Empagliflozin and Dulaglutide are Effective against Obesity-induced Airway Hyperresponsiveness and Fibrosis in A Murine Model

Impact of obesity on airway remodeling in asthma: pathophysiological insights and clinical implications

The prevalence of obesity among asthma patients has surged in recent years, posing a significant risk factor for uncontrolled asthma. Beyond its impact on asthma severity and patients' quality of life, obesity is associated with reduced lung function, increased asthma exacerbations, hospitalizations, heightened airway hyperresponsiveness, and elevated asthma-related mortality. Obesity may lead to metabolic dysfunction and immune dysregulation, fostering chronic inflammation characterized by increased pro-inflammatory mediators and adipocytokines, elevated reactive oxygen species, and reduced antioxidant activity. This chronic inflammation holds the potential to induce airway remodeling in individuals with asthma and obesity. Airway remodeling encompasses structural and pathological changes, involving alterations in the airway's epithelial and subepithelial layers, hyperplasia and hypertrophy of airway smooth muscle, and changes in airway vascularity. In individuals with asthma and obesity, airway remodeling may underlie heightened airway hyperresponsiveness and increased asthma severity, ultimately contributing to the development of persistent airflow limitation, declining lung function, and a potential increase in asthma-related mortality. Despite efforts to address the impact of obesity on asthma outcomes, the intricate mechanisms linking obesity to asthma pathophysiology, particularly concerning airway remodeling, remain incompletely understood. This comprehensive review discusses current research investigating the influence of obesity on airway remodeling, to enhance our understanding of obesity's role in the context of asthma airway remodeling.

Effect of Semaglutide and Empagliflozin on Pulmonary Structure and Proteomics in Obese Mice

Objective

This study utilized proteomics to investigate changes in protein expression associated with lung health in obese mice exposed to semaglutide and empagliflozin through a high-fat diet.

Methods

Twenty-eight male C57BL/6JC mice were randomly assigned to two groups: a control diet group (n = 7) and a high-fat diet group (n = 21). The HFD group was further divided into three groups: HFD group (n = 7), Sema group (n = 7), and Empa group (n = 7). Post-treatment, mice underwent assessments including glucose tolerance, lipids, oxidative stress markers, body weight, lung weight, and structure. Proteomics identified differentially expressed proteins (DEPs) in lung tissue, and bioinformatics analyzed the biological processes and functions of these proteins.

Results

Semaglutide and empagliflozin significantly attenuated obesity-induced hyperglycemia, abnormal lipid metabolism, oxidative stress response, and can decrease alveolar wall thickness, enlarge alveolar lumen, and reduce collagen content in lung tissue. Both medications also attenuated lung elastic fibre cracking and disintegration. In the HFD/NCD group, there were 66 DEPs, comprising 30 proteins that were increased and 36 that were decreased. Twenty-three DEPs overlapped between Sema/HFD and Empa/HFD, with 11 up-regulated and 12 down-regulated simultaneously. After analysing DEPs in different groups, four proteins - LYVE1, BRAF, RGCC, and CHMP5 - were all downregulated in the HFD group and upregulated by semaglutide and empagliflozin treatment.

Conclusion

This study demonstrates that obesity induced by a high-fat diet causes a reduction in the expression of LYVE1, BRAF, RGCC, and CHMP5 proteins, potentially affecting lung function and structure in mice. Significantly, the administration of semaglutide and empagliflozin elevates the levels of these proteins, potentially offering therapeutic benefits against lung injury caused by obesity. Merging semaglutide with empagliflozin may exert a more pronounced impact.

The anti-inflammatory and immunological properties of SGLT-2 inhibitors

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT-2i) are antidiabetic oral drugs that act on proximal renal tubules promoting renal glucose excretion. Although SGLT-2i belong to the class of hypoglycemic agents, in the last years great interest has emerged in studying their pleiotropic effects, beyond their ability to lower glucose levels.

PURPOSE

In this review we are describing the anti-inflammatory and immunological properties of SGLT-2i; furthermore, we are addressing how the mechanisms associated with the aforementioned anti-inflammatory properties may contribute to the beneficial effects of SGLT-2i in diabetes.

METHODS

A systematic search was undertaken for studies related the properties of SGLT-2i in reducing the inflammatory milieu of acute and chronic disease by acting on the immune system, independently by glycemia.

RESULTS

Recently, some data described the anti-inflammatory and immunological properties of SGLT-2 in both pre-clinical and clinical studies. Numerous data confirmed the cardio- and -renal protective effects of SGLT-2i in patients with heart failure and kidney diseases, with or without diabetes.

CONCLUSIONS

SGLT-2i are promising drugs with anti-inflammatory and immunological properties. Despite the mechanism of action of SGLT-2i is not fully understood, these drugs demonstrated anti-inflammatory effects, which may help in keeping under control the variety of complications associated with diabetes.

Empagliflozin Ameliorates Bleomycin-Induced Pulmonary Fibrosis in Rats by Modulating Sesn2/AMPK/Nrf2 Signaling and Targeting Ferroptosis and Autophagy

Pulmonary fibrosis (PF) is a life-threatening disorder that severely disrupts normal lung architecture and function, resulting in severe respiratory failure and death. It has no definite treatment. Empagliflozin (EMPA), a sodium-glucose cotransporter 2 (SGLT2) inhibitor, has protective potential in PF. However, the mechanisms underlying these effects require further elucidation. Therefore, this study aimed to evaluate the ameliorative effect of EMPA against bleomycin (BLM)-induced PF and the potential mechanisms. Twenty-four male Wister rats were randomly divided into four groups: control, BLM treated, EMPA treated, and EMPA+BLM treated. EMPA significantly improved the histopathological injuries illustrated by both hematoxylin and eosin and Masson's trichrome-stained lung tissue sections, as confirmed by electron microscopic examination. It significantly reduced the lung index, hydroxyproline content, and transforming growth factor β1 levels in the BLM rat model. It had an anti-inflammatory effect, as evidenced by a decrease in the inflammatory cytokines' tumor necrosis factor alpha and high mobility group box 1, inflammatory cell infiltration into the bronchoalveolar lavage fluid, and the CD68 immunoreaction. Furthermore, EMPA mitigated oxidative stress, DNA fragmentation, ferroptosis, and endoplasmic reticulum stress, as evidenced by the up-regulation of nuclear factor erythroid 2-related factor expression, heme oxygenase-1 activity, glutathione peroxidase 4 levels, and a decrease in C/EBP homologous protein levels. This protective potential could be explained on the basis of autophagy induction via up-regulating lung sestrin2 expression and the LC3 II immunoreaction observed in this study. Our findings indicated that EMPA protected against BLM-induced PF-associated cellular stress by enhancing autophagy and modulating sestrin2/adenosine monophosphate-activated protein kinase/nuclear factor erythroid 2-related factor 2/heme oxygenase 1 signaling.

Vertical sleeve gastrectomy associates with airway hyperresponsiveness in a murine model of allergic airway disease and obesity

Introduction

Asthma is a chronic airway inflammatory disease marked by airway inflammation, remodeling and hyperresponsiveness to allergens. Allergic asthma is normally well controlled through the use of beta-2-adrenergic agonists and inhaled corticosteroids; however, a subset of patients with comorbid obesity experience resistance to currently available therapeutics. Patients with asthma and comorbid obesity are also at a greater risk for severe disease, contributing to increased risk of hospitalization. Bariatric surgery improves asthma control and airway hyperresponsiveness in patients with asthma and comorbid obesity, however, the underlying mechanisms for these improvements remain to be elucidated. We hypothesized that vertical sleeve gastrectomy (VSG), a model of metabolic surgery in mice, would improve glucose tolerance and airway inflammation, resistance, and fibrosis induced by chronic allergen challenge and obesity.

Methods

Male C57BL/6J mice were fed a high fat diet (HFD) for 13 weeks with intermittent house dust mite (HDM) allergen administration to induce allergic asthma, or saline as control. At week 11, a subset of mice underwent VSG or Sham surgery with one week recovery. A separate group of mice did not undergo surgery. Mice were then challenged with HDM or saline along with concurrent HFD feeding for 1-1.5 weeks before measurement of lung mechanics and harvesting of tissues, both of which occurred 24 hours after the final HDM challenge. Systemic and pulmonary cytokine profiles, lung histology and gene expression were analyzed.

Results

High fat diet contributed to increased body weight, serum leptin levels and development of glucose intolerance for both HDM and saline treatment groups. When compared to saline-treated mice, HDM-challenged mice exhibited greater weight gain. VSG improved glucose tolerance in both saline and HDM-challenged mice. HDM-challenged VSG mice exhibited an increase in airway hyperresponsiveness to methacholine when compared to the non-surgery group.

Discussion

The data presented here indicate increased airway hyperresponsiveness in allergic mice undergoing bariatric surgery.

Association of adverse respiratory events with sodium-glucose cotransporter 2 inhibitors versus dipeptidyl peptidase 4 inhibitors among patients with type 2 diabetes in South Korea: a nationwide cohort study

BACKGROUND

Impaired respiratory function remains underrecognized in patients with type 2 diabetes (T2D), despite common pulmonary impairment. Meanwhile, there is little data available on the respiratory effects of sodium glucose cotransporter 2 inhibitors (SGLT2i). Hence, we examined the association between SGLT2i use and the risk of adverse respiratory events in a real-world setting.

METHODS

We conducted a population-based, nationwide cohort study using an active-comparator new-user design and nationwide claims data of South Korea from January 2015 to December 2020. Among individuals aged 18 years or older, propensity score matching was done to match each new user of SGLT2is with dipeptidyl peptidase 4 inhibitors (DPP4is), with patients followed up according to an as-treated definition. The primary outcome was respiratory events, a composite endpoint of acute pulmonary edema, acute respiratory distress syndrome (ARDS), pneumonia, and respiratory failure. Secondary outcomes were the individual components of the primary outcome and in-hospital death. Cox models were used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

Of 205,534 patient pairs in the propensity score matched cohort, the mean age of the entire cohort was 53.8 years and 59% were men, with a median follow-up of 0.66 years; all baseline covariates achieved balance between the two groups. Incidence rates for overall respiratory events were 4.54 and 7.54 per 1000 person-years among SGLT2i and DPP4i users, respectively, corresponding to a rate difference of 3 less events per 1000 person-years (95% CI - 3.44 to - 2.55). HRs (95% CIs) were 0.60 (0.55 to 0.64) for the composite respiratory endpoint, 0.35 (0.23 to 0.55) for acute pulmonary edema, 0.44 (0.18 to 1.05) for ARDS, 0.61 (0.56 to 0.66) for pneumonia, 0.49 (0.31 to 0.76) for respiratory failure, and 0.46 (0.41 to 0.51) for in-hospital death. Similar trends were found across individual SGLT2is, subgroup analyses of age, sex, history of comorbidities, and a range of sensitivity analyses.

CONCLUSIONS

These findings suggest a lower risk of adverse respiratory events associated with patients with T2D initiating SGLT2is versus DPP4is. This real-world evidence helps inform patients, clinicians, and guideline writers regarding the respiratory effects of SGLT2i in routine practice.

Reno-protective effects of GLP-1 receptor agonist and anti-platelets in experimentally induced diabetic kidney disease in male albino rats

Objectives

The prevalence of chronic kidney disease in diabetics is progressively increasing with an increased risk of fatal complications.

Materials and Methods

Sixty male albino rats were used in the study, and type 2 diabetes mellitus were induced. Diabetic rats were divided randomly into 5 groups, the control diabetic group and 4 treated groups were treated with metformin (group3), dulaglutide (group 4), metformin & cilostazol (group 5), and the last group was treated with dulaglutide & cilostazol (group 6). At the end of the experiment, the weight of rats and systolic blood pressure were estimated. After overnight fasting, the serum levels of blood glucose, lipid profile, and kidney function were measured. After scarification, gene expression of eNOS and NFKB in kidney tissue were estimated and kidney tissues were examined for histopathology.

Results

Diabetic rats showed a significant increase in body weight, blood pressure, serum blood glucose, lipid profile, and impaired kidney function. Metformin and dulaglutide are associated with a significant decrease in blood pressure, blood glucose level, serum lipid profile, and improved kidney function. These changes are associated with a significant increase in anti-oxidative markers, and decreased inflammatory and fibrotic markers, especially with the addition of cilostazol.

Conclusion

Metformin and dulaglutide have been shown to ameliorate kidney damage in diabetics by stimulating the anti-oxidant defense system, normalizing kidney functional parameters, and improving histopathological changes. The addition of cilostazol to metformin or dulaglutide increased some of their anti-oxidants and anti-inflammatory properties.

Long-Term Activation of Glucagon-like peptide-1 receptor by Dulaglutide Prevents Diabetic Heart Failure and Metabolic Remodeling in Type 2 Diabetes

Background Mechanistic insights of glucagon-like peptide-1 receptor agonists remain incompletely identified, despite the efficacy in heart failure observed in clinical trials. Here, we evaluated the effects of dulaglutide on heart complications and illuminated its underlying mechanism. Methods and Results We used mice with high-fat diet (HFD)/streptozotocin-induced type 2 diabetes to investigate the effects of dulaglutide upon diabetic cardiac dysfunction. After the onset of diabetes, control and diabetic mice were injected subcutaneously with either dulaglutide (type 2 diabetes-dulaglutide and control-dulaglutide groups) or vehicle (type 2 diabetes-vehicle and control-vehicle groups) for 8 weeks. Subsequently, heart characteristics, cardiometabolic profile and mitochondrial morphology and function were evaluated. Also, we analyzed the effects of dulaglutide on neonatal rat ventricular myocytes treated with high glucose plus palmitic acid. In addition, wild type and AMP-activated protein kinase α2 mutant mice were used to evaluate the underlying mechanism. In type 2 diabetes mouse model, dulaglutide ameliorated insulin resistance, improved glucose tolerance, reduced hyperlipidemia, and promoted fatty acid use in the myocardium. Dulaglutide treatment functionally attenuated cardiac remodeling and dysfunction and promoted metabolic reprogramming in diabetic mice. Furthermore, dulaglutide improved mitochondria fragmentation in myocytes, and simultaneously reinstated mitochondrial morphology and function in diabetic hearts. We also found that dulaglutide preserved AMP-activated protein kinase α2-dependent mitochondrial homeostasis, and the protective effects of dulaglutide on diabetic heart was almost abated by AMP-activated protein kinase α2 knockout. Conclusions Dulaglutide prevents diabetic heart failure and favorably affects myocardial metabolic remodeling by impeding mitochondria fragmentation, and we suggest a potential strategy to develop a long-term activation of glucagon-like peptide-1 receptor-based therapy to treat diabetes associated cardiovascular complications.

Application of glucagon-like peptide-1 receptor antagonists in fibrotic diseases

Fibrosis can occur in various organs, leading to structural destruction, dysfunction, and even organ failure. Hence, organ fibrosis is being actively researched worldwide. Glucagon-like peptide-1 (GLP-1), a naturally occurring hormone, binds to a G-protein-coupled receptor widely distributed in the pancreas, kidney, lung, heart, gastrointestinal tract, and other organs. Synthetic GLP-1 analogs can be used as GLP-1 receptor agonists (GLP-1RAs) for treating diabetes mellitus. In recent years, GLP-1RAs have also been found to exert anti-inflammatory, antioxidant, and cardiovascular protective effects. GLP-1RAs have also been shown to inhibit fibrosis of solid organs, such as the lung, heart, liver, and kidney. In this review, we discuss the advancements in research on the role of GLP-1RAs in the fibrosis of the heart, lung, liver, kidney, and other organs to obtain new clues for treating organ fibrosis.

The impact of SGLT2 inhibitors on inflammation: A systematic review and meta-analysis of studies in rodents

BACKGROUND

Inhibition of sodium-glucose cotransporter-2 (SGLT2) has received remarkable attention due to the beneficial effects observed in diabetes mellitus, heart failure, and kidney disease. Several mechanisms have been proposed for these pleiotropic effects, including anti-inflammatory ones. Our systematic review and meta-analysis aimed to assess the effect of SGLT2 inhibition on inflammatory markers in experimental models.

METHODS

A literature search was conducted to detect studies examining the effect of SGLT2 inhibitors on inflammatory markers [interleukin-6 (IL-6), C reactive protein (CRP), tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1)]. Consequently, a meta-analysis of the included studies was performed, assessing the differences in the levels of the inflammatory markers between the treatment groups as its primary outcome. Moreover, risk of bias, sensitivity analysis and publication bias were evaluated.

RESULTS

The systematic literature review yielded 30 studies whose meta-analysis suggested that treatment with an SGLT2 inhibitor resulted in decreases of IL-6 [standardized mean difference (SMD): -1.56, 95% CI -2.06 to -1.05), CRP (SMD: -2.17, 95% CI -2.80 to -1.53), TNF-α (SMD: -1.75, 95% CI -2.14 to -1.37), and MCP-1 (SMD: -2.04, 95% CI -2.91 to -1.17). The effect on CRP and TNF-α was of lesser magnitude in cases of empagliflozin use. Moderate-to-substantial heterogeneity and possible publication bias were noted. The findings remained largely unaffected after the sensitivity analyses, the exclusion of outlying studies, and trim-and-fill analyses.

CONCLUSION

The present meta-analysis suggests that SGLT2 inhibition results in reduction of inflammatory markers in animal models, further validating the suggested anti-inflammatory mechanism of action.

Lipidomic Analysis Reveals the Protection Mechanism of GLP-1 Analogue Dulaglutide on High-Fat Diet-Induced Chronic Kidney Disease in Mice

Many clinical studies have suggested that glucagon-like peptide-1 receptor agonists (GLP-1RAs) have renoprotective properties by ameliorating albuminuria and increasing glomerular filtration rate in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) by lowering ectopic lipid accumulation in the kidney. However, the mechanism of GLP-1RAs was hitherto unknown. Here, we conducted an unbiased lipidomic analysis using ultra-high-performance liquid chromatography/electrospray ionization-quadrupole time-of-flight mass spectrometry (UHPLC/ESI-Q-TOF-MS) and matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to reveal the changes of lipid composition and distribution in the kidneys of high-fat diet-fed mice after treatment with a long-acting GLP-1RA dulaglutide for 4 weeks. Treatment of dulaglutide dramatically improved hyperglycemia and albuminuria, but there was no substantial improvement in dyslipidemia and ectopic lipid accumulation in the kidney as compared with controls. Intriguingly, treatment of dulaglutide increases the level of an essential phospholipid constituent of inner mitochondrial membrane cardiolipin at the cortex region of the kidneys by inducing the expression of key cardiolipin biosynthesis enzymes. Previous studies demonstrated that lowered renal cardiolipin level impairs kidney function via mitochondrial damage. Our untargeted lipidomic analysis presents evidence for a new mechanism of how GLP-1RAs stimulate mitochondrial bioenergetics via increasing cardiolipin level and provides new insights into the therapeutic potential of GLP-1RAs in mitochondrial-related diseases.

Association of dipeptidyl peptidase-4 inhibitor use and the risk of asthma development among type 2 diabetes patients

Background:

Numerous studies have shown that dipeptidyl peptidase-4 inhibitors (DPP-4i) may regulate immunological pathways implicated in asthma. The association between DPP-4i use and risk of asthma development is limited, however.

Aim:

We aimed to evaluate if DPP-4i treatment in individuals with type 2 diabetes mellitus (T2DM) is associated with a lower risk and severity of asthma.

Methods:

We performed a population-based retrospective cohort study using the Longitudinal National Health Insurance Research database between 2008 and 2015. After one-to-four propensity score matching from 1,914,201 patients with defined criteria, we enrolled 3001 patients who were on DPP-4i (DPP-4i group) for a diagnosis of T2DM but without a diagnosis of asthma for further analysis. Cox proportional hazards regression analysis was performed to estimate and compare the risk of developing and severity of asthma, including no acute exacerbations event (No-AE), acute exacerbations (AEs), status asthmaticus (Status), and required endotracheal intubation (ET-tube intubated), between the two groups.

Results:

The participants had a mean age of 66.05 ± 17.23 years and the mean follow-up time was 4.96 ± 4.39 years. The risk of asthma development was significantly lower in the DPP-4i group than in the non-DPP-4i group [adjusted hazard ratio (HR) = 0.65; 95% confidence interval (CI) = 0.29–0.83; p < 0.001], with a class effect. This trend was observed for severity of asthma as No-AE (HR = 0.55; 95% CI = 0.24–0.70; p < 0.001), AE (HR = 0.57; 95% CI = 0.26–0.73; p < 0.001), and Status (HR = 0.78; 95% CI = 0.35–0.99; p = 0.047), but not in ET-tube intubated cases (HR = 0.96; 95% CI = 0.43–1.22; p = 0.258).

Conclusion:

The use of DPP-4i decreased the risk and severity of asthma with a class effect among No-AE, AE, status of asthma events, but not in ET-tube intubated events. Our report suggests that DPP-4i may play a role in attenuating the impact of asthma on incidence in the future and on more severe forms of disease exacerbation in T2DM patients.

Asthma Phenotype with Metabolic Dysfunction

Asthma is chronic eosinophilic bronchitis with the dominancy of T helper 2 (Th2) inflammation. However, patients with asthma and metabolic dysfunction have pathogenic and pathological differences from those with Th2 inflammation. Metabolic dysfunction, typically presented as metabolic syndrome, has several important clinical components including central obesity, insulin resistance or glucose intolerance, dyslipidemia, and vitamin D deficiency. Data from large epidemiological studies support the significance of these components in the control of asthma and their contribution to airway remodeling, suggesting the presence of an asthma phenotype with metabolic dysfunction. These components are quite interactive with each other, so it is difficult to reveal the individual role of each. It is well known that asthma is difficult to treat in patients with obesity, due in part to inadequate response to inhaled corticosteroids. Additionally, vitamin D deficiency and insulin resistance have been regarded as aggravating factors of asthma control and airway remodeling. Recent clinical and in vivo studies have revealed the specific mechanisms of these components, which may aggravate asthma control and airway remodeling. In this review article, I summarize the recent studies and unmet needs for patients with asthma and metabolic dysfunction.

Anisakis pegreffii Extract Induces Airway Inflammation with Airway Remodeling in a Murine Model System

Exposure of the respiratory system to the Anisakis pegreffii L3 crude extract (AE) induces airway inflammation; however, the mechanism underlying this inflammatory response remains unknown. AE contains allergens that promote allergic inflammation; exposure to AE may potentially lead to asthma. In this study, we aimed to establish a murine model to assess the effects of AE on characteristic features of chronic asthma, including airway hypersensitivity (AHR), airway inflammation, and airway remodeling. Mice were sensitized for five consecutive days each week for 4 weeks. AHR, lung inflammation, and airway remodeling were evaluated 24 h after the last exposure. Lung inflammation and airway remodeling were assessed from the bronchoalveolar lavage fluid (BALF). To confirm the immune response in the lungs, changes in gene expression in the lung tissue were assessed with reverse transcription-quantitative PCR. The levels of IgE, IgG1, and IgG2a in blood and cytokine levels in the BALF, splenocyte, and lung lymph node (LLN) culture supernatant were measured with ELISA. An increase in AHR was prominently observed in AE-exposed mice. Epithelial proliferation and infiltration of inflammatory cells were observed in the BALF and lung tissue sections. Collagen deposition was detected in lung tissues. AE exposure increased IL-4, IL-5, and IL-13 expression in the lung, as well as the levels of antibodies specific to AE. IL-4, IL-5, and IL-13 were upregulated only in LLN. These findings indicate that an increase in IL-4+ CD4+ T cells in the LLN and splenocyte resulted in increased Th2 response to AE exposure. Exposure of the respiratory system to AE resulted in an increased allergen-induced Th2 inflammatory response and AHR through accumulation of inflammatory and IL-4+ CD4+ T cells and collagen deposition. It was confirmed that A. pegreffii plays an essential role in causing asthma in mouse models and has the potential to cause similar effects in humans.

Therapeutic and diagnostic targeting of fibrosis in metabolic, proliferative and viral disorders

Fibrosis is a common denominator in many pathologies and crucially affects disease progression, drug delivery efficiency and therapy outcome. We here summarize therapeutic and diagnostic strategies for fibrosis targeting in atherosclerosis and cardiac disease, cancer, diabetes, liver diseases and viral infections. We address various anti-fibrotic targets, ranging from cells and genes to metabolites and proteins, primarily focusing on fibrosis-promoting features that are conserved among the different diseases. We discuss how anti-fibrotic therapies have progressed over the years, and how nanomedicine formulations can potentiate anti-fibrotic treatment efficacy. From a diagnostic point of view, we discuss how medical imaging can be employed to facilitate the diagnosis, staging and treatment monitoring of fibrotic disorders. Altogether, this comprehensive overview serves as a basis for developing individualized and improved treatment strategies for patients suffering from fibrosis-associated pathologies.

SGLT2 Inhibitors as Calorie Restriction Mimetics: Insights on Longevity Pathways and Age-Related Diseases

Sodium-glucose cotransporter-2 (SGLT2) inhibitors induce glycosuria, reduce insulin levels, and promote fatty acid oxidation and ketogenesis. By promoting a nutrient deprivation state, SGLT2 inhibitors upregulate the energy deprivation sensors AMPK and SIRT1, inhibit the nutrient sensors mTOR and insulin/IGF1, and modulate the closely linked hypoxia-inducible factor (HIF)-2α/HIF-1α pathways. Phosphorylation of AMPK and upregulation of adiponectin and PPAR-α favor a reversal of the metabolic syndrome which have been linked to suppression of chronic inflammation. Downregulation of insulin/IGF1 pathways and mTOR signaling from a reduction in glucose and circulating amino acids promote cellular repair mechanisms, including autophagy and proteostasis which confer cellular stress resistance and attenuate cellular senescence. SIRT1, another energy sensor activated by NAD+ in nutrient-deficient states, is reciprocally activated by AMPK, and can deacetylate and activate transcription factors, such as PCG-1α, mitochondrial transcription factor A (TFAM), and nuclear factor E2-related factor (NRF)-2, that regulate mitochondrial biogenesis. FOXO3 transcription factor which target genes in stress resistance, is also activated by AMPK and SIRT1. Modulation of these pathways by SGLT2 inhibitors have been shown to alleviate metabolic diseases, attenuate vascular inflammation and arterial stiffness, improve mitochondrial function and reduce oxidative stress-induced tissue damage. Compared with other calorie restriction mimetics such as metformin, rapamycin, resveratrol, and NAD+ precursors, SGLT2 inhibitors appear to be the most promising in the treatment of aging-related diseases, due to their regulation of multiple longevity pathways that closely resembles that achieved by calorie restriction and their established efficacy in reducing cardiovascular events and all-cause mortality. Evidence is compelling for the role of SGLT2 inhibitors as a calorie restriction mimetic in anti-aging therapeutics.

Association Between SGLT2is and Cardiovascular and Respiratory Diseases: A Meta-Analysis of Large Trials

The association between sodium-glucose cotransporter 2 inhibitors (SGLT2is) and various cardiovascular and respiratory diseases is unestablished. This meta-analysis aimed to explore whether use of SGLT2is is significantly associated with the occurrences of 80 types of cardiovascular diseases and 55 types of respiratory diseases. Large randomized trials of SGLT2is were included in analysis. Meta-analysis was conducted to synthesize risk ratio (RR) and 95% confidence interval (CI). Nine large trials were included in analysis. Compared to placebo, SGLT2is were associated with the reduced risks of 9 types of cardiovascular diseases (e.g., atrial fibrillation [RR 0.78, 95% CI 0.67-0.91], bradycardia [RR 0.60, 95% CI 0.40-0.89], and hypertensive emergency [RR 0.29, 95% CI 0.12-0.72]) and 11 types of respiratory diseases (e.g., chronic obstructive pulmonary disease [RR 0.77, 95% CI 0.61-0.97], asthma [RR 0.57, 95% CI 0.35-0.95], and sleep apnoea syndrome [RR 0.36, 95% CI 0.15-0.87]). The results of random-effects meta-analysis were similar with those of fixed-effects meta-analysis. No heterogeneity or only little heterogeneity was found in most meta-analyses. No publication bias was observed in most of the meta-analyses conducted in this study. SGLT2is were not significantly associated with the other 115 cardiovascular and respiratory diseases. SGLT2is are associated with the reduced risks of 9 types of cardiovascular diseases (e.g., atrial fibrillation, bradycardia, and hypertensive emergency) and 11 types of respiratory diseases (e.g., chronic obstructive pulmonary disease, asthma, and sleep apnoea syndrome). This proposes the potential of SGLT2is to be used for prevention of these cardiovascular and respiratory diseases.

Use of SGLT2 inhibitors and occurrence of noninfectious respiratory disorders: a meta-analysis of large randomized trials of SGLT2 inhibitors

PURPOSE

The impact of use of sodium-glucose transporter 2 (SGLT2) inhibitors on occurrence of various kinds of respiratory disorders has not been established. We aimed at evaluating the relationship between use of SGLT2 inhibitors and occurrence of 9 kinds of noninfectious respiratory disorders.

METHODS

Large randomized controlled trials (RCTs) of SGLT2 inhibitors were included in this study. We conducted fixed-effects meta-analysis to synthesize risk ratios (RRs) and 95% confidence intervals (CIs). We did subgroup analysis respectively stratified by type of underlying diseases and type of SGLT2 inhibitors.

RESULTS

Nine Large RCTs were included for analysis. Compared with placebo, SGLT2 inhibitors significantly reduced the occurrence of overall respiratory disorders (RR 0.75, 95% CI 0.62-0.91), acute pulmonary oedema (RR 0.51, 95% CI 0.29-0.88), asthma (RR 0.57, 95% CI 0.33-0.995), and sleep apnoea syndrome (RR 0.35, 95% CI 0.12-0.99). SGLT2 inhibitors showed the reduced trends in the risks of chronic obstructive pulmonary disease (COPD) (RR 0.79, 95% CI 0.61-1.02; P = 0.073) and pulmonary hypertension (RR 0.43, 95% CI 0.16-1.17; P = 0.098). SGLT2 inhibitors had no significant effects on three other respiratory disorders. These effects exhibited by SGLT2 inhibitors were consistent across different underlying diseases (P_subgroup ≥0.209) and different SGLT2 inhibitors (P_subgroup ≥0.192).

CONCLUSIONS

SGLT2 inhibitors can significantly reduce the occurrence of acute pulmonary oedema, asthma, and sleep apnoea syndrome; and produce the reduced trends in the risks of COPD and pulmonary hypertension. These findings will prompt further investigation on SGLT2 inhibitors for primary and secondary prevention of various respiratory disorders.

Use of GLP1RAs and occurrence of respiratory disorders: A meta-analysis of large randomized trials of GLP1RAs

OBJECTIVES

No large sample studies have been designed to evaluate the efficacy of glucagon-like peptide-1 receptor agonists (GLP1RAs) in the primary and secondary prevention of respiratory disorders. We aimed at evaluating the relationship between use of GLP1RAs and occurrence of 12 kinds of respiratory disorders.

METHODS

Large randomized placebo-controlled trials of GLP1RAs were included. We conducted meta-analysis using random effects model and measured heterogeneity using I² . Treatment effect was presented as risk ratio (RR) and 95% confidence interval (CI).

RESULTS

Seven trials including 55 922 participants were included in meta-analysis. The occurrence rates of various respiratory disorders were low, with the minimum of 0.02% (pulmonary fibrosis) and the maximum of 2.31% (pneumonia). Although not reaching statistical significance, GLP1RAs versus placebo showed the reduced trends in the risks of nine kinds of respiratory disorders including pneumonia (RR 0.89, 95% CI 0.78-1.01), squamous cell carcinoma of lung (SCCL; RR 0.55, 95% CI 0.25-1.21), asthma (RR 0.82, 95% CI 0.51-1.32), and chronic obstructive pulmonary disease (COPD; RR 0.89, 95% CI 0.73-1.10), but the increased trend in interstitial lung disease (ILD; RR 1.89, 95% CI 0.87-4.08). GLP1RAs had neutral effects on two other respiratory disorders. Heterogeneity in any meta-analysis was absent or low.

CONCLUSION

GLP1RAs show the reduced trends in the risks of nine kinds of respiratory disorders (eg, pneumonia, SCCL, asthma, and COPD), but the increased trend in the risk of ILD. However, these findings need to be validated by further studies due to the low incidence rates of all the respiratory disorders.

Empagliflozin therapy and insulin resistance-associated disorders: effects and promises beyond a diabetic state

Empagliflozin is a SGLT2 inhibitor that has shown remarkable cardiovascular and renal activities in patients with type 2 diabetes (T2D). Preclinical and clinical studies of empagliflozin in T2D population have demonstrated significant improvements in body weight, waist circumference, insulin sensitivity, and blood pressure – effects beyond its antihyperglycaemic control. Moreover, several studies suggested that this drug possesses significant anti-inflammatory and antioxidative stress properties. This paper explores extensively the main preclinical and clinical evidence of empagliflozin administration in insulin resistance-related disorders beyond a diabetic state. It also discusses its future perspectives, as a therapeutic approach, in this high cardiovascular-risk population.

Glucagon-like peptide 1 receptor (GLP-1R) agonist relieved asthmatic airway inflammation via suppression of NLRP3 inflammasome activation in obese asthma mice model

BACKGROUND

Obesity is a correctable factor for uncontrolled bronchial asthma. However, the effects of glucagon-like peptide-1 receptor (GLP-1R) agonist, a recently approved antiobestic drug, on airway hyperresponsiveness (AHR) and immune responses are not known.

METHODS

Mice were fed with high-fat diet (HFD, 60% fat) for 8 weeks to induce obesity. Ovalbumin (OVA) sensitization and challenges were performed for 7 weeks. The mice were injected intraperitoneally with GLP-1R agonist 5 times a week for 4 weeks after OVA sensitization. After AHR measurement, expression of Th2, Th17 cytokines, and interleukin (IL)-33 were measured in BALF and lung tissues. Moreover, IL-1β and activity level of nucleotide oligomerization domain-like receptor protein 3 (NLRP3) were analyzed to investigate the mechanism of GLP-1R agonist on asthmatic airway inflammation.

RESULTS

HFD induced significant weight gain, OVA sensitization and challenge in obese mice made eosinophilic airway inflammation, and increased AHR. Treatment with GLP-1R agonist-induced weight loss suppressed eosinophilic airway inflammation and decreased AHR. Expression of IL-4, 5, and 33 was increased in BALF of obese asthma mice followed by a decrease in response to GLP-1R agonist treatment. Moreover, lung tissue H&E stain revealed that peribronchial inflammation induced by obesity and OVA was effectively suppressed by GLP-1R agonist. Expressions of NLRP3, activated caspase-1, and IL-1β were increased in lung tissues of obese asthma mice and demonstrated a decrease in response to GLP-1R agonist treatment.

CONCLUSIONS

GLP-1R agonist effectively induced weight loss, suppressed eosinophilic bronchial airway inflammation, and AHR in obese asthma mice. These effects were mediated by suppression of NLRP3 inflammasome activity and IL-1β. GLP-1R agonist is proposed as a novel anti-asthmatic agent targeting the obese asthmatics.

Empagliflozin suppresses inflammation and protects against acute septic renal injury

BACKGROUND

Sepsis-induced systemic inflammation response syndrome is the leading cause of morbidity and mortality among patients in intensive care units in North America. While sepsis is associated with multiple organ damage, acute renal injury represents a hallmark of sepsis. Since systemic and renal inflammation is known to play a vital role in morbidity and mortality associated with sepsis, identifying a potent anti-inflammatory agent may help minimize morbidity and mortality associated with acute septic kidney injury. Since recent work has suggested that empagliflozin, a renal sodium-glucose cotransporter 2 (SGLT2) inhibitor, may assist in the treatment of inflammatory diseases, our objective was to examine the effect of empagliflozin on acute sepsis-induced renal injury.

METHOD

Mice were treated with three daily doses of empagliflozin or vehicle, with lipopolysaccharide (LPS) administered on the third day, at the same time as the third dose of empagliflozin or vehicle. In another cohort, mice were injected with a single dose of LPS 3 h before a dose of empagliflozin.

RESULTS

Our results show that empagliflozin improves survival in a mouse model of LPS-induced septic shock. We further demonstrate that the beneficial effects of empagliflozin are likely mediated via reducing LPS-induced acute renal injury. Moreover, our data indicate that empagliflozin significantly reduces systemic and renal inflammation to contribute to the improvements observed in an LPS-model of acute septic renal injury.

CONCLUSION

Overall, the findings of this study suggest that empagliflozin could be repurposed to reduce morbidity and mortality in patients with acute septic renal injury.

TRIAL REGISTRATION

Not applicable.