obesity. Further prospective studies are needed to confirm these effects fully and understand the mechanisms.

Exploring Liraglutide in Lithium-Pilocarpine-Induced Temporal Lobe Epilepsy Model in Rats: Impact on Inflammation, Mitochondrial Function, and Behavior

Background/Objectives: Glucagon-like peptide-1 receptor agonists such as liraglutide are known for their neuroprotective effects in neurodegenerative disorders, but their role in temporal lobe epilepsy (TLE) remains unclear. We aimed to investigate the effects of liraglutide on several biological processes, including inflammation, antioxidant defense mechanisms, mitochondrial dynamics, and function, as well as cognitive and behavioral changes in the TLE model. Methods: Low-dose, repeated intraperitoneal injections of lithium chloride-pilocarpine hydrochloride were used to induce status epilepticus (SE) in order to develop TLE in rats. Fifty-six male Sprague Dawley rats were subjected and allocated to the groups. The effects of liraglutide on inflammatory markers (NLRP3, Caspase-1, and IL-1β), antioxidant pathways (Nrf-2 and p-Nrf-2), and mitochondrial dynamics proteins (Pink1, Mfn2, and Drp1) were evaluated in hippocampal tissues via a Western blot. Mitochondrial function in peripheral blood mononuclear cells (PBMCs) was examined using flow cytometry. Cognitive-behavioral outcomes were assessed using the open-field, elevated plus maze, and Morris water maze tests. Results: Our results showed that liraglutide modulates NLRP3-mediated inflammation, reduces oxidative stress, and triggers antioxidative pathways through Nrf2 in SE-induced rats. Moreover, liraglutide treatment restored Pink1, Mfn2, and Drp1 levels in SE-induced rats. Liraglutide treatment also altered the mitochondrial function of PBMCs in both healthy and epileptic rats. This suggests that treatment can modulate mitochondrial dynamics and functions in the brain and periphery. Furthermore, in the behavioral aspect, liraglutide reversed the movement-enhancing effect of epilepsy. Conclusions: This research underscores the potential of GLP-1RAs as a possibly promising therapeutic strategy for TLE.

Emerging mechanisms of obesity-associated immune dysfunction

Obesity is associated with a wide range of complications, including type 2 diabetes mellitus, cardiovascular disease, hypertension and nonalcoholic fatty liver disease. Obesity also increases the incidence and progression of cancers, autoimmunity and infections, as well as lowering vaccine responsiveness. A unifying concept across these differing diseases is dysregulated immunity, particularly inflammation, in response to metabolic overload. Herein, we review emerging mechanisms by which obesity drives inflammation and autoimmunity, as well as impairing tumour immunosurveillance and the response to infections. Among these mechanisms are obesity-associated changes in the hormones that regulate immune cell metabolism and function and drive inflammation. The cargo of extracellular vesicles derived from adipose tissue, which controls cytokine secretion from immune cells, is also dysregulated in obesity, in addition to impairments in fatty acid metabolism related to inflammation. Furthermore, an imbalance exists in obesity in the biosynthesis and levels of polyunsaturated fatty acid-derived oxylipins, which control a range of outcomes related to inflammation, such as immune cell chemotaxis and cytokine production. Finally, there is a need to investigate how obesity influences immunity using innovative model systems that account for the heterogeneous nature of obesity in the human population.

Multifaceted roles of T cells in obesity and obesity-related complications: A narrative review

Obesity is characterized by chronic low-grade inflammatory responses in the adipose tissue, accompanied by pronounced insulin resistance and metabolic anomalies. It affects almost all body organs and eventually leads to diseases such as fatty liver disease, type 2 diabetes mellitus, and atherosclerosis. Recently, T cells have emerged as interesting therapeutic targets because the dysfunction of T cells and their cytokines in the adipose tissue is implicated in obesity-induced inflammation and their complicated onset. Although several recent narrative reviews have provided a brief overview of related evidence in this area, they have mainly focused on either obesity-associated T cell metabolism or modulation of T cell activation in obesity. Moreover, at present, no published review has reported on the multifaceted roles of T cells in obesity and obesity-related complications, even though there has been a significant increase in studies on this topic since 2019. Therefore, this narrative review aims to comprehensively summarize current advances in the mechanistic roles of T cells in the development of obesity and its related complications. Further, we aim to discuss relevant drugs for weight loss as well as the contradictory role of T cells in the same disease so as to highlight key findings regarding this topic and provide a valid basis for future treatment strategies.

GLP-1 receptor agonist as a modulator of innate immunity

Glucagon-like peptide-1 (GLP-1) is a 30-amino acid hormone secreted by L cells in the distal ileum, colon, and pancreatic α cells, which participates in blood sugar regulation by promoting insulin release, reducing glucagon levels, delaying gastric emptying, increasing satiety, and reducing appetite. GLP-1 specifically binds to the glucagon-like peptide-1 receptor (GLP-1R) in the body, directly stimulating the secretion of insulin by pancreatic β-cells, promoting proliferation and differentiation, and inhibiting cell apoptosis, thereby exerting a glycemic lowering effect. The glycemic regulating effect of GLP-1 and its analogues has been well studied in human and murine models in the circumstance of many diseases. Recent studies found that GLP-1 is able to modulate innate immune response in a number of inflammatory diseases. In the present review, we summarize the research progression of GLP-1 and its analogues in immunomodulation and related signal pathways.

Effects of glucagon-like peptide-1 analog liraglutide on the systemic inflammation in high-fat-diet-induced mice

OBJECTIVE

Metabolic syndrome is a chronic-metabolic disease caused by a variety of factors, including high peripheral blood insulin levels and insulin resistance. It has been reported that GLP-1 could regulate insulin resistance. It is not known whether and how GLP-1 protects from fat-induced inflammation and immune changes. We investigated if GLP-1 alters the populations of fat-induced inflammation and immune cells and the related mechanism.

METHODS

We obtained obese C57BL/6J mice by feeding them high-fat food, then treated the obese mice with GLP-1+ high-fat diet (G + Hi), normal chow diet (Nor), or high-fat diet (Hi) (n = 20 for each group) for 8 weeks. The GLP-1 receptor-/- B6 group were fed with HFD for 8 weeks (GLP-1R KO + Hi). In vivo and in vitro experiments were conducted on mice immune cells to investigate the effects of GLP-1 on the changes of the immune components and functions in obesity.

RESULTS

We found that GLP-1 could efficiently change the CD4+ T subsets and level of cytokines in high-fat-induced mice by GLP-1 receptor. Further, these changes were correlated with a reduction in fat content and serum lipid level. Interestingly, GLP-1 could enhance the function of Tregs in vitro.

CONCLUSION

Our data showed that GLP-1 has an important role in shaping the CD4+ T population in high-fat-diet-induced mice by GLP-1 receptor, possibly providing a new target for the treatment of metabolic syndrome.

Identification of therapeutic effect of glucagon-like peptide 1 in the treatment of STZ-induced diabetes mellitus in rats by restoring the balance of intestinal flora

OBJECTIVE

The objective of this study was to identify the therapeutic effect and the underlying mechanism of glucagon-like peptide 1 (GLP-1) in the treatment of STZ-induced diabetes mellitus (DM).

METHODS

Mice were treated with STZ to establish an animal model of DM, which was further treated with a GLP-1 receptor agonist. Subsequently, the status of glucose, insulin, nitric oxide, inflammatory and oxidative factors was evaluated and compared among Sham, STZ, and STZ + GLP-1 groups. In addition, the intestinal flora spectrum in each group was also evaluated.

RESULTS

In this study, it was found that the administration of STZ increased the level of glucose and glycosylated hemoglobin but reduced the level of insulin. It was also found that the levels of inflammation and oxidative stress in STZ-induced DM were both enhanced, as evidenced by a decreased level of catalase, superoxide dismutase, glutathione peroxidase, as well as increased levels of malonyldialdehyde, interleukin-1β (IL-1β), and IL-6. Meanwhile, the expression of nitric oxide, a factor associated with both oxidative stress and inflammation, was also suppressed in STZ-induced DM. More importantly, the imbalance of intestinal flora was observed in STZ-induced DM, as shown by a decreased level of both total bacteria and that of some strains including Clostridium, Bacteroides, Lactobacilli, and Bifidobacteria.

CONCLUSION

In summary, the findings of this study confirmed the antihyperglycemic effect of GLP-1 and demonstrated that the therapeutic effect of GLP-1 in the treatment of STZ-induced DM was mediated, at least partially, by its ability to restore the balance of intestinal flora.