1
|
Sanal MG. Is the change from NAFLD to MASLD driven by political correctness? J Hepatol 2024; 80:e74-e76. [PMID: 37683734 DOI: 10.1016/j.jhep.2023.08.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 08/17/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023]
|
2
|
Hamed M, Akhigbe R, Aremu A, Odetayo A. Zinc normalizes hepatic lipid handling via modulation of ADA/XO/UA pathway and caspase 3 signaling in highly active antiretroviral therapy-treated Wistar rats. Chem Biol Interact 2022; 368:110233. [DOI: 10.1016/j.cbi.2022.110233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/17/2022] [Accepted: 10/21/2022] [Indexed: 11/23/2022]
|
3
|
Bertran L, Eigbefoh-addeh A, Portillo-carrasquer M, Barrientos-riosalido A, Binetti J, Aguilar C, Ugarte Chicote J, Bartra H, Artigas L, Coma M, Richart C, Auguet T. Identification of the Potential Molecular Mechanisms Linking RUNX1 Activity with Nonalcoholic Fatty Liver Disease, by Means of Systems Biology. Biomedicines 2022; 10:1315. [PMID: 35740337 PMCID: PMC9219880 DOI: 10.3390/biomedicines10061315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/24/2022] [Accepted: 06/01/2022] [Indexed: 12/10/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic hepatic disease; nevertheless, no definitive diagnostic method exists yet, apart from invasive liver biopsy, and nor is there a specific approved treatment. Runt-related transcription factor 1 (RUNX1) plays a major role in angiogenesis and inflammation; however, its link with NAFLD is unclear as controversial results have been reported. Thus, the objective of this work was to determine the proteins involved in the molecular mechanisms between RUNX1 and NAFLD, by means of systems biology. First, a mathematical model that simulates NAFLD pathophysiology was generated by analyzing Anaxomics databases and reviewing available scientific literature. Artificial neural networks established NAFLD pathophysiological processes functionally related to RUNX1: hepatic insulin resistance, lipotoxicity, and hepatic injury-liver fibrosis. Our study indicated that RUNX1 might have a high relationship with hepatic injury-liver fibrosis, and a medium relationship with lipotoxicity and insulin resistance motives. Additionally, we found five RUNX1-regulated proteins with a direct involvement in NAFLD motives, which were NFκB1, NFκB2, TNF, ADIPOQ, and IL-6. In conclusion, we suggested a relationship between RUNX1 and NAFLD since RUNX1 seems to regulate NAFLD molecular pathways, posing it as a potential therapeutic target of NAFLD, although more studies in this field are needed.
Collapse
|
4
|
Abstract
Liver cirrhosis is the final stage of continuous hepatic inflammatory activity derived by viral, metabolic or autoimmune origin. In the last years, cirrhosis was considered a unique and static condition; recently was accepted some patients subgroups with different liver injury degrees that coexist under the same diagnosis, with implications about the natural disease history. The liver growth factor (LGF) is a potent in vivo and in vitro mitogenic agent and an inducer of hepatic regeneration (HR) through the hepatocytes DNA synthesis. The clinical implications of the LGF levels in cirrhosis, are not clear and even with having a fundamental role in the liver regeneration processes, the studies suggest that it could be a cirrhosis severity marker, in acute liver failure and in chronic hepatitis. Its role as predictor of mortality in fulminant hepatic insufficiency patients has been suggested. HR is one of the most enigmatic and fascinating biological phenomena. The rapid volume and liver function restoration after a major hepatectomy (>70%) or severe hepatocellular damage and its strict regulation of tissue damage response after the cessation, is an exclusive property of the liver. HR is the clinical applications fundament, such as extensive hepatic resections (>70% of the liver parenchyma), segmental transplantation or living donor transplantation, sequential hepatectomies, isolated portal embolization or associated with in situ hepatic transection, temporary artificial support in acute liver failure and the possible cell therapy clinical applications.
Collapse
Affiliation(s)
- Esmeralda Zuñiga-Aguilar
- Universidad Autonoma de Ciudad Juárez, Depto de Ingeniería Eléctrica y Computación, Ciudad Juárez, Chih., México
| | - Odin Ramírez-Fernández
- Tecnologico Nacional de Mexico, Depto. De Ciencias Basicas, Tlalnepantla de Baz, Mexico
- Facultad de Medicina, HIPAM, Universidad Nacional Autonoma de Mexico, Ciudad de México, Mexico
| |
Collapse
|
5
|
Omolekulo TE, Michael OS, Olatunji LA. Dipeptidyl peptidase-4 inhibition protects the liver of insulin-resistant female rats against triglyceride accumulation by suppressing uric acid. Biomed Pharmacother 2019; 110:869-77. [PMID: 30557836 DOI: 10.1016/j.biopha.2018.12.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/20/2018] [Accepted: 12/07/2018] [Indexed: 02/07/2023] Open
Abstract
Dipeptidyl peptidase-4 (DPP-4) inhibition has been shown to exert beneficial effects against insulin resistance (IR) and type 2 diabetes. Combined oral contraceptive (COC) treatment is associated with impaired glucose and lipid metabolism but the mechanisms are elusive. We therefore, hypothesized that DPP-4 inhibition ameliorates COC-induced glucose dysregulation and hepatic triglyceride (TG) accumulation through adenosine deaminase (ADA) /xanthine oxidase (XO) /uric acid-dependent pathway. Female Wistar rats received (po) vehicle and COC (1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel; po) with or without DPP-4 inhibitor (sitagliptin; 100 mg/kg; po) for 8 weeks (n = 6/group). Glucose dysmetabolism was assessed by elevated fasting blood glucose, impaired oral glucose tolerance test and homeostatic model assessment of IR. Treatment with COC led to increased plasma fasting glucose, triglyceride-glucose index, 1-h postload glucose response, insulin, free fatty acid, IR and impaired glucose tolerance. COC treatment also resulted in increased plasma and hepatic TG, TG/HDL-cholesterol ratio, malondialdehyde, uric acid (plasma; 25.2 ± 0.6 mg/dl; hepatic 128.9 ± 8.0 mg/100 mg tissue), lactate dehydrogenase, DPP-4, ADA and XO (plasma;10.5 ± 1.1 U/L; hepatic 21.2 ± 1.4 U/g protein) activities. Likewise, COC led to reduction in nitric oxide level. However, DPP-4 inhibition significantly ameliorated these alterations induced by COC treatment through suppression of uric acid (plasma; 15.1 ± 1.0 mg/dl, hepatic; 75.6 ± 5.0 mg/100 mg tissue), XO (plasma; 4.1 ± 0.9 U/L, hepatic; 8.7 ± 0.4 U/g protein), ADA and DPP-4 activities suggesting their involvement in glucose dysregulation and hepatic TG accumulation induced by COC treatment. Therefore, DPP-4 inhibition would impact positively on cardiometabolic disorders, at least in part, through XO, ADA and uric acid suppression.
Collapse
|
6
|
Omolekulo TE, Areola ED, Badmus OO, Michael OS, Kim I, Olatunji LA. Inhibition of adenosine deaminase and xanthine oxidase by valproic acid abates hepatic triglyceride accumulation independent of corticosteroids in female rats treated with estrogen-progestin. Can J Physiol Pharmacol 2018; 96:1092-1103. [PMID: 30001502 DOI: 10.1139/cjpp-2018-0231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Elevated circulating uric acid has been postulated to play an important pathophysiological role in estrogen-progestin combined oral contraceptive (COC)-induced hypertension and endothelial dysfunction. We hypothesized that disruption of glucoregulation and liver triglyceride (TG) accumulation induced by COC use would be abated by valproic acid (VPA) treatment through suppression of adenosine deaminase (ADA) and xanthine oxidase (XO) activities. Female Wistar rats aged 9-10 weeks were treated with a combination of estrogen-progestin COC steroids (1.0 μg ethinylestradiol and 5.0 μg levonorgestrel; p.o.) with or without VPA (100.0 mg/kg; p.o.) daily for 6 weeks. The result shows that the disrupted glucoregulation and associated elevated hepatic ADA activity, plasma and hepatic XO activity, uric acid (UA), TG/HDL-cholesterol, total cholesterol, and malondialdehyde induced by COC treatment were attenuated by VPA treatment. However, VPA did not have any effect on plasma aldosterone, corticosterone, ADA, circulating and hepatic free fatty acid. Our results demonstrate that suppression of plasma and hepatic XO activities, along with hepatic ADA activity and UA by VPA treatment, protects against disrupted glucoregulation and increased liver TG by COC independent of elevated corticosteroids. The findings imply that VPA would provide protection against the development of cardiometabolic disorder via inhibition of the ADA/XO/UA-mediated pathway.
Collapse
Affiliation(s)
- Tolulope Eniola Omolekulo
- a HOPE Cardiometabolic Research Team, Department of Physiology, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Emmanuel Damilare Areola
- a HOPE Cardiometabolic Research Team, Department of Physiology, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Olufunto Olayinka Badmus
- a HOPE Cardiometabolic Research Team, Department of Physiology, College of Health Sciences, University of Ilorin, Ilorin, Nigeria.,b Department of Public Health, Kwara State University, Malete, Nigeria
| | - Olugbenga Samuel Michael
- a HOPE Cardiometabolic Research Team, Department of Physiology, College of Health Sciences, University of Ilorin, Ilorin, Nigeria.,c Cardiometabolic Research Unit, Department of Physiology, College of Health Sciences, Bowen University, Iwo, Nigeria
| | - Inkyeom Kim
- d Cardiovascular Research Institute and Department of Pharmacology, Kyungpook National University School of Medicine, Daegu, Republic of Korea
| | - Lawrence Aderemi Olatunji
- a HOPE Cardiometabolic Research Team, Department of Physiology, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| |
Collapse
|
7
|
Ramanathan R, Sivanesan K. Evaluation of ameliorative ability of Silibinin against zidovudine and isoniazid-induced hepatotoxicity and hyperlipidaemia in rats: Role of Silibinin in Phase I and II drug metabolism. Chem Biol Interact 2017; 273:142-53. [PMID: 28619387 DOI: 10.1016/j.cbi.2017.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 06/05/2017] [Accepted: 06/08/2017] [Indexed: 10/19/2022]
Abstract
HIV/AIDS patients have suppressed immune system, making them vulnerable to many opportunistic infections including tuberculosis (TB). The patients who are co-infected with TB undergo combined regimens with anti-retroviral drugs such as zidovudine (AZT) and anti-tubercular drug such as isoniazid (INH) for therapy leading to hepatotoxicty. Silibinin (SBN), extracted from Silybum marianum commonly called as "Milk thistle" is used against several drugs-induced hepatotoxicity. The present study evaluates the ameliorative effect of SBN against AZT alone, INH alone, and INH + AZT-induced toxic insults to liver of rats. Wistar albino rats (n = 6/groups) were given INH and AZT (25 and 50 mg mg/kg b.w.) respectively either alone or in combination for a sub-chronic period of 45 days orally. Another group of rats received SBN (100 mg/kg b.w.) along with INH and AZT. The group that received propylene glycol served as control. AZT alone, INH alone and INH + AZT treatments showed parenchymal cell injury and cholestasis by highly significant increase in the activities of marker enzymes (aspartate and alanine transaminase, alkaline phosphatase, argino succinic acid lyase), bilirubin and protein. The presence of hyperlipidaemia was observed by analyzing lipid profiles in serum/liver/adipose tissue, gene expression (RT-PCR) of Phase-I and II metabolizing enzymes and western blot. Transmission electron microscopy study also revealed large vacuoles with membraneous debri, pleomorphic mitochondria, disruption of endoplasmic reticulum, presence of lipid droplets, breakage in cellular and nuclear membrane. SBN simultaneous treatment showed ameliorative effect against INH + AZT-induced hepatotoxicity and hyperlipidemia in rats.
Collapse
|
8
|
Belemets N, Kobyliak N, Virchenko O, Falalyeyeva T, Olena T, Bodnar P, Savchuk O, Galenova T, Caprnda M, Rodrigo L, Skladany L, Delev D, Opatrilova R, Kruzliak P, Beregova T, Ostapchenko L. Effects of polyphenol compounds melanin on NAFLD/NASH prevention. Biomed Pharmacother 2017; 88:267-276. [DOI: 10.1016/j.biopha.2017.01.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/25/2016] [Accepted: 01/04/2017] [Indexed: 12/17/2022] Open
|
9
|
Papageorgiou MV, Hadziyannis E, Tiniakos D, Georgiou A, Margariti A, Kostas A, Papatheodoridis GV. Serum levels of vascular endothelial growth factor in non-alcoholic fatty liver disease. Ann Gastroenterol 2016; 30:209-216. [PMID: 28243042 PMCID: PMC5320034 DOI: 10.20524/aog.2016.0107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 10/25/2016] [Indexed: 02/06/2023] Open
Abstract
Background This study aimed to assess the significance of serum levels of vascular endothelial growth factor (VEGF) in non-alcoholic fatty liver disease (NAFLD). Methods Sixty-seven consecutive NAFLD patients and 47 healthy controls who visited our liver clinics between May 2008 and December 2010 were included. The NAFLD diagnosis required elevated alanine aminotransferase and/or gamma-glutamyl transpeptidase levels, evidence of hepatic steatosis on ultrasound and/or liver histology, and exclusion of other causes of liver injury. Serum VEGF levels were determined by an enzyme immunoassay. Liver biopsy was obtained in 34 NAFLD patients. Histological lesions were scored by a liver histopathologist. Results Serum VEGF levels tended to be lower in matched NAFLD patients than in healthy controls (296±146 vs. 365±186 pg/mL, P=0.092); levels in patients with non-alcoholic steatohepatitis (NASH) also tended to be lower than in those with simple fatty liver (FL) (279±149 vs. 359±190 pg/mL, P=0.095); while VEGF levels were significantly lower in NASH patients than in healthy controls (279±149 vs. 365±186 pg/mL, P=0.041). VEGF levels offered poor predictability for the differentiation between NAFLD patients and controls or between NASH and FL patients. However, patients with high VEGF levels (≥300 pg/mL) were significantly more likely to have FL, either in the total NAFLD population (67% vs. 35%, P=0.019) or in the 34 NAFLD patients with liver biopsy (57% vs. 15%, P=0.023), while those with high VEGF levels also had a significantly lower mean fibrosis score (0.7±0.9 vs. 1.6±1.0, P=0.017). Conclusion Our data suggest that serum VEGF levels are equally high in healthy controls and in patients with simple fatty liver, but tend to decrease when NASH develops.
Collapse
Affiliation(s)
- Maria-Vasiliki Papageorgiou
- Academic Department of Gastroenterology, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital (Maria-Vasiliki Papageorgiou, Anastasia Georgiou, Athanasios Kostas, George V. Papatheodoridis)
| | - Emilia Hadziyannis
- 2nd Academic Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Hippokration General Hospital (Emilia Hadziyannis, Aikaterini Margariti)
| | - Dina Tiniakos
- Laboratory of Histology & Embryology, Medical School, National and Kapodistrian University of Athens (Dina Tiniakos), Athens, Greece
| | - Anastasia Georgiou
- Academic Department of Gastroenterology, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital (Maria-Vasiliki Papageorgiou, Anastasia Georgiou, Athanasios Kostas, George V. Papatheodoridis)
| | - Aikaterini Margariti
- 2nd Academic Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Hippokration General Hospital (Emilia Hadziyannis, Aikaterini Margariti)
| | - Athanasios Kostas
- Academic Department of Gastroenterology, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital (Maria-Vasiliki Papageorgiou, Anastasia Georgiou, Athanasios Kostas, George V. Papatheodoridis)
| | - George V Papatheodoridis
- Academic Department of Gastroenterology, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital (Maria-Vasiliki Papageorgiou, Anastasia Georgiou, Athanasios Kostas, George V. Papatheodoridis)
| |
Collapse
|
10
|
Ascha MS, Ascha ML, Hanouneh IA. Management of immunosuppressant agents following liver transplantation: Less is more. World J Hepatol 2016; 8:148-161. [PMID: 26839639 PMCID: PMC4724578 DOI: 10.4254/wjh.v8.i3.148] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 09/12/2015] [Accepted: 01/07/2016] [Indexed: 02/06/2023] Open
Abstract
Immunosuppression in organ transplantation was revolutionary for its time, but technological and population changes cast new light on its use. First, metabolic syndrome (MS) is increasing as a public health issue, concomitantly increasing as an issue for post-orthotopic liver transplantation patients; yet the medications regularly used for immunosuppression contribute to dysfunctional metabolism. Current mainstay immunosuppression involves the use of calcineurin inhibitors; these are potent, but nonspecifically disrupt intracellular signaling in such a way as to exacerbate the impact of MS on the liver. Second, the impacts of acute cellular rejection and malignancy are reviewed in terms of their severity and possible interactions with immunosuppressive medications. Finally, immunosuppressive agents must be considered in terms of new developments in hepatitis C virus treatment, which undercut what used to be inevitable viral recurrence. Overall, while traditional immunosuppressive agents remain the most used, the specific side-effect profiles of all immunosuppressants must be weighed in light of the individual patient.
Collapse
|
11
|
Qasem RJ, Li J, Tang HM, Browne V, Mendez-Garcia C, Yablonski E, Pontiggia L, D'Mello AP. Decreased liver triglyceride content in adult rats exposed to protein restriction during gestation and lactation: role of hepatic triglyceride utilization. Clin Exp Pharmacol Physiol 2015; 42:380-8. [PMID: 25641378 DOI: 10.1111/1440-1681.12359] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 12/19/2014] [Accepted: 01/01/2015] [Indexed: 12/19/2022]
Abstract
We have previously demonstrated that protein restriction throughout gestation and lactation reduces liver triglyceride content in adult rat offspring. However, the mechanisms mediating the decrease in liver triglyceride content are not understood. The aim of the current study was to use a new group of pregnant animals and their offspring and determine the contribution of increased triglyceride utilization via the hepatic fatty-acid oxidation and triglyceride secretory pathways to the reduction in liver triglyceride content. Pregnant Sprague-Dawley rats received either a control or a low protein diet throughout pregnancy and lactation. Pups were weaned onto laboratory chow on day 28 and killed on day 65. Liver triglyceride content was reduced in male, but not female, low-protein offspring, both in the fed and fasted states. The reduction was accompanied by a trend towards higher liver carnitine palmitoyltransferase-1a activity, suggesting increased fatty-acid transport into the mitochondrial matrix. However, medium-chain acyl coenzyme A dehydrogenase activity within the mitochondrial matrix, expression of nuclear peroxisome proliferator activated receptor-α, and plasma levels of β-hydroxybutyrate were similar between low protein and control offspring, indicating a lack of change in fatty-acid oxidation. Hepatic triglyceride secretion, assessed by blocking peripheral triglyceride utilization and measuring serum triglyceride accumulation rate, and the activity of microsomal transfer protein, were similar between low protein and control offspring. Because enhanced triglyceride utilization is not a significant contributor, the decrease in liver triglyceride content in male low-protein offspring is likely due to alterations in liver fatty-acid transport or triglyceride biosynthesis.
Collapse
Affiliation(s)
- Rani J Qasem
- Department of Pharmaceutical Sciences, University of the Sciences in Philadelphia, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
In insulin-resistant states (obesity, pre-diabetes, and type 2 diabetes), hepatic production of glucose and lipid synthesis are heightened in concert, implying that insulin deficiency and insulin excess coexists in this setting. The fact that insulin may be inadequate or excessive at any one point in differing organs and tissues has many biologic ramifications. In this context the concept of metabolic compartmentalization in the liver is offered herein as one perspective of this paradox. In particular, we focus on the hypothesis that insulin resistance accentuates differences in periportal and perivenous hepatocytes, namely periportal glucose production and perivenous lipid synthesis. Subsequently, excessive production of glucose and accumulation of lipids could be expected in the livers of patients with obesity and insulin resistance. Overall, in this review, we provide our integrative perspective regarding how excessive production of glucose in periportal hepatocytes and accumulation of lipids in perivenous hepatocytes interact in insulin resistant states.
Collapse
Affiliation(s)
- Roberto B Bazotte
- a Department of Pharmacology and Therapeutics ; State University of Maringá ; Maringá , Paraná , PR Brazil
| | | | | |
Collapse
|
13
|
Abstract
Recent data indicate that hepatic angiogenesis, regardless of the etiology, takes place in chronic liver diseases (CLDs) that are characterized by inflammation and progressive fibrosis. Because anti-angiogenic therapy has been found to be efficient in the prevention of fibrosis in experimental models of CLDs, it is suggested that blocking angiogenesis could be a promising therapeutic option in patients with advanced fibrosis. Consequently, efforts are being directed to revealing the mechanisms involved in angiogenesis during the progression of liver fibrosis. Literature evidences indicate that hepatic angiogenesis and fibrosis are closely related in both clinical and experimental conditions. Hypoxia is a major inducer of angiogenesis together with inflammation and hepatic stellate cells. These profibrogenic cells stand at the intersection between inflammation, angiogenesis and fibrosis and play also a pivotal role in angiogenesis. This review mainly focuses to give a clear view on the relevant features that communicate angiogenesis with progression of fibrosis in CLDs towards the-end point of cirrhosis that may be translated into future therapies. The pathogenesis of hepatic angiogenesis associated with portal hypertension, viral hepatitis, non-alcoholic fatty liver disease and alcoholic liver disease are also discussed to emphasize the various mechanisms involved in angiogenesis during liver fibrogenesis.
Collapse
|
14
|
Abstract
Fatty liver is present in over ten percentage of the world population and it is a growing public health problem. Nonalcoholic fatty liver disease (NAFLD) is not a single disease, but encompasses a spectrum of diseases of different etiologies. It is difficult to find highly specific and sensitive diagnostic biomarkers when a disease is very complex. Therefore, we should aim to find relevant prognostic markers rather than accurate diagnostic markers which will help to minimize the frequency of liver biopsies to evaluate disease progression. There are several biomarker panels commercially available, however, there is no clear evidence that more sophisticated panels are better compared to simple criteria such as, presence of diabetes over five years, metabolic syndrome, obesity, obstructive sleep apnea, aspartate transaminase/alanine transaminase (ALT) ratio > 0.8 or ferritin levels > 1.5 times normal in patients with over six month history of raised ALT and/or ultrasonological evidence of fat in the liver. Currently the biomarker panels are not a replacement for a liver biopsy. However the need and benefit of liver biopsy in NAFLD is questionable because there is no convincing evidence that biopsy and detailed staging of NAFLD improves the management of NAFLD and benefits the patient. After all there is no evidence based treatment for NAFLD other than management of lifestyle and components of “metabolic syndrome”.
Collapse
|
15
|
Shi D, Zhan X, Yu X, Jia M, Zhang Y, Yao J, Hu X, Bao Z. Inhibiting CB1 receptors improves lipogenesis in an in vitro non-alcoholic fatty liver disease model. Lipids Health Dis 2014; 13:173. [PMID: 25406988 PMCID: PMC4247673 DOI: 10.1186/1476-511x-13-173] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 10/28/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The endocannabinoids system (ECs) mediated mainly by CB1 and CB2 receptors plays an important role in non-alcoholic fatty liver disease by regulating lipid metabolism. This study is to further investigate the expression of CB1 and CB2 in the fat accumulation liver cells and to identify possible underlying mechanism by detecting the key lipogenesis factors. METHODS Sodium oleate and sodium palmitate were added into the HepG2 cell line for forming fat accumulation liver cell. MTT assay was used to test the cell's cytotoxicity. The accumulation rate of fat in HepG2 cell was analyzed by the fluorescent staining. The mRNA and protein expression levels of CB1, CB2, SREBP-1c, ChREBP, L-PK, ACC1, FAS, LXRs and RXR were detected by RT-PCR and Western blot before and after the use of the antagonist. RESULTS The receptors of CB1 were expressed in HepG2 cells with low levels while in HepG2 fatty liver cells with higher levels (p < 0.05). However, after the application of antagonist, the expressions were significantly decreased (p < 0.05). The expressions of SREBP-1c, ChREBP and LXRs were detectable in HepG2 cells and the expressions were increased in HepG2 fatty liver cells (p < 0.05). After using the antagonists, the expressions of SREBP-1c, ChREBP, LXRs, ACC1 and FAS were significantly decreased (p < 0.05). But L-PK and RXR changed little in two groups (p > 0.05). CONCLUSION Results of the present study demonstrated that CB1 receptors had important pathophysiological effects on the formation of fatty liver. CB1 receptors could be regulated by SREBP-1c, ChREBP and LXRs. Therefore, targeting CB1 receptors for the treatment of NAFLD might have a potential application value.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Zhijun Bao
- Department of Gastroenterology, Huadong Hospital, Medical School of Shanghai Fudan University, Shanghai 200040, China.
| |
Collapse
|
16
|
Jung UJ, Choi MS. Obesity and its metabolic complications: the role of adipokines and the relationship between obesity, inflammation, insulin resistance, dyslipidemia and nonalcoholic fatty liver disease. Int J Mol Sci 2014; 15:6184-223. [PMID: 24733068 PMCID: PMC4013623 DOI: 10.3390/ijms15046184] [Citation(s) in RCA: 1160] [Impact Index Per Article: 116.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/27/2014] [Accepted: 04/01/2014] [Indexed: 02/06/2023] Open
Abstract
Accumulating evidence indicates that obesity is closely associated with an increased risk of metabolic diseases such as insulin resistance, type 2 diabetes, dyslipidemia and nonalcoholic fatty liver disease. Obesity results from an imbalance between food intake and energy expenditure, which leads to an excessive accumulation of adipose tissue. Adipose tissue is now recognized not only as a main site of storage of excess energy derived from food intake but also as an endocrine organ. The expansion of adipose tissue produces a number of bioactive substances, known as adipocytokines or adipokines, which trigger chronic low-grade inflammation and interact with a range of processes in many different organs. Although the precise mechanisms are still unclear, dysregulated production or secretion of these adipokines caused by excess adipose tissue and adipose tissue dysfunction can contribute to the development of obesity-related metabolic diseases. In this review, we focus on the role of several adipokines associated with obesity and the potential impact on obesity-related metabolic diseases. Multiple lines evidence provides valuable insights into the roles of adipokines in the development of obesity and its metabolic complications. Further research is still required to fully understand the mechanisms underlying the metabolic actions of a few newly identified adipokines.
Collapse
Affiliation(s)
- Un Ju Jung
- Center for Food and Nutritional Genomics Research, Kyungpook National University, 1370 Sankyuk Dong Puk-ku, Daegu 702-701, Korea.
| | - Myung-Sook Choi
- Center for Food and Nutritional Genomics Research, Kyungpook National University, 1370 Sankyuk Dong Puk-ku, Daegu 702-701, Korea.
| |
Collapse
|
17
|
Kuhla A, Hahn S, Butschkau A, Lange S, Wree A, Vollmar B. Lifelong Caloric Restriction Reprograms Hepatic Fat Metabolism in Mice. J Gerontol A Biol Sci Med Sci 2013; 69:915-22. [DOI: 10.1093/gerona/glt160] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
|
18
|
Miyoshi M, Ogawa A, Higurashi S, Kadooka Y. Anti-obesity effect of Lactobacillus gasseri SBT2055 accompanied by inhibition of pro-inflammatory gene expression in the visceral adipose tissue in diet-induced obese mice. Eur J Nutr 2013; 53:599-606. [PMID: 23917447 DOI: 10.1007/s00394-013-0568-9] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 07/23/2013] [Indexed: 12/17/2022]
Abstract
PURPOSE Probiotic Lactobacillus gasseri SBT2055 (LG2055) has an anti-obesity effect although it is unknown whether the effect influences inflammatory responses in adipose tissue and lipid metabolism in the liver, which are considered substantially relevant to adiposity. METHODS C57BL/6 mice were fed a 10%-fat diet containing LG2055 cells for 24 weeks. We then studied body weight, fat tissue mass, liver fat content and inflammatory genes in the adipose tissue, and lipogenic and lipolytic genes in the liver. RESULTS Consumption of LG2055 resulted in a significant reduction in body weight and fat tissue mass (epididymal and perirenal/retroperitoneal), with a lowered level of triglyceride content in the liver. DNA microarray analysis showed that LG2055 generally inhibited the up-regulation of pro-inflammatory genes, including CCL2 and CCR2, in the epididymal adipose tissue. In the liver, LG2055 tended to inhibit lipogenic gene up-regulation, including ACC1, FAS and SREBP1, but LG2055 did not markedly alter lipolytic genes. Real-time PCR analysis confirmed the DNA microarray results in part, showing a significant reduction in the mRNA expression of CCL2 in the epididymal adipose tissue, and a downward tendency in FAS mRNA expression in the liver, in the LG2055-fed group. CONCLUSIONS LG2055 significantly prevented body weight gain, fat accumulation and pro-inflammatory gene expression in the adipose tissue. Relatively lower triglyceride levels and reduced expression of lipogenic genes were also observed in the liver. It is suggested that improvement in the inflammatory state of the adipose tissue might be a possible mechanism underlying the anti-obesity effect of LG2055.
Collapse
Affiliation(s)
- Masaya Miyoshi
- Milk Science Research Institute, Megmilk Snow Brand Co. Ltd., 1-1-2 Minamidai, Kawagoe, Saitama, Japan,
| | | | | | | |
Collapse
|
19
|
Abstract
Fatty liver disease is epidemiologically associated with type 2 diabetes (T2D), leading to a speculation of a reciprocal cause-effect relationship and a vicious cycle of pathology. Here, we summarize recent literature reporting dissociation of hepatosteatosis from insulin resistance in genetic mouse models and clinical studies. We highlight rhythmic flows of metabolic intermediates between hepatic lipid synthesis and glucose production in normal circadian physiology. Blocking triglyceride (TG) secretion, subcellular lipid sequestration, lipolysis deficiency, enhanced lipogenesis, gluconeogenesis defects, or inhibition of fatty acid oxidation all result in hepatosteatosis without causing hyperglycemia or insulin resistance, suggesting that the cause-effect relationship between hepatosteatosis and diabetes does not exist in all situations.
Collapse
Affiliation(s)
- Zheng Sun
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Mitchell A. Lazar
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| |
Collapse
|
20
|
Lagomarsino A. Liver regeneration in nonalcoholic fatty liver disease. Medwave 2012. [DOI: 10.5867/medwave.2012.11.5559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
21
|
Abstract
It has become increasingly clear that angiogenesis occurring during chronic wound healing and fibrogenesis provides a key contribution to disease progression and complications. The association of fibrogenesis and angiogenesis should be regarded as crucial in the modern evaluation of liver disease progression and in the search for therapeutic targets. Physiological hepatic angiogenesis occurs during liver regeneration, contributing to the formation of new functional sinusoids. Pathological angiogenesis in liver is characterized by intrahepatic vascular remodeling with capillarization of the sinusoids and development of intrahepatic shunts, which lead to increased hepatic resistance and decreased effective hepatocyte perfusion. The problem of angiogenesis in chronic hepatitis C and nonalcoholic fatty liver disease has not been fully resolved. This manuscript briefly describes pathogenesis of new blood vessel formation in chronic hepatitis and potential role of angiogenesis in disease progression.
Collapse
|
22
|
Samanez CH, Caron S, Briand O, Dehondt H, Duplan I, Kuipers F, Hennuyer N, Clavey V, Staels B. The human hepatocyte cell lines IHH and HepaRG: models to study glucose, lipid and lipoprotein metabolism. Arch Physiol Biochem 2012; 118:102-11. [PMID: 22594799 DOI: 10.3109/13813455.2012.683442] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Metabolic diseases reach epidemic proportions. A better knowledge of the associated alterations in the metabolic pathways in the liver is necessary. These studies need in vitro human cell models. Several human hepatoma models are used, but the response of many metabolic pathways to physiological stimuli is often lost. Here, we characterize two human hepatocyte cell lines, IHH and HepaRG, by analysing the expression and regulation of genes involved in glucose and lipid metabolism. Our results show that the glycolysis pathway is activated by glucose and insulin in both lines. Gluconeogenesis gene expression is induced by forskolin in IHH cells and inhibited by insulin in both cell lines. The lipogenic pathway is regulated by insulin in IHH cells. Finally, both cell lines secrete apolipoprotein B-containing lipoproteins, an effect promoted by increasing glucose concentrations. These two human cell lines are thus interesting models to study the regulation of glucose and lipid metabolism.
Collapse
|
23
|
Janakiram NB, Mohammed A, Qian L, Choi CI, Steele VE, Rao CV. Chemopreventive effects of RXR-selective rexinoid bexarotene on intestinal neoplasia of Apc(Min/+) mice. Neoplasia 2012; 14:159-68. [PMID: 22431924 DOI: 10.1593/neo.111440] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 01/30/2012] [Accepted: 02/03/2012] [Indexed: 12/18/2022] Open
Abstract
Retinoid X receptor (RXR) has been implicated in several neoplastic diseases. Previously, we have shown that RXR-α is downregulated in human and rodent colonic tumors, suggesting a potential target for colon cancer prevention (http://www.cancer.org/Cancer/ColonandRectumCancer/DetailedGuide/colorectal-cancer-key-statistics). Experiments were designed to assess the chemopreventive efficacy of the selective RXR agonist bexarotene for the suppression of intestinal tumorigenesis in Apc(Min/+) mice. Before the efficacy studies, we determined that the maximal tolerated dose in C57BL/6J mice was less than 400 ppm. For the efficacy study, 6-week-old male and female C57BL/6J-Apc(Min/+) mice (nine mice per group) were fed diets containing 0, 30, and 60 ppm of bexarotene or 200 ppm of bexarotene for 80 days before intestinal tumors were evaluated. Dietary administration of 30 and 60 ppm of bexarotene suppressed the intestinal polyp formation by 38% (P < .015) and 60% (P < .0001) in males, respectively, and by 8.5% and 37% (P < .007) in females, respectively. Also, significant inhibition (50%-100%) of colonic tumor formation was observed in both male and female mice with bexarotene treatment. Administration of 200 ppm of bexarotene showed significant suppression of tumor formation (66%, P < .0001); however, it had significant toxicity. Intestinal tumors of bexarotene-fed mice showed significantly reduced expression of proliferating cell nuclear antigen (60%, P < .0001), cyclin D1, and cyclooxygenase 2 and increased RXR-α messenger RNA and uptake of oleate (34%, P < .01). Also, bexarotene-fed mice showed dose-dependent suppression of serum triglycerides (25%-72%, P < .0001) and inflammatory cytokines.
Collapse
|
24
|
Oliva J, French SW, Li J, Bardag-Gorce F. Proteasome inhibitor treatment reduced fatty acid, triacylglycerol and cholesterol synthesis. Exp Mol Pathol 2012; 93:26-34. [PMID: 22445925 DOI: 10.1016/j.yexmp.2012.03.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 03/08/2012] [Indexed: 12/20/2022]
Abstract
In the present study, the beneficial effects of proteasome inhibitor treatment in reducing ethanol-induced steatosis were investigated. A microarray analysis was performed on the liver of rats injected with PS-341 (Bortezomib, Velcade), and the results showed that proteasome inhibitor treatment significantly reduced the mRNA expression of SREBP-1c, and the downstream lipogenic enzymes, such as fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC), which catalyzes the carboxylation of acetyl-CoA to malonyl-CoA, the rate-limiting step in fatty acid synthesis. ELOVL6, which is responsible for fatty acids long chain elongation, was also significantly downregulated by proteasome inhibitor treatment. Moreover, PS-341 administration significantly reduced the expression of acyl-glycerol-3-phosphate acyltransferase (AGPAT), and diacylglycerol acyltransferase (DGAT), enzyme involved in triacylglycerol (TAG) synthesis. Finally, PS-341 was found to downregulate the enzyme 3-hydroxy-3-methylglutaryl-CoenzymeA synthase (HMG-CoA synthase) that is responsible for cholesterol synthesis. Proteasome inhibitor was also found to play a role in intestinal lipid adsorption because apolipoproteins A (apoA-I, apoAII, apoA-IV and ApoCIII) were downregulated by proteasome inhibitor treatment, especially ApoA-II that is known to be a marker of alcohol consumption. Proteasome inhibitor treatment also decreased apobec-1 complementation factor (ACF) leading to lower level of editing and production of ApoB protein. Moreover apolipoprotein C-III, a major component of chylomicrons was significantly downregulated. However, lipoprotein lipase (Lpl) and High density lipoprotein binding protein (Hdlbp) mRNA levels were increased by proteasome inhibitor treatment. These results suggested that proteasome inhibitor treatment could be used to reduce the alcohol-enhanced lipogenesis and alcohol-induced liver steatosis. A morphologic analysis, performed on the liver of rats fed ethanol for one month and treated with PS-341, showed that proteasome inhibitor treatment significantly decreased ethanol-induced liver steatosis. SREBP-1c, FAS and ACC were increased by ethanol feeding alone, but were significantly decreased when proteasome inhibitor was administered to rats fed ethanol. Our results also show that both mRNA and protein levels of these lipogenic enzymes, up regulated by ethanol, were then downregulated when proteasome inhibitor was administered to rats fed ethanol. It was also confirmed that alcohol feeding caused an increase in AGPAT and DGAT, which was prevented by proteasome inhibitor treatment of the animal fed ethanol. Chronic alcohol feeding did not affect the gene expression of HMG-CoA synthase. However, PS341 administration significantly reduced the HMG-CoA synthase mRNA levels, confirming the results obtained with the microarray analysis. C/EBP transcription factors alpha (CCAAT/enhancer-binding protein alpha) has been shown to positively regulate SREBP-1c mRNA expression, thus regulating lipogenesis. Proteasome inhibition caused a decrease in C/EBP alpha mRNA expression, indicating that C/EBP downregulation may be the mechanism by which proteasome inhibitor treatment reduced lipogenesis. In conclusion, our results indicate that proteasome activity is not only involved in downregulating fatty acid synthesis and triacylglycerol synthesis, but also cholesterol synthesis and intestinal lipid adsorption. Proteasome inhibitor, administrated at a non-toxic low dose, played a beneficial role in reducing lipogenesis caused by chronic ethanol feeding and these beneficial effects are obtained because of the specificity and reversibility of the proteasome inhibitor used.
Collapse
Affiliation(s)
- Joan Oliva
- Dept. of Pathology, LA BioMed at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
| | | | | | | |
Collapse
|
25
|
Leonard BJ. Nonalcoholic Fatty Liver Disease. Journal of Diagnostic Medical Sonography 2012. [DOI: 10.1177/8756479311429484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is an accumulation of extra fat in the liver cells not caused by alcohol consumption. This disease is an increasingly common condition and the most common cause of abnormal liver function tests among adults. NAFLD is an array of liver diseases ranging from simple hepatic steatosis (fatty liver) to nonalcoholic steatohepatitis (NASH). A liver biopsy is the gold standard for determining hepatic fat content and staging fibrosis. However, the invasiveness of this approach can be a contraindication in certain patients. Noninvasive imaging modalities such as ultrasound, computed tomography (CT), and magnetic resonance (MR) can also detect hepatic fat content.
Collapse
|
26
|
Mells JE, Fu PP, Sharma S, Olson D, Cheng L, Handy JA, Saxena NK, Sorescu D, Anania FA. Glp-1 analog, liraglutide, ameliorates hepatic steatosis and cardiac hypertrophy in C57BL/6J mice fed a Western diet. Am J Physiol Gastrointest Liver Physiol 2012; 302:G225-35. [PMID: 22038829 PMCID: PMC3341115 DOI: 10.1152/ajpgi.00274.2011] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The aims of this study were designed to determine whether liraglutide, a long-acting glucagon-like peptide, could reverse the adverse effects of a diet high in fat that also contained trans-fat and high-fructose corn syrup (ALIOS diet). Specifically, we examined whether treatment with liraglutide could reduce hepatic insulin resistance and steatosis as well as improve cardiac function. Male C57BL/6J mice were pair fed or fed ad libitum either standard chow or the ALIOS diet. After 8 wk the mice were further subdivided and received daily injections of either liraglutide or saline for 4 wk. Hyperinsulinemic-euglycemic clamp studies were performed after 6 wk, revealing hepatic insulin resistance. Glucose tolerance and insulin resistance tests were performed at 8 and 12 wk prior to and following liraglutide treatment. Liver pathology, cardiac measurements, blood chemistry, and RNA and protein analyses were performed. Clamp studies revealed hepatic insulin resistance after 6 wk of ALIOS diet. Liraglutide reduced visceral adiposity and liver weight (P < 0.001). As expected, liraglutide improved glucose and insulin tolerance. Liraglutide improved hypertension (P < 0.05) and reduced cardiac hypertrophy. Surprisingly, liver from liraglutide-treated mice had significantly higher levels of fatty acid binding protein, acyl-CoA oxidase II, very long-chain acyl-CoA dehydrogenase, and microsomal triglyceride transfer protein. We conclude that liraglutide reduces the harmful effects of an ALIOS diet by improving insulin sensitivity and by reducing lipid accumulation in liver through multiple mechanisms including, transport, and increase β-oxidation.
Collapse
Affiliation(s)
- Jamie E. Mells
- 1Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta;
| | - Ping P. Fu
- 1Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta;
| | - Shvetank Sharma
- 1Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta;
| | - Darin Olson
- 2Division of Endocrinology, Metabolism, and Lipids, Department of Medicine, Emory University School of Medicine, Atlanta; and
| | - Lihong Cheng
- 3Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Jeffrey A. Handy
- 1Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta;
| | - Neeraj K. Saxena
- 1Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta;
| | - Dan Sorescu
- 3Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Frank A. Anania
- 1Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta;
| |
Collapse
|
27
|
Nobili V, Sanyal AJ. Treatment of nonalcoholic fatty liver disease in adults and children: a closer look at the arsenal. J Gastroenterol 2012; 47:29-36. [PMID: 21983927 DOI: 10.1007/s00535-011-0467-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 07/28/2011] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease encompasses a spectrum of disease from asymptomatic steatosis, with or without elevated aminotransferases, to cirrhosis with relative complications and hepatocellular carcinoma. Owing to the increasing prevalence of nonalcoholic fatty liver disease and the potential for nonalcoholic steatohepatitis to progress to cirrhosis and liver-related mortality, more research has been focused on therapy of this important liver disease over the last two decades. To date, weight loss and physical activity represent the cornerstone of treatment, with interventions being limited to subjects at risk of disease progression, but the type of treatment remains a matter of debate. A few medications have shown promising results in preliminary pilot studies, but few agents have been tested rigorously. Today, multiple therapeutic approaches are considered the way to go in treating nonalcoholic steatohepatitis patients. In this paper we review the status of current and emerging therapeutic strategies for children and adult patients with nonalcoholic steatohepatitis.
Collapse
Affiliation(s)
- Valerio Nobili
- Unit of Metabolic and Autoimmune Liver Diseases, Pediatric Hospital Bambino Gesù, IRCCS, Square S. Onofrio 4, 00165, Rome, Italy.
| | | |
Collapse
|
28
|
Schrader M, Bonekamp NA, Islinger M. Fission and proliferation of peroxisomes. Biochim Biophys Acta Mol Basis Dis. 2012;1822:1343-1357. [PMID: 22240198 DOI: 10.1016/j.bbadis.2011.12.014] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 12/22/2011] [Accepted: 12/23/2011] [Indexed: 01/12/2023]
Abstract
Peroxisomes are remarkably dynamic, multifunctional organelles, which react to physiological changes in their cellular environment and adopt their morphology, number, enzyme content and metabolic functions accordingly. At the organelle level, the key molecular machinery controlling peroxisomal membrane elongation and remodeling as well as membrane fission is becoming increasingly established and defined. Key players in peroxisome division are conserved in animals, plants and fungi, and key fission components are shared with mitochondria. However, the physiological stimuli and corresponding signal transduction pathways regulating and modulating peroxisome maintenance and proliferation are, despite a few exceptions, largely unexplored. There is emerging evidence that peroxisomal dynamics and proper regulation of peroxisome number and morphology are crucial for the physiology of the cell, as well as for the pathology of the organism. Here, we discuss several key aspects of peroxisomal fission and proliferation and highlight their association with certain diseases. We address signaling and transcriptional events resulting in peroxisome proliferation, and focus on novel findings concerning the key division components and their interplay. Finally, we present an updated model of peroxisomal growth and division. This article is part of a Special Issue entitled: Metabolic Functions and Biogenesis of Peroxisomes in Health and Disease.
Collapse
|
29
|
Abstract
The incidence of nonalcoholic fatty liver disease is steadily increasing among the elderly population. Lipid metabolism is transcriptionally controlled by the nuclear receptors retinoid acid receptor alpha, liver-X-receptor alpha, and peroxisome proliferator-activated receptor alpha and their target genes ABCA1, sterol regulatory element-binding protein-1c, and fatty acid synthase. Using senescence-accelerated prone mice (SAMP8), we addressed the question as to whether age-related increase of oxidative stress affects nuclear receptor gene expression. In contrast to SAMR1 control mice, young SAMP8 mice exhibit hepatic steatosis with increased hepatic cholesterol content, plasma triglyceride, and aspartate aminotransferase levels. This is accompanied by an increase of liver-X-receptor alpha and retinoid acid receptor alpha expression, whereas peroxisome proliferator-activated receptor alpha expression is found diminished. SAMP8 mice further reveal a lower expression of ABCA1 as well as of sterol regulatory element-binding protein-1c and higher expression of fatty acid synthase. The dysbalance between the nuclear receptors and their target genes most probably mediates hepatic steatosis and underlines the pathological relevance of nuclear receptor shift toward lipogenesis in fat metabolism of the elderly patient.
Collapse
Affiliation(s)
- Angela Kuhla
- Institute for Experimental Surgery, University of Rostock, Schillingallee 69a, D-18057 Rostock, Germany
| | | | | | | |
Collapse
|
30
|
Abstract
AIM Hepatic steatosis accompanied by impaired protein synthesis is often observed in hepatic dysfunction. To assess whether protein synthesis inhibition directly induces hepatic steatosis, we investigated the molecular mechanisms of cycloheximide (CHX)-induced fatty liver mice. METHODS C57/BL6CR mice were i.p. administrated CHX (20 mg/kg) three times every 4 h to induce hepatic steatosis. Hepatic lipid secretion, fatty acid oxidation, hepatic lipogenesis and hepatic lipid uptake were evaluated. RESULTS Twenty-four hours after the first CHX injection, hepatic lipid levels increased in CHX-treated mice to 1.8-fold of that in controls but returned to normal within 48 h. The hepatic triglyceride (TG) secretion rate decreased significantly to 22% of controls, and the apolipoprotein B (apoB) protein level, but not microsomal TG transfer protein, decreased in CHX-treated mice. The apob gene expression was not significantly different between controls and CHX-treated mice. On the other hand, plasma free fatty acid and lipogenic protein levels did not increase and plasma β-hydroxybutyrate level remained stable, suggesting that the coordinated balance between fatty acid oxidation, hepatic lipid uptake and lipogenesis was not disrupted in this model. Cellular lipid accumulation and decreased cellular and secreted apoB were also observed in CHX-treated HepG2 cells. Knockdown of apoB in HepG2 cells also resulted in the cellular TG accumulation. CONCLUSION We demonstrated that decreased hepatic lipid secretion due to acute apoB reduction is involved in the pathogenesis of CHX-induced liver steatosis.
Collapse
Affiliation(s)
- Mari Murakami
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita Department of Pediatrics, Setsunan General Hospital, Kadoma, Osaka, Japan Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | | | | | | | | | | |
Collapse
|
31
|
Hiramine Y, Imamura Y, Uto H, Koriyama C, Horiuchi M, Oketani M, Hosoyamada K, Kusano K, Ido A, Tsubouchi H. Alcohol drinking patterns and the risk of fatty liver in Japanese men. J Gastroenterol 2011; 46:519-28. [PMID: 20967556 DOI: 10.1007/s00535-010-0336-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 09/21/2010] [Indexed: 02/04/2023]
Abstract
BACKGROUND Alcohol is considered to be a major cause of fatty liver (FL). In contrast, however, recent investigations have suggested that moderate alcohol consumption is protective against FL. To clarify the role of alcohol consumption in FL development, we examined the association between drinking patterns and FL prevalence. METHODS We enrolled 9,886 male participants at regular medical health checks. Each subject's history of alcohol consumption was determined by questionnaire. The subjects were classified according to alcohol consumption as non-, light, moderate, and heavy drinkers (0, <20, 20-59, and ≥60 g/day, respectively). FL was defined by ultrasonography. Independent predictors of FL were determined by logistic regression analysis. RESULTS The prevalence of FL displayed a "U-shaped curve" across the categories of daily alcohol consumption (non-, 44.7%; light, 39.3%; moderate, 35.9%; heavy drinkers, 40.1%; P < 0.001). The prevalence of FL was associated positively with body mass index and other obesity-related diseases and inversely with alcohol consumption (light, odds ratio [OR] 0.71, 95% confidence interval [CI] 0.59-0.86; moderate, OR 0.55, CI 0.45-0.67; heavy, OR 0.44, CI 0.32-0.62) as determined by multivariate analysis after adjusting for potential confounding variables. In addition, examination of drinking patterns (frequency and volume) revealed that the prevalence of FL was inversely associated with the frequency of alcohol consumption (≥21 days/month) (OR 0.62, CI 0.53-0.71) but not with the volume of alcohol consumed. CONCLUSIONS Our observations suggest that alcohol consumption plays a protective role against FL in men, and consistent alcohol consumption may contribute to this favorable effect.
Collapse
|
32
|
Yamamoto K, Takahara K, Oyadomari S, Okada T, Sato T, Harada A, Mori K. Induction of liver steatosis and lipid droplet formation in ATF6alpha-knockout mice burdened with pharmacological endoplasmic reticulum stress. Mol Biol Cell 2010; 21:2975-86. [PMID: 20631254 PMCID: PMC2929991 DOI: 10.1091/mbc.e09-02-0133] [Citation(s) in RCA: 224] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We burdened mice with intraperitoneal injection of the endoplasmic reticulum stress-inducing reagent tunicamycin, and found that wild-type mice were able to recover from the insult, whereas ATF6α-knockout mice exhibited liver dysfunction and steatosis. Our results establish links between endoplasmic reticulum stress, lipid metabolism and steatosis Accumulation of unfolded proteins in the endoplasmic reticulum (ER) activates homeostatic responses collectively termed the unfolded protein response. Among the three principal signaling pathways operating in mammals, activating transcription factor (ATF)6α plays a pivotal role in transcriptional induction of ER-localized molecular chaperones and folding enzymes as well as components of ER-associated degradation, and thereby mouse embryonic fibroblasts deficient in ATF6α are sensitive to ER stress. However, ATF6α-knockout mice show no apparent phenotype under normal growing conditions. In this report, we burdened mice with intraperitoneal injection of the ER stress-inducing reagent tunicamycin and found that wild-type mice were able to recover from the insult, whereas ATF6α-knockout mice exhibited liver dysfunction and steatosis. Thus, ATF6α-knockout mice accumulated neutral lipids in the liver such as triacylglycerol and cholesterol, which was ascribable to blockage of β-oxidation of fatty acids caused by decreased mRNA levels of the enzymes involved in the process, suppression of very-low-density lipoprotein formation due to destabilized apolipoprotein B-100, and stimulation of lipid droplet formation resulting from transcriptional induction of adipose differentiation-related protein. Accordingly, the hepatocytes of tunicamycin-injected knockout mice were filled with many lipid droplets. These results establish links among ER stress, lipid metabolism, and steatosis.
Collapse
Affiliation(s)
- Keisuke Yamamoto
- *Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | | | | | | | | | | | | |
Collapse
|
33
|
Sanal MG, Sarin SK. Serum adipokine profile in Indian men with nonalcoholic steatohepatitis: Serum adiponectin is paradoxically decreased in lean vs. obese patients. Diabetes Metab Syndr 2009. [DOI: 10.1016/j.dsx.2009.07.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
34
|
Current Opinion in Endocrinology, Diabetes & Obesity. Current world literature. Curr Opin Endocrinol Diabetes Obes 2009; 16:189-202. [PMID: 19300094 DOI: 10.1097/MED.0b013e328329fcc2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
35
|
Paschos P, Paletas K. Non alcoholic fatty liver disease and metabolic syndrome. Hippokratia 2009; 13:9-19. [PMID: 19240815 PMCID: PMC2633261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a clinicopathologic entity increasingly recognized as a major health burden in developed countries. It includes a spectrum of liver damage ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), advanced fibrosis, and rarely, progression to cirrhosis. Recent studies emphasize the role of insulin resistance, oxidative stress and subsequent lipid peroxidation, proinflammatory cytokines, adipokines and mitochondrial dysfunction in the development and progression of NAFLD. Furthermore, accumulating evidence supports an association between NAFLD and metabolic syndrome. Although the data are mainly epidemiological, the pathogenesis of NAFLD and metabolic syndrome seems to have common pathophysiological mechanisms, with focus on insulin resistance as a key factor. This review summarizes the current knowledge on the epidemiology, pathophysiology and diagnosis of both NAFLD and metabolic syndrome and the findings that strongly support the association of nonalcoholic fatty liver disease as a possible component in the cluster of metabolic syndrome.
Collapse
Affiliation(s)
- P Paschos
- Metabolic Disease Unit, 2nd Internal Medicine Department, Aristotle University of Thessaloniki, Hippokratio Hospital, Thessaloniki, Greece
| | | |
Collapse
|
36
|
Mueller AS, Klomann SD, Wolf NM, Schneider S, Schmidt R, Spielmann J, Stangl G, Eder K, Pallauf J. Redox regulation of protein tyrosine phosphatase 1B by manipulation of dietary selenium affects the triglyceride concentration in rat liver. J Nutr 2008; 138:2328-36. [PMID: 19022953 DOI: 10.3945/jn.108.089482] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Protein tyrosine phosphatase 1B (PTP1B) is a key enzyme in the counter-regulation of insulin signaling and in the stimulation of fatty acid synthesis. Selenium (Se), via the activities of glutathione peroxidase (GPx) and thioredoxin reductase (TrxR), is involved in the removal of H(2)O(2) and organic peroxides, which are critical compounds in the modulation of PTP1B activity via glutathionylation. Our study with growing rats investigated how the manipulation of dietary Se concentration influences the regulation of PTP1B and lipogenic effects mediated by PTP1B. Weanling albino rats were divided into 3 groups of 10. The negative control group (NC) was fed a Se-deficient diet for 8 wk. Rats in groups Se75 and Se150 received diets supplemented with 75 or 150 microg Se/kg. Se supplementation of the rats strongly influenced expression and activity of the selenoenzymes cytosolic GPx, plasma GPx, phospholipidhydroperoxide GPx, and cytosolic TrxR, and liver PTP1B. Liver PTP1B activity was significantly higher in groups Se75 and Se150 than in the NC group and this was attributed to a lowered inhibition of the enzyme by glutathionylation. The increased liver PTP1B activity in groups Se75 and Se150 resulted in 1.1- and 1.4-fold higher liver triglyceride concentrations than in the NC rats. The upregulation of the sterol regulatory element binding protein-1c and of fatty acid synthase, 2 PTP1B targets, provided a possible explanation for the lipogenic effect of PTP1B due to the manipulation of dietary Se. We therefore conclude that redox-regulated proteins, such as PTP1B, represent important interfaces between dietary antioxidants such as Se and the regulation of metabolic processes.
Collapse
Affiliation(s)
- Andreas S Mueller
- Institute of Agricultural and Nutritional Sciences, Preventive Nutrition Group, Martin Luther University Halle Wittenberg, Halle, Saale, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Sanal MG. Adipose tissue transplantation may be a potential treatment for diabetes, atherosclerosis and nonalcoholic steatohepatitis. Med Hypotheses 2008; 72:247-9. [PMID: 19046821 DOI: 10.1016/j.mehy.2008.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2008] [Revised: 10/05/2008] [Accepted: 10/13/2008] [Indexed: 01/09/2023]
Abstract
Adipose tissue is critical in energy homeostasis. Adipose tissue 'buffers' the lipids and energy rich compounds which are pumped into the blood stream soon after meals. It senses, signals other organs like liver and brain about the energy reserves via adipokines. Adiponectin, the most abundant adipokine has insulin sensitizing, anti-inflammatory antiatherogenic and antisteatotic effects. Adipose tissue dysfunction is accompanied by abnormal lipid distribution and storage which contributes to diseases like diabetes, nonalcoholic fatty liver disease and atherosclerosis. Obesity and lipodystrophy are associated with dysfunctional adipocytes. Pre-adipocytes are easy to isolate and culture. A personalized depot specific liposuction to remove the inactive adipocytes followed by adipocyte repopulation could be useful in the treatment of these diseases.
Collapse
|