BACKGROUND/OBJECTIVES: The NAD+ precursor nicotinamide riboside (NR) is a type of vitamin B3 found in cow's milk and yeast-containing food products such as beer. Recent studies suggested that NR prevents hearing loss, high-fat diet-induced obesity, Alzheimer's disease, and mitochondrial myopathy. The objective of this study was to investigate the effects of NR on inflammation and mitochondrial biogenesis in AML12 mouse hepatocytes. MATERIALS/METHODS: A subset of hepatocytes was treated with palmitic acid (PA; 250 µM) for 48 h to induce hepatocyte steatosis. The hepatocytes were treated with NR (10 µM and 10 mM) for 24 h with and without PA. The cell viability and the levels of sirtuins, inflammatory markers, and mitochondrial markers were analyzed. RESULTS: Cytotoxicity of NR was examined by PrestoBlue assay. Exposure to NR had no effect on cell viability or morphology. Gene expression of sirtuin 1 (Sirt1) and Sirt3 was significantly upregulated by NR in PA-treated hepatocytes. However, Sirt1 activities were increased in hepatocytes treated with low-dose NR. Hepatic pro-inflammatory markers including tumor necrosis factor-alpha and interleukin-6 were decreased in NR-treated cells. NR upregulated anti-inflammatory molecule adiponectin, and, tended to down-regulate hepatokine fetuin-A in PA-treated hepatocytes, suggesting its inverse regulation on these cytokines. NR increased levels of mitochondrial markers including peroxisome proliferator-activated receptor γ coactivator-1α, carnitine palmitoyltransferase 1, uncoupling protein 2, transcription factor A, mitochondrial and mitochondrial DNA in PA-treated hepatocytes. CONCLUSIONS: These data demonstrated that NR attenuated hepatic inflammation and increased levels of mitochondrial markers in hepatocytes.
Adiponectin ; alpha-2-HS-Glycoprotein ; Alzheimer Disease ; Animals ; Beer ; Carnitine O-Palmitoyltransferase ; Cell Survival ; Cytokines ; DNA, Mitochondrial ; Fatty Liver ; Gene Expression ; Hearing Loss ; Hepatocytes ; Inflammation ; Interleukin-6 ; Mice ; Milk ; Mitochondria ; Mitochondrial Myopathies ; Niacin ; Niacinamide ; Obesity ; Organelle Biogenesis ; Palmitic Acid ; Peroxisomes ; Sirtuin 1 ; Sirtuins ; Transcription Factors ; Tumor Necrosis Factor-alpha

BACKGROUND: Fetuin-A is a hepatokine that involved in the pathogenesis of insulin resistance. Previous epidemiological studies have found a positive association between blood fetuin-A and type 2 diabetes mellitus (T2DM) risk among Caucasians and African Americans. We aimed to investigate the prospective relationship between fetuin-A and T2DM in an Asian population for the first time. METHODS: A nested case-control study was established within a prospective cohort of Chinese living in Singapore. At blood collection (1999 to 2004), all participants were free of diagnosed T2DM and aged 50 to 79 years. At subsequent follow-up (2006 to 2010), 558 people reported to have T2DM and were classified as incident cases, and 558 controls were randomly chosen from the participants who did not develop T2DM to match with cases on age, sex, dialect group, and date of blood collection. Plasma fetuin-A levels were measured retrospectively in cases and controls using samples collected at baseline. Conditional logistic regression models were used to compute the odds ratio (OR) and 95% confidence interval (CI). Restricted cubic spline analysis was used to examine a potential non-linear association between fetuin-A levels and T2DM risk. RESULTS: Compared with those in the lowest fetuin-A quintile, participants in the highest quintile had a two-fold increased risk of developing T2DM (OR, 2.06; 95% CI, 1.21 to 3.51). A non-linear association was observed (P nonlinearity=0.005), where the association between fetuin-A levels and T2DM risk plateaued at plasma concentrations around 830 µg/mL. CONCLUSION: There is a positive association between plasma fetuin-A levels and risk of developing T2DM in this Chinese population.
African Americans ; alpha-2-HS-Glycoprotein ; Asian Continental Ancestry Group ; Case-Control Studies ; Cohort Studies ; Diabetes Mellitus, Type 2 ; Epidemiologic Studies ; Epidemiology ; Follow-Up Studies ; Humans ; Insulin Resistance ; Logistic Models ; Odds Ratio ; Plasma ; Prospective Studies ; Retrospective Studies ; Singapore

OBJECTIVE: The aim of this study was to compare serum fetuin-A levels and oxidative stress markers, as indicators of insulin resistance, in women with polycystic ovary syndrome (PCOS) and in healthy controls. METHODS: This prospective case-control study included 46 patients with PCOS and 48 age- and body mass index–matched control women. Levels of serum hormones, fetuin-A, and oxidative stress markers were measured in blood samples taken during the early follicular period from each participant. RESULTS: Follicle-stimulating hormone (FSH), luteinising hormone (LH), total testosterone levels, and the LH/FSH ratio were found to be significantly higher in women with PCOS than in controls. Serum total antioxidant status, total oxidant status, and oxidative stress index parameters all indicated significantly higher levels of oxidative stress in PCOS patients than in controls. Serum fetuin-A levels, which were analyzed as an indicator of insulin resistance, were higher in the PCOS group than in the control group (210.26±65.06 µg/mL and 182.68±51.20 µg/mL, respectively; p=0.024). CONCLUSION: The data obtained from the present study suggest that higher levels of both serum fetuin-A and oxidative stress markers might be related with PCOS.
alpha-2-HS-Glycoprotein* ; Case-Control Studies ; Female ; Follicle Stimulating Hormone ; Humans ; Insulin Resistance ; Oxidative Stress* ; Polycystic Ovary Syndrome* ; Prospective Studies ; Testosterone

The Healthy Eating Index-2010 (HEI-2010) assesses compliance with the 2010 Dietary Guidelines for Americans. Studies suggest that adherence to the HEI-2010 is related to lower the risk of type 2 diabetes (T2D). Fetuin-A, a novel biomarker for T2D, may play a linking role in the inverse association between HEI-2010 and T2D. Thus, a case-control analysis involving 107 patients with T2D and107 healthy subjects was conducted to determine the association between HEI-2010 and serum fetuin-A levels. The results of simple regression analysis showed that fetuin-A levels were positively associated with full name of body mass index (BMI) (p < 0.001), waist circumference (WC) (p < 0.001), fasting blood glucose (FBG) (p < 0.001), triglycerides (TG) (p = 0.003), gamma-glutamyl transferase (GGT) (p < 0.001), and homeostasis model assessment of insulin resistance (HOMA-IR) (p =0.001) and negatively associated with physical activity (PA) (p < 0.001), high-density lipoprotein (HDL) (p = 0.022), and HEI-2010 (p < 0.001) in all subjects. After controlling for confounders, the inverse association between fetuin-A and HEI-2010 remained significant in the subjects with T2D (β = −0.386; p < 0.001), 107 healthy controls (β = −0.237; p = 0.028), and all subjects (β = −0.298; p < 0.001). In conclusion, the present results suggested that higher quality diet assessed by HEI-2010 associates with lower serum fetuin-A levels in people with and without T2D. More studies are needed to confirm these findings.
alpha-2-HS-Glycoprotein* ; Blood Glucose ; Body Mass Index ; Case-Control Studies* ; Compliance ; Diet ; Eating* ; Fasting ; Healthy Volunteers ; Homeostasis ; Humans ; Insulin Resistance ; Lipoproteins ; Motor Activity ; Nutrition Policy ; Transferases ; Triglycerides ; Waist Circumference

The Healthy Eating Index-2010 (HEI-2010) assesses compliance with the 2010 Dietary Guidelines for Americans. Studies suggest that adherence to the HEI-2010 is related to lower the risk of type 2 diabetes (T2D). Fetuin-A, a novel biomarker for T2D, may play a linking role in the inverse association between HEI-2010 and T2D. Thus, a case-control analysis involving 107 patients with T2D and107 healthy subjects was conducted to determine the association between HEI-2010 and serum fetuin-A levels. The results of simple regression analysis showed that fetuin-A levels were positively associated with full name of body mass index (BMI) (p < 0.001), waist circumference (WC) (p < 0.001), fasting blood glucose (FBG) (p < 0.001), triglycerides (TG) (p = 0.003), gamma-glutamyl transferase (GGT) (p < 0.001), and homeostasis model assessment of insulin resistance (HOMA-IR) (p =0.001) and negatively associated with physical activity (PA) (p < 0.001), high-density lipoprotein (HDL) (p = 0.022), and HEI-2010 (p < 0.001) in all subjects. After controlling for confounders, the inverse association between fetuin-A and HEI-2010 remained significant in the subjects with T2D (β = −0.386; p < 0.001), 107 healthy controls (β = −0.237; p = 0.028), and all subjects (β = −0.298; p < 0.001). In conclusion, the present results suggested that higher quality diet assessed by HEI-2010 associates with lower serum fetuin-A levels in people with and without T2D. More studies are needed to confirm these findings.
alpha-2-HS-Glycoprotein* ; Blood Glucose ; Body Mass Index ; Case-Control Studies* ; Compliance ; Diet ; Eating* ; Fasting ; Healthy Volunteers ; Homeostasis ; Humans ; Insulin Resistance ; Lipoproteins ; Motor Activity ; Nutrition Policy ; Transferases ; Triglycerides ; Waist Circumference

BACKGROUND: Behcet's disease (BD) is a chronic, recurrent inflammatory systemic vasculitis. Evidence for increased atherosclerosis in BD has been observed. The relation between cardiovascular risk factors and increased atherosclerosis in patients with BD is still controversial. OBJECTIVE: We performed this study to evaluate arterial stiffness in patients with BD by using noninvasive radiological methods such as carotid artery intima-media thickness (CIMT), ankle-brachial pressure index (ABPI), coronary artery calcium score (CACaS), and their relation to serum fetuin-A levels, which was recently found to be important in vascular calcification. METHODS: This prospective study included 26 patients with BD and 25 control subjects. In all patients, the CIMT, ABPI, CACaS, and serum fetuin-A levels were examined. RESULTS: The CIMT and CACaS were statistically higher and the ABPI was statistically lower in BD patients than in the control group. All p-values were <0.001. Positive correlations were found between the CACaS and CIMT, and negative correlations were found between the CACaS and ABPI. Although the values of fetuin-A were higher in BD, the difference was not statistically significant (p=0.064). However, the correlations found between fetuin-A levels and CIMT and between fetuin-A levels and CACaS were significant. CONCLUSION: The CIMT, CACaS, and ABPI are all useful in detecting structural and functional vascular damage in BD.
alpha-2-HS-Glycoprotein* ; Ankle Brachial Index ; Atherosclerosis ; Calcium* ; Cardiovascular Diseases ; Carotid Arteries ; Carotid Intima-Media Thickness ; Case-Control Studies* ; Coronary Vessels* ; Humans ; Methods* ; Prospective Studies ; Risk Factors ; Systemic Vasculitis ; Vascular Calcification ; Vascular Stiffness*

BACKGROUND: Selenoprotein P (SEPP1) and fetuin-A, both circulating liver-derived glycoproteins, are novel biomarkers for insulin resistance and nonalcoholic fatty liver disease. However, the effect of exendin-4 (Ex-4), a glucagon-like peptide-1 receptor agonist, on the expression of hepatokines, SEPP1, and fetuin-A, is unknown. METHODS: The human hepatoma cell line HepG2 was treated with palmitic acid (PA; 0.4 mM) and tunicamycin (tuni; 2ug/ml) with or without exendin-4 (100 nM) for 24 hours. The change in expression of PA-induced SEPP1, fetuin-A, and endoplasmic reticulum (ER) stress markers by exendin-4 treatment were evaluated using quantitative real-time reverse transcription polymerase chain reaction and Western blotting. Transfection of cells with AMP-activated protein kinase (AMPK) small interfering RNA (siRNA) was performed to establish the effect of exendin-4-mediated AMPK in the regulation of SEPP1 and fetuin-A expression. RESULTS: Exendin-4 reduced the expression of SEPP1, fetuin-A, and ER stress markers including PKR-like ER kinase, inositol-requiring kinase 1alpha, activating transcription factor 6, and C/EBP homologous protein in HepG2 cells. Exendin-4 also reduced the expression of SEPP1 and fetuin-A in cells treated with tunicamycin, an ER stress inducer. In cells treated with the AMPK activator 5-aminoidazole-4-carboxamide ribonucleotide (AICAR), the expression of hepatic SEPP1 and fetuin-A were negatively related by AMPK, which is the target of exendin-4. In addition, exendin-4 treatment did not decrease SEPP1 and fetuin-A expression in cells transfected with AMPK siRNA. CONCLUSION: These data suggest that exendin-4 can attenuate the expression of hepatic SEPP1 and fetuin-A via improvement of PA-induced ER stress by AMPK.
Activating Transcription Factor 6 ; alpha-2-HS-Glycoprotein* ; AMP-Activated Protein Kinases* ; Blotting, Western ; Carcinoma, Hepatocellular ; Cell Line ; Endoplasmic Reticulum ; Endoplasmic Reticulum Stress* ; Fatty Liver ; Glucagon-Like Peptide 1 ; Glycoproteins ; Hep G2 Cells ; Humans ; Insulin Resistance ; Palmitic Acid ; Phosphotransferases ; Polymerase Chain Reaction ; Reverse Transcription ; RNA, Small Interfering ; Selenoprotein P ; Transfection ; Tunicamycin ; Biomarkers ; Glucagon-Like Peptide-1 Receptor

Non-alcoholic fatty liver disease, which is considered a hepatic manifestation of metabolic syndrome, independently increases the risks of developing cardiovascular disease (CVD) and type 2 diabetes mellitus. Recent emerging evidence suggests that a group of predominantly liver-derived proteins called hepatokines directly affect the progression of atherosclerosis by modulating endothelial dysfunction and infiltration of inflammatory cells into vessel walls. Here, we summarize the role of the representative hepatokines fibroblast growth factor 21, fetuin-A, and selenoprotein P in the progression of CVD.
alpha-2-HS-Glycoprotein ; Atherosclerosis ; Cardiovascular Diseases* ; Diabetes Mellitus, Type 2 ; Fatty Liver ; Fibroblast Growth Factors ; Obesity* ; Selenoprotein P

OBJECTIVETo investigate the association of fetuin-A with residual renal function and carotid artery calcification in patients with chronic kidney disease (CKD).

METHODSBlood examples were collected form 60 CKD patients in stages CKD3 to CKD5 (20 patients per stage) for measurement of serum fetuin-A, albumin, calcium, phosphorus and parathyroid hormone, cholesterol, triglycercide, low-density lipoprotein, and high-density lipoprotein. MDRD equation was used to calculate the estimated glomerular filtration rate (eGFR), and ELISA was used to detect serum fetuin-A. Color Doppler ultrasound was performed to measure carotid intima-media thickness (CIMT).

RESULTSAs the eGFR decreased, serum fetuin-A significantly decreased in CKD5 stage compared with that in CKD4 stage (P<0.05); compared with that in CKD3 stage, serum fetuin-A level was significantly lowered in CKD4 stage (P<0.05). Linear regression analysis suggested a significant positive correlation between fetuin-A and eGFR. The rate of carotid artery calcification was the highest in CKD5 stage. Rank correlation analysis showed a negative correlation between fetuin-A and cIMT, and logistic regression analysis identified decreased serum Fetuin-A as a risk factor of carotid artery calcification.

CONCLUSIONSerum fetuin-A decreases following the decrease in eGFR, and decreased serum Fetuin-A level is a risk factor of carotid artery calcification in CKD patients.

Adult ; Calcinosis ; etiology ; Carotid Artery Diseases ; etiology ; Carotid Intima-Media Thickness ; Female ; Glomerular Filtration Rate ; Humans ; Male ; Middle Aged ; Renal Insufficiency, Chronic ; blood ; complications ; physiopathology ; Risk Factors ; alpha-2-HS-Glycoprotein ; metabolism

BACKGROUND/AIMS: Osteoprotegerin (OPG) and fetuin-A are vascular calcification regulators that may be related to high cardiovascular (CV) mortality in hemodialysis (HD) patients. We evaluated the relationship between OPG, fetuin-A, and pulse wave velocity (PWV), a marker of vascular stiffness, and determined whether OPG and fetuin-A were independent predictors of CV events in HD patients. METHODS: We conducted a prospective observational study in 97 HD patients. OPG and fetuin-A were measured at baseline and arterial stiffness was evaluated by PWV. All patients were stratified into tertiles according to serum OPG levels. RESULTS: A significant trend was observed across increasing serum OPG concentration tertiles for age, HD duration, systolic blood pressure, cholesterol, triglycerides, and PWV. Multiple linear regression analysis revealed that diabetes (beta = 0.430, p = 0.000) and OPG levels (beta = 0.308, p = 0.003) were independently associated with PWV. The frequency of new CV events was significantly higher in the upper OPG tertiles compared with those in the lower OPG tertiles. In Cox proportional hazards analysis, upper tertiles of OPG levels were significantly associated with CV events (hazard ratio = 4.536, p = 0.011). CONCLUSIONS: Serum OPG, but not fetuin-A, levels were closely associated with increased vascular stiffness, and higher OPG levels may be independent predictors of new CV events in HD patients.
Adult ; Aged ; Biological Markers/blood ; Cardiovascular Diseases/blood/diagnosis/*etiology/mortality/physiopathology ; Female ; Humans ; Kaplan-Meier Estimate ; Linear Models ; Male ; Middle Aged ; Multivariate Analysis ; Osteoprotegerin/*blood ; Predictive Value of Tests ; Prognosis ; Proportional Hazards Models ; Prospective Studies ; Pulse Wave Analysis ; *Renal Dialysis/adverse effects/mortality ; Renal Insufficiency, Chronic/complications/diagnosis/mortality/*therapy ; Risk Factors ; Up-Regulation ; *Vascular Stiffness ; alpha-2-HS-Glycoprotein/analysis