Fetuin-A and risk of diabetes-related vascular complications: a prospective study

Background Fetuin-A is a hepatokine which has the capacity to prevent vascular calcification. Moreover, it is linked to the induction of metabolic dysfunction, insulin resistance and associated with increased risk of diabetes. It has not been clarified whether fetuin-A associates with risk of vascular, specifically microvascular, complications in patients with diabetes. We aimed to investigate whether pre-diagnostic plasma fetuin-A is associated with risk of complications once diabetes develops. Methods Participants with incident type 2 diabetes and free of micro- and macrovascular disease from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort (n = 587) were followed for microvascular and macrovascular complications (n = 203 and n = 60, respectively, median follow-up: 13 years). Plasma fetuin-A was measured approximately 4 years prior to diabetes diagnosis. Prospective associations between baseline fetuin-A and risk of complications were assessed with Cox regression. Results In multivariable models, fetuin-A was linearly inversely associated with incident total and microvascular complications, hazard ratio (HR, 95% CI) per standard deviation (SD) increase: 0.86 (0.74; 0.99) for total, 0.84 (0.71; 0.98) for microvascular and 0.92 (0.68; 1.24) for macrovascular complications. After additional adjustment for cardiometabolic plasma biomarkers, including triglycerides and high-density lipoprotein, the associations were slightly attenuated: 0.88 (0.75; 1.02) for total, 0.85 (0.72; 1.01) for microvascular and 0.95 (0.67; 1.34) for macrovascular complications. No interaction by sex could be observed (p > 0.10 for all endpoints). Conclusions Our data show that lower plasma fetuin-A levels measured prior to the diagnosis of diabetes may be etiologically implicated in the development of diabetes-associated microvascular disease.

The Roles and Associated Mechanisms of Adipokines in Development of Metabolic Syndrome

Metabolic syndrome is a cluster of metabolic indicators that increase the risk of diabetes and cardiovascular diseases. Visceral obesity and factors derived from altered adipose tissue, adipokines, play critical roles in the development of metabolic syndrome. Although the adipokines leptin and adiponectin improve insulin sensitivity, others contribute to the development of glucose intolerance, including visfatin, fetuin-A, resistin, and plasminogen activator inhibitor-1 (PAI-1). Leptin and adiponectin increase fatty acid oxidation, prevent foam cell formation, and improve lipid metabolism, while visfatin, fetuin-A, PAI-1, and resistin have pro-atherogenic properties. In this review, we briefly summarize the role of various adipokines in the development of metabolic syndrome, focusing on glucose homeostasis and lipid metabolism.

Clinical Significance of the Fetuin-A-to-Adiponectin Ratio in Obese Children and Adolescents with Diabetes Mellitus

Fetuin-A and adiponectin are inflammatory cytokines associated with obesity and insulin resistance. This study aimed to examine the fetuin-A-to-adiponectin ratio (FAR) in diabetic children and to determine the role of FAR. A total of 54 children and adolescents with diabetes mellitus (DM) and 44 controls aged 9–16 years were included in this study. Clinical characteristics, including plasma fetuin-A and adiponectin levels, were compared with respect to body mass index (BMI) and diabetes type. Of 98 children, 54.1% were obese, whereas 18.4% were obese and diabetic. FAR was higher in obese children with DM than in non-obese children and also in type 2 DM children than in type 1. FAR showed a stronger association with BMI than with fetuin-A and adiponectin individually, and its association was more prominent in diabetic children than in controls. BMI was a risk factor for increased FAR. Plasma fetuin-A was elevated in obese children, and its association with insulin resistance and β cell function seemed more prominent in diabetic children after adjustment for adiponectin. Thus, FAR could be a useful surrogate for the early detection of childhood metabolic complications in diabetic children, particularly those who are obese.

Study of risk factors for the osteoporosis development in rheumatoid arthritis in real clinical practice

Introduction. Osteoporosis is a common complication of rheumatoid arthritis. Its development is associated with the mechanisms underlying in the progression of autoimmune inflammatory diseases and therapeutic approaches used for them. The study of risk factors for osteoporosis can contribute to the clarification of its pathogenesis components, as well as the development of new methods for prevention, diagnosis and treatment of this condition.Aim. To study the role of anamnestic, clinical and laboratory factors for secondary osteoporosis in women with rheumatoid arthritis.Materials and methods. 102 women with rheumatoid arthritis were enrolled in our study. Exclusion criterias were type 2 diabetes mellitus, hepatic cirrhosis, hepatocarcinoma and level of alanine aminotransferase ≥ than 3 upper limit ofnormal. The cumulative dose, duration and daily dose of glucocorticoids (GC) were determined by patient intake. All patients undergone standard clinical and immunological examination. Serum fetuin-A, 25-hydroxycalciferol, C-telopeptide of collagen I type, N-terminal propeptide of collagen I type levels were determined using ELISA. X-ray of afflicted joints and dual-energy x-ray absorptiometry were performed. Statistical analysis was performed using conventional methods. Forced data entry was used to perform multiple logistic regression. Hereinafter data is presented as odds ratio (OR) and 95% confirmation intervals (CI).Results. OR for osteoporosis were higher in women of age ≥ 58.5 years (OR 1,07 (1.02–1.12)), body mass index (BMI) ≤ 27 kg/m2 (OR 1.1 (1.01–1.2)), cumulative dose of GC ≥ 7.6 g (OR 1.09 (1.02–1.17), serum fetuin-A levels ≤ 660 μg/ml (OR 1,05 (1,01–1,09) and if the duration of GC intake is more than 3 months (hereinafter if dose of glucocorticoids is ≥ 5 mg for prednisolone daily) (OR 12.3 (4.12–36.5). Adjusted OR for osteoporosis were higher in women of age ≥ 58.5 years old (adjOR 1.08 (1.01–1.16), serum fetuin-A levels ≤ 660 μg/ml (adjOR 1.08 (1.01–1.15) andif the duration of GC intake is ≥ than 3 months (adjOR 12.1 (1.44–102.3).Conclusions. Women with RA of ≥ than 58.5 years old, duration of GCs intake more than 3 months and serum fetuin-A levels ≤ than 660 μg/ml had higher odds for osteoporosis.These are independent factors for osteoporosis in women with rheumatoid arthritis, whichshould be used in patient’s management.

Fetuin-A Alleviates Neuroinflammation Against Traumatic Brain Injury-Induced Microglial Necroptosis By Regulating Nrf-2/HO-1 Pathway

Background: The microglia-mediated inflammatory response is a vital mechanism of secondary damage following traumatic brain injury (TBI), but its underlying mechanism of microglial activation is unclear. Methods: Controlled cortical impact (CCI) was induced in adult male C57BL/6J mice, and we also used glutamate to construct a classical in vitro injury model in BV2 cell line. The activation of microglia was determined by western blot assessments and immunostaining. The inflammatory factors were determined by ELLSA. The oxidative stress marker and mitochondrial ROS were determined by immunoblotting and MitoSox Red staining. Transmission electron microscopy (TEM) was used to observe a typical morphology of necroptotic cells. Results: Our quantitative proteomics identified 2499 proteins, 157 were significantly differentially expressed between brain tissues at 6 hours after CCI (CCI6h) and sham groups, and 109 were significantly differentially expressed between CCI24h and sham brain tissues. Moreover, compared with sham groups, the terms “acute-phase response”, “inflammation”, and “protein binding” were significantly enriched in CCI groups. Interestingly, fetuin-A, a liver-secreted acute-phase glycoprotein, was involved in these biological processes. Using experimental TBI models, we found that the fetuin-A level peaked at 6 h and then decreased gradually. Importantly, we showed that fetuin-A reduced the cortical lesion volume and edema area and inhibited the inflammatory response, which was associated with suppressing microglial necroptosis, thus decreasing microglial polarization to the M1 phenotype. Furthermore, administration of fetuin-A attenuated mitochondrial oxidative stress in glutamate-treated BV2 cells, which is a critical mechanism of necroptosis suppression. In addition, we demonstrated that fetuin-A treatment promoted translocation of nuclear factor erythroid 2-related factor 2 (Nrf-2) from the cytoplasm to the nucleus in vivo; however, the Nrf-2 inhibitor ML385 and si-heme oxygenase-1 (HO-1) disrupted the regulation of oxidative stress by fetuin-A and induced increased ROS levels and necroptosis in glutamate-treated BV2 cells. Interestingly, the mechanism of fetuin-A in BV2 cells also protects neurons from adverse factors in co-culture assays.Conclusions: Our results demonstrate that fetuin-A activates Nrf-2/HO-1, suppresses oxidative stress and necroptosis levels, and thereby attenuates the abnormal inflammatory response following TBI, providing a potential therapeutic strategy for TBI treatment.

Fetuin-A regulates adipose tissue macrophage content and activation in insulin resistant mice through MCP-1 and iNOS: Involvement of IFNγ-JAK2-STAT1 pathway

In the context of obesity-induced adipose tissue inflammation, migration of macrophages and their polarization from predominantly anti-inflammatory to proinflammatory subtype is considered a pivotal event in the loss of adipose insulin sensitivity. Two major chemoattractants, monocyte chemoattractant protein-1 (MCP-1) and Fetuin A (FetA), have been reported to stimulate macrophage migration into inflamed adipose tissue instigating inflammation. Moreover, FetA could notably modulate macrophage polarization, yet the mechanism(s) is unknown. The present study was undertaken to elucidate the mechanistic pathway involved in the actions of FetA and MCP-1 in obese adipose tissue. We found that FetA knockdown in high fat diet (HFD) fed mice could significantly subdue the augmented MCP-1 expression and reduce adipose tissue macrophage (ATM) content thereby indicating that MCP-1 is being regulated by FetA. Additionally, knockdown of FetA in HFD mice impeded the expression of inducible nitric oxide synthase (iNOS) reverting macrophage activation from mostly proinflammatory to anti-inflammatory state. It was observed that the stimulating effect of FetA on MCP-1 and iNOS was mediated through interferon γ (IFNγ) induced activation of JAK2-STAT1-NOX4 pathway. Furthermore, we detected that the enhanced IFNγ expression was accounted by the stimulatory effect of FetA upon the activities of both cJun and JNK. Taken together, our findings revealed that obesity-induced FetA acts as a master upstream regulator of adipose tissue inflammation by regulating MCP-1 and iNOS expression through JNK-cJun-IFNγ-JAK2-STAT1 signaling pathway. This study opened a new horizon in understanding the regulation of ATM content and activation in conditions of obesity-induced insulin resistance.