fetuin-A Expression Research Articles

Improvement of salivary biomarkers vitronectin and fetuin-A levels in periodontitis patients with coronary artery disease post scaling and root planing.

Two biomarkers that are gaining attention for their roles in the progression of both periodontal and cardiovascular diseases are vitronectin and fetuin-A. This study evaluated vitronectin and fetuin-A expression in saliva samples of periodontitis (P) patients with and without coronary artery disease (CAD) after scaling and root planing (SRP). Sixty patients were divided into three groups: PH+SH (periodontally and systemically healthy), P (stage II/III grade B periodontitis), and P+CAD (periodontitis with CAD). Demographic, periodontal, and cardiac parameters were recorded. Unstimulated saliva samples were collected at baseline (day 0) and after SRP. On day 90, periodontal parameters and vitronectin/fetuin-A expression were reassessed. P+CAD patients had higher age, weight, BMI, and lower income (p<.001,.025,.002,<.001, respectively), along with elevated plaque index, bleeding on probing, probing pocket depth, and reduced clinical attachment levels (p<.001). Vitronectin was elevated, while fetuin-A was lower in P+CAD, but both improved post-SRP (p<.001). Enhanced vitronectin and fetuin-A levels post-SRP indicate their potential as biomarkers and therapeutic targets for both periodontal and CAD.

Dietary coconut oil lowered circulating fetuin-A levels and hepatic expression of fetuin-A in KK/TaJcl mice

Dietary coconut oil lowered circulating fetuin-A levels and hepatic expression of fetuin-A in KK/TaJcl mice

Apigenin targets fetuin-A to ameliorate obesity-induced insulin resistance.

Fetuin-A, a hepatokine secreted by hepatocytes, binds to insulin receptors and consequently impairs the activation of the insulin signaling pathway, leading to insulin resistance. Apigenin, a flavonoid isolated from plants, has beneficial effects on insulin resistance; however, its regulatory mechanisms are not fully understood. In the present study, we investigated the molecular mechanisms underlying the protective effects of apigenin on insulin resistance. In Huh7 cells, treatment with apigenin decreased the mRNA expression of fetuin-A by decreasing reactive oxygen species-mediated casein kinase 2α (CK2α)-nuclear factor kappa-light-chain-enhancer of activated B activation; besides, apigenin decreased the levels of CK2α-dependent fetuin-A phosphorylation and thus promoted fetuin-A degradation through the autophagic pathway, resulting in a decrease in the protein levels of fetuin-A. Moreover, apigenin prevented the formation of the fetuin-A-insulin receptor (IR) complex and thereby rescued the PA-induced impairment of the insulin signaling pathway, as evidenced by increased phosphorylation of IR substrate-1 and Akt, and translocation of glucose transporter 2 from the cytosol to the plasma membrane. Similar results were observed in the liver of HFD-fed mice treated with apigenin. Collectively, our findings revealed that apigenin ameliorates obesity-induced insulin resistance in the liver by targeting fetuin-A.

Liver Fetuin-A at Initiation of Insulin Resistance

Hepatokines (liver secreted proteins with possible distant action) are emerging potential players in insulin resistance in type 2 diabetic patients. Here, we explored the effect of a high-fat diet on the expression of fetuin-A, one of those candidate liver proteins, and its relationship with liver macrophage activation. Mice were fed a normal diet or a high-fat diet for 3 days, known to initiate steatosis and liver insulin resistance. A preventive liver macrophage depletion was obtained by intravenous injection of clodronate-loaded liposomes. The mRNA and protein expression of fetuin-A was evaluated by qPCR, Western blot and immunofluorescence on different insulin-sensitive tissues (liver, adipose tissue, and muscle). Short-term high-fat diet-induced steatosis, liver macrophage activation, and hepatic insulin resistance together with a significantly increased expression of liver AHSG (α2-HS glycoprotein/fetuin-A) mRNA and serum fetuin-A concentration. On immunofluorescence, fetuin-A was mostly expressed in centrilobular hepatocytes. This increase in fetuin-A under high-fat diet was not evidenced in other peripheral insulin-sensitive tissues (skeletal muscle and adipose tissue). The mRNA expression of α2-HS glycoprotein was 800 times higher within the liver compared with the adipose tissue or the muscle. Liver macrophage depletion that significantly ameliorated insulin sensitivity was associated with a significant decrease in α2-HS glycoprotein mRNA expression. In conclusion, this study demonstrated liver fetuin-A overexpression at the initiation of high-fat diet feeding, concurrent with hepatic steatosis and insulin resistance. Targeting liver macrophages in this setting reduced liver α2-HS glycoprotein expression suggesting that fetuin-A acts as an hepatokine with proinsulin resistance effects.

The Correlation between Fetuin-A Levels And Nafld Fibrosis Score (NFS)

Abstract. Fetuin-A is a plasma glycoprotein expressed in the liver. Fatty liver accumulation because changing fetuin-A expression leads to nonalcoholic fatty liver disease (NAFLD). The benefits of serum fetuin-A as a predictor of fibrosis biomarkers in NAFLD patients remain unclear. Non-invasive scoring system predicting fibrosis among patients with NAFLD is the NAFLD fibrosis score (NFS). Objective. This study aims to find the correlation between circulating fetuin-A levels and NFS in NAFLD patients. Methods. Eighty subjects (male, 52; female, 26) followed this cross-sectional study. NAFLD is diagnosed with an abdominal ultrasound. The serum levels of fetuin-A measured by ELISA. NFS is used to identify the probability of fibrosis in subjects. The correlation between Fetuin-A levels and NFS was determined using Pearson correlation tests. A p-value &lt; 0.05 was significant. Results. There was significant difference in fetuin-A levels (p &lt; 0.001) between NAFLD degree I (421.71 pg/mL), NAFLD degree II (494.88 pg/mL), and NAFLD degree III (692 pg/mL). The NFS low probability score in 46 subjects and NFS indeterminate score in 34 subjects. Serum concentrations of fetuin-A correlate significantly with NFS (r = 0.478, p &lt; 0.001). Conclusion. There is a positive correlation between serum levels of fetuin-A and NFS.

Ameliorating effect of 6-week swimming exercise on mice with experimental autoimmune encephalomyelitis (EAE) by reducing fetuin-A and increasing AMPK & NAD⁺ levels in liver tissue.

Objective(s):Multiple sclerosis (MS) is a chronic inflammatory disease affecting sensory and motor function in the central nervous system. Physical activities in the prevention and treatment of such conditions have shown promising results. However, their mechanisms of action have not been fully known yet and need further study. The present study aimed to evaluate the preventive effect of swimming exercise on some liver factors involved in inflammation and MS. Materials and Methods:In this study, experimental autoimmune encephalomyelitis was induced in C57BL/6 mice, and the effect of a 6-week swimming exercise on the levels of fetuin-A, AMP-activated protein kinase (AMPK), and Nicotinamide adenine dinucleotide (NAD+) in their liver tissue was investigated by western blot analysis and NAD+ colorimetric assay.Results:The study showed that EAE induction substantially (3.5 - fold) enhanced the fetuin-A levels and caused a reduction in AMPK and NAD+ amount. This is when doing 6 weeks of swimming exercise reduced fetuin-A to slightly above control. Also, levels of AMPK and NAD+ markedly increased in C57BL/6 mice with EAE.Conclusion:Doing regular exercise may limit the body’s inflammatory responses and reduce the severity of MS by regulating the expression of fetuin-A and increasing AMPK and NAD⁺ levels in liver tissue.

Fetuin-A expression in human umbilical vein endothelial cells and amnion cells of patients with gestational diabetes mellitus.

To elucidate the link between fetuin-A expression in human umbilical vein endothelial cells (HUVECs) and amnion cells (ACs) and clinicopathological changes in patients with gestational diabetes mellitus (GDM) and newborns. This retrospective cohort study included 82 pregnant patients (40 with GDM and 42 controls) between January 2019 and January 2022. The patients underwent a one-hour, 50 gram glucose challenge test (GCT) during the 24-28th weeks of pregnancy. Patients with positive GCTs immediately underwent a 3-hour, 100 gram oral glucose tolerance test. The expression level of fetuin-A in UVECs and ACs was evaluated by immunohistochemistry (IHC) and scored based on IHC staining in randomly selected slides. The IHC staining intensity was evaluated by the number of dots, which reflects the expression level of fetuin-A in both HUVECs and ACs. The GDM group displayed significantly higher fetuin-A expression in both HUVECs (p<0.0001) and ACs (p=0.0001) when compared with the control group. Fetuin-A expression in HUVECs was correlated with fetal macrosomia, neonatal hypoglycemia, and placental weight. However, there was no correlation with fetuin-A expression in ACs. There is a correlation between fetal macrosomia, neonatal hypoglycemia, placental weight, and fetuin-A expression of HUVECs in patients with GDM.

AMP activated kinase negatively regulates hepatic Fetuin-A via p38 MAPK-C/EBPβ/E3 Ubiquitin Ligase Signaling pathway.

Fetuin-A (Fet-A) is a liver-secreted phosphorylated protein, known to impair insulin signaling, which has been shown to be associated with obesity, insulin resistance, and incident diabetes. Fet-A interacts with the insulin-stimulated insulin receptor (IR) and inhibits IR tyrosine kinase activity and glucose uptake. It has been shown that high glucose increases Fet-A expression through the ERK1/2 signaling pathway. However, factors that downregulate Fet-A expression and their potential mechanisms are unclear. We examined the effect of AMP-activated protein kinase (AMPK) on high-glucose induced Fet-A expression in HepG2 cells, Hep3B cells and primary rat hepatocytes. High glucose increased Fet-A and phosphorylated (Ser312) fetuin-A (pFet-A) expression, which are known to impair insulin signaling. AICAR-induced AMPK activation significantly down-regulated high glucose-induced Fet-A expression and secretion of pFet-A while treatment with Compound C (AMPK inhibitor), SB202190 (p38 MAPK inhibitor) or p38 MAPK siRNA transfection prevented AICAR-induced downregulation of Fet-A expression. In addition, activation of p38 MAPK, by anisomycin, decreased the hepatic expression of Fet-A. Further, we our studies have shown that short-term effect of AICAR-treatment on Fet-A expression was mediated by proteosomal degradation, and long-term treatment of AICAR was associated with decrease in hepatic expression of C/EBP beta, an important transcription factor involved in the regulation of Fet-A. Taken together, our studies implicate a critical role for AMPK-p38 MAPK-C/EBPb-ubiquitin-proteosomal axis in the regulation of the expression of hepatic Fet-A.

Molecular and pathobiological involvement of fetuin-A in the pathogenesis of NAFLD.

The liver acts as a manufacturing unit for the production of fetuin-A, which is essential for various physiological characteristics. Scientific research has shown that a moderate upward push in fetuin-A serum levels is associated with a confirmed non-alcoholic fatty liver disease (NAFLD) diagnosis. Fetuin-A modulation is associated with a number of pathophysiological variables that cause liver problems, including insulin receptor signaling deficiencies, adipocyte dysfunction, hepatic inflammation, fibrosis, triacylglycerol production, macrophage invasion, and TLR4 activation. The focus of the present review is on the various molecular pathways, and genetic relevance of mRNA expression of fetuin-A which is correlated with progression of NAFLD. The other major area of exploration in the present review is based on the new targets for the modulation of fetuin-A, like calorie restriction and novel pharmacological agents, such as rosuvastatin, metformin, and pioglitazone which are successfully implicated in the management of various liver-related complications.

Blocking TLR4-NF-κB pathway protects mouse islets from the combinatorial impact of high fat and fetuin-A mediated dysfunction and restores ability for insulin secretion

Lipid mediated pancreatic β-cell dysfunction during Type 2 diabetes is known to be regulated by activation of TLR4 (Toll Like Receptor 4) and NF-κB (Nuclear factor kappa B). Recently we have reported that MIN6 cells (mouse insulinoma cells) secrete fetuin-A on stimulation by palmitate that aggravates β-cell dysfunction, but the mechanism involved in-vivo has not been demonstrated and thus remained unclear. Here we attempted to dissect the role of palmitate and fetuin-A on insulin secretion using high fat diet (HFD) fed mice model. HFD islets showed curtailed insulin secretion after 20 weeks of treatment with activated TLR4-NF-κB pathway. Further treatment of islets with palmitate raised fetuin-A expression by ~2.8 folds and cut down insulin secretion by ~1.4 folds. However, blocking the activity of TLR4, fetuin-A and NF-κB using specific inhibitors or siRNAs not only restored insulin secretion by ~2 folds in standard diet fed mice islets and MIN6 cells but also evoke insulin secretory ability by ~2.3 folds in HFD islets. Altogether this study demonstrated that blocking TLR4, fetuin-A and NF-κB protect pancreatic β-cells from the negative effects of free fatty acid and fetuin-A and restore insulin secretion.

Combination of Pancreastatin inhibitor PSTi8 with metformin inhibits Fetuin-A in type 2 diabetic mice

In the preceding study, we delineated that high-fat diet (HFD) consumption in mice increases the circulatory level of pancreastatin (PST), which additionally enhances the free fatty acid (FFA) concentration in circulation. Consequently, the aggravated FFA activates Fetuin-A, which facilitates hepatic lipid accumulation, insulin resistance (IR), and culminates in type 2 diabetes (T2D). Metformin (Met) is a widely known first-line drug for the treatment of T2D. We previously unveiled PSTi8, an inhibitor of PST, comprising antidiabetic property. Hence, we hypothesized that combination therapy of Met and PSTi8, at reduced therapeutic doses, would mitigate HFD-induced IR by inhibiting hepatic Fetuin-A in mice model of T2D. C57BL/6 mice were fed HFD for 12 weeks, followed by treatment with Met, PSTi8, and its combination for 10 days. Glucose and insulin tolerance tests were conducted. Circulatory levels of PST, Fetuin-A, and lipid markers were determined. Also, the mRNA and protein expression of Fetuin-A was assessed by qPCR, western blotting, and immunofluorescence. Moreover, the energy expenditure was measured by comprehensive laboratory animal monitoring system (CLAMS). Combination therapy displayed improved PST, Fetuin-A, and lipid profile in plasma. We also found reduced hepatic Fetuin-A, which reduced inhibitory phosphorylation of IRS and increased phosphorylation of AKT. Consequently, ameliorated hepatic lipogenesis, gluconeogenesis, and inflammation. Also, combination treatment attenuated Fetuin-A expression, lipid accumulation, and glucose production in palmitate-induced HepG2 cells. Altogether current study promulgates the beneficial effect of combination therapy of Met and PSTi8 (comparable to alone higher therapeutic doses) to ameliorate Fetuin-A activation, hepatic lipid accumulation, insulin resistance, and associated progressive pathophysiological alterations in T2D.

Serum Fetuin-A and Insulin Levels in Classic Congenital Adrenal Hyperplasia.

Androgens play a pivotal role in non-reproductive organs such as the kidney, heart, liver, and pancreas. As androgen receptors are expressed in pancreatic and liver cells, excess testosterone can result in hypersecretion of insulin and fetuin-A, a protein produced in the liver. The expression of fetuin-A, a natural inhibitor of tyrosine kinase activity in muscle and liver, leads to insulin resistance. In addition, insulin and fetuin-A levels are thought to be affected by drugs such as glucocorticoids (GCs) and fludrocortisone. However, whether fetuin-A and insulin levels are affected by androgens and GCs in patients with classic congenital adrenal hyperplasia (CAH) is unknown. This cross-sectional study included 56 CAH patients and 70 controls. Analyses were stratified by sex and prepubertal/pubertal status to control for potential changes in serum metabolic/inflammatory markers associated with the production of sex steroids. Fasting blood glucose, insulin, triglyceride, total cholesterol, high density lipoprotein-cholesterol, aspartate aminotransferase, alanine aminotransferase, fetuin-A, and high-sensitivity C-reactive protein (hs-CRP) levels were measured in blood samples. In addition, 17α-hydroxyprogesterone, androstenedione, total testosterone, free testosterone, and dehydroepiandrosterone sulfate levels were measured before medication was administered. Insulin and fetuin-A levels were significantly higher in CAH patients than in controls. The unfavourably high levels of these substances exhibited a positive correlation with total and free testosterone. Regression analysis revealed that fetuin-A and free testosterone were the only independent predictors of the insulin level, while insulin and free testosterone levels significantly predicted the fetuin-A level (R2=42.7% and 59.8%). Differences were also observed in triglyceride and hs-CRP levels between the pubertal and prepubertal groups. We conclude that serum fetuin-A and insulin levels may be associated with androgens in CAH patients.

Roles Of EAAT1, DHFR, And Fetuin-A In The Pathogenesis, Progression And Prognosis Of Chondrosarcoma.

AimsChondrosarcoma (CS) is a high-morbidity, relatively common bone malignancy without well-established biomarkers. The proteins EAAT1, DHFR, and fetuin-A have been investigated in many cancers, but their specific relationship to CS has not been reported. The present study examined EAAT1, DHFR, and fetuin-A expression in CS and the clinicopathological significance of these proteins in CS pathogenesis, progression, and prognosis.MethodsEAAT1, DHFR, and fetuin-A protein levels in 80 CS and 25 chondroma specimens were measured by immunohistochemistry and related to histological and clinical factors with chi-squared tests. Following univariate survival analysis, ROC curves calculation, and multivariate analysis.ResultsEAAT1, DHFR, and fetuin-A expression levels were significantly higher in the CS group than in the chondroma group (p < 0.05). Their immunopositivity rates were significantly greater in tissues with moderate or poor tumor differentiation, AJCC stage III or IV, Enneking stage II or III, and metastasis (p<0.05 or p<0.01 or p<0.001). Kaplan–Meier survival analysis showed significantly shorter survival in patients with moderately or poorly differentiated tumors, AJCC stage III or IV CS, Enneking stage II or III CS, metastasis, invasion, or EAAT1, DHFR, and fetuin-A immunopositivity (p < 0.05 or p < 0.001). Cox regression analysis showed that moderate or poor tumor differentiation, AJCC stage III or IV, Enneking stage II or III, metastasis, invasion, and EAAT1, DHFR, or fetuin-A immunopositivity correlated negatively with postoperative survival and positively with mortality (p < 0.05). The AUCs for EAAT1, DHFR, and fetuin-A were 0.654 (95% CI: 0.532–0.776, p = 0.025), 0.638 (95% CI: 0.519–0.756, p = 0.039), and 0.670 (95% CI: 0.556–0.784, p = 0.011), respectively.ConclusionEAAT1, DHFR, and fetuin-A may be important biomarkers of the pathogenesis and progression of CS and predictors of its prognosis.

Pterocarpus santalinus ameliorates streptozotocin-induced diabetes mellitus via anti-inflammatory pathways and enhancement of insulin function.

Objective(s):Morbidity and mortality due to diabetes mellitus (DM) result in exorbitant psycho-economical costs, so there is a strong need to create new strategies and drugs for controlling DM. The aim of the current study was to investigate the anti-diabetic effect of the aqueous extract of Pterocarpus santalinus on streptozotocin (STZ)-induced DM as compared to glustin. Materials and Methods:Thirty male rats were divided into five groups of six rats each as follows: control; the second group, received the aqueous plant extract (250 mg/kg) orally and daily for three weeks; the third group, was intraperitoneally injected with a single dose of 65 mg/kg of STZ and sacrificed after four weeks; the fourth and fifth groups, were injected with STZ, then after one week these were treated orally with either plant extract or with 3 mg/kg of glustin for three weeks, then sacrificed. Results:HPLC analysis of the plant aqueous extract showed that it contains many polyphenols and flavonoids. Treatment with STZ resulted in significant reductions in body weight, insulin level, and the expression of Fetuin-A and IRS-1. It also caused significant elevations in glucose, HOMA-IR, glycated hemoglobin, urea, and the expression of JNK and SIRT-1. STZ also caused an extensive β-cell degranulation and decreased cellular density. The aqueous extract of red sandalwood was able to abrogate the deleterious effects caused by STZ and improved the histological architecture of pancreasConclusion:The aqueous extract of P. santalinus ameliorates diabetes mellitus via anti-inflammatory pathways and enhancement of insulin function.

Protectin DX ameliorates palmitate‐induced hepatic insulin resistance through AMPK/SIRT1‐mediated modulation of fetuin‐A and SeP expression

The role as well as the molecular mechanisms of protectin DX (PDX) in the prevention of hepatic insulin resistance, a hallmark of type 2 diabetes, remains unknown. Therefore, the present study was designed to explore the direct impact of PDX on insulin resistance and to investigate the expression of fetuin-A and selenoprotein P (SeP), hepatokines that are involved in insulin signalling, in hepatocytes. Human serum levels of PDX as well as fetuin-A and SeP were determined by high-performance liquid chromatography (HPLC). Human primary hepatocytes were treated with palmitate and PDX. NF-κB phosphorylation as well as expression of insulin signalling associated genes and hepatokines were determined by Western blotting analysis. FOXO1 binding levels were measured by quantitative real-time PCR. Selected genes from candidate pathways were evaluated by small interfering (si) RNA-mediated gene suppression. Serum PDX levels were significantly (P<0.05) downregulated, whereas serum fetuin-A and SeP levels were increased (P<0.05) in obese subjects compared with healthy subjects. In in vitro experiments, PDX treatment increased AMP-activated protein kinase (AMPK) phosphorylation and SIRT1 expression and attenuated palmitate-induced fetuin-A and SeP expression and insulin resistance in hepatocytes. AMPK or SIRT1 siRNA mitigated the suppressive effects of PDX on palmitate-induced fetuin-A through NF-κB and SeP expression linked to FOXO1 and insulin resistance. Recombinant fetuin-A and SeP reversed the suppressive effects of fetuin-A and SeP expression on palmitate-mediated impairment of insulin signalling. The current finding provides novel insight into the underlying mechanism linking hepatokines to the pathogenesis of hepatic insulin resistance.

Incremental effects of diabetes mellitus and chronic kidney disease in medial arterial calcification: Synergistic pathways for peripheral artery disease progression.

Diabetes mellitus (DM) and chronic kidney disease (CKD) separately are known to facilitate the progression of medial arterial calcification (MAC) in patients with symptomatic peripheral artery disease (PAD), but their combined effect on MAC and associated mediators of calcification is not well studied. The association of MAC and calcification inducer bone morphogenetic protein (BMP-2) and inhibitor fetuin-A, with PAD, is well known. Our aim was to investigate the association of MAC with alterations in BMP-2 and fetuin-A protein expression in patients with PAD with DM and/or CKD. Peripheral artery plaques (50) collected during directional atherectomy from symptomatic patients with PAD were evaluated, grouped into no-DM/no-CKD (n = 14), DM alone (n = 10), CKD alone (n = 12), and DM+CKD (n = 14). MAC density was evaluated using hematoxylin and eosin, and alizarin red stain. Analysis of inflammation, neovascularization, BMP-2 and fetuin-A protein density was performed by immunohistochemistry. MAC density, inflammation grade and neovessel content were significantly higher in DM+CKD versus no-DM/no-CKD and CKD (p < 0.01). BMP-2 protein density was significantly higher in DM+CKD versus all other groups (p < 0.01), whereas fetuin-A protein density was significantly lower in DM+CKD versus all other groups (p < 0.001). The combined presence of DM+CKD may be associated with MAC severity in PAD plaques more so than DM or CKD alone, as illustrated in this study, where levels of calcification mediators BMP-2 and fetuin-A protein were related most robustly to DM+CKD. Further understanding of mechanisms involved in mediating calcification and their association with DM and CKD may be useful in improving management and developing therapeutic interventions.

Hepatic upregulation of fetuin-A mediates acetaminophen-induced liver injury through activation of TLR4 in mice

Acetaminophen (APAP)-induced liver injury (AILI) is initiated by the generation of a reactive metabolite and ultimately leads to hepatocyte necrosis. Necrotic cells secrete damage-associated molecular patterns that activate hepatic nonparenchymal cells and induce an inflammatory response. Fetuin-A is a hepatokine with reported involvement in low-grade inflammation in many diseases, due to acting as an endogenous ligand for TLR4. However, little is known about the role of fetuin-A in AILI. In this study, we showed that fetuin-A is involved in the aggravation of hepatotoxicity during the initial phase of AILI progression. Treatment with APAP increased the expression and serum levels of fetuin-A in mice. Fetuin-A upregulated transcription of pro-inflammatory cytokines and chemokines through activation of TLR4 and also increased monocyte infiltration into the liver, leading to necroinflammatory reactions in AILI. However, these reactions were attenuated with the silencing of fetuin-A using adenoviral shRNA. As a result, mice with silenced fetuin-A exhibited less centrilobular necrosis and liver injury compared to controls in response to APAP. In conclusion, our results suggest that fetuin-A is an important hepatokine that mediates the hepatotoxicity of APAP through production of chemokines and thus regulates the infiltration of monocytes into the liver, a critical event in the inflammatory response during the initial phase of AILI. Our results indicate that a strategy based on the antagonism of fetuin-A may be a novel therapeutic approach to the treatment of acetaminophen-induced acute liver failure.

SAT-160 Fetuin-a Secreted From Pancreatic β-cells Plays Significant Role In Macrophage Accumulation And Inflammation In The Islets During Hyperlipidemic Condition

Inflammation in the pancreatic islets by means of increased macrophage migration and elevated levels of pro-inflammatory cytokines in the circulating serum occurs during Type 2 Diabetes. Another mechanism underlying increase in inflammation is polarization of macrophages from anti-inflammatory M2 to pro-inflammatory M1 form. Whether such changes occur in the infiltrating macrophages in the islets and what were the factors leading to these changes arte yet unknown. Fetuin-A, a glycoprotein known to be secreted from liver and adipocytes has also been found to be secreted from pancreatic β-cells by our group recently. Role of fetuin-A in macrophage polarisation has been worked upon but still more work is yet to be done. Our focus of interest was whether the β-cell derived fetuin-A has any role in polarisation of macrophages migrating to the islets leading to increase in inflammation. For in vivo model we used high fat diet mice model and for in vitro studies we used MIN6 pancreatic β cell line and RAW 264.7 murine macrophage cell line. In the in vivo mice model immunohistochemistry studies revealed increase in number of M1 macrophages in the pancreatic islets and fetuin-A secretion in comparison to the control standard diet fed mice (CD11c, arginase, F4/80). Also there was decrease in islet mass, specifically in number of β-cells. Fetuin-A KD mice using vivo morpholino showed decrease in infiltrating M1 macrophages in the islets as well improved β-cell survival. For replicating hyperlipidemic condion in vitro we treated the MIN6 cells with various doses of palmitate (0, 0.25, 0.50 and 0.75 mM) and assessed the increase in number of infiltrating RAW 264.7 macrophages (4 folds) in a boyden chamber system along with increasing level of fetuin-A (3 folds) in the media as determined by ELISA. Next the effect of this β-cell derived fetuin-A was observed upon macrophage polarisation. Originally RAW264.7 is anti-inflammatory M2 type. The cells were treated with fetuin-A secreted from β-cells, palmitate alone and LPS plus TNFα (positive control), while a set of macrophages were left untreated as negative control. The cells were collected and subjected to qualitative PCR for identifying the expression of M1 and M2 markers like CD11c, arginase, F4/80 and it was found that the pro-inflammatory markers increased in fetuin-A treated RAW 264.7 cells in similar levels like that of LPS+TNFα levels. These results indicated possible role of β-cell derived fetuin-A in macrophage polarisation in the islets. Another important point was that β-cells also express MCP1 another chemoattractant. Blocking of MCP1 by si-RNA decreased macrophage migration a little but expression of fetuin-A was enough for significant number of macrophages to migrate, however blocking fetuin-A by si-RNA in MIN6 cells decreased the number of migrating macrophages significantly.

Fetuin-A levels are increased in the adipose tissue of diabetic obese humans but not in circulation

BackgroundThe hepatokine fetuin-A is linked to obesity and type 2 diabetes, but its presence and expression in adipose tissue remain unclear. In this study, we aimed to assess the circulating levels of fetuin-A and its expression in subcutaneous adipose tissue (SAT) from diabetic and non-diabetic obese subjects and their modulation by exercise.MethodsSAT and blood were obtained from adults obese (diabetic, n=118 and non-diabetic, n=166) before and after a 3-month exercise program (diabetic, n=40 and non-diabetic, n=36, respectively). Plasma fetuin-A was assayed using ELISA. The presence and expression of fetuin-A in SAT, peripheral blood mononuclear cells (PBMCs) and cell lines (3T3-L1, THP-1, HepG2, RAW 264.7) were analysed using confocal microscopy, immunoblotting and qRT-PCR.ResultsPlasma fetuin-A level did not significantly differ between diabetic and non-diabetic obese subjects. However, when the non-diabetic group was divided into metabolically healthy and unhealthy phenotypes, significantly higher fetuin-A level was observed in the unhealthy sub-group. Circulating fetuin-A was mainly associated with glycaemic markers. In SAT, fetuin-A protein level was significantly higher in the diabetic obese subjects but its mRNA was not detected. Similarly, fetuin-A protein was detected in PBMCs, but its mRNA was not. In line with this, the use of various cell lines and culture media indicated that the presence of fetuin-A in SAT and PBMCs was due to its uptake from circulation rather than its endogenous expression. Finally, physical exercise decreased fetuin-A levels in both plasma and SAT in both groups.ConclusionsFetuin-A levels increased in association with diabetes in SAT but not in circulation in the obese subjects. Moreover, physical exercise decreased fetuin-A level. Fetuin-A potentially acts as a hepatokine taken up by other tissues, such as adipose tissue.

Changes in Liver Gene Expression and Plasma Concentration of Rbp4, Fetuin-A, and Fgf21 in Sprague-Dawley Rats Subjected to Different Dietary Interventions and Bariatric Surgery.

Purpose To study the effect of duodenal-jejunal omega switch (DJOS) in combination with different dietary patterns on the retinol-binding protein (RBP4), fetuin-A, and fibroblast growth factor 21 (FGF21) plasma levels and their hepatic gene expressions in rats. Methods A high-fat diet (HF) was given to 28 rats and 28 more were fed with a control diet (CD) for 2 months. After that, half of each group underwent either DJOS or SHAM surgery. For the next 2 months, half of the animals in each operation group were kept on the same diet as before and half of them had the diet changed. After 16 weeks of the experiment RBP4, fetuin-A, and FGF21 plasma levels as well as liver Rbp4, Ahsg, and Fgf21 gene expressions were measured. Results DJOS had a reductive impact on plasma levels of RBP4, fetuin-A, and FGF21 and Rbp4, Ahsg, and Fgf21 relative gene expression in the liver when compared to SHAM. The HF/HF group expressed significantly higher RBP4 and fetuin-A plasma levels in comparison to the control. The HF diet used before and/or after surgery led to upregulation of Rbp4, Ahsg, and Fgf21 relative gene expression. The lowest levels of analyzed parameters were observed in the CD/CD group. Conclusions The efficiency of DJOS surgery, measured by hepatokines' plasma levels and their gene expressions in the liver, depends on the type of diet applied before and after surgery. Manipulation of dietary patterns can lead to marked improvements in metabolic profile after DJOS surgery.