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Alcohol consumption and obesity are known risk factors of steatohepatitis. Here, we report that the deficiency of CRAMP (cathelicidin-related antimicrobial peptide-gene name: Camp ) is protective against a high-fat diet (HFD) plus acute alcohol (HFDE)-induced liver injury. HFDE markedly induced liver injury and steatosis in WT mice, which were attenuated in Camp -/- mice. Neutrophil infiltration was lessened in the liver of Camp -/- mice. HFDE feeding dramatically increased epididymal white adipose tissue (eWAT) mass and induced adipocyte hypertrophy in WT mice, whereas these effects were attenuated by the deletion of Camp . Furthermore, Camp -/- mice had significantly increased eWAT lipolysis, evidenced by up-regulated expression of lipolytic enzymes, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). The depletion of Camp also increased uncoupling protein 1 (UCP1)-dependent thermogenesis in the brown adipose tissue (BAT) of mice. HFDE fed Camp -/- mice had elevated protein levels of fibroblast growth factor 21 (FGF21) in the eWAT, with an increased adiponectin production, which had been shown to alleviate hepatic fat deposition and inflammation. Collectively, we have demonstrated that Camp -/- mice are protected against HFD plus alcohol-induced liver injury and steatosis through FGF21/adiponectin regulation. Targeting CRAMP could be an effective approach for prevention/treatment of high-fat diet plus alcohol consumption-induced steatohepatitis.

Background and Aims: Cholestatic liver disease is characterized by gut dysbiosis and excessive toxic hepatic bile acids (BAs). Modification of gut microbiota and repression of BA synthesis are potential strategies for the treatment of cholestatic liver disease. The purpose of this study was to examine the effects and to understand the mechanisms of the probiotic Lactobacillus rhamnosus GG (LGG) on hepatic BA synthesis, liver injury, and fibrosis in bile duct ligation (BDL) and multidrug resistance protein 2 knockout (Mdr2 -/- ) mice., Approach and Results: Global and intestine-specific farnesoid X receptor (FXR) inhibitors were used to dissect the role of FXR. LGG treatment significantly attenuated liver inflammation, injury, and fibrosis with a significant reduction of hepatic BAs in BDL mice. Hepatic concentration of taurine-β-muricholic acid (T-βMCA), an FXR antagonist, was markedly increased in BDL mice and reduced in LGG-treated mice, while chenodeoxycholic acid, an FXR agonist, was decreased in BDL mice and normalized in LGG-treated mice. LGG treatment significantly increased the expression of serum and ileum fibroblast growth factor 15 (FGF-15) and subsequently reduced hepatic cholesterol 7α-hydroxylase and BA synthesis in BDL and Mdr2 -/- mice. At the molecular level, these changes were reversed by global and intestine-specific FXR inhibitors in BDL mice. In addition, LGG treatment altered gut microbiota, which was associated with increased BA deconjugation and increased fecal and urine BA excretion in both BDL and Mdr2 -/- mice. In vitro studies showed that LGG suppressed the inhibitory effect of T-βMCA on FXR and FGF-19 expression in Caco-2 cells., Conclusion: LGG supplementation decreases hepatic BA by increasing intestinal FXR-FGF-15 signaling pathway-mediated suppression of BA de novo synthesis and enhances BA excretion, which prevents excessive BA-induced liver injury and fibrosis in mice., (© 2019 The Authors. Hepatology published by Wiley Periodicals, Inc., on behalf of American Association for the Study of Liver Diseases.)

High-fat/high-fructose diet plus intermittent hypoxia exposure (HFDIH) causes metabolic disorders such as insulin resistance, obesity, nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes. The purpose of this study is to examine the effects and understand the mechanism of action of Lactobacillus rhamnosus GG culture supernatant (LGGs) on HFDIH-induced metabolic dysfunction. Mice were fed high-fat:high-fructose diet for 15 weeks. After 3 weeks of feeding, the mice were exposed to chronic intermittent hypoxia for the next 12 weeks (HFDIH), and LGGs was supplemented over the entire experiment. HFDIH exposure significantly led to metabolic disorders. LGGs treatment showed significant improvements in indices of metabolic disorders including fat mass, energy expenditure, glucose intolerance, insulin resistance, increased hepatic steatosis and liver injury. HFDIH mice markedly increased adipose inflammation and adipocyte size, and reduced circulating adiponectin, which was restored by LGGs treatment. LGGs treatment increased hepatic FGF21 mRNA expression and circulating FGF21 protein levels, which were associated with increased hepatic PPARα expression and fecal butyrate concentration. In addition, HFDIH-induced hepatic fat accumulation and apoptosis were significantly reduced by LGGs supplementation. In summary, LGGs treatment increased energy expenditure and insulin sensitivity and prevented metabolic abnormalities in HFDIH mice, and this is associated with the FGF21-adiponectin signaling pathway. LGGs may be a potential prevention/treatment strategy in subjects with the metabolic syndrome., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objectives: High fructose feeding changes fibroblast growth factor 21 (FGF21) regulation. Lactobacillus rhamnosus GG (LGG) supplementation reduces fructose-induced non-alcoholic fatty liver disease (NAFLD). The aim of this study was to determine the role of FGF21 and underlying mechanisms in the protective effects of LGG., Methods: FGF21 knockout (KO) mice and C57BL/6 wild type (WT) mice were fed 30% fructose for 12 weeks. LGG was administered to the mice in the last 4 weeks during fructose feeding. FGF21-adiponectin (ADPN)-mediated hepatic lipogenesis and inflammation were investigated., Results: FGF21 expression was robustly increased after 5-weeks of feeding and significantly decreased after 12-weeks of feeding in fructose-induced NAFLD mice. LGG administration reversed the depressed FGF21 expression, increased adipose production of ADPN, and reduced hepatic fat accumulation and inflammation in the WT mice but not in the KO mice. Hepatic nuclear carbohydrate responsive-element binding protein (ChREBP) was increased by fructose and reduced by LGG, resulting in a reduction in the expression of lipogenic genes. The methylated form of protein phosphatase 2A (PP2A) C, which dephosphorylates and activates ChREBP, was upregulated by fructose and normalized by LGG. Leucine carboxyl methyltransferase-1, which methylates PP2AC, was also increased by fructose and decreased by LGG. However, those beneficial effects of LGG were blunted in the KO mice. Hepatic dihydrosphingosine-1-phosphate, which inhibits PP2A, was markedly increased by LGG in the WT mice but attenuated in the KO mice. LGG decreased adipose hypertrophy and increased serum levels of ADPN, which regulates sphingosine metabolism. This beneficial effect was decreased in the KO mice., Conclusion: LGG administration increases hepatic FGF21 expression and serum ADPN concentration, resulting in a reduced ChREBP activation through dihydrosphingosine-1-phosphate-mediated PP2A deactivation, and subsequently reversed fructose-induced NAFLD. Thus, our data suggest that FGF21 is required for the beneficial effects of LGG in reversal of fructose-induced NAFLD., (Copyright © 2019 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Excess alcohol consumption can lead to alcoholic liver disease. Fibroblast growth factor 21 (FGF21) is a metabolic regulator with multiple physiologic functions. Previous study demonstrated that FGF21 deficiency exacerbated alcohol-induced liver injury and exogenous FGF21 administration protected liver from chronic alcohol-induced injury. In this study, we aimed to explore the role of FGF21 in alcohol metabolism in mice. FGF21 knockout (KO) mice and the wild type(WT) control mice were divided into two groups and fasted for 24 h followed by a bonus of alcohol treatment at a dose of 5 g/kg body weight via gavage. Serum alcohol concentration was measured after gavage at 0.5, 2, 3, 4 and 6 h, respectively. At the end, gastric and liver tissues were collected. Serum alcohol concentration of KO mice was significantly lower than that of WT at 0.5 h after alcohol expose. There were no significant differences in alcohol dehydrogenase (ADH) activity and aldehyde dehydrogenase 2 (ALDH2) activity in gastric and liver tissues between WT and the KO mice. However, gastric emptying time of KO mice was much longer than that of WT mice. In addition, the intestinal permeability and serum GLP-1 level of KO mice were significantly higher than that of WT mice. These results suggest that FGF21 deficiency slow gastric emptying rate and indirectly influence initial alcohol metabolism in mice exposed to acute alcohol. Our findings provide additional information for understanding the gastrointestinal mechanism of alcoholic liver disease and other alcohol use disorders., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Fibroblast growth factor 21 (FGF21) is a hepatokine that regulates glucose and lipid metabolism in the liver. We sought to determine the role of FGF21 in hepatic steatosis in mice exposed to chronic alcohol treatment and to discern underlying mechanisms. Male FGF21 knockout (FGF21 KO) and control (WT) mice were divided into groups that were fed either the Lieber DeCarli diet containing 5% alcohol or an isocaloric (control) diet for 4 weeks. One group of WT mice exposed to alcohol received recombinant human FGF21 (rhFGF21) in the last 5 days. Liver steatosis and inflammation were assessed. Primary mouse hepatocytes and AML-12 cells were incubated with metformin or rhFGF21. Hepatic genes and the products involved in in situ lipogenesis and fatty acid β-oxidation were analyzed. Alcohol exposure increased circulating levels and hepatic expression of FGF21. FGF21 depletion exacerbated alcohol-induced hepatic steatosis and liver injury, which was associated with increased activation of genes involved in lipogenesis mediated by SREBP1c and decreased expression of genes involved in fatty acid β-oxidation mediated by PGC1α. rhFGF21 administration reduced alcohol-induced hepatic steatosis and inflammation in WT mice. These results reveal that alcohol-induced FGF21 expression is a hepatic adaptive response to lipid dysregulation. Targeting FGF21 signaling could be a novel treatment approach for alcoholic steatohepatitis.

The lipid lowering medication, fenofibrate (FF), is a peroxisome proliferator-activated receptor-alpha (PPARα) agonist, possessing beneficial effects for type 2 diabetic nephropathy (DN). We investigated whether FF can prevent the development of type 1 DN, and the underlying mechanisms. Diabetes was induced by a single intraperitoneal injection of streptozotocin in C57BL/6J mice. Mice were treated with oral gavage of FF at 100mg/kg every other day for 3 and 6 months. Diabetes-induced renal oxidative stress, inflammation, apoptosis, lipid and collagen accumulation, and renal dysfunction were accompanied by significant decrease in PI3K, Akt, and GSK-3β phosphorylation as well as an increase in the nuclear accumulation of Fyn [a negative regulator of nuclear factor (erythroid-derived 2)-like 2 (Nrf2)]. All these adverse effects were significantly attenuated by FF treatment. FF also significantly increased fibroblast growth factor 21 (FGF21) expression and enhanced Nrf2 function in diabetic and non-diabetic kidneys. Moreover, FF-induced amelioration of diabetic renal damage, including the stimulation of PI3K/Akt/GSK-3β/Fyn pathway and the enhancement of Nrf2 function were abolished in FGF21-null mice, confirming the critical role of FGF21 in FF-induced renal protection. These results suggest for the first time that FF prevents the development of DN via up-regulating FGF21 and stimulating PI3K/Akt/GSK-3β/Fyn-mediated activation of the Nrf2 pathway., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Fenofibrate (FF), as a peroxisome-proliferator-activated receptor α (PPARα) agonist, has been used clinically for decades to lower lipid levels. In the present study, we examined whether FF can be repurposed to prevent the pathogenesi of the heart in Type 1 diabetes and to describe the underlying mechanism of its action. Streptozotocin (STZ)-induced diabetic mice and their age-matched control mice were treated with vehicle or FF by gavage every other day for 3 or 6 months. FF prevented diabetes-induced cardiac dysfunction (e.g. decreased ejection fraction and hypertrophy), inflammation and remodelling. FF also increased cardiac expression of fibroblast growth factor 21 (FGF21) and sirtuin 1 (Sirt1) in non-diabetic and diabetic conditions. Deletion of FGF21 gene (FGF21-KO) worsened diabetes-induced pathogenic effects in the heart. FF treatment prevented heart deterioration in the wild-type diabetic mice, but could not do so in the FGF21-KO diabetic mice although the systemic lipid profile was lowered in both wild-type and FGF21-KO diabetic mice. Mechanistically, FF treatment prevented diabetes-impaired autophagy, reflected by increased microtubule-associated protein 1A/1B-light chain 3, in the wild-type diabetic mice but not in the FGF21-KO diabetic mice. Studies with H9C2 cells in vitro demonstrated that exposure to high glucose (HG) significantly increased inflammatory response, oxidative stress and pro-fibrotic response and also significantly inhibited autophagy. These effects of HG were prevented by FF treatment. Inhibition of either autophagy by 3-methyladenine (3MA) or Sirt1 by sirtinol (SI) abolished FF's prevention of HG-induced effects. These results suggested that FF could prevent Type 1 diabetes-induced pathological and functional abnormalities of the heart by increasing FGF21 that may up-regulate Sirt1-mediated autophagy., (© 2016 Authors; published by Portland Press Limited.)

Alcohol consumption leads to adipose tissue lipoatrophy and mobilization of FFAs, which contributes to hepatic fat accumulation in alcoholic liver disease. This study aimed to investigate the role of fibroblast growth factor (FGF)21, a metabolic regulator, in the regulation of chronic-binge alcohol-induced adipose tissue lipolysis. FGF21 KO mice were subjected to chronic-binge alcohol exposure, and epididymal white adipose tissue lipolysis and liver steatosis were investigated. Alcohol exposure caused adipose intracellular cAMP elevation and activation of lipolytic enzymes, leading to FFA mobilization in both WT and FGF21 KO mice. However, alcohol-induced systemic elevation of catecholamine, which is known to be a major player in adipose lipolysis by binding to the β-adrenergic receptor, was markedly inhibited in KO mice. Supplementation with recombinant human FGF21 to alcohol-exposed FGF21 KO mice resulted in an increase in fat loss in parallel with an increase of circulating norepinephrine concentration. Furthermore, alcohol consumption-induced fatty liver was blunted in the KO mice, indicating an inhibition of fatty acid reverse transport from adipose to the liver in the KO mice. Taken together, our studies demonstrate that FGF21 KO mice are protected from alcohol-induced adipose tissue excess-lipolysis through a mechanism involving systemic catecholamine release.

Aims/hypothesis: This study investigated fibroblast growth factor 21 (FGF21)-mediated cardiac protection against apoptosis caused by diabetic lipotoxicity and explored the protective mechanisms involved., Methods: Cardiac Fgf21 mRNA expression was examined in a diabetic mouse model using real-time PCR. After pre-incubation of palmitate-treated cardiac H9c2 cells and primary cardiomyocytes with FGF21 for 15 h, apoptosis and Fgf21-induced cell-survival signalling were investigated using small interfering (si)RNA and/or pharmacological inhibitors. We also examined the cardiac apoptotic signalling and structural and functional indices in wild-type and Fgf21-knockout (Fgf21-KO) diabetic mice., Results: In a mouse model of type 1 diabetes, cardiac Fgf21 expression was upregulated about 40-fold at 2 months and 3-1.5-fold at 4 and 6 months after diabetes. FGF21 significantly reduced palmitate-induced cardiac apoptosis. Mechanistically, palmitate downregulated, but FGF21 upregulated, phosphorylation levels of extracellular signal-regulated kinase (ERK)1/2, mitogen-activated protein kinase 14 (p38 MAPK) and AMP-activated protein kinase (AMPK). Inhibition of each kinase with its inhibitor and/or siRNA revealed that FGF21 prevents palmitate-induced cardiac apoptosis via upregulating the ERK1/2-dependent p38 MAPK-AMPK signalling pathway. In vivo administration of FGF21, but not FGF21 plus ERK1/2 inhibitor, to diabetic or fatty-acid-infused mice significantly prevented cardiac apoptosis and reduced inactivation of ERK1/2, p38 MAPK and AMPK and prevented cardiac remodelling and dysfunction. The Fgf21-KO mice were more susceptible to diabetes-induced cardiac apoptosis, and this could be prevented by administration of FGF21. Deletion of Fgf21 did not further exacerbate cardiac dysfunction., Conclusions/interpretation: These results demonstrate that FGF21 prevents lipid- or diabetes-induced cardiac apoptosis by activating the ERK1/2-p38 MAPK-AMPK pathway. FGF21 may be a therapeutic target for the treatment of diabetes-related cardiac damage.

Fibroblast growth factor 21 (FGF21) plays an important role in energy homoeostasis. The unaddressed question of FGF21's effect on the development and progression of diabetic cardiomyopathy (DCM) is investigated here with FGF21 knockout (FGF21KO) diabetic mice. Type 1 diabetes was induced in both FGF21KO and C57BL/6J wild-type (WT) mice via streptozotocin. At 1, 2 and 4 months after diabetes onset, the plasma FGF21 levels were significantly decreased in WT diabetic mice compared to controls. There was no significant difference between FGF21KO and WT diabetic mice in blood glucose and triglyceride levels. FGF21KO diabetic mice showed earlier and more severe cardiac dysfunction, remodelling and oxidative stress, as well as greater increase in cardiac lipid accumulation than WT diabetic mice. Western blots showed that increased cardiac lipid accumulation was accompanied by further increases in the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and its target protein CD36, along with decreases in the phosphorylation of AMP-activated protein kinase and the expression of hexokinase II and peroxisome proliferator-activated receptor gamma co-activator 1α in the heart of FGF21KO diabetic mice compared to WT diabetic mice. Our results demonstrate that FGF21 deletion-aggravated cardiac lipid accumulation is likely mediated by cardiac Nrf2-driven CD36 up-regulation, which may contribute to the increased cardiac oxidative stress and remodelling, and the eventual development of DCM. These findings suggest that FGF21 may be a therapeutic target for the treatment of DCM., (© 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Fibroblast growth factor 21 (FGF21) is an important regulator in glucose and lipid metabolism, and has been considered as a potential therapy for diabetes. The effect of FGF21 on the development and progression of diabetes-induced pathogenic changes in the aorta has not currently been addressed. To characterize these effects, type 1 diabetes was induced in both FGF21 knockout (FGF21KO) and C57BL/6 J wild type (WT) mice via multiple-dose streptozotocin injection. FGF21KO diabetic mice showed both earlier and more severe aortic remodeling indicated by aortic thickening, collagen accumulation and fibrotic mediator connective tissue growth factor expression. This was accompanied by significant aortic cell apoptosis than in WT diabetic mice. Further investigation found that FGF21 deletion exacerbated aortic inflammation and oxidative stress reflected by elevated expression of tumor necrosis factor α and transforming growth factor β, and the accumulation of 3-nitrotyrocine and 4-Hydroxynonenal. FGF21 administration can reverse the pathologic changes in FGF21KO diabetic mice. These findings demonstrate that FGF21 deletion aggravates aortic remodeling and cell death probably via exacerbation of aortic inflammation and oxidative stress. This marks FGF21 as a potential therapy for the treatment of aortic damage due to diabetes.

Fibroblast growth factor 21 (FGF21) is a metabolic regulator that is required for normal spermatogenesis and protects against diabetes-induced germ cell apoptosis. Here, we tried to define whether diabetes-induced germ cell apoptosis that is predominantly due to increased oxidative stress was associated with impaired glucose and fatty acid metabolism, by examining the effects of Fgf21 gene knockout (FGF21-KO) or FGF21 treatment on the glucose and fatty acid metabolic pathways in streptozotocin-induced diabetic mice. Western blottings revealed that protein kinase B (AKT)-mediated glucose signaling was down-regulated in diabetic testes and further decreased in FGF21-KO diabetic group both 10 days and 2 months after diabetes onset, reflected by reduced glycogen synthase (GS) kinase (GSK)-3β phosphorylation and increased GS phosphorylation. Deletion of the Fgf21 gene also inactivated fatty acid metabolism-related factors, AMP-activated protein kinase (AMPK), sirtuin 1 (Sirt1), and peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), along with exacerbating diabetes-induced testicular oxidative stress and damage. Treatment with recombinant FGF21 partially prevented these diabetic effects. In FGF21-KO nondiabetic mice, testicular AMPK/Sirt1/PGC-1α signaling was down-regulated and AKT1 and murine double minute 2 were inactivated along with the increased p53 expression but not AKT2, GSK-3β, and GS. These results suggest that the role of FGF21 in maintaining spermatogenesis is associated with its activation of AKT1 and inhibition of p53. Deletion of the Fgf21gene significantly exacerbates diabetes-induced down-regulation of testicular AKT/GSK-3β/GS and AMPK/Sirt1/PGC-1α pathways and testicular oxidative stress and cell apoptosis.

Fibroblast growth factor 21 (FGF21) is a novel member identified and was reported to express predominantly in pancreas, liver and adipose tissue, and relatively less in other organs, such as the testis. However, the role of FGF21 in the testis has never been addressed. The present study examined FGF21 expression at mRNA level by real-time RT-PCR assay in the testis of fasting and non-fasting mice or mice with type 1 diabetes that was induced with streptozotocin. We also examined the effect of Fgf21 gene deletion or supplementation of the exogenous FGF21 on the testicular apoptotic cell death spontaneously or induced by type 1 diabetes in FGF21 knockout (FGF21-KO) mice. Deletion of Fgf21 gene does not affect testicular cell proliferation, but significantly increases the spontaneous incidence of testicular TUNEL positive cells with increases in the Bax/Bcl2 expression ratio and apoptosis-inducing factor (AIF) expression. Diabetes induced significant increases in testicular TUNEL positive cells, Bax/Bcl2 expression ratio, AIF expression, CHOP and cleaved caspase-12 expression, and oxidative damage, but did not change the expression of cleaved caspase-3 and caspase-8. Deletion of Fgf21 gene also significantly enhances diabetes-induced TUNEL positive cells along with the increased expression of Bax/Bcl2 ratio, AIF, CHOP, cleaved caspase-12, and oxidative damage, which was significantly prevented by the supplementation of exogenous FGF21. These results suggest that Fgf21 gene may involve in maintaining normal spermatogenesis and also protect the germ cells from diabetes-induced apoptotic cell death probably via the prevention of diabetes-induced oxidative damage., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Fibroblast growth factor-21 (FGF21) is a potential metabolic regulator with multiple beneficial effects on metabolic diseases. FGF21 is mainly expressed in the liver, but is also found in other tissues including the intestine, which expresses β-klotho abundantly. The intestine is a unique organ that operates in a physiologically hypoxic environment, and is responsible for the fat absorption processes including triglyceride breakdown, re-synthesis and absorption into the portal circulation. In the present study, we investigated the effects of hypoxia and the chemical hypoxia inducer, cobalt chloride (CoCl(2)), on FGF21 expression in Caco-2 cells and the consequence of fat accumulation. Physical hypoxia (1% oxygen) and CoCl(2) treatment decreased both FGF21 mRNA and secreted protein levels. Gene silence and inhibition of hypoxia-inducible factor-α (HIFα) did not affect the reduction of FGF21 mRNA and protein levels by hypoxia. However, CoCl(2) administration caused a significant increase in oxidative stress. The addition of n-acetylcysteine (NAC) suppressed CoCl(2)-induced reactive oxygen species (ROS) formation and completely negated CoCl(2)-induced FGF21 loss. mRNA stability analysis demonstrated that the CoCl(2) administration caused a remarkable reduction in FGF21 mRNA stability. Furthermore, CoCl(2) increased intracellular triglyceride (TG) accumulation, along with a reduction in mRNA levels of lipid lipase, hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL), and an increase of sterol regulatory element-binding protein-1c (SREBP1c) and stearoyl-coenzyme A (SCD1). Addition of both NAC and recombinant FGF21 significantly attenuated the CoCl(2)-induced TG accumulation. In conclusion, the decrease of FGF21 in Caco-2 cells by chemical hypoxia is independent of HIFα, but dependent on an oxidative stress-mediated mechanism. The regulation of FGF21 by hypoxia may contribute to intestinal lipid metabolism and absorption., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Fibroblast growth factor 21 (FGF21) is a hepatic hormone involved in the regulation of lipid and carbohydrate metabolism. This study aims to test the hypothesis that elevated FGF21 concentrations are associated with the change of renal function and the presence of left ventricular hypertrophy (LVH) in the different stages of chronic kidney disease (CKD) progression., Methodology/principal Findings: 240 subjects including 200 CKD patients (146 outpatients and 54 long-term hemodialytic patients) and 40 healthy control subjects were recruited. All CKD subjects underwent echocardiograms to assess left ventricular mass index. Plasma FGF21 levels and other clinical and biochemical parameters in all subjects were obtained based on standard clinical examination methods. Plasma FGF21 levels were significantly increased with the development of CKD from early- and end-stage (P<0.001 for trend), and significantly higher in CKD subjects than those in healthy subjects (P<0.001). Plasma FGF21 levels in CKD patients with LVH were higher than those in patients without LVH (P = 0.001). Furthermore, plasma FGF21 level correlated positively with creatinine, blood urea nitrogen (BUN), β2 microglobulin, systolic pressure, adiponectin, phosphate, proteinuria, CRP and triglyceride, but negatively with creatinine clearance rate (CCR), estimated glomerular filtrate rate (eGFR), HDL-c, LDL-c, albumin and LVH after adjusting for BMI, gender, age and the presence of diabetes mellitus. Multiple stepwise regression analyses indicated that FGF21 was independently associated with BUN, Phosphate, LVMI and β2 microglobulin (all P<0.05)., Conclusion: Plasma FGF21 levels are significantly increased with the development of early- to end-stage CKD and are independently associated with renal function and adverse lipid profiles in Chinese population. Understanding whether increased FGF21 is associated with myocardial hypertrophy in CKD requires further study.

Background: Fibroblast growth factor 21 (FGF-21) is a metabolic regulator with multiple beneficial effects on glucose homeostasis and lipid metabolism in animal models. The relationship between plasma levels of FGF-21 and coronary heart disease (CHD) in unknown., Methodology/principal Findings: This study aimed to investigate the correlation of serum FGF-21 levels and lipid metabolism in the patients with coronary heart disease. We performed a logistic regression analysis of the relation between serum levels of FGF-21 and CHD patients with and without diabetes and hypertension. This study was conducted in the Departments of Endocrinology and Cardiovascular Diseases at two University Hospitals. Participants consisted of one hundred and thirty-five patients who have been diagnosed to have CHD and sixty-one control subjects. Serum FGF-21 level and levels of fasting blood glucose; triglyceride; apolipoprotein B100; HOMA-IR; insulin; total cholesterol; HDL-cholesterol; LDL-cholesterol; and C-reactive protein were measured. We found that median serum FGF-21 levels were significantly higher in CHD than that of control subjects (P<0.0001). Serum FGF-21 levels in CHD patients with diabetes, hypertension, or both were higher than that of patients without these comorbidities. Serum FGF-21 levels correlated positively with triglycerides, fasting blood glucose, apolipoprotein B100, insulin and HOMA-IR but negatively with HDL-C and apolipoprotein A1 after adjusting for BMI, diabetes and hypertension. Logistic regression analysis demonstrated that FGF-21 showed an independent association with triglyceride and apolipoprotein A1., Conclusions/significance: High levels of FGF-21 are associated with adverse lipid profiles in CHD patients. The paradoxical increase of serum FGF-21 in CHD patients may indicate a compensatory response or resistance to FGF-21.

Human acidic fibroblast growth factor (haFGF) stimulates repair and regeneration of central and peripheral nerves after various injuries. However, it is unable to cross the blood-brain barrier (BBB). To produce a therapeutic haFGF with cell-permeable activity, we fused the haFGF(19-154) gene with Tat-PTD. After its construction by a single-step insertion of a polymerase chain reaction (PCR)-amplified coding sequence, the vector pTat-haFGF(19-154)-His was expressed in Escherichia coli BL21 (DE3) cells. The optimal expression level of the soluble fusion protein was up to 36.7% of the total cellular protein. The recombinant Tat-haFGF(19-154)-His was purified by a combination of Ni-NTA affinity, Sephadex G-25, and heparin affinity chromatography to 95% as detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The final yield was 171 mg/l culture. Purified Tat-haFGF(19-154)-His had distinct mitogenic activity in Balb/c 3T3 cells, as measured by methylthiazoletetrazolium (MTT) assay and its ED(50) was 3.931 x 10(-4) micromol/l. Tat-haFGF(19-154)-His protein intravenously injected at the dose of 10 mg/kg could be detected in the pallium and hippocampi.

Molecular modification with polyethylene glycol (PEGylation) is an effective approach to improve protein biostability and decrease protein immunogenic activity. To create a PEGylated recombinant human acid fibroblast growth factor (rhaFGF) and improve its bio-stability, we have produced a rhaFGF mutant (rhaFGF(ser98,132)) by replacing the 98th and the 132nd cysteine residues with serine residues. The rhaFGF(ser98,132) that retains the bioactivity of rhaFGF was then site-specifically conjugated with PEG-maleimide at the 31st cysteine residue. PEGylated rhaFGF(ser98,132) has less effect than the native rhaFGF(ser98,132) on stimulating 3T3 cell proliferation in vitro; however, its biostability at a prolonged incubation under various temperatures and resistance to trypsinization were significantly enhanced, and half-life time in vivo was elongated while its immunogenicity was significantly decreased. The physiological function of PEGylated rhaFGF(ser98,132) was evaluated in a rat model of retinal ischemia/reperfusion injury, showing that in vivo supplementation of PEGylated rhaFGF(ser98,132) provided a significantly better protection than the native rhaFGF(ser98,132) against ischemia/reperfusion-induced retinal morphological changes and lipid peroxidation. The protection is probably mediated by antioxidant protective mechanisms.

Fibroblast growth factor 21 (FGF21) is a recently discovered hepatokine that regulates lipid and glucose metabolism and is upregulated in response to numerous physiological and pathological stimuli. Herein, we demonstrate that both physical and chemical hypoxia increase the systemic and hepatic expression of FGF21 in mice; by contrast, hypoxia induces a reduction of FGF21 expression in hepatocytes, indicating that hypoxia-induced FGF21 expression is differentially regulated in intact animals and in hepatocytes. Furthermore, we demonstrate that hypoxia treatment increases hormone-sensitive lipase-mediated adipose tissue lipolysis in mice, which is reduced in Fgf21 knockout mice, thereby implying that FGF21 plays a critical role in hypoxia-related adipose lipolysis. Adipose tissue lipolysis causes an increase in the amount of circulating free fatty acids, which leads to the activation of peroxisome proliferators-activated receptor alpha and an increased expression of FGF21 in hepatocytes. We further show that hypoxia-induced elevation of reactive oxygen species, but not the hypoxia-inducible factor, is responsible for the lipolysis and FGF21 expression. In conclusion, our data clearly demonstrate that FGF21 plays a critical role in hypoxia-induced adipose lipolysis, which induces hepatic expression of FGF21. Clarification of hypoxia-regulated FGF21 regulation will enhance our understanding of the pathophysiology of hypoxia-related diseases, such as sleep disorders and metabolic diseases. [ABSTRACT FROM AUTHOR]

Aims. Nutrient deficiencies are common in patients with inflammatory bowel disease (IBD). Adipose tissue plays a critical role in regulating energy balance. Fibroblast growth factor 21 (FGF21) is an important endocrine metabolic regulator with emerging beneficial roles in lipid homeostasis. We investigated the impact of FGF21 in experimental colitis-induced epididymal white adipose tissue (eWAT) lipolysis. Methods. Mice were given 2.5% dextran sulfate sodium (DSS) ad libitum for 7 days to induce colitis. The role of FGF21 was investigated using antibody neutralization or knockout (KO) mice. Lipolysis index and adipose lipolytic enzymes were determined. In addition, 3T3-L1 cells were pretreated with IL-6, followed by recombinant human FGF21 (rhFGF21) treatment; lipolysis was assessed. Results. DSS markedly decreased eWAT/body weight ratio and increased serum concentrations of free fatty acid (FFA) and glycerol, indicating increased adipose tissue lipolysis. eWAT intracellular lipolytic enzyme expression/activation was significantly increased. These alterations were significantly attenuated in FGF21 KO mice and by circulating FGF21 neutralization. Moreover, DSS treatment markedly increased serum IL-6 and FGF21 levels. IL-6 pretreatment was necessary for the stimulatory effect of FGF21 on adipose lipolysis in 3T3-L1 cells. Conclusions. Our results demonstrate that experimental colitis induces eWAT lipolysis via an IL-6/FGF21-mediated signaling pathway. [ABSTRACT FROM AUTHOR]

Abstract: Recombinant human keratinocyte growth factor 2 (rhKGF-2) is a member of fibroblast growth factor protein family currently being investigated for its promising significant effects in treating epithelial damage. Molecular modification with polyethylene glycol (PEGylation) is an effective approach to improve protein biostability and decrease protein immunogenic activity. In this study, we modified rhKGF-2 through PEGylation at N-terminal residue using 20kDa PEG-phenyl-isothiocyanate (PIT-PEG20K). PEGylated rhKGF-2 is then purified to near homogeneity by Sephadex G-25 gel filtration followed by a Heparin Sepharose TM CL-6B affinity chromatography. This PEGylated rhKGF-2 retained about 60% of mitogenic activity compared to the non-modified rhKGF-2. Its relative thermal stability at normal physiological temperature and structural stability were significantly enhanced. Moreover, the immunogenicity of PEGylated rhKGF-2 in mice is significant decreased compared to non-modified rhKGF-2. These results suggest that PEGylation of rhKGF-2 could be a more effective approach to the pharmacological and therapeutic application of rhKGF-2. [Copyright &y& Elsevier]