Macrophage adiponectin expression improves insulin sensitivity and protects against inflammation and atherosclerosis

Adiponectin alleviates inflammatory response in metabolic dysfunction-associated steatohepatitis by inhibiting NLRP3 inflammasome-mediated hepatocyte pyroptosis

BACKGROUND

Activation of NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasomes induced by pyroptosis is crucial in metabolic dysfunction-associated steatohepatitis (MASH) progression. Adiponectin possesses an anti-inflammatory role in various liver diseases. This study aimed to evaluate the effects of adiponectin on MASH.

METHODS

Adiponectin-mediated anti-inflammatory mechanisms, effects on pyroptosis-related proteins, and activation of NLRP3 inflammasomes were investigated using methionine-choline-deficient (MCD)-induced MASH murine model and in vitro models. The degree of MASH inflammation in liver tissue of C57BL/6J mice was assessed using histopathology. Enzyme-linked immunosorbent assay was performed to measure levels of inflammatory factors [interleukin-18 (IL-18), IL-1β, and tumor necrosis factor-α (TNF-α)] in mice serum and culture medium. Western blot and quantitative polymerase chain reaction were performed to analyze the expression of pyroptosis-related genes and proteins in liver tissues of mouse model and in vitro models. Macrophage recruitment in vitro was evaluated using co-culture of upper and lower chambers.

RESULTS

MASH developed in MCD diet mice [metabolic dysfunction-associated steatotic liver disease (MASLD) activity score = 6] but not in methionine-choline-sufficient (MCS) diet mice (MASLD activity score = 3). Compared to MCS-fed mice, MCD-fed mice showed increased serum levels of aspartate aminotransferase, IL-18, IL-1β, and TNF-α and higher MASLD activity score (P < 0.001). Adiponectin inhibited these increases (P < 0.05) and suppressed mRNA and protein levels of NLRP3, gasdermin-D (GSDMD), and GSDMD-N in liver tissues (P < 0.05). In vitro, lipopolysaccharide (LPS)/palmitic acid (PA) increased the levels of IL-18, IL-1β, and TNF-α, mRNA expressions of CASP1 and GSDMD, and production of CASP1, NLRP3, GSDMD, and GSDMD-N (P < 0.01). Adiponectin reduced the levels of these inflammatory factors and downregulated the mRNA expression and protein generation of pyroptosis-related markers (P < 0.05). HepG2 cells pretreated with LPS/PA recruited more J774A.1 cells (P < 0.001) and increased inflammatory factor secretion by J774A.1 cells (P < 0.001). Adiponectin inhibited this recruitment and reduced inflammatory factor secretion (P < 0.001).

CONCLUSIONS

Adiponectin inhibits hepatocyte pyroptosis by reducing the production and activation of NLRP3 inflammasomes, CASP1, and GSDMD, thus improving the inflammatory response in MASH and possibly delaying or reversing MASLD progression.

Single-cell view and a novel protective macrophage subset in perivascular adipose tissue in T2DM

BACKGROUND

Vasculopathy underlies diabetic complications, with perivascular adipose tissue (PVAT) playing crucial roles in its development. However, the changes in the cellular composition and function of PVAT, including the specific cell subsets and mechanisms implicated in type 2 diabetes mellitus (T2DM) vasculopathy, remain unclear.

METHODS

To address the above issues, we performed single-cell RNA sequencing on the stromal vascular fraction (SVF) of PVAT from normal and T2DM rats. Then, various bioinformatics tools and functional experiments were used to investigate the characteristic changes in the cellular profile of diabetic PVAT SVF, their implications, and the underlying mechanisms.

RESULTS

Our study reveals the single-cell landscape of the SVF of PVAT, demonstrating its considerable heterogeneity and significant alterations in T2DM, including an enhanced inflammatory response and elevated proportions of macrophages and natural killer (NK) cells. Moreover, macrophages are critical hubs for cross-talk among various cell populations. Notably, we identified a decreased Pdpn+ macrophage subpopulation in the PVAT of T2DM rats and confirmed this in mice and humans. In vitro and in vivo studies demonstrated that Pdpn+ macrophages alleviated insulin resistance and modulated adipokine/cytokine expression in adipocytes via the Pla2g2d-DHA/EPA-GPR120 pathway. This subset also enhances the function of vascular endothelial and smooth muscle cells, inhibits vascular inflammation and oxidative stress, and improves vasodilatory function, thereby protecting blood vessels.

CONCLUSION

Pdpn+ macrophages exhibit significant vascular protective effects by alleviating insulin resistance and modulating adipokine/cytokine expression in PVAT adipocytes. This macrophage subtype may therefore play pivotal roles in mitigating vascular complications in T2DM. Our findings also underscore the critical role of immune-metabolic cross-talk in maintaining tissue homeostasis.

Effects of germinated brown rice and germinated black rice on people with type 2 diabetes mellitus combined with dyslipidaemia

Objective: This study aimed to observe the effects of germinated brown rice and germinated black rice on blood lipid levels, blood glucose levels and lipid metabolism-related enzymes in T2DM patients with dyslipidaemia and to study their effects on the gut microbiome and short-chain fatty acids. Methods: According to the inclusion and exclusion criteria, 68 subjects were randomly divided into a germinated brown rice group, a germinated black rice group and a white rice group. At the end of the intervention, relevant anthropometric indices, blood biochemistry, and levels of adipokines and lipid metabolism-related enzymes were measured. Faecal samples were collected for 16S rDNA high-throughput sequencing and for an analysis of short-chain fatty acids. Results: After 3 months of intervention with germinated brown rice, germinated black rice or white rice, 21 people in each group completed the intervention as required. At the end of the intervention, the levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the germinated brown rice group and germinated black rice group were significantly lower than those in the white rice group. The levels of adiponectin (ADPN) and lecithin cholesterol acyltransferase (LCAT) in the germinated brown rice group were significantly higher than those in the white rice group (P < 0.05). At the genus level, interventions with germinated brown rice and germinated black rice significantly increased the relative abundance of Megamonas, Muribaculaceae and Alloprevotella and significantly decreased the relative abundance of Veillonella (P < 0.05). After 3 months of intervention, a significant decrease in waist circumference was observed within the germinated brown rice group compared to that at baseline (P < 0.05). Conclusions: Compared with the consumption of white rice, the consumption of germinated brown rice and germinated black rice can effectively regulate the glucose and lipid metabolism of this population. In addition, interventions involving the use of germinated brown rice and germinated black rice may further improve intestinal diversity and abundance, increase the relative abundance of Megamonas and decrease the relative abundance of Veillonella.

Evaluating the Diagnostic Potential of Serum Vascular Endothelial Growth Factor and Adiponectin in Diabetic Peripheral Neuropathy

INTRODUCTION

Diabetic peripheral neuropathy (DPN) presents a formidable health challenge in type 2 diabetes mellitus (T2DM) patients. This study in eastern Uttar Pradesh aims to assess the roles of vascular endothelial growth factor (VEGF) and adiponectin in DPN, recognizing the crucial need for understanding its molecular underpinnings for enhanced diagnosis and management.

METHODS

In a cross-sectional study analyzing clinical and biochemical data, 86 individuals aged 35 to 65 years were examined, including 43 with neuropathy and 43 without. Neuropathy assessment included the neuropathy symptom score (NSS), diabetes neuropathy examination (DNE) score, and nerve conduction studies. Levels of VEGF and adiponectin were correlated with motor nerve amplitude, NSS, and DNE scores. Receiver operating characteristic (ROC) curve analysis gauged diagnostic potential, and logistic regression assessed predictors for DPN.

RESULTS

Patients with neuropathy exhibited significantly elevated VEGF levels compared to those without, while adiponectin showed no significant difference. VEGF demonstrated a negative correlation with motor nerve amplitude and a positive correlation with NSS and DNE scores. ROC analysis revealed strong diagnostic capability for VEGF (area under the curve: 0.807). NSS and DNE scores indicated good and moderate diagnostic accuracy, respectively. In logistic regression analysis, VEGF emerged as the sole significant predictor (odds ratio: 1.11, 95% CI (1.03, 1.20), p = 0.0092).

CONCLUSION

Findings suggest VEGF's potential as a biomarker for diagnosing DPN in T2DM, associated with neuropathy severity. Adiponectin showed no significant association. The study underscores NSS and DNE scores' therapeutic relevance as valid neuropathy assessment tools.

Nutrient-sensing growth hormone secretagogue receptor in macrophage programming and meta-inflammation

OBJECTIVE

Obesity-associated chronic inflammation, aka meta-inflammation, is a key pathogenic driver for obesity-associated comorbidity. Growth hormone secretagogue receptor (GHSR) is known to mediate the effects of nutrient-sensing hormone ghrelin in food intake and fat deposition. We previously reported that global Ghsr ablation protects against diet-induced inflammation and insulin resistance, but the site(s) of action and mechanism are unknown. Macrophages are key drivers of meta-inflammation. To unravel the role of GHSR in macrophages, we generated myeloid-specific Ghsr knockout mice (LysM-Cre;Ghsrf/f).

METHODS

LysM-Cre;Ghsrf/f and control Ghsrf/f mice were subjected to 5 months of high-fat diet (HFD) feeding to induce obesity. In vivo, metabolic profiling of food intake, physical activity, and energy expenditure, as well as glucose and insulin tolerance tests (GTT and ITT) were performed. At termination, peritoneal macrophages (PMs), epididymal white adipose tissue (eWAT), and liver were analyzed by flow cytometry and histology. For ex vivo studies, bone marrow-derived macrophages (BMDMs) were generated from the mice and treated with palmitic acid (PA) or lipopolysaccharide (LPS). For in vitro studies, macrophage RAW264.7 cells with Ghsr overexpression or Insulin receptor substrate 2 (Irs2) knockdown were studied.

RESULTS

We found that Ghsr expression in PMs was increased under HFD feeding. In vivo, HFD-fed LysM-Cre;Ghsrf/f mice exhibited significantly attenuated systemic inflammation and insulin resistance without affecting food intake or body weight. Tissue analysis showed that HFD-fed LysM-Cre;Ghsrf/f mice have significantly decreased monocyte/macrophage infiltration, pro-inflammatory activation, and lipid accumulation, showing elevated lipid-associated macrophages (LAMs) in eWAT and liver. Ex vivo, Ghsr-deficient macrophages protected against PA- or LPS-induced pro-inflammatory polarization, showing reduced glycolysis, increased fatty acid oxidation, and decreased NF-κB nuclear translocation. At molecular level, GHSR metabolically programs macrophage polarization through PKA-CREB-IRS2-AKT2 signaling pathway.

CONCLUSIONS

These novel results demonstrate that macrophage GHSR plays a key role in the pathogenesis of meta-inflammation, and macrophage GHSR promotes macrophage infiltration and induces pro-inflammatory polarization. These exciting findings suggest that GHSR may serve as a novel immunotherapeutic target for the treatment of obesity and its associated comorbidity.

Linking Adiponectin and Its Receptors to Age-Related Macular Degeneration (AMD)

In recent years, there has been a captivating focus of interest in elucidating the intricate crosstalk between adiponectin (APN), a versatile fat-associated adipokine and ocular pathologies. Unveiling the intricate relationship between adipocytokine APN and its receptors (AdipoRs) with aging eye disorders has emerged as a fascinating frontier in medical research. This review article delves into this connection, illuminating the hidden influence of APN on retinal health. This comprehensive review critically examines the latest findings and breakthroughs that underscore the pivotal roles of APN/AdipoRs signaling in maintaining ocular homeostasis and protecting against eye ailments. Here, we meticulously explore the intriguing mechanisms by which APN protein influences retinal function and overall visual acuity. Drawing from an extensive array of cutting-edge studies, the article highlights APN's multifaceted functions, ranging from anti-inflammatory properties and oxidative stress reduction to angiogenic regulation within retinal and macula tissues. The involvement of APN/AdipoRs in mediating these effects opens up novel avenues for potential therapeutic interventions targeting prevalent aging eye conditions. Moreover, this review unravels the interplay between APN signaling pathways and age-related macular degeneration (AMD). The single-cell RNA-seq results validate the expression of both the receptor isoforms (AdipoR1/R2) in retinal cells. The transcriptomic analysis showed lower expression of AdipoR1/2 in dry AMD pathogenesis compared to healthy subjects. The inhibitory adiponectin peptide (APN1) demonstrated over 75% suppression of CNV, whereas the control peptide did not exert any inhibitory effect on choroidal neovascularization (CNV). The elucidation of these relationships fosters a deeper understanding of adipose tissue's profound influence on ocular health, presenting new prospects for personalized treatments and preventative measures. Because APN1 inhibits CNV and leakage, it can be used to treat human AMD, although the possibility to treat human AMD is in the early stage and more clinical research is needed. In conclusion, this review provides a captivating journey into the enthralling world of APN, intertwining the realms of adipose biology and ophthalmology in aging.

Emerging Role of Adiponectin/AdipoRs Signaling in Choroidal Neovascularization, Age-Related Macular Degeneration, and Diabetic Retinopathy

Age-related macular degeneration (AMD), a leading cause of irreversible blindness in adults, may result in poor central vision, making it difficult to see, read, and drive. AMD is generally classified in either dry or wet types. Milder cases of dry AMD may progress to geographic atrophy (GA), leading to significant visual disability; wet, or neovascular AMD, which involves choroidal neovascularization (CNV), can lead to complete loss of central vision. Adiponectin (APN) discovery in the mid-1990's and, subsequently, its two cognate receptors (AdipoRs) in the early 2000s have led to a remarkable progress in better understanding metabolic disorders, as well as metabolism-associated ocular pathology. APN/AdipoRs signaling plays a central role in a variety of molecular and cellular physiological events, including glucose and lipid metabolism, whole-body energy regulation, immune and inflammation responses, insulin sensitivity and retinal cell biological functions. This review is an amalgamation of recent information related to APN/AdipoRs in the pathophysiology of retinal diseases and furthers its association with AMD and diabetic retinopathy. Additionally, we present our original research, where we designed control peptide and CNV inhibitory peptide from the globular region of APN to see the effect of these peptides on the mouse model of laser-induced CNV. The inhibitory peptide (APN1) inhibited CNV by more than 75% while the control peptide did not inhibit CNV.

Regulation of cardiovascular health and disease by visceral adipose tissue-derived metabolic hormones

Visceral adipose tissue (VAT) is a metabolic organ known to regulate fat mass, and glucose and nutrient homeostasis. VAT is an active endocrine gland that synthesizes and secretes numerous bioactive mediators called 'adipocytokines/adipokines' into systemic circulation. These adipocytokines act on organs of metabolic importance like the liver and skeletal muscle. Multiple preclinical and in vitro studies showed strong evidence of the roles of adipocytokines in the regulation of metabolic disorders like diabetes, obesity and insulin resistance. Adipocytokines, such as adiponectin and omentin, are anti-inflammatory and have been shown to prevent atherogenesis by increasing nitric oxide (NO) production by the endothelium, suppressing endothelium-derived inflammation and decreasing foam cell formation. By inhibiting differentiation of vascular smooth muscle cells (VSMC) into osteoblasts, adiponectin and omentin prevent vascular calcification. On the other hand, adipocytokines like leptin and resistin induce inflammation and endothelial dysfunction that leads to vasoconstriction. By promoting VSMC migration and proliferation, extracellular matrix degradation and inflammatory polarization of macrophages, leptin and resistin increase the risk of atherosclerotic plaque vulnerability and rupture. Additionally, the plasma concentrations of these adipocytokines alter in ageing, rendering older humans vulnerable to cardiovascular disease. The disturbances in the normal physiological concentrations of these adipocytokines secreted by VAT under pathological conditions impede the normal functions of various organs and affect cardiovascular health. These adipokines could be used for both diagnostic and therapeutic purposes in cardiovascular disease.

Nicotinamide mononucleotide attenuates HIF-1α activation and fibrosis in hypoxic adipose tissue via NAD+/SIRT1 axis

BACKGROUND

Fibrosis is increasingly considered as a major contributor in adipose tissue dysfunction. Hypoxic activation of hypoxia-inducible factor 1α (HIF-1α) induces a profibrotic transcription, leading to adipose fibrosis. Nicotinamide mononucleotide (NMN), a member of the vitamin B₃ family, has been shown to relieve hepatic and cardiac fibrosis, but its effects on hypoxic adipose fibrosis and the underlying mechanism remain unclear. We aimed to elucidate the roles of NMN in regulating HIF-1α and fibrosis in hypoxic adipose tissue.

METHODS

Mice were placed in a hypobaric chamber for four weeks to induce adipose fibrosis. NMN (500 mg/kg, every three days) was administered by intraperitoneal injection. In vitro, Stromal vascular fractions (SVF) cells were treated by hypoxia with or without NMN (200μM), sirtinol (25μM, a SIRT1 inhibitor) and CoCl₂ (100μM, a HIF1α enhancer). The effects of NMN on hypoxia-associated adipose fibrosis, inflammation, NAD⁺/SIRT1 axis alteration, and HIF-1α activation were evaluated by real-time polymerase chain reaction (PCR), western blots, immunohistochemistry staining, immunoprecipitation, and assay kits.

RESULTS

Mice placed in a hypoxic chamber for four weeks showed obvious adipose fibrosis and inflammation, which were attenuated by NMN. NMN also restore the compromised NAD⁺/SIRT1 axis and inhibited the activation of HIF-1α induced by hypoxia. In hypoxia-induced SVFs, the SIRT1 inhibitor sirtinol blocked the anti-fibrotic and anti-inflammatory effects of NMN, upregulated the HIF-1α and its acetylation level. The HIF1α stabilizer CoCl₂ showed similar effects as sirtinol.

CONCLUSION

NMN effectively attenuated HIF-1α activation-induced adipose fibrosis and inflammation by restoring the compromised NAD⁺/SIRT1 axis.

Genetic Variants of SIRT1 Gene Promoter in Type 2 Diabetes

Type 2 diabetes (T2D) is a highly heterogeneous and polygenic disease. To date, genetic causes and underlying mechanisms for T2D remain unclear. SIRT1, one member of highly conserved NAD-dependent class III deacetylases, has been implicated in many human diseases. Accumulating evidence indicates that SIRT1 is involved in insulin resistance and impaired pancreatic β-cell function, the two hallmarks of T2D. Thus, we speculated that altered SIRT1 levels, resulting from the genetic variants within its regulatory region of SIRT1 gene, may contribute to the T2D development. In this study, the SIRT1 gene promoter was genetically analyzed in T2D patients (n = 218) and healthy controls (n = 358). A total of 20 genetic variants, including 7 single-nucleotide polymorphisms (SNPs), were identified. Five heterozygous genetic variants (g.4114-15InsA, g.4801G > A, g.4816G > C, g.4934G > T, and g.4963_64Ins17bp) and one SNP (g.4198A > C (rs35706870)) were identified in T2D patients, but in none of the controls. The frequencies of two SNPs (g.4540A > G (rs3740051) (OR: 1.75, 95% CI: 1.24-2.47, P < 0.001 in dominant genetic model) and g.4821G > T (rs35995735)) (OR: 3.58, 95% CI: 1.94-6.60, P < 0.001 in dominant genetic model) were significantly higher in T2D patients. Further association and haplotype analyses confirmed that these two SNPs were strongly linked, contributing to the T2D (OR: 1.442, 95% CI: 1.080-1.927, P < 0.05). Moreover, most of the genetic variants identified in T2D were disease-specific. Taken together, the genetic variants within SIRT1 gene promoter might contribute to the T2D development by altering SIRT1 levels. Underlying molecular mechanism needs to be further explored.

Adipokines, adiposity, and atherosclerosis

Characterized by a surplus of whole-body adiposity, obesity is strongly associated with the prognosis of atherosclerosis, a hallmark of coronary artery disease (CAD) and the major contributor to cardiovascular disease (CVD) mortality. Adipose tissue serves a primary role as a lipid-storage organ, secreting cytokines known as adipokines that affect whole-body metabolism, inflammation, and endocrine functions. Emerging evidence suggests that adipokines can play important roles in atherosclerosis development, progression, as well as regression. Here, we review the versatile functions of various adipokines in atherosclerosis and divide these respective functions into three major groups: protective, deteriorative, and undefined. The protective adipokines represented here are adiponectin, fibroblast growth factor 21 (FGF-21), C1q tumor necrosis factor-related protein 9 (CTRP9), and progranulin, while the deteriorative adipokines listed include leptin, chemerin, resistin, Interleukin- 6 (IL-6), and more, with additional adipokines that have unclear roles denoted as undefined adipokines. Comprehensively categorizing adipokines in the context of atherosclerosis can help elucidate the various pathways involved and potentially pave novel therapeutic approaches to treat CVDs.

Intermittent prednisone treatment in mice promotes exercise tolerance in obesity through adiponectin

The fat-muscle communication regulates metabolism and involves circulating signals like adiponectin. Modulation of this cross-talk could benefit muscle bioenergetics and exercise tolerance in conditions like obesity. Chronic daily intake of exogenous glucocorticoids produces or exacerbates metabolic stress, often leading to obesity. In stark contrast to the daily intake, we discovered that intermittent pulses of glucocorticoids improve dystrophic muscle metabolism. However, the underlying mechanisms, particularly in the context of obesity, are still largely unknown. Here we report that in mice with diet-induced obesity, intermittent once-weekly prednisone increased total and high-molecular weight adiponectin levels and improved exercise tolerance and energy expenditure. These effects were dependent upon adiponectin, as shown by genetic ablation of the adipokine. Upregulation of Adipoq occurred through the glucocorticoid receptor (GR), as this effect was blocked by inducible GR ablation in adipocytes. The treatment increased the muscle metabolic response of adiponectin through the CAMKK2-AMPK cascade. Our study demonstrates that intermittent glucocorticoids produce healthful metabolic remodeling in diet-induced obesity.

Monocytes and macrophages in pregnancy: The good, the bad, and the ugly

A successful human pregnancy requires precisely timed adaptations by the maternal immune system to support fetal growth while simultaneously protecting mother and fetus against microbial challenges. The first trimester of pregnancy is characterized by a robust increase in innate immune activity that promotes successful implantation of the blastocyst and placental development. Moreover, early pregnancy is also a state of increased vulnerability to vertically transmitted pathogens notably, human immunodeficiency virus (HIV), Zika virus (ZIKV), SARS-CoV-2, and Listeria monocytogenes. As gestation progresses, the second trimester is marked by the establishment of an immunosuppressive environment that promotes fetal tolerance and growth while preventing preterm birth, spontaneous abortion, and other gestational complications. Finally, the period leading up to labor and parturition is characterized by the reinstatement of an inflammatory milieu triggering childbirth. These dynamic waves of carefully orchestrated changes have been dubbed the "immune clock of pregnancy." Monocytes in maternal circulation and tissue-resident macrophages at the maternal-fetal interface play a critical role in this delicate balance. This review will summarize the current data describing the longitudinal changes in the phenotype and function of monocyte and macrophage populations in healthy and complicated pregnancies.

Gestational Diabetes Mellitus and Maternal Immune Dysregulation: What We Know So Far

Gestational diabetes mellitus (GDM) is an obstetric complication that affects approximately 5-10% of all pregnancies worldwide. GDM is defined as any degree of glucose intolerance with onset or first recognition during pregnancy, and is characterized by exaggerated insulin resistance, a condition which is already pronounced in healthy pregnancies. Maternal hyperglycaemia ensues, instigating a 'glucose stress' response and concurrent systemic inflammation. Previous findings have proposed that both placental and visceral adipose tissue play a part in instigating and mediating this low-grade inflammatory response which involves altered infiltration, differentiation and activation of maternal innate and adaptive immune cells. The resulting maternal immune dysregulation is responsible for exacerbation of the condition and a further reduction in maternal insulin sensitivity. GDM pathology results in maternal and foetal adverse outcomes such as increased susceptibility to diabetes mellitus development and foetal neurological conditions. A clearer understanding of how these pathways originate and evolve will improve therapeutic targeting. In this review, we will explore the existing findings describing maternal immunological adaption in GDM in an attempt to highlight our current understanding of GDM-mediated immune dysregulation and identify areas where further research is required.

L-Threoascorbic acid treatment promotes S. aureus-infected primary human endothelial cells survival and function, as well as intracellular bacterial killing, and immunomodulates the release of IL-1β and soluble ICAM-1

BACKGROUND

Vitamin C (ascorbic acid, AscH2) has been shown to enhance immunity. Here, we studied its immunomodulatory effect on human endothelial cells (ECs) during S. aureus infection.

MATERIALS AND METHODS

The ex vivo effects of AscH2 were performed on primary human umbilical vein endothelial cells (HUVECs) infected or not with S. aureus.

RESULTS

AscH2 treatment induced a marked downregulation of nitric oxide (NO) production and a moderate upregulation of arginase activity in S. aureus-infected HUVECs (respectively, p < 0.05 and p > 0.05). Although the upregulated release levels of soluble intercellular adhesion molecular 1 (sICAM-1/sCD54) and sE-selectin (sCD62E) molecules were not significantly different between treated and untreated S. aureus-infected HUVECs, AscH2 treatment induced reversing effect on sICAM-1 release when comparing to uninfected control HUVECs. Moreover, AscH2 treatment appears to have a significant effect on preventing HUVEC necrosis induced by S. aureus infection (p < 0.05). Furthermore, AscH2 treatment induced a significant upregulation of cell protective redox biomarker in S. aureus-infected, as shown by superoxide dismutase (SOD) activity (p < 0.05), but not by catalase activity (p > 0.05). Additionally, S. aureus infection markedly downregulated total bound calcium ions (_bCa²⁺) levels as compared to control HUVECs, whereas, AscH2 treatment induced a slight upregulation of _bCa²⁺ levels in infected HUVECs as compared to infected and untreated HUVECs (p > 0.05). On the other hand, AscH2 treatment downregulated increased total cellular cholesterol content (_tccCHOL) levels in HUVECs induced by S. aureus infection (p < 0.05). In addition, AscH2 treatment markedly reversed S. aureus effect on upregulation of intracellular glucose (_iGLU) levels within infected HUVECs (p < 0.05). Moreover, AscH2 treatment significantly downregulated S. aureus growth (p < 0.05), and significantly upregulated bacterial internalization and intracellular killing by HUVECs (p < 0.05), as well as their cell cycle activation (p < 0.01). Finally, AscH2 treatment has a slight effect on the production of interleukin 6 (IL-6), but induced a marked downregulation of that of IL-1β in S. aureus-infected HUVECs (respectively, p > 0.05, and p < 0.05).

CONCLUSIONS

Our outcomes demonstrated that, during S. aureus infection, AscH2 treatment promotes human ECs survival and function, as well as prevents inflammatory response exacerbation, while inducing bactericidal activity.

Differential expression of serum GBP-28, NBP-Cyc 3 and TIMP-1 complicates pregnancy in hypertensive disorder pregnancy

The current study is aimed at analyzing the correlation and differential expression of three entities namely, TIMP metallopeptidase inhibitor-1 (TIMP-1), a glycoprotein, serum adipokine (GBP-28), an amino acid protein and neuroendocrine basic polypeptide NBP-cystatin3 (NBP-Cyc 3) in HDP (Hypertensive Disorders complicating Pregnancy). A total of 63 patients, diagnosed with HDP at the study hospital during the study period, was placed under treatment (HDP) group. While healthy group had a total of 50 women with normal pregnancy during the same period. Both these groups were compared in terms of GBP-28, TIMP-1 and NBP-Cyc 3 levels. Further, the author also checked the correlation, diagnostic value and prognosis for the three factors and HDP. There was a significant increase observed in the expression levels of serum TIMP-1 and NBP-Cyc 3 in HDP during ELISA compared to GB. However, HDP group recorded low value of serum GBP-28 than healthy group (all P < 0.001). There is a relationship between the expressions of GBP-28, TIMP-1 and NBP-Cyc 3 and the abnormalities in lipid and glucose metabolisms, resulting in severe clinical conditions among HDP patients. The inference from spearman correlation analysis is that serum GBP-28 and the severity of HDP are negatively correlated. While Serum TIMP-1 and NBP-Cyc 3 had a positive correlation with the severity of HDP (all P < 0.001). When diagnosing HDP, the AUC values of both GBP-28 and NBP-Cyc 3 single diagnosis were above 0.8. Multivariate conditional logistic regression was deployed to assess the risk factors associated with HDP. The results listed the independent risk factors such as GBP-28, TIMP-1 and NBP-Cyc 3 and disease severity for the prognosis of HDP. Among HDP patients, upregulated expressions of serum TIMP-1and NBP-Cyc 3 were observed while in case of GBP-28, it was vice versa. The significant role, played by GBP-28, TIMP-1 and NBP-Cyc 3 in the progression of HDP, makes these entities potential serum biomarkers in diagnosis and assessment of HDP.

Discovery and Structure-Activity Relationships of Novel Template, Truncated 1'-Homologated Adenosine Derivatives as Pure Dual PPARγ/δ Modulators

Following our report that A₃ adenosine receptor (AR) antagonist 1 exhibited a polypharmacological profile as a dual modulator of peroxisome proliferator-activated receptor (PPAR)γ/δ, we discovered a new template, 1'-homologated adenosine analogues 4a-4t, as dual PPARγ/δ modulators without AR binding. Removal of binding affinity to A₃AR was achieved by 1'-homologation, and PPARγ/δ dual modulation was derived from the structural similarity between the target nucleosides and PPAR modulator drug, rosiglitazone. All the final nucleosides were devoid of AR-binding affinity and exhibited high binding affinities to PPARγ/δ but lacked PPARα binding. 2-Cl derivatives exhibited dual receptor-binding affinity to PPARγ/δ, which was absent for the corresponding 2-H derivatives. 2-Propynyl substitution prevented PPARδ-binding affinity but preserved PPARγ affinity, indicating that the C2 position defines a pharmacophore for selective PPARγ ligand designs. PPARγ/δ dual modulators functioning as both PPARγ partial agonists and PPARδ antagonists promoted adiponectin production, suggesting their therapeutic potential against hypoadiponectinemia-associated cancer and metabolic diseases.

The Metabolic Rearrangements of Bariatric Surgery: Focus on Orexin-A and the Adiponectin System

The accumulation of adipose tissue represents one of the characteristics of obesity, increasing the risk of developing correlated obesity diseases such as cardiovascular disease, type 2 diabetes, cancer, and immune diseases. Visceral adipose tissue accumulation leads to chronic low inflammation inducing an imbalanced adipokine secretion. Among these adipokines, Adiponectin is an important metabolic and inflammatory mediator. It is also known that adipose tissue is influenced by Orexin-A levels, a neuropeptide produced in the lateral hypothalamus. Adiponectin and Orexin-A are strongly decreased in obesity and are associated with metabolic and inflammatory pathways. The aim of this review was to investigate the involvement of the autonomic nervous system focusing on Adiponectin and Orexin-A after bariatric surgery. After bariatric surgery, Adiponectin and Orexin-A levels are strongly increased independently of weight loss showing that hormone increases are also attributable to a rearrangement of metabolic and inflammatory mediators. The restriction of food intake and malabsorption are not sufficient to clarify the clinical effects of bariatric surgery suggesting the involvement of neuro-hormonal feedback loops and also of mediators such as Adiponectin and Orexin-A.

Brown adipose tissue transplantation as a novel alternative to obesity treatment: a systematic review

BACKGROUND

Obesity, a global challenge, is a complex disorder linked to various diseases. Different kinds of treatments are currently used to treat or control this pandemic. Despite their positive effects on controlling obesity, they still have limitations and side effects including digestive problems, difficulties of daily infusion of some drugs, surgical complications, and weight regain. All these issues cause these conventional methods not to have desirable efficacy. In this regard, brown adipose tissue (BAT) transplantation as a new investigational treatment is proposed, which has beneficial effects with no documented side effect in studies up to now.

METHODS

This systematic review protocol was registered in the International Prospective Register of Systematic Reviews (Registration Number: CRD42018110045). The systematical search was conducted on Web of Science, Scopus, PubMed, Embase, and ProQuest databases. The quality assessments in the included studies and data gathering were conducted independently by two authors. The main variables were anthropometric indices including body weight, levels of leptin, IGF-1, glucagon, adiponectin, fasting blood glucose, and UCP-1.

RESULTS

Following the search in mentioned databases, ten articles were entered into this systematic review. In most studies, weight gain and white adipocyte size were reduced in the BAT transplant group. It seems that the transplantation leads to the regeneration of healthy adipose tissue by activating the endogenous BAT.

CONCLUSIONS

Since BAT transplantation is one of the possible future treatments of obesity, many studies are conducted to evaluate the outcomes and related procedures precisely, so it can finally step into clinical application.

Long-term Impact of Mini-Gastric Bypass on Inflammatory Cytokines in Cohort of Morbidly Obese Patients: a Prospective Study

PURPOSE

One anastomosis gastric bypass (OAGB) is a promising bariatric procedure. We performed this study to evaluate the changes in a group of inflammatory cytokines 12 months after OAGB.

METHODS

A single-arm prospective study was conducted on obese patients who underwent OAGB. The serum levels of the following adipocytokines were monitored pre- and 12 months postoperatively: adiponectin, leptin, interleukin 6 (IL-6), interleukin 8 (IL-8) levels, tumor necrosis factor-alpha (TNF-α), serum amyloid A (SAA), high-sensitivity C-reactive protein (hs-CRP), and monocyte chemotactic protein 1 (MCP-1).

RESULTS

A total of 62 patients were included with a mean age of 43.9 ± 6.8 years old. The serum adiponectin increased significantly from 7.64 ± 0.29 to 8.76 ± 0.42 μg/mL 12 months after the operation (p < 0.001). hs-CRP and IL-6 decreased significantly 12 months after the OAGB from 3323.35 ± 643.4 ng/mL and 3.72 ± 7.7 pg/mL to 1376.81 ± 609.4 ng/mL and 3.64 ± 6.9 pg/mL, respectively (p < 0.001). The MCP-1 showed significant increase in its level after OAGB as well (p = 0.014). In contrary, there were no significant changes in serum levels of IL-8 (p = 0.12) and TNF-α (p = 0.84) 12 months after the operation. The correlation analysis showed significant correlations between initial body mass index (BMI) with serum adiponectin, IL-8, and serum SAA.

CONCLUSION

OAGB can significantly impact the inflammatory cytokine profile in obese patients with possible subsequent protection from obesity-related comorbidities such as insulin resistance, cardiovascular diseases, and certain cancers.

Serum Levels of Cystatin C, N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP), and Cardiac Function in Patients with Unstable Angina Pectoris

Background

This study aimed to investigate the association between serum levels of cystatin C, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and cardiac function in patients with unstable angina pectoris (UAP).

Material/Methods

A cross-sectional observational study was conducted at a single center and recruited 300 patients (214 men and 86 women), who were diagnosed with UAP between June 2018 to December 2018. The patients had serum levels of NT-ProBNP measured and were divided into four groups according to the serum levels of cystatin C: Q1, 0.49–0.83 mg/L; Q2, 0.84–1.04 mg/L; Q3, 1.05–1.38 mg/L; Q4, 1.39–4.21 mg/L. Cardiac function was graded according to the New York Heart Association (NYHA) class I to IV criteria.

Results

In the 300 patients with UAP, there were significant differences in cardiac function and NT-ProBNP levels between the four study groups (Q1 to Q4) (p<0.05). Univariate analysis showed that body weight, heart rate, treatment with aspirin, ticagrelor, angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker (ACE/ARB), diuretic use, uric acid level, and serum cystatin C levels were significantly associated with increased levels of NT-ProBNP. After adjusting for confounding factors screened in univariate analysis, multivariate regression analysis showed that increased serum cystatin C levels were significantly associated with increased levels of NT-ProBNP.

Conclusions

Increased serum levels of cystatin C were associated with poor cardiac function and increased levels of NT-ProBNP in patients with UAP.

Links Between Adiponectin and Dementia: From Risk Factors to Pathophysiology

With the aging population, dementia is becoming one of the most serious and troublesome global public health issues. Numerous studies have been seeking for effective strategies to delay or block its progression, but with little success. In recent years, adiponectin (APN) as one of the most abundant and multifunctional adipocytokines related to anti-inflammation, regulating glycogen metabolism and inhibiting insulin resistance (IR) and anti-atherosclerosis, has attracted widespread attention. In this article, we summarize recent studies that have contributed to a better understanding of the extent to which APN influences the risks of developing dementia as well as its pathophysiological progression. In addition, some controversial results interlinked with its effects on cognitive dysfunction diseases will be critically discussed. Ultimately, we aim to gain a novel insight into the pleiotropic effects of APN levels in circulation and suggest potential therapeutic target and future research strategies.

EPA and DHA elicit distinct transcriptional responses to high-fat feeding in skeletal muscle and liver

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) exert numerous beneficial biological effects and attenuate diet-induced insulin resistance in rodent models. In the present study, the independent, tissue-specific effects of two nutritionally relevant n-3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were characterized in the context of a high-fat diet (HFD). EPA and DHA supplementation (3.2% of total fat) in 6-mo-old male C57BL/6 mice fed an HFD (60% fat) partially mitigated reductions in insulin sensitivity. At 5 wk, the area above the curve below baseline glucose following an intraperitoneal insulin tolerance test was 54.5% lower in HFD than control, whereas HFD + EPA and HFD + DHA showed 27.6% and 17.1% reductions, respectively. At 10 wk, HFD increased mitochondrial oxidative capacity supported by lipid and carbohydrate-based substrates in both liver and skeletal muscle (P < 0.05), with little effect of EPA or DHA supplementation. Whole genome transcriptomic analyses revealed HFD-induced transcriptional changes indicative of inflammation and fibrosis in both liver and muscle. Gene set enrichment analyses indicated a downregulation of transcripts associated with extracellular matrix in muscle (family-wise error rate P < 0.01) and liver (P = 0.04) and in transcripts associated with inflammation in muscle (P = 0.03) in HFD + DHA compared with HFD alone. In contrast, EPA appeared to potentiate some proinflammatory effects of the HFD. In the skeletal muscle, DHA increased the expression of stress-responsive genes, whereas EPA upregulated the expression of transcripts related to cell cycle. Therefore, although both EPA and DHA supplementation during HFD partially preserve insulin signaling, they modulate distinct processes, highlighting their unique biological effects in the context of obesity.

Rosiglitazone-dependent dissociation of HuR from PPAR-γ regulates adiponectin expression at the posttranscriptional level

Peroxisome proliferator-activated receptor (PPAR)-γ has been implicated as a key player in the regulation of adiponectin levels via both transcriptional and posttranscriptional mechanisms. Herein, we show that PPAR-γ interacts with human antigen R (HuR) and that the PPAR-γ-HuR complex dissociates following activation of PPAR-γ by rosiglitazone, a specific ligand of PPAR-γ. This rosiglitazone-dependent dissociation of HuR from PPAR-γ leads to nucleocytoplasmic shuttling of HuR and its binding to the 3'-UTR of adiponectin mRNA. PPAR-γ with H321A and H447A double mutation (PPAR-γ^H321/447A), a mutant lacking ligand-binding activity, impaired HuR dissociation from the PPAR-γ-HuR complex, resulting in reduced nucleocytoplasmic shuttling, even in the presence of rosiglitazone. Consequently, rosiglitazone up-regulated adiponectin levels by modulating the stability of adiponectin mRNA, whereas these effects were abolished by HuR ablation or blocked in cells expressing the PPAR-γ^H321/447A mutant, indicating that the interaction of PPAR-γ and HuR is a critical event during adiponectin expression. Taken together, the findings demonstrate a novel mechanism for regulating adiponectin expression at the posttranscriptional level and suggest that ligand-mediated activation of PPAR-γ to interfere with interaction of HuR could offer a therapeutic strategy for inflammation-associated diseases that involve decreased adiponectin mRNA stability.-Hwang, J. S., Lee, W. J., Hur, J., Lee, H. G., Kim, E., Lee, G. H., Choi, M.-J., Lim, D.-S., Paek, K. S., Seo, H. G. Rosiglitazone-dependent dissociation of HuR from PPAR-γ regulates adiponectin expression at the posttranscriptional level.

Adiponectin-Secretion-Promoting Phenylethylchromones from the Agarwood of Aquilaria malaccensis

The therapeutic potential of adiponectin regulation has received interest because of its association with diverse human disease conditions, such as diabetes, obesity, atherosclerosis, and cancer. Phenylethylchromone derivatives from Aquilaria malaccensis-derived agarwood promoted adiponectin secretion during adipogenesis in human bone marrow mesenchymal stem cells, and 5,6-dihydroxy-2-(2-phenylethyl)chromone (1) was identified as a new chromone derivative. A target identification study with the most potent adiponectin-secretion-promoting phenylethylchromones, 6-methoxy-2-(2-phenylethyl)chromone (3) and 7-methoxy-2-(2-phenylethyl)chromone (4), showed that they are PPARγ partial agonists. Therefore, the diverse therapeutic effects of agarwood are associated with a PPARγ-mediated adiponectin-secretion-promoting mechanism.

Thymoquinone Potently Enhances the Activities of Classically Activated Macrophages Pulsed with Necrotic Jurkat Cell Lysates and the Production of Antitumor Th1-/M1-Related Cytokines

Antitumor activity of classically activated macrophage (Mϕ) may be impaired within the tumors, spleen, and bone marrow. Thus, it is possible to boost its antitumor activity after its pulsing with necrotic tumor cell lysates combined with an adjuvant. We set out to determine the potential adjuvant effects of thymoquinone (TQ; 2-isopropyl-5-methyl-1,4-benzoquinone, C₁₀H₁₂O₂) on both functional activities of classically activated Mϕs, pulsed or not with necrotic Jurkat T cell line lysates (NecrJCL), and the balance of antitumor cytokines (ATCs) versus immunosuppressive cytokines (ISCs) during crosstalk with autologous human CD4⁺ T cells. We found that TQ treatment resulted in a significant upregulation of phagocytic activity, respiratory burst, the production of interleukin-2 (IL-2), IL-6, and IL-17 in NecrJCL-pulsed Mϕ co-culture system, and, conversely, in downregulation of the production of IL-6, IL-17, nitric oxide (NO), and arginase activity in nonpulsed TQ-treated Mϕs co-culture system. In addition, TQ has also shown low upregulation effect on the production of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and IL-1β, pathogen killing capacity and H₂O₂ in NecrJCL-pulsed Mϕs co-cultures. Moreover, TQ significantly downregulated arginase activity, and significantly upregulated inducible NO synthase (iNOS) activity-to-arginase activity ratio in NecrJCL-pulsed Mϕ co-cultures. Furthermore, TQ downregulated IL-10-to-IL-17 ratio and total cellular cholesterol content (_ttcCHOL), but upregulated the ratios of IL-1β-to-IL-4, IL-1β-to-IL-10, IFN-γ-to-IL-4, IFN-γ-to-IL-10, TNF-α-to-IL-4, TNF-α-to-IL-10, and combined proinflammatory cytokines (PICs)-to-anti-inflammatory cytokines (AICs) in NecrJCL-pulsed Mϕs co-culture system, whereas significant differences were highlighted only for IL-10-to-IL-17, IFN-γ-to-IL-10, and PICs-to-AICs ratios. Our outcomes demonstrated that TQ can act as potent adjuvant for enhancing both the functional activities of NecrJCL-pulsed Mϕ and the production of ATCs during their interplay with CD4⁺ T cells.

Effects of canagliflozin versus glimepiride on adipokines and inflammatory biomarkers in type 2 diabetes

OBJECTIVE

Type 2 diabetes and obesity are pro-inflammatory states associated with increased risk of cardiovascular disease. Canagliflozin, an SGLT2 inhibitor, demonstrated superiority in lowering HbA1c versus glimepiride with less hypoglycemia and greater weight reduction via loss of fat mass in a 52-week trial of type 2 diabetes patients. This post hoc, exploratory analysis assessed the effects of canagliflozin versus glimepiride on select adipokines, inflammatory biomarkers, and chemokines.

METHODS

Changes from baseline to Week 52 in serum leptin, adiponectin, IL-6, TNFα, CRP, PAI-1, VCAM-1, and MCP-1 were measured in a randomly selected subset of type 2 diabetes patients on metformin receiving canagliflozin 300 mg (n = 100) or glimepiride (n = 100) in the overall study. Correlations between change in biomarkers and change in select metabolic and anthropometric variables were assessed.

RESULTS

At Week 52, canagliflozin decreased median serum leptin by 25% (95% CI: -34%, -15%) and increased median serum adiponectin by 17% (95% CI: 11%, 23%) compared with glimepiride. There was a 22% reduction in median serum IL-6 (95% CI: -34%, -10%) and a 7% increase in median serum TNFα (95% CI: 1%, 12%) with canagliflozin versus glimepiride. No between-group differences were observed with the other biomarkers. The decrease in serum leptin with canagliflozin was correlated with change in weight (r ≥ 0.3) only; the increase in adiponectin and decrease in IL-6 with canagliflozin occurred independently of changes in HbA1c, weight, or lipids.

CONCLUSIONS

These results indicate that canagliflozin may improve adipose tissue function and induce changes in serum leptin, adiponectin, and IL-6 that favorably impact insulin sensitivity and cardiovascular disease risk.

Modulation of Vascular Reactivity by Perivascular Adipose Tissue (PVAT)

PURPOSE OF REVIEW

In this review, we discuss the role of perivascular adipose tissue (PVAT) in the modulation of vascular contractility and arterial pressure, focusing on the role of the renin-angiotensin-aldosterone system and oxidative stress/inflammation.

RECENT FINDINGS

PVAT possesses a relevant endocrine-paracrine activity, which may be altered in several pathophysiological and clinical conditions. During the last two decades, it has been shown that PVAT may modulate vascular reactivity. It has also been previously demonstrated that inflammation in adipose tissue may be implicated in vascular dysfunction. In particular, adipocytes secrete a number of adipokines with various functions, as well as several vasoactive factors, together with components of the renin-angiotensin system which may act at local or at systemic level. It has been shown that the anti-contractile effect of PVAT is lost in obesity, probably as a consequence of the development of adipocyte hypertrophy, inflammation, and oxidative stress. Adipose tissue dysfunction is interrelated with inflammation and oxidative stress, thus contributing to endothelial dysfunction observed in several pathological and clinical conditions such as obesity and hypertension. Decreased local adiponectin level, macrophage recruitment and infiltration, and activation of renin-angiotensin-aldosterone system could play an important role in this regard.

Insulin Receptor Substrate 2 Controls Insulin-Mediated Vasoreactivity and Perivascular Adipose Tissue Function in Muscle

Introduction: Insulin signaling in adipose tissue has been shown to regulate insulin's effects in muscle. In muscle, perivascular adipose tissue (PVAT) and vascular insulin signaling regulate muscle perfusion. Insulin receptor substrate (IRS) 2 has been shown to control adipose tissue function and glucose metabolism, and here we tested the hypothesis that IRS2 mediates insulin's actions on the vessel wall as well as the vasoactive properties of PVAT.

Methods: We studied PVAT and muscle resistance arteries (RA) from littermate IRS2^+/+ and IRS2^−/− mice and vasoreactivity by pressure myography, vascular insulin signaling, adipokine expression, and release and PVAT morphology. As insulin induced constriction of IRS2^+/+ RA in our mouse model, we also exposed RA's of C57/Bl6 mice to PVAT from IRS2^+/+ and IRS2^−/− littermates to evaluate vasodilator properties of PVAT.

Results: IRS2^−/− RA exhibited normal vasomotor function, yet a decreased maximal diameter compared to IRS2^+/+ RA. IRS2^+/+ vessels unexpectedly constricted endothelin-dependently in response to insulin, and this effect was absent in IRS2^−/− RA due to reduced ERK1/2activation. For evaluation of PVAT function, we also used C57/Bl6 vessels with a neutral basal effect of insulin. In these experiments insulin (10.0 nM) increased diameter in the presence of IRS2^+/+ PVAT (17 ± 4.8, p = 0.014), yet induced a 10 ± 7.6% decrease in diameter in the presence of IRS2^−/− PVAT. Adipocytes in IRS2^−/− PVAT (1314 ± 161 μm²) were larger (p = 0.0013) than of IRS2^+/+ PVAT (915 ± 63 μm²). Adiponectin, IL-6, PAI-1 secretion were similar between IRS2^+/+ and IRS2^−/− PVAT, as were expression of pro-inflammatory genes (TNF-α, CCL2) and adipokines (adiponectin, leptin, endothelin-1). Insulin-induced AKT phosphorylation in RA was similar in the presence of IRS2^−/− and IRS2^+/+ PVAT.

Conclusion: In muscle, IRS2 regulates both insulin's vasoconstrictor effects, mediating ERK1/2-ET-1 activation, and its vasodilator effects, by mediating the vasodilator effect of PVAT. The regulatory role of IRS2 in PVAT is independent from adiponectin secretion.

Endothelium-specific CYP2J2 overexpression attenuates age-related insulin resistance

Ample evidences demonstrate that cytochrome P450 epoxygenase‐derived epoxyeicosatrienoic acids (EETs) exert diverse biological activities, which include potent vasodilatory, anti‐inflammatory, and cardiovascular protective effects. In this study, we investigated the effects of endothelium‐specific CYP2J2 overexpression on age‐related insulin resistance and metabolic dysfunction. Endothelium‐specific targeting of the human CYP epoxygenase, CYP2J2, transgenic mice (Tie2‐CYP2J2‐Tr mice) was utilized. The effects of endothelium‐specific CYP2J2 overexpression on aging‐associated obesity, inflammation, and peripheral insulin resistance were evaluated by assessing metabolic parameters in young (3 months old) and aged (16 months old) adult male Tie2‐CYP2J2‐Tr mice. Decreased insulin sensitivity and attenuated insulin signaling in aged skeletal muscle, adipose tissue, and liver were observed in aged adult male mice, and moreover, these effects were partly inhibited in 16‐month‐old CYP2J2‐Tr mice. In addition, CYP2J2 overexpression‐mediated insulin sensitization in aged mice was associated with the amelioration of inflammatory state. Notably, the aging‐associated increases in fat mass and adipocyte size were only observed in 16‐month‐old wild‐type mice, and CYP2J2 overexpression markedly prevented the increase in fat mass and adipocyte size in aged Tie2‐CYP2J2‐Tr mice, which was associated with increased energy expenditure and decreased lipogenic genes expression. Furthermore, these antiaging phenotypes of Tie2‐CYP2J2‐Tr mice were also associated with increased muscle blood flow, enhanced active‐phase locomotor activity, and improved mitochondrial dysfunction in skeletal muscle. Collectively, our findings indicated that endothelium‐specific CYP2J2 overexpression alleviated age‐related insulin resistance and metabolic dysfunction, which highlighted CYP epoxygenase‐EET system as a potential target for combating aging‐related metabolic disorders.

Relationship among adiponectin, insulin resistance and atherosclerosis in non-diabetic hypertensive patients and healthy adults

Adiponectin, which is secreted specifically by adipose tissue, has been shown to have anti-atherogenic and anti-inflammatory effects and to improve insulin resistance (IR). The aim of this study was to determine the correlations among adiponectin, IR and atherosclerosis in non-diabetic hypertensive patients and healthy volunteers. In this case control study, we collected complete demographic data from and measured several laboratory parameters in all enrolled subjects. The homeostasis model of assessment for insulin resistance (HOMA-IR) was calculated as an insulin sensitivity index. The atherogenic index of plasma (AIP), which is calculated as log (triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C)), was a significant predictor of atherosclerosis and was a better predictor of atherosclerosis than low-density lipoprotein cholesterol (LDL-C). Plasma adiponectin, interleukin (IL)-6, monocyte chemoattractant protein-1 (MCP-1) and matrix metalloprotein-9 (MMP-9) concentrations were determined using enzyme-linked immunosorbent assay (ELISA). All data were analyzed using Statistical Product and Service Solutions for Windows (SPSS) 13.0 software. A total of 309 participants were enrolled in the study. Hypertensive patients with IR (n = 93) displayed significantly higher HOMA-IR values and AIPs and lower adiponectin levels than hypertensive patients without IR (n = 121) and healthy adults (n = 95) (P < 0.05). Furthermore, circulating IL-6, MCP-1 and MMP-9 concentrations differed significantly between hypertensive patients and healthy adults (P < 0.05). Additionally, adiponectin levels were found to be inversely correlated with IL-6, MCP-1, and MMP-9 levels; HOMA-IR values; and AIPs in the clinical study. HOMA-IR values and adiponectin and creatinine (Cr) concentrations remained independently associated with AIPs in all participants after adjustment for confounders via multivariate linear regression. Low adiponectin levels are positively correlated with decreased insulin sensitivity, increased pro-inflammatory cytokine production and worsening atherosclerosis in hypertensive patients and healthy adults.

Increased adipose tissue aromatase activity improves insulin sensitivity and reduces adipose tissue inflammation in male mice

Females are, in general, more insulin sensitive than males. To investigate whether this is a direct effect of sex-steroids (SS) in white adipose tissue (WAT), we developed a male mouse model overexpressing the aromatase enzyme, converting testosterone (T) to estradiol (E₂), specifically in WAT (Ap2-arom mice). Adipose tissue E₂ levels were increased while circulating SS levels were unaffected in male Ap2-arom mice. Importantly, male Ap2-arom mice were more insulin sensitive compared with WT mice and exhibited increased serum adiponectin levels and upregulated expression of Glut4 and Irs1 in WAT. The expression of markers of macrophages and immune cell infiltration was markedly decreased in WAT of male Ap2-arom mice. The adipogenesis was enhanced in male Ap2-arom mice, supported by elevated Pparg expression in WAT and enhanced differentiation of preadipocyte into mature adipocytes. In summary, increased adipose tissue aromatase activity reduces adipose tissue inflammation and improves insulin sensitivity in male mice. We propose that estrogen increases insulin sensitivity via a local effect in WAT on adiponectin expression, adipose tissue inflammation, and adipogenesis.

Effect of adiponectin on macrophage reverse cholesterol transport in adiponectin-/- mice and its mechanism

The objective of the present study was to investigate the effect of adiponectin (APN) on macrophage reverse cholesterol transport (RCT) in adiponectin-/- knockout mice (APN-/-mice) and its possible anti-atherosclerotic mechanism. A total of 30 male APN-/-mice were randomly divided into the control group and four intervention groups. The intervention groups were treated with intraperitoneal injections of APN, at doses of 50, 150, 200 and 250 µg/(kg/day), respectively, for 4 weeks. The control group received normal saline. After 4 weeks, serum lipid levels were measured, the degree of severity of atherosclerotic lesions was observed by light microscopy, the ³H-TC (APN-/-mice treated with intraperitoneal injections of ³H-TC-labeled macrophages) radioactivity in serum, liver, and feces, and the expression of ABCA1 mRNA and protein in liver were determined. Compared with the control group, serum triglycerides, total cholesterol, and low-density lipoproteins levels in the intervention groups were significantly decreased, while high-density lipoprotein was increased. The severity of aortic atherosclerotic lesions in the intervention groups was milder than in the control group, which had obvious aortic atherosclerotic lesions, large lipid deposition on vessel walls, and the formation of atheromatous plaques. In the intervention groups, serum ³H-TC content was significantly decreased (P<0.05), but the ³H-TC content in liver and feces was significantly increased (P<0.05). The levels of ABCA1 mRNA in liver of the intervention groups were significantly increased in a dose-dependent manner. In conclusion, APN can promote RCT and intracellular cholesterol efflux by upregulating the expression of ABCA1, to delay the occurrence and development of atherosclerosis.

Adipo/cytokines in atherosclerotic secretomes: increased visfatin levels in unstable carotid plaque

Background

Novel pro-inflammatory and anti-inflammatory derivatives from adipose tissue, known as adipokines, act as metabolic factors. The aim of this study was to analyse the secreted expression of different adipo/cytokines in secretomes of unstable carotid atherosclerotic plaque versus non-atherosclerotic mammary artery.

Methods

We evaluated the secretion levels of adiponectin, visfatin, lipocalin-2, resistin, IL-6 and TNFR2 by ELISA in human secretomes from cultured unstable carotid atherosclerotic plaque (n = 18) and non-atherosclerotic mammary artery (n = 13). We also measured visfatin serum levels in patients suffering from atherosclerosis and in a serum cohort of healthy subjects (n = 16).

Results

We found that visfatin levels were significantly increased in unstable carotid atherosclerotic plaque secretome than in non-atherosclerotic mammary artery secretome. No differences were found with regard the other adipo/cytokines studied. Regarding visfatin circulating levels, there were no differences between unstable carotid atherosclerotic plaque and non-atherosclerotic mammary artery group. However, these visfatin levels were increased in comparison to serum cohort of healthy subjects.

Conclusions

Of all the adipo/cytokines analysed, only visfatin showed increased levels in secretomes of unstable carotid atherosclerotic plaque. Additional human studies are needed to clarify the possible role of visfatin as prognostic factor of unstable carotid atherosclerotic plaque.

Alleviation of high-fat diet-induced atherosclerosis and glucose intolerance by a novel GLP-1 fusion protein in ApoE(-/-) mice

We have previously constructed an engineered anti-diabetic fusion protein using glucagon-like peptide-1 and the globular domain of adiponectin. Herein, we evaluated the therapeutic effects of this fusion protein (GAD) on high-fat diet (HFD)-fed ApoE(-/-) mice. The lipid-lowering effect of GAD was determined in C57BL/6 mice using a lipid tolerance test. The effects of GAD on HFD-induced glucose intolerance, atherosclerosis, and hepatic steatosis were evaluated in HFD-fed ApoE(-/-) mice using glucose tolerance test, histological examinations and real-time quantitative PCR. The anti-inflammation activity of GAD was assessed in vitro on macrophages. GAD improved lipid metabolism in C57BL/6 mice. GAD treatment alleviated glucose intolerance, reduced blood lipid level, and attenuated atherosclerotic lesion in HFD-fed ApoE(-/-) mice, which was associated with a repressed macrophage infiltration in the vessel wall. GAD treatment also blocked hepatic macrophage infiltration and prevented hepatic inflammation. GAD suppressed lipopolysaccharide-triggered inflammation responses on macrophages, which can be abolished by H89, an inhibitor of protein kinase A. These findings demonstrate that GAD is able to generate a variety of metabolic benefits in HFD-fed ApoE(-/-) mice and indicate that this engineered fusion protein is a promising lead structure for anti-atherosclerosis drug discovery.

Regulation of cytokine gene expression by orosomucoid in neonatal swine adipose tissue

Background

Porcine adipose tissue expresses orosomucoid (ORM1) mRNA, a protein with anti-inflammatory and immunomodulatory properties. Previous research has demonstrated that porcine ORM1 can reduce insulin stimulated glucose metabolism in porcine adipose tissue in vitro. The present study was designed to examine the preweaning ontogeny of ORM1 mRNA abundance in porcine subcutaneous adipose and to determine if ORM1 can regulate mRNA abundance of inflammatory cytokines that contribute to insulin resistance in primary cultures derived from neonatal porcine subcutaneous adipose tissue. Cultures were differentiated in vitro and subsequently the adipocyte containing cultures were incubated for 24 h with 0–5000 ng porcine ORM1/mL medium. Cultures were then harvested, total RNA extracted for use in reverse transcription and the mRNA abundance of cytokine mRNA quantified by real-time PCR.

Results

ORM1 mRNA abundance within neonatal adipose tissue does not change from d 1 to d 21 of age and is a very small fraction relative to liver mRNA abundance. The ORM1 mRNA level in porcine adipocytes and stromal-vascular cells are similar (P > 0.05). Treatment with ORM1 did not affect TNFα (tumor necrosis factor α) mRNA level (P > 0.05), while interleukin 6 (IL6) mRNA abundance was reduced 32 % at 1,000 ng ORM1/mL (P < 0.01). However, TNFα protein content in the cell culture media was reduced by ORM1 treatment (5,000 ng/mL, P < 0.05), whereas ORM1 had no detectable effect on the media content of IL6 (P > 0.05). The reduction of macrophage migration inhibitory factor (MIF) mRNA abundance by ORM1 was dose dependent (P < 0.01). Monocyte chemotactic protein (MCP) mRNA level was reduced 27 % by 1,000 ng ORM1/mL (P < 0.05).

Conclusions

The data suggest that ORM1 has limited effects TNFα, IL6, MIF or MCP expression at the concentrations tested. Secondly, these cytokines do not appear to contribute to the reported insulin resistance induced by ORM1 in porcine adipose tissue in vitro as an increase in the abundance of these inflammatory cytokines would be predicted during an insulin resistant state.

Adiponectin: a versatile player of innate immunity

Adiponectin acts as a key regulator of the innate immune system and plays a major role in the progression of inflammation and metabolic disorders. Macrophages and monocytes are representative components of the innate immune system, and their proliferation, plasticity, and polarization are a key component of metabolic adaption. Innate-like lymphocytes such as group 2 innate lymphoid cells (ILC2s), natural killer T (NKT) cells, and gamma delta T (γδ T) cells are also members of the innate immune system and play important roles in the development of obesity and its related diseases. Adiponectin senses metabolic stress and modulates metabolic adaption by targeting the innate immune system under physiological and pathological conditions. Defining the mechanisms underlying the role of adiponectin in regulating innate immunity is crucial to adiponectin-based therapeutic intervention.

Role of bioactive lipid mediators in obese adipose tissue inflammation and endocrine dysfunction

White adipose tissue is recognized as an active endocrine organ implicated in the maintenance of metabolic homeostasis. However, adipose tissue function, which has a crucial role in the development of obesity-related comorbidities including insulin resistance and non-alcoholic fatty liver disease, is dysregulated in obese individuals. This review explores the physiological functions and molecular actions of bioactive lipids biosynthesized in adipose tissue including sphingolipids and phospholipids, and in particular fatty acids derived from phospholipids of the cell membrane. Special emphasis is given to polyunsaturated fatty acids of the omega-6 and omega-3 families and their conversion to bioactive lipid mediators through the cyclooxygenase and lipoxygenase pathways. The participation of omega-3-derived lipid autacoids in the resolution of adipose tissue inflammation and in the prevention of obesity-associated hepatic complications is also thoroughly discussed.

Ghrelin receptor regulates adipose tissue inflammation in aging

Aging is commonly associated with low-grade adipose inflammation, which is closely linked to insulin resistance. Ghrelin is the only circulating orexigenic hormone which is known to increase obesity and insulin resistance. We previously reported that the expression of the ghrelin receptor, growth hormone secretagogue receptor (GHS-R), increases in adipose tissues during aging, and old Ghsr(-/-) mice exhibit a lean and insulin-sensitive phenotype. Macrophages are major mediators of adipose tissue inflammation, which consist of pro-inflammatory M1 and anti-inflammatory M2 subtypes. Here, we show that in aged mice, GHS-R ablation promotes macrophage phenotypical shift toward anti-inflammatory M2. Old Ghsrp(-/-) mice have reduced macrophage infiltration, M1/M2 ratio, and pro-inflammatory cytokine expression in white and brown adipose tissues. We also found that peritoneal macrophages of old Ghsrp(-/-) mice produce higher norepinephrine, which is in line with increased alternatively-activated M2 macrophages. Our data further reveal that GHS-R has cell-autonomous effects in macrophages, and GHS-R antagonist suppresses lipopolysaccharide (LPS)-induced inflammatory responses in macrophages. Collectively, our studies demonstrate that ghrelin signaling has an important role in macrophage polarization and adipose tissue inflammation during aging. GHS-R antagonists may serve as a novel and effective therapeutic option for age-associated adipose tissue inflammation and insulin resistance.

Dietary Omega-3 Fatty Acid Supplementation Reduces Inflammation in Obese Pregnant Women: A Randomized Double-Blind Controlled Clinical Trial

Objective

Long-chain omega 3 fatty acids, eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) exert potent anti-inflammatory properties in humans. This study characterized the effects of omega-3 ω-3 fatty acids supplements (ω-3 FA) on the inflammatory status in the placenta and adipose tissue of overweight/obese pregnant women.

Study Design

A randomized, double-masked controlled trial was conducted in overweight/obese pregnant women that were randomly assigned to receive DHA plus EPA (2g/day) or the equivalent of a placebo twice a day from week 10–16 to term. Inflammatory pathways were characterized in: 1) adipose tissue and placenta of treated vs. untreated women; and 2) adipose and trophoblast cells cultured with long chain FAs.

Results

The sum of plasma DHA and EPA increased by 5.8 fold and ω-3 FA/ ω-6 FA ratio was 1.5 in treated vs. untreated women (p< 0.005). Plasma CRP concentrations were reduced (p<0.001). The adipose tissue and placenta of treated women exhibited a significant decrease in TLR4 adipose and placental expression as well as IL6, IL8, and TNFα In vitro, EPA and DHA suppressed the activation of TLR4, IL6, IL8 induced by palmitate in culture of adipose and trophoblast cells.

Conclusion

Supplementation of overweight/obese pregnant women with dietary ω-3 FAs for >25 weeks reduced inflammation in maternal adipose and the placental tissue. TLR4 appears as a central target of the anti-inflammatory effects at the cellular level.

Trial Registration

ClinicalTrials.gov NCT00957476

Association of adiponectin gene polymorphisms with an elevated risk of diabetic peripheral neuropathy in type 2 diabetes patients

OBJECTIVE

In this study, we examined the association between two adiponectin (ADPN) gene polymorphisms, +45T/G and +276G/T, and susceptibility to diabetic peripheral neuropathy (DPN) in type 2 diabetes mellitus (T2DM) patients.

METHODS

A total of 180 T2DM patients were enrolled in this study and assigned to two groups: DPN group (n=90) and non-DPN (NDPN) group (n=90). In addition, 90 healthy subjects were chosen as healthy normal control (NC). The plasma level of ADPN was quantified by ELISA method and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for genotype analysis of the two ADPN polymorphisms, +45T/G (rs2241766) and +276G/T (rs1501299), in all the study subjects. Statistical analysis of data was performed with SPSS version 20.0 software.

RESULTS

Serum levels of ADPN were markedly reduced in the DPN group compared to NDPN and NC groups (all P<0.05). The frequencies of TT, TG and GG genotypes and the T and G alleles of T45G and G276T polymorphisms in DPN group were significantly different than the NDPN group (all P<0.05). Notably, T45G and G276T polymorphisms were associated with significantly reduced plasma levels of ADPN in DPN and NDPN groups, compared to the NC group (P<0.001). Significant difference in ADPN plasma levels were also observed between TT, TG and GG genotypes of T45G and G276T polymorphisms. Our results indicate that the T allele in +45T/G and +276G/T polymorphisms is correlated with an elevated risk of DPN in T2DM patients. Haplotype analysis showed that GG and GT haplotypes showed a negative relationship with DPN, while TG haplotype positively correlated with risk of DPN in T2DM patients (all P<0.05).

CONCLUSION

Our results show that T45G and G276T polymorphisms of ADPN are associated with a significantly elevated risk of DPN in T2DM patients, likely by down-regulating ADPN serum level.

Adiponectin regulates psoriasiform skin inflammation by suppressing IL-17 production from γδ-T cells

Accumulating epidemiologic evidence has revealed that metabolic syndrome is an independent risk factor for psoriasis development and is associated with more severe psoriasis. Adiponectin, primarily recognized as a metabolic mediator of insulin sensitivity, has been newly drawing attention as a mediator of immune responses. Here we demonstrate that adiponectin regulates skin inflammation, especially IL-17-related psoriasiform dermatitis. Mice with adiponectin deficiency show severe psoriasiform skin inflammation with enhanced infiltration of IL-17-producing dermal Vγ4+γδ-T cells. Adiponectin directly acts on murine dermal γδ-T cells to suppress IL-17 synthesis via AdipoR1. We furthermore demonstrate here that the adiponectin level of skin tissue as well as subcutaneous fat is decreased in psoriasis patients. IL-17 production from human CD4- or CD8-positive T cells is also suppressed by adiponectin. Our data provide a regulatory role of adiponectin in skin inflammation, which would imply a mechanism underlying the relationship between psoriasis and metabolic disorders.

The amount of C1q-adiponectin complex is higher in the serum and the complex localizes to perivascular areas of fat tissues and the intimal-medial layer of blood vessels of coronary artery disease patients

Background

The complement component C1q triggers activation of the classical immune pathway and can bind to adiponectin (APN). Recently, some studies have been reported that serum C1q-APN/total APN ratio correlates with atherosclerosis and coronary artery disease (CAD). We assessed the relationships between C1q related variables and the severity of CAD, and investigated the localization of the C1q–APN complex.

Methods

The sample included 153 subjects comprising healthy controls and patients with subclinical or overt CAD. We measured the serum concentrations of C1q, total APN, and high-molecular weight (HMW)-APN, and the amount of C1q–APN complex. We identified the sites of C1q–APN complex deposition in various adipose tissues and blood vessels.

Results

Serum concentrations of C1q and HMW-APN and the C1q/HMW-APN ratio were independently associated with the severity of coronary stenosis. The amount of C1q–APN complex was significantly higher in patients with CAD compared with controls. C1q and APN co-localized in perivascular areas of subcutaneous, visceral, and pericardial fat tissues, and the internal mammary artery of patients with severe CAD.

Conclusions

Serum C1q concentration and the C1q/HMW-APN ratio were independent markers of coronary artery stenosis. The amount of C1q–APN complex was significantly greater in serum from CAD patients. C1q and APN co-localized to perivascular areas in adipose tissue and blood vessels. The association between the increased amount of the C1q–APN complex and CAD should be investigated further.