Effect of Leptin on Chronic Inflammatory Disorders: Insights to Therapeutic Target to Prevent Further Cardiovascular Complication

A Simplified and Robust Model for the Study of Diabetic Nephropathy: Streptozotocin-Induced Diabetic Mice Fed a High-Protein Diet

To better understand diabetic nephropathy (DN), developing accurate animal models is crucial. Current models often fail to fully mimic human DN, showing only mild albuminuria, glomerular hypertrophy, and limited mesangial matrix expansion. Our study aims to develop a more robust model by combining streptozotocin (STZ)-induced diabetes with a high-protein diet (HPD). We divided C57Bl/6J mice into three groups: control, STZ with a standard diet (STZ-SD), and STZ with a HPD (45 kcal% protein) (STZ-HPD) for 12 weeks. Renal function was evaluated using the urinary albumin-to-creatinine ratio, and kidney tissues were analyzed for histological and molecular changes. The STZ-HPD group showed significantly higher albuminuria and more severe glomerular and tubular damage compared to the control and STZ-SD groups. These changes were accompanied by increased inflammatory and oxidative stress markers, highlighting the harmful effects of high-protein intake on renal injury. Our findings suggest that the STZ-HPD model could be a valuable tool for studying DN pathophysiology and evaluating therapeutic interventions, providing a new approach for preclinical research.

Frozen Shoulder as a Metabolic and Immune Disorder: Potential Roles of Leptin Resistance, JAK-STAT Dysregulation, and Fibrosis

Frozen shoulder (FS) is a complex and multifactorial condition characterized by persistent inflammation, fibrosis, and metabolic dysregulation. Despite extensive research, the underlying drivers of FS remain poorly understood. Recent findings indicate the coexistence of pro-inflammatory and fibrosis-resolving macrophages within affected tissues, suggesting a dysregulated immune response influenced by metabolic and neuroendocrine factors. This review proposes that leptin resistance, a hallmark of metabolic syndrome and chronic inflammation, may play a central role in FS pathogenesis by impairing macrophage polarization, perpetuating inflammation, and disrupting fibrosis resolution. The JAK-STAT signaling pathway, critically modulated by leptin resistance, may further contribute to immune dysregulation by sustaining inflammatory macrophage activation and interfering with tissue remodeling. Additionally, FS shares pathogenic features with fibrotic diseases driven by TGF-β signaling, mitochondrial dysfunction, and circadian disruption, further linking systemic metabolic dysfunction to localized fibrotic pathology. Beyond immune and metabolic regulation, alterations in gut microbiota, bacterial translocation, and chronic psychosocial stress may further exacerbate systemic inflammation and neuroendocrine imbalances, intensifying JAK-STAT dysregulation and leptin resistance. By examining the intricate interplay between metabolism, immune function, and fibrotic remodeling, this review highlights targeting leptin sensitivity, JAK-STAT modulation, and mitochondrial restoration as novel therapeutic strategies for FS treatment. Future research should explore these interconnections to develop integrative interventions that address both the metabolic and immune dysregulation underlying FS, ultimately improving clinical outcomes.

Inflammation-Related Markers in Pediatric Psoriasis: Resistin as a Potential Marker of Psoriasis Severity

Background/Objective: Psoriasis is a chronic inflammatory skin disease. Studies on adult population have confirmed that there is an association between psoriasis and metabolic as well as cardiovascular diseases. The aim of this study was to evaluate the inflammatory potential and the association of psoriasis with metabolic and cardiovascular risk by analyzing serum concentrations of homocysteine, adiponectin, resistin, leptin, and pentraxin 3 in pediatric patients with psoriasis. Additionally, the study explored correlations between these biomarkers and psoriasis severity. Methods: The study included 75 pediatric patients (47 girls and 28 boys) aged 2-17 years with clinically confirmed psoriasis. In addition, 28 healthy children (15 girls and 13 boys) without psoriasis, metabolic or inflammatory diseases made up the control group. Psoriasis severity was evaluated using the scales psoriasis area and severity index (PASI) and the body surface area (BSA). Serum concentrations of homocysteine, adiponectin, pentraxin 3, resistin, and leptin were measured in both groups. Results: Children with psoriasis exhibited higher serum levels of homocysteine, resistin, leptin, and pentraxin 3 and lower serum levels of adiponectin compared to the control group. A positive correlation was observed between resistin serum concentration and psoriasis severity. Elevated resistin levels were associated with higher PASI and BSA scores. Conclusions: Psoriasis is an inflammatory disease that is potentially linked to metabolic disorders. Resistin may serve as a biomarker for psoriasis severity; however, this relationship requires further research.

Exploring Anti-Inflammatory Treatment as Upstream Therapy in the Management of Atrial Fibrillation

Inflammation has been widely recognized as one of the major pathophysiological drivers of the development of atrial fibrillation (AF), which works in tandem with other risk factors of AF including obesity, diabetes, hypertension, and heart failure (HF). Our current understanding of the role of inflammation in the natural history of AF remains elusive; however, several key players, including the NLRP3 (NLR family pyrin domain containing 3) inflammasome, have been acknowledged to be heavily influential on chronic inflammation in the atrial myocardium, which leads to fibrosis and eventual degradation of its electrical function. Nevertheless, our current methods of pharmacological modalities with reported immunomodulatory properties, including well-established classes of drugs e.g., drugs targeting the renin-angiotensin-aldosterone system (RAAS), statins, and vitamin D, have proven effective in reducing the overall risk of developing AF, the onset of postoperative atrial fibrillation (POAF), and reducing overall mortality among patients with AF. This might bring hope for further progress in developing new treatment modalities targeting cellular checkpoints of the NLRP3 inflammasome pathway, or revisiting other well-known anti-inflammatory drugs e.g., colchicine, vitamin C, nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticosteroids, and antimalarial drugs. In our review, we aim to find relevant upstream anti-inflammatory treatment methods for the management of AF and present the most current real-world evidence of their clinical utility.

Epigenetic programming of obesity in early life through modulation of the kynurenine pathway

Childhood obesity is a global health concern that has its origins before birth. Although genetics plays a crucial role, increasing evidence suggests that epigenetic modifications during fetal life could also influence its incidence. In this model, during the fetal period, interactions between genetic makeup, intrauterine factors, and environmental conditions, increase the risk of childhood obesity. This is in accordance with the Developmental Origins of Health and Disease (DOHaD) hypothesis, in which specific intrauterine environments can have long-lasting effects on the immune system's essential functions during crucial stages of fetal growth, resulting in permanent changes to the immune function of the offspring. Consequently, dysfunction can consequently make the offspring more prone to inflammatory and immune-related disorders later in life. In this review, we examine how maternal inflammation could influence the risk of childhood obesity. We propose that during pregnancy, modification of the expression of critical genes in metabolic and signaling pathways, such as the kynurenine (Kyn) pathway, occurs due to increased levels of maternal inflammation. We also propose that such expression differences are mediated by epigenetic changes. Furthermore, we also hypothesize that the Kyn pathway produces metabolites that have immunoregulatory effects and may play a crucial role in regulating inflammation during pregnancy. As a result, interventions aimed at improving maternal inflammation may be able to help alleviate the risk of childhood obesity.

A systematic review and meta-analysis investigating differences in chronic inflammation and adiposity before and after menopause

BACKGROUND

Menopause represents a pivotal physiological transition characterized by hormonal fluctuations and an augmented susceptibility to chronic diseases. The relationship between menopause and heightened disease risk may be attributed in part to alterations in low-grade chronic inflammation and adiposity.

METHODS

Three databases were searched for studies assessing differences in inflammation and body adiposity between pre- and postmenopausal women. Meta-analysis examined the association between menopausal status and key inflammatory biomarkers, including leptin, adiponectin, interleukin-6, tumour necrosis factor-α and c-reactive protein, and indices of body adiposity (fat mass, waist circumference, waist-to-hip-ratio and body mass index). The National Institute of Health Quality Assessment Tool for Observational and Cross-sectional studies was used to evaluate quality of studies, and GRADE-assessed evidence certainty.

RESULTS

Levels of adiponectin and leptin were higher in postmenopausal women than in premenopausal women [(1.30 μg/ml, 95 % CI; 0.56 to 2.03 μg/ml, p = 0.001), (0.88 ng/ml; 95 % CI: 0.22 to 1.52; p = 0.008)]. A trend towards significance was observed for tumour necrosis factor-α (0.59 pg/ml, 95 % CI; -0.07 to 1.26 pg/ml, p = 0.080), with no significant differences in interleukin-6 and c-reactive protein [(0.83 pg/ml, 95 % CI; -0.24 to 1.91 pg/ml, p = 0.128), (0.06 mg/ml, 95 % CI; -0.17 to 0.29, p = 0.606)]. Postmenopausal women had greater waist circumference, waist-to-hip-ratio and body mass index than premenopausal women [(0.74 cm; 95 % CI: 1.02 to 0.47; p ≤0.001), (0.78; 95 % CI: 1.47 to -0.09; p = 0.027), (0.31 kg/m2; 95 % CI: 0.50 to 0.12; p = 0.001)].

CONCLUSIONS

Postmenopausal women had higher adipokine levels and greater adiposity. However, given the low certainty of the available evidence, future prospective cohort studies assessing inflammatory changes over the menopausal transition are warranted to inform future clinical decisions. Protocol registered on the Open Science Framework (OSF-ID: 10.17605/OSF.IO/DY8T6).

The Role of Adipokines between Genders in the Pathogenesis of Osteoarthritis

Osteoarthritis (OA) is a chronic, progressive, degenerative joint disease characterized by joint pain, stiffness, and limited movement. It presents significant intra- and inter-individual variability-in particular, between genders. Recent research has increasingly focused on the role of adipokines-especially leptin, adiponectin, and resistin-in the development of OA. Adipokines, peptide hormones primarily secreted by adipose tissue, are involved in crucial physiological processes related to metabolism and immunity. They can also impact bone and cartilage turnover by interacting with joint cells such as osteoblasts, osteoclasts, chondrocytes, and mesenchymal stem cells, thereby linking inflammation with bone cartilage homeostasis. This review aims to elucidate the structure and functions of various adipokines, their serum and synovial levels, and their association with clinical presentation and radiographic progression in OA patients, with a focus on differences between sexes. A narrative literature review was conducted using three databases specifically analyzing sex differences. OA patients generally show elevated serum and synovial levels of leptin, chemerin, and visfatin, as well as high plasma levels of resistin and visfatin. In contrast, synovial levels of adiponectin and omentin are reduced in OA patients compared to healthy individuals, with an inverse relationship to disease severity, suggesting a potential protective role. Resistin and leptin were positively correlated with pain severity and radiographic progression, while adiponectin's role in OA remains controversial. Regarding sex differences, male OA patients exhibited higher serum levels of leptin, chemerin, and omentin compared to healthy controls, with a positive correlation to the BMI and estrogen levels, potentially explaining the sexual dimorphism observed in this condition. Studies on visfatin and lipocalin did not reveal significant differences in synovial or serum levels between the sexes. The role of resistin remains controversial. Adipokines influence the joint microenvironment and contribute to the progression of osteoarthritis (OA). However, the precise biological mechanisms are not yet fully understood due to the complex interactions between the metabolic, mechanical, and immune systems. Further research is needed to clarify their roles in OA and to identify targeted therapies for managing this degenerative disease.

Influence of Type 2 Diabetes and Adipose Tissue Dysfunction on Breast Cancer and Potential Benefits from Nutraceuticals Inducible in Microalgae

Breast cancer (BC) represents the most prevalent cancer in women at any age after puberty. From a pathogenetic prospective, despite a wide array of risk factors being identified thus far, poor metabolic health is emerging as a putative risk factor for BC. In particular, type 2 diabetes mellitus (T2DM) provides a perfect example bridging the gap between poor metabolic health and BC risk. Indeed, T2DM is preceded by a status of hyperinsulinemia and is characterised by hyperglycaemia, with both factors representing potential contributors to BC onset and progression. Additionally, the aberrant secretome of the dysfunctional, hypertrophic adipocytes, typical of obesity, characterised by pro-inflammatory mediators, is a shared pathogenetic factor between T2DM and BC. In this review, we provide an overview on the effects of hyperglycaemia and hyperinsulinemia, hallmarks of type 2 diabetes mellitus, on breast cancer risk, progression, treatment and prognosis. Furthermore, we dissect the role of the adipose-tissue-secreted adipokines as additional players in the pathogenesis of BC. Finally, we focus on microalgae as a novel superfood and a source of nutraceuticals able to mitigate BC risk by improving metabolic health and targeting cellular pathways, which are disrupted in the context of T2DM and obesity.

Leptin Is Associated with Testosterone, Nutritional Markers, and Vascular Muscular Dysfunction in Chronic Kidney Disease

Chronic kidney disease (CKD) causes specific hormonal disturbances, such as variations in leptin and testosterone levels and function. These disturbances can promote errors in signaling interaction and cellular information processing and can be implicated in the pathogenesis of atherosclerosis. This study investigates the factors that affect leptin in CKD patients and examines how leptin is related to markers of vascular disease. We conducted a cross-sectional study of 162 patients with CKD in pre-dialysis and dialysis stages. We recorded clinical and laboratory data, including leptin, testosterone, and subclinical atherosclerosis markers like brachial-ankle pulse wave velocity (ba PWV) in pre-dialysis CKD patients and flow-mediated vasodilation (FMD) and nitroglycerin-mediated vasodilation (NMD) in hemodialysis (HD) patients. Leptin was significantly correlated with testosterone in CKD pre-dialysis stages (p < 0.001) and also in HD (p = 0.026), with adipose tissue mass in pre-dialysis stages (p < 0.001), and also in HD (p < 0.001). In women HD patients, leptin correlated with NMD (p = 0.039; r = -0.379); in all HD patients, leptin correlated with C reactive protein (p = 0.007; r = 0.28) and parathormone (p = 0.039; r = -0.220). Our research emphasizes the connection between leptin, adipose tissue, and testosterone in all stages of CKD. Leptin was associated with NMD in HD women and correlated with inflammatory syndrome and parathyroid hormone in all HD patients.

Diet-induced metabolic and immune impairments are sex-specifically modulated by soluble TNF signaling in the 5xFAD mouse model of Alzheimer's disease

Emerging evidence indicates that high-fat, high carbohydrate diet (HFHC) impacts central pathological features of Alzheimer's disease (AD) across both human incidences and animal models. However, the mechanisms underlying this association are poorly understood. Here, we identify compartment-specific metabolic and inflammatory dysregulations that are induced by HFHC diet in the 5xFAD mouse model of AD pathology. We observe that both male and female 5xFAD mice display exacerbated adiposity, cholesterolemia, and dysregulated insulin signaling. Independent of biological sex, HFHC diet also resulted in altered inflammatory cytokine profiles across the gastrointestinal, circulating, and central nervous systems (CNS) compartments demonstrating region-specific impacts of metabolic inflammation. Interestingly, inhibiting the inflammatory cytokine, soluble tumor necrosis factor (TNF) with the brain-permeant soluble TNF inhibitor XPro1595 was able to restore aspects of HFHC-induced metabolic inflammation, but only in male mice. Targeted transcriptomics of CNS regions revealed that inhibition of soluble TNF was sufficient to alter expression of hippocampal and cortical genes associated with beneficial immune and metabolic responses. Collectively, these results suggest that HFHC diet impairs metabolic and inflammatory pathways in an AD-relevant genotype and that soluble TNF has sex-dependent roles in modulating these pathways across anatomical compartments. Modulation of energy homeostasis and inflammation may provide new therapeutic avenues for AD.

Diet-induced metabolic and immune impairments are sex-specifically modulated by soluble TNF signaling in the 5xFAD mouse model of Alzheimer's disease

Emerging evidence indicates that high-fat, high carbohydrate diet (HFHC) impacts central pathological features of Alzheimer's disease (AD) across both human incidences and animal models. However, the mechanisms underlying this association are poorly understood. Here, we identify compartment-specific metabolic and inflammatory dysregulations that are induced by HFHC diet in the 5xFAD mouse model of AD pathology. We observe that both male and female 5xFAD mice display exacerbated adiposity, cholesterolemia, and dysregulated insulin signaling. Independent of biological sex, HFHC diet also resulted in altered inflammatory cytokine profiles across the gastrointestinal, circulating, and central nervous systems (CNS) compartments demonstrating region-specific impacts of metabolic inflammation. In male mice, we note that HFHC triggered increases in amyloid beta, an observation not seen in female mice. Interestingly, inhibiting the inflammatory cytokine, soluble tumor necrosis factor (TNF) with the brain-permeant soluble TNF inhibitor XPro1595 was able to restore aspects of HFHC-induced metabolic inflammation, but only in male mice. Targeted transcriptomics of CNS regions revealed that inhibition of soluble TNF was sufficient to alter expression of hippocampal and cortical genes associated with beneficial immune and metabolic responses. Collectively, these results suggest that HFHC diet impairs metabolic and inflammatory pathways in an AD-relevant genotype and that soluble TNF has sex-dependent roles in modulating these pathways across anatomical compartments. Modulation of energy homeostasis and inflammation may provide new therapeutic avenues for AD.

Twenty-four-hour ambulatory, but not clinic blood pressure associates with leptin in young adults with overweight or obesity: The African-PREDICT study

Hypertension and obesity are known pro-inflammatory conditions, and limited studies explored various blood pressure modalities and inflammatory markers in young adults with overweight or obesity (OW/OB). We assessed the relationship of clinic and 24 h ambulatory blood pressure with an array of inflammatory markers in young adults with OW/OB. This cross-sectional study included women and men of Black and White ethnicity (n = 1194) with a median age of 24.5 ± 3.12 years. Participants were divided into normal weight and OW/OB groups according to body mass index. Clinic and 24 h ambulatory systolic and diastolic blood pressure were measured. Inflammatory markers included leptin, interleukin-6, interleukin-8, tumour necrosis factor-α, adiponectin, interleukin-10, and C-reactive protein. After adjustments for age, sex, and ethnicity, the OW/OB group had higher blood pressure and an overall worse inflammatory profile compared to the normal weight group (all p ≤ 0.024). In the OW/OB group, 24 h systolic (r = 0.22; p < 0.001) and diastolic blood pressure (r = 0.28; p < 0.001) correlated with leptin, independent of age, sex, and ethnicity. In fully adjusted regression models, 24 h systolic blood pressure (adj.R2 = 0.25; β = 0.28; p = 0.035) and diastolic blood pressure (adj.R2 = 0.10; β = 0.32; p = 0.034), associated with leptin in the OW/OB group and significance remained with additional adjustments for visceral adiposity index. Twenty-four-hour ambulatory, but not clinic blood pressure, is related to leptin in young adults with OW/OB. Leptin shows a stronger relationship with adiposity when compared to other inflammatory markers and may play a role in subcutaneous adiposity-related increased blood pressure.

Leptin resistance in children with in utero exposure to maternal obesity and gestational diabetes

BACKGROUND

Leptin resistance occurs with obesity, but it is unknown if individuals at risk for obesity develop leptin resistance prior to obesity.

OBJECTIVE

Investigate whether leptin resistance is independent of weight status in children at risk for obesity due to intrauterine exposure to maternal obesity or gestational diabetes mellitus (GDM).

METHODS

Mother-child dyads (N = 179) were grouped by maternal pregnancy weight and GDM status: (1) normal weight, no GDM; (2) overweight/obesity, no GDM; (3) overweight/obesity with GDM. Children (4-10 years) were further stratified by current body mass index (BMI) <85th or ≥85th percentile. Leptin resistance of children and mothers was calculated as fasting leptin/fat mass index. Two-way ANOVA was used to assess whether leptin concentrations and leptin resistance differed by current weight status or in utero exposure group, after adjusting for race, sex and Tanner stage.

RESULTS

Children with a BMI ≥85th percentile had more leptin resistance than those with a BMI <85th percentile (p < 0.001), but leptin resistance did not differ by in utero exposure. Similarly, leptin resistance in women was associated with weight status and not prior GDM.

CONCLUSIONS

Results suggest that leptin concentrations are associated with obesity but not risk for obesity based on in utero exposure to maternal obesity or GDM.

Adipose tissue fibrosis: the unwanted houseguest invited by obesity

The prevalence of obesity is increasing exponentially across the globe. The lack of effective treatment options for long-term weight loss has magnified the enormity of this problem. Studies continue to demonstrate that adipose tissue holds a biological memory, one of the most important determinant of long-term weight maintenance. This phenomenon is consistent with the metabolically dynamic role of adipose tissue: it adapts and expands to store for excess energy and serves as an endocrine organ capable of synthesizing a number of biologically active molecules that regulate metabolic homeostasis. An important component of the plasticity of adipose tissue is the extracellular matrix, essential for structural support, mechanical stability, cell signaling and function. Chronic obesity upends a delicate balance of extracellular matrix synthesis and degradation, and the ECM accumulates in such a way that prevents the plasticity and function of the diverse cell types in adipose tissue. A series of maladaptive responses among the cells in adipose tissue leads to inflammation and fibrosis, major mechanisms that explain the link between obesity and insulin resistance, risk of type 2 diabetes, cardiovascular disease, and nonalcoholic fatty liver disease. Adipose tissue fibrosis persists after weight loss and further enhances adipose tissue dysfunction if weight is regained. Here, we highlight the current knowledge of the cellular events governing adipose tissue ECM remodeling during the development of obesity. Our goal is to delineate the relationship more clearly between adipose tissue ECM and metabolic disease, an important step toward better defining the pathophysiology of dysfunctional adipose tissue.

Adipokines and Bacterial Metabolites: A Pivotal Molecular Bridge Linking Obesity and Gut Microbiota Dysbiosis to Target

Adipokines are essential mediators produced by adipose tissue and exert multiple biological functions. In particular, adiponectin, leptin, resistin, IL-6, MCP-1 and PAI-1 play specific roles in the crosstalk between adipose tissue and other organs involved in metabolic, immune and vascular health. During obesity, adipokine imbalance occurs and leads to a low-grade pro-inflammatory status, promoting insulin resistance-related diabetes and its vascular complications. A causal link between obesity and gut microbiota dysbiosis has been demonstrated. The deregulation of gut bacteria communities characterizing this dysbiosis influences the synthesis of bacterial substances including lipopolysaccharides and specific metabolites, generated via the degradation of dietary components, such as short-chain fatty acids, trimethylamine metabolized into trimethylamine-oxide in the liver and indole derivatives. Emerging evidence suggests that these bacterial metabolites modulate signaling pathways involved in adipokine production and action. This review summarizes the current knowledge about the molecular links between gut bacteria-derived metabolites and adipokine imbalance in obesity, and emphasizes their roles in key pathological mechanisms related to oxidative stress, inflammation, insulin resistance and vascular disorder. Given this interaction between adipokines and bacterial metabolites, the review highlights their relevance (i) as complementary clinical biomarkers to better explore the metabolic, inflammatory and vascular complications during obesity and gut microbiota dysbiosis, and (ii) as targets for new antioxidant, anti-inflammatory and prebiotic triple action strategies.

Understanding the Consequences of Fatty Bone and Fatty Muscle: How the Osteosarcopenic Adiposity Phenotype Uncovers the Deterioration of Body Composition

Adiposity is central to aging and several chronic diseases. Adiposity encompasses not just the excess adipose tissue but also body fat redistribution, fat infiltration, hypertrophy of adipocytes, and the shifting of mesenchymal stem cell commitment to adipogenesis. Bone marrow adipose tissue expansion, inflammatory adipokines, and adipocyte-derived extracellular vesicles are central to the development of osteopenic adiposity. Adipose tissue infiltration and local adipogenesis within the muscle are critical in developing sarcopenic adiposity and subsequent poorer functional outcomes. Ultimately, osteosarcopenic adiposity syndrome is the result of all the processes noted above: fat infiltration and adipocyte expansion and redistribution within the bone, muscle, and adipose tissues, resulting in bone loss, muscle mass/strength loss, deteriorated adipose tissue, and subsequent functional decline. Increased fat tissue, typically referred to as obesity and expressed by body mass index (the latter often used inadequately), is now occurring in younger age groups, suggesting people will live longer with the negative effects of adiposity. This review discusses the role of adiposity in the deterioration of bone and muscle, as well as adipose tissue itself. It reveals how considering and including adiposity in the definition and diagnosis of osteopenic adiposity, sarcopenic adiposity, and osteosarcopenic adiposity will help in better understanding the pathophysiology of each and accelerate possible therapies and prevention approaches for both relatively healthy individuals or those with chronic disease.

Immunometabolism mRNA expression phenotypes and reprogramming of CD14 in T2DM with or without CVD

BACKGROUND/AIM

Type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD) have a significant impact on the expression of genes in peripheral blood mononuclear cells (PBMCs). The primary objective of this study was to investigate the role of two signaling pathways, STAT1/6, and two important modulators of immunometabolism, leptin and PPARs, in the development of T2DM with and without CVD. Furthermore, the study aimed to assess the correlation between these factors and the dynamics of CD14 in PBMCs. This research was conducted within the context of a growing body of literature on the complex pathophysiology of T2DM and its association with CVD. Prior studies have indicated that T2DM is characterized by an imbalance in immunometabolism and the involvement of various signaling pathways.

MATERIALS AND METHODS

Blood samples were collected from a total of 47 subjects, including 7 healthy volunteers, 20 individuals diagnosed with diabetes and cardiovascular disease (D.CVD) and another 20 individuals diagnosed with diabetes only (D). PBMCs were isolated from these samples, and the expression levels of leptin, PPARγ, PPARα, and CD14 genes were measured using Real-Time PCR.

RESULTS

The most relevant result showed that diabetic patients with CVD had significantly higher levels of leptin expression, which was positively correlated with STAT1 (r = 0.7497, p = 0.0001). On the other hand, diabetic patients without CVD had elevated PPARγ expression, which was strongly correlated with STAT6 (r = 0.8437, p = 0.0001). Interestingly, we found a significant increase in the PPARγ/ PPARα ratio in the D.CVD group compared to the D group (4.273 ± 0.9531; 7.52 ± 3.556, p = 0.0479). Moreover, CD14 expression was significantly reduced in this group compared to diabetic patients without CVD.

CONCLUSION

These findings suggested that the immunometabolic imbalance in T2DM was driven by a STAT1/Leptin phenotype in diabetic patients with CVD and by a STAT6/PPARγ phenotype in diabetic patients without CVD. Taking into account STAT1/Leptin and STAT6/PPARγ profiling could help clinicians identify novel therapeutic targets for T2DM and other related diseases.

Relationship between leptin and white blood cells: a potential role in infection susceptibility and severity-the Olivetti Heart Study

A number of evidence showed an emerging role of leptin on immune system, involving inflammation, and innate and adaptive immunity. Few observational studies have evaluated the relationship between leptin and immunity, albeit with low statistical power and methodological differences. Therefore, the aim of this study was to evaluate the potential role of leptin on the immunity, expressed as white blood cells (WBC)-and its subpopulations, by comprehensive multivariate models in a sample of adult men. A cross-sectional evaluation of a general population comprised 939 subjects participating in the Olivetti Heart Study, with available leptin levels and WBC-and its subpopulations. WBC were significantly and positively associated with leptin, C-reactive protein and HOMA index (p < 0.05), but not with age and anthropometric indices (p > 0.05). The multivariate analysis confirmed the association between leptin and WBC, after accounting for main confounders (p < 0.05). Additional analysis on WBC subpopulations showed a positive and significant correlation between leptin and lymphocytes, monocytes and eosinophils (p < 0.05), but not with neutrophils and basophils (p > 0.05). After stratification by body weight, the positive and significant association between leptin and WBC-and its subpopulations-was found in excess body weight participants. The results of this study indicate a direct relationship between leptin levels and WBC-and its subpopulations-in excess body weight participants. These results support the hypothesis that leptin has modulatory functions on immunity and role in the pathophysiology of immune-related diseases, in particular in those associated with excess body weight.

Effects of an Intervention with Selenium and Coenzyme Q10 on Five Selected Age-Related Biomarkers in Elderly Swedes Low in Selenium: Results That Point to an Anti-Ageing Effect-A Sub-Analysis of a Previous Prospective Double-Blind Placebo-Controlled Randomised Clinical Trial

Background: Ageing is associated with cardiovascular disease (CVD). As no single biomarker reflects the full ageing process, we aimed to investigate five CVD- and age-related markers and the effects of selenium and coenzyme Q10 intervention to elucidate the mechanisms that may influence the course of ageing. Methods: This is a sub-study of a previous prospective double-blind placebo-controlled randomized clinical trial that included 441 subjects low in selenium (mean age 77, 49% women). The active treatment group (n = 220) received 200 µg/day of selenium and 200 mg/day of coenzyme Q10, combined. Blood samples were collected at inclusion and after 48 months for measurements of the intercellular adhesion molecule (ICAM-1), adiponectin, leptin, stem cell factor (SCF) and osteoprotegerin (OPG), using ELISAs. Repeated measures of variance and ANCOVA evaluations were used to compare the two groups. In order to better understand and reduce the complexity of the relationship between the biomarkers and age, factor analyses and structural equation modelling (SEM) were performed, and a structural model is presented. Results: Correlation analyses of biomarker values at inclusion in relation to age, and relevant markers related to inflammation, endothelial dysfunction and fibrosis, demonstrated the biomarkers' association with these pathological processes; however, only ICAM1 and adiponectin were directly correlated with age. SEM analyses showed, however, that the biomarkers ICAM-1, adiponectin, SCF and OPG, but not leptin, all had significant associations with age and formed two independent structural factors, both significantly related to age. While no difference was observed at inclusion, the biomarkers were differently changed in the active treatment and placebo groups (decreasing and increasing levels, respectively) at 48 months (p ≤ 0.02 in all, adjusted), and in the SEM model, they showed an anti-ageing impact. Conclusions: Supplementation with selenium/Q10 influenced the analysed biomarkers in ways indicating an anti-ageing effect, and by applying SEM methodology, the interrelationships between two independent structural factors and age were validated.

Physiological regulation of leptin as an integrative signal of reproductive readiness

Reproductive function is tightly regulated by both environmental and physiological factors. The adipose-derived hormone leptin has been identified as one such critical factor that relays information about peripheral energy availability to the centrally-governed HPG axis to ensure there is sufficient energy availability to support the high energy demands of mammalian reproduction. In the absence of adequate central leptin signaling, reproductive function is suppressed. While leptin levels are predominantly regulated by adiposity, circulating leptin levels are also under the modulatory influence of other factors, such as stress system activation, circadian rhythmicity, and immune activation and the inflammatory response. Furthermore, changes in leptin sensitivity can affect the degree to which leptin exerts its influence on the neuroendocrine reproductive axis. This review will discuss the different mechanisms by which leptin serves to integrate and relay information about metabolic, psychological, environmental and immune conditions to the central neuronal network that governs reproductive function.

New Insights into Adiponectin and Leptin Roles in Chronic Kidney Disease

Chronic kidney disease (CKD) is commonly associated with a high burden of comorbidities and poor clinical outcomes. Malnutrition–inflammation–atherosclerosis syndrome is common in the more severe stages of CKD, suggesting a close interplay for these three comorbid conditions. Both malnutrition and obesity are associated with a disturbed adipokine profile and inflammation, contributing to a higher risk of cardiovascular disease (CVD) events. Adiponectin and leptin have important roles in carbohydrate and lipid metabolism, and in the inflammatory process. The effects of adiponectin and leptin alterations in CKD, which are usually increased, and their association with the different comorbidities found in CKD, will be focused on to understand their crosstalk with the risk of CVD events. Nonetheless, although adiponectin and leptin contribute to a higher risk of CVD events, further studies are warranted to fully clarify their roles, especially when different comorbidities exist.

Metformin attenuates osteoarthritis by targeting chondrocytes, synovial macrophages and adipocytes

OBJECTIVE

To investigate the therapeutic effect and mechanism of metformin on knee osteoarthritis (OA) in normal diet (ND) mice or high-fat diet (HFD)-induced obese mice.

METHODS

Destabilization of the medial meniscus surgery was performed in ND mice or HFD mice, and metformin was administrated in drinking water or not. The changes of OA joint structure, infiltration and polarization of synovial macrophages and circulating and local levels of leptin and adiponectin were evaluated. In vitro, the effects of metformin on chondrocytes and macrophages, and of conditioned mediums derived from mouse abdominal fat on murine chondrogenic cell line ATDC5 and murine macrophage cell line RAW264.7, were detected.

RESULTS

Metformin showed protective effects on OA, characterized by reductions on OARSI score (2.00, 95% CI [1.15-2.86] for ND mice and 3.17, 95% CI [2.37-3.96] for HFD mice) and synovitis score (1.17, 95% CI [0.27-2.06] for ND mice and 2.50, 95% CI [1.49-3.51] for HFD mice) after 10 weeks of treatment, and the effects were more significant in HFD mice than in ND mice. Mechanistically, in addition to decreasing apoptosis and matrix-degrading enzymes expression in chondrocytes as well as infiltration and pro-inflammatory differentiation of synovial macrophages, metformin reduced leptin secretion by adipose tissue in HFD mice.

CONCLUSIONS

Metformin protects against knee OA which could be through reducing apoptosis and catabolism of chondrocytes, and suppressing infiltration and pro-inflammatory polarization of synovial macrophages. For obese mice, metformin has a greater protective effect in knee OA additionally through reducing leptin secretion from adipose tissue.

IL-17A, IL-17E and IL-17F as Potential Biomarkers for the Intensity of Low-Grade Inflammation and the Risk of Cardiovascular Diseases in Obese People

Low-grade inflammation is a factor that predisposes to many obesity-related comorbidities. The immune mechanisms controlling the inflammatory response related to the secretory activity of adipocytes and its consequences for the organism are still under investigation.

METHODS

84 obese adult volunteers (BMI ≥ 30 kg/m²) were tested by BIA. Serum samples were collected to analyze the concentrations of interleukins IL-17A, IL-17E and IL-17F. The subjects completed the original questionnaire, the FFQ-6 food consumption frequency questionnaire and the food diary.

RESULTS

The level of IL-17E and IL-17F was positively correlated with the BMI value and the level of IL-17E increased with the content of subcutaneous fat. Its increased blood concentration was also observed in individuals who declared that they were diagnosed with atherosclerosis and/or were taking beta-blockers. Products that were related with a low level of the above-mentioned interleukins were vegetables, groats, eggs, red meat, fast-food and alcohol. The level of these interleukins was positively correlated with the frequent consumption of confectionery and breakfast cereals. Nutrients that decreased the concentrations of IL-17 isoforms were potassium, iron, vitamins B6 and C, and folic acid.

CONCLUSIONS

Both IL-17E and IL-17F may be closely related to the intensity of low-grade inflammation and be biomarkers of cardiovascular disease risk. Food products or the nutrients they contain may affect the levels of the above-mentioned interleukins as well as IL-17A.

Emerging Insights on the Diverse Roles of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) in Chronic Liver Diseases: Cholesterol Metabolism and Beyond

Chronic liver diseases are commonly associated with dysregulated cholesterol metabolism. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a serine protease of the proprotein convertase family that is mainly synthetized and secreted by the liver, and represents one of the key regulators of circulating low-density lipoprotein (LDL) cholesterol levels. Its ability to bind and induce LDL-receptor degradation, in particular in the liver, increases circulating LDL-cholesterol levels in the blood. Hence, inhibition of PCSK9 has become a very potent tool for the treatment of hypercholesterolemia. Besides PCSK9 limiting entry of LDL-derived cholesterol, affecting multiple cholesterol-related functions in cells, more recent studies have associated PCSK9 with various other cellular processes, including inflammation, fatty acid metabolism, cancerogenesis and visceral adiposity. It is increasingly becoming evident that additional roles for PCSK9 beyond cholesterol homeostasis are crucial for liver physiology in health and disease, often contributing to pathophysiology. This review will summarize studies analyzing circulating and hepatic PCSK9 levels in patients with chronic liver diseases. The factors affecting PCSK9 levels in the circulation and in hepatocytes, clinically relevant studies and the pathophysiological role of PCSK9 in chronic liver injury are discussed.

Elevated serum leptin levels are associated with lower renal function among middle-aged and elderly adults in Taiwan, a community-based, cross-sectional study

BACKGROUND

Plasma leptin is considered a risk factor for obesity and cardio-metabolic disease, but the link between serum leptin and renal function is still under evaluation. In our study, we focused on the relationship between serum leptin and renal function, and we investigated the relationship in more detail.

METHODS

The 396 middle-aged and elderly Taiwanese adults recruited for our health survey were the subject of our research. All participants agreed to participate and signed a consent form before they joined and completed our study. We divided the participants into three groups according to eGFR tertiles and analyzed the parameters between each group. Then, we used Pearson's correlation test to investigate the relationship between eGFR levels and cardio-metabolic risk factors with adjustment for age. The scatter plot indicates the trend between serum leptin levels and eGFR levels. Participants were reclassified into three subgroups according to their leptin levels and the bar chart reveals the prevalence of chronic kidney disease (CKD) in each group. Finally, we used multivariate linear regression to evaluate the relationship between serum leptin and eGFR levels with adjustment for age, sex, smoking status, drinking status, body mass index (BMI), uric acid levels, hypertension (HTN), diabetes mellitus (DM), and dyslipidemia.

RESULTS

In our study, we analyzed the data from 396 eligible participants. A total of 41.4% of the participants were male, and the average age of all participants was 64.81 years ( ± 8.78). The participants in the high eGFR group were more likely to have lower serum leptin levels. Furthermore, eGFR values were negatively correlated with serum leptin levels even after adjustment for age. The prevalence of CKD in the high serum leptin group was higher than that in the low serum leptin group. Serum leptin levels showed significant negative correlations with eGFR levels (β=-0.14, p<0.01) in the multivariate linear regression after adjusting for age, sex, smoking status, drinking status, BMI, uric acid levels, HTN, DM, and dyslipidemia.

CONCLUSION

According to our study, serum leptin levels show a negative relationship with eGFR levels in middle-aged and elderly people in Taiwan. In addition, high serum leptin levels could be an novel marker to survey kidney failure in clinical practices.

Natural and Synthetic Estrogens in Chronic Inflammation and Breast Cancer

The oncogenic role of estrogen receptor (ER) signaling in breast cancer has long been established. Interaction of estrogen with estrogen receptor (ER) in the nucleus activates genomic pathways of estrogen signaling. In contrast, estrogen interaction with the cell membrane-bound G-protein-coupled estrogen receptor (GPER) activates the rapid receptor-mediated signaling transduction cascades. Aberrant estrogen signaling enhances mammary epithelial cell proliferation, survival, and angiogenesis, hence is an important step towards breast cancer initiation and progression. Meanwhile, a growing number of studies also provide evidence for estrogen's pro- or anti-inflammatory roles. As other articles in this issue cover classic ER and GPER signaling mediated by estrogen, this review will discuss the crucial mechanisms by which estrogen signaling influences chronic inflammation and how that is involved in breast cancer. Xenoestrogens acquired from plant diet or exposure to industrial products constantly interact with and alter innate estrogen signaling at various levels. As such, they can modulate chronic inflammation and breast cancer development. Natural xenoestrogens generally have anti-inflammatory properties, which is consistent with their chemoprotective role in breast cancer. In contrast, synthetic xenoestrogens are proinflammatory and carcinogenic compounds that can increase the risk of breast cancer. This article also highlights important xenoestrogens with a particular focus on their role in inflammation and breast cancer. Improved understanding of the complex relationship between estrogens, inflammation, and breast cancer will guide clinical research on agents that could advance breast cancer prevention and therapy.

Autoimmune-mediated renal disease and hypertension

Hypertension is a major risk factor for cardiovascular disease, chronic kidney disease (CKD), and mortality. Troublingly, hypertension is highly prevalent in patients with autoimmune renal disease and hastens renal functional decline. Although progress has been made over the past two decades in understanding the inflammatory contributions to essential hypertension more broadly, the mechanisms active in autoimmune-mediated renal diseases remain grossly understudied. This Review provides an overview of the pathogenesis of each of the major autoimmune diseases affecting the kidney that are associated with hypertension, and describes the current state of knowledge regarding hypertension in these diseases and their management. Specifically, discussion focuses on Systemic Lupus Erythematosus (SLE) and Lupus Nephritis (LN), Immunoglobulin A (IgA) Nephropathy, Idiopathic Membranous Nephropathy (IMN), Anti-Neutrophil Cytoplasmic Antibody (ANCA)-associated glomerulonephritis, and Thrombotic Thrombocytopenic Purpura (TTP). A summary of disease-specific animal models found to exhibit hypertension is also included to highlight opportunities for much needed further investigation of underlying mechanisms and novel therapeutic approaches.