Pioglitazone stabilizes atherosclerotic plaque by regulating the Th17/Treg balance in AMPK-dependent mechanisms

Navigating the Maze of Kinases: CaMK-like Family Protein Kinases and Their Role in Atherosclerosis

Circulating low-density lipoprotein (LDL) levels are a major risk factor for cardiovascular diseases (CVD), and even though current treatment strategies focusing on lowering lipid levels are effective, CVD remains the primary cause of death worldwide. Atherosclerosis is the major cause of CVD and is a chronic inflammatory condition in which various cell types and protein kinases play a crucial role. However, the underlying mechanisms of atherosclerosis are not entirely understood yet. Notably, protein kinases are highly druggable targets and represent, therefore, a novel way to target atherosclerosis. In this review, the potential role of the calcium/calmodulin-dependent protein kinase-like (CaMKL) family and its role in atherosclerosis will be discussed. This family consists of 12 subfamilies, among which are the well-described and conserved liver kinase B1 (LKB1) and 5' adenosine monophosphate-activated protein kinase (AMPK) subfamilies. Interestingly, LKB1 plays a key role and is considered a master kinase within the CaMKL family. It has been shown that LKB1 signaling leads to atheroprotective effects, while, for example, members of the microtubule affinity-regulating kinase (MARK) subfamily have been described to aggravate atherosclerosis development. These observations highlight the importance of studying kinases and their signaling pathways in atherosclerosis, bringing us a step closer to unraveling the underlying mechanisms of atherosclerosis.

Decreased Treg cells induced by bisphenol A is associated with up-regulation of PI3K/Akt/mTOR signaling pathway and Foxp3 DNA methylation in spleen of adolescent mice

The current study aimed to explore whether bisphenol A (BPA) exposure aggravated the decrease in Tregs induced by ovalbumin (OVA) in adolescent female mouse models of asthma, and whether the process was associated with mTOR-mediated signaling pathways and DNA methylation levels. A total of 40 female C57BL/6 mice at the age of four weeks were used and divided into five groups after 1 week of domestication. Each group consisted of eight mice: the control group, OVA group, OVA + BPA (0.1 μg mL-1) group, OVA + BPA (0.2 μg mL-1) group, and OVA + BPA (0.4 μg mL-1) group. Results revealed that Foxp3 protein levels decreased in the spleens of mice exposed to BPA compared to those in the OVA group. After an elevation in BPA dose, the mRNAs of methyltransferases (Dnmt1, Dnmt3a, and Dnmt3b) were gradually upregulated. The mechanism was related to the activity of TLR4/NF-κB and PI3K/Akt/mTOR signaling pathways and the enhancement of Foxp3 DNA methylation. Our results, collectively, provided a new view for studying the mechanisms underlying BPA exposure-induced immune dysfunction. Investigation of the regulatory mechanisms of DNA methylation in the abnormal Th immune response caused by BPA exposure could help reveal the causes and molecular mechanisms underlying the high incidence of allergic diseases in children in recent years.

Two sides of the same coin: Non-alcoholic fatty liver disease and atherosclerosis

The prevalence of non-alcoholic fatty liver disease (NAFLD) and atherosclerosis remain high, which is primarily due to widespread adoption of a western diet and sedentary lifestyle. NAFLD, together with advanced forms of this disease such as non-alcoholic steatohepatitis (NASH) and cirrhosis, are closely associated with atherosclerotic-cardiovascular disease (ASCVD). In this review, we discussed the association between NAFLD and atherosclerosis and expounded on the common molecular biomarkers underpinning the pathogenesis of both NAFLD and atherosclerosis. Furthermore, we have summarized the mode of function and potential clinical utility of existing drugs in the context of these diseases.

Primordial Drivers of Diabetes Heart Disease: Comprehensive Insights into Insulin Resistance

Insulin resistance has been regarded as a hallmark of diabetes heart disease (DHD). Numerous studies have shown that insulin resistance can affect blood circulation and myocardium, which indirectly cause cardiac hypertrophy and ventricular remodeling, participating in the pathogenesis of DHD. Meanwhile, hyperinsulinemia, hyperglycemia, and hyperlipidemia associated with insulin resistance can directly impair the metabolism and function of the heart. Targeting insulin resistance is a potential therapeutic strategy for the prevention of DHD. Currently, the role of insulin resistance in the pathogenic development of DHD is still under active research, as the pathological roles involved are complex and not yet fully understood, and the related therapeutic approaches are not well developed. In this review, we describe insulin resistance and add recent advances in the major pathological and physiological changes and underlying mechanisms by which insulin resistance leads to myocardial remodeling and dysfunction in the diabetic heart, including exosomal dysfunction, ferroptosis, and epigenetic factors. In addition, we discuss potential therapeutic approaches to improve insulin resistance and accelerate the development of cardiovascular protection drugs.

Pi-Pa-Run-Fei-Tang alleviates lung injury by modulating IL-6/JAK2/STAT3/IL-17 and PI3K/AKT/NF-κB signaling pathway and balancing Th17 and Treg in murine model of OVA-induced asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Pi-Pa-Run-Fei-Tang (PPRFT) is an empirical TCM prescription for treating asthma. However, the underlying mechanisms of PPRFT in asthma treatment have yet to be elucidated. Recent advances have revealed that some natural components could ameliorate asthma injury by affecting host metabolism. Untargeted metabolomics can be used to better understand the biological mechanisms underlying asthma development and identify early biomarkers that can help advance treatment.

AIM OF THE STUDY

The aim of this study was to verification the efficacy of PPRFT in the treatment of asthma and to preliminarily explore its mechanism.

MATERIALS AND METHODS

A mouse asthma model was built by OVA induction. Inflammatory cell in BALF was counted. The level of IL-6, IL-1β, and TNF-α in BALF were measured. The levels of IgE in the serum and EPO, NO, SOD, GSH-Px, and MDA in the lung tissue were measured. Furthermore, pathological damage to the lung tissues was detected to evaluate the protective effects of PPRFT. The serum metabolomic profiles of PPRFT in asthmatic mice were determined by GC-MS. The regulatory effects on mechanism pathways of PPRFT in asthmatic mice were explored via immunohistochemical staining and western blotting analysis.

RESULTS

PPRFT displayed lung-protective effects through decreasing oxidative stress, airway inflammation, and lung tissue damage in OVA-induced mice, which was demonstrated by decreasing inflammatory cell levels, IL-6, IL-1β, and TNF-α levels in BALF, and IgE levels in serum, decreasing EPO, NO, and MDA levels in lung tissue, elevating SOD and GSH-Px levels in lung tissue and lung histopathological changes. In addition, PPRFT could regulate the imbalance in Th17/Treg cell ratios, suppress RORγt, and increase the expression of IL-10 and Foxp3 in the lung. Moreover, PPRFT treatment led to decreased expression of IL-6, p-JAK2/Jak2, p-STAT3/STAT3, IL-17, NF-κB, p-AKT/AKT, and p-PI3K/PI3K. Serum metabolomics analysis revealed that 35 metabolites were significantly different among different groups. Pathway enrichment analysis indicated that 31 pathways were involved. Moreover, correlation analysis and metabolic pathway analysis identified three key metabolic pathways: galactose metabolism; tricarboxylic acid cycle; and glycine, serine, and threonine metabolism.

CONCLUSION

This research indicated that PPRFT treatment not only attenuates the clinical symptoms of asthma but is also involved in regulating serum metabolism. The anti-asthmatic activity of PPRFT may be associated with the regulatory effects of IL-6/JAK2/STAT3/IL-17 and PI3K/AKT/NF-κB mechanistic pathways.

Circulating Th17/Treg as a promising biomarker for patients with rheumatoid arthritis in indicating comorbidity with atherosclerotic cardiovascular disease

BACKGROUND

Immune and inflammatory responses have a pivotal role in the pathogenesis of rheumatoid arthritis (RA) and atherosclerotic cardiovascular disease (ASCVD). This study aims to explore the change of peripheral lymphocytes, especially the absolute and relative changes in peripheral T cells in RA patients with and without ASCVD.

HYPOTHESIS

The changes in the lymphocyte subsets were assessed to provide a novel insight in diagnosing and preventing ASCVD in patients with RA.

METHODS

A propensity score matching system (1:1) was conducted to perform a matched case-control study with 169 pairs RA-ASCVD and RA participants. Univariate and multivariate analyses were performed to determine the association between peripheral lymphocytes and RA-ASCVD.

RESULT

Multivariate logistic regression analysis demonstrated that Th17 cell absolute, Th17 cell Ratio, Th17/Treg were associated with a significantly higher risk of ASCVD after model adjustment. Then we focused on Th17/Treg, multivariate logistic analyses in tri-sectional Th17/Treg groups showed that the odds of ASCVD is gradually increasing with Th17/Treg rank's rising after model adjustment. Finally, the restricted cubic spline of Th17/Treg and odds ratio of RA-ASCVD was conducted. Interestingly, we found a critical point of Th17/Treg (critical point = 0.2399). Th17/Treg shows a protective role in the odds of ASCVD when Th17/Treg < 0.2399. With smaller Th17/Treg, the protective efficiency is more obvious when Th17/Treg < 0.2399.

CONCLUSIONS

Our study suggested that increasing absolute and percentage of Th17 cells in the peripheral blood of patients with RA was associated with the development of ASCVD. And Th17/Treg may be a promising biomarker for patients with RA in indicating comorbidity with ASCVD.

Chloroquine Alleviates Atherosclerosis by Modulating Regulatory T Cells Through the ATM/AMPK/mTOR Signaling Pathway in ApoE -/- Mice

BACKGROUND

Clinical observation suggests the atheroprotective effect of chloroquine and its derivatives, while its mechanism remains unclear. This study aimed to observe the protective effect of chloroquine against atherosclerosis and explore the underlying mechanism.

METHODS

Ataxia telangiectasia mutated (ATM) wild-type or haploinsufficient apolipoprotein-E-knockout (ATM+/+ApoE-/- or ATM+/-ApoE-/-) mice were treated with different dosages of chloroquine. Anti-CD25 antibody was used to deplete natural Tregs in ATM+/+ApoE-/- mice. The atherosclerotic burden in different groups of mice was comprehensively evaluated by H&E staining and Masson staining. The effect of chloroquine on the regulatory T cells (Tregs) was assessed in vivo and in vitro by flow cytometry and immunohistochemical staining. The expression of related proteins was detected by real-time polymerase chain reaction and western blotting.

RESULTS

In ATM+/+ApoE-/- mice, chloroquine alleviated atherosclerotic lesions, stabilized the plaque, and increased Treg counts in the atherosclerotic lesions and spleens. However, in ATM haploinsufficient mice (ATM+/-ApoE-/-), chloroquine no longer prevented atherosclerosis or impacted Treg counts. Abolishing Treg cells using an anti-CD25 antibody in vivo abrogated the atheroprotective effect of chloroquine. In vitro, chloroquine promoted the differentiation of Tregs from naïve T cells, which was accompanied by enhanced ATM/AMP-activated protein kinase (AMPK) activity and reduced downstream mammalian target of rapamycin (mTOR) activity.

DISCUSSION

These findings suggest that chloroquine ameliorates atherosclerosis and stabilizes plaque by modulating Tregs differentiation through the regulation of the ATM/AMPK/mTOR pathway.

Influence of Age, Gender, Frailty, and Body Mass Index on Serum IL-17A Levels in Mature Type 2 Diabetic Patients

BACKGROUND The cytokine IL-17A is emerging as a marker of chronic inflammation in cardio-metabolic conditions. This study aimed to identify relevant factors that in older primary care patients with type 2 diabetes (T2D) could influence serum IL-17A concentrations. The results have a potential to improve risk stratification and therapy options for these patients. MATERIAL AND METHODS The study was conducted during a period of 4 months, in 2020, in the south-eastern region of Croatia. Patients from primary health care, diagnosed with T2D (N=170, M: F 75: 95, ≥50 years old), were recruited at their visits. Those with malignant diseases, on chemotherapy or biological therapy, with amputated legs, or at hemodialysis, were excluded. The multinomial regression models were used to determine independent associations of the groups of variables, indicating sociodemographic and clinical characteristics of these patients, with increasing values (quartiles) of serum IL-17A. RESULTS The regression models indicated the frailty index and sex bias are the key modifying factors in associations of other variables with IL-17A serum values. CONCLUSIONS Sex bias and the existence of different frailty phenotypes could be the essential determining factors of the serum IL-17A levels in community-dwelling patients with T2D age 50 years and older. The results support the concept of T2D as a complex disorder.

Targeting the metabolism of tumor-infiltrating regulatory T cells

Although targeting the tumor metabolism is performed in cooperation with immunotherapy in the era of precision oncology, ignorance of immune cells' metabolism has resulted in unstable antitumor responses. Tumor-infiltrating regulatory T cells (TI-Tregs) are unique, overcoming the hypoxic, acidic, and nutrient-deficient tumor microenvironments (TMEs) and maintaining immunosuppressive functions. However, secondary autoimmunity caused by systemic Treg depletion remains the 'Sword of Damocles' for current Treg-targeted therapies. In this opinion piece, we propose that metabolically reprogrammed TI-Tregs might represent an obstacle to cancer therapies. Indeed, metabolism-based Treg-targeted therapy might provide higher selectivity for clearing TI-Tregs than traditional kinase/checkpoint inhibitors and chemokine/chemokine receptor blockade; it might also restore the efficacy of targeting the tumor metabolism and eliminate certain metabolic barriers to immunotherapy.

PROTECTIVE EFFECTS OF HUMANIN-G IN HEMORRHAGIC SHOCK IN FEMALE MICE VIA AMPKα1-INDEPENDENT MECHANISMS

ABSTRACT

Introduction: Despite therapeutic advances in hemorrhagic shock, mortality from multiple organ failure remains high. We previously showed that the α1 subunit of AMP-activated protein kinase (AMPK), a crucial regulator of mitochondrial function, exerts a protective role in hemorrhagic shock. Humanin is a mitochondrial peptide with cytoprotective properties against cellular stress. Here, we investigated whether AMPKα1 influences systemic levels of endogenous humanin in hemorrhagic shock and whether treatment with the synthetic analog humanin-G affords beneficial effects. Methods: AMPKα1 wild-type (WT) and knockout (KO) female mice were subjected to hemorrhagic shock followed by resuscitation with blood and lactated Ringer's solution. In short-term studies, mice were treated with humanin-G or vehicle and sacrificed at 3 h after resuscitation; in survival studies, mice were treated with PEGylated humanin-G and monitored for 7 days. Results: Compared with the vehicle WT group, KO mice exhibited severe hypotension, cardiac mitochondrial damage, and higher plasma levels of Th17 cytokines but had similar lung injury and similar plasma elevation of endogenous humanin. Treatment with humanin-G improved lung injury, mean arterial blood pressure, and survival in both WT and KO mice, without affecting systemic cytokine or humanin levels. Humanin-G also ameliorated cardiac mitochondrial damage and increased adenosine triphosphate levels in KO mice. Beneficial effects of humanin-G were associated with lung cytoplasmic and nuclear activation of the signal transducer and activator of transcription-3 (STAT3) in AMPKα1-independent manner with marginal or no effects on mitochondrial STAT3 and complex I subunit GRIM-19. Conclusions: Our data indicate that circulating levels of humanin increase during hemorrhagic shock in AMPKα1-independent fashion as a defense mechanism to counteract metabolic derangement and that administration of humanin-G affords beneficial effects through STAT3 activation even in the absence of a functional AMPKα1.

Targeting regulatory T cells for cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death and disability worldwide. The CVDs are accompanied by inflammatory progression, resulting in innate and adaptive immune responses. Regulatory T cells (Tregs) have an immunosuppressive function and are one of the subsets of CD4⁺T cells that play a crucial role in inflammatory diseases. Whether using Tregs as a biomarker for CVDs or targeting Tregs to exert cardioprotective functions by regulating immune balance, suppressing inflammation, suppressing cardiac and vascular remodeling, mediating immune tolerance, and promoting cardiac regeneration in the treatment of CVDs has become an emerging research focus. However, Tregs have plasticity, and this plastic Tregs lose immunosuppressive function and produce toxic effects on target organs in some diseases. This review aims to provide an overview of Tregs' role and related mechanisms in CVDs, and reports on the research of plasticity Tregs in CVDs, to lay a foundation for further studies targeting Tregs in the prevention and treatment of CVDs.

5'AMP-activated protein kinase: an emerging target of phytochemicals to treat chronic inflammatory diseases

Inflammation is a defensive response of the organism to traumatic, infectious, toxic, ischemic, and autoimmune injury. Inflammatory mediators are released to effectively eliminate the inflammatory trigger and restore homeostasis. However, failure of these processes can lead to chronic inflammatory conditions and diseases such as inflammatory bowel diseases, rheumatoid arthritis, inflammatory lung diseases, atherosclerosis, and neurodegenerative diseases. The cure of chronic inflammatory diseases remains challenging as current therapies have various limitations, such as pronounced side effects, progressive loss of efficacy, and high cost especially for biologics. In this context, phytochemicals (such as alkaloids, flavonoids, lignans, phenolic acids, saponins, terpenoids, and other classes) are considered as an interesting alternative approach. Among the numerous targets of phytochemicals, AMP-activated protein kinase (AMPK) can be considered as an interesting target in the context of inflammation. AMPK regulates inflammatory response by inhibiting inflammatory pathways (NF-κB, JAK/STAT, and MAPK) and regulating several other processes of the inflammatory response (oxidative stress, autophagy, and apoptosis). In this review, we summarize and discuss the studies focusing on phytochemicals that showed beneficial effects by blocking different inflammatory pathways implicating AMPK activation in chronic inflammatory disease models. We also highlight elements to consider when investigating AMPK in the context of phytochemicals.

Research progress on Th17 and T regulatory cells and their cytokines in regulating atherosclerosis

Background

Coronary heart disease due to atherosclerosis is the leading cause of death worldwide. Atherosclerosis is considered a chronic inflammatory state in the arterial wall that promotes disease progression and outcome, and immune cells play an important role in the inflammatory process.

Purpose

We review the mechanisms of CD4+ T subsets, i.e., helper T17 (Th17) cells and regulatory T cells (Tregs), in regulating atherosclerosis, focusing on the role of interleukin (IL)-17, IL-10, and other cytokines in this disease and the factors influencing the effects of these cytokines.

Results

IL-17 secreted by Th17 cells can promote atherosclerosis, but few studies have reported that IL-17 can also stabilize atherosclerotic plaques. Tregs play a protective role in atherosclerosis, and Th17/Treg imbalance also plays an important role in atherosclerosis.

Conclusion

The immune response is important in regulating atherosclerosis, and studying the mechanism of action of each immune cell on atherosclerosis presents directions for the treatment of atherosclerosis. Nevertheless, the current studies are insufficient for elucidating the mechanism of action, and further in-depth studies are needed to provide a theoretical basis for clinical drug development.

The Anti-Atherosclerosis Effect of Anakinra, a Recombinant Human Interleukin-1 Receptor Antagonist, in Apolipoprotein E Knockout Mice

Interleukin (IL)-1β plays an important role in atherosclerosis pathogenesis. We aimed to investigate the effect of anakinra, a recombinant human IL-1 receptor antagonist, on the progression of atherosclerosis in apolipoprotein E knockout (ApoE−/−) mice. ApoE−/− mice (8-week male) were treated with saline (control), anakinra 10, 25, and 50 mg/kg, respectively (n = 10 in each group). Mice were fed a standard chow (4 weeks) followed by an atherogenic diet (35kcal% fat, 1.25% cholesterol, 12 weeks). Atheromatous plaques in ApoE−/− mice and the expression of inflammatory genes and signaling pathways in human umbilical vein endothelial cells (HUVECs), rat aortic smooth muscle cells (RAOSMCs), and 3T3-L1 adipocytes were assessed. Anakinra reduced the plaque size of the aortic arch (30.6% and 25.2% at the 25 mg/kg and 50 mg/kg doses, both p < 0.05) and serum triglyceride in ApoE−/− mice and suppressed inflammatory genes (IL-1β and IL-6) expressions in HUVECs and RAOSMCs (all p < 0.05). In RAOSMCs, anakinra reduced metalloproteinase-9 expression in a dose-dependent manner and inhibited cell migration. Anakinra-treated mice exhibited trends of lower CD68+ macrophage infiltration in visceral fat and monocyte chemoattractant protein-1 expression was reduced in 3T3-L1 adipocytes. Anakinra could be a useful component for complementary treatment with a standard regimen to reduce the residual cardiovascular risk.

P2Y1R Ligation Suppresses Th17 Cell Differentiation and Alleviates Colonic Inflammation in an AMPK-Dependent Manner

P2Y1 receptor is a G-protein-coupled receptor that plays a critical role in the immune response of inflammatory bowel diseases. However, its regulatory effects on CD4⁺ T cell response have not been fully elucidated. The study aimed to characterize the role of P2Y1R in Th17 cell differentiation and colonic inflammation. Our results demonstrated that P2Y1R was significantly increased in the splenocytes of colitic mice, which was positively associated with the expression of RORγt and IL-17A. P2Y1R deficiency significantly ameliorated DSS-induced colitis and its Th17 responses. In parallel, P2Y1R deficiency greatly impaired the differentiation of Th17 cell, down-regulated the mRNA expression of IL-17A and RORγt, and protein expression of RORγt in vitro. More importantly, it was found that P2Y1R deficiency markedly increased AMPK phosphorylation of Th17 polarized CD4⁺ T cells, and antagonist of AMPK significantly reversed the inhibitory effect of P2Y1R deficiency on Th17 cell generation in vivo and in vitro. Overall, these findings demonstrated that P2Y1R deficiency could suppress Th17 cell differentiation in an AMPK-dependent manner to ameliorate colitis, and P2Y1R can act as an important regulator of Th17 cell differentiation to control colonic inflammation.

Bergenin, a PPARγ agonist, inhibits Th17 differentiation and subsequent neutrophilic asthma by preventing GLS1-dependent glutaminolysis

Bergenin is a natural PPARγ agonist that can prevent neutrophil aggregation, and often be used in clinics for treating respiratory diseases. Recent data show that Th17 cells are important for neutrophil aggregation and asthma through secreting IL-17A. In this study, we investigated the effects of bergenin on Th17 differentiation in vitro and subsequent neutrophilic asthma in mice. Naïve T cells isolated from mouse mesenteric lymph nodes were treated with IL-23, TGF-β, and IL-6 to induce Th17 differentiation. We showed that in naïve T cells under Th17-polarizing condition, the addition of bergenin (3, 10, 30 μM) concentration-dependently decreased the percentage of CD4⁺ IL-17A⁺ T cells and mRNA expression of specific transcription factor RORγt, and function-related factors IL-17A/F, IL-21, and IL-22, but did not affect the cell vitality and apoptosis. Furthermore, bergenin treatment prevented GLS1-dependent glutaminolysis in the progress of Th17 differentiation, slightly affected the levels of SLC1A5, SLC38A1, GLUD1, GOT1, and GPT2. Glutamine deprivation, the addition of glutamate (1 mM), α-ketoglutarate (1 mM), or GLS1 plasmid all significantly attenuated the above-mentioned actions of bergenin. Besides, we demonstrated that bergenin (3, 10, and 30 μM) concentration-dependently activated PPARγ in naïve T cells, whereas PPARγ antagonist GW9662 and siPPARγ abolished bergenin-caused inhibition on glutaminolysis and Th17 differentiation. Furthermore, we revealed that bergenin inhibited glutaminolysis by regulating the level of CDK1, phosphorylation and degradation of Cdh1, and APC/C-Cdh1-mediated ubiquitin-proteasomal degradation of GLS1 after activating PPARγ. We demonstrated a correlation existing among bergenin-affected GLS1-dependent glutaminolysis, PPARγ, "CDK1-APC/C-Cdh1" signaling, and Th17 differentiation. Finally, the therapeutic effect and mechanisms for bergenin-inhibited Th17 responses and neutrophilic asthma were confirmed in a mouse model of neutrophilic asthma by administration of GW9662 or GLS1 overexpression plasmid in vivo. In conclusion, bergenin repressed Th17 differentiation and then alleviated neutrophilic asthma in mice by inhibiting GLS1-dependent glutaminolysis via regulating the "CDK1-APC/C-Cdh1" signaling after activating PPARγ.

AMP-activated protein kinase alpha1 promotes tumor development via FOXP3 elevation in tumor-infiltrating Treg cells

Overwhelming evidence indicates that infiltration of tumors by Treg cells with elevated levels of FOXP3 suppresses the host antitumor immune response. However, the molecular mechanisms that maintain high expression of FOXP3 in tumor-infiltrating Treg cells remain elusive. Here, we report that AMP-activated protein kinase alpha1 (AMPKα1) enables high FOXP3 expression in tumor-infiltrating Treg cells. Mice with Treg-specific AMPKα1 deletion showed delayed tumor progression and enhanced antitumor T cell immunity. Further experiments showed that AMPKα1 maintains the functional integrity of Treg cells and prevents interferon-γ production in tumor-infiltrating Treg cells. Mechanistically, AMPKα1 maintains the protein stability of FOXP3 in Treg cells by downregulating the expression of E3 ligase CHIP (STUB1). Our results suggest that AMPKα1 activation promotes tumor growth by maintaining FOXP3 stability in tumor-infiltrating Treg cells and that selective inhibition of AMPK in Treg cells might be an effective anti-tumor therapy.

Therapeutic Effect of Schistosoma japonicum Cystatin on Atherosclerotic Renal Damage

Atherosclerosis is a chronic inflammation of the arterial vessel wall driven by lipid metabolism disorders. Although helminthic infection and their derivatives have been identified to attenuate the chronic inflammatory diseases, the immunomodulatory effect of recombinant Schistosoma japonicum cystatin (rSj-Cys) on metabolic diseases and atherosclerosis has not been reported. In this study, we investigated the therapeutic efficacy of rSj-Cys on atherosclerotic renal damage and explored the related immunological mechanism. The results demonstrated that treatment with rSj-Cys significantly reduced body weight gain, hyperlipidemia, and atherosclerosis induced by the high-fat diet in apoE^–/– mice. The treatment of rSj-Cys also significantly improved kidney functions through promoting macrophage polarization from M1 to M2, therefore inhibiting M1 macrophage–induced inflammation. The possible mechanism underlying the regulatory effect of rSj-Cys on reducing atherosclerosis and atherosclerotic renal damage is that rSj-Cys stimulates regulatory T cell and M2 macrophage polarization that produce regulatory cytokines, such as interleukin 10 and transforming growth factor β. The therapeutic effect of rSj-Cys on atherosclerotic renal damage is possibly through inhibiting the activation of TLR2/Myd88 signaling pathway. The results in this study provide evidence for the first time that Schistosoma-derived cystatin could be developed as a therapeutic agent to treat lipid metabolism disorder and atherosclerosis that threats million lives around the world.

Mechanistic Insight into PPARγ and Tregs in Atherosclerotic Immune Inflammation

Atherosclerosis (AS) is the main pathological cause of acute cardiovascular and cerebrovascular diseases, such as acute myocardial infarction and cerebral apoplexy. As an immune-mediated inflammatory disease, the pathogenesis of AS involves endothelial cell dysfunction, lipid accumulation, foam cell formation, vascular smooth muscle cell (VSMC) migration, and inflammatory factor infiltration. The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) plays an important role in lipid metabolism, inflammation, and apoptosis by antagonizing the Wnt/β-catenin pathway and regulating cholesterol efflux and inflammatory factors. Importantly, PPARγ-dependant fatty acid uptake is critical for metabolic programming. Activated PPARγ can exert an anti-atherosclerotic effect by inhibiting the expression of various inflammatory factors, improving endothelial cell function, and restraining the proliferation and migration of VSMCs. Regulatory T cells (Tregs) are the only subset of T lymphocytes that have a completely negative regulatory effect on the autoimmune response. They play a critical role in suppressing excessive immune responses and inflammatory reactions and widely affect AS-associated foam cell formation, plaque rupture, and other processes. Recent studies have shown that PPARγ activation promotes the recruitment of Tregs to reduce inflammation, thereby exerting its anti-atherosclerotic effect. In this review, we provide an overview of the anti-AS roles of PPARγ and Tregs by discussing their pathological mechanisms from the perspective of AS and immune-mediated inflammation, with a focus on basic research and clinical trials of their efficacies alone or in combination in inhibiting atherosclerotic inflammation. Additionally, we explore new ideas for AS treatment and plaque stabilization and establish a foundation for the development of natural PPARγ agonists with Treg recruitment capability.

Transcriptional and posttranslational regulation of Th17/Treg balance in health and disease

Regulatory T (Treg) cells and T helper type 17 (Th17) cells play important roles in adaptive immune responses, antagonizing each other in immune disorders. Th17/Treg balance is critical to maintaining the immune homeostasis of human bodies and is tightly regulated under healthy conditions. The transcription factors that are required for driving Th17 and Treg cell lineages differentiation respectively, RORγt and FOXP3 are tightly regulated under different tissue microenvironment, especially the transcriptional induction, posttranslational modifications, and dynamic enzymatic cofactors binding. The imbalance caused by alteration of the quantity or properties of RORγt⁺ Th17 or FOXP3⁺ Treg can contribute to inflammatory disorders in humans. Restoring Th17/Treg balance by modifying the enzymatic activities of RORγt and FOXP3 binding partners may be therapeutically applied to treat severe immune disorders. In this review, we focus on the transcriptional and posttranslational regulations of Th17/Treg balance, immune disorders caused by Th17/Treg imbalance, and new therapeutic strategies for restoring immune homeostasis.

Antidiabetic drugs and oxidized low-density lipoprotein: A review of anti-atherosclerotic mechanisms

Cardiovascular disease is one of the leading causes of mortality globally. Atherosclerosis is an important step towards different types of cardiovascular disease. The role of oxidized low-density lipoprotein (oxLDL) in the initiation and progression of atherosclerosis has been thoroughly investigated in recent years. Moreover, clinical trials have established that diabetic patients are at a greater risk of developing atherosclerotic plaques. Hence, we aimed to review the clinical and experimental impacts of various classes of antidiabetic drugs on the circulating levels of oxLDL. Metformin, pioglitazone, and dipeptidyl peptidase-4 inhibitors were clinically associated with a suppressive effect on oxLDL in patients with impaired glucose tolerance. However, there is an insufficient number of studies that have clinically evaluated the relationship between oxLDL and newer agents such as agonists of glucagon-like peptide 1 receptor or inhibitors of sodium-glucose transport protein 2. Next, we attempted to explore the multitude of mechanisms that antidiabetic agents exert to counter the undesirable effects of oxLDL in macrophages, endothelial cells, and vascular smooth muscle cells. In general, antidiabetic drugs decrease the uptake of oxLDL by vascular cells and reduce subsequent inflammatory signaling, which prevents macrophage adhesion and infiltration. Moreover, these agents suppress the oxLDL-induced transformation of macrophages into foam cells by either inhibiting oxLDL entrance, or by facilitating its efflux. Thus, the anti-inflammatory, anti-oxidant, and anti-apoptotic properties of antidiabetic agents abrogate changes induced by oxLDL, which can be extremely beneficial in controlling atherosclerosis in diabetic patients.

Traffic-related PM2.5 and diverse constituents disturb the balance of Th17/Treg cells by STAT3/RORγt-STAT5/Foxp3 signaling pathway in a rat model of asthma

Water-soluble ions (WSI) and organic extract (OE) in traffic-related particulate matter with aerodynamic diameters ≤ 2.5 μm (TRPM2.5) are potential risk factors for asthma exacerbation. Although CD4+ T lymphocytes mediated immune response is involved in the pathogenesis of asthma, the effect of WSI-TRPM2.5 and OE-TRPM2.5 on the balance of Th17/Treg cells in asthma remains poorly understood. In this study, the ovalbumin (OVA)-sensitized rats were repeatedly exposure to TRPM2.5 (3 mg/kg·bw), WSI-TRPM2.5 (1.8 mg/kg·bw, 7.2 mg/kg·bw) and OE-TRPM2.5 (0.6 mg/kg·bw, 2.4 mg/kg·bw) every three days for five times. The inflammation response and hyperemia edema were observed in the lung and trachea tissues. DNA methylation levels of STAT3 and RORγt genes in rats with WSI-TRPM2.5 and OE-TRPM2.5 treatment were decreased. DNA methylation level in STAT5 gene tended to decrease, with no change observed on Foxp3 expression. WSI-TRPM2.5 and OE-TRPM2.5 enhanced the mRNA and protein expression of STAT3 and RORγt while inhibited the expression of STAT5 and Foxp3, which may contribute to the imbalance of Th17/Treg cells (P < 0.05). More importantly, recovered balance of Th17/Treg cell subsets, upregulated p-STAT5 and Foxp3 expression and reduced p-STAT3 and RORγt levels were observed after 5-Aza treatment. Our results demonstrate that the STAT3/RORγt-STAT5/Foxp3 signaling pathway is involved in asthma exacerbation induced by WSI-TRPM2.5 and OE-TRPM2.5 through disrupting the balance of Th17/Treg cells. The alteration of DNA methylation of STAT3, STAT5, and RORγt genes may be involved in asthma exacerbation as well.

Treg cells in atherosclerosis

Atherosclerosis involves both innate and adaptive immunity. Here, we provide an overview of the role of regulatory T (Treg) cells in atherosclerotic diseases. Treg cells and their inhibitory cytokines, IL-10 and TGF-β, have been identified in atherosclerotic lesions and to inhibit progression through lipoprotein metabolism modulation. Treg cells have also been found to convert to T follicular helper (Tfh) cells and promote atherosclerosis progression. Treg cell involvement in different stages of atherosclerotic progression and Treg cell-mediated modulation of plaque development occurs via inflammation suppression and atheroma formation has been focused. Moreover, existing knowledge suggests that Treg cells are likely involved in the pathology of other specific circumstances including in-stent restenosis, neointimal hyperplasia, vessel graft failure, and ischemic arterial injury; however, there remain gaps regarding their specific contribution. Hence, advancements in the knowledge regarding Treg cells in diverse aspects of atherosclerosis offer translational significance for the management of atherosclerosis and associated diseases.

Different Approaches in Therapy Aiming to Stabilize an Unstable Atherosclerotic Plaque

Atherosclerotic plaque vulnerability is a vital clinical problem as vulnerable plaques tend to rupture, which results in atherosclerosis complications—myocardial infarctions and subsequent cardiovascular deaths. Therefore, methods aiming to stabilize such plaques are in great demand. In this brief review, the idea of atherosclerotic plaque stabilization and five main approaches—towards the regulation of metabolism, macrophages and cellular death, inflammation, reactive oxygen species, and extracellular matrix remodeling have been presented. Moreover, apart from classical approaches (targeted at the general mechanisms of plaque destabilization), there are also alternative approaches targeted either at certain plaques which have just become vulnerable or targeted at the minimization of the consequences of atherosclerotic plaque erosion or rupture. These alternative approaches have also been briefly mentioned in this review.

From Mitochondria to Atherosclerosis: The Inflammation Path

Inflammation is a key process in metazoan organisms due to its relevance for innate defense against infections and tissue damage. However, inflammation is also implicated in pathological processes such as atherosclerosis. Atherosclerosis is a chronic inflammatory disease of the arterial wall where unstable atherosclerotic plaque rupture causing platelet aggregation and thrombosis may compromise the arterial lumen, leading to acute or chronic ischemic syndromes. In this review, we will focus on the role of mitochondria in atherosclerosis while keeping inflammation as a link. Mitochondria are the main source of cellular energy. Under stress, mitochondria are also capable of controlling inflammation through the production of reactive oxygen species (ROS) and the release of mitochondrial components, such as mitochondrial DNA (mtDNA), into the cytoplasm or into the extracellular matrix, where they act as danger signals when recognized by innate immune receptors. Primary or secondary mitochondrial dysfunctions are associated with the initiation and progression of atherosclerosis by elevating the production of ROS, altering mitochondrial dynamics and energy supply, as well as promoting inflammation. Knowing and understanding the pathways behind mitochondrial-based inflammation in atheroma progression is essential to discovering alternative or complementary treatments.

Cardiovascular Safety and Benefits of Noninsulin Antihyperglycemic Drugs for the Treatment of Type 2 Diabetes Mellitus-Part 1

Cardiovascular disease (CVD) is a major contributor to the morbidity and mortality associated with type 2 diabetes mellitus (T2DM). With T2DM growing in pandemic proportions, there will be profound healthcare implications of CVD in person with diabetes. The ideal drugs to improve outcomes in T2DM are those having antiglycemic efficacy in addition to cardiovascular (CV) safety, which has to be determined in appropriately designed CV outcome trials as mandated by regulatory agencies. Available evidence is largely supportive of metformin's CV safety and potential CVD risk reduction effects, whereas sulfonylureas are either CV risk neutral or are associated with variable CVD risk. Pioglitazone was also associated with improved CVD risk in patients with diabetes. The more recent antihyperglycemic medications have shown promise with regards to CVD risk reduction in T2DM patients at a high CV risk. Glucagon-like peptide-1 receptor agonists, a type of incretin-based therapy, were associated with better CV outcomes and mortality in T2DM patients, leading to the Food and Drug Administration approval of liraglutide to reduce CVD risk in high-risk T2DM patients. Ongoing and planned randomized controlled trials of the newer drugs should clarify the possibility of class effects, and of CVD risk reduction benefits in low-moderate CV risk patients. While metformin remains the first-line antiglycemic therapy in T2DM, glucagon-like peptide-1 receptor agonists should be appropriately prescribed in T2DM patients with baseline CVD or in those at a high CVD risk to improve CV outcomes. Dipeptidyl peptidase-4 inhibitors and sodium-glucose cotransporter-2 inhibitors are discussed in the second part of this review.

Th17/Treg Imbalance and Atherosclerosis

Atherosclerosis is nowadays recognized as a chronic inflammatory disease of large arteries. In recent years, cellular and molecular biology studies on atherosclerosis confirmed that the occurrence and development are related to inflammation and autoimmunity. A variety of immune cells, cytokines, and transcription factors are involved in this process. Current studies found that T helper cell 17, regulatory T cells, and their cytokines play an important role in the development of atherosclerosis and vulnerable plaque rupture. Here, we provide a review of the up-to-date applications of T helper cell 17, regulatory T cells, cytokines, and their balance in the prognosis and therapy of atherosclerosis.

ApoE deficiency promotes hepatic pathology by aggravating Th17/Treg imbalance in murine schistosomiasis japonica

AIMS

The Schistosoma japonicum (S japonicum)-infected ApoE gene deficiency (ApoE^-/- ) mice were used to determine effect of ApoE on hepatic immunopathology.

METHODS

Murine activities and appetite, body weight, and ratio of liver weight to its body weight (Hepatic mass index, HMI) were observed. Worm load and liver egg burden were evaluated as the infection intensity. Number and size of liver egg granulomas and serum levels of alanine aminotransferase (ALT) were investigated. We analysed hepatic fibrosis by markers of fibrosis in tissue, detected hepatic Th17 and Treg frequency by flow cytometry, and measured hepatic expressions of RORγt, Foxp3, IL-17A and TGF-β1 via qPCR. Lipid metabolism was determined by serum levels of cholesterol (TC) and triglyceride (TG) as well as hepatic Oil red O staining.

RESULTS

In the infected ApoE^-/- mice, the increased infection intensity aggravated the hepatic immunopathology (evidenced by increased HMI, elevated egg granulomas and increased ALT levels) and fibrosis (increased hepatic collagen deposition). ApoE deficiency resulted in significantly elevated ratio of hepatic Th17/Treg and higher serum levels of TC and TG, along with higher level of hepatic Oil red O staining.

CONCLUSIONS

ApoE deficiency promotes hepatic pathology and fibrosis by exacerbating Th17/Treg imbalance and altering lipid metabolism in murine schistosomiasis japonica.

Metformin as a Potential Agent in the Treatment of Multiple Sclerosis

Metformin, a synthetic derivative of guanidine, is commonly used as an oral antidiabetic agent and is considered a multi-vector application agent in the treatment of other inflammatory diseases. Recent studies have confirmed the beneficial effect of metformin on immune cells, with special emphasis on immunological mechanisms. Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by various clinical courses. Although the pathophysiology of MS remains unknown, it is most likely a combination of disturbances of the immune system and biochemical pathways with a disruption of blood-brain barrier (BBB), and it is strictly related to injury of intracerebral blood vessels. Metformin has properties which are greatly desirable for MS therapy, including antioxidant, anti-inflammatory or antiplatelet functions. The latest reports relating to the cardiovascular disease confirm an increased risk of ischemic events in MS patients, which are directly associated with a coagulation cascade and an elevated pro-thrombotic platelet function. Hence, this review examines the potential favourable effects of metformin in the course of MS, its role in preventing inflammation and endothelial dysfunction, as well as its potential antiplatelet role.

The proportion of peripheral blood Tregs among the CD4+ T cells of autoimmune thyroid disease patients: a meta-analysis

Autoimmune thyroid disease (AITD) is characterized by a loss of self-tolerance to thyroid antigen. Tregs, whose proportions are controversial among CD4+ T cell from AITD patients (AITDs), are crucial in immune tolerance. Considering that drugs might affect Treg levels, we assumed that the differences originated from different treatment statuses. Thus, we performed a meta-analysis to explore proportions of Tregs in untreated and treated AITDs. PubMed, Embase and ISI Web of Knowledge were searched for relevant studies. Review Manager 5.3 and Stata 14.0 were used to conduct the meta-analysis. Subgroup analysis based on different diseases and cell surface markers was performed. Egger linear regression analysis was used to assess publication bias. Approximately 1,100 AITDs and healthy controls (HCs) from fourteen studies were included. Proportions of Tregs among CD4+ T cells of untreated AITDs were significantly lower than those in HCs (p = 0.002), but were not in treated patients (p = 0.40). Subgroup analysis revealed lower proportions of Tregs in untreated Graves' disease patients (GDs) (p = 0.001) but did not show obvious differences in untreated Hashimoto's thyroiditis patients (HTs) (p = 0.62). Furthermore, proportions of circulating FoxP3+ Tregs were reduced in untreated GDs (p < 0.00001) and HTs (p = 0.04). No publication bias was found. In this first meta-analysis exploring proportions of circulating Tregs among CD4+ T cells of AITDs with different treatment statuses, we found that Tregs potentially contribute to the pathogenesis of AITD but function differently in GD and HT. Remarkably, FoxP3+ Tregs, which were decreased in both diseases, might be promising targets for novel therapies.

Aged garlic extract reduces low attenuation plaque in coronary arteries of patients with diabetes: A randomized, double-blind, placebo-controlled study

Several previous studies have demonstrated that aged garlic extract (AGE) inhibits the progression of coronary artery calcification and non-calcified plaque (NCP) in the general population. However, its effects on plaque progression in patients with diabetes have not yet been investigated, at least to the best of our knowledge. This study investigated whether AGE reduces the coronary plaque volume measured by cardiac computed tomography angiography (CCTA) in patients with diabetes mellitus (DM). A total of 80 participants with DM with a median age of 57 years were prospectively assigned to consume 2,400 mg AGE/day (after completion, 37 participants) or placebo (after completion, 29 participants) orally. Both groups underwent CCTA at baseline and follow-up 365 days apart. In total, 66 participants completed the study. Coronary plaque volume, including total plaque (TP), dense calcium (DC), fibrous, fibro-fatty and low-attenuation plaque (LAP) volumes were measured based upon pre-defined intensity cut-off values using semi-automated software (QAngio CT). Changes in various plaque types were normalized to the total coronary artery length. The non-parametric Wilcoxon rank-sum test was performed to examine the differences in plaque formation between the 2 groups. No significant differences were found in the baseline characteristics between the AGE and placebo groups. Compared with the placebo group, the AGE group exhibited a statistically significant regression in normalized LAP [median and standard deviation (SD) -0.2 (18.8) vs. 2.5 (69.3), P=0.0415]. No differences were observed in TP, fibrous, or fibrofatty plaque volumes between the AGE and placebo group. On the whole, this study indicated that the %LAP change in the AGE group was significantly greater than that in the placebo group in patients with diabetes. However, further studies are warranted to evaluate whether AGE has the ability to stabilize vulnerable plaque and decrease adverse cardiovascular events.

Anti-Atherosclerosis Effect of Angong Niuhuang Pill via Regulating Th17/Treg Immune Balance and Inhibiting Chronic Inflammatory on ApoE-/- Mice Model of Early and Mid-Term Atherosclerosis

Angong Niuhuang Pill (ANP) is a well-known patented Chinese medicine which is used for hundreds of years for treating the central nervous system diseases. Atherosclerosis is a poly-aetiological chronic inflammatory vascular disease. Preventing inflammation is fundamental for treating atherosclerosis in early stages. In this study, we investigated the protective effects and possible mechanisms of ANP action on a high-fat diet induced early and mid-term atherosclerosis ApoE^-/- mice. The effects of ANP were compared with accepted drug simvastatin. Twelve male C57BL/6J mice were used as the control group, and 60 male ApoE^-/- mice were randomly divided into five groups: Model group, Simvastatin group, Low-, Medium-, and High-dose ANP group these groups received, respectively, saline, simvastatin (3.0mg/kg), low-dose ANP (0.25 g/kg), medium-dose ANP (0.50 g/kg), and high-dose ANP (1.0 g/kg), once every other day for 10 weeks. After administration, serum biochemical indices were detected by the automatic biochemical analyzer, the concentrations of IL-6 and IL-10 in the serum were assayed by ELISA, expression levels of IL-1β, TNF-α, MMP-2, MMP-9, CCL2, and its receptor CCR2 in the full-length aorta, and expression levels of transcription factors Foxp3, RORγt in the spleen were assayed via western blotting and RT-qPCR. Flow cytometry was used to analyze Th17 cells and Treg cells. Pathological and histological analysis was completed on aortic root. ANP decreased LDL/HDL ratio, concentrations of IL-6 while increased IL-10 in serum. Moreover, ANP down-regulated the expression levels of IL-1β, TNF-α, MMP-2, MMP-9, CCL2, and CCR2 receptor in the full-length aorta. In addition, ANP decreased Th17 cells and expression levels of transcription factor RORγt, increased Treg cells and expression levels of transcription factor Foxp3. ANP decreased content of collagen fibers and infiltration of inflammatory cells in the aortic root. In conclusion, we demonstrated that ANP has anti-atherosclerosis effects on a high-fat diet induced ApoE^-/- mice early and mid-term AS model via regulating Th17/Treg balance, inhibiting chronic inflammation, reducing plaque collagen fibers, and reducing inflammatory cells infiltration, to exert its multi-channel multi-target anti-early and mid-term AS effects.

MicroRNA let-7g-5p alleviates murine collagen-induced arthritis by inhibiting Th17 cell differentiation

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease with complicated pathogenesis. IL-17-producing T helper cells (Th17) are important players in the RA process. Despite numerous researches have proven that microRNAs (miRNAs) are crucial to regulate autoimmune diseases including RA, the effect of miRNAs on Th17 cell differentiation and function in the RA progress is not clear. Here, our results showed that the expression of miRNA let-7g-5p was substantially lower in RA patients and CIA mice compared with healthy controls, accompanied by the increased Th17 cell population. Furthermore, the inhibition of let-7g-5p on Th17 cell differentiation and function were verified in vitro. Notably, the disease severity in CIA mice was significantly alleviated after the treatment of let-7g-5p mimics. In addition, let-7g-5p mimics treatment markedly down-regulated the frequency of Th17 cells in CIA mice. Taken together, our findings indicate that let-7g-5p can ameliorate CIA through blocking the differentiation of Th17 cells, which may be a novel strategy to treat autoimmune diseases such as RA.

Chloroquine modulates inflammatory autoimmune responses through Nurr1 in autoimmune diseases

For over a half-century the anti-malarial drug chloroquine (CQ) has been used as a therapeutic agent, alone or in combination, to treat autoimmune diseases. However, neither the underlying mechanism(s) of action nor their molecular target(s) are well defined. The orphan nuclear receptor Nurr1 (also known as NR4A2) is an essential transcription factor affecting the development and maintenance of midbrain dopaminergic neurons. In this study, using in vitro T cell differentiation models, we demonstrate that CQ activates T_REG cell differentiation and induces Foxp3 gene expression in a Nurr1-dependent manner. Remarkably, CQ appears to induce Nurr1 function by two distinct mechanisms: firstly, by direct binding to Nurr1’s ligand-binding domain and promoting its transcriptional activity and secondly by upregulation of Nurr1 expression through the CREB signaling pathway. In contrast, CQ suppressed gene expression and differentiation of pathogenic T_H17 cells. Importantly, using a valid animal model of inflammatory bowel disease (IBD), we demonstrated that CQ promotes Foxp3 expression and differentiation of T_REG cells in a Nurr1-dependent manner, leading to significant improvement of IBD-related symptoms. Taken together, these data suggest that CQ ameliorates autoimmune diseases via regulating Nurr1 function/expression and that Nurr1 is a promising target for developing effective therapeutics of human inflammatory autoimmune diseases.

Pioglitazone abrogates testicular damage induced by testicular torsion/detorsion in rats

OBJECTIVES

Testicular torsion/detorsion (T/D) is a well-known cause for infertility. Pioglitazone is an agonist of peroxisome proliferator activated receptor-gamma (PPAR-γ). Previous studies have shown that pioglitazone has anti-inflammatory, antioxidant and antiapoptotic properties. The present study hypothesized that pioglitazone may be protective against the testicular T/D tissue insults, and the possible pathophysiological mechanisms involved in this effect were also investigated.

MATERIALS AND METHODS

Rats were randomly divided into four groups: sham group, T/D group where testicular torsion was performed for 4 hr followed by 4 hr of detorsion and two pioglitazone-treated groups (1 mg/kg and 3 mg/kg, by single intraperitoneal injection 30 min prior to detorsion). At the end of reperfusion period, blood, ipsilateral and contralateral testicular tissue samples were obtained for biochemical and histopathological examination.

RESULTS

Pioglitazone reduced oxidative tissue damages, inflammatory mediators, and apoptotic markers and enhanced the total antioxidant status, and AMP-activated protein kinase level. Moreover, pioglitazone improved spermatogenesis evidenced by increased Johnsen's score and reversed the histopathological damages induced by testicular T/D. The effects of pioglitazone were higher with the dose of 3 mg/kg.

CONCLUSION

Pioglitazone exhibited a protective effect against the deleterious actions of testicular T/D. This beneficial potential of pioglitazone may be attributed to its antioxidant, anti-inflammatory and antiapoptotic properties, which was more obvious with the dose of 3 mg/kg. Pioglitazone may be a promising therapy for testicular T/D.

Effect of the hyaluronic acid-poloxamer hydrogel on skin-wound healing: in vitro and in vivo studies

BACKGROUND

Recent research into skin injury and wound healing has focused mainly on post-trauma hemostasis, infection prevention, dermal regeneration and angiogenesis. However, less attention has been paid to air permeability and moisture loss prevention which also play important roles in injury healing.

METHODS

In the present work, we prepared a hyaluronic acid-poloxamer (HA-POL) hydrogel and tested the therapeutic effect of the hydrogel on skin-wound healing.

RESULTS

The HA-POL hydrogel transformed from sol to gel at 30°C, close to body temperature, and had stable moisturizing properties. HA-POL hydrogel promoted skin-wound healing and increased protein accumulation in the wound area. HA-POL hydrogel allowed greater air permeability than Band-aid, a typical wound covering. Results from transwell assays showed that the HA-POL hydrogel effectively isolated skin-wounds from bacterial invasion.

CONCLUSION

This work demonstrates the advantages of using HA-POL gel materials in the treatment of cutaneous wounds.

Effect of pioglitazone in acute ischemic stroke patients with diabetes mellitus: a nested case-control study

Background

Pioglitazone is an oral antidiabetic drug with multiple pleiotropic actions. Recent clinical trials have demonstrated that treatment with pioglitazone reduces cardiovascular risk in patients who have had an ischemic stroke. We examined the secondary preventive effects of pioglitazone in acute ischemic stroke patients with diabetes mellitus (DM) based on nationwide real-world data.

Methods

A nested case–control study was conducted with data from the National Health Insurance Service-National Sample Cohort in Korea. Study subjects were diabetic patients admitted for acute ischemic stroke (ICD-10 code; I63) between 2002 and 2013. Cases were defined as patients who suffered from composites of recurrent stroke (I60–63), myocardial infarction (I21), or all-cause mortality after ischemic stroke. Controls were selected by incidence density sampling. Three controls were matched to each case for sex, age, treatment with insulin, and oral antidiabetic medications, with the exception of pioglitazone. Medication history after ischemic stroke was obtained by accessing the prescription records. In the matched dataset, conditional logistic regression analysis was performed with adjustments for hypertension, atrial fibrillation, prior myocardial infarction, and treatment with oral antithrombotics and statins.

Results

From the patients with acute ischemic stroke and DM, 1150 cases with primary outcomes were matched to 3450 controls. In the matched analysis, treatment with pioglitazone was significantly associated with a lower cardiovascular risk (adjusted OR [95% CI], 0.43 [0.23–0.83]).

Conclusions

In this nested case–control study using real-world data, treatment with pioglitazone exhibited significant cardiovascular preventive effect in diabetic patients with acute ischemic stroke.

Pioglitazone strengthen therapeutic effect of adipose-derived regenerative cells against ischemic cardiomyopathy through enhanced expression of adiponectin and modulation of macrophage phenotype

Background

The efficacy of cell transplantation in heart failure is reportedly modest, but adjuvant drugs combined with cell therapy may improve this efficacy. Peroxisome proliferator-activated receptor (PPAR)γ, one of the hypoglycemic medicine for diabetes mellitus, reportedly enhances cytokine production in adipose tissue-derived regenerative cells (ADRCs). We hypothesized that combined administration of PPARγ agonists and ADRCs may enhance the paracrine effects of adiponectin (APN), leading to functional recovery in a chronic myocardial infarction (MI) model.

Methods

ADRCs were isolated from adipose tissues of adult rats by gradient centrifugation and embedded in bio-compatible fibrin-glue to produce ADRCs grafts. In the in vitro study, the ADRCs grafts released APN, which was significantly enhanced by the PPARγ agonist (PGZ, pioglitazone). Transplantation of ADRCs grafts (group A), ADRCs mixed with PGZ (group AP), APN knockdown-ADRCs (group Si) or PGZ (group P) onto the epicardium or a sham operation (group C) was performed (n = 10–20 per group).

Results

The AP group showed significant improvement in ejection fraction compared to that in the other groups. In the AP group, a significantly larger number of M2-polarized macrophages was detected and existed for a significantly longer duration in the infarct area. Furthermore, comparing Si group and P group, western blotting of T-cadherin revealed that exogenous APN and local expression of T-cadherin were essential to this histological change and recovery of cardiac function.

Conclusions

Combined administration of PPARγ agonist and ADRSCs activated M2-polarized macrophages with enhancement of APN paracrine effects and lead to better cardiac function in a rat infarction model.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0829-x) contains supplementary material, which is available to authorized users.

Pulmonary arterial remodelling by deficiency of peroxisome proliferator-activated receptor-γ in murine vascular smooth muscle cells occurs independently of obesity-related pulmonary hypertension

Background

Obesity is associated with cardiovascular complications, including pulmonary hypertension (PH). Reports suggest that peroxisome proliferator-activated receptor-γ (PPARγ) has direct action in preventing vascular remodelling in PH. Here we dissected the specific role of high-fat-diet (HFD)-induced obesity and vascular smooth muscle cell (VSMC)-PPARγ for remodelling of small pulmonary arteries.

Methods

Wild-type (WT) and VSMC-specific PPARγ-knockout (SmPparγ^−/−) mice were fed a low-fat-diet (LFD, 10% kcal from fat) or HFD (60% kcal from fat) for 24 weeks. Mice were metabolically phenotyped (e.g. weight development, insulin/glucose tolerance) at the beginning, and after 12 and 24 weeks, respectively. At 24 weeks additionally pulmonary pressure, heart structure, pulmonary vascular muscularization together with gene and protein expression in heart and lung tissues were determined.

Results

HFD increased right ventricular systolic pressure (RVSP) to a similar extent in WT and SmPparγ^−/− mice. HFD decreased glucose tolerance and insulin sensitivity in both WT and SmPparγ^−/− mice. Importantly, the increase in RVSP correlated with the degree of insulin resistance. However, VSMC-PPARγ deficiency increased pulmonary vascular muscularization independently of the diet-induced rise in RVSP. This increase was associated with elevated expression of early growth response protein 1 in heart and osteopontin in lung tissue.

Conclusions

Here we demonstrate a correlation of insulin resistance and pulmonary pressure. Further, deficiency of PPARγ in VSMCs diet-independently leads to increased pulmonary vascular muscularization.

NLRP3 inflammasome promotes diabetes-induced endothelial inflammation and atherosclerosis

BACKGROUND

NLRP3 inflammasome can be activated by high glucose and links inflammation and metabolic disease. This study aimed to investigate the role of NLRP3 inflammasome in hyperglycemia-induced endothelial inflammation and diabetic atherosclerosis.

METHODS

NLRP3 levels in peripheral blood mononuclear cell (PBMC) and plasma IL-1β level were measured in diabetes patients. The activation of NLPR3 was detected in diabetic ApoE-/- mice and human umbilical vein endothelial cells (HUVECs).

RESULTS

Compared with healthy controls, NLRP3 expression levels in PBMC and plasma IL-1β level were significantly higher in diabetes patients but considerably decreased after lifestyle interventions and medicine. Moreover, carotid atherosclerosis was significantly related to plasma IL-1β level in diabetes patients. In diabetic atherosclerosis mouse model, NLRP3 knockdown suppressed NLRP3 inflammasome activation, inhibited the expression of adhesion molecules ICAM-1 and VCAM-1 in intima, reduced atherosclerosis and stabilized atherosclerotic plaque. In vitro, the expression of NLRP3 inflammasome components and the secretion of IL-1β were augmented by high glucose in HUVECs. Moreover, either high glucose or IL-1β promoted the expression of adhesion molecules, which were suppressed by NLRP3 knockdown or IL-1β receptor antagonist.

CONCLUSION

These findings provide novel insights into pathological mechanisms of diabetic atherosclerosis and have potential therapeutic implications for cardiovascular complications in diabetes.

The expression and clinical correlations of 4-1BB on peripheral CD4+ T cell subsets in patients with coronary artery disease. A cross-sectional pilot study

BACKGROUND

The expression of 4-1BB on peripheral regulatory T cells (Tregs) and conventional T cells (Tconvs) in coronary artery disease (CAD) patients is unknown. We aimed to investigate the expression and clinical correlations of 4-1BB on peripheral Tregs and Tconvs in CAD patients.

METHODS

Flow cytometry analysis was used to analyze 4-1BB expression on peripheral Tregs and Tconvs. We compared the percentages of 4-1BB on Tregs and Tconvs in the control (ctrl) group, the stable ischemic heart disease (SIHD) group, and the acute coronary syndrome (ACS) group. The correlations of 4-1BB expression on Tregs and Tconvs with the Gensini score and CRP were examined in the ACS group. The value of 4-1BB percentage on Tregs for predicting CAD in this cardiovascular risk population was also analyzed.

RESULTS

A total of 71 participants were enrolled in this study. In all the groups, the percentages of 4-1BB on Tregs were significantly higher than on Tconvs (all P < .05). After adjusting for sex, age, SBP, HbA1c and LDL, 4-1BB percentages on Tregs and Tconvs were significantly higher in the SIHD and ACS groups compared with the ctrl group (all P < .05). The ratio of 4-1BB percentage on Tregs to 4-1BB percentage on Tconvs was higher in the ACS group compared with the ctrl group (P = .010). In the ACS group, CRP was negatively correlated with the Tregs percentage (in CD4+ T cells) and the Tregs percentage to Tconvs percentage ratio. The Gensini score was positively correlated with the 4-1BB percentage on Tregs in the ACS group. Linear regression analysis showed 4-1BB percentage on Tregs independently predicted the Gensini score. Binary logistic regression showed CRP, HbA1c and 4-1BB percentage on Tregs independently predicted the development of CAD (SIHD+ACS) in the whole population.

CONCLUSION

4-1BB expression on peripheral Tregs and Tconvs was increased in SIHD and ACS patients. 4-1BB percentage on Tregs positively correlated with the severity of coronary artery stenosis in ACS patients. 4-1BB percentage on Tregs independently predicted the severity of coronary artery stenosis in an ACS population and development of CAD in a cardiovascular risk population.

Glitazones and alpha-glucosidase inhibitors as the second-line oral anti-diabetic agents added to metformin reduce cardiovascular risk in Type 2 diabetes patients: a nationwide cohort observational study

Objective

Metformin is the standard first-line drug for patients with Type 2 diabetes (T2DM). However, the optimal second-line oral anti-diabetic agent (ADA) remains unclear. We investigated the cardiovascular risk of various ADAs used as add-on medication to metformin in T2DM patients from a nationwide cohort.

Methods

T2DM patients using different add-on oral ADAs after an initial metformin therapy of > 90 days were identified from the Taiwan National Health Insurance Database. Five classes of ADAs, including sulphonylureas (SU), glinides, thiazolidinediones (TZD), alpha-glucosidase inhibitors (AGI), and dipeptidyl peptidase-4 inhibitors (DPP-4I) were selected for analysis. The reference group was the SU added to metformin. Patients were excluded if aged < 20 years, had a history of stroke or acute coronary syndrome (ACS), or were receiving insulin treatment. The primary outcomes included any major adverse cardiovascular event (MACE) including ACS, ischemic/hemorrhagic stroke, and death. A Cox regression model was used to estimate the hazard ratio (HR) for MACE.

Results

A total of 26,742 patients receiving their add-on drug to metformin of either SU (n = 24,277), glinides (n = 962), TZD (n = 581), AGI (n = 808), or DPP-4I (n = 114) were analyzed. After a mean follow-up duration of 6.6 ± 3.4 years, a total of 4775 MACEs occurred. Compared with the SU+metformin group (reference), the TZD+metformin (adjusted HR: 0.66; 95% CI 0.50–0.88, p = 0.004) and AGI+metformin (adjusted HR: 0.74; 95% CI 0.59–0.94, p = 0.01) groups showed a significantly lower risk of MACE.

Conclusion

Both TZD and AGI, when used as an add-on drug to metformin were associated with lower MACE risk when compared with SU added to metformin in this retrospective cohort study.

Trial registration CE13152B-3. Registered 7 Mar, 2013, retrospectively registered

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0663-6) contains supplementary material, which is available to authorized users.