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Li T, Jin Y, Wu J, Ren Z. Beyond energy provider: multifunction of lipid droplets in embryonic development. Biol Res 2023; 56:38. [PMID: 37438836 DOI: 10.1186/s40659-023-00449-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 06/23/2023] [Indexed: 07/14/2023] Open
Abstract
Since the discovery, lipid droplets (LDs) have been recognized to be sites of cellular energy reserves, providing energy when necessary to sustain cellular life activities. Many studies have reported large numbers of LDs in eggs and early embryos from insects to mammals. The questions of how LDs are formed, what role they play, and what their significance is for embryonic development have been attracting the attention of researchers. Studies in recent years have revealed that in addition to providing energy for embryonic development, LDs in eggs and embryos also function to resist lipotoxicity, resist oxidative stress, inhibit bacterial infection, and provide lipid and membrane components for embryonic development. Removal of LDs from fertilized eggs or early embryos artificially leads to embryonic developmental arrest and defects. This paper reviews recent studies to explain the role and effect mechanisms of LDs in the embryonic development of several species and the genes involved in the regulation. The review contributes to understanding the embryonic development mechanism and provides new insight for the diagnosis and treatment of diseases related to embryonic developmental abnormalities.
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Affiliation(s)
- Tai Li
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of the Ministry of Education & Key Laboratory of Swine Genetics and Breeding of the Ministry of Agriculture and Rural Affairs, College of Animal Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, P. R. China
| | - Yi Jin
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of the Ministry of Education & Key Laboratory of Swine Genetics and Breeding of the Ministry of Agriculture and Rural Affairs, College of Animal Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, P. R. China
| | - Jian Wu
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of the Ministry of Education & Key Laboratory of Swine Genetics and Breeding of the Ministry of Agriculture and Rural Affairs, College of Animal Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, P. R. China
- Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan, 430070, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Zhuqing Ren
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of the Ministry of Education & Key Laboratory of Swine Genetics and Breeding of the Ministry of Agriculture and Rural Affairs, College of Animal Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, P. R. China.
- Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan, 430070, China.
- Hubei Hongshan Laboratory, Wuhan, China.
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2
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Kakiyama G, Rodriguez-Agudo D, Pandak WM. Mitochondrial Cholesterol Metabolites in a Bile Acid Synthetic Pathway Drive Nonalcoholic Fatty Liver Disease: A Revised "Two-Hit" Hypothesis. Cells 2023; 12:1434. [PMID: 37408268 DOI: 10.3390/cells12101434] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 07/07/2023] Open
Abstract
The rising prevalence of nonalcoholic fatty liver disease (NAFLD)-related cirrhosis highlights the need for a better understanding of the molecular mechanisms responsible for driving the transition of hepatic steatosis (fatty liver; NAFL) to steatohepatitis (NASH) and fibrosis/cirrhosis. Obesity-related insulin resistance (IR) is a well-known hallmark of early NAFLD progression, yet the mechanism linking aberrant insulin signaling to hepatocyte inflammation has remained unclear. Recently, as a function of more distinctly defining the regulation of mechanistic pathways, hepatocyte toxicity as mediated by hepatic free cholesterol and its metabolites has emerged as fundamental to the subsequent necroinflammation/fibrosis characteristics of NASH. More specifically, aberrant hepatocyte insulin signaling, as found with IR, leads to dysregulation in bile acid biosynthetic pathways with the subsequent intracellular accumulation of mitochondrial CYP27A1-derived cholesterol metabolites, (25R)26-hydroxycholesterol and 3β-Hydroxy-5-cholesten-(25R)26-oic acid, which appear to be responsible for driving hepatocyte toxicity. These findings bring forth a "two-hit" interpretation as to how NAFL progresses to NAFLD: abnormal hepatocyte insulin signaling, as occurs with IR, develops as a "first hit" that sequentially drives the accumulation of toxic CYP27A1-driven cholesterol metabolites as the "second hit". In the following review, we examine the mechanistic pathway by which mitochondria-derived cholesterol metabolites drive the development of NASH. Insights into mechanistic approaches for effective NASH intervention are provided.
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Affiliation(s)
- Genta Kakiyama
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, VA 23249, USA
| | - Daniel Rodriguez-Agudo
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, VA 23249, USA
| | - William M Pandak
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
- Research Services, Central Virginia Veterans Affairs Healthcare System, Richmond, VA 23249, USA
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3
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Rojas Á, Lara-Romero C, Muñoz-Hernández R, Gato S, Ampuero J, Romero-Gómez M. Emerging pharmacological treatment options for MAFLD. Ther Adv Endocrinol Metab 2022; 13:20420188221142452. [PMID: 36533188 PMCID: PMC9747889 DOI: 10.1177/20420188221142452] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 11/13/2022] [Indexed: 12/14/2022] Open
Abstract
Metabolic dysfunction-associated fatty liver disease (MAFLD) prevalence and incidence is rising globally. It is associated with metabolic comorbidities, obesity, overweight, type 2 diabetes mellitus, and at least two metabolic risk factors, such as hypertension, hypertriglyceridemia, hypercholesterolemia, insulin resistance, and cardiovascular risk, increasing the risk of mortality. The excessive accumulation of fat comprises apoptosis, necrosis, inflammation and ballooning degeneration progressing to fibrosis, cirrhosis, and liver decompensations including hepatocellular carcinoma development. The limitation of approved drugs to prevent MAFLD progression is a paradigm. This review focuses on recent pathways and targets with evidence results in phase II/III clinical trials.
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Affiliation(s)
- Ángela Rojas
- SeLiver Group, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Calle Antonio Maura Montaner s/n, 41013 Sevilla, Spain
- Hepatic and Digestive Diseases Networking Biomedical Research Centre (CIBERehd), Av. Monforte de Lemos, 3-5. Pabellón 11, Planta 0 28029 Madrid, Madrid, Spain
| | - Carmen Lara-Romero
- SeLiver Group, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
- Digestive Diseases Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain
| | - Rocío Muñoz-Hernández
- SeLiver Group, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
- Hepatic and Digestive Diseases Networking Biomedical Research Centre (CIBERehd), Madrid, Spain
| | - Sheila Gato
- SeLiver Group, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
- Hepatic and Digestive Diseases Networking Biomedical Research Centre (CIBERehd), Madrid, Spain
| | - Javier Ampuero
- SeLiver Group, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
- Hepatic and Digestive Diseases Networking Biomedical Research Centre (CIBERehd), Madrid, Spain
- Digestive Diseases Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain
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Horn CL, Morales AL, Savard C, Farrell GC, Ioannou GN. Role of Cholesterol-Associated Steatohepatitis in the Development of NASH. Hepatol Commun 2021; 6:12-35. [PMID: 34558856 PMCID: PMC8710790 DOI: 10.1002/hep4.1801] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 07/08/2021] [Accepted: 07/14/2021] [Indexed: 12/11/2022] Open
Abstract
The rising prevalence of nonalcoholic fatty liver disease (NAFLD) and NAFLD-related cirrhosis in the United States and globally highlights the need to better understand the mechanisms causing progression of hepatic steatosis to fibrosing steatohepatitis and cirrhosis in a small proportion of patients with NAFLD. Accumulating evidence suggests that lipotoxicity mediated by hepatic free cholesterol (FC) overload is a mechanistic driver for necroinflammation and fibrosis, characteristic of nonalcoholic steatohepatitis (NASH), in many animal models and also in some patients with NASH. Diet, lifestyle, obesity, key genetic polymorphisms, and hyperinsulinemia secondary to insulin resistance are pivotal drivers leading to aberrant cholesterol signaling, which leads to accumulation of FC within hepatocytes. FC overload in hepatocytes can lead to ER stress, mitochondrial dysfunction, development of toxic oxysterols, and cholesterol crystallization in lipid droplets, which in turn lead to hepatocyte apoptosis, necrosis, or pyroptosis. Activation of Kupffer cells and hepatic stellate cells by hepatocyte signaling and cholesterol loading contributes to this inflammation and leads to hepatic fibrosis. Cholesterol accumulation in hepatocytes can be readily prevented or reversed by statins. Observational studies suggest that use of statins in NASH not only decreases the substantially increased cardiovascular risk, but may ameliorate liver pathology. Conclusion: Hepatic FC loading may result in cholesterol-associated steatohepatitis and play an important role in the development and progression of NASH. Statins appear to provide significant benefit in preventing progression to NASH and NASH-cirrhosis. Randomized controlled trials are needed to demonstrate whether statins or statin/ezetimibe combination can effectively reverse steatohepatitis and liver fibrosis in patients with NASH.
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Affiliation(s)
- Christian L Horn
- Division of Gastroenterology and Hepatology, Department of Medicine, San Antonio Military Medical Center, Fort Sam Houston, TX, USA
| | - Amilcar L Morales
- Division of Gastroenterology and Hepatology, Department of Medicine, San Antonio Military Medical Center, Fort Sam Houston, TX, USA
| | - Christopher Savard
- Division of Gastroenterology, Department of Medicine, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA.,Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, WA, USA.,Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
| | - Geoffrey C Farrell
- Liver Research Group, ANU Medical School, Australian National University at the Canberra Hospital, Garran, ACT, Australia
| | - George N Ioannou
- Division of Gastroenterology, Department of Medicine, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA.,Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, WA, USA.,Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
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5
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Di Ciaula A, Passarella S, Shanmugam H, Noviello M, Bonfrate L, Wang DQH, Portincasa P. Nonalcoholic Fatty Liver Disease (NAFLD). Mitochondria as Players and Targets of Therapies? Int J Mol Sci 2021; 22:ijms22105375. [PMID: 34065331 PMCID: PMC8160908 DOI: 10.3390/ijms22105375] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 12/12/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and represents the hepatic expression of several metabolic abnormalities of high epidemiologic relevance. Fat accumulation in the hepatocytes results in cellular fragility and risk of progression toward necroinflammation, i.e., nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Several pathways contribute to fat accumulation and damage in the liver and can also involve the mitochondria, whose functional integrity is essential to maintain liver bioenergetics. In NAFLD/NASH, both structural and functional mitochondrial abnormalities occur and can involve mitochondrial electron transport chain, decreased mitochondrial β-oxidation of free fatty acids, excessive generation of reactive oxygen species, and lipid peroxidation. NASH is a major target of therapy, but there is no established single or combined treatment so far. Notably, translational and clinical studies point to mitochondria as future therapeutic targets in NAFLD since the prevention of mitochondrial damage could improve liver bioenergetics.
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Affiliation(s)
- Agostino Di Ciaula
- Department of Biomedical Sciences & Human Oncology, Clinica Medica “A. Murri”, University of Bari Medical School, 70124 Bari, Italy; (A.D.C.); (H.S.); (M.N.); (L.B.)
| | - Salvatore Passarella
- School of Medicine, University of Bari Medical School, 70124 Bari, Italy
- Correspondence: (S.P.); (P.P.); Tel.: +39-328-468-7215 (P.P.)
| | - Harshitha Shanmugam
- Department of Biomedical Sciences & Human Oncology, Clinica Medica “A. Murri”, University of Bari Medical School, 70124 Bari, Italy; (A.D.C.); (H.S.); (M.N.); (L.B.)
| | - Marica Noviello
- Department of Biomedical Sciences & Human Oncology, Clinica Medica “A. Murri”, University of Bari Medical School, 70124 Bari, Italy; (A.D.C.); (H.S.); (M.N.); (L.B.)
| | - Leonilde Bonfrate
- Department of Biomedical Sciences & Human Oncology, Clinica Medica “A. Murri”, University of Bari Medical School, 70124 Bari, Italy; (A.D.C.); (H.S.); (M.N.); (L.B.)
| | - David Q.-H. Wang
- Department of Medicine and Genetics, Division of Gastroenterology and Liver Diseases, Marion Bessin Liver Research Center, Einstein-Mount Sinai Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
| | - Piero Portincasa
- Department of Biomedical Sciences & Human Oncology, Clinica Medica “A. Murri”, University of Bari Medical School, 70124 Bari, Italy; (A.D.C.); (H.S.); (M.N.); (L.B.)
- Correspondence: (S.P.); (P.P.); Tel.: +39-328-468-7215 (P.P.)
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Grattagliano I, Di Ciaula A, Baj J, Molina-Molina E, Shanmugam H, Garruti G, Wang DQH, Portincasa P. Protocols for Mitochondria as the Target of Pharmacological Therapy in the Context of Nonalcoholic Fatty Liver Disease (NAFLD). Methods Mol Biol 2021; 2310:201-246. [PMID: 34096005 PMCID: PMC8580566 DOI: 10.1007/978-1-0716-1433-4_12] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is one of the most frequent metabolic chronic liver diseases in developed countries and puts the populations at risk of progression to liver necro-inflammation, fibrosis, cirrhosis, and hepatocellular carcinoma. Mitochondrial dysfunction is involved in the onset of NAFLD and contributes to the progression from NAFLD to nonalcoholic steatohepatitis (NASH). Thus, liver mitochondria could become the target for treatments for improving liver function in NAFLD patients. This chapter describes the most important steps used for potential therapeutic interventions in NAFLD patients, discusses current options gathered from both experimental and clinical evidence, and presents some novel options for potentially improving mitochondrial function in NAFLD.
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Affiliation(s)
- Ignazio Grattagliano
- Clinica Medica "A. Murri", Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, Bari, Italy
- Italian College of General Practitioners and Primary Care, Bari, Italy
| | - Agostino Di Ciaula
- Clinica Medica "A. Murri", Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, Bari, Italy
| | - Jacek Baj
- Department of Anatomy, Medical University of Lublin, Lublin, Poland
| | - Emilio Molina-Molina
- Clinica Medica "A. Murri", Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, Bari, Italy
| | - Harshitha Shanmugam
- Clinica Medica "A. Murri", Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, Bari, Italy
| | - Gabriella Garruti
- Section of Endocrinology, Department of Emergency and Organ Transplantations, University of Bari "Aldo Moro" Medical School, Bari, Italy
| | - David Q-H Wang
- Division of Gastroenterology and Liver Diseases, Department of Medicine and Genetics, Marion Bessin Liver Research Center, Einstein-Mount Sinai Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Piero Portincasa
- Clinica Medica "A. Murri", Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, Bari, Italy.
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Di Ciaula A, Baj J, Garruti G, Celano G, De Angelis M, Wang HH, Di Palo DM, Bonfrate L, Wang DQH, Portincasa P. Liver Steatosis, Gut-Liver Axis, Microbiome and Environmental Factors. A Never-Ending Bidirectional Cross-Talk. J Clin Med 2020; 9:E2648. [PMID: 32823983 PMCID: PMC7465294 DOI: 10.3390/jcm9082648] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/07/2020] [Accepted: 08/12/2020] [Indexed: 02/07/2023] Open
Abstract
The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide and parallels comorbidities such as obesity, metabolic syndrome, dyslipidemia, and diabetes. Recent studies describe the presence of NAFLD in non-obese individuals, with mechanisms partially independent from excessive caloric intake. Increasing evidences, in particular, point towards a close interaction between dietary and environmental factors (including food contaminants), gut, blood flow, and liver metabolism, with pathways involving intestinal permeability, the composition of gut microbiota, bacterial products, immunity, local, and systemic inflammation. These factors play a critical role in the maintenance of intestinal, liver, and metabolic homeostasis. An anomalous or imbalanced gut microbial composition may favor an increased intestinal permeability, predisposing to portal translocation of microorganisms, microbial products, and cell wall components. These components form microbial-associated molecular patterns (MAMPs) or pathogen-associated molecular patterns (PAMPs), with potentials to interact in the intestine lamina propria enriched in immune cells, and in the liver at the level of the immune cells, i.e., Kupffer cells and stellate cells. The resulting inflammatory environment ultimately leads to liver fibrosis with potentials to progression towards necrotic and fibrotic changes, cirrhosis. and hepatocellular carcinoma. By contrast, measures able to modulate the composition of gut microbiota and to preserve gut vascular barrier might prevent or reverse NAFLD.
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Affiliation(s)
- Agostino Di Ciaula
- Clinica Medica “A. Murri”, Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, 70124 Bari, Italy; (A.D.C.); (D.M.D.P.); (L.B.)
| | - Jacek Baj
- Department of Anatomy, Medical University of Lublin, 20-090 Lublin, Poland;
| | - Gabriella Garruti
- Section of Endocrinology, Department of Emergency and Organ Transplantations, University of Bari “Aldo Moro” Medical School, Piazza G. Cesare 11, 70124 Bari, Italy;
| | - Giuseppe Celano
- Dipartimento di Scienze del Suolo, della Pianta e Degli Alimenti, Università degli Studi di Bari Aldo Moro, 70124 Bari, Italy; (G.C.); (M.D.A.)
| | - Maria De Angelis
- Dipartimento di Scienze del Suolo, della Pianta e Degli Alimenti, Università degli Studi di Bari Aldo Moro, 70124 Bari, Italy; (G.C.); (M.D.A.)
| | - Helen H. Wang
- Department of Medicine and Genetics, Division of Gastroenterology and Liver Diseases, Marion Bessin Liver Research Center, Einstein-Mount Sinai Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (H.H.W.); (D.Q.-H.W.)
| | - Domenica Maria Di Palo
- Clinica Medica “A. Murri”, Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, 70124 Bari, Italy; (A.D.C.); (D.M.D.P.); (L.B.)
- Dipartimento di Scienze del Suolo, della Pianta e Degli Alimenti, Università degli Studi di Bari Aldo Moro, 70124 Bari, Italy; (G.C.); (M.D.A.)
| | - Leonilde Bonfrate
- Clinica Medica “A. Murri”, Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, 70124 Bari, Italy; (A.D.C.); (D.M.D.P.); (L.B.)
| | - David Q-H Wang
- Department of Medicine and Genetics, Division of Gastroenterology and Liver Diseases, Marion Bessin Liver Research Center, Einstein-Mount Sinai Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (H.H.W.); (D.Q.-H.W.)
| | - Piero Portincasa
- Clinica Medica “A. Murri”, Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, 70124 Bari, Italy; (A.D.C.); (D.M.D.P.); (L.B.)
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8
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Zehra M, Curry JC, Pillai SS, Lakhani HV, Edwards CE, Sodhi K. Elucidating Potential Profibrotic Mechanisms of Emerging Biomarkers for Early Prognosis of Hepatic Fibrosis. Int J Mol Sci 2020; 21:E4737. [PMID: 32635162 DOI: 10.3390/ijms21134737] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
Hepatic fibrosis has been associated with a series of pathophysiological processes causing excessive accumulation of extracellular matrix proteins. Several cellular processes and molecular mechanisms have been implicated in the diseased liver that augments fibrogenesis, fibrogenic cytokines and associated liver complications. Liver biopsy remains an essential diagnostic tool for histological evaluation of hepatic fibrosis to establish a prognosis. In addition to being invasive, this methodology presents with several limitations including poor cost-effectiveness, prolonged hospitalizations, and risks of peritoneal bleeding, while the clinical use of this method does not reveal underlying pathogenic mechanisms. Several alternate noninvasive diagnostic strategies have been developed, to determine the extent of hepatic fibrosis, including the use of direct and indirect biomarkers. Immediate diagnosis of hepatic fibrosis by noninvasive means would be more palatable than a biopsy and could assist clinicians in taking early interventions timely, avoiding fatal complications, and improving prognosis. Therefore, we sought to review some common biomarkers of liver fibrosis along with some emerging candidates, including the oxidative stress-mediated biomarkers, epigenetic and genetic markers, exosomes, and miRNAs that needs further evaluation and would have better sensitivity and specificity. We also aim to elucidate the potential role of cardiotonic steroids (CTS) and evaluate the pro-inflammatory and profibrotic effects of CTS in exacerbating hepatic fibrosis. By understanding the underlying pathogenic processes, the efficacy of these biomarkers could allow for early diagnosis and treatment of hepatic fibrosis in chronic liver diseases, once validated.
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Henkel J, Buchheim-Dieckow K, Castro JP, Laeger T, Wardelmann K, Kleinridders A, Jöhrens K, Püschel GP. Reduced Oxidative Stress and Enhanced FGF21 Formation in Livers of Endurance-Exercised Rats with Diet-Induced NASH. Nutrients 2019; 11:E2709. [PMID: 31717358 DOI: 10.3390/nu11112709] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/31/2019] [Accepted: 11/05/2019] [Indexed: 01/08/2023] Open
Abstract
Non-alcoholic fatty liver diseases (NAFLD) including the severe form with steatohepatitis (NASH) are highly prevalent ailments to which no approved pharmacological treatment exists. Dietary intervention aiming at 10% weight reduction is efficient but fails due to low compliance. Increase in physical activity is an alternative that improved NAFLD even in the absence of weight reduction. The underlying mechanisms are unclear and cannot be studied in humans. Here, a rat NAFLD model was developed that reproduces many facets of the diet-induced NAFLD in humans. The impact of endurance exercise was studied in this model. Male Wistar rats received control chow or a NASH-inducing diet rich in fat, cholesterol, and fructose. Both diet groups were subdivided into a sedentary and an endurance exercise group. Animals receiving the NASH-inducing diet gained more body weight, got glucose intolerant and developed a liver pathology with steatosis, hepatocyte hypertrophy, inflammation and fibrosis typical of NAFLD or NASH. Contrary to expectations, endurance exercise did not improve the NASH activity score and even enhanced hepatic inflammation. However, endurance exercise attenuated the hepatic cholesterol overload and the ensuing severe oxidative stress. In addition, exercise improved glucose tolerance possibly in part by induction of hepatic FGF21 production.
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Abstract
The liver constantly adapts to meet energy requirements of the whole body. Despite its remarkable adaptative capacity, prolonged exposure of liver cells to harmful environmental cues (such as diets rich in fat, sugar, and cholesterol) results in the development of chronic liver diseases (including non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH)) that can progress to hepatocellular carcinoma (HCC). The pathogenesis of these diseases is extremely complex, multifactorial, and poorly understood. Emerging evidence suggests that mitochondrial dysfunction or maladaptation contributes to detrimental effects on hepatocyte bioenergetics, reactive oxygen species (ROS) homeostasis, endoplasmic reticulum (ER) stress, inflammation, and cell death leading to NASH and HCC. The present review highlights the potential contribution of altered mitochondria function to NASH-related HCC and discusses how agents targeting this organelle could provide interesting treatment strategies for these diseases.
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Affiliation(s)
- Mélissa Léveillé
- Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, QC H2W 1R7, Canada.
- Faculty of Medicine, University of Montreal, Montreal, Quebec, QC H3G 2M1, Canada.
| | - Jennifer L Estall
- Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, QC H2W 1R7, Canada.
- Faculty of Medicine, University of Montreal, Montreal, Quebec, QC H3G 2M1, Canada.
- Division of Experimental Medicine, McGill University, Montreal, Quebec, QC H4A 3J1, Canada.
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11
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Dias IH, Borah K, Amin B, Griffiths HR, Sassi K, Lizard G, Iriondo A, Martinez-Lage P. Localisation of oxysterols at the sub-cellular level and in biological fluids. J Steroid Biochem Mol Biol 2019; 193:105426. [PMID: 31301352 DOI: 10.1016/j.jsbmb.2019.105426] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/25/2019] [Accepted: 07/09/2019] [Indexed: 12/16/2022]
Abstract
Oxysterols are oxidized derivatives of cholesterol that are formed enzymatically or via reactive oxygen species or both. Cholesterol or oxysterols ingested as food are absorbed and packed into lipoproteins that are taken up by hepatic cells. Within hepatic cells, excess cholesterol is metabolised to form bile acids. The endoplasmic reticulum acts as the main organelle in the bile acid synthesis pathway. Metabolised sterols originating from this pathway are distributed within other organelles and in the cell membrane. The alterations to membrane oxysterol:sterol ratio affects the integrity of the cell membrane. The presence of oxysterols changes membrane fluidity and receptor orientation. It is well documented that hydroxylase enzymes located in mitochondria facilitate oxysterol production via an acidic pathway. More recently, the presence of oxysterols was also reported in lysosomes. Peroxisomal deficiencies favour intracellular oxysterols accumulation. Despite the low abundance of oxysterols compared to cholesterol, the biological actions of oxysterols are numerous and important. Oxysterol levels are implicated in the pathogenesis of multiple diseases ranging from chronic inflammatory diseases (atherosclerosis, Alzheimer's disease and bowel disease), cancer and numerous neurodegenerative diseases. In this article, we review the distribution of oxysterols in sub-cellular organelles and in biological fluids.
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Affiliation(s)
- Irundika Hk Dias
- Aston Medical Research Institute, Aston Medical School, Aston University, Birmingham, B4 7ET, UK.
| | - Khushboo Borah
- Faculty of Health and Medical Sciences, University of Surrey, Stag Hill, Guildford, GU2 7XH, UK
| | - Berivan Amin
- Aston Medical Research Institute, Aston Medical School, Aston University, Birmingham, B4 7ET, UK
| | - Helen R Griffiths
- Aston Medical Research Institute, Aston Medical School, Aston University, Birmingham, B4 7ET, UK; Faculty of Health and Medical Sciences, University of Surrey, Stag Hill, Guildford, GU2 7XH, UK
| | - Khouloud Sassi
- Team Bio-PeroxIL, Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism (EA7270)/University Bourgogne Franche-Comté/Inserm, 21000 Dijon, France; Univ. Tunis El Manar, Laboratory of Onco-Hematology (LR05ES05), Faculty of Medicine, Tunis, Tunisia
| | - Gérard Lizard
- Team Bio-PeroxIL, Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism (EA7270)/University Bourgogne Franche-Comté/Inserm, 21000 Dijon, France
| | - Ane Iriondo
- Department of Neurology, Center for Research and Advanced Therapies, CITA-Alzheimer Foundation, San Sebastian, Spain
| | - Pablo Martinez-Lage
- Department of Neurology, Center for Research and Advanced Therapies, CITA-Alzheimer Foundation, San Sebastian, Spain
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12
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Wang S, Yang FJ, Shang LC, Zhang YH, Zhou Y, Shi XL. Puerarin protects against high-fat high-sucrose diet-induced non-alcoholic fatty liver disease by modulating PARP-1/PI3K/AKT signaling pathway and facilitating mitochondrial homeostasis. Phytother Res 2019; 33:2347-2359. [PMID: 31273855 DOI: 10.1002/ptr.6417] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [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: 09/18/2018] [Revised: 04/27/2019] [Accepted: 05/26/2019] [Indexed: 12/11/2022]
Abstract
As yet, there was no effective pharmacological therapy approved for non-alcoholic fatty liver disease (NAFLD). Here, we aimed to evaluate the therapeutic potential of puerarin against NAFLD and explored the underlying mechanisms. C57BL/6J mice were fed with a high-fat high-sucrose (HFHS) diet with or without puerarin coadministration intragastrically. The levels of hepatocellular injury, steatosis, fibrosis, and mitochondrial and metabolism alteration were detected. First, puerarin ameliorated histopathologic abnormalities due to HFHS. We observed a marked increase in hepatic lipid content, inflammation, and fibrosis level, which were attenuated by puerarin. Possible mechanisms were related to puerarin-mediated activation of PI3K/AKT pathway and further improvement in fatty acid metabolism. Puerarin restored the NAD+ content and beneficially affected the hepatic mitochondrial function, which attenuated HFHS-induced steatosis and metabolic disturbances. Finally, hepatic PARP-1 was activated due to excessive fat intake. Puerarin attenuated the PARP-1 expression in HFHS-fed mice, and PJ34, the PARP inhibitor, could mimic these protections of puerarin. However, pharmacological inhibition of PI3K disabled the protection of puerarin or PJ34 toward NAD+ refilling and mitochondrial homeostasis. In conclusion, our findings indicated that puerarin could be a promising and practical therapeutic strategy in NAFLD through modulating PARP-1/PI3K/AKT signaling pathway and further facilitating mitochondrial function.
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Affiliation(s)
- Shuai Wang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Fa-Ji Yang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Long-Cheng Shang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yu-Heng Zhang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yuan Zhou
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Xiao-Lei Shi
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
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13
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Abstract
It is increasingly accepted that dietary cholesterol has a much lower impact on the progression of cardiovascular disease than previously assumed. However, both animal experiments and human studies seem to support the view that dietary cholesterol may contribute to the transition from benign steatosis to the potentially fatal non-alcoholic steatohepatitis. Cholesterol esters and cholesterol accumulate in the hepatocyte and impair its function. This leads to oxidative stress and endoplasmic reticulum stress triggering the release of pro-inflammatory cytokines and rendering the hepatocyte more susceptible to apoptotic or necrotic cell death. Kupffer cells group around dying hepatocytes and phagocytose the hepatocyte debris and lipids. In addition, they are exposed to lipid peroxidation products released from hepatocytes. Kupffer cells, thus activated, release pro-inflammatory, chemotactic and profibrotic cytokines that promote inflammation and fibrosis. Therefore, dietary cholesterol may be harmful to the liver, in particular when administered in combination with polyunsaturated fatty acids that favor lipid peroxidation.
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Affiliation(s)
- Gerhard P Püschel
- Department of Nutritional Biochemistry, University of Potsdam, Institute of Nutritional Science, Nuthetal, Germany
| | - Janin Henkel
- Department of Nutritional Biochemistry, University of Potsdam, Institute of Nutritional Science, Nuthetal, Germany
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14
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Ma X, Cheng F, Yuan K, Jiang K, Zhu T. Lipid storage droplet protein 5 reduces sodium palmitate‑induced lipotoxicity in human normal liver cells by regulating lipid metabolism‑related factors. Mol Med Rep 2019; 20:879-886. [PMID: 31173228 PMCID: PMC6625193 DOI: 10.3892/mmr.2019.10360] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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] [Received: 04/24/2018] [Accepted: 11/28/2018] [Indexed: 12/13/2022] Open
Abstract
Lipid storage droplet protein 5 (LSDP5) is specifically expressed in tissues with high oxidative metabolism such as liver and heart. The present study aimed to explored the role of LSDP5 in sodium palmitate-induced lipotoxicity in LO2 normal human liver cells. LO2 cells were treated with various concentrations of sodium palmitate (25, 50, 75, 100, 125 and 150 µmol/l) for 12, 24 and 48 h, and cell viability was determined by Cell Counting Kit-8. Subsequently, LO2 cells were exposed to 100 µmol/l sodium palmitate for 48 h to induce lipotoxicity (Model). Lipotoxicity Model LO2 cells were also transfected with pCMV5-LSDP5 overexpression vector, and reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP) and apoptotic rates were measured. The contents of non-esterified fatty acid (NEFA), malondialdehyde (MDA) and superoxide dismutase (SOD) were also measured. The expression levels of LSDP5, and apoptosis-, mitochondrial-, lipid metabolism-related factors were detected using reverse transcription-quantitative polymerase chain reaction and western blot assays. The results indicated that sodium palmitate exposure inhibited cell viability and induced lipotoxicity in LO2 cells. LSDP5 overexpression decreased ROS and apoptotic rates, and reduced NEFA and MDA content. LSDP5 transfection rescued the loss of MMP and elevated SOD content in lipotoxicity Model LO2 cells. In addition, LSDP5 upregulated the expression levels of B-cell lymphoma-2, acetyl-CoA carboxylase1/2 and fatty acid synthase (Fas), whereas the expression levels of activated-caspase-3, Bcl-2-associated X protein, cytochrome c, cytochrome c oxidase subunits IV, carnitine palmitoyltransferase 1a and peroxisome proliferator-activated receptors α levels were downregulated. LSDP5 may produce a protective effect on sodium palmitate-induced lipotoxicity in LO2 cells by regulating lipid metabolism-related factors.
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Affiliation(s)
- Xueqiang Ma
- Department of Hepatobiliary Surgery, Zhuji People's Hospital of Zhejiang Province, Zhuji, Zhejiang 311800, P.R. China
| | - Feiyong Cheng
- Department of Hepatobiliary Surgery, Zhuji People's Hospital of Zhejiang Province, Zhuji, Zhejiang 311800, P.R. China
| | - Keyu Yuan
- Department of Hepatobiliary Surgery, Zhuji People's Hospital of Zhejiang Province, Zhuji, Zhejiang 311800, P.R. China
| | - Kexiang Jiang
- Department of Hepatobiliary Surgery, Zhuji People's Hospital of Zhejiang Province, Zhuji, Zhejiang 311800, P.R. China
| | - Tieming Zhu
- Department of Hepatobiliary Surgery, Zhuji People's Hospital of Zhejiang Province, Zhuji, Zhejiang 311800, P.R. China
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15
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Abstract
Non-alcoholic fatty liver disease (NAFLD) spectrum comprises simple steatosis and non-alcoholic steatohepatitis (NASH) that can lead to fibrosis and cirrhosis. The patients usually have no history of excessive alcohol consumption and other etiologies that can cause fatty liver. Understanding of the pathophysiology of NAFLD has revealed that non-coding RNAs (ncRNAs) play significant roles in modulating the disease susceptibility, pathogenesis and progression. Currently, the ncRNAs are grouped according to their sizes and their regulatory or housekeeping functions. Each of these ncRNAs has a wide range of involvement in the regulation of the genes and biological pathways. Here, we briefly review the current literature the regulatory ncRNAs in NAFLD pathogenesis and progression, mainly the microRNAs, long non-coding RNAs and circular RNAs. We also discuss the co-regulatory functions and interactions between these ncRNAs in modulating the disease pathogenesis. Elucidation of ncRNAs in NAFLD may facilitate the identification of early diagnostic biomarkers and development of therapeutic strategies for NAFLD.
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Affiliation(s)
- Siti Aishah Sulaiman
- UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
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16
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Henkel J, Alfine E, Saín J, Jöhrens K, Weber D, Castro JP, König J, Stuhlmann C, Vahrenbrink M, Jonas W, Kleinridders A, Püschel GP. Soybean Oil-Derived Poly-Unsaturated Fatty Acids Enhance Liver Damage in NAFLD Induced by Dietary Cholesterol. Nutrients 2018; 10:nu10091326. [PMID: 30231595 PMCID: PMC6164134 DOI: 10.3390/nu10091326] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 09/14/2018] [Accepted: 09/14/2018] [Indexed: 12/12/2022] Open
Abstract
While the impact of dietary cholesterol on the progression of atherosclerosis has probably been overestimated, increasing evidence suggests that dietary cholesterol might favor the transition from blunt steatosis to non-alcoholic steatohepatitis (NASH), especially in combination with high fat diets. It is poorly understood how cholesterol alone or in combination with other dietary lipid components contributes to the development of lipotoxicity. The current study demonstrated that liver damage caused by dietary cholesterol in mice was strongly enhanced by a high fat diet containing soybean oil-derived ω6-poly-unsaturated fatty acids (ω6-PUFA), but not by a lard-based high fat diet containing mainly saturated fatty acids. In contrast to the lard-based diet the soybean oil-based diet augmented cholesterol accumulation in hepatocytes, presumably by impairing cholesterol-eliminating pathways. The soybean oil-based diet enhanced cholesterol-induced mitochondrial damage and amplified the ensuing oxidative stress, probably by peroxidation of poly-unsaturated fatty acids. This resulted in hepatocyte death, recruitment of inflammatory cells, and fibrosis, and caused a transition from steatosis to NASH, doubling the NASH activity score. Thus, the recommendation to reduce cholesterol intake, in particular in diets rich in ω6-PUFA, although not necessary to reduce the risk of atherosclerosis, might be sensible for patients suffering from non-alcoholic fatty liver disease.
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Affiliation(s)
- Janin Henkel
- Department of Nutritional Biochemistry, Institute of Nutritional Science, University of Potsdam, D-14558 Nuthetal, Germany.
| | - Eugenia Alfine
- German Institute of Human Nutrition, Junior Research Group Central Regulation of Metabolism; D-14558 Nuthetal, Germany.
- German Center for Diabetes Research (DZD), D-85764 München-Neuherberg, Germany.
| | - Juliana Saín
- Department of Nutritional Biochemistry, Institute of Nutritional Science, University of Potsdam, D-14558 Nuthetal, Germany.
- Department of Biological Sciences, Food Science and Nutrition, Faculty of Biochemistry and Biological Sciences, National University of the Litoral (UNL), Santa Fe S3000, Argentina.
| | - Korinna Jöhrens
- Institute of Pathology, Carl Gustav Carus University Hospital Dresden; D-01307 Dresden, Germany.
| | - Daniela Weber
- Department of Molecular Toxicology, German Institute of Human Nutrition; D-14558 Nuthetal, Germany.
| | - José P Castro
- Department of Molecular Toxicology, German Institute of Human Nutrition; D-14558 Nuthetal, Germany.
- Department of Medicine, Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| | - Jeannette König
- Department of Molecular Toxicology, German Institute of Human Nutrition; D-14558 Nuthetal, Germany.
| | - Christin Stuhlmann
- Department of Nutritional Biochemistry, Institute of Nutritional Science, University of Potsdam, D-14558 Nuthetal, Germany.
| | - Madita Vahrenbrink
- Department of Nutritional Biochemistry, Institute of Nutritional Science, University of Potsdam, D-14558 Nuthetal, Germany.
| | - Wenke Jonas
- German Center for Diabetes Research (DZD), D-85764 München-Neuherberg, Germany.
- Department of Experimental Diabetology, German Institute of Human Nutrition; D-14558 Nuthetal, Germany.
| | - André Kleinridders
- German Institute of Human Nutrition, Junior Research Group Central Regulation of Metabolism; D-14558 Nuthetal, Germany.
- German Center for Diabetes Research (DZD), D-85764 München-Neuherberg, Germany.
| | - Gerhard P Püschel
- Department of Nutritional Biochemistry, Institute of Nutritional Science, University of Potsdam, D-14558 Nuthetal, Germany.
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17
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Mendez-Sanchez N, Cruz-Ramon VC, Ramirez-Perez OL, Hwang JP, Barranco-Fragoso B, Cordova-Gallardo J. New Aspects of Lipotoxicity in Nonalcoholic Steatohepatitis. Int J Mol Sci 2018; 19:E2034. [PMID: 30011790 PMCID: PMC6073816 DOI: 10.3390/ijms19072034] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/09/2018] [Accepted: 07/11/2018] [Indexed: 02/08/2023] Open
Abstract
NASH is becoming increasingly common worldwide because of the growing global prevalence of obesity and consequently NAFLD. Unfortunately, the mechanism of progression of NAFLD to NASH and then cirrhosis is not completely understood. Several factors, including insulin resistance, inflammation, oxidative stress, lipotoxicity, and bile acid (BA) toxicity, have been reported to be associated with NASH progression. The release of fatty acids from dysfunctional and insulin-resistant adipocytes results in lipotoxicity, which is caused by the ectopic accumulation of triglyceride-derived toxic metabolites and the subsequent activation of inflammatory pathways, cellular dysfunction, and lipoapoptosis. Adipose tissue (AT), especially visceral AT, comprises multiple cell populations that produce adipokines and insulin-like growth factor, plus macrophages and other immune cells that stimulate the development of lipotoxic liver disease. These biomolecules have been recently linked with many digestive diseases and gastrointestinal malignancies such as hepatocellular carcinoma. This made us question what role lipotoxicity has in the natural history of liver fibrosis. Therefore, this review focuses on the close relationship between AT and NASH. A good comprehension of the pathways that are related to dysregulated AT, metabolic dysfunction, and hepatic lipotoxicity will result in the development of prevention strategies and promising therapeutics for patients with NASH.
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Affiliation(s)
| | | | | | - Jessica P Hwang
- Department of General Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
| | - Beatriz Barranco-Fragoso
- Department of Gastroenterology, National Medical Center "20 Noviembre", 03229 Mexico City, Mexico.
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18
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Tirosh O. Hypoxic Signaling and Cholesterol Lipotoxicity in Fatty Liver Disease Progression. Oxid Med Cell Longev 2018; 2018:2548154. [PMID: 29955245 DOI: 10.1155/2018/2548154] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/30/2018] [Accepted: 05/14/2018] [Indexed: 02/06/2023]
Abstract
Cholesterol is the only lipid whose absorption in the gastrointestinal tract is limited by gate-keeping transporters and efflux mechanisms, preventing its rapid absorption and accumulation in the liver and blood vessels. In this review, I explored the current data regarding cholesterol accumulation in liver cells and key mechanisms in cholesterol-induced fatty liver disease associated with the activation of deleterious hypoxic and nitric oxide signal transduction pathways. Although nonalcoholic fatty liver disease (NAFLD) affects both obese and nonobese individuals, the mechanism of NAFLD progression in lean individuals with healthy metabolism is puzzling. Lean NAFLD individuals exhibit normal metabolic responses, implying that liver damage is not associated with impaired metabolism per se and that direct lipotoxic effects are crucial for disease progression. Several redox and oxidant signaling pathways involving cholesterol are at play in fatty liver disease development. These include impairment of the mitochondrial and lysosomal function by cholesterol loading of the inner-cell membranes; formation of cholesterol crystals and hepatocyte degradation; and crown-like structures surrounding degrading hepatocytes, activating Kupffer cells, and evoking inflammation. The current review focuses on the induction of liver inflammation, fibrosis, and steatosis by free cholesterol via the hypoxia-inducible factor 1α (HIF-1α), a main oxygen-sensing transcription factor involved in all stages of NAFLD. Cholesterol loading in hepatocytes can result in chronic HIF-1α activity because of the decreased oxygen availability and excessive production of nitric oxide and mitochondrial reactive oxygen species.
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19
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Tamura S, Okada M, Kato S, Shinoda Y, Shioda N, Fukunaga K, Ui-Tei K, Ueda M. Ouabagenin is a naturally occurring LXR ligand without causing hepatic steatosis as a side effect. Sci Rep 2018; 8:2305. [PMID: 29396543 PMCID: PMC5797171 DOI: 10.1038/s41598-018-20663-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [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] [Received: 09/04/2017] [Accepted: 01/23/2018] [Indexed: 12/23/2022] Open
Abstract
Ouabagenin (OBG) is an aglycone of the cardiotonic steroid ouabain and until now was considered a biologically inactive biosynthetic precursor. Herein, we revealed that OBG functions as a novel class of ligand for the liver X receptor (LXR). Luciferase reporter assays and in silico docking studies suggested that OBG has LXR-selective agonistic activity. In addition, OBG repressed the expression of epithelial sodium channel (ENaC), a LXR target gene, without causing hepatic steatosis, a typical side effect of conventional LXR ligands. This remarkable biological activity can be attributed to a unique mode of action; the LXR agonist activity mainly proceeds through the LXRβ subtype without affecting LXRα, unlike conventional LXR ligands. Thus, OBG is a novel class of LXR ligand that does not cause severe side effects, with potential for use as an antihypertensive diuretic or a tool compound for exploring LXR subtype-specific biological functions.
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Affiliation(s)
- Satoru Tamura
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, 980-8578, Japan.,School of Pharmacy, Iwate Medical University, Shiwa-gun, Iwate, 028-3694, Japan
| | - Maiko Okada
- Institute of Medical Science, St. Marianna University Graduate School of Medicine, Kawasaki, Kanagawa, 970-8551, Japan.,Genome regulation and Molecular Pharmacogenomics, School of Bioscience and Biotechnology, Tokyo University of Technology, Hachioji, Tokyo, 192-0982, Japan
| | - Shigeaki Kato
- Iwaki Meisei University, Iwaki, Fukushima, 970-8551, Japan.,Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, 972-8322, Japan
| | - Yasuharu Shinoda
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, 980-8578, Japan
| | - Norifumi Shioda
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, 980-8578, Japan
| | - Kohji Fukunaga
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, 980-8578, Japan
| | - Kumiko Ui-Tei
- Graduate School of Science, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Minoru Ueda
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, 980-8578, Japan.
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20
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Abstract
The pathogenesis of non-alcoholic fatty liver disease, particularly the mechanisms whereby a minority of patients develop a more severe phenotype characterised by hepatocellular damage, inflammation, and fibrosis is still incompletely understood. Herein, we discuss two pivotal aspects of the pathogenesis of NASH. We first analyse the initial mechanisms responsible for hepatocellular damage and inflammation, which derive from the toxic effects of excess lipids. Accumulating data indicate that the total amount of triglycerides stored in hepatocytes is not the major determinant of lipotoxicity, and that specific lipid classes act as damaging agents on liver cells. In particular, the role of free fatty acids such as palmitic acid, cholesterol, lysophosphatidylcholine and ceramides has recently emerged. These lipotoxic agents affect the cell behaviour via multiple mechanisms, including activation of signalling cascades and death receptors, endoplasmic reticulum stress, modification of mitochondrial function, and oxidative stress. In the second part of this review, the cellular and molecular players involved in the cross-talk between the gut and the liver are considered. These include modifications to the microbiota, which provide signals through the intestine and bacterial products, as well as hormones produced in the bowel that affect metabolism at different levels including the liver. Finally, the activation of nuclear receptors by bile acids is analysed.
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Affiliation(s)
- Fabio Marra
- Dipartimento di Medicina Sperimentale e Clinica and Centro di Ricerca Denothe, Università di Firenze, Italy.
| | - Gianluca Svegliati-Baroni
- Dipartimento Scienze Cliniche e Molecolari, Università Politecnica delle Marche, Ancona, Italy; Centro Interdipartimentale Obesità, Università Politecnica delle Marche, Ancona, Italy
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21
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Musman J, Paradis S, Panel M, Pons S, Barau C, Caccia C, Leoni V, Ghaleh B, Morin D. A TSPO ligand prevents mitochondrial sterol accumulation and dysfunction during myocardial ischemia-reperfusion in hypercholesterolemic rats. Biochem Pharmacol 2017. [DOI: 10.1016/j.bcp.2017.06.125] [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] [Indexed: 12/12/2022]
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22
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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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23
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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: 330] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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24
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Ande SR, Nguyen KH, Grégoire Nyomba BL, Mishra S. Prohibitin-induced, obesity-associated insulin resistance and accompanying low-grade inflammation causes NASH and HCC. Sci Rep 2016; 6:23608. [PMID: 27005704 PMCID: PMC4804274 DOI: 10.1038/srep23608] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [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: 11/15/2015] [Accepted: 03/10/2016] [Indexed: 02/08/2023] Open
Abstract
Obesity increases the risk for nonalcoholic steatohepatitis (NASH) and hepatocarcinogenesis. However, the underlying mechanisms involved in the disease process remain unclear. Recently, we have developed a transgenic obese mouse model (Mito-Ob) by prohibitin mediated mitochondrial remodeling in adipocytes. The Mito-Ob mice develop obesity in a sex-neutral manner, but obesity-associated adipose inflammation and metabolic dysregulation in a male sex-specific manner. Here we report that with aging, the male Mito-Ob mice spontaneously develop obesity-linked NASH and hepatocellular carcinoma (HCC). In contrast, the female Mito-Ob mice maintained normal glucose and insulin levels and did not develop NASH and HCC. The anti-inflammatory peptide ghrelin was significantly upregulated in the female mice and down regulated in the male mice compared with respective control mice. In addition, a reduction in the markers of mitochondrial content and function was found in the liver of male Mito-Ob mice with NASH/HCC development. We found that ERK1/2 signaling was significantly upregulated whereas STAT3 signaling was significantly down regulated in the tumors from Mito-Ob mice. These data provide a proof-of-concept that the metabolic and inflammatory status of the adipose tissue and their interplay at the systemic and hepatic level play a central role in the pathogenesis of obesity-linked NASH and HCC.
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Affiliation(s)
- Sudharsana R. Ande
- Department of Internal Medicine, University of Manitoba, Winnipeg, Canada
| | - K. Hoa Nguyen
- Department of Internal Medicine, University of Manitoba, Winnipeg, Canada
| | | | - Suresh Mishra
- Department of Internal Medicine, University of Manitoba, Winnipeg, Canada
- Department of Physiology & Pathophysiology, University of Manitoba, Winnipeg, Canada
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