201
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García-Cañaveras JC, Peris-Díaz MD, Alcoriza-Balaguer MI, Cerdán-Calero M, Donato MT, Lahoz A. A lipidomic cell-based assay for studying drug-induced phospholipidosis and steatosis. Electrophoresis 2017; 38:2331-2340. [PMID: 28512733 DOI: 10.1002/elps.201700079] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 04/28/2017] [Accepted: 05/10/2017] [Indexed: 12/19/2022]
Abstract
Phospholipidosis and steatosis are two toxic effects, which course with overaccumulation of different classes of lipids in the liver. MS-based lipidomics has become a powerful tool for the comprehensive determination of lipids. LC-MS lipid profiling of HepG2 cells is proposed as an in vitro assay to study and anticipate phospholipidosis and steatosis. Cells with and without preincubation with a mixture of free fatty acids (FFA; i.e. oleic and palmitic) were exposed to a set of well-known steatogenic and phospholipidogenic compounds. The use of FFA preloading accelerated the accumulation of phospholipids, thus leading to a better discrimination of phospholipidosis, and magnified the lipidomic alterations induced by steatogenic drugs. Phospholipidosis was characterized by increased levels of phosphatidylcholines, phosphatidylethanolamines, phosphatidylserines, and phosphatidylinositols, while steatosis induced alterations in FA oxidation and triacylglyceride (TG) synthesis pathways (with changes in the levels of FFA, acylcarnitines, monoacylglycerides, diacylglycerides, and TG). Interestingly, palmitic and oleic acids incorporation into lipids differed. A characteristic pattern was observed in the fold of change of particular TG species in the case of steatosis (TG(54:3) > TG(52:2) > TG(50:1) > TG(48:0)). Based on the levels of those lipids containing only palmitic and/or oleic acid moieties a partial least squares-discriminant analysis model was built, which showed good discrimination among nontoxic, phospholipidogenic and steatogenic compounds. In conclusion, it has been shown that the use of FFA preincubation together with intracellular LC-MS based lipid profiling could be a useful approach to identify the potential of drug candidates to induce phospholipidosis and/or steatosis.
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Affiliation(s)
- Juan Carlos García-Cañaveras
- Unidad de Biomarcadores y Medicina de Precisión, Unidad Analítica, Instituto de Investigación Sanitaria, Fundación Hospital La Fe, Spain
| | - Manuel David Peris-Díaz
- Unidad de Biomarcadores y Medicina de Precisión, Unidad Analítica, Instituto de Investigación Sanitaria, Fundación Hospital La Fe, Spain
| | - M Isabel Alcoriza-Balaguer
- Unidad de Biomarcadores y Medicina de Precisión, Unidad Analítica, Instituto de Investigación Sanitaria, Fundación Hospital La Fe, Spain
| | - Manuela Cerdán-Calero
- Unidad de Biomarcadores y Medicina de Precisión, Unidad Analítica, Instituto de Investigación Sanitaria, Fundación Hospital La Fe, Spain
| | - M Teresa Donato
- Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria, Fundación Hospital La Fe, Spain.,Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Valencia, Spain
| | - Agustín Lahoz
- Unidad de Biomarcadores y Medicina de Precisión, Unidad Analítica, Instituto de Investigación Sanitaria, Fundación Hospital La Fe, Spain
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202
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Ginsenoside Rb2 Alleviates Hepatic Lipid Accumulation by Restoring Autophagy via Induction of Sirt1 and Activation of AMPK. Int J Mol Sci 2017; 18:ijms18051063. [PMID: 28534819 PMCID: PMC5454975 DOI: 10.3390/ijms18051063] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/26/2017] [Accepted: 05/09/2017] [Indexed: 12/16/2022] Open
Abstract
Although Panax ginseng is a famous traditional Chinese medicine and has been widely used to treat a variety of metabolic diseases including hyperglycemia, hyperlipidemia, and hepatosteatosis, the effective mediators and molecular mechanisms remain largely unknown. In this study we found that ginsenoside Rb2, one of the major ginsenosides in Panax ginseng, was able to prevent hepatic lipid accumulation through autophagy induction both in vivo and in vitro. Treatment of male db/db mice with Rb2 significantly improved glucose tolerance, decreased hepatic lipid accumulation, and restored hepatic autophagy. In vitro, Rb2 (50 µmol/L) obviously increased autophagic flux in HepG2 cells and primary mouse hepatocytes, and consequently reduced the lipid accumulation induced by oleic acid in combination with high glucose. Western blotting analysis showed that Rb2 partly reversed the high fatty acid in combination with high glucose (OA)-induced repression of autophagic pathways including AMP-activated protein kinase (AMPK) and silent information regulator 1 (sirt1). Furthermore, pharmacological inhibition of the sirt1 or AMPK pathways attenuated these beneficial effects of Rb2 on hepatic autophagy and lipid accumulation. Taken together, these results suggested that Rb2 alleviated hepatic lipid accumulation by restoring autophagy via the induction of sirt1 and activation of AMPK, and resulted in improved nonalcoholic fatty liver disease (NAFLD) and glucose tolerance.
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203
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AISF position paper on nonalcoholic fatty liver disease (NAFLD): Updates and future directions. Dig Liver Dis 2017; 49:471-483. [PMID: 28215516 DOI: 10.1016/j.dld.2017.01.147] [Citation(s) in RCA: 225] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 01/08/2017] [Accepted: 01/10/2017] [Indexed: 02/07/2023]
Abstract
This review summarizes our current understanding of nonalcoholic fatty liver disease (NAFLD), a multi-factorial systemic disease resulting from a complex interaction between a specific genetic background and multiple environmental/metabolic "hits". The role of gut microbiota, lipotoxicity, inflammation and their molecular pathways is reviewed in-depth. We also discuss the epidemiology and natural history of NAFLD by pinpointing the remarkably high prevalence of NAFLD worldwide and its inherent systemic complications: hepatic (steatohepatitis, advanced fibrosis and cirrhosis), cardio-metabolic (cardiovascular disease, cardiomyopathy, arrhythmias and type 2 diabetes) and neoplastic (primary liver cancers and extra-hepatic cancers). Moreover, we critically report on the diagnostic role of non-invasive biomarkers, imaging techniques and liver biopsy, which remains the reference standard for diagnosing the disease, but cannot be proposed to all patients with suspected NAFLD. Finally, the management of NAFLD is also reviewed, by highlighting the lifestyle changes and the pharmacological options, with a focus on the innovative drugs. We conclude that the results of ongoing studies are eagerly expected to lead to introduce into the clinical arena new diagnostic and prognostic biomarkers, prevention and surveillance strategies as well as to new drugs for a tailored approach to the management of NAFLD in the individual patient.
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204
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Cheng F, Ma C, Wang X, Zhai C, Wang G, Xu X, Mu J, Li C, Wang Z, Zhang X, Yue W, Du X, Lian Y, Zhu W, Yin X, Wei Z, Song W, Wang Q. Effect of traditional Chinese medicine formula Sinisan on chronic restraint stress-induced nonalcoholic fatty liver disease: a rat study. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 17:203. [PMID: 28388904 PMCID: PMC5383977 DOI: 10.1186/s12906-017-1707-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/24/2017] [Indexed: 02/08/2023]
Abstract
Background Nonalcoholic fatty liver disease (NAFLD) represents one of the most common forms of liver disease worldwide, and it is always regarded as a consequence of a sedentary, food-abundant lifestyle, sitting for an extended time, and a low physical activity level, which often coincide with chronic and long-lasting psychological stress. A Chinese medicine Sinisan (SNS) may be a potential formula for treating this kind of disease. Methods In this study, a long-term chronic restraint stress protocol was used to investigate the mechanism underlying stress-induced NALFD. To investigate the effect of SNS treatment on stress-induced NAFLD, we measured the liver and serum values of total cholesterol (TC), triglyceride (TG), liver free fatty acids (FFA), low-density lipoprotein, superoxide dismutase, tumor necrosis factor-α, malondialdehyde, interleukin (IL)-6, and serum values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase. Results are shown as a mean ± standard deviation. Significant differences between the groups were evaluated using the Student t-test. For multiple comparisons, one-way analysis of variance (ANOVA) was used. If the results of ANOVA indicated significant differences, post hoc analysis was performed with the Tukey test or Dunnett test, and p < 0.05 was considered statistically significant. Results Long-term chronic stress led to steatosis and non-alcoholic steatohepatitis. Additionally, SNS treatment significantly increased body weight gain (p < 0.01) and sucrose preference (p < 0.001), and it reduced the liver values of TC, TG, and FFA (p < 0.05). SNS also reduced the serum values of AST and ALT (p < 0.001), and the liver value of IL-6 (p < 0.01). Conclusions This study’s results demonstrate that psychological stress may be a significant risk factor of NAFLD. Furthermore, the traditional Chinese medicine formula SNS may have some beneficial effect in antagonizing psychological stress and stress-related NAFLD.
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205
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Hirata Y, Takahashi M, Kudoh Y, Kano K, Kawana H, Makide K, Shinoda Y, Yabuki Y, Fukunaga K, Aoki J, Noguchi T, Matsuzawa A. trans-Fatty acids promote proinflammatory signaling and cell death by stimulating the apoptosis signal-regulating kinase 1 (ASK1)-p38 pathway. J Biol Chem 2017; 292:8174-8185. [PMID: 28360100 DOI: 10.1074/jbc.m116.771519] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 03/29/2017] [Indexed: 12/14/2022] Open
Abstract
Food-borne trans-fatty acids (TFAs) are mainly produced as byproducts during food manufacture. Recent epidemiological studies have revealed that TFA consumption is a major risk factor for various disorders, including atherosclerosis. However, the underlying mechanisms in this disease etiology are largely unknown. Here we have shown that TFAs potentiate activation of apoptosis signal-regulating kinase 1 (ASK1) induced by extracellular ATP, a damage-associated molecular pattern leaked from injured cells. Major food-associated TFAs such as elaidic acid (EA), linoelaidic acid, and trans-vaccenic acid, but not their corresponding cis isomers, dramatically enhanced extracellular ATP-induced apoptosis, accompanied by elevated activation of the ASK1-p38 pathway in a macrophage-like cell line, RAW264.7. Moreover, knocking out the ASK1-encoding gene abolished EA-mediated enhancement of apoptosis. We have reported previously that extracellular ATP induces apoptosis through the ASK1-p38 pathway activated by reactive oxygen species generated downstream of the P2X purinoceptor 7 (P2X7). However, here we show that EA did not increase ATP-induced reactive oxygen species generation but, rather, augmented the effects of calcium/calmodulin-dependent kinase II-dependent ASK1 activation. These results demonstrate that TFAs promote extracellular ATP-induced apoptosis by targeting ASK1 and indicate novel TFA-associated pathways leading to inflammatory signal transduction and cell death that underlie the pathogenesis and progression of TFA-induced atherosclerosis. Our study thus provides insight into the pathogenic mechanisms of and proposes potential therapeutic targets for these TFA-related disorders.
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Affiliation(s)
| | | | | | - Kuniyuki Kano
- Laboratory of Molecular and Cellular Biochemistry; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, 100-0004 Tokyo, Japan
| | | | | | - Yasuharu Shinoda
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba-ku, 980-8578 Sendai, Japan
| | - Yasushi Yabuki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba-ku, 980-8578 Sendai, Japan
| | - Kohji Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba-ku, 980-8578 Sendai, Japan
| | - Junken Aoki
- Laboratory of Molecular and Cellular Biochemistry; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, 100-0004 Tokyo, Japan
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206
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Jorgačević B, Vučević D, Đuričić I, Šobajić S, Mladenović D, Vesković M, Vukićević RJ, Radosavljević T. The effect of cannabinoid receptor 1 blockade on hepatic free fatty acid profile in mice with nonalcoholic fatty liver disease. Chem Phys Lipids 2017; 204:85-93. [PMID: 28363784 DOI: 10.1016/j.chemphyslip.2017.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 03/06/2017] [Accepted: 03/14/2017] [Indexed: 02/05/2023]
Abstract
We used rimonabant to investigate the role of CB1 receptor on hepatic FFAs profile during NAFLD. Male mice C57BL/6 were divided into: control group fed with control diet 20 weeks (C; n=6); group fed with HFD 20 weeks (HF; n=6); group fed with control diet and treated with rimonabant after 18 weeks (R; n=9); group fed with HFD and treated with rimonabant after 18 weeks (HFR; n=10). Rimonabant (10mg/kg) was administered daily to HFR and R group by oral gavage. Rimonabant decreased liver palmitic acid proportion in HFR group compared to HF group (p<0.05). Liver stearic and oleic acid proportions were decreased in R group compared to control (p<0.01 respectively). Rimonabant increased liver linoleic and arachidonic acid proportions in HFR group compared to HF group (p<0.01 respectively). CB1 blockade may be useful in the treatment of HFD-induced NAFLD due to modulation of plasma lipid and hepatic FFA profile.
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Affiliation(s)
- Bojan Jorgačević
- Institute of Pathophysiology "Ljubodrag Buba Mihailović", Faculty of Medicine, University of Belgrade, Serbia
| | - Danijela Vučević
- Institute of Pathophysiology "Ljubodrag Buba Mihailović", Faculty of Medicine, University of Belgrade, Serbia
| | - Ivana Đuričić
- Department for Bromatology, Faculty of Farmacy, University of Belgrade, Serbia
| | - Slađana Šobajić
- Department for Bromatology, Faculty of Farmacy, University of Belgrade, Serbia
| | - Dušan Mladenović
- Institute of Pathophysiology "Ljubodrag Buba Mihailović", Faculty of Medicine, University of Belgrade, Serbia
| | - Milena Vesković
- Institute of Pathophysiology "Ljubodrag Buba Mihailović", Faculty of Medicine, University of Belgrade, Serbia
| | | | - Tatjana Radosavljević
- Institute of Pathophysiology "Ljubodrag Buba Mihailović", Faculty of Medicine, University of Belgrade, Serbia.
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207
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Gelen V, Şengül E, Gedikli S, Gür C, Özkanlar S. Therapeutic effect of quercetin on renal function and tissue damage in the obesity induced rats. Biomed Pharmacother 2017; 89:524-528. [PMID: 28254664 DOI: 10.1016/j.biopha.2017.02.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 02/16/2017] [Accepted: 02/16/2017] [Indexed: 02/05/2023] Open
Affiliation(s)
- Volkan Gelen
- Department of Physiology, Veterinary Faculty, Kafkas University, Kars, Turkey.
| | - Emin Şengül
- Department of Physiology, Veterinary Faculty, Atatürk University, Erzurum, Turkey
| | - Semin Gedikli
- Department of Histology-Embryology, Veterinary Faculty, Atatürk University, Erzurum, Turkey
| | - Cihan Gür
- Department of Biochemistry, Veterinary Faculty, Atatürk University, Erzurum, Turkey
| | - Seçkin Özkanlar
- Department of Biochemistry, Veterinary Faculty, Atatürk University, Erzurum, Turkey
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208
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Love S, Mudasir MA, Bhardwaj SC, Singh G, Tasduq SA. Long-term administration of tacrolimus and everolimus prevents high cholesterol-high fructose-induced steatosis in C57BL/6J mice by inhibiting de-novo lipogenesis. Oncotarget 2017; 8:113403-113417. [PMID: 29371918 PMCID: PMC5768335 DOI: 10.18632/oncotarget.15194] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 11/02/2016] [Indexed: 12/15/2022] Open
Abstract
Aim To investigate the effects of tacrolimus (TC) and everolimus (EV) on non-alcoholic steatohepatitis (NASH) induced by high fat, high cholesterol and fructose (fast food) diet in C57BL/6J mice. Materials and Methods C57BL/6J mice were divided into four groups (n=8). 1) Standard Chow (SC); 2) Fast food (FF) diet; 3) FF + Tacrolimus (TC, 1mg/kg) and; 4) FF + Everolimus (EV, 1mg/kg) and treated for 16 weeks. Serum and tissue samples were analyzed for evidence of inflammation, fibrosis, lipogenesis, and apoptosis. Results TC and EV treatments significantly reduced the hepatic lipid accumulation, improved liver-body weight ratio, blood biochemistry, and insulin resistance in mice fed with FF diet. However, inflammation, enlarged portal tracts, and fibrosis were pronounced in EV treated group. The lipogenic parameters, Peroxisome proliferator-activated receptor gamma (PPAR-γ), Sterol regulatory element-binding protein 1(SREBP-1), mammalian target of rapamycin (m-TOR), Stearoyl-CoA desaturase-1 (SCD-1) and fatty acid translocase (CD36) were significantly down-regulated in livers of TC and EV treated groups as compared to FF group. TC improved Bcl2/Bax ratio, decreased apoptosis, CYP2E1 protein expression and liver fibrosis levels, however, EV offered no such protection. Further, in an In-vitro model of lipotoxicity using the mouse hepatocyte (AML-12) cell line, treatment with TC and EV significantly reduced lipid accumulation and lipogenic and apoptotic markers induced with palmitic acid. Conclusion In FF diet induced model of NASH, both TC and EV inhibited hepatic lipid accumulation and improved metabolic parameters such as insulin resistance and dyslipidemia. However, mice administered with EV exhibited inflammatory and fibrotic responses despite reduced hepatic steatosis.
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Affiliation(s)
- Sharma Love
- PK-PD and Toxicology Division, CSIR-Indian Institute of Integrative Medicine, Jammu Tawi, Jammu and Kashmir, India.,Academy of Scientific and Innovative Research (AcSIR), Chennai, India
| | - Malik A Mudasir
- PK-PD and Toxicology Division, CSIR-Indian Institute of Integrative Medicine, Jammu Tawi, Jammu and Kashmir, India
| | - Subhash C Bhardwaj
- Department of Pathology, Government Medical College, Jammu, Jammu and Kashmir, India
| | - Gurdarshan Singh
- PK-PD and Toxicology Division, CSIR-Indian Institute of Integrative Medicine, Jammu Tawi, Jammu and Kashmir, India.,Academy of Scientific and Innovative Research (AcSIR), Chennai, India
| | - Sheikh A Tasduq
- PK-PD and Toxicology Division, CSIR-Indian Institute of Integrative Medicine, Jammu Tawi, Jammu and Kashmir, India.,Academy of Scientific and Innovative Research (AcSIR), Chennai, India
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209
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Mika A, Sledzinski T. Alterations of specific lipid groups in serum of obese humans: a review. Obes Rev 2017; 18:247-272. [PMID: 27899022 DOI: 10.1111/obr.12475] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/16/2016] [Accepted: 09/05/2016] [Indexed: 12/15/2022]
Abstract
Obesity is a major contributor to the dysfunction of liver, cardiac, pulmonary, endocrine and reproductive system, as well as a component of metabolic syndrome. Although development of obesity-related disorders is associated with lipid abnormalities, most previous studies dealing with the problem in question were limited to routinely determined parameters, such as serum concentrations of triacylglycerols, total cholesterol, low-density and high-density lipoprotein cholesterol. Many authors postulated to extend the scope of analysed lipid compounds and to study obesity-related alterations in other, previously non-examined groups of lipids. Comprehensive quantitative, structural and functional analysis of specific lipid groups may result in identification of new obesity-related alterations. The review summarizes available evidence of obesity-related alterations in various groups of lipids and their impact on health status of obese subjects. Further, the role of diet and endogenous lipid synthesis in the development of serum lipid alterations is discussed, along with potential application of various lipid compounds as risk markers for obesity-related comorbidities.
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Affiliation(s)
- A Mika
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
| | - T Sledzinski
- Department of Pharmaceutical Biochemistry, Medical University of Gdansk, Gdansk, Poland
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210
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Sinha RA, Singh BK, Yen PM. Reciprocal Crosstalk Between Autophagic and Endocrine Signaling in Metabolic Homeostasis. Endocr Rev 2017; 38:69-102. [PMID: 27901588 DOI: 10.1210/er.2016-1103] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/28/2016] [Indexed: 12/19/2022]
Abstract
Autophagy is a cellular quality control and energy-providing process that is under strict control by intra- and extracellular stimuli. Recently, there has been an exponential increase in autophagy research and its implications for mammalian physiology. Autophagy deregulation is now being implicated in many human diseases, and its modulation has shown promising results in several preclinical studies. However, despite the initial discovery of autophagy as a hormone-regulated process by De Duve in the early 1960s, endocrine regulation of autophagy still remains poorly understood. In this review, we provide a critical summary of our present understanding of the basic mechanism of autophagy, its regulation by endocrine hormones, and its contribution to endocrine and metabolic homeostasis under physiological and pathological settings. Understanding the cross-regulation of hormones and autophagy on endocrine cell signaling and function will provide new insight into mammalian physiology as well as promote the development of new therapeutic strategies involving modulation of autophagy in endocrine and metabolic disorders.
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Affiliation(s)
- Rohit A Sinha
- Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School Singapore, Singapore 169016
| | - Brijesh K Singh
- Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School Singapore, Singapore 169016
| | - Paul M Yen
- Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Medical School Singapore, Singapore 169016
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211
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Croce AC, Bottiroli G. Autofluorescence Spectroscopy for Monitoring Metabolism in Animal Cells and Tissues. Methods Mol Biol 2017; 1560:15-43. [PMID: 28155143 DOI: 10.1007/978-1-4939-6788-9_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Excitation of biological substrates with light at a suitable wavelength can give rise to a light emission in the ultraviolet (UV)-visible, near-infrared (IR) spectral range, called autofluorescence (AF). This is a widespread phenomenon, ascribable to the general presence of biomolecules acting as endogenous fluorophores (EFs) in the organisms of the whole life kingdom. In cytochemistry and histochemistry, AF is often an unwanted signal enhancing the background and affecting in particular the detection of low signals or rare positive labeling spots of exogenous markers. Conversely, AF is increasingly considered as a powerful diagnostic tool because of its role as an intrinsic biomarker directly dependent on the nature, amount, and microenvironment of the EFs, in a strict relationship with metabolic processes and structural organization of cells and tissues. As a consequence, AF carries multiple information that can be decrypted by a proper analysis of the overall emission signal, allowing the characterization and monitoring of cell metabolism in situ, in real time and in the absence of perturbation from exogenous markers. In the animal kingdom, AF studies at the cellular level take advantage of the essential presence of NAD(P)H and flavins, primarily acting as coenzymes at multiple steps of common metabolic pathways for energy production, reductive biosynthesis and antioxidant defense. Additional EFs such as vitamin A, porphyrins, lipofuscins, proteins, and neuromediators can be detected in different kinds of cells and bulk tissues, and can be exploited as photophysical biomarkers of specific normal or altered morphofunctional properties, from the retinoid storage in the liver to aging processes, metabolic disorders or cell transformation processes. The AF phenomenon involves all living system, and literature reports numerous investigations and diagnostic applications of AF, taking advantage of continuously developing self-assembled or commercial instrumentation and measuring procedures, making almost impossible to provide their comprehensive description. Therefore a brief summary of the history of AF observations and of the development of measuring systems is provided, along with a description of the most common EFs and their metabolic significance. From our direct experience, examples of AF imaging and microspectrofluorometric procedures performed under a single excitation in the near-UV range for cell and tissue metabolism studies are then reported.
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Affiliation(s)
- Anna C Croce
- Institute of Molecular Genetics (IGM) - CNR, via Abbiategrasso, 207, 27100, Pavia, Italy.
| | - Giovanni Bottiroli
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy
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212
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Dong Y, Fernandes C, Liu Y, Wu Y, Wu H, Brophy ML, Deng L, Song K, Wen A, Wong S, Yan D, Towner R, Chen H. Role of endoplasmic reticulum stress signalling in diabetic endothelial dysfunction and atherosclerosis. Diab Vasc Dis Res 2017; 14:14-23. [PMID: 27941052 PMCID: PMC5161113 DOI: 10.1177/1479164116666762] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
It is well established that diabetes mellitus accelerates atherosclerotic vascular disease. Endothelial injury has been proposed to be the initial event in the pathogenesis of atherosclerosis. Endothelium not only acts as a semi-selective barrier but also serves physiological and metabolic functions. Diabetes or high glucose in circulation triggers a series of intracellular responses and organ damage such as endothelial dysfunction and apoptosis. One such response is high glucose-induced chronic endoplasmic reticulum stress in the endothelium. The unfolded protein response is an acute reaction that enables cells to overcome endoplasmic reticulum stress. However, when chronically persistent, endoplasmic reticulum stress response could ultimately lead to endothelial dysfunction and atherosclerosis. Herein, we discuss the scientific advances in understanding endoplasmic reticulum stress-induced endothelial dysfunction, the pathogenesis of diabetes-accelerated atherosclerosis and endoplasmic reticulum stress as a potential target in therapies for diabetic atherosclerosis.
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Affiliation(s)
- Yunzhou Dong
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Yanjun Liu
- Department of Internal Medicine, Charles R. Drew University of Medicine and Science, University of California-Los Angeles School of Medicine, Los Angeles, CA, USA
| | - Yong Wu
- Department of Internal Medicine, Charles R. Drew University of Medicine and Science, University of California-Los Angeles School of Medicine, Los Angeles, CA, USA
| | - Hao Wu
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Megan L Brophy
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lin Deng
- Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Kai Song
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Aiyun Wen
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Scott Wong
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Daoguang Yan
- Department of Biology, Jinan University, Guangzhou, China
| | - Rheal Towner
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma, OK, USA
| | - Hong Chen
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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213
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Veum VL, Laupsa-Borge J, Eng Ø, Rostrup E, Larsen TH, Nordrehaug JE, Nygård OK, Sagen JV, Gudbrandsen OA, Dankel SN, Mellgren G. Visceral adiposity and metabolic syndrome after very high-fat and low-fat isocaloric diets: a randomized controlled trial. Am J Clin Nutr 2017; 105:85-99. [PMID: 27903520 DOI: 10.3945/ajcn.115.123463] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 10/28/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Different aspects of dietary pattern, including macronutrient and food profiles, may affect visceral fat mass and metabolic syndrome. OBJECTIVE We hypothesized that consuming energy primarily from carbohydrate or fat in diets with similar food profiles would differentially affect the ability to reverse visceral adiposity and metabolic syndrome. DESIGN Forty-six men (aged 30-50 y) with body mass index (in kg/m2) >29 and waist circumference >98 cm were randomly assigned to a very high-fat, low-carbohydrate (VHFLC; 73% of energy fat and 10% of energy carbohydrate) or low-fat, high-carbohydrate (LFHC; 30% of energy fat and 53% of energy carbohydrate) diet for 12 wk. The diets were equal in energy (8750 kJ/d), protein (17% of energy), and food profile, emphasizing low-processed, lower-glycemic foods. Fat mass was quantified with computed tomography imaging. RESULTS Recorded intake of carbohydrate and total and saturated fat in the LFHC and VHFLC groups were 51% and 11% of energy, 29% and 71% of energy, and 12% and 34% of energy, respectively, with no difference in protein and polyunsaturated fatty acids. Mean energy intake decreased by 22% and 14% in the LFHC and VHFLC groups. The diets similarly reduced waist circumference (11-13 cm), abdominal subcutaneous fat mass (1650-1850 cm3), visceral fat mass (1350-1650 cm3), and total body weight (11-12 kg). Both groups improved dyslipidemia, with reduced circulating triglycerides, but showed differential responses in total and low-density lipoprotein cholesterol (decreased in LFHC group only), and high-density lipoprotein cholesterol (increased in VHFLC group only). The groups showed similar reductions in insulin, insulin C-peptide, glycated hemoglobin, and homeostasis model assessment of insulin resistance. Notably, improvements in circulating metabolic markers in the VHFLC group mainly were observed first after 8 wk, in contrast to more acute and gradual effects in the LFHC group. CONCLUSIONS Consuming energy primarily as carbohydrate or fat for 3 mo did not differentially influence visceral fat and metabolic syndrome in a low-processed, lower-glycemic dietary context. Our data do not support the idea that dietary fat per se promotes ectopic adiposity and cardiometabolic syndrome in humans. This study was registered at clinicaltrials.gov as NCT01750021.
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Affiliation(s)
- Vivian L Veum
- Department of Clinical Science.,KG Jebsen Centre for Diabetes Research, Department of Clinical Science, and.,Hormone Laboratory and
| | - Johnny Laupsa-Borge
- Department of Clinical Science.,Hormone Laboratory and.,Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | | | - Espen Rostrup
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Terje H Larsen
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | | | - Ottar K Nygård
- Department of Clinical Science.,KG Jebsen Centre for Diabetes Research, Department of Clinical Science, and.,Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Jørn V Sagen
- Department of Clinical Science.,KG Jebsen Centre for Diabetes Research, Department of Clinical Science, and.,Hormone Laboratory and
| | | | - Simon N Dankel
- Department of Clinical Science, .,KG Jebsen Centre for Diabetes Research, Department of Clinical Science, and.,Hormone Laboratory and
| | - Gunnar Mellgren
- Department of Clinical Science, .,KG Jebsen Centre for Diabetes Research, Department of Clinical Science, and.,Hormone Laboratory and
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214
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Tanaka S, Hikita H, Tatsumi T, Sakamori R, Nozaki Y, Sakane S, Shiode Y, Nakabori T, Saito Y, Hiramatsu N, Tabata K, Kawabata T, Hamasaki M, Eguchi H, Nagano H, Yoshimori T, Takehara T. Rubicon inhibits autophagy and accelerates hepatocyte apoptosis and lipid accumulation in nonalcoholic fatty liver disease in mice. Hepatology 2016; 64:1994-2014. [PMID: 27637015 DOI: 10.1002/hep.28820] [Citation(s) in RCA: 245] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 08/13/2016] [Indexed: 12/11/2022]
Abstract
UNLABELLED Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver disease worldwide. It encompasses a spectrum ranging from simple steatosis to fatty liver with hepatocellular injury, termed nonalcoholic steatohepatitis. Recent studies have demonstrated hepatic autophagy being impaired in NAFLD. In the present study, we investigated the impact of Rubicon, a Beclin1-interacting negative regulator for autophagosome-lysosome fusion, in the pathogenesis of NAFLD. In HepG2 cells, BNL-CL2 cells, and murine primary hepatocytes, Rubicon was posttranscriptionally up-regulated by supplementation with saturated fatty acid palmitate. Up-regulation of Rubicon was associated with suppression of the late stage of autophagy, as evidenced by accumulation of both LC3-II and p62 expression levels as well as decreased autophagy flux. Its blockade by small interfering RNA attenuated autophagy impairment and reduced palmitate-induced endoplasmic reticulum stress, apoptosis, and lipid accumulation. Rubicon was also up-regulated in association with autophagy impairment in livers of mice fed a high-fat diet (HFD). Hepatocyte-specific Rubicon knockout mice generated by crossing Rubicon floxed mice with albumin-Cre transgenic mice did not produce any phenotypes on a normal diet. In contrast, on an HFD, they displayed significant improvement of both liver steatosis and injury as well as attenuation of both endoplasmic reticulum stress and autophagy impairment in the liver. In humans, liver tissues obtained from patients with NAFLD expressed significantly higher levels of Rubicon than those without steatosis. CONCLUSION Rubicon is overexpressed and plays a pathogenic role in NAFLD by accelerating hepatocellular lipoapoptosis and lipid accumulation, as well as inhibiting autophagy. Rubicon may be a novel therapeutic target for regulating NAFLD development and progression. (Hepatology 2016;64:1994-2014).
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Affiliation(s)
- Satoshi Tanaka
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hayato Hikita
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tomohide Tatsumi
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Ryotaro Sakamori
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yasutoshi Nozaki
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Sadatsugu Sakane
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yuto Shiode
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tasuku Nakabori
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yoshinobu Saito
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Naoki Hiramatsu
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Keisuke Tabata
- Department of Genetics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tsuyoshi Kawabata
- Department of Genetics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Maho Hamasaki
- Department of Genetics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hidetoshi Eguchi
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hiroaki Nagano
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tamotsu Yoshimori
- Department of Genetics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tetsuo Takehara
- Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Osaka, Japan
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215
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Croce AC, Ferrigno A, Di Pasqua LG, Berardo C, Piccolini VM, Bertone V, Bottiroli G, Vairetti M. Autofluorescence discrimination of metabolic fingerprint in nutritional and genetic fatty liver models. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 164:13-20. [DOI: 10.1016/j.jphotobiol.2016.09.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/09/2016] [Accepted: 09/10/2016] [Indexed: 12/21/2022]
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216
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Cheng X, Xi QY, Wei S, Wu D, Ye RS, Chen T, Qi QE, Jiang QY, Wang SB, Wang LN, Zhu XT, Zhang YL. Critical role of miR-125b in lipogenesis by targeting stearoyl-CoA desaturase-1 (SCD-1). J Anim Sci 2016; 94:65-76. [PMID: 26812313 DOI: 10.2527/jas.2015-9456] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Alteration of gene expression tightly regulates lipogenesis. Stearoyl-CoA desaturase-1 (SCD-1), a key enzyme in lipogenesis, catalyzes the conversion of SFA to MUFA, and inhibition of its activity impairs lipid synthesis. As posttranscriptional regulators, microRNAs are involved in many pathways of lipid metabolism; however, their effect on SCD-1 has not been reported. In this study, miR-125b was identified as a potential regulator of SCD-1 using bioinformatics analysis. Here, we validated SCD-1 as the target of miR-125b using a dual luciferase assay. During adipogenesis, a synthetic mimic or inhibitor was used to overexpress or reduce the expression of miR-125b in porcine adipocytes. Overexpression of miR-125b reduced the accumulation of lipid droplets and triglycerides concentration and repressed SCD-1 protein expression and MUFA composition. The inhibitor had the reverse effect. Small interfering RNA against tested in adipocytes further proved the direct correlation between miR-125b and SCD-1. Moreover, in vivo experiments in mice showed that injection of miR-125b expression vector decreased the hepatic triglycerides concentration relative to saline. This study indicated that miR-125b regulates lipogenesis by targeting SCD-1; therefore, miR-125b might be applied in therapy of lipid metabolism disorders.
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217
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Caligiuri A, Gentilini A, Marra F. Molecular Pathogenesis of NASH. Int J Mol Sci 2016; 17:ijms17091575. [PMID: 27657051 PMCID: PMC5037841 DOI: 10.3390/ijms17091575] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is the main cause of chronic liver disease in the Western world and a major health problem, owing to its close association with obesity, diabetes, and the metabolic syndrome. NASH progression results from numerous events originating within the liver, as well as from signals derived from the adipose tissue and the gastrointestinal tract. In a fraction of NASH patients, disease may progress, eventually leading to advanced fibrosis, cirrhosis and hepatocellular carcinoma. Understanding the mechanisms leading to NASH and its evolution to cirrhosis is critical to identifying effective approaches for the treatment of this condition. In this review, we focus on some of the most recent data reported on the pathogenesis of NASH and its fibrogenic progression, highlighting potential targets for treatment or identification of biomarkers of disease progression.
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Affiliation(s)
- Alessandra Caligiuri
- Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi di Firenze, Firenze 50121, Italy.
| | - Alessandra Gentilini
- Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi di Firenze, Firenze 50121, Italy.
| | - Fabio Marra
- Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi di Firenze, Firenze 50121, Italy.
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218
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Huang N, Yu Y, Qiao J. Dual role for the unfolded protein response in the ovary: adaption and apoptosis. Protein Cell 2016; 8:14-24. [PMID: 27638465 PMCID: PMC5233609 DOI: 10.1007/s13238-016-0312-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/01/2016] [Indexed: 02/06/2023] Open
Abstract
The endoplasmic reticulum (ER) is the principal organelle responsible for several specific cellular functions including synthesis and folding of secretory or membrane proteins, lipid metabolism, and Ca2+ storage. Different physiological as well as pathological stress conditions can, however, perturb ER homeostasis, giving rise to an accumulation of unfolded or misfolded proteins in the ER lumen, a condition termed ER stress. To deal with an increased folding demand, cells activate the unfolded protein response (UPR), which is initially protective but can become detrimental if ER stress is severe and prolonged. Accumulating evidence demonstrates a link between the UPR and ovarian development and function, including follicular growth and maturation, follicular atresia, and corpus luteum biogenesis. Additionally, ER stress and the UPR may also play an important role in the ovary under pathological conditions. Understanding the molecular mechanisms related to the dual role of unfolded protein response in the ovarian physiology and pathology may reveal the pathogenesis of some reproductive endocrine diseases and provide a new guidance to improve the assisted reproductive technology. Here we review the current literature and discuss concepts and progress in understanding the UPR, and we also analyze the role of ER stress and the UPR in the ovary.
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Affiliation(s)
- Ning Huang
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology and Key Laboratory of Assisted Reproduction, Ministry of Education, Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China
| | - Yang Yu
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology and Key Laboratory of Assisted Reproduction, Ministry of Education, Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China.
| | - Jie Qiao
- Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology and Key Laboratory of Assisted Reproduction, Ministry of Education, Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China.
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219
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Dettlaff-Pokora A, Sledzinski T, Swierczynski J. Upregulation of Pnpla2 and Abhd5 and downregulation of G0s2 gene expression in mesenteric white adipose tissue as a potential reason for elevated concentration of circulating NEFA after removal of retroperitoneal, epididymal, and inguinal adipose tissue. Mol Cell Biochem 2016; 422:21-29. [PMID: 27590244 PMCID: PMC5055569 DOI: 10.1007/s11010-016-2800-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 08/25/2016] [Indexed: 02/06/2023]
Abstract
Elevated concentrations of circulating non-esterified fatty acids (NEFA) were reported in (a) humans with lipodystrophy, (b) humans following bariatric surgery, and (c) transgenic mice with reduced amounts of adipose tissue. Paradoxically, these findings suggest that the reduction of adipose tissue mass is associated with elevated circulating NEFA concentrations. To explain a molecular background of this phenomenon, we analyzed the effects of surgical removal of inguinal, epididymal, and retroperitoneal white adipose tissue (WAT) on (a) circulating NEFA concentrations, (b) expression of Pnpla2, a gene that encodes adipose triglyceride lipase (ATGL), genes encoding abhydrolase domain containing 5 (ABHD5) and G0/G1 switch 2 (G0S2), i.e., a coactivator and inhibitor of ATGL, respectively, and (c) expression of Lipe gene coding hormone-sensitive lipase (HSL) in mesenteric WAT. Reduction of adipose tissue mass resulted in an increase in circulating NEFA concentration, which was associated with (a) an increase in the expressions of Pnpla2 and Abhd5, (b) decrease in G0s2 expression, and (c) upregulation of Lipe expression, all measured on both mRNA and protein levels in mesenteric WAT of male rats. The rate of lipolysis in mesenteric WAT explants and isolated adipocytes from lipectomized rats was significantly higher than that from the controls. In conclusion, upregulation of Pnpla2 expression and activation of ATGL (due to an increase in ABHD5 and decrease in G0S2 levels), as well as a coordinated interplay of these genes with Lipe in mesenteric WAT, contribute, at least in part, to an increase in the concentration of circulating NEFA in rats with reduced fat mass.
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Affiliation(s)
| | - Tomasz Sledzinski
- Department of Pharmaceutical Biochemistry, Medical University of Gdansk, Dębinki 1, 80-211, Gdansk, Poland
| | - Julian Swierczynski
- Department of Biochemistry, Medical University of Gdansk, Dębinki 1, 80-211, Gdansk, Poland.
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220
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Walenbergh SMA, Shiri-Sverdlov R. Cholesterol is a significant risk factor for non-alcoholic steatohepatitis. Expert Rev Gastroenterol Hepatol 2016; 9:1343-6. [PMID: 26395315 DOI: 10.1586/17474124.2015.1092382] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Non-alcoholic steatohepatitis (NASH) is characterized by hepatic lipid accumulation (steatosis) and inflammation (steatohepatitis). Currently, the exact underlying mechanisms leading to hepatic inflammation remain incompletely understood and therefore therapy options are poor. Analogous to the predominant metabolic risk factor for the metabolic syndrome, NASH patients often display diet-induced dyslipidemia and are therefore also at high risk for cardiovascular disease. Higher lipid levels, in general, are also widely associated with the production of reactive oxygen species during oxidation. However, the exact contribution of the specific type of lipids to hepatic inflammation still remains unclear. In this editorial, we aim to show that cholesterol, in addition to triglycerides and free fatty acids, is an important risk factor in NASH disease pathogenesis. Developing a better understanding of the contribution of lipids underlying NASH pathogenesis is essential for creating effective therapies against this prevalent disease.
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Affiliation(s)
- Sofie M A Walenbergh
- a Department of Molecular Genetics, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - Ronit Shiri-Sverdlov
- a Department of Molecular Genetics, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
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221
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222
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Buzzetti E, Pinzani M, Tsochatzis EA. The multiple-hit pathogenesis of non-alcoholic fatty liver disease (NAFLD). Metabolism 2016; 65:1038-48. [PMID: 26823198 DOI: 10.1016/j.metabol.2015.12.012] [Citation(s) in RCA: 1836] [Impact Index Per Article: 229.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/14/2015] [Accepted: 12/17/2015] [Indexed: 02/06/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent and represents a growing challenge in terms of prevention and treatment. Despite its high prevalence, only a small minority of affected patients develops inflammation and subsequently fibrosis and chronic liver disease, while most of them only exhibit simple steatosis. In this context, the full understanding of the mechanisms underlying the development of NAFLD and non-alcoholic steatohepatitis (NASH) is of extreme importance; despite advances in this field, knowledge on the pathogenesis of NAFLD is still incomplete. The 'two-hit' hypothesis is now obsolete, as it is inadequate to explain the several molecular and metabolic changes that take place in NAFLD. The "multiple hit" hypothesis considers multiple insults acting together on genetically predisposed subjects to induce NAFLD and provides a more accurate explanation of NAFLD pathogenesis. Such hits include insulin resistance, hormones secreted from the adipose tissue, nutritional factors, gut microbiota and genetic and epigenetic factors. In this article, we review the factors that form this hypothesis.
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Affiliation(s)
- Elena Buzzetti
- UCL Institute for Liver and Digestive Health and Sheila Sherlock Liver Unit, Royal Free Hospital and UCL, London, UK
| | - Massimo Pinzani
- UCL Institute for Liver and Digestive Health and Sheila Sherlock Liver Unit, Royal Free Hospital and UCL, London, UK
| | - Emmanuel A Tsochatzis
- UCL Institute for Liver and Digestive Health and Sheila Sherlock Liver Unit, Royal Free Hospital and UCL, London, UK.
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223
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Mota M, Banini BA, Cazanave SC, Sanyal AJ. Molecular mechanisms of lipotoxicity and glucotoxicity in nonalcoholic fatty liver disease. Metabolism 2016; 65:1049-61. [PMID: 26997538 PMCID: PMC4931958 DOI: 10.1016/j.metabol.2016.02.014] [Citation(s) in RCA: 356] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 02/05/2016] [Accepted: 02/23/2016] [Indexed: 12/21/2022]
Abstract
The exposure of hepatocytes to high concentrations of lipids and carbohydrates and the ensuing hepatocellular injury are termed lipotoxicity and glucotoxicity, respectively. A common denominator is metabolic derangement, especially in regards to intracellular energy homeostasis, which is brought on by glucose intolerance and insulin resistance in tissues. In this review, we highlight the lipids and carbohydrates that provoke hepatocyte injury and the mechanisms involved in lipotoxicity and glucotoxicity, including endoplasmic reticulum stress, oxidative stress and mitochondrial impairment. Through upregulation of proteins involved in various pathways including PKR-like ER kinase (PERK), CCAAT/enhancer-binding homologous protein (CHOP), c-Jun NH2-terminal kinase-1 (JNK), Bcl-2 interacting mediator (BIM), p53 upregulated modulator of apoptosis (PUMA), and eventually caspases, hepatocytes in lipotoxic states ultimately undergo apoptosis. The protective role of certain lipids and possible targets for pharmacological therapy are explored. Finally, we discuss the role of high fructose and glucose diets in contributing to organelle impairment and poor glucose transport mechanisms, which perpetuate hyperglycemia and hyperlipidemia by shunting of excess carbohydrates into lipogenesis.
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Affiliation(s)
- Manoela Mota
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
| | - Bubu A Banini
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Sophie C Cazanave
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Arun J Sanyal
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
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224
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Houben T, Brandsma E, Walenbergh SMA, Hofker MH, Shiri-Sverdlov R. Oxidized LDL at the crossroads of immunity in non-alcoholic steatohepatitis. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:416-429. [PMID: 27472963 DOI: 10.1016/j.bbalip.2016.07.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 07/01/2016] [Accepted: 07/21/2016] [Indexed: 02/08/2023]
Abstract
Non-alcoholic steatohepatitis (NASH) is viewed as the hepatic manifestation of the metabolic syndrome and is a condition hallmarked by lipid accumulation in the liver (steatosis) along with inflammation (hepatitis). Currently, the etiology and mechanisms leading to obesity-induced hepatic inflammation are not clear and, as a consequence, strategies to diagnose or treat NASH in an accurate manner do not exist. In the current review, we put forward the concept of oxidized lipids as a significant risk factor for NASH. We will focus on the contribution of the different types of oxidized lipids as part of the oxidized low-density lipoprotein (oxLDL) to the hepatic inflammatory response. Furthermore, we will elaborate on the underlying mechanisms linking oxLDL to inflammatory responses in the liver and on how these cascades can be used as therapeutic targets to combat NASH. This article is part of a Special Issue entitled: Lipid modification and lipid peroxidation products in innate immunity and inflammation edited by Christoph J. Binder.
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Affiliation(s)
- T Houben
- Department of Molecular Genetics, Maastricht University, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht, the Netherlands
| | - E Brandsma
- Molecular Genetics Section, Department of Pediatrics, University Medical Center Groningen, University of Groningen, the Netherlands
| | - S M A Walenbergh
- Department of Molecular Genetics, Maastricht University, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht, the Netherlands
| | - M H Hofker
- Molecular Genetics Section, Department of Pediatrics, University Medical Center Groningen, University of Groningen, the Netherlands
| | - R Shiri-Sverdlov
- Department of Molecular Genetics, Maastricht University, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht, the Netherlands.
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225
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Bashiri A, Nesan D, Tavallaee G, Sue-Chue-Lam I, Chien K, Maguire GF, Naples M, Zhang J, Magomedova L, Adeli K, Cummins CL, Ng DS. Cellular cholesterol accumulation modulates high fat high sucrose (HFHS) diet-induced ER stress and hepatic inflammasome activation in the development of non-alcoholic steatohepatitis. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:594-605. [DOI: 10.1016/j.bbalip.2016.04.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 04/05/2016] [Accepted: 04/11/2016] [Indexed: 01/19/2023]
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226
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Liu X, Burhans MS, Flowers MT, Ntambi JM. Hepatic oleate regulates liver stress response partially through PGC-1α during high-carbohydrate feeding. J Hepatol 2016; 65:103-112. [PMID: 26976120 PMCID: PMC4939798 DOI: 10.1016/j.jhep.2016.03.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 02/24/2016] [Accepted: 03/01/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUND & AIMS High-carbohydrate diets contribute to the development of liver stress and fatty liver disease. While saturated fatty acids are known to induce liver stress, the role of monounsaturated fatty acids (MUFA), synthesized by the stearoyl-CoA desaturase (SCD) family of enzymes, in regulation of liver function during lipogenic dietary conditions remains largely unknown. The major products of SCD-catalyzed reactions are oleate (18:1n-9) and palmitoleate (16:1n-7). METHODS We generated mouse models with restricted exogenous MUFA supply and reduced endogenous MUFA synthesis, in which SCD1 global knockout (GKO) or liver-specific knockout (LKO) mice were fed a lipogenic high-sucrose very low-fat (HSVLF) or high-carbohydrate (HC) diet. In a gain-of-function context, we introduced liver-specific expression of either human SCD5, which synthesizes 18:1n-9, or mouse Scd3, which synthesizes 16:1n-7, into SCD1 GKO mice and fed the HSVLF diet. RESULTS Lipogenic high-carbohydrate diets induced hepatic endoplasmic reticulum (ER) stress and inflammation in SCD1 GKO and LKO mice. Dietary supplementation with 18:1n-9, but not 18:0, prevented the HSVLF diet-induced hepatic ER stress and inflammation in SCD1 LKO mice, while hepatic SCD5, but not Scd3, expression reduced the ER stress and inflammation in GKO mice. Additional experiments revealed liver-specific deletion of the transcriptional coactivator PGC-1α reduced hepatic inflammatory and ER stress response gene expression in SCD1 LKO mice. CONCLUSIONS Our results demonstrate an indispensable role of hepatic oleate in protection against lipogenic diet-induced hepatic injury, and PGC-1α potentiates the ER stress response under conditions of restricted dietary oleate coupled to reduced capacity of endogenous hepatic oleate synthesis. LAY SUMMARY Susceptibility to metabolic dysfunction is influenced by genetic and environmental factors. In this study we show that modulation of two genes regulates the liver response, including ER stress and inflammation, to a high-carbohydrate low-fat diet. We reveal that hepatic availability of oleate, a monounsaturated fatty acid, is important for maintenance of liver health.
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Affiliation(s)
- Xueqing Liu
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Maggie S. Burhans
- Department of Nutritional Sciences, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Matthew T. Flowers
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - James M. Ntambi
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA,Department of Nutritional Sciences, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA,Corresponding author. Address: Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA. Tel.: +1 6082399074. (J.M. Ntambi)
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New insights into salvianolic acid A action: Regulation of the TXNIP/NLRP3 and TXNIP/ChREBP pathways ameliorates HFD-induced NAFLD in rats. Sci Rep 2016; 6:28734. [PMID: 27345365 PMCID: PMC4922017 DOI: 10.1038/srep28734] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 06/08/2016] [Indexed: 12/30/2022] Open
Abstract
Salvianolic acid A (SalA), one of the most efficacious polyphenol compounds extracted from Radix Salvia miltiorrhiza (Danshen), has been shown to possess many potential pharmacological activities. This study aimed to investigate whether SalA has hepatoprotective effects against high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) and to further explore the mechanism underlying this process. SalA treatment significantly attenuated HFD-induced obesity and liver injury, and markedly decreased lipid accumulation in HFD-fed rat livers. Moreover, SalA treatment ameliorated HFD-induced hepatic inflammation and oxidative stress by decreasing hepatotoxic levels of cytokines, suppressing the overproduction of reactive oxygen species (ROS) and methane dicarboxylic aldehyde (MDA) and preventing the decreased expression of superoxide dismutase (SOD). Importantly, SalA reversed the HFD- or palmitic acid (PA)-induced activation of the NLRP3 inflammasome, the nuclear translocation of ChREBP and the up-regulation of FAS, and these effects were accompanied by TXNIP down-regulation. However, TXNIP siRNA treatment partially abrogated the above-mentioned effects of SalA in PA-treated HepG2 cells. Together, our results demonstrated, for the first time, that SalA protects against HFD-induced NAFLD by ameliorating hepatic lipid accumulation and inflammation, and these protective effects may partially due to regulation of the TXNIP/NLRP3 and TXNIP/ChREBP pathways.
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Hamlin AN, Basford JE, Jaeschke A, Hui DY. LRP1 Protein Deficiency Exacerbates Palmitate-induced Steatosis and Toxicity in Hepatocytes. J Biol Chem 2016; 291:16610-9. [PMID: 27317662 DOI: 10.1074/jbc.m116.717744] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Indexed: 01/21/2023] Open
Abstract
LRP1 (LDL receptor-related protein-1) is a ubiquitous receptor with both cell signaling and ligand endocytosis properties. In the liver, LRP1 serves as a chylomicron remnant receptor and also participates in the transport of extracellular cathepsin D to the lysosome for prosaposin activation. The current study showed that in comparison with wild type mice, hepatocyte-specific LRP1 knock-out (hLrp1(-/-)) mice were more susceptible to fasting-induced lipid accumulation in the liver. Primary hepatocytes isolated from hLrp1(-/-) mice also accumulated more intracellular lipids and experienced higher levels of endoplasmic reticulum (ER) stress after palmitate treatment compared with similarly treated hLrp1(+/+) hepatocytes. Palmitate-treated hLrp1(-/-) hepatocytes displayed similar LC3-II levels, but the levels of p62 were elevated in comparison with palmitate-treated hLrp1(+/+) hepatocytes, suggesting that the elevated lipid accumulation in LRP1-defective hepatocytes was not due to defects in autophagosome formation but was due to impairment of lipophagic lipid hydrolysis in the lysosome. Additional studies showed increased palmitate-induced oxidative stress, mitochondrial and lysosomal permeability, and cell death in hLrp1(-/-) hepatocytes. Importantly, the elevated cell death and ER stress observed in hLrp1(-/-) hepatocytes were abrogated by E64D treatment, whereas inhibiting ER stress diminished cell death but not lysosomal permeabilization. Taken together, these results documented that LRP1 deficiency in hepatocytes promotes lipid accumulation and lipotoxicity through lysosomal-mitochondrial permeabilization and ER stress that ultimately result in cell death. Hence, LRP1 dysfunction may be a major risk factor in fatty liver disease progression.
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Affiliation(s)
| | - Joshua E Basford
- Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio 45237
| | - Anja Jaeschke
- Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio 45237
| | - David Y Hui
- Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio 45237
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Knockdown of triglyceride synthesis does not enhance palmitate lipotoxicity or prevent oleate-mediated rescue in rat hepatocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1005-1014. [PMID: 27249207 DOI: 10.1016/j.bbalip.2016.05.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 05/14/2016] [Accepted: 05/26/2016] [Indexed: 12/14/2022]
Abstract
Experiments in a variety of cell types, including hepatocytes, consistently demonstrate the acutely lipotoxic effects of saturated fatty acids, such as palmitate (PA), but not unsaturated fatty acids, such as oleate (OA). PA+OA co-treatment fully prevents PA lipotoxicity through mechanisms that are not well defined but which have been previously attributed to more efficient esterification and sequestration of PA into triglycerides (TGs) when OA is abundant. However, this hypothesis has never been directly tested by experimentally modulating the relative partitioning of PA/OA between TGs and other lipid fates in hepatocytes. In this study, we found that addition of OA to PA-treated hepatocytes enhanced TG synthesis, reduced total PA uptake and PA lipid incorporation, decreased phospholipid saturation and rescued PA-induced ER stress and lipoapoptosis. Knockdown of diacylglycerol acyltransferase (DGAT), the rate-limiting step in TG synthesis, significantly reduced TG accumulation without impairing OA-mediated rescue of PA lipotoxicity. In both wild-type and DGAT-knockdown hepatocytes, OA co-treatment significantly reduced PA lipid incorporation and overall phospholipid saturation compared to PA-treated hepatocytes. These data indicate that OA's protective effects do not require increased conversion of PA into inert TGs, but instead may be due to OA's ability to compete against PA for cellular uptake and/or esterification and, thereby, normalize the composition of cellular lipids in the presence of a toxic PA load.
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The Pathogenesis of Nonalcoholic Fatty Liver Disease: Interplay between Diet, Gut Microbiota, and Genetic Background. Gastroenterol Res Pract 2016; 2016:2862173. [PMID: 27247565 PMCID: PMC4876215 DOI: 10.1155/2016/2862173] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/14/2016] [Indexed: 02/07/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world, and it comprises a spectrum of hepatic abnormalities from simple hepatic steatosis to steatohepatitis, fibrosis, cirrhosis, and liver cancer. While the pathogenesis of NAFLD remains incompletely understood, a multihit model has been proposed that accommodates causal factors from a variety of sources, including intestinal and adipose proinflammatory stimuli acting on the liver simultaneously. Prior cellular and molecular studies of patient and animal models have characterized several common pathogenic mechanisms of NAFLD, including proinflammation cytokines, lipotoxicity, oxidative stress, and endoplasmic reticulum stress. In recent years, gut microbiota has gained much attention, and dysbiosis is recognized as a crucial factor in NAFLD. Moreover, several genetic variants have been identified through genome-wide association studies, particularly rs738409 (Ile748Met) in PNPLA3 and rs58542926 (Glu167Lys) in TM6SF2, which are critical risk alleles of the disease. Although a high-fat diet and inactive lifestyles are typical risk factors for NAFLD, the interplay between diet, gut microbiota, and genetic background is believed to be more important in the development and progression of NAFLD. This review summarizes the common pathogenic mechanisms, the gut microbiota relevant mechanisms, and the major genetic variants leading to NAFLD and its progression.
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Zhao Q, Guo Z, Deng W, Fu S, Zhang C, Chen M, Ju W, Wang D, He X. Calpain 2-mediated autophagy defect increases susceptibility of fatty livers to ischemia-reperfusion injury. Cell Death Dis 2016; 7:e2186. [PMID: 27077802 PMCID: PMC4855654 DOI: 10.1038/cddis.2016.66] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Revised: 02/24/2016] [Accepted: 02/26/2016] [Indexed: 12/17/2022]
Abstract
Hepatic steatosis is associated with significant morbidity and mortality after liver resection and transplantation. This study focuses on the role of autophagy in regulating sensitivity of fatty livers to ischemia and reperfusion (I/R) injury. Quantitative immunohistochemistry conducted on human liver allograft biopsies showed that, the reduction of autophagy markers LC3 and Beclin-1 at 1 h after reperfusion, was correlated with hepatic steatosis and poor survival of liver transplant recipients. In animal studies, western blotting and confocal imaging analysis associated the increase in sensitivity to I/R injury with low autophagy activity in fatty livers. Screening of autophagy-related proteins showed that Atg3 and Atg7 expression levels were marked decreased, whereas calpain 2 expression was upregulated during I/R in fatty livers. Calpain 2 inhibition or knockdown enhanced autophagy and suppressed cell death. Further point mutation experiments revealed that calpain 2 cleaved Atg3 and Atg7 at Atg3Δ92-97 and Atg7Δ344-349, respectively. In vivo and in vitro overexpression of Atg3 or Atg7 enhanced autophagy and suppressed cell death after I/R in fatty livers. Collectively, calpain 2-mediated degradation of Atg3 and Atg7 in fatty livers increases their sensitivity to I/R injury. Increasing autophagy may ameliorate fatty liver damage and represent a valuable method to expand the liver donor pool.
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Affiliation(s)
- Q Zhao
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Z Guo
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - W Deng
- Biotherapy Department, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - S Fu
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - C Zhang
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - M Chen
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - W Ju
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - D Wang
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - X He
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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Dossi CG, Tapia GS, González-Mañán D, D’Espessailles A. n-3 LCPUFA in the reversal of hepatic steatosis: the role of ACOX and CAT-1. GRASAS Y ACEITES 2016. [DOI: 10.3989/gya.0886152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Lipid deposition in liver cells: The influence of short form augmenter of liver regeneration. Clin Res Hepatol Gastroenterol 2016; 40:186-94. [PMID: 26476698 DOI: 10.1016/j.clinre.2015.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 07/11/2015] [Accepted: 07/15/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND OBJECTIVE The short form augmenter of liver regeneration (sfALR) is a novel human hepatotrophic growth factor. The aim of this study was to investigate the potential role of sfALR in NAFLD. METHODS The free fatty acids (FFA) induced lipid accumulation in mouse liver parenchymal cells was examined by Oil Red O staining and triglyceride level determination. The cell cycle was determined by flow cytometry and the proliferation was assessed by CCK8. The expression levels of gfer, miR-122, srebp-1c, fas, dgat2, acc1 and Lrp1B were assessed by quantitative real-time PCR. Furthermore, the MAPK pathway was detected by western blot. RESULTS The results showed that sfALR could alleviate the lipid accumulation in mice both in vivo and in vitro. sfALR relieved the proliferation inhibition and G2 arrest of mouse liver parenchymal cells induced by FFAs. Free fatty acids affected gfer expression in a time-and dose-dependent way. And sfALR suppressed JNK activation, increased miR-122 level and reduced fatty acid synthesis-related gene expression. CONCLUSION These findings suggested that sfALR could alleviate the severity of fatty liver in mice.
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Impact of anti-inflammatory nutrients on obesity-associated metabolic-inflammation from childhood through to adulthood. Proc Nutr Soc 2016; 75:115-24. [DOI: 10.1017/s0029665116000070] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Obesity-related metabolic conditions such as insulin resistance (IR), type 2 diabetes and CVD share a number of pathological features, one of which is metabolic-inflammation. Metabolic-inflammation results from the infiltration of immune cells into the adipose tissue, driving a pro-inflammatory environment, which can induce IR. Furthermore, resolution of inflammation, an active process wherein the immune system counteracts pro-inflammatory states, may be dysregulated in obesity. Anti-inflammatory nutritional interventions have focused on attenuating this pro-inflammatory environment. Furthermore, with inherent variability among individuals, establishing at-risk populations who respond favourably to nutritional intervention strategies is important. This review will focus on chronic low-grade metabolic-inflammation, resolution of inflammation and the putative role anti-inflammatory nutrients have as a potential therapy. Finally, in the context of personalised nutrition, the approaches used in defining individuals who respond favourably to nutritional interventions will be highlighted. With increasing prevalence of obesity in younger people, age-dependent biological processes, preventative strategies and therapeutic options are important to help protect against development of obesity-associated co-morbidities.
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236
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Chen YJ, Wallig MA, Jeffery EH. Dietary Broccoli Lessens Development of Fatty Liver and Liver Cancer in Mice Given Diethylnitrosamine and Fed a Western or Control Diet. J Nutr 2016; 146:542-50. [PMID: 26865652 PMCID: PMC4763488 DOI: 10.3945/jn.115.228148] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/07/2016] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The high-fat and high-sugar Westernized diet that is popular worldwide is associated with increased body fat accumulation, which has been related to the development of nonalcoholic fatty liver disease (NAFLD). Without treatment, NAFLD may progress to hepatocellular carcinoma (HCC), a cancer with a high mortality rate. The consumption of broccoli in the United States has greatly increased in the last 2 decades. Epidemiologic studies show that incorporating brassica vegetables into the daily diet lowers the risk of several cancers, although, to our knowledge, this is the first study to evaluate HCC prevention through dietary broccoli. OBJECTIVE We aimed to determine the impact of dietary broccoli on hepatic lipid metabolism and the progression of NAFLD to HCC. Our hypothesis was that broccoli decreases both hepatic lipidosis and the development of HCC in a mouse model of Western diet-enhanced liver cancer. METHODS Adult 5-wk-old male B6C3F1 mice received a control diet (AIN-93M) or a Western diet (high in lard and sucrose, 19% and 31%, wt:wt, respectively), with or without freeze-dried broccoli (10%, wt:wt). Starting the following week, mice were treated once per week with diethylnitrosamine (DEN; 45 mg/kg body weight intraperitoneally at ages 6, 7, 8, 10, 11, and 12 wk). Hepatic gene expression, lipidosis, and tumor outcomes were analyzed 6 mo later, when mice were 9 mo old. RESULTS Mice receiving broccoli exhibited lower hepatic triglycerides (P < 0.001) and NAFLD scores (P < 0.0001), decreased plasma alanine aminotransferase (P < 0.0001), suppressed activation of hepatic CD68(+) macrophages (P < 0.0001), and slowed initiation and progression of hepatic neoplasm. Hepatic Cd36 was downregulated by broccoli feeding (P = 0.006), whereas microsomal triglyceride transfer protein was upregulated (P = 0.045), supporting the finding that dietary broccoli decreased hepatic triglycerides. CONCLUSION Long-term consumption of whole broccoli countered both NAFLD development enhanced by a Western diet and hepatic tumorigenesis induced by DEN in male B6C3F1 mice.
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Affiliation(s)
- Yung-Ju Chen
- Departments of Food Science and Human Nutrition and
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Black PN, Ahowesso C, Montefusco D, Saini N, DiRusso CC. Fatty Acid Transport Proteins: Targeting FATP2 as a Gatekeeper Involved in the Transport of Exogenous Fatty Acids. MEDCHEMCOMM 2016; 7:612-622. [PMID: 27446528 DOI: 10.1039/c6md00043f] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The fatty acid transport proteins (FATP) are classified as members of the Solute Carrier 27 (Slc27) family of proteins based on their ability to function in the transport of exogenous fatty acids. These proteins, when localized to the plasma membrane or at intracellular membrane junctions with the endoplasmic reticulum, function as a gate in the regulated transport of fatty acids and thus represent a therapeutic target to delimit the acquisition of fatty acids that contribute to disease as in the case of fatty acid overload. To date, FATP1, FATP2, and FATP4 have been used as targets in the selection of small molecule inhibitors with the goal of treating insulin resistance and attenuating dietary absorption of fatty acids. Several studies targeting FATP1 and FATP4 were based on the intrinsic acyl CoA synthetase activity of these proteins and not on transport directly. While several classes of compounds were identified as potential inhibitors of fatty acid transport, in vivo studies using a mouse model failed to provide evidence these compounds were effective in blocking or attenuating fatty acid transport. Studies targeting FATP2 employed a naturally occurring splice variant, FATP2b, which lacks intrinsic acyl CoA synthetase due to the deletion of exon 3, yet is fully functional in fatty acid transport. These studies identified two compounds, 5'-bromo-5-phenyl-spiro[3H-1,3,4-thiadiazole-2,3'-indoline]-2'-one), now referred to as Lipofermata, and 2-benzyl-3-(4-chlorophenyl)-5-(4-nitrophenyl)pyrazolo[1,5-a]pyrimidin-7(4H)-one, now called Grassofermata, that are effective fatty acid transport inhibitors both in vitro using a series of model cell lines and in vivo using a mouse model.
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Affiliation(s)
- Paul N Black
- Department of Biochemistry, University of Nebraska, Lincoln, NE
| | | | | | - Nipun Saini
- Department of Biochemistry, University of Nebraska, Lincoln, NE
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Syed R, Shibata NM, Kharbanda KK, Su RJ, Olson K, Yokoyama A, Rutledge JC, Chmiel KJ, Kim K, Halsted CH, Medici V. Effects of Nonpurified and Choline Supplemented or Nonsupplemented Purified Diets on Hepatic Steatosis and Methionine Metabolism in C3H Mice. Metab Syndr Relat Disord 2016; 14:202-9. [PMID: 26881897 DOI: 10.1089/met.2015.0147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Previous studies indicated that nonpurified and purified commercially available control murine diets have different metabolic effects with potential consequences on hepatic methionine metabolism and liver histology. METHODS We compared the metabolic and histological effects of commercial nonpurified (13% calories from fat; 57% calories from carbohydrates with 38 grams/kg of sucrose) and purified control diets (12% calories from fat; 69% calories from carbohydrates with ∼500 grams/kg of sucrose) with or without choline supplementation administered to C3H mice with normal lipid and methionine metabolism. Diets were started 2 weeks before mating, continued through pregnancy and lactation, and continued in offspring until 24 weeks of age when we collected plasma and liver tissue to study methionine and lipid metabolism. RESULTS Compared to mice fed nonpurified diets, the liver/body weight ratio was significantly higher in mice fed either purified diet, which was associated with hepatic steatosis and inflammation. Plasma alanine aminotransferase levels were higher in mice receiving the purified diets. The hepatic S-adenosylmethionine (SAM)/S-adenosylhomocysteine (SAH) ratio was higher in female mice fed purified compared to nonpurified diet (4.6 ± 2 vs. 2.8 ± 1.9; P < 0.05). Choline supplementation was associated with improvement of some parameters of lipid and methionine metabolism in mice fed purified diets. CONCLUSIONS Standard nonpurified and purified diets have significantly different effects on development of steatosis in control mice. These findings can help in development of animal models of fatty liver and in choosing appropriate laboratory control diets for control animals.
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Affiliation(s)
- Raisa Syed
- 1 Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of California , Davis, Sacramento, California
| | - Noreene M Shibata
- 1 Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of California , Davis, Sacramento, California
| | - Kusum K Kharbanda
- 2 Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System , Omaha, Nebraska
| | - Ruijun J Su
- 3 Department of Pathology and Laboratory Medicine, University of California , Davis, Sacramento, California
| | - Kristin Olson
- 3 Department of Pathology and Laboratory Medicine, University of California , Davis, Sacramento, California
| | - Amy Yokoyama
- 4 Division of Cardiovascular Medicine, Department of Internal Medicine, University of California , Davis, Davis, California
| | - John C Rutledge
- 4 Division of Cardiovascular Medicine, Department of Internal Medicine, University of California , Davis, Davis, California
| | - Kenneth J Chmiel
- 1 Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of California , Davis, Sacramento, California
| | - Kyoungmi Kim
- 5 Division of Biostatistics, Department of Public Health Sciences, University of California , Davis, Davis, California
| | - Charles H Halsted
- 1 Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of California , Davis, Sacramento, California
| | - Valentina Medici
- 1 Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of California , Davis, Sacramento, California
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Korean Pine Nut Oil Attenuated Hepatic Triacylglycerol Accumulation in High-Fat Diet-Induced Obese Mice. Nutrients 2016; 8:nu8010059. [PMID: 26805879 PMCID: PMC4728670 DOI: 10.3390/nu8010059] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 01/06/2016] [Accepted: 01/15/2016] [Indexed: 02/06/2023] Open
Abstract
Korean pine nut oil (PNO) has been reported to influence weight gain and lipid metabolism. We examined whether PNO replacement in a high-fat diet (HFD) can ameliorate HFD-induced hepatic steatosis. Five-week-old male C57BL mice were fed control diets containing 10% of the energy from fat from PNO or soybean oil (SBO) (PC, SC) or HFDs with 45% of the energy from fat, with 10% from PNO or SBO and 35% from lard (PHFD, SHFD), for 12 weeks. Body weight gain and amount of white adipose tissue were lower in PHFD (10% and 18% lower, respectively) compared with SHFD. Hepatic triacylglycerol (TG) level was significantly lower in PHFD than the SHFD (26% lower). PNO consumption upregulated hepatic ACADL mRNA levels. The hepatic PPARG mRNA level was lower in the PC than in the SC. Expression of the sirtuin (SIRT) 3 protein in white adipose tissue was down-regulated in the SHFD and restored in the PHFD to the level in the lean control mice. SIRT 3 was reported to be upregulated under conditions of caloric restriction (CR) and plays a role in regulating mitochondrial function. PNO consumption resulted in lower body fat and hepatic TG accumulation in HFD-induced obesity, which seemed to be associated with the CR-mimetic response.
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Yi HW, Ma YX, Wang XN, Wang CF, Lu J, Cao W, Wu XD. Ethanol promotes saturated fatty acid-induced hepatoxicity through endoplasmic reticulum (ER) stress response. Chin J Nat Med 2016; 13:250-6. [PMID: 25908621 DOI: 10.1016/s1875-5364(15)30011-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Indexed: 12/31/2022]
Abstract
Serum palmitic acid (PA), a type of saturated fatty acid, causes lipid accumulation and induces toxicity in hepatocytes. Ethanol (EtOH) is metabolized by the liver and induces hepatic injury and inflammation. Herein, we analyzed the effects of EtOH on PA-induced lipotoxicity in the liver. Our results indicated that EtOH aggravated PA-induced apoptosis and lipid accumulation in primary rat hepatocytes in dose-dependent manner. EtOH intensified PA-caused endoplasmic reticulum (ER) stress response in vitro and in vivo, and the expressions of CHOP, ATF4, and XBP-1 in nucleus were significantly increased. EtOH also increased PA-caused cleaved caspase-3 in cytoplasm. In wild type and CHOP(-/-) mice treated with EtOH and high fat diet (HFD), EtOH worsened the HFD-induced liver injury and dyslipidemia, while CHOP knockout blocked toxic effects of EtOH and PA. Our study suggested that targeting UPR-signaling pathways is a promising, novel approach to reducing EtOH and saturated fatty acid-induced metabolic complications.
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Affiliation(s)
- Hong-Wei Yi
- Department of Pharmacology, Medical School, Southeast University, Nanjing 210009, China; State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.
| | - Yu-Xiang Ma
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Xiao-Ning Wang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Cui-Fen Wang
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV 25755, USA
| | - Jian Lu
- Department of Pharmacology, Medical School, Southeast University, Nanjing 210009, China
| | - Wei Cao
- Department of Pharmacology, Medical School, Southeast University, Nanjing 210009, China
| | - Xu-Dong Wu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.
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Liu Z, Li P, Zhao ZH, Zhang Y, Ma ZM, Wang SX. Vitamin B6 Prevents Endothelial Dysfunction, Insulin Resistance, and Hepatic Lipid Accumulation in Apoe (-/-) Mice Fed with High-Fat Diet. J Diabetes Res 2016; 2016:1748065. [PMID: 26881239 PMCID: PMC4735993 DOI: 10.1155/2016/1748065] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 10/08/2015] [Accepted: 10/21/2015] [Indexed: 12/22/2022] Open
Abstract
Backgrounds. VitB6 deficiency has been associated with a number of adverse health effects. However, the effects of VitB6 in metabolic syndrome are poorly understood. Methods. VitB6 (50 mg/kg/day) was given to Apoe (-/-) mice with hkdigh-fat diet (HFD) for 8 weeks. Endothelial dysfunction, insulin resistance, and hepatic lipid contents were determined. Results. VitB6 administration remarkably increased acetylcholine-induced endothelium-dependent relaxation and decreased random blood glucose level in Apoe (-/-) mice fed with HFD. In addition, VitB6 improved the tolerance of glucose and insulin, normalized the histopathology of liver, and reduced hepatic lipid accumulation but did not affect the liver functions. Clinical and biochemical analysis indicated that the levels of VitB6 were decreased in patients with fatty liver. Conclusions. Vitamin B6 prevents endothelial dysfunction, insulin resistance, and hepatic lipid accumulation in Apoe (-/-) mice fed with HFD. Supplementation of VitB6 should be considered to prevent metabolic syndrome.
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Affiliation(s)
- Zhan Liu
- Department of Clinical Nutrition and Gastroenterology, The First Affiliated Hospital (People's Hospital of Hunan Province), Hunan Normal University, Changsha 430070, China
| | - Peng Li
- College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
| | - Zhi-Hong Zhao
- Department of Clinical Nutrition and Gastroenterology, The First Affiliated Hospital (People's Hospital of Hunan Province), Hunan Normal University, Changsha 430070, China
| | - Yu Zhang
- Department of Clinical Nutrition and Gastroenterology, The First Affiliated Hospital (People's Hospital of Hunan Province), Hunan Normal University, Changsha 430070, China
| | - Zhi-Min Ma
- Division of Endocrinology, The Second Affiliated Hospital, Soochow University, Suzhou 215000, China
| | - Shuang-Xi Wang
- College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital, School of Medicine, Shandong University, Jinan 250012, China
- *Shuang-Xi Wang:
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Zang S, Ma X, Zhuang Z, Liu J, Bian D, Xun Y, Zhang Q, Zhao F, Yang W, Liu J, Luo Y, Liu Y, Ye B, Ye D, Shi J. Increased ratio of neutrophil elastase toα1-antitrypsin is closely associated with liver inflammation in patients with nonalcoholic steatohepatitis. Clin Exp Pharmacol Physiol 2015; 43:13-21. [PMID: 26444279 DOI: 10.1111/1440-1681.12499] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 10/02/2015] [Indexed: 01/14/2023]
Affiliation(s)
- Shufei Zang
- Department of Endocrinology; Hangzhou Normal University Affiliated Hospital; Hangzhou Zhejiang China
- Second Clinical Medical College; Zhejiang Chinese Medical University; Hangzhou Zhejiang China
| | - Xiaojie Ma
- Second Clinical Medical College; Zhejiang Chinese Medical University; Hangzhou Zhejiang China
| | - Zhenjie Zhuang
- Centre for Translational Medicine; Hangzhou Normal University Affiliated Hospital; Hangzhou Zhejiang China
| | - Jing Liu
- Second Clinical Medical College; Zhejiang Chinese Medical University; Hangzhou Zhejiang China
| | - Dongxue Bian
- Second Clinical Medical College; Zhejiang Chinese Medical University; Hangzhou Zhejiang China
| | - Yunhao Xun
- Department of Liver Diseases; Xixi Hospital of Hangzhou; Hangzhou Zhejiang China
| | - Qiuling Zhang
- Department of Endocrinology; Hangzhou Normal University Affiliated Hospital; Hangzhou Zhejiang China
| | - Falin Zhao
- Department of Health Management; School of Medicine; Hangzhou Normal University; Hangzhou Zhejiang China
| | - Wenjun Yang
- Department of Pathology; Hangzhou Normal University Affiliated Hospital; Hangzhou Zhejiang China
| | - Juan Liu
- Department of Pathology; Hangzhou Normal University Affiliated Hospital; Hangzhou Zhejiang China
| | - Yan Luo
- Centre for Translational Medicine; Hangzhou Normal University Affiliated Hospital; Hangzhou Zhejiang China
| | - Yinlan Liu
- Centre for Translational Medicine; Hangzhou Normal University Affiliated Hospital; Hangzhou Zhejiang China
| | - Bei Ye
- Centre for Translational Medicine; Hangzhou Normal University Affiliated Hospital; Hangzhou Zhejiang China
| | - Dewei Ye
- Department of Medicine; Faculty of Medicine; The University of Hong Kong; Hong Kong China
| | - Junping Shi
- Centre for Translational Medicine; Hangzhou Normal University Affiliated Hospital; Hangzhou Zhejiang China
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244
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Xu C, Qiao Z, Lu Y, Zhang D, Jia Z, Zhuang X, Shi Y, Xu T, Xing L, Shen J. Influence of Fatty Liver on the Severity and Clinical Outcome in Acute Pancreatitis. PLoS One 2015; 10:e0142278. [PMID: 26571385 PMCID: PMC4646451 DOI: 10.1371/journal.pone.0142278] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 10/20/2015] [Indexed: 02/08/2023] Open
Abstract
Acute pancreatitis (AP) is a common disease in the department of gastroenterology with variable severity, from being mild and self-limited to severe and fatal. The early diagnosis and accurate prediction of AP severity are of great importance. Our primary observation showed that fatty liver (FL) was frequently detected in patients with AP. In this retrospective study, we aimed to evaluate the relation between FL and the severity and outcomes of AP. The medical records of 2671 patients with AP were reviewed retrospectively, and characteristics of AP patients were recorded. FL was assessed by abdominal CT scan, and AP patients were categorized by the occurrence of FL for the analysis. The variation of mortality, clinical severity and the appearance of CT were analyzed between the non-FL group and FL groups. Compared with patients without FL, an obviously higher rate of death and higher frequency of severe AP (SAP) and necrotizing AP (ANP) were observed in patients with FL, as well as the incidence of local complications and systemic complications. Taking obesity into consideration, a higher rate of death and more severe AP were found in patients with FL, no matter whether they were obese or not. Alcoholic fatty liver (AFL) and non-alcoholic fatty liver (NAFL) were also separated for comparison in this study; the incidence of ANP and the clinical severity had no significant difference between the AFL and NAFL groups. In conclusion, FL could influence the severity and clinical outcome and may play a prognostic role in AP. This study is of clinical significance, because few reports have been previously issued on FL and AP.
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Affiliation(s)
- Chunfang Xu
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Jiangsu, China
| | - Zhenguo Qiao
- Department of Gastroenterology, Affiliated Wujiang Hospital of Nantong University, Jiangsu, China
| | - Yongda Lu
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Jiangsu, China
| | - Deqing Zhang
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Jiangsu, China
| | - Zhenyu Jia
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Jiangsu, China
| | - Xiaohui Zhuang
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Jiangsu, China
| | - Yuqi Shi
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Jiangsu, China
| | - Ting Xu
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Jiangsu, China
| | - Lihua Xing
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Jiangsu, China
| | - Jiaqing Shen
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Jiangsu, China
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245
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Siddiqui RA, Xu Z, Harvey KA, Pavlina TM, Becker MJ, Zaloga GP. Comparative study of the modulation of fructose/sucrose-induced hepatic steatosis by mixed lipid formulations varying in unsaturated fatty acid content. Nutr Metab (Lond) 2015; 12:41. [PMID: 26583036 PMCID: PMC4650347 DOI: 10.1186/s12986-015-0038-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 11/08/2015] [Indexed: 12/18/2022] Open
Abstract
Background Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in developed countries. NAFLD encompasses a spectrum of diseases, ranging from hepatic steatosis to non-alcoholic steatohepatitis (NASH), cirrhosis, and liver failure. The etiology of NAFLD remains unclear but is thought to relate to increased fatty acid flux within the liver that results in toxic fatty acid metabolite production. One source of increased fatty acid flux is fructose/sucrose-induced hepatic lipogenesis. Current treatment for NAFLD encompasses dietary modifications. However, little scientific evidence exists on which to base many dietary recommendations, especially the intake of different types of carbohydrates and fats. We hypothesized that lipid mixtures of unsaturated fatty acids would inhibit lipogenesis and subsequent hepatic steatosis induced by high carbohydrate diets. The aim of this study was to examine the effects of different complex mixtures of fatty acids upon the development of fructose/sucrose-induced hepatic steatosis. Methods C57BL/6 mice were randomized to normocaloric chow-based diets that varied in the type of carbohydrate (starch, sucrose, fructose). Animals in each carbohydrate group were further randomized to diets that varied in lipid type (no additional lipid, soybean oil, fish oil, olive/soybean oil, macadamia nut oil). These oils were chosen based upon their content of omega-6 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, omega-9 monounsaturated fatty acids, or omega-7 monounsaturated fatty acids. Fatty acid flux in the liver was determine by assessing hepatic lipid content (steatosis). We also assessed fatty acid levels in the plasma and liver of the animals, hepatic lipogenesis activity, hepatic stearoyl-CoA-1 desaturase activity, and hepatic elongase activity. Results Animals consumed similar amounts of the diets and maintained normal body weights throughout the study. Both sucrose and fructose induced hepatic lipogenesis and steatosis, with fructose being more potent. All mixed lipids similarly inhibited steatosis, limiting lipid content to levels found in the control (starch) animals. Lipogenesis and stearoyl-CoA-1 desaturase activity were increased in the sucrose and fructose groups. Levels of these enzymatic processes remained at baseline in all of the lipid groups. Conclusion This is the first study to compare various complex lipid mixtures, based upon dietary oils with different types of long-chain fatty acids, upon development of sucrose/fructose-induced steatosis. Both carbohydrate source and lipid content appear important for the modulation of steatosis. Moderate intake of complex lipids with high unsaturated to saturated fatty acid ratios inhibited both lipogenesis and steatosis.
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Affiliation(s)
- Rafat A Siddiqui
- Methodist Research Institute, Indiana University Health, 1800 N. Capitol Ave, Indianapolis, IN 46202 USA
| | - Zhidong Xu
- Methodist Research Institute, Indiana University Health, 1800 N. Capitol Ave, Indianapolis, IN 46202 USA
| | - Kevin A Harvey
- Methodist Research Institute, Indiana University Health, 1800 N. Capitol Ave, Indianapolis, IN 46202 USA
| | | | | | - Gary P Zaloga
- Baxter Healthcare Corporation, Deerfield, IL 60015 USA
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246
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Geng T, Sutter A, Harland MD, Law BA, Ross JS, Lewin D, Palanisamy A, Russo SB, Chavin KD, Cowart LA. SphK1 mediates hepatic inflammation in a mouse model of NASH induced by high saturated fat feeding and initiates proinflammatory signaling in hepatocytes. J Lipid Res 2015; 56:2359-71. [PMID: 26482537 DOI: 10.1194/jlr.m063511] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Indexed: 11/20/2022] Open
Abstract
Steatohepatitis occurs in up to 20% of patients with fatty liver disease and leads to its primary disease outcomes, including fibrosis, cirrhosis, and increased risk of hepatocellular carcinoma. Mechanisms that mediate this inflammation are of major interest. We previously showed that overload of saturated fatty acids, such as that which occurs with metabolic syndrome, induced sphingosine kinase 1 (SphK1), an enzyme that generates sphingosine-1-phosphate (S1P). While data suggest beneficial roles for S1P in some contexts, we hypothesized that it may promote hepatic inflammation in the context of obesity. Consistent with this, we observed 2-fold elevation of this enzyme in livers from humans with nonalcoholic fatty liver disease and also in mice with high saturated fat feeding, which recapitulated the human disease. Mice exhibited activation of NFκB, elevated cytokine production, and immune cell infiltration. Importantly, SphK1-null mice were protected from these outcomes. Studies in cultured cells demonstrated saturated fatty acid induction of SphK1 message, protein, and activity, and also a requirement of the enzyme for NFκB signaling and increased mRNA encoding TNFα and MCP1. Moreover, saturated fat-induced NFκB signaling and elevation of TNFα and MCP1 mRNA in HepG2 cells was blocked by targeted knockdown of S1P receptor 1, supporting a role for this lipid signaling pathway in inflammation in nonalcoholic fatty liver disease.
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Affiliation(s)
- Tuoyu Geng
- Departments of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425
| | - Alton Sutter
- Surgery, Medical University of South Carolina, Charleston, SC 29425
| | - Michael D Harland
- Departments of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425
| | - Brittany A Law
- Departments of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425 Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29403
| | - Jessica S Ross
- Departments of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425
| | - David Lewin
- Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425
| | - Arun Palanisamy
- Surgery, Medical University of South Carolina, Charleston, SC 29425
| | - Sarah B Russo
- Departments of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425
| | - Kenneth D Chavin
- Surgery, Medical University of South Carolina, Charleston, SC 29425
| | - L Ashley Cowart
- Departments of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425 Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29403
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247
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Sepideh A, Karim P, Hossein A, Leila R, Hamdollah M, Mohammad E G, Mojtaba S, Mohammad S, Ghader G, Seyed Moayed A. Effects of Multistrain Probiotic Supplementation on Glycemic and Inflammatory Indices in Patients with Nonalcoholic Fatty Liver Disease: A Double-Blind Randomized Clinical Trial. J Am Coll Nutr 2015; 35:500-505. [PMID: 26430826 DOI: 10.1080/07315724.2015.1031355] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Nonalcoholic fatty liver disease (NAFLD) is a condition defined by exceeding triglycerides accumulation in the liver. The condition can develop into fibrosis, cirrhosis, and hepatocellular carcinoma. Considering the ever-increasing prevalence of NAFLD, the aim of the present study was to investigate the effects of probiotic supplementation on glycemic and inflammatory indices in patients with NAFLD. METHODS This randomized clinical trial was conducted on 42 patients with NAFLD who had been referred to a gastroenterology clinic. Subjects in the intervention and control groups consumed 2 capsules/day probiotic or placebo, respectively, for 8 weeks. Fasting blood sugar (FBS), insulin, insulin resistance, tumor necrosis factor alpha (TNF-α), and interleukin 6 (IL-6) were measured at baseline and at the end of the study. RESULTS Means of FBS, insulin, insulin resistance, and IL-6 were significantly different between groups after intervention (p < 0.05), whereas TNF-α was not significantly modified (p > 0.05). In the probiotic group, insulin, insulin resistance, TNF-α, and IL-6 decreased significantly at the end of the study compared to the beginning of study. CONCLUSION Considering the effects of probiotic supplementation on the reduction of glycemic and inflammatory indices in patients with NAFLD, consumption of probiotics is recommended as a complementary therapy in these patients.
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Affiliation(s)
| | - Parastouei Karim
- e Baqiyatallah University of Medical Sciences, Tehran, IRAN; Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences , Tehran , IRAN
| | | | | | | | | | - Sepandi Mojtaba
- c Department of Epidemiology and Biostatistics , Health School
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248
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Ahowesso C, Black PN, Saini N, Montefusco D, Chekal J, Malosh C, Lindsley CW, Stauffer SR, DiRusso CC. Chemical inhibition of fatty acid absorption and cellular uptake limits lipotoxic cell death. Biochem Pharmacol 2015; 98:167-81. [PMID: 26394026 DOI: 10.1016/j.bcp.2015.09.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 09/03/2015] [Indexed: 12/31/2022]
Abstract
Chronic elevation of plasma free fatty acid (FFA) levels is commonly associated with obesity, type 2 diabetes, cardiovascular disease and some cancers. Experimental evidence indicates FFA and their metabolites contribute to disease development through lipotoxicity. Previously, we identified a specific fatty acid transport inhibitor CB16.2, a.k.a. Lipofermata, using high throughput screening methods. In this study, efficacy of transport inhibition was measured in four cell lines that are models for myocytes (mmC2C12), pancreatic β-cells (rnINS-1E), intestinal epithelial cells (hsCaco-2), and hepatocytes (hsHepG2), as well as primary human adipocytes. The compound was effective in inhibiting uptake with IC50s between 3 and 6μM for all cell lines except human adipocytes (39μM). Inhibition was specific for long and very long chain fatty acids but had no effect on medium chain fatty acids (C6-C10), which are transported by passive diffusion. Derivatives of Lipofermata were evaluated to understand structural contributions to activity. Lipofermata prevented palmitate-mediated oxidative stress, induction of BiP and CHOP, and cell death in a dose-dependent manner in hsHepG2 and rnINS-1E cells, suggesting it will prevent induction of fatty acid-mediated cell death pathways and lipotoxic disease by channeling excess fatty acids to adipose tissue and away from liver and pancreas. Importantly, mice dosed orally with Lipofermata were not able to absorb (13)C-oleate demonstrating utility as an inhibitor of fatty acid absorption from the gut.
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Affiliation(s)
- Constance Ahowesso
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - Paul N Black
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - Nipun Saini
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - David Montefusco
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - Jessica Chekal
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States
| | - Chrysa Malosh
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, United States
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, United States; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, United States
| | - Shaun R Stauffer
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, United States; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, United States
| | - Concetta C DiRusso
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0664, United States.
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249
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Pathil A, Liebisch G, Okun JG, Chamulitrat W, Schmitz G, Stremmel W. Ursodeoxycholyl Lysophosphatidylethanolamide modifies aberrant lipid profiles in NAFLD. Eur J Clin Invest 2015; 45:925-31. [PMID: 26108973 DOI: 10.1111/eci.12486] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 06/20/2015] [Indexed: 12/26/2022]
Abstract
BACKGROUND Hepatic fat accumulation with disturbed lipid homoeostasis is a hallmark of nonalcoholic fatty liver disease (NAFLD). The bile acid phospholipid conjugate Ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE) is a novel anti-inflammatory agent with hepatoprotective effects in murine high-fat-diet (HFD)-induced NAFLD. The aim of this work was to study changes in the hepatic lipidome due to UDCA-LPE. MATERIALS AND METHODS High fat diet mouse model, mass spectometry, RT-PCR. RESULTS Hepatic lipid extracts of HFD mice were analysed by mass spectrometry. The results determined higher levels of total, saturated, mono- and diunsaturated fatty acids (FA) in HFD mice, which were decreased by UDCA-LPE predominantly by the reducing the most abundant FA species palmitic acid and oleic acid. Unlike other FA species, levels of long-chain polyunsaturated fatty acids (LCPUFA), which are composed of arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were increased in HFD mice upon UDCA-LPE treatment, mainly due to elevated hepatic ARA pools. Analysis of hepatic phospholipids species showed a decrease in total phosphatidylcholine (PC), especially monounsaturated PC (PUFA-PC) levels in HFD mice. Loss of total PC was reversed due to UDCA-LPE by increasing hepatic PUFA-PC pools. Gene expression analysis showed that UDCA-LPE upregulated PPARα, a key transcriptional regulator of fatty acid oxidation, as well as downstream target genes CPT1α and AOX, which are crucially involved in mitochondrial and peroxisomal fatty acid oxidation. CONCLUSION UDCA-LPE modulates defective fatty acid metabolism during experimental NAFLD thereby restoring altered lipid profiles in addition to its pronounced anti-inflammatory effects. Thus, UDCA-LPE may be a promising drug candidate for the management of NAFLD.
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Affiliation(s)
- Anita Pathil
- Department of Internal Medicine IV, Gastroenterology and Hepatology, University of Heidelberg, Heidelberg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Regensburg, Germany
| | - Jürgen G Okun
- Department of General Pediatrics, Division of Inborn Metabolic Diseases, University of Heidelberg, Heidelberg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, Gastroenterology and Hepatology, University of Heidelberg, Heidelberg, Germany
| | - Gerd Schmitz
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Regensburg, Germany
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, Gastroenterology and Hepatology, University of Heidelberg, Heidelberg, Germany
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250
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García-Cañaveras JC, Jiménez N, Gómez-Lechón MJ, Castell JV, Donato MT, Lahoz A. LC-MS untargeted metabolomic analysis of drug-induced hepatotoxicity in HepG2 cells. Electrophoresis 2015; 36:2294-2302. [PMID: 26031481 DOI: 10.1002/elps.201500095] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 05/06/2015] [Accepted: 05/07/2015] [Indexed: 12/15/2022]
Abstract
Hepatotoxicity is the number one cause for agencies not approving and withdrawing drugs for the market. Drug-induced human hepatotoxicity frequently goes undetected in preclinical safety evaluations using animal models. Human-derived in vitro models represent a common alternative to in vivo tests to detect toxic effects during preclinical testing. Most current in vitro toxicity assays rely on the measurement of nonspecific or low sensitive endpoints, which result in poor concordance with human liver toxicity. Therefore, making more accurate predictions of the potential hepatotoxicity of new drugs remains a challenge. Metabolomics, whose aim is to globally assess all the metabolites present in a biological sample, may represent an alternative in the search for sensitive sublethal markers of drug-induced hepatotoxicity. To this end, a comprehensive LC-MS-based untargeted metabolite profiling analysis of HepG2 cells, exposed to a set of well-described model hepatotoxins and innocuous compounds, was performed. It allowed to determine meaningful metabolic changes triggered by a toxic insult and gave a first estimation of the main toxicity-related pathways. Based on these metabolic patterns, a partial least squares-discriminant analysis model, able to discriminate between nontoxic and hepatotoxic compounds, was constructed. The approach described herein may provide an alternative for animal testing in preclinical stages of drug development and a controlled experimental approach to gain a better understanding of the underlying causes of hepatotoxicity.
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Affiliation(s)
- Juan Carlos García-Cañaveras
- Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria-Fundación Hospital La Fe, Valencia, Spain.,CIBERehd, Centro de Investigaciones Biomédicas en Red de Enfermedades Hepáticas y Digestivas, FIS, Spain.,Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Valencia, Spain
| | - Nuria Jiménez
- Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria-Fundación Hospital La Fe, Valencia, Spain.,CIBERehd, Centro de Investigaciones Biomédicas en Red de Enfermedades Hepáticas y Digestivas, FIS, Spain
| | - M José Gómez-Lechón
- Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria-Fundación Hospital La Fe, Valencia, Spain.,CIBERehd, Centro de Investigaciones Biomédicas en Red de Enfermedades Hepáticas y Digestivas, FIS, Spain
| | - José V Castell
- Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria-Fundación Hospital La Fe, Valencia, Spain.,CIBERehd, Centro de Investigaciones Biomédicas en Red de Enfermedades Hepáticas y Digestivas, FIS, Spain.,Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Valencia, Spain
| | - M Teresa Donato
- Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria-Fundación Hospital La Fe, Valencia, Spain.,CIBERehd, Centro de Investigaciones Biomédicas en Red de Enfermedades Hepáticas y Digestivas, FIS, Spain.,Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Valencia, Spain
| | - Agustín Lahoz
- Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria-Fundación Hospital La Fe, Valencia, Spain.,CIBERehd, Centro de Investigaciones Biomédicas en Red de Enfermedades Hepáticas y Digestivas, FIS, Spain.,Unidad Analítica Instituto de Investigación Sanitaria-Fundación Hospital La Fe, Valencia, Spain
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