Regulative effects of the acupuncture on glucose and lipid metabolism disorder in the patients of metabolic syndrome

正Objective To observe the regulative effects of the acupuncture on glucose and lipid metabolism disorder in patients of metabolic syndrome.Methods Seventy-six patients of metabolic syndrome were randomized into an acupuncture plus western medicine group(37 cases)and a western medicine group(39 cases).In the western medicine group,the conventional western medication was     

Specific metabolic biomarkers as risk and prognostic factors in colorectal cancer

Advances in genomics,molecular pathology and metabolism have generated many candidate biomarkers of colorectal cancer with potential clinical value.Epidemiological and biological studies suggest a role for adiposity,dyslipidaemia,hyperinsulinemia,altered glucose homeostasis,and elevated expression of insulin-like growth factor(IGF)axis members in the risk and prognosis of cancer.This review discusses some recent past and current approaches being taken by researches in obesity and metabolic disorders.The authors describe three main systems as the most studied metabolic candidates of carcinogenesis:dyslipidemias,adipokines and insulin/IGF axis.However,each of these components is unsuccessful in defining the diseases risk and progression,while their co-occurrence increases cancer incidence and mortality in both men and women.     

Metabolic alterations and hepatitis C:From bench to bedside

In addition to causing cirrhosis and hepatocellular carcinoma, hepatitis C virus(HCV) is thought to cause hypolipidemia, hepatic steatosis, insulin resistance, metabolic syndrome, and diabetes. The viral life cycle of HCV depends on cholesterol metabolism in host cells. HCV core protein and nonstructural protein 5A perturb crucial lipid and glucose pathways, such as the sterol regulatory element-binding protein pathway and t he prot e in kinase B /mammal ian t arget of rapamycin/S6 kinase 1 pathway. Although several lines of transgenic mice expressing core or full HCV proteins exhibit hepatic steatosis and/or dyslipidemia, whether they completely reflect the metabolic alterations in humans with HCV infection remains unknown. Many cross-sectional studies have demonstrated increased prevalences of metabolic alterations and cardiovascular events in patients with chronic hepatitis C(CHC); however, conflicting results exist, primarily due to unavoidable individual variations. Utilizing anti-HCV therapy, most longitudinal cohort studies of CHC patients have demonstrated the favorable effects of viral clearance in attenuating metabolic alterations and cardiovascular risks. To determine the risks of HCV-associated metabolic alterations and associated complications in patients with CHC, it is necessary to adjust for crucial confounders, such as HCV genotype and host baseline glucose metabolism, for a long follow-up period after anti-HCV treatment. Adipose tissue is an important endocrine organ due to its release of adipocytokines, which regulate lipid and glucose metabolism. However, most data on HCV infection and adipocytokine alteration are inconclusive. A comprehensive overview of HCV-associated metabolic and adipocytokine alterations, from bench to bedside, is presented in this topic highlight.     

AMPK-associated signaling to bridge the gap between fuel metabolism and hepatocyte viability

The adenosine monophosphate-activated protein kinase (AMPK) and p70 ribosomal S6 kinase-1 pathway may serve as a key signaling flow that regulates energy metabolism; thus, this pathway becomes an attractive target for the treatment of liver diseases that result from metabolic derangements. In addition, AMPK emerges as a kinase that controls the redox-state and mitochondrial function, whose activity may be modulated by antioxidants. A close link exists between fuel metabolism and mitochondrial biogenesis. The relationship between fuel metabolism and cell survival strongly implies the existence of a shared signaling network, by which hepatocytes respond to challenges of external stimuli. The AMPK pathway may belong to this network. A series of drugs and therapeutic candidates enable hepatocytes to protect mitochondria from radical stress and increase cell viability, which may be associated with the activation of AMPK, liver kinase B1, and other molecules or components. Consequently, the components downstream of AMPK may contribute to stabilizing mitochondrial membrane potential for hepatocyte survival. In this review, we discuss the role of the AMPK pathway in hepatic energy metabolism and hepatocyte viability. This information may help identify ways to prevent and/or treat hepatic diseases caused by the metabolic syndrome. Moreover, clinical drugs and experimental therapeutic candidates that directly or indirectly modulate the AMPK pathway in distinct manners are discussed here with particular emphasis on their effects on fuel metabolism and mitochondrial function.     

Folic acid attenuates high-fat diet-induced steatohepatitis via deacetylase SIRT1-dependent restoration of PPARα

BACKGROUND Folic acid has been shown to improve non-alcoholic steatohepatitis(NASH), but its roles in hepatic lipid metabolism, hepatic one-carbon metabolism, and gut microbiota are still unknown.AIM To demonstrate the role of folic acid in lipid metabolism and gut microbiota in NASH.METHODS Twenty-four Sprague-Dawley rats were assigned into three groups: Chow diet,high-fat diet(HFD), and HFD with folic acid administration. At the end of 16 wk,the liver histology, the expression of hepatic genes related to lipid metabolism,one-carbon metabolism, and gut microbiota structure analysis of fecal samples based on 16 S r RNA sequencing were measured to evaluate the effect of folic acid.Palmitic acid-exposed Huh7 cell line was used to evaluate the role of folic acid in hepatic lipid metabolism.RESULTS Folic acid treatment attenuated steatosis, lobular inflammation, and hepatocellular ballooning in rats with HFD-induced steatohepatitis. Genes related to lipid de novo lipogenesis, β-oxidation, and lipid uptake were improvedin HFD-fed folic acid-treated rats. Furthermore, peroxisome proliferator-activated receptor alpha(PPARα) and silence information regulation factor 1(SIRT1) were restored by folic acid in HFD-fed rats and palmitic acid-exposed Huh7 cell line.The restoration of PPARα by folic acid was blocked after transfection with SIRT1 si RNA in the Huh7 cell line. Additionally, folic acid administration ameliorated depleted hepatic one-carbon metabolism and restored the diversity of the gut microbiota in rats with HFD-induced steatohepatitis.CONCLUSION Folic acid improves hepatic lipid metabolism by upregulating PPARα levels via a SIRT1-dependent mechanism and restores hepatic one-carbon metabolism and diversity of gut microbiota, thereby attenuating HFD-induced NASH in rats.     

Non-alcoholic fatty liver disease and psoriasis: So far,so near

Psoriasis is a chronic inflammatory immune-mediated skin diseases which is frequently associated to comorbidities. Non-alcoholic fatty liver disease(NAFLD) is defined as an excessive accumulation of triglycerides in hepatocytes and includes a wide spectrum of liver conditions ranging from relatively benign steatosis to non-alcoholic steatohepatitis with fatty infiltration and lobular inflammation and to cirrhosis and endstage liver disease. Actually, psoriasis is considered a systemic diseases associated to comorbidities, as metabolic syndrome and NAFLD is seen the hepatic manifestation of the metabolic syndrome. The possible link between psoriasis, obesity and metabolic syndrome, which are known risk factors for NAFLD has beenrecently documented focusing in the crucial role of the adipose tissue in the development of the inflammatory background sharing by the above entities. According to recent data, patients with psoriasis show a greater prevalence of NAFLD and metabolic syndrome than the general population. Moreover, patients with NAFLD and psoriasis are at higher risk of severe liver fibrosis than those with NAFLD and without psoriasis. The link between these pathological conditions appears to be a chronic low-grade inflammatory status. The aim of this review is to focus on the multiple aspects linking NAFLD and psoriasis, only apparently far diseases.     

Hepatitis C virus core protein modulates several signaling pathways involved in hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is the fifth most common cancer, and hepatitis C virus(HCV) infection plays a major role in HCC development. The molecular mechanisms by which HCV infection leads to HCC are varied. HCV core protein is an important risk factor in HCV-associated liver pathogenesis and can modulate several signaling pathways involved in cell cycle regulation, cell growth promotion, cell proliferation, apoptosis, oxidative stress and lipid metabolism. The dysregulation of signaling pathways such as transforming growth factor β(TGF-β), vascular endothelial growth factor(VEGF), Wnt/β-catenin(WNT), cyclooxygenase-2(COX-2) and peroxisome proliferator-activated receptor α(PPARα) by HCV core protein is implicated in the development of HCC. Therefore, it has been suggested that this protein be considered a favorable target for further studies in the development of HCC. In addition, considering the axial role of these signaling pathways in HCC, they are considered druggable targets for cancer therapy. Therefore, using strategies to limit the dysregulation effects of core protein on these signaling pathways seems necessary to prevent HCV-related HCC.     

Normal glucose uptake in the brain and heart requires an endothelial cell-specific HIF-1α–dependent function

Although intimately positioned between metabolic substrates in the bloodstream and the tissue parenchymal cells that require these substrates, a major role of the vascular endothelium in the regulation of tissue metabolism has not been widely appreciated. We hypothesized that via control of transendothelial glucose transport and contributing paracrine mechanisms the endothelium plays a major role in regulating organ and tissue glucose metabolism. We further hypothesized that the hypoxia-inducible factor -1α (HIF-1α) plays an important role in coordinating these endothelial functions. To test these hypotheses, we generated mice with endothelial cell-specific deletion of HIF-1α. Loss of HIF in the endothelium resulted in significantly increased fasting blood glucose levels, a blunted insulin response with delayed glucose clearance from the blood after i.v. loading, and significantly decreased glucose uptake into the brain and heart. Endothelial HIF-1α knockout mice also exhibited a reduced cerebrospinal fluid/blood glucose ratio, a finding consistent with reduced transendothelial glucose transport and a diagnostic criterion for the Glut1 deficiency genetic syndrome. Endothelial cells from these mice demonstrated decreased Glut1 levels and reduced glucose uptake that was reversed by forced expression of Glut1. These data strongly support an important role of the vascular endothelium in determining whole-organ glucose metabolism and indicate that HIF-1α is a critical mediator of this function.     

内脂素与代谢综合征关系的研究进展

内脂素是新近发现的由内脏脂肪细胞分泌的一种脂肪因子,与前B细胞克隆增强因子结构相同,具有胰岛素样作用、能促进脂肪的积聚和合成、参与动脉粥样硬化的形成、调节血管平滑肌的成熟,因此内脂素可能是联系糖脂代谢紊乱以及心血管疾病的新纽带,这为代谢综合征的防治提供了新的方向。但目前的研究方法尚不完善,研究结论不统一,尚有大量工作需要去做。     

Enhanced caveolin-1 expression in smooth muscle cells: Possible prelude to neointima formation

AIM: To study the genesis of neointima formation in pulmonary hypertension (PH), we investigated the role of caveolin-1 and related proteins.METHODS: Male Sprague Dawley rats were given monocrotaline (M, 40 mg/kg) or subjected to hypobaric hypoxia (H) to induce PH. Another group was given M and subjected to H to accelerate the disease process (M + H). Right ventricular systolic pressure, right ventricular hypertrophy, lung histology for medial hypertrophy and the presence of neointimal lesions were examined at 2 and 4 wk. The expression of caveolin-1 and its regulatory protein peroxisome proliferator-activated receptor (PPAR) γ, caveolin-2, proliferative and anti-apoptotic factors (PY-STAT3, p-Erk, Bcl-xL), endothelial nitric oxide synthase (eNOS) and heat shock protein (HSP) 90 in the lungs were analyzed, and the results from M + H group were compared with the controls, M and H groups. Double immunofluorescence technique was used to identify the localization of caveolin-1 in pulmonary arteries in rat lungs and in human PH lung tissue.RESULTS: In the M + H group, PH was more severe compared with M or H group. In the 4 wk M+H group, several arteries with reduced caveolin-1 expression in endothelial layer coupled with an increased expression in smooth muscle cells (SMC), exhibited neointimal lesions. Neointima was present only in the arteries exhibiting enhanced caveolin-1 expression in SMC. Lung tissue obtained from patients with PH also revealed neointimal lesions only in the arteries exhibiting endothelial caveolin-1 loss accompanied by an increased caveolin-1 expression in SMC. Reduction in eNOS and HSP90 expression was present in the M groups (2 and 4 wk), but not in the M + H groups. In both M groups and in the M + H group at 2 wk, endothelial caveolin-1 loss was accompanied by an increase in PPARγ expression. In the M + H group at 4 wk, increase in caveolin-1 expression was accompanied by a reduction in the PPARγ expression. In the H group, there was neither a loss of endothelial caveolin-1, eNOS or HSP90, nor an increase in SMC caveolin-1 expression; or any alteration in PPARγ expression. Proliferative pathways were activated in all experimental groups.CONCLUSION: Enhanced caveolin-1 expression in SMC follows extensive endothelial caveolin-1 loss with subsequent neointima formation. Increased caveolin-1 expression in SMC, thus, may be a prelude to neointima formation.     

Getting ‘Smad' about obesity and diabetes

Recent findings on the role of transforming growth factor (TGF)-β/Smad3 signaling in the pathogenesis of obesity and type 2 diabetes have underscored its importance in metabolism and adiposity. Indeed, elevated TGF-β has been previously reported in human adipose tissue during morbid obesity and diabetic neuropathy. In this review, we discuss the pleiotropic effects of TGF-β/Smad3 signaling on metabolism and energy homeostasis, all of which has an important part in the etiology and progression of obesity-linked diabetes; these include adipocyte differentiation, white to brown fat phenotypic transition, glucose and lipid metabolism, pancreatic function, insulin signaling, adipocytokine secretion, inflammation and reactive oxygen species production. We summarize the recent in vivo findings on the role of TGF-β/Smad3 signaling in metabolism based on the studies using Smad3^−/− mice. Based on the presence of a dual regulatory effect of Smad3 on peroxisome proliferator-activated receptor (PPAR)β/δ and PPARγ2 promoters, we propose a unifying mechanism by which this signaling pathway contributes to obesity and its associated diabetes. We also discuss how the inhibition of this signaling pathway has been implicated in the amelioration of many facets of metabolic syndromes, thereby offering novel therapeutic avenues for these metabolic conditions.     

Increased lipolysis and altered lipid homeostasis protect γ-synuclein–null mutant mice from diet-induced obesity

Synucleins are a family of homologous proteins principally known for their involvement in neurodegeneration. γ-Synuclein is highly expressed in human white adipose tissue and increased in obesity. Here we show that γ-synuclein is nutritionally regulated in white adipose tissue whereas its loss partially protects mice from high-fat diet (HFD)–induced obesity and ameliorates some of the associated metabolic complications. Compared with HFD-fed WT mice, HFD-fed γ-synuclein–null mutant mice display increased lipolysis, lipid oxidation, and energy expenditure, and reduced adipocyte hypertrophy. Knockdown of γ-synuclein in adipocytes causes redistribution of the key lipolytic enzyme ATGL to lipid droplets and increases lipolysis. γ-Synuclein–deficient adipocytes also contain fewer SNARE complexes of a type involved in lipid droplet fusion. We hypothesize that γ-synuclein may deliver SNAP-23 to the SNARE complexes under lipogenic conditions. Via these independent but complementary roles, γ-synuclein may coordinately modulate lipid storage by influencing lipolysis and lipid droplet formation. Our data reveal γ-synuclein as a regulator of lipid handling in adipocytes, the function of which is particularly important in conditions of nutrient excess.Understanding the link between increased adiposity and the development of metabolic disease may reveal novel therapeutic targets to counter the rising pandemic of obesity. Inhibiting adipose tissue expansion alone is likely to worsen metabolic outcome, as evidenced by human syndromes of lipodystrophy, whereby inappropriately decreased adipose mass causes severe metabolic disorders (1). Indeed, adipose tissue dysfunction and/or exceeded adipose storage capacity may underlie ectopic lipid accumulation and lipotoxicity in obesity (2). Therefore, a major challenge is to identify pathways via which adiposity can be reduced without concomitant increases in circulating lipids and attendant metabolic disease. Achieving this goal requires a better understanding of the molecular mechanisms that regulate lipid metabolism and storage in adipocytes, particularly in times of energy surplus.γ-Synuclein belongs to the synuclein family of proteins, whose founder member α-synuclein is best known for its links with neurodegenerative diseases, most notably Parkinson disease (3). To date, no clear cellular role is attributed to γ-synuclein, and ablation of γ-synuclein causes only minor changes in the nervous system (4–7). Recently, we and others have reported high levels of γ-synuclein expression in adipose tissue of humans and other mammals (8, 9). Moreover, expression of γ-synuclein is increased in the adipose tissue of obese humans and decreased during caloric restriction (8).Here we demonstrate that γ-synuclein–null mice display significantly reduced adiposity and fewer metabolic derangements compared with WT mice following high-fat feeding. This appears to result from increased adipocyte lipolysis coupled to enhanced whole-body lipid oxidation and energy expenditure. At a molecular level, we identify dual roles for γ-synuclein independently regulating lipid droplet fusion and adipocyte lipolysis to coordinately regulate triglyceride (TG) storage in adipocytes. Together, our observations reveal that γ-synuclein is a regulator of lipid metabolism and, hence, a potential therapeutic target for treatment of obesity and associated metabolic diseases.