1
|
Lu Y, Yu B, Bu Y, Lou J, Jin Y. Pegbelfermin for reducing transaminase levels in patients with non-alcoholic steatohepatitis: a dose-response meta-analysis of randomized controlled trials. Front Med (Lausanne) 2024; 11:1293336. [PMID: 38646552 PMCID: PMC11026620 DOI: 10.3389/fmed.2024.1293336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 03/25/2024] [Indexed: 04/23/2024] Open
Abstract
Background The efficacy of Pegbelfermin (PGBF) in treating non-alcoholic steatohepatitis (NASH) remains controversial. Therefore, we conducted a dose-response meta-analysis to explore the effect and pattern of PGBF at different dosages and treatment durations on transaminase reduction in NASH patients. Methods We conducted searches on PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov, and supplemented the search with gray literature and manual searches. Randomized controlled trials (RCTs) evaluating the efficacy of PGBF in NASH patients were included. Risk of bias was assessed by Cochrane Risk of Bias Tool 2.0. We used random-effects models, generalized least squares regression, constrained maximum likelihood, and restricted cubic splines to explore the dose-response relationship. Egger's linear regression was employed to assess publication bias. The study is registered with PROSPERO, CRD42023448024. Results Four RCT studies from the period 2018-2023, involving 546 participants, were included. No participants discontinued PGBF treatment due to adverse events. High-dose PGBF treatment significantly reduced transaminase levels in NASH patients compared to the low-dose group (ALT %: MD = 14.94, 95% CI = 2.11-27.77; AST %: MD = 9.05, 95% CI = 3.17-14.92). Longer treatment duration further decreased transaminase levels (ALT%: MD = 8.81, 95% CI = 4.07-13.56; AST%: MD = 6.72, 95% CI = 2.62-10.81). Egger's test did not reveal significant publication bias (p > 0.05). Further investigation indicated a ceiling effect of PGBF dosage on transaminase reduction at 30 mg/week, and NASH patients experienced a rebound in transaminase levels after 28 weeks of continuous treatment. Conclusion There is a positive correlation between PGBF dosage and transaminase reduction within a certain range, showing an overall non-linear dose-response relationship. This finding provides guidance for the clinical application of PGBF. Clinicians should be mindful of the dosage ceiling at 30 mg/week and monitor changes in transaminase levels after 28 weeks for timely adjustments in PGBF dosage. Systematic review registration PROSPERO, CRD42023448024. https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=448024.
Collapse
Affiliation(s)
- Yangguang Lu
- The First School of Medicine, School of Information and Engineering, Wenzhou Medical University, Wenzhou, China
| | - Bohuai Yu
- The First School of Medicine, School of Information and Engineering, Wenzhou Medical University, Wenzhou, China
| | - Yiran Bu
- The First School of Medicine, School of Information and Engineering, Wenzhou Medical University, Wenzhou, China
| | - Jialing Lou
- The First School of Medicine, School of Information and Engineering, Wenzhou Medical University, Wenzhou, China
| | - Yan Jin
- Department of Infectious Diseases, Tongde Hospital of Zhejiang Province, Hangzhou, China
| |
Collapse
|
2
|
Townsend LK, Steinberg GR. AMPK and the Endocrine Control of Metabolism. Endocr Rev 2023; 44:910-933. [PMID: 37115289 DOI: 10.1210/endrev/bnad012] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/10/2023] [Accepted: 04/24/2023] [Indexed: 04/29/2023]
Abstract
Complex multicellular organisms require a coordinated response from multiple tissues to maintain whole-body homeostasis in the face of energetic stressors such as fasting, cold, and exercise. It is also essential that energy is stored efficiently with feeding and the chronic nutrient surplus that occurs with obesity. Mammals have adapted several endocrine signals that regulate metabolism in response to changes in nutrient availability and energy demand. These include hormones altered by fasting and refeeding including insulin, glucagon, glucagon-like peptide-1, catecholamines, ghrelin, and fibroblast growth factor 21; adipokines such as leptin and adiponectin; cell stress-induced cytokines like tumor necrosis factor alpha and growth differentiating factor 15, and lastly exerkines such as interleukin-6 and irisin. Over the last 2 decades, it has become apparent that many of these endocrine factors control metabolism by regulating the activity of the AMPK (adenosine monophosphate-activated protein kinase). AMPK is a master regulator of nutrient homeostasis, phosphorylating over 100 distinct substrates that are critical for controlling autophagy, carbohydrate, fatty acid, cholesterol, and protein metabolism. In this review, we discuss how AMPK integrates endocrine signals to maintain energy balance in response to diverse homeostatic challenges. We also present some considerations with respect to experimental design which should enhance reproducibility and the fidelity of the conclusions.
Collapse
Affiliation(s)
- Logan K Townsend
- Centre for Metabolism Obesity and Diabetes Research, Hamilton, ON L8S 4L8, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Gregory R Steinberg
- Centre for Metabolism Obesity and Diabetes Research, Hamilton, ON L8S 4L8, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| |
Collapse
|
3
|
Oey O, Sunjaya AF, Khan Y, Redfern A. Stromal inflammation, fibrosis and cancer: An old intuition with promising potential. World J Clin Oncol 2023; 14:230-246. [PMID: 37583950 PMCID: PMC10424089 DOI: 10.5306/wjco.v14.i7.230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/07/2023] [Accepted: 06/21/2023] [Indexed: 07/19/2023] Open
Abstract
It is now well established that the biology of cancer is influenced by not only malignant cells but also other components of the tumour microenvironment. Chronic inflammation and fibrosis have long been postulated to be involved in carcinogenesis. Chronic inflammation can promote tumorigenesis via growth factor/cytokine-mediated cellular proliferation, apoptotic resistance, immunosuppression; and free-radical-induced oxidative deoxyribonucleic acid damage. Fibrosis could cause a perturbation in the dynamics of the tumour microenvironment, potentially damaging the genome surveillance machinery of normal epithelial cells. In this review, we will provide an in-depth discussion of various diseases characterised by inflammation and fibrosis that have been associated with an increased risk of malignancy. In particular, we will present a comprehensive overview of the impact of alterations in stromal composition on tumorigenesis, induced as a consequence of inflammation and/or fibrosis. Strategies including the application of various therapeutic agents with stromal manipulation potential and targeted cancer screening for certain inflammatory diseases which can reduce the risk of cancer will also be discussed.
Collapse
Affiliation(s)
- Oliver Oey
- Faculty of Medicine, University of Western Australia, Perth 6009, Crawley NA, Australia
- Department of Medical Oncology, Sir Charles Gardner Hospital, Nedlands 6009, Australia
| | - Angela Felicia Sunjaya
- Institute of Cardiovascular Science, University College London, London WC1E 6DD, United Kingdom
| | - Yasir Khan
- Department of Medical Oncology, St John of God Midland Public and Private Hospital, Midland 6056, WA, Australia
| | - Andrew Redfern
- Department of Medical Oncology, Fiona Stanley Hospital, Murdoch 6150, WA, Australia
| |
Collapse
|
4
|
Luo L, Liu M. Adiponectin: friend or foe in obesity and inflammation. MEDICAL REVIEW (2021) 2022; 2:349-362. [PMID: 37724325 PMCID: PMC10388816 DOI: 10.1515/mr-2022-0002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/27/2022] [Indexed: 09/20/2023]
Abstract
Adiponectin is an adipokine predominantly produced by fat cells, circulates and exerts insulin-sensitizing, cardioprotective and anti-inflammatory effects. Dysregulation of adiponectin and/or adiponectin signaling is implicated in a number of metabolic diseases such as obesity, insulin resistance, diabetes, and cardiovascular diseases. However, while the insulin-sensitizing and cardioprotective effects of adiponectin have been widely appreciated in the field, the obesogenic and anti-inflammatory effects of adiponectin are still of much debate. Understanding the physiological function of adiponectin is critical for adiponectin-based therapeutics for the treatment of metabolic diseases.
Collapse
Affiliation(s)
- Liping Luo
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Meilian Liu
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| |
Collapse
|
5
|
Perilipin 2 Protects against Lipotoxicity-Induced Islet Fibrosis by Inducing Islet Stellate Cell Activation Phenotype Changes. BIOMED RESEARCH INTERNATIONAL 2022; 2022:4581405. [PMID: 35845956 PMCID: PMC9279040 DOI: 10.1155/2022/4581405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 06/20/2022] [Indexed: 11/17/2022]
Abstract
Aims We explored whether and how perilipin 2 (Plin2) protected islets against lipotoxicity-induced islet dysfunction by regulating islet stellate cells (ISCs) activation. Methods Six-week-old male rats were given a high-fat diet or a control diet for 28 weeks. Glucose metabolic phenotypes were assessed using glucose/insulin tolerance tests, masson, and immunohistochemical staining. ISCs activation levels were assessed from rats and palmitic acid- (PA-) treated cultured ISCs by immunofluorescence, Oil red O staining, electron microscopy, quantitative PCR, and western blotting. Changes in ISCs phenotype of activation degree and its underlying mechanisms were assessed by target gene lentiviral infection, high-performance liquid chromatography (HPLC), and western blotting. Results Obese rats showed glucose intolerance, decreased endocrine hormone profiles, and elevated expression of α-smooth muscle actin (α-SMA), a polygonal appearance without cytoplasmic lipid droplets of ISCs in rats and isolated islets. PA-treated cultured ISCs exhibited faster proliferation and migration abilities with the induction of mRNA levels of lipid metabolism proteins, especially Plin2. The overexpression of Plin2 resulted in ISCs “re-quiescent” phenotypes associated with inhibition of the Smad3-TGF-β signaling pathways. Conclusions Our observations suggest a protective role of Plin2 in weakening ISCs activation. It may serve as a novel therapeutic target for preventing islet fibrosis for T2DM.
Collapse
|
6
|
Harrison SA, Ruane PJ, Freilich BL, Neff G, Patil R, Behling CA, Hu C, Fong E, de Temple B, Tillman EJ, Rolph TP, Cheng A, Yale K. Efruxifermin in non-alcoholic steatohepatitis: a randomized, double-blind, placebo-controlled, phase 2a trial. Nat Med 2021; 27:1262-1271. [PMID: 34239138 DOI: 10.1038/s41591-021-01425-3] [Citation(s) in RCA: 151] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 06/02/2021] [Indexed: 02/04/2023]
Abstract
Preclinical and clinical data suggest that fibroblast growth factor 21 (FGF21) is anti-fibrotic, improves metabolic status and has potential to treat non-alcoholic steatohepatitis (NASH). We assessed the safety and efficacy of efruxifermin, a long-acting Fc-FGF21 fusion protein, for the treatment of NASH. BALANCED was a randomized, placebo-controlled study in patients with NASH conducted at 27 centers in the United States (ClinicalTrials.gov NCT03976401 ). Eighty patients, stratified by hepatic fat fraction (HFF) and fibrosis stage, were randomized using a centrally administered minimization algorithm 1:1:1:1 to receive placebo (n = 21) or efruxifermin 28 mg (n = 19), efruxifermin 50 mg (n = 20) or efruxifermin 70 mg (n = 20) via weekly subcutaneous injection for 16 weeks. The primary endpoint-absolute change from baseline in HFF measured as magnetic resonance imaging-proton density fat fraction at week 12-was met. For the full analysis set, the least squares mean absolute changes (one-sided 97.5% confidence interval) from baseline in HFF were -12.3% (-infinity (-inf), -10.3), -13.4% (-inf, -11.4) and -14.1% (-inf, -12.1) in the 28-, 50- and 70-mg groups, respectively, versus 0.3% (-inf, 1.6) in the placebo group, with statistically significant differences between efruxifermin groups and placebo (P < 0.0001 each). Overall, 70 of 79 patients who received the study drug (89%) experienced at least one treatment-emergent adverse event (TEAE), with the majority grade 1-2 (64 (81%)), five (6%) grade 3 and one grade 4. The most commonly reported drug-related TEAEs were grade 1-2 gastrointestinal (36 (46%)). Treatment with efruxifermin significantly reduced HFF in patients with F1-F3 stage NASH, with an acceptable safety profile.
Collapse
Affiliation(s)
| | | | | | - Guy Neff
- Covenant Research, LLC, Sarasota, FL, USA
| | | | - Cynthia A Behling
- NAFLD Research Center, Division of Gastroenterology, University of California, San Diego, San Diego CA, USA
| | - Chen Hu
- Medpace, Inc., Cincinnati, OH, USA
| | - Erica Fong
- Akero Therapeutics, South San Francisco, CA, USA
| | | | | | | | - Andrew Cheng
- Akero Therapeutics, South San Francisco, CA, USA
| | - Kitty Yale
- Akero Therapeutics, South San Francisco, CA, USA.
| |
Collapse
|
7
|
Li N, Zhao S, Zhang Z, Zhu Y, Gliniak CM, Vishvanath L, An YA, Wang MY, Deng Y, Zhu Q, Shan B, Sherwood A, Onodera T, Oz OK, Gordillo R, Gupta RK, Liu M, Horvath TL, Dixit VD, Scherer PE. Adiponectin preserves metabolic fitness during aging. eLife 2021; 10:65108. [PMID: 33904399 PMCID: PMC8099426 DOI: 10.7554/elife.65108] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 04/22/2021] [Indexed: 02/07/2023] Open
Abstract
Adiponectin is essential for the regulation of tissue substrate utilization and systemic insulin sensitivity. Clinical studies have suggested a positive association of circulating adiponectin with healthspan and lifespan. However, the direct effects of adiponectin on promoting healthspan and lifespan remain unexplored. Here, we are using an adiponectin null mouse and a transgenic adiponectin overexpression model. We directly assessed the effects of circulating adiponectin on the aging process and found that adiponectin null mice display exacerbated age-related glucose and lipid metabolism disorders. Moreover, adiponectin null mice have a significantly shortened lifespan on both chow and high-fat diet. In contrast, a transgenic mouse model with elevated circulating adiponectin levels has a dramatically improved systemic insulin sensitivity, reduced age-related tissue inflammation and fibrosis, and a prolonged healthspan and median lifespan. These results support a role of adiponectin as an essential regulator for healthspan and lifespan.
Collapse
Affiliation(s)
- Na Li
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States.,Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Shangang Zhao
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Zhuzhen Zhang
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Yi Zhu
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Christy M Gliniak
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Lavanya Vishvanath
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Yu A An
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - May-Yun Wang
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Yingfeng Deng
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Qingzhang Zhu
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Bo Shan
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Amber Sherwood
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Toshiharu Onodera
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Orhan K Oz
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Ruth Gordillo
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Rana K Gupta
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Tamas L Horvath
- Department of Comparative Medicine and Immunobiology, Yale School of Medicine, New Haven, United States
| | - Vishwa Deep Dixit
- Department of Comparative Medicine and Immunobiology, Yale School of Medicine, New Haven, United States.,Yale Center for Research on Aging, Yale School of Medicine, New Haven, United States
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, United States
| |
Collapse
|
8
|
Kaufman A, Abuqayyas L, Denney WS, Tillman EJ, Rolph T. AKR-001, an Fc-FGF21 Analog, Showed Sustained Pharmacodynamic Effects on Insulin Sensitivity and Lipid Metabolism in Type 2 Diabetes Patients. Cell Rep Med 2020; 1:100057. [PMID: 33205064 PMCID: PMC7659583 DOI: 10.1016/j.xcrm.2020.100057] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 05/04/2020] [Accepted: 06/23/2020] [Indexed: 12/18/2022]
Abstract
Experimental fibroblast growth factor 21 (FGF21) analogs can improve lipid profiles in patients with metabolic diseases. However, their effects on markers of insulin sensitivity appear to be minimal, potentially because of insufficient exposure. Systemic drug levels vary from sub-pharmacological to demonstrating pharmacodynamic effects but with dose-limiting adverse events. Here we report results from a phase 1 multiple ascending dose study of AKR-001, an Fc-FGF21 fusion protein engineered for sustained systemic pharmacologic exposure, in individuals with type 2 diabetes. With a half-life of 3-3.5 days, the peak-to-trough ratio under steady-state conditions is approximately 2 following QW dosing. AKR-001 appears to demonstrate pharmacodynamic effects on serum markers of insulin sensitivity and acceptable tolerability up to and including 70 mg QW. Positive trends in lipoprotein profile, including triglycerides, non-high-density lipoprotein (non-HDL) cholesterol, HDL-C, and apolipoproteins B and C3 are consistent with other FGF21 analogs. AKR-001's clinical profile supports further evaluation as a treatment for metabolic diseases.
Collapse
Affiliation(s)
| | | | | | | | - Tim Rolph
- Akero Therapeutics, South San Francisco, CA 94080, USA
| |
Collapse
|
9
|
Shepard CR. TLR9 in MAFLD and NASH: At the Intersection of Inflammation and Metabolism. Front Endocrinol (Lausanne) 2020; 11:613639. [PMID: 33584545 PMCID: PMC7880160 DOI: 10.3389/fendo.2020.613639] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022] Open
Abstract
Toll-Like Receptor 9 (TLR9) is an ancient receptor integral to the primordial functions of inflammation and metabolism. TLR9 functions to regulate homeostasis in a healthy system under acute stress. The literature supports that overactivation of TLR9 under the chronic stress of obesity is a critical driver of the pathogenesis of NASH and NASH-associated fibrosis. Research has focused on the core contributions of the parenchymal and non-parenchymal cells in the liver, adipose, and gut compartments. TLR9 is activated by endogenous circulating mitochondrial DNA (mtDNA). Chronically elevated circulating levels of mtDNA, caused by the stress of overnutrition, are observed in obesity, metabolic dysfunction-associated fatty liver disease (MAFLD), and NASH. Clinical evidence is supportive of TLR9 overactivation as a driver of disease. The role of TLR9 in metabolism and energy regulation may have an underappreciated contribution in the pathogenesis of NASH. Antagonism of TLR9 in NASH and NASH-associated fibrosis could be an effective therapeutic strategy to target both the inflammatory and metabolic components of such a complex disease.
Collapse
|
10
|
Tillman EJ, Rolph T. FGF21: An Emerging Therapeutic Target for Non-Alcoholic Steatohepatitis and Related Metabolic Diseases. Front Endocrinol (Lausanne) 2020; 11:601290. [PMID: 33381084 PMCID: PMC7767990 DOI: 10.3389/fendo.2020.601290] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/12/2020] [Indexed: 12/13/2022] Open
Abstract
The rising global prevalence of obesity, metabolic syndrome, and type 2 diabetes has driven a sharp increase in non-alcoholic fatty liver disease (NAFLD), characterized by excessive fat accumulation in the liver. Approximately one-sixth of the NAFLD population progresses to non-alcoholic steatohepatitis (NASH) with liver inflammation, hepatocyte injury and cell death, liver fibrosis and cirrhosis. NASH is one of the leading causes of liver transplant, and an increasingly common cause of hepatocellular carcinoma (HCC), underscoring the need for intervention. The complex pathophysiology of NASH, and a predicted prevalence of 3-5% of the adult population worldwide, has prompted drug development programs aimed at multiple targets across all stages of the disease. Currently, there are no approved therapeutics. Liver-related morbidity and mortality are highest in more advanced fibrotic NASH, which has led to an early focus on anti-fibrotic approaches to prevent progression to cirrhosis and HCC. Due to limited clinical efficacy, anti-fibrotic approaches have been superseded by mechanisms that target the underlying driver of NASH pathogenesis, namely steatosis, which drives hepatocyte injury and downstream inflammation and fibrosis. Among this wave of therapeutic mechanisms targeting the underlying pathogenesis of NASH, the hormone fibroblast growth factor 21 (FGF21) holds considerable promise; it decreases liver fat and hepatocyte injury while suppressing inflammation and fibrosis across multiple preclinical studies. In this review, we summarize preclinical and clinical data from studies with FGF21 and FGF21 analogs, in the context of the pathophysiology of NASH and underlying metabolic diseases.
Collapse
|
11
|
Sanyal A, Charles ED, Neuschwander-Tetri BA, Loomba R, Harrison SA, Abdelmalek MF, Lawitz EJ, Halegoua-DeMarzio D, Kundu S, Noviello S, Luo Y, Christian R. Pegbelfermin (BMS-986036), a PEGylated fibroblast growth factor 21 analogue, in patients with non-alcoholic steatohepatitis: a randomised, double-blind, placebo-controlled, phase 2a trial. Lancet 2019; 392:2705-2717. [PMID: 30554783 DOI: 10.1016/s0140-6736(18)31785-9] [Citation(s) in RCA: 363] [Impact Index Per Article: 72.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 07/05/2018] [Accepted: 07/27/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Pegbelfermin (BMS-986036), a PEGylated human fibroblast growth factor 21 (FGF21) analogue, has previously been shown to improve markers of metabolism and liver fibrosis in obese patients with type 2 diabetes. In this phase 2a study, we aimed to evaluate the safety and efficacy of pegbelfermin in patients with non-alcoholic steatohepatitis. METHODS In this multicentre, randomised, double-blind, placebo-controlled, parallel-group, phase 2a study, we recruited adults (aged 21-75 years) with a body-mass index of at least 25 kg/m2, biopsy-confirmed non-alcoholic steatohepatitis (fibrosis stage 1-3), and a hepatic fat fraction of at least 10% when assessed by magnetic resonance imaging-proton density fat fraction. These patients were enrolled at 17 medical centres in the USA. Eligible patients were stratified by type 2 diabetes status and they were randomly assigned (1:1:1) by a computer-based system to receive subcutaneous injections of placebo once a day, 10 mg pegbelfermin once a day, or 20 mg pegbelfermin once a week, all for 16 weeks. Participants, the study team administering treatment, and investigators analysing outcomes (who were independent of the study team and had no further involvement) were masked to treatment groups. The primary outcomes were safety and the absolute change in hepatic fat fraction after 16 weeks of treatment. All patients who were randomly assigned to groups and received the study drug or placebo were included in the primary analyses. This trial was registered with ClinicalTrials.gov, number NCT02413372. FINDINGS Between May 12, 2015, and Aug 4, 2016, 184 overweight or obese patients with non-alcoholic steatohepatitis were screened for study inclusion. Of these, 95 (52%) patients were excluded because they no longer met study criteria and 80 (43%) patients entered the placebo lead-in phase. After further exclusions, 75 (94%) patients were randomly assigned to groups, received at least one dose of treatment (25 patients to receive 10 mg pegbelfermin once a day; 24 patients to receive 20 mg pegbelfermin once a week, and 26 patients to receive placebo), and were included in the primary analysis. A prespecified interim analysis at week 8 showed a greater than expected change in the primary outcome and supported early closing of patient enrolment, since this analysis indicated that the full planned sample size was not needed. We observed a significant decrease in absolute hepatic fat fraction in the group receiving 10 mg pegbelfermin daily (-6·8% vs -1·3%; p=0·0004) and in the group receiving 20 mg pegbelfermin weekly (-5·2% vs -1·3%; p=0·008) compared with the placebo group. Most adverse events were mild; the most common events were diarrhoea in eight (16%) of 49 patients treated with pegbelfermin and two (8%) of 26 patients treated with placebo and nausea in seven (14%) patients treated with pegbelfermin and two (8%) patients treated with placebo. There were no deaths, discontinuations due to adverse events, or treatment-related serious adverse events. INTERPRETATION Treatment with subcutaneously administered pegbelfermin for 16 weeks was generally well tolerated and significantly reduced hepatic fat fraction in patients with non-alcoholic steatohepatitis. Further study of pegbelfermin is warranted in patients with non-alcoholic steatohepatitis. Additional studies that use liver biopsies would allow for the assessment of pegbelfermin's effects on liver histology. Moreover, further studies should allow assessments of the safety and effectiveness of pegbelfermin in a larger number of patients. FUNDING Bristol-Myers Squibb.
Collapse
Affiliation(s)
- Arun Sanyal
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | | | | | - Rohit Loomba
- Division of Gastroenterology, University of California, San Diego, San Diego, CA, USA
| | | | | | - Eric J Lawitz
- Texas Liver Institute, University of Texas Health San Antonio, San Antonio, TX, USA
| | | | | | | | - Yi Luo
- Bristol-Myers Squibb, Princeton, NJ, USA
| | | |
Collapse
|
12
|
Vallée A, Lecarpentier Y. TGF-β in fibrosis by acting as a conductor for contractile properties of myofibroblasts. Cell Biosci 2019; 9:98. [PMID: 31827764 PMCID: PMC6902440 DOI: 10.1186/s13578-019-0362-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/30/2019] [Indexed: 12/21/2022] Open
Abstract
Myofibroblasts are non-muscle contractile cells that play a key physiologically role in organs such as the stem villi of the human placenta during physiological pregnancy. They are able to contract and relax in response to changes in the volume of the intervillous chamber. Myofibroblasts have also been observed in several diseases and are involved in wound healing and the fibrotic processes affecting several organs, such as the liver, lungs, kidneys and heart. During the fibrotic process, tissue retraction rather than contraction is correlated with collagen synthesis in the extracellular matrix, leading to irreversible fibrosis and, finally, apoptosis of myofibroblasts. The molecular motor of myofibroblasts is the non-muscle type IIA and B myosin (NMMIIA and NMMIIB). Fibroblast differentiation into myofibroblasts is largely governed by the transforming growth factor-β1 (TGF-β1). This system controls the canonical WNT/β-catenin pathway in a positive manner, and PPARγ in a negative manner. The WNT/β-catenin pathway promotes fibrosis, while PPARγ prevents it. This review focuses on the contractile properties of myofibroblasts and the conductor, TGF-β1, which together control the opposing interplay between PPARγ and the canonical WNT/β-catenin pathway.
Collapse
Affiliation(s)
- Alexandre Vallée
- 1Délégation à la Recherche Clinique (DRCI), Hôpital Foch, Suresnes, France.,DACTIM-MIS, Laboratoire de Mathématiques et Applications (LMA), CNRS, UMR 7348, Université de Poitiers, CHU de Poitiers, Poitiers, France
| | - Yves Lecarpentier
- Centre de Recherche Clinique, Grand Hôpital de l'Est Francilien (GHEF), Meaux, France
| |
Collapse
|
13
|
Akt1 and Akt2 Isoforms Play Distinct Roles in Regulating the Development of Inflammation and Fibrosis Associated with Alcoholic Liver Disease. Cells 2019; 8:cells8111337. [PMID: 31671832 PMCID: PMC6912497 DOI: 10.3390/cells8111337] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/11/2019] [Accepted: 10/21/2019] [Indexed: 12/13/2022] Open
Abstract
Akt kinase isoforms (Akt1, Akt2, and Akt3) have generally been thought to play overlapping roles in phosphoinositide 3-kinase (PI3K)-mediated-signaling. However, recent studies have suggested that they display isoform-specific roles in muscle and fat. To determine whether such isoform-specificity is observed with respect to alcoholic liver disease (ALD) progression, we examined the role of Akt1, Akt2, and Akt3 in hepatic inflammation, and pro-fibrogenic proliferation and migration using Kupffer cells, hepatic stellate cells (HSC), and hepatocytes in an ethanol and lipopolysaccharide (LPS)-induced two-hit model in vitro and in vivo. We determined that siRNA-directed silencing of Akt2, but not Akt1, significantly suppressed cell inflammatory markers in HSC and Kupffer cells. Although both Akt1 and Akt2 inhibited cell proliferation in HSC, only Akt2 inhibited cell migration. Both Akt1 and Akt2, but not Akt3, inhibited fibrogenesis in hepatocytes and HSC. In addition, our in vivo results show that administration of chronic ethanol, binge ethanol and LPS (EBL) in wild-type C57BL/6 mice activated all three Akt isoforms with concomitant increases in activated forms of phosphoinositide dependent kinase-1 (PDK1), mammalian target-of-rapamycin complex 2 (mTORC2), and PI3K, resulting in upregulation in expression of inflammatory, proliferative, and fibrogenic genes. Moreover, pharmacological blocking of Akt2, but not Akt1, inhibited EBL-induced inflammation while blocking of both Akt1 and Akt2 inhibited pro-fibrogenic marker expression and progression of fibrosis. Our findings indicate that Akt isoforms play unique roles in inflammation, cell proliferation, migration, and fibrogenesis during EBL-induced liver injury. Thus, close attention must be paid when targeting all Akt isoforms as a therapeutic intervention.
Collapse
|
14
|
Liu X, Long X, Gao Y, Liu W, Hayashi T, Mizuno K, Hattori S, Fujisaki H, Ogura T, Onodera S, Wang DO, Ikejima T. Type I collagen inhibits adipogenic differentiation via YAP activation in vitro. J Cell Physiol 2019; 235:1821-1837. [PMID: 31432516 DOI: 10.1002/jcp.29100] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/27/2019] [Indexed: 12/18/2022]
Abstract
Extracellular matrix (ECM) has a marked influence on adipose tissue development. Adipose tissue formation is initiated with proliferation of preadipocytes and migration before undergoing further differentiation into mature adipocytes. Previous studies showed that collagen I (col I) provides a good substratum for 3T3-L1 preadipocytes to grow and migrate. However, it remains unclear whether and how col I regulates adipogenic differentiation of preadipocytes. This study reports that lipid accumulation, representing in vitro adipogenesis of the 3T3-L1 preadipocytes or the mouse primary adipocyte precursor cells derived from subcutaneous adipose tissue in the inguinal region is inhibited by the culture on col I, owing to downregulation of adipogenic factors. Previous study shows that col I enhances 3T3-L1 cell migration via stimulating the nuclear translocation of yes-associated protein (YAP). In this study, we report that downregulation of YAP is associated with in vitro adipogenesis of preadipocytes as well as with in vivo adipose tissue of high-fat diet fed mice. Increased expression of YAP in the cells cultured on col I-coated dishes is correlated with repression of adipogenic differentiation processes. The inactivation of YAP using YAP inhibitor, verteporfin, or YAP small-interfering RNA enhanced adipogenic differentiation and reversed the inhibitory effect of col I. Activation of YAP either by the transfection of YAP plasmid or the silence of large tumor suppressor 1 (LATS1), an inhibitory kinase of YAP, inhibited adipogenic differentiation. The results indicate that col I inhibits adipogenic differentiation via YAP activation in vitro.
Collapse
Affiliation(s)
- Xiaoling Liu
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, China
| | - Xinyu Long
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, China
| | - Yanfang Gao
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, China
| | - Weiwei Liu
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, China
| | - Toshihiko Hayashi
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, China.,Department of Chemistry and Life Science, School of Advan ced Engineering, Kogakuin University, Nakanomachi, Hachioji, Tokyo, Japan
| | | | | | | | | | - Satoshi Onodera
- Medical Research Institute of Curing Mibyo, Narusedai, Machida, Tokyo, Japan
| | - Dan Ohtan Wang
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, China
| | - Takashi Ikejima
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, China.,Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research & Development, Shenyang Pharmaceutical University, Shenyang, Liaoning, China
| |
Collapse
|
15
|
Abstract
PURPOSE OF REVIEW Hepatitis C virus (HCV) infection has been the leading cause of cirrhosis in the United States now for the last several decades. With the introduction of highly effective direct acting antiviral (DAA) drugs, cure rates are now almost 100%. With this explosion of effective therapy, it is possible that many patients with HCV may have reversion in fibrosis. The purpose of this review is, therefore, to report on recent findings in this field. RECENT FINDINGS Older data that examined the effect of interferon-based HCV therapy indicate that fibrosis reverses after HCV eradication. More recent work in the DAA era similarly indicates that fibrosis is reversible. A caveat is that DAA therapy causes rapid viral clearance, and appears to lead to rapid reductions in inflammation. Some tools (such as transient elastography), which may also reflect the inflammatory response, and thus may 'overestimate' of fibrosis reversal. However, emerging data suggesting improved outcomes in patients with cirrhosis after HCV clearance support the concept that even cirrhosis reverses in some patients. SUMMARY Fibrosis (and cirrhosis) reversion, to some extent, occurs after HCV clearance. This topic is vitally important and information continues to emerge; more data on this subject are expected and needed.
Collapse
|
16
|
Abstract
Adiponectin is one of the most widely studied adipokines to date. First described in the mid-1990's, studying its regulation, biogenesis and physiological effects has proven to be extremely insightful and improved our understanding of the mechanisms that ensure systemic metabolic homeostasis. Here, we provide a brief overview of the current state of the field with respect to adiponectin, its history, sites and mechanisms of action, and the critical questions that will need to be addressed in the future.
Collapse
Affiliation(s)
- Leon G Straub
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
17
|
Charles ED, Neuschwander‐Tetri BA, Pablo Frias J, Kundu S, Luo Y, Tirucherai GS, Christian R. Pegbelfermin (BMS-986036), PEGylated FGF21, in Patients with Obesity and Type 2 Diabetes: Results from a Randomized Phase 2 Study. Obesity (Silver Spring) 2019; 27:41-49. [PMID: 30520566 PMCID: PMC6587787 DOI: 10.1002/oby.22344] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/30/2018] [Accepted: 08/30/2018] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Obesity and type 2 diabetes mellitus (T2DM) are risk factors for nonalcoholic fatty liver disease, including nonalcoholic steatohepatitis. This study assessed pegbelfermin (BMS-986036), recombinant PEGylated human fibroblast growth factor 21 (FGF21), in patients with obesity and T2DM predisposed to fatty liver. METHODS In this randomized, double-blind, placebo-controlled study, patients with T2DM and BMI of 30 to 50 kg/m2 received subcutaneous pegbelfermin (1, 5, or 20 mg daily or 20 mg weekly; n = 96) or placebo (n = 24) for 12 weeks. Primary end points were safety, tolerability, and change in HbA1c. Additional end points included insulin sensitivity, lipids, adiponectin, and disease progression biomarkers. RESULTS There were no significant effects of pegbelfermin versus placebo on HbA1c. Pegbelfermin 20 mg/d significantly improved high-density lipoprotein cholesterol (P = 0.015) and triglycerides (P = 0.037). All pegbelfermin regimens significantly increased adiponectin levels; 20-mg daily and weekly regimens decreased serum PRO-C3. Most adverse events were mild; the most frequent adverse events were injection-site bruising and diarrhea. CONCLUSIONS Twelve-week pegbelfermin treatment did not impact HbA1c concentrations, but QW and higher daily doses were associated with improved metabolic parameters and fibrosis biomarkers in patients with obesity and T2DM predisposed to fatty liver. These results support evaluation of pegbelfermin in patients with obesity-related metabolic diseases (e.g., nonalcoholic steatohepatitis).
Collapse
Affiliation(s)
| | - Brent A. Neuschwander‐Tetri
- Department of Internal Medicine, Division of Gastroenterology and HepatologySaint Louis University, School of MedicineSt. LouisMissouriUSA
| | | | | | - Yi Luo
- Bristol‐Myers SquibbPrincetonNew JerseyUSA
| | | | | |
Collapse
|
18
|
|
19
|
Gamberi T, Magherini F, Modesti A, Fiaschi T. Adiponectin Signaling Pathways in Liver Diseases. Biomedicines 2018; 6:biomedicines6020052. [PMID: 29735928 PMCID: PMC6027295 DOI: 10.3390/biomedicines6020052] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/26/2018] [Accepted: 05/02/2018] [Indexed: 02/07/2023] Open
Abstract
In the liver, adiponectin regulates both glucose and lipid metabolism and exerts an insulin-sensitizing effect. The binding of adiponectin with its specific receptors induces the activation of a proper signaling cascade that becomes altered in liver pathologies. This review describes the different signaling pathways in healthy and diseased hepatocytes, also highlighting the beneficial role of adiponectin in autophagy activation and hepatic regeneration.
Collapse
Affiliation(s)
- Tania Gamberi
- Dipartimento di Scienze Biomediche, Sperimentali e Cliniche "Mario Serio", Università degli Studi di Firenze, Viale Morgagni 50, 50134 Firenze, Italy.
| | - Francesca Magherini
- Dipartimento di Scienze Biomediche, Sperimentali e Cliniche "Mario Serio", Università degli Studi di Firenze, Viale Morgagni 50, 50134 Firenze, Italy.
| | - Alessandra Modesti
- Dipartimento di Scienze Biomediche, Sperimentali e Cliniche "Mario Serio", Università degli Studi di Firenze, Viale Morgagni 50, 50134 Firenze, Italy.
| | - Tania Fiaschi
- Dipartimento di Scienze Biomediche, Sperimentali e Cliniche "Mario Serio", Università degli Studi di Firenze, Viale Morgagni 50, 50134 Firenze, Italy.
| |
Collapse
|
20
|
Hepatic stellate cells as key target in liver fibrosis. Adv Drug Deliv Rev 2017; 121:27-42. [PMID: 28506744 DOI: 10.1016/j.addr.2017.05.007] [Citation(s) in RCA: 875] [Impact Index Per Article: 125.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/21/2017] [Accepted: 05/09/2017] [Indexed: 02/06/2023]
Abstract
Progressive liver fibrosis, induced by chronic viral and metabolic disorders, leads to more than one million deaths annually via development of cirrhosis, although no antifibrotic therapy has been approved to date. Transdifferentiation (or "activation") of hepatic stellate cells is the major cellular source of matrix protein-secreting myofibroblasts, the major driver of liver fibrogenesis. Paracrine signals from injured epithelial cells, fibrotic tissue microenvironment, immune and systemic metabolic dysregulation, enteric dysbiosis, and hepatitis viral products can directly or indirectly induce stellate cell activation. Dysregulated intracellular signaling, epigenetic changes, and cellular stress response represent candidate targets to deactivate stellate cells by inducing reversion to inactivated state, cellular senescence, apoptosis, and/or clearance by immune cells. Cell type- and target-specific pharmacological intervention to therapeutically induce the deactivation will enable more effective and less toxic precision antifibrotic therapies.
Collapse
|
21
|
Lecarpentier Y, Schussler O, Claes V, Vallée A. The Myofibroblast: TGFβ-1, A Conductor which Plays a Key Role in Fibrosis by Regulating the Balance between PPARγ and the Canonical WNT Pathway. NUCLEAR RECEPTOR RESEARCH 2017. [DOI: 10.11131/2017/101299] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Yves Lecarpentier
- Centre de Recherche Clinique, Grand Hôpital de l’Est Francilien (GHEP), Meaux, France
| | - Olivier Schussler
- Department of Cardiovascular Surgery, Cardiovascular Research Laboratory, HUG/CMU, Geneva, Switzerland
| | - Victor Claes
- Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Alexandre Vallée
- Experimental and Clinical Neurosciences Laboratory, INSERM U1084, University of Poitiers, Poitiers, France
| |
Collapse
|
22
|
Vallée A, Lecarpentier Y, Guillevin R, Vallée JN. Interactions between TGF-β1, canonical WNT/β-catenin pathway and PPAR γ in radiation-induced fibrosis. Oncotarget 2017; 8:90579-90604. [PMID: 29163854 PMCID: PMC5685775 DOI: 10.18632/oncotarget.21234] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 08/17/2017] [Indexed: 12/16/2022] Open
Abstract
Radiation therapy induces DNA damage and inflammation leading to fibrosis. Fibrosis can occur 4 to 12 months after radiation therapy. This process worsens with time and years. Radiation-induced fibrosis is characterized by fibroblasts proliferation, myofibroblast differentiation, and synthesis of collagen, proteoglycans and extracellular matrix. Myofibroblasts are non-muscle cells that can contract and relax. Myofibroblasts evolve towards irreversible retraction during fibrosis process. In this review, we discussed the interplays between transforming growth factor-β1 (TGF-β1), canonical WNT/β-catenin pathway and peroxisome proliferator-activated receptor gamma (PPAR γ) in regulating the molecular mechanisms underlying the radiation-induced fibrosis, and the potential role of PPAR γ agonists. Overexpression of TGF-β and canonical WNT/β-catenin pathway stimulate fibroblasts accumulation and myofibroblast differentiation whereas PPAR γ expression decreases due to the opposite interplay of canonical WNT/β-catenin pathway. Both TGF-β1 and canonical WNT/β-catenin pathway stimulate each other through the Smad pathway and non-Smad pathways such as phosphatidylinositol 3-kinase/serine/threonine kinase (PI3K/Akt) signaling. WNT/β-catenin pathway and PPAR γ interact in an opposite manner. PPAR γ agonists decrease β-catenin levels through activation of inhibitors of the WNT pathway such as Smad7, glycogen synthase kinase-3 (GSK-3 β) and dickkopf-related protein 1 (DKK1). PPAR γ agonists also stimulate phosphatase and tensin homolog (PTEN) expression, which decreases both TGF-β1 and PI3K/Akt pathways. PPAR γ agonists by activating Smad7 decrease Smads pathway and then TGF-β signaling leading to decrease radiation-induced fibrosis. TGF-β1 and canonical WNT/β-catenin pathway promote radiation-induced fibrosis whereas PPAR γ agonists can prevent radiation-induced fibrosis.
Collapse
Affiliation(s)
- Alexandre Vallée
- Experimental and Clinical Neurosciences Laboratory, INSERM U1084, University of Poitiers, Poitiers, France.,Laboratory of Mathematics and Applications (LMA), UMR CNRS 7348, University of Poitiers, Poitiers, France
| | - Yves Lecarpentier
- Centre de Recherche Clinique, Grand Hôpital de l'Est Francilien (GHEF), Meaux, France
| | - Rémy Guillevin
- DACTIM, UMR CNRS 7348, University of Poitiers et CHU de Poitiers, Poitiers, France
| | - Jean-Noël Vallée
- Laboratory of Mathematics and Applications (LMA), UMR CNRS 7348, University of Poitiers, Poitiers, France.,CHU Amiens Picardie, University of Picardie Jules Verne (UPJV), Amiens, France
| |
Collapse
|
23
|
Abstract
Hepatic fibrosis is a dynamic process characterized by the net accumulation of extracellular matrix resulting from chronic liver injury of any aetiology, including viral infection, alcoholic liver disease and NASH. Activation of hepatic stellate cells (HSCs) - transdifferentiation of quiescent, vitamin-A-storing cells into proliferative, fibrogenic myofibroblasts - is now well established as a central driver of fibrosis in experimental and human liver injury. Yet, the continued discovery of novel pathways and mediators, including autophagy, endoplasmic reticulum stress, oxidative stress, retinol and cholesterol metabolism, epigenetics and receptor-mediated signals, reveals the complexity of HSC activation. Extracellular signals from resident and inflammatory cells including macrophages, hepatocytes, liver sinusoidal endothelial cells, natural killer cells, natural killer T cells, platelets and B cells further modulate HSC activation. Finally, pathways of HSC clearance have been greatly clarified, and include apoptosis, senescence and reversion to an inactivated state. Collectively, these findings reinforce the remarkable complexity and plasticity of HSC activation, and underscore the value of clarifying its regulation in hopes of advancing the development of novel diagnostics and therapies for liver disease.
Collapse
Affiliation(s)
- Takuma Tsuchida
- Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1123, New York, New York 10029, USA.,Research Division, Mitsubishi Tanabe Pharma Corporation, 2-2-50, Kawagishi, Toda-shi, Saitama 335-8505, Japan
| | - Scott L Friedman
- Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1123, New York, New York 10029, USA
| |
Collapse
|
24
|
Sharma AX, Holland WL. Adiponectin and its Hydrolase-Activated Receptors. JOURNAL OF NATURE AND SCIENCE 2017; 3:e396. [PMID: 28758149 PMCID: PMC5531184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The relevance of adiponectin to insulin sensitivity has been elucidated over the last two decades. As a promoter of ceramide degradation, it works through its cognate receptors, AdipoR1 and AdipoR2, to alter bioactive sphingolipid species. Adiponectin diminishes the accumulation of ceramide, a lipid metabolite which can play a causal role in obesity-induced insulin resistance. Concurrently, adiponectin stimulates the production of sphingosine-1-phosphate (S1P), a cyto-protective molecule that accentuates adiponectin's positive metabolic effects. This review focuses on recent work that solidifies knowledge of the adiponectin signaling pathway, gives new insight into some notable characteristics of adiponectin's receptors, and most importantly, affirms adiponectin receptor agonism as a viable therapeutic tool to combat elevated ceramide levels and improve insulin sensitivity in obese patients with type II diabetes.
Collapse
Affiliation(s)
| | - William L. Holland
- Corresponding Author: William L. Holland. Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390-8549, USA. Tel: 214-648-2566; Fax: 214-648-8720.
| |
Collapse
|
25
|
Abstract
Obesity is a worldwide epidemic that predisposes individuals to cardiometabolic complications, such as type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD), which are all related to inappropriate ectopic lipid deposition. Identification of the pathogenic molecular mechanisms and effective therapeutic approaches are highly needed. The peroxisome proliferator-activated receptors (PPARs) modulate several biological processes that are perturbed in obesity, including inflammation, lipid and glucose metabolism and overall energy homeostasis. Here, we review how PPARs regulate the functions of adipose tissues, such as adipogenesis, lipid storage and adaptive thermogenesis, under healthy and pathological conditions. We also discuss the clinical use and mechanism of PPAR agonists in the treatment of obesity comorbidities such as dyslipidaemia, T2DM and NAFLD. First generation PPAR agonists, primarily those acting on PPARγ, are associated with adverse effects that outweigh their clinical benefits, which led to the discontinuation of their development. An improved understanding of the physiological roles of PPARs might, therefore, enable the development of safe, new PPAR agonists with improved therapeutic potential.
Collapse
Affiliation(s)
- Barbara Gross
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Michal Pawlak
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, 02-109 Warsaw, Poland
| | - Philippe Lefebvre
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Bart Staels
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| |
Collapse
|
26
|
Panera N, Della Corte C, Crudele A, Stronati L, Nobili V, Alisi A. Recent advances in understanding the role of adipocytokines during non-alcoholic fatty liver disease pathogenesis and their link with hepatokines. Expert Rev Gastroenterol Hepatol 2016; 10:393-403. [PMID: 26654761 DOI: 10.1586/17474124.2016.1110485] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is currently considered the main cause of chronic liver disease worldwide. Mechanisms leading to the development and progression of this disease are topics of great interest for researchers and clinicians. The current multi-hit hypothesis has thrown the crosstalk between liver and adipose tissue into sharp focus. It is well known that adipose tissue produces circulating factors, known as adipocytokines, which exert several effects on liver cells, promoting the onset of NAFLD and its progression to non-alcoholic steatohepatitis in obese subjects. In a similar way, hepatocytes may also respond to obesogenic stimuli by producing and releasing hepatokines into the circulation. Here, the authors provide an overview of recent advances in our understanding of the role of the most relevant adipocytokines and hepatokines in NAFLD pathogenesis, highlighting their possible molecular and functional interactions.
Collapse
Affiliation(s)
- Nadia Panera
- a Liver Research Unit , 'Bambino Gesù' Children's Hospital, IRCCS , Rome , Italy
| | - Claudia Della Corte
- b Hepato-Metabolic Disease Unit , 'Bambino Gesù' Children's Hospital, IRCCS , Rome , Italy
| | - Annalisa Crudele
- a Liver Research Unit , 'Bambino Gesù' Children's Hospital, IRCCS , Rome , Italy
| | - Laura Stronati
- c Department of Radiobiology and Human Health , ENEA , Rome , Italy
| | - Valerio Nobili
- b Hepato-Metabolic Disease Unit , 'Bambino Gesù' Children's Hospital, IRCCS , Rome , Italy
| | - Anna Alisi
- a Liver Research Unit , 'Bambino Gesù' Children's Hospital, IRCCS , Rome , Italy
| |
Collapse
|
27
|
Preclinical Models for Investigation of Herbal Medicines in Liver Diseases: Update and Perspective. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2016; 2016:4750163. [PMID: 26941826 PMCID: PMC4749812 DOI: 10.1155/2016/4750163] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/23/2015] [Accepted: 12/30/2015] [Indexed: 02/07/2023]
Abstract
Liver disease results from a dynamic pathological process associated with cellular and genetic alterations, which may progress stepwise to liver dysfunction. Commonly, liver disease begins with hepatocyte injury, followed by persistent episodes of cellular regeneration, inflammation, and hepatocyte death that may ultimately lead to nonreversible liver failure. For centuries, herbal remedies have been used for a variety of liver diseases and recent studies have identified the active compounds that may interact with liver disease-associated targets. Further study on the herbal remedies may lead to the formulation of next generation medicines with hepatoprotective, antifibrotic, and anticancer properties. Still, the pharmacological actions of vast majority of herbal remedies remain unknown; thus, extensive preclinical studies are important. In this review, we summarize progress made over the last five years of the most commonly used preclinical models of liver diseases that are used to screen for curative herbal medicines for nonalcoholic fatty liver disease, liver fibrosis/cirrhosis, and liver. We also summarize the proposed mechanisms associated with the observed liver-protective, antifibrotic, and anticancer actions of several promising herbal medicines and discuss the challenges faced in this research field.
Collapse
|
28
|
Santamarina AB, Oliveira JL, Silva FP, Carnier J, Mennitti LV, Santana AA, de Souza GHI, Ribeiro EB, Oller do Nascimento CM, Lira FS, Oyama LM. Green Tea Extract Rich in Epigallocatechin-3-Gallate Prevents Fatty Liver by AMPK Activation via LKB1 in Mice Fed a High-Fat Diet. PLoS One 2015; 10:e0141227. [PMID: 26536464 PMCID: PMC4633218 DOI: 10.1371/journal.pone.0141227] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 10/05/2015] [Indexed: 01/19/2023] Open
Abstract
Supplementation with epigallocatechin-3-gallate has been determined to aid in the prevention of obesity. Decaffeinated green tea extract appears to restore a normal hepatic metabolic profile and attenuate high-fat diet (HFD)-induced effects, thereby preventing non-alcoholic fatty liver disease in mice. Mice were maintained on either a control diet (CD) or HFD for 16 weeks and supplemented with either water or green tea extract (50 mg/kg/day). The body mass increase, serum adiponectin level, and lipid profile were measured over the course of the treatment. Furthermore, the AMPK pathway protein expression in the liver was measured. From the fourth week, the weight gain in the CD + green tea extract (CE) group was lower than that in the CD + water (CW) group. From the eighth week, the weight gain in the HFD + water (HFW) group was found to be higher than that in the CW group. Moreover, the weight gain in the HFD + green tea extract (HFE) group was found to be lower than that in the HFW group. Carcass lipid content was found to be higher in the HFW group than that in the CW and HFE groups. Serum analysis showed reduced non-esterified fatty acid level in the CE and HFE groups as compared with their corresponding placebo groups. Increased adiponectin level was observed in the same groups. Increased VLDL-TG secretion was observed in the HFW group as compared with the CW and HFE groups. Increased protein expression of AdipoR2, SIRT1, pLKB1, and pAMPK was observed in the HFE group, which explained the reduced expression of ACC, FAS, SREBP-1, and ChREBP in this group. These results indicate that the effects of decaffeinated green tea extract may be related to the activation of AMPK via LKB1 in the liver of HFD-fed mice.
Collapse
Affiliation(s)
| | - Juliana L. Oliveira
- Departamento de Fisiologia—Universidade Federal de São Paulo, São Paulo, Brazil
| | - Fernanda P. Silva
- Departamento de Fisiologia—Universidade Federal de São Paulo, São Paulo, Brazil
| | - June Carnier
- Departamento de Fisiologia—Universidade Federal de São Paulo, São Paulo, Brazil
| | - Laís V. Mennitti
- Programa de Pós-Graduação Interdisciplinar em Ciências da Saúde—Universidade Federal de São Paulo, Santos, Brazil
| | - Aline A. Santana
- Departamento de Fisiologia—Universidade Federal de São Paulo, São Paulo, Brazil
| | | | - Eliane B. Ribeiro
- Departamento de Fisiologia—Universidade Federal de São Paulo, São Paulo, Brazil
| | | | - Fábio S. Lira
- Exercise and Immunometabolism Research Group, Department of Physical Education, Universidade Estadual Paulista, UNESP, Presidente Prudente, SP, Brazil
| | - Lila M. Oyama
- Departamento de Fisiologia—Universidade Federal de São Paulo, São Paulo, Brazil
- * E-mail:
| |
Collapse
|
29
|
Adiponectin as an anti-fibrotic and anti-inflammatory adipokine in the liver. CURRENT PATHOBIOLOGY REPORTS 2015; 3:243-252. [PMID: 26858914 DOI: 10.1007/s40139-015-0094-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Hepatic fibrosis is a dynamic process resulting from excessive deposition of extracellular matrix in the liver; uncontrolled progression of fibrosis can eventually lead to liver cirrhosis and/or hepatocellular carcinoma. The fibrogenic process is complex and modulated by a number of both hepatic and extra-hepatic biological factors. Growing evidence indicates that adipokines, a group of cytokines produced by adipose tissue, impart dynamic functions in liver and are involved in modulation of hepatic fibrosis. In particular, two key adipokines, adiponectin and leptin, directly regulate many biological responses closely associated with development and progression of hepatic fibrosis. Leptin acts as a pro-fibrogenic cytokine, while adiponectin possesses anti-fibrogenic and anti-inflammatory properties. Adiponectin, acting via its cognate receptors, adiponectin receptors 1 and 2, potently suppresses fibrosis and inflammation in liver via multiple mechanisms. This review summarizes recent findings concerning the role of adiponectin in fibrogenic process in liver and addresses the underlying molecular mechanisms in modulation of fibrosis.
Collapse
|
30
|
Abbott MJ, Roth TM, Ho L, Wang L, O’Carroll D, Nissenson RA. Negative Skeletal Effects of Locally Produced Adiponectin. PLoS One 2015; 10:e0134290. [PMID: 26230337 PMCID: PMC4521914 DOI: 10.1371/journal.pone.0134290] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/07/2015] [Indexed: 01/15/2023] Open
Abstract
Epidemiological studies show that high circulating levels of adiponectin are associated with low bone mineral density. The effect of adiponectin on skeletal homeostasis, on osteoblasts in particular, remains controversial. We investigated this issue using mice with adipocyte-specific over-expression of adiponectin (AdTg). MicroCT and histomorphometric analysis revealed decreases (15%) in fractional bone volume in AdTg mice at the proximal tibia with no changes at the distal femur. Cortical bone thickness at mid-shafts of the tibia and at the tibiofibular junction was reduced (3–4%) in AdTg mice. Dynamic histomorphometry at the proximal tibia in AdTg mice revealed inhibition of bone formation. AdTg mice had increased numbers of adipocytes in close proximity to trabecular bone in the tibia, associated with increased adiponectin levels in tibial marrow. Treatment of BMSCs with adiponectin after initiation of osteoblastic differentiation resulted in reduced mineralized colony formation and reduced expression of mRNA of osteoblastic genes, osterix (70%), Runx2 (52%), alkaline phosphatase (72%), Col1 (74%), and osteocalcin (81%). Adiponectin treatment of differentiating osteoblasts increased expression of the osteoblast genes PPARγ (32%) and C/ebpα (55%) and increased adipocyte colony formation. These data suggest a model in which locally produced adiponectin plays a negative role in regulating skeletal homeostasis through inhibition of bone formation and by promoting an adipogenic phenotype.
Collapse
Affiliation(s)
- Marcia J. Abbott
- Endocrine Research Unit, VA Medical Center and Departments of Medicine and Physiology, University of California San Francisco, San Francisco, CA, United States of America
- Department of Health Sciences and Kinesiology, Crean College of Health and Behavioral Sciences, Chapman University, Orange, CA, United States of America
| | - Theresa M. Roth
- Endocrine Research Unit, VA Medical Center and Departments of Medicine and Physiology, University of California San Francisco, San Francisco, CA, United States of America
| | - Linh Ho
- Endocrine Research Unit, VA Medical Center and Departments of Medicine and Physiology, University of California San Francisco, San Francisco, CA, United States of America
| | - Liping Wang
- Endocrine Research Unit, VA Medical Center and Departments of Medicine and Physiology, University of California San Francisco, San Francisco, CA, United States of America
| | - Dylan O’Carroll
- Endocrine Research Unit, VA Medical Center and Departments of Medicine and Physiology, University of California San Francisco, San Francisco, CA, United States of America
| | - Robert A. Nissenson
- Endocrine Research Unit, VA Medical Center and Departments of Medicine and Physiology, University of California San Francisco, San Francisco, CA, United States of America
- * E-mail:
| |
Collapse
|
31
|
Kim TK, Park KS. Inhibitory effects of harpagoside on TNF-α-induced pro-inflammatory adipokine expression through PPAR-γ activation in 3T3-L1 adipocytes. Cytokine 2015; 76:368-374. [PMID: 26049170 DOI: 10.1016/j.cyto.2015.05.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 05/15/2015] [Accepted: 05/15/2015] [Indexed: 01/22/2023]
Abstract
Obesity is closely associated with increased production of pro-inflammatory adipokines, including interleukin (IL)-6, plasminogen activator inhibitor (PAI)-1, and adipose-tissue-derived monocyte chemoattractant protein (MCP)-1, which contribute to chronic and low-grade inflammation in adipose tissue. Harpagoside, a major iridoid glycoside present in devil's claw, has been reported to show anti-inflammatory activities by suppression of lipopolysaccharide (LPS)-induced production of inflammatory cytokines in murine macrophages. The present study is aimed to investigate the effects of harpagoside on both tumor necrosis factor (TNF)-α-induced inflammatory adipokine expression and its underlying signaling pathways in differentiated 3T3-L1 cells. Harpagoside significantly inhibited TNF-α-induced mRNA synthesis and protein production of the atherogenic adipokines including IL-6, PAI-1, and MCP-1. Further investigation of the molecular mechanism revealed that pretreatment with harpagoside activated peroxisome proliferator-activated receptor (PPAR)-γ. These findings suggest that the clinical application of medicinal plants which contain harpagoside may lead to a partial prevention of obesity-induced atherosclerosis by attenuating inflammatory responses.
Collapse
Affiliation(s)
- Tae Kon Kim
- Department of Medicinal Chemistry, College of Science and Engineering, Jungwon University, Republic of Korea
| | - Kyoung Sik Park
- Department of Biomedical Science, College of Science and Engineering, Cheongju University, Chungbuk, Republic of Korea.
| |
Collapse
|
32
|
The Role of PPAR Gamma in Systemic Sclerosis. PPAR Res 2015; 2015:124624. [PMID: 26064084 PMCID: PMC4438188 DOI: 10.1155/2015/124624] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 04/23/2015] [Accepted: 04/23/2015] [Indexed: 02/06/2023] Open
Abstract
Fibrosis is recognized as an important feature of many chronic diseases, such as systemic sclerosis (SSc), an autoimmune disease of unknown etiology, characterized by immune dysregulation and vascular injury, followed by progressive fibrosis affecting the skin and multiple internal organs. SSc has a poor prognosis because no therapy has been shown to reverse or arrest the progression of fibrosis, representing a major unmet medical need. Recently, antifibrotic effects of PPARγ ligands have been studied in vitro and in vivo and some theories have emerged leading to new insights. Aberrant PPARγ function seems to be implicated in pathological fibrosis in the skin and lungs. This antifibrotic effect is mainly related to the inhibition of TGF-β/Smad signal transduction but other pathways can be involved. This review focused on recent studies that identified PPARγ as an important novel pathway with critical roles in regulating connective tissue homeostasis, with emphasis on skin and lung fibrosis and its role on systemic sclerosis.
Collapse
|
33
|
Lin Z, Wu F, Lin S, Pan X, Jin L, Lu T, Shi L, Wang Y, Xu A, Li X. Adiponectin protects against acetaminophen-induced mitochondrial dysfunction and acute liver injury by promoting autophagy in mice. J Hepatol 2014; 61:825-31. [PMID: 24882054 DOI: 10.1016/j.jhep.2014.05.033] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/02/2014] [Accepted: 05/22/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Acetaminophen (APAP) overdose causes hepatic necrosis and acute liver injury by inducing mitochondrial dysfunction and damage. Although the biochemical pathways that mediate APAP-induced hepatotoxicity have been well studied, the body's defense mechanism to attenuate this disease remains elusive. This study investigated the roles of adiponectin, an adipocyte-secreted adipokine with pleiotropic protective effects against obesity-related metabolic dysfunction, in the pathogenesis of APAP-induced liver injury in mice. METHODS Adiponectin knockout (ADN KO) and C57 wild type mice were treated with an overdose of APAP, followed by histological and biochemical evaluation of liver injury and activation of autophagy. The mechanism of adiponectin in APAP-induced hepatocytic toxicity was also explored in primary cultured hepatocytes. RESULTS APAP overdose triggers a marked accumulation of adiponectin in injured liver tissues. ADN KO mice exhibit severely exacerbated mitochondrial dysfunction and damage, oxidative stress and necrosis and much higher mortality in response to APAP overdose, whereas these changes are reversed by a single injection of adiponectin. Mechanistically, adiponectin induces autophagosome formation by AMP-activated protein kinase (AMPK)-dependent activation of the Unc-51-like kinase 1, consequently leading to the removal of damaged mitochondria from hepatocytes. The protective effects of adiponectin against APAP-induced mitochondrial damage, oxidative stress and necrosis are abrogated by blockage of AMPK or pharmacological inhibition of autophagy. CONCLUSIONS Our findings suggest that the APAP-induced accumulation of adiponectin in liver tissues serves as an adaptive mechanism to ameliorate hepatotoxicity by promoting autophagy-mediated clearance of damaged mitochondria. Adiponectin agonists may represent a promising therapy for the drug-induced acute liver failure.
Collapse
Affiliation(s)
- Zhuofeng Lin
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China; State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China; Department of Medicine, The University of Hong Kong, Hong Kong, China; Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
| | - Fan Wu
- Engineering Research Center of Bioreactor and Pharmaceutical Development, Ministry of Education, Jilin Agricultural University, Changchun, China
| | - Shaoqiang Lin
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Xuebo Pan
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Leigang Jin
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Tingting Lu
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Lihua Shi
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Yu Wang
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China; Department of Medicine, The University of Hong Kong, Hong Kong, China; Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
| | - Aimin Xu
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China; State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China; Department of Medicine, The University of Hong Kong, Hong Kong, China; Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
| | - Xiaokun Li
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China; Engineering Research Center of Bioreactor and Pharmaceutical Development, Ministry of Education, Jilin Agricultural University, Changchun, China.
| |
Collapse
|
34
|
Silva T, Colombo G, Schiavon L. Adiponectin: A multitasking player in the field of liver diseases. DIABETES & METABOLISM 2014; 40:95-107. [DOI: 10.1016/j.diabet.2013.11.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 11/19/2013] [Accepted: 11/21/2013] [Indexed: 12/18/2022]
|
35
|
Tao C, Sifuentes A, Holland WL. Regulation of glucose and lipid homeostasis by adiponectin: effects on hepatocytes, pancreatic β cells and adipocytes. Best Pract Res Clin Endocrinol Metab 2014; 28:43-58. [PMID: 24417945 PMCID: PMC4455885 DOI: 10.1016/j.beem.2013.11.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Adiponectin has received considerable attention for its potential anti-diabetic actions. The adipokine exerts control of glucose and lipid homeostasis via critical effects within the liver, adipose, and pancreas. By stimulating adipogenesis, opposing inflammation, and influencing rates of lipid oxidation and lipolysis, adiponectin critically governs lipid spillover into non-adipose tissues. Ceramide, a cytotoxic and insulin desensitizing lipid metabolite formed when peripheral tissues are exposed to excessive lipid deposition, is potently opposed by adiponectin. Via adiponectin receptors, AdipoR1 and AdipoR2, adiponectin stimulates the deacylation of ceramide- yielding sphingosine for conversion to sphingosine 1-phosphate (S1P) by sphingosine kinase. The resulting conversion from ceramide to S1P promotes survival of functional beta cell mass, allowing for insulin production to meet insulin demands. Alleviation of ceramide burden on the liver allows for improvements in hepatic insulin action. Here, we summarize how adiponectin-induced changes in these tissues lead to improvements in glucose metabolism, highlighting the sphingolipid signaling mechanisms linking adiponectin to each action. ONE SENTENCE SUMMARY: We review the anti-diabetic actions of adiponectin.
Collapse
Affiliation(s)
- Caroline Tao
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - Angelica Sifuentes
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA
| | - William L Holland
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390-8549, USA.
| |
Collapse
|
36
|
Zhang K, Ai WB, Liu CB, Wu JF. Progress in understanding the relationship between Notch signaling pathway and hepatic stellate cell activation. Shijie Huaren Xiaohua Zazhi 2013; 21:3611-3616. [DOI: 10.11569/wcjd.v21.i33.3611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Multiple signaling pathways are involved in the pathogenesis of hepatic fibrosis, and the Notch signaling pathway plays an important role in promoting the activation of hepatic stellate cells (HSCs). This pathway participates in the activation of HSCs mainly by cooperating with transforming growth factor β (TGF-β)/BMP, nuclear factor-kappa B (NF-κB), and Wnt signaling pathways directly or indirectly. This review aims to explore the relationship between the Notch signaling pathway and the activation of HSCs as well as the cooperative actions between TGF-β/BMP, NF-κB, and Wnt and the Notch signaling pathway in the process of the activation of HSCs.
Collapse
|
37
|
Abstract
Fibrosis is increasingly appreciated as a major player in adipose tissue dysfunction. In rapidly expanding adipose tissue, pervasive hypoxia leads to an induction of HIF1α that in turn leads to a potent profibrotic transcriptional program. The pathophysiological impact of adipose tissue fibrosis is likely to play an equally important role on systemic metabolic alterations as fibrotic conditions play in the liver, heart, and kidney. Here, we discuss recent advances in our understanding of the genesis, modulation, and systemic impact of excessive extracellular matrix (ECM) accumulation in adipose tissue of both rodents and humans and the ensuing impact on metabolic dysfunction.
Collapse
Affiliation(s)
- Kai Sun
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | | | | | | |
Collapse
|
38
|
Translating an understanding of the pathogenesis of hepatic fibrosis to novel therapies. Clin Gastroenterol Hepatol 2013; 11:224-31.e1-5. [PMID: 23305825 PMCID: PMC4151461 DOI: 10.1016/j.cgh.2013.01.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The response to injury is one of wound healing and fibrogenesis, which ultimately leads to fibrosis. The fibrogenic response to injury is a generalized one across virtually all organ systems. In the liver, the injury response, typically occurring over a prolonged period of time, leads to cirrhosis (although it should be pointed out that not all patients with liver injury develop cirrhosis). The fact that many different diseases result in cirrhosis suggests a common pathogenesis. The study of hepatic fibrogenesis over the past 2 decades has been remarkably active, leading to a considerable understanding of this process. It clearly has been shown that the hepatic stellate cell is a central component in the fibrogenic process. It also has been recognized that other effector cells are important in the fibrogenic process, including resident fibroblasts, bone marrow-derived cells, fibrocytes, and even perhaps cells derived from epithelial cells (ie, through epithelial to mesenchymal transition). A key aspect of the biology of fibrogenesis is that the fibrogenic process is dynamic; thus, even advanced fibrosis (or cirrhosis) is reversible. Together, an understanding of the cellular basis for liver fibrogenesis, along with multiple aspects of the basic pathogenesis of fibrosis, have highlighted many exciting potential therapeutic opportunities. Thus, although the most effective antifibrotic therapy is simply treatment of the underlying disease, in situations in which this is not possible, specific antifibrotic therapy is likely not only to become feasible, but will soon become a reality. This review highlights the mechanisms underlying fibrogenesis that may be translated into future antifibrotic therapies and to review the current state of clinical development.
Collapse
|
39
|
Reyes-Gordillo K, Shah R, Arellanes-Robledo J, Rojkind M, Lakshman MR. Protective effects of thymosin β4 on carbon tetrachloride-induced acute hepatotoxicity in rats. Ann N Y Acad Sci 2013; 1269:61-8. [PMID: 23045971 DOI: 10.1111/j.1749-6632.2012.06728.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Thymosin β4 (Tβ4) plays a role in fibrosis, inflammation, and in the reparative process of injured cells and tissues. Here, we discuss our preliminary work on the protective effect of Tβ4 on carbon tetrachloride (CCl(4) )-induced acute hepatotoxicity. Our studies thus far indicate that Tβ4 can prevent necrosis, inflammatory infiltration, and upregulation of α1(and 2) collagen, α-SMA, PDGF-β receptor, and fibronectin mRNA expression; in addition, Tβ4 can prevent downregulation of PPARγ and upregulation of MECP2 mRNA levels in acute liver injury. Our initial work therefore indicates that Tβ4 can prevent the alteration of markers of hepatic stellate cell transdifferentiation, which suggests that Tβ4 could maintain the quiescent phenotypic state of hepatic stellate cells in the rat livers by restoring PPARγ and downregulating MeCP2 expression levels. More specifically, these preliminary studies suggest that Tβ4 might be an effective anti-inflammatory and antifibrotic drug for the treatment of liver fibrogenesis.
Collapse
Affiliation(s)
- Karina Reyes-Gordillo
- Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University Medical Center, Washington, DC, USA
| | | | | | | | | |
Collapse
|
40
|
Abstract
Maternal obesity increases offspring birth weight and susceptibility to obesity. Adiponectin is an adipocyte-secreted hormone with a prominent function in maintaining energy homeostasis. In contrast to adults, neonatal blood adiponectin levels are positively correlated with anthropometric parameters of adiposity. This study was designed to investigate the role of adiponectin in maternal obesityenhanced fetal fat deposition. By using high-fat diet-induced obese mouse models, our study showed that maternal obesity increased fetal fat tissue mass, with a significant elevation in fetal blood adiponectin. However, adiponectin gene knockout (Adipoq(-/-)) attenuated maternal obesity-induced high fetal fat tissue mass. We further studied the effects of fetal adiponectin on fetal fat deposition by using a cross breeding approach to create Adipoq(-/+) and Adipoq(-/-) offspring, whereas maternal adiponectin was null. Adipoq(-/+) offspring had more fat tissue mass at both birth and adulthood. Significantly high levels of lipogenic genes, such as sterol regulatory element-binding protein 1c and fatty acid synthase, were detected in the livers of Adipoq(-/+) fetuses. In addition, expression of genes for placental fatty acid transport was significantly increased in Adipoq(-/+) fetuses. Together, our study indicates that adiponectin enhances fetal fat deposition and plays an important role in maternal obesity-induced high birth weight.
Collapse
Affiliation(s)
- Liping Qiao
- Department of Pediatrics, University of California San Diego, La Jolla, California
| | - Hyung sun Yoo
- Department of Pediatrics, University of California San Diego, La Jolla, California
| | - Alysha Madon
- Department of Pediatrics, University of California San Diego, La Jolla, California
| | - Brice Kinney
- Department of Pediatrics, University of California San Diego, La Jolla, California
| | - William W. Hay
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado
| | - Jianhua Shao
- Department of Pediatrics, University of California San Diego, La Jolla, California
- Corresponding author: Jianhua Shao,
| |
Collapse
|
41
|
Fang F, Liu L, Yang Y, Tamaki Z, Wei J, Marangoni RG, Bhattacharyya S, Summer RS, Ye B, Varga J. The adipokine adiponectin has potent anti-fibrotic effects mediated via adenosine monophosphate-activated protein kinase: novel target for fibrosis therapy. Arthritis Res Ther 2012; 14:R229. [PMID: 23092446 PMCID: PMC3580540 DOI: 10.1186/ar4070] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 10/19/2012] [Indexed: 02/06/2023] Open
Abstract
Introduction Fibrosis in scleroderma is associated with collagen deposition and myofibroblast accumulation. Peroxisome proliferator activated receptor gamma (PPAR-γ), a master regulator of adipogenesis, inhibits profibrotic responses induced by transforming growth factor-ß (TGF-β), and its expression is impaired in scleroderma. The roles of adiponectin, a PPAR-γ regulated pleiotropic adipokine, in regulating the response of fibroblasts and in mediating the effects of PPAR-γ are unknown. Methods Regulation of fibrotic gene expression and TGF-ß signaling by adiponectin and adenosine monophosphate protein-activated (AMP) kinase agonists were examined in normal fibroblasts in monolayer cultures and in three-dimensional skin equivalents. AdipoR1/2 expression on skin fibroblasts was determined by real-time quantitative PCR. Results Adiponectin, an adipokine directly regulated by PPAR-γ, acts as a potent anti-fibrotic signal in normal and scleroderma fibroblasts that abrogates the stimulatory effects of diverse fibrotic stimuli and reduces elevated collagen gene expression in scleroderma fibroblasts. Adiponectin responses are mediated via AMP kinase, a fuel-sensing cellular enzyme that is necessary and sufficient for down-regulation of fibrotic genes by blocking canonical Smad signaling. Moreover, we demonstrate that endogenous adiponectin accounts, at least in part, for the anti-fibrotic effects exerted by ligands of PPAR-γ. Conclusions These findings reveal a novel link between cellular energy metabolism and extracellular matrix homeostasis converging on AMP kinase. Since the levels of adiponectin as well as its receptor are impaired in scleroderma patients with progressive fibrosis, the present results suggest a potential role for defective adiponectin expression or function in progressive fibrogenesis in scleroderma and other chronic fibrosing conditions. Restoring the adiponectin signaling axis in fibroblasts might, therefore, represent a novel pharmacological approach to controlling fibrosis.
Collapse
|
42
|
Wei J, Bhattacharyya S, Jain M, Varga J. Regulation of Matrix Remodeling by Peroxisome Proliferator-Activated Receptor-γ: A Novel Link Between Metabolism and Fibrogenesis. Open Rheumatol J 2012; 6:103-15. [PMID: 22802908 PMCID: PMC3396343 DOI: 10.2174/1874312901206010103] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2012] [Revised: 03/27/2012] [Accepted: 04/04/2012] [Indexed: 02/07/2023] Open
Abstract
The intractable process of fibrosis underlies the pathogenesis of systemic sclerosis (SSc) and other diseases, and in aggregate contributes to 45% of deaths worldwide. Because currently there is no effective anti-fibrotic therapy, a better understanding of the pathways and cellular differentiation programs underlying fibrosis are needed. Emerging evidence points to a fundamental role of the nuclear hormone receptor peroxisome proliferator activated receptor-γ (PPAR-γ) in modulating fibrogenesis. While PPAR-γ has long been known to be important in lipid metabolism and in glucose homeostasis, its role in regulating mesenchymal cell biology and its association with pathological fibrosis had not been appreciated until recently. This article highlights recent studies revealing a consistent association of fibrosis with aberrant PPAR-γ expression and activity in various forms of human fibrosis and in rodent models, and reviews studies linking genetic manipulation of the PPAR-γ pathway in rodents and fibrosis. We survey the broad range of anti-fibrotic activities associated with PPAR-γ and the underlying mechanisms. We also summarize the emerging data linking PPAR-γ dysfunction and pulmonary arterial hypertension (PAH), which together with fibrosis is responsible for the mortality in patients in SSc. Finally, we consider current and potential future strategies for targeting PPAR-γ activity or expression as a therapy for controlling fibrosis.
Collapse
Affiliation(s)
- Jun Wei
- Division of Rheumatology, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Swati Bhattacharyya
- Division of Rheumatology, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Manu Jain
- Respiratory and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - John Varga
- Division of Rheumatology, Northwestern University Feinberg School of Medicine, Chicago, USA
| |
Collapse
|
43
|
Lomonaco R, Ortiz-Lopez C, Orsak B, Webb A, Hardies J, Darland C, Finch J, Gastaldelli A, Harrison S, Tio F, Cusi K. Effect of adipose tissue insulin resistance on metabolic parameters and liver histology in obese patients with nonalcoholic fatty liver disease. Hepatology 2012; 55:1389-97. [PMID: 22183689 DOI: 10.1002/hep.25539] [Citation(s) in RCA: 308] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Accepted: 11/25/2011] [Indexed: 12/11/2022]
Abstract
UNLABELLED The role of adipose tissue insulin resistance in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) remains unclear. To evaluate this, we measured in 207 patients with NAFLD (age = 51 ± 1, body mass index = 34.1 ± 0.3 kg/m(2) ) and 22 controls without NAFLD (no NAFLD) adipose tissue insulin resistance by means of a validated index (Adipo-IR(i) = plasma free fatty acids [FFA] x insulin [FPI] concentration) and as the suppression of plasma FFA during an oral glucose tolerance test and by a low-dose insulin infusion. We also explored the relationship between adipose tissue insulin resistance with metabolic and histological parameters by dividing them based on quartiles of adipose tissue insulin resistance (Adipo-IR(i) quartiles: Q1 = more sensitive; Q4 = more insulin resistant). Hepatic insulin resistance, measured as an index derived from endogenous glucose production x FPI (HIRi), and muscle insulin sensitivity, were assessed during a euglycemic insulin clamp with 3-[(3) H] glucose. Liver fat was measured by magnetic resonance imaging and spectroscopy, and a liver biopsy was performed to assess liver histology. Compared to patients without steatosis, patients with NAFLD were insulin resistant at the level of adipose tissue, liver, and skeletal muscle and had higher plasma aspartate aminotransferase and alanine aminotransferase, triglycerides, and lower high-density lipoprotein cholesterol and adiponectin levels (all P < 0.01). Metabolic parameters, hepatic insulin resistance, and liver fibrosis (but not necroinflammation) deteriorated as quartiles of adipose tissue insulin resistance worsened (all P < 0.01). CONCLUSION Adipose tissue insulin resistance plays a key role in the development of metabolic and histological abnormalities of obese patients with NAFLD. Treatment strategies targeting adipose tissue insulin resistance (e.g., weight loss and thiazolidinediones) may be of value in this population.
Collapse
Affiliation(s)
- Romina Lomonaco
- Diabetes, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Cusi K. Role of obesity and lipotoxicity in the development of nonalcoholic steatohepatitis: pathophysiology and clinical implications. Gastroenterology 2012; 142:711-725.e6. [PMID: 22326434 DOI: 10.1053/j.gastro.2012.02.003] [Citation(s) in RCA: 619] [Impact Index Per Article: 51.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 01/04/2012] [Accepted: 02/02/2012] [Indexed: 02/07/2023]
Abstract
As obesity reaches epidemic proportions, nonalcoholic fatty liver disease (NAFLD) is becoming a frequent cause of patient referral to gastroenterologists. There is a close link between dysfunctional adipose tissue in NAFLD and common conditions such as metabolic syndrome, type 2 diabetes mellitus, and cardiovascular disease. This review focuses on the pathophysiology of interactions between adipose tissue and target organs in obesity and the resulting clinical implications for the management of nonalcoholic steatohepatitis. The release of fatty acids from dysfunctional and insulin-resistant adipocytes results in lipotoxicity, caused by the accumulation of triglyceride-derived toxic metabolites in ectopic tissues (liver, muscle, pancreatic beta cells) and subsequent activation of inflammatory pathways, cellular dysfunction, and lipoapoptosis. The cross talk between dysfunctional adipocytes and the liver involves multiple cell populations, including macrophages and other immune cells, that in concert promote the development of lipotoxic liver disease, a term that more accurately describes the pathophysiology of nonalcoholic steatohepatitis. At the clinical level, adipose tissue insulin resistance contributes to type 2 diabetes mellitus and cardiovascular disease. Treatments that rescue the liver from lipotoxicity by restoring adipose tissue insulin sensitivity (eg, significant weight loss, exercise, thiazolidinediones) or preventing activation of inflammatory pathways and oxidative stress (ie, vitamin E, thiazolidinediones) hold promise in the treatment of NAFLD, although their long-term safety and efficacy remain to be established. Better understanding of pathways that link dysregulated adipose tissue, metabolic dysfunction, and liver lipotoxicity will result in improvements in the clinical management of these challenging patients.
Collapse
Affiliation(s)
- Kenneth Cusi
- Division of Endocrinology, Diabetes and Metabolism, University of Florida, Gainesville, Florida 32610-0226, USA.
| |
Collapse
|
45
|
Shetty S, Ramos-Roman MA, Cho YR, Brown J, Plutzky J, Muise ES, Horton JD, Scherer PE, Parks EJ. Enhanced fatty acid flux triggered by adiponectin overexpression. Endocrinology 2012; 153:113-22. [PMID: 22045665 PMCID: PMC3249680 DOI: 10.1210/en.2011-1339] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 09/30/2011] [Indexed: 12/30/2022]
Abstract
Adiponectin overexpression in mice increases insulin sensitivity independent of adiposity. Here, we combined stable isotope infusion and in vivo measurements of lipid flux with transcriptomic analysis to characterize fatty acid metabolism in transgenic mice that overexpress adiponectin via the aP2-promoter (ADNTg). Compared with controls, fasted ADNTg mice demonstrated a 31% reduction in plasma free fatty acid concentrations (P = 0.008), a doubling of ketones (P = 0.028), and a 68% increase in free fatty acid turnover in plasma (15.1 ± 1.5 vs. 25.3 ± 6.8 mg/kg · min, P = 0.011). ADNTg mice had 2-fold more brown adipose tissue mass, and triglyceride synthesis and turnover were 5-fold greater in this organ (P = 0.046). Epididymal white adipose tissue was slightly reduced, possibly due to the approximately 1.5-fold increase in the expression of genes involved in oxidation (peroxisome proliferator-activated receptor α, peroxisome proliferator-activated receptor-γ coactivator 1α, and uncoupling protein 3). In ADNTg liver, lipogenic gene expression was reduced, but there was an unexpected increase in the expression of retinoid pathway genes (hepatic retinol binding protein 1 and retinoic acid receptor beta and adipose Cyp26A1) and liver retinyl ester content (64% higher, P < 0.02). Combined, these data support a physiological link between adiponectin signaling and increased efficiency of triglyceride synthesis and hydrolysis, a process that can be controlled by retinoids. Interactions between adiponectin and retinoids may underlie adiponectin's effects on intermediary metabolism.
Collapse
Affiliation(s)
- Shoba Shetty
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9052, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Liu YC, Gu XH. Roles and relation between C/EBPα and PARs in the activation of hepatic stellate cells. Shijie Huaren Xiaohua Zazhi 2011; 19:3656-3660. [DOI: 10.11569/wcjd.v19.i36.3656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Protease activated receptors (PARs) are main components of the fibrotic cascade mediated by the trypsin and thrombin that amplifies liver inflammation and fibrosis. Gene transcription initiation induced by PARs plays an important role in the activation of hepatic stellate cells (HSCs). HSC activation can be inhibited by the expression of transcription factor CCAAT enhancer binding proteins α (C/EBPα). Further research of the relation between C/EBPα and PARs will contribute to the understanding of the pathogenesis of liver fibrosis and provide a theoretical basis for further exploration of anti-fibrotic strategies.
Collapse
|
47
|
Peroxisome proliferator-activated receptor-γ cross-regulation of signaling events implicated in liver fibrogenesis. Cell Signal 2011; 24:596-605. [PMID: 22108088 DOI: 10.1016/j.cellsig.2011.11.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 11/02/2011] [Indexed: 12/20/2022]
Abstract
Peroxisome proliferator-activated receptor-γ (PPARγ) is a nuclear receptor with transcriptional activity controlling multiple physical and pathological processes. Recently, PPARγ has been implicated in the pathogenesis of liver fibrosis. Its depleted expression has strong associations with the activation and transdifferentiation of hepatic stellate cells, the central event in liver fibrogenesis. Studies over the past decade demonstrate that PPARγ cross-regulates a number of signaling pathways mediated by growth factors and adipokines, and cellular events including apoptosis and senescence. These signaling and cellular events and their molecular interactions with PPARγ system are profoundly involved in liver fibrogenesis. We critically summarize these mechanistic insights into the PPARγ regulation in liver fibrogenesis based on the updated findings in this area. We conclude with a discussion of the impacts of these discoveries on the interpretation of liver fibrogenesis and their potential therapeutic implications. PPARγ activation could be a promising strategy for antifibrotic therapy.
Collapse
|