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Saigo Y, Uno K, Ishigure T, Odake T, Ohta T. Pathophysiological Features of Rat Models of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis. In Vivo 2024; 38:990-999. [PMID: 38688597 PMCID: PMC11059886 DOI: 10.21873/invivo.13532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/03/2024] [Accepted: 03/04/2024] [Indexed: 05/02/2024]
Abstract
Nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) is caused by various factors, including genetic and/or environmental factors, and has complicated pathophysiological features during the development of the disease. NAFLD/NASH is recognized as an unmet medical need, and NAFLD/NASH animal models are essential tools for developing new therapies, including potential drugs and biomarkers. In this review, we describe the pathological features of the NAFLD/NASH rat models, focusing on the histopathology of hepatic fibrosis. NAFLD/NASH rat models are divided into three categories: diet-induced, genetic, and combined models based on diet, chemicals, and genetics. Rat models of NASH with hepatic fibrosis are especially expected to contribute to the development of new therapies, such as drugs and biomarkers.
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Affiliation(s)
- Yasuka Saigo
- Laboratory of Animal Physiology and Functional Anatomy, Graduate School of Agriculture, Kyoto University, Kyoto, Japan;
- Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Osaka, Japan
| | - Kinuko Uno
- Laboratory of Animal Physiology and Functional Anatomy, Graduate School of Agriculture, Kyoto University, Kyoto, Japan;
| | - Tatsuya Ishigure
- Laboratory of Animal Physiology and Functional Anatomy, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., Osaka, Japan
| | - Tatsumi Odake
- Laboratory of Animal Physiology and Functional Anatomy, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Takeshi Ohta
- Laboratory of Animal Physiology and Functional Anatomy, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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Yang CC, Wu CH, Lin TC, Cheng YN, Chang CS, Lee KT, Tsai PJ, Tsai YS. Inhibitory effect of PPARγ on NLRP3 inflammasome activation. Am J Cancer Res 2021; 11:2424-2441. [PMID: 33500734 PMCID: PMC7797672 DOI: 10.7150/thno.46873] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 11/19/2020] [Indexed: 12/21/2022] Open
Abstract
Rationale: Stimulation of the NLRP3 inflammasome by metabolic byproducts is known to result in inflammatory responses and metabolic diseases. However, how the host controls aberrant NLRP3 inflammasome activation remains unclear. PPARγ, a known regulator of energy metabolism, plays an anti-inflammatory role through the inhibition of NF-κB activation and additionally attenuates NLRP3-dependent IL-1β and IL-18 production. Therefore, we hypothesized that PPARγ serves as an endogenous modulator that attenuates NLRP3 inflammasome activation in macrophages. Methods: Mouse peritoneal macrophages with exposure to a PPARγ agonist at different stages and the NLRP3 inflammasome-reconstituted system in HEK293T cells were used to investigate the additional anti-inflammatory effect of PPARγ on NLRP3 inflammasome regulation. Circulating mononuclear cells of obese patients with weight-loss surgery were used to identify the in vivo correlation between PPARγ and the NLRP3 inflammasome. Results: Exposure to the PPARγ agonist, rosiglitazone, during the second signal of NLRP3 inflammasome activation attenuated caspase-1 and IL-1β maturation. Moreover, PPARγ interfered with NLRP3 inflammasome formation by decreasing NLRP3-ASC and NLRP3-NLRP3 interactions as well as NLRP3-dependent ASC oligomerization, which is mediated through interaction between the PPARγ DNA-binding domain and the nucleotide-binding and leucine-rich repeat domains of NLRP3. Furthermore, PPARγ was required to limit metabolic damage-associated molecular pattern-induced NLRP3 inflammasome activation in mouse macrophages. Finally, the mature caspase-1/PPARγ ratio was reduced in circulating mononuclear cells of obese patients after weight-loss surgery, which we define as an “NLRP3 accelerating index”. Conclusions: These results revealed an additional anti-inflammatory role for PPARγ in suppressing NLRP3 inflammasome activation through interaction with NLRP3. Thus, our study highlights that PPARγ agonism may be a therapeutic option for targeting NLRP3-related metabolic diseases.
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Al Mamun A, Wu Y, Jia C, Munir F, Sathy KJ, Sarker T, Monalisa I, Zhou K, Xiao J. Role of pyroptosis in liver diseases. Int Immunopharmacol 2020; 84:106489. [PMID: 32304992 DOI: 10.1016/j.intimp.2020.106489] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/03/2020] [Accepted: 04/05/2020] [Indexed: 12/17/2022]
Abstract
Pyroptosis is known as a novel form of pro-inflammatory cell death program, which is exceptional from other types of cell death programs. Particularly, pyroptosis is characterized by Gasdermin family-mediated pore formation and subsequently cellular lysis, also release of several pro-inflammatory intracellular cytokines. In terms of mechanism, there are two signaling pathways involved in pyroptosis, including caspase-1, and caspase-4/5/11 mediated pathways. However, pyroptosis plays important roles in immune defense mechanisms. Recent studies have demonstrated that pyroptosis plays significant roles in the development of liver diseases. In our review, we have focused on the role of pyroptosis based on the molecular and pathophysiological mechanisms in the development of liver diseases. We have also highlighted targeting of pyroptosis for the therapeutic implications in liver diseases in the near future.
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Affiliation(s)
- Abdullah Al Mamun
- Molecular Pharmacology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Yanqing Wu
- Institute of Life Sciences, Wenzhou University, Wenzhou 325035, Zhejiang Province, China
| | - Chang Jia
- Pediatric Research Institute, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou 325027, Zhejiang Province, China
| | - Fahad Munir
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
| | - Kasfia Jahan Sathy
- Department of Pharmacy, North South University, Bashundhara, Dhaka 1229, Bangladesh
| | - Tamanna Sarker
- Department of Pharmacy, Southeast University, Banani, Dhaka 1213, Bangladesh
| | - Ilma Monalisa
- Department of Pharmacy, Southeast University, Banani, Dhaka 1213, Bangladesh
| | - Kailiang Zhou
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou 325027, Zhejiang Province, China
| | - Jian Xiao
- Molecular Pharmacology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China.
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Chen X, Tan XR, Li SJ, Zhang XX. LncRNA NEAT1 promotes hepatic lipid accumulation via regulating miR-146a-5p/ROCK1 in nonalcoholic fatty liver disease. Life Sci 2019; 235:116829. [PMID: 31484042 DOI: 10.1016/j.lfs.2019.116829] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/26/2019] [Accepted: 08/31/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Nonalcoholic fatty liver disease (NAFLD) is a severe liver disease, which influences the health of people worldwide. However, the specific mechanism of the disease remains unknown, and effective treatments are still lacking. It was reported that Nuclear enriched abundant transcript 1 (NEAT1) obviously was up-regulated in NAFLD model. But the role and underlying mechanism of NEAT1 in NAFLD is unclear. METHODS HepG2 cells were treated by free fatty acids (FFA) and C57BL/6J mice were treated by high-fat diet to establish NAFLD in vitro and in vivo models, respectively. Cell transfection was applied to regulate the expression of NEAT1, ROCK1, and miR-146a-5p. Western blotting and qRT-PCR were used for measuring expression of protein and mRNA level, respectively. Dual luciferase assay was used to detect the target relationship. Oil Red O staining was used to measure the lipid accumulation. HE staining was used for observing pathological feature of liver tissues. RESULTS High levels of NEAT1 and ROCK1, and low level of miR-146a-5p were identified in NAFLD models. NEAT1 could target miR-146a-5p to promote ROCK1 expression. Knockdown of NEAT1, overexpression of miR-146a-5p and knockdown of ROCK1 inhibited lipid accumulation through activating AMPK pathway. CONCLUSION NEAT1 may regulate NAFLD through miR-146a-5p targeting ROCK1, and further affect AMPK/SREBP pathway. This study may provide a new thought for the treatment of NAFLD.
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Affiliation(s)
- Xi Chen
- Department of Pediatrics, The Second Xiangya Hospital, Central South Univeristy, Changsha 410011, Hunan Province, PR China
| | - Xin-Rui Tan
- Department of Pediatrics, The Second Xiangya Hospital, Central South Univeristy, Changsha 410011, Hunan Province, PR China
| | - Shi-Jun Li
- Department of Pediatrics, The Second Xiangya Hospital, Central South Univeristy, Changsha 410011, Hunan Province, PR China
| | - Xing-Xing Zhang
- Department of Pediatrics, The Second Xiangya Hospital, Central South Univeristy, Changsha 410011, Hunan Province, PR China.
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Sun Y, Song Y, Liu C, Geng J. LncRNA NEAT1-MicroRNA-140 axis exacerbates nonalcoholic fatty liver through interrupting AMPK/SREBP-1 signaling. Biochem Biophys Res Commun 2019; 516:584-590. [PMID: 31239155 DOI: 10.1016/j.bbrc.2019.06.104] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 06/18/2019] [Indexed: 12/25/2022]
Abstract
BACKGROUND Nonalcoholic fatty liver disease (NAFLD) is a severe liver disease, which influences the health of people worldwide. However, the mechanism modulating the pathogenesis of NAFLD remains elusive. It was reported that nuclear enriched abundant transcript 1 (NEAT1) and microRNA-140 (miR-140) could regulate lipogenesis, but whether they could influence NAFLD are still unknown. METHODS HepG2 cells were treated by free fatty acids (FFA) to establish the model of NAFLD in vitro, and C57 mice were treated by high-fat diet to establish the model of NAFLD in vivo. Cell transfection was applied to regulate the expression of NEAT1 and miR-140. Western blotting and qRT-PCR were applied for measuring expression of protein and mRNA, respectively. HE staining and Oil Red O staining were used for observing liver tissues. RESULTS NEAT1 and miR-140 are upregulated in hepacytes under the NAFLD conditions. NEAT1 directly binds to miR-140 and acts synergistically with miR-140 to exacerbate the progression of NAFLD. Reciprocally, silence of miR-140 or NEAT1 alleviates the severity of NAFLD. The mechanistical study shows that the axis of NEAT1-miR-140 inactivates AMPK/SREBP-1 signaling during the NAFLD. . CONCLUSION The NEAT1-miR-140 axis play a crucial role in modulation of NAFLD via inactivation of AMPK/SREBP1 signaling. This study may provide a novel insight for the treatment of NAFLD.
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Affiliation(s)
- Yunfu Sun
- Department of Hepatobiliary Surgery, Weihai Municipal Hospital Affiliated to Dalian Medical University, Weihai, China.
| | - Yu Song
- Department of Hepatobiliary Surgery, Weihai Municipal Hospital Affiliated to Dalian Medical University, Weihai, China
| | - Changsheng Liu
- The Second Department of General Surgery, Southern Ward of Weihai Municipal Hospital Affiliated to Dalian Medical University, Weihai, China
| | - Jianli Geng
- Department of Hepatobiliary Surgery, Weihai Municipal Hospital Affiliated to Dalian Medical University, Weihai, China
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Metformin potentiates cognitive and antidepressant effects of fluoxetine in rats exposed to chronic restraint stress and high fat diet: potential involvement of hippocampal c-Jun repression. Naunyn Schmiedebergs Arch Pharmacol 2018; 391:407-422. [PMID: 29379991 DOI: 10.1007/s00210-018-1466-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 01/09/2018] [Indexed: 12/15/2022]
Abstract
Several hypotheses link high fat diet (HFD) with the pathophysiology of depression and its response to antidepressants. This study aimed to determine the effect of metformin (MET) on the cognitive and antidepressant activity of fluoxetine (FLU) through its effect on c-Jun expression. Behavioral, cognitive function, biochemical, and histopathological studies were performed in non-HFD- and HFD-fed rats exposed to chronic restraint stress (CRS). Stressed group showed cognitive impairment, depressive-like symptoms, disturbed glucose homeostasis and lipid profile, reduced adiponectin level, brain-derived neurotrophic factor (BDNF) expression, and increased corticosterone and c-Jun. All these were aggravated by HFD. MET, FLU and their combination produced significant improvement in lipid profile with significant increase in adiponectin and BDNF expression. Corticosterone, body weight and insulin resistance showed significant decrease in the treated groups. Moreover, there was a significant decrease in hippocampal c Jun expression. There was a significant preferable effect toward the combination. Conclusion, MET may decrease the refractoriness to FLU and improves the cognition in individuals who are fed on HFD.
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Zhou F, Zhang Y, Chen J, Hu Y, Xu Y. Verapamil Ameliorates Hepatic Metaflammation by Inhibiting Thioredoxin-Interacting Protein/NLRP3 Pathways. Front Endocrinol (Lausanne) 2018; 9:640. [PMID: 30429827 PMCID: PMC6220071 DOI: 10.3389/fendo.2018.00640] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 10/09/2018] [Indexed: 12/12/2022] Open
Abstract
Activation of thioredoxin-interacting protein (TXNIP)/nod-like receptor protein 3 (NLRP3) inflammasome plays a critical role in pathogenesis of non-alcoholic fatty liver disease. This study investigated the protective effects of verapamil on hepatic metaflammation in a rodent model of high-fat (HF) diet-induced obesity (DIO). DIO was induced in a subset of mice provided with HF diet (45% kcal fat). After 10 weeks of HF diet, verapamil was administered by intraperitoneal injection. The experimental groups included the following: (1) normal diet group, (2) normal diet + treatment with verapamil (VER) group, (3) HF control group, (4) HF+VER (25 mg/kg/day) group. After 1 week of each treatment, blood and liver tissues were collected, and glucose control, serum triglyceride (TG) level, inflammation, and TXNIP/NLRP3 inflammasome were analyzed. Verapamil administration caused no alteration in food intake. HF diet impaired glucose control and increased body weight and serum TG levels. Hepatic inflammation was aggravated in HF-fed mice, as demonstrated by increased levels of pro-inflammatory markers interleukin-1β (IL-1β) and IL-18 in the liver. On the other hand, verapamil administration significantly improved glucose control, body weight, and serum TG levels. Verapamil treatment also reduced pro-inflammatory marker levels. These improvements were accompanied by alterations in activation of TXNIP/NLRP3 inflammasome. The observed results demonstrate that verapamil ameliorates hepatic metaflammation by inhibiting TXNIP/NLRP3 pathways.
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Affiliation(s)
- Feng Zhou
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, China
- Department of Endocrinology, Puren Hospital, Wuhan University of Science and Technology, Wuhan, China
| | - Ying Zhang
- Department of Critical Care Medicine, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Jing Chen
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yimeng Hu
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yancheng Xu
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, China
- *Correspondence: Yancheng Xu
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Borai IH, Shaker Y, Kamal MM, Ezzat WM, Ashour E, Afify M, Gouda W, Elbrashy MM. Evaluation of Biomarkers in Egyptian Patients with Different Grades of Nonalcoholic Fatty Liver Disease. J Clin Transl Hepatol 2017; 5:109-118. [PMID: 28660148 PMCID: PMC5472931 DOI: 10.14218/jcth.2017.00004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/02/2017] [Accepted: 04/17/2017] [Indexed: 12/13/2022] Open
Abstract
Background and Aims: Nonalcoholic fatty liver disease (NAFLD) is a silent disease; its spectrum includes simple steatosis, nonalcoholic steatohepatitis and fibrosis. Pro- and anti-inflammatory cytokines play roles in the pathogenesis of NAFLD and insulin resistance (IR). Moreover, plasma cell antigen-1 (PC-1) is related to IR and associated with NAFLD progression. Therefore, we aimed to detect biomarkers, ultrasonographic and anthropometric findings capable of differentiating NAFLD grades, since most previous investigators were concerned more with NAFLD patients without classifying them into grades. Methods: A total of 87 NAFLD patients (31 with grade 1 (mild NAFLD), 26 with grade 2 (moderate NAFLD) and 30 with grade 3 (severe NAFLD) were included in the study, in addition to 47 controls (grade 0). All subjects underwent ultrasonographic examination for NAFLD diagnosis. Serum interleukin-10 (IL-10), plasma interleukin-18 (IL-18) and plasma PC-1 levels were determined using enzyme-linked immunosorbent assay. Results: Homoeostasis model assessment (HOMA)-IR was higher in different NAFLD grades than in controls. Ultrasonographic and anthropometric findings and lipid profile indices (except for high-density lipoprotein cholesterol, which was decreased) were increased with NAFLD progression. Grade 3 patients showed significant increase in levels of IL-18 and significant decrease in IL-10 and PC-1 levels when compared to grade 1 patients. Conclusion: Anthropometric and ultrasonographic findings were valuable in differentiating NAFLD grades. IR is very important in NAFLD pathogenesis. IL-18, HOMA-index and PC-1 levels could be used to differentiate between NAFLD grades, together with other measurements.
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Affiliation(s)
- Ibrahim H. Borai
- Biochemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Yehia Shaker
- Biochemistry Department, National Research Centre, Giza, Egypt
- *Correspondence to: Yehia Shaker, Biochemistry Department, National Research Center, ElBuhous St, Dokki, Giza 12622, Egypt. Tel: +201-223715781, Fax: +202-33460627, E-mail:
| | - Maha Moustafa Kamal
- Biochemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Wafaa M. Ezzat
- Department of Internal Medicine, National Research Center, Giza, Egypt
| | - Esmat Ashour
- Biochemistry Department, National Research Centre, Giza, Egypt
| | - Mie Afify
- Biochemistry Department, National Research Centre, Giza, Egypt
| | - Weaam Gouda
- Biochemistry Department, National Research Centre, Giza, Egypt
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Tsuchiya S, Amano Y, Isono O, Imai M, Shimizu F, Asada M, Imai S, Harada A, Yasuhara Y, Tozawa R, Nagabukuro H. Pharmacological evaluation of pioglitazone and candesartan cilexetil in a novel mouse model of non-alcoholic steatohepatitis, modified choline-deficient, amino acid-defined diet fed low-density lipoprotein receptor knockout mice. Hepatol Res 2017; 47:584-592. [PMID: 27421062 DOI: 10.1111/hepr.12773] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/28/2016] [Accepted: 07/12/2016] [Indexed: 02/08/2023]
Abstract
AIM Low-density lipoprotein receptor knockout (LDLR-KO) mice fed a modified choline-deficient and amino acid-defined (mCDAA) diet show non-alcoholic steatohepatitis (NASH)-like pathophysiology. In order to pharmacologically benchmark this model, effects of pioglitazone (a thiazolidinedione) and candesartan cilexetil (an angiotensin II type 1 receptor blocker) on steatosis and liver fibrosis were examined. METHODS Pioglitazone (10 mg/kg) and candesartan cilexetil (3 mg/kg) were given orally once daily to LDLR-KO mice under mCDAA diet for 7 weeks. Blood biochemistry and hepatic histology were assessed, and hepatic gene expression levels and triglyceride content were measured. RESULTS Pioglitazone suppressed hepatic COL1A1 gene expression by 43% and attenuated hepatic fibrosis areas by 49%. Pioglitazone also decreased plasma alanine aminotransferase levels, liver weight, hepatic triglyceride content, and hepatic expression of other fibrosis-related genes such as TGFB1, SPP1, TIMP1, and IL6. Candesartan cilexetil suppressed hepatic COL1A1 gene expression by 33%, whereas the other end-points including hepatic fibrosis areas were not affected. CONCLUSIONS Pioglitazone showed anti-fibrotic effects accompanied by improving hepatic transaminase activity and hepatic lipid accumulation, but the effect of candesartan cilexetil was only limited, unlike previous reports for angiotensin II type 1 receptor blockers. As the pharmacological effects of pioglitazone in the current animal model are similar to those reported in patients with NASH, this model may represent some aspects of the pathophysiology of NASH. Further profiling using other agents or mechanisms that have been tested in the clinic will better clarify the utility of the animal model.
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Affiliation(s)
- Shuntarou Tsuchiya
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Yuichiro Amano
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Osamu Isono
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Mayumi Imai
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Fumi Shimizu
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Mari Asada
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Shigemitsu Imai
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Ayako Harada
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Yoshitaka Yasuhara
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Ryuichi Tozawa
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Hiroshi Nagabukuro
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
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Magdy YM, El-Kharashi OA, Nabih ES, Shaker SM, Abd-Elaziz LF, Aboul-Fotouh S. Potential involvement of JNK1 repression in the hepatic effect of sitagliptin and metformin in rats subjected to high fat diet and chronic mild distress. Biomed Pharmacother 2017; 85:225-238. [DOI: 10.1016/j.biopha.2016.10.098] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 10/30/2016] [Accepted: 10/31/2016] [Indexed: 12/16/2022] Open
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Isocaloric Pair-Fed High-Carbohydrate Diet Induced More Hepatic Steatosis and Inflammation than High-Fat Diet Mediated by miR-34a/SIRT1 Axis in Mice. Sci Rep 2015; 5:16774. [PMID: 26608583 PMCID: PMC4660435 DOI: 10.1038/srep16774] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/07/2015] [Indexed: 02/08/2023] Open
Abstract
To investigate the different effects of isocaloric high-fat diet (HFD) and high-carbohydrate diet (HCD) on hepatic steatosis and the underlying mechanisms, especially the role of microRNA-34a/silent information regulator T1 (SIRT1) axis, C57BL/6J mice (n = 12/group) were isocaloric pair-fed with Lieber-DeCarli liquid diet containing either high fat (HFLD) or high carbohydrate (HCLD) for 16 weeks. As compared to the HFLD fed mice, despite the similar final body weights, HCLD feeding: (1) induced more severe hepatic steatosis; (2) up-regulated hepatic expression of miR-34a accompanied with significant decrease of SIRT1 and nicotinamide phosphoribosyltransferase (NAMPT), SIRT1 activity and phosphorylation of AMPK; (3) up-regulated de novo lipogenesis (DNL) related proteins expression (ACC, SCD1), and down-regulated expressions of miR-122, miR-370 and miR-33; (4) decreased mRNA expressions of genes Cpt1, Pparα and Pgc1α related to fatty acid oxidation; (5) increased hepatic total cholesterol concentration and decreased expression of cholesterol metabolism related genes Abcg5, Abcg8, Abcg11, Cyp7a1 and Cyp8b1; and (6) induced higher hepatic inflammatory response accompanied with significant increased mRNA expressions of Il1β, Tnfα and Mcp1. Thus, isocaloric HCLD feeding induced greater severity in hepatic steatosis and inflammatory response than HFLD feeding, potentially through miR-34a/SIRT1 axis mediated promotion of DNL, inhibition of fatty acid oxidation and cholesterol metabolism.
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LI XIULI, LI JIN, LU XIAOLAN, MA HUIHUI, SHI HAITAO, LI HONG, XIE DANHONG, DONG LEI, LIANG CHUNLIAN. Treatment with PPARδ agonist alleviates non-alcoholic fatty liver disease by modulating glucose and fatty acid metabolic enzymes in a rat model. Int J Mol Med 2015; 36:767-75. [DOI: 10.3892/ijmm.2015.2270] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 06/11/2015] [Indexed: 11/06/2022] Open
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13
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Soares e Silva AK, de Oliveira Cipriano Torres D, dos Santos Gomes FO, dos Santos Silva B, Lima Ribeiro E, Costa Oliveira A, dos Santos LAM, de Lima MDCA, Pitta IDR, Peixoto CA. LPSF/GQ-02 inhibits the development of hepatic steatosis and inflammation in a mouse model of non-alcoholic fatty liver disease (NAFLD). PLoS One 2015; 10:e0123787. [PMID: 25875942 PMCID: PMC4397012 DOI: 10.1371/journal.pone.0123787] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 03/08/2015] [Indexed: 02/07/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) defines a wide spectrum of liver diseases that extends from simple steatosis to non-alcoholic steatohepatitis. Although the pathogenesis of NAFLD remains undefined, it is recognized that insulin resistance is present in almost all patients who develop this disease. Thiazolidinediones (TZDs) act as an insulin sensitizer and have been used in the treatment of patients with type 2 diabetes and other insulin-resistant conditions, including NAFLD. Hence, therapy of NAFLD with insulin-sensitizing drugs should ideally improve the key hepatic histological changes, while also reducing cardiometabolic and cancer risks. Controversially, TZDs are associated with the development of cardiovascular events and liver problems. Therefore, there is a need for the development of new therapeutic strategies to improve liver function in patients with chronic liver diseases. The aim of the present study was to assess the therapeutic effects of LPSF/GQ-02 on the liver of LDLR-/- mice after a high-fat diet. Eighty male mice were divided into 4 groups and two different experiments: 1-received a standard diet; 2-fed with a high-fat diet (HFD); 3–HFD+pioglitazone; 4–HFD+LPSF/GQ-02. The experiments were conducted for 10 or 12 weeks and in the last two or four weeks respectively, the drugs were administered daily by gavage. The results obtained with an NAFLD murine model indicated that LPSF/GQ-02 was effective in improving the hepatic architecture, decreasing fat accumulation, reducing the amount of collagen, decreasing inflammation by reducing IL-6, iNOS, COX-2 and F4 / 80, and increasing the protein expression of IκBα, cytoplasmic NFκB-65, eNOS and IRS-1 in mice LDLR -/-. These results suggest a direct action by LPSF/GQ-02 on the factors that affect inflammation, insulin resistance and fat accumulation in the liver of these animals. Further studies are being conducted in our laboratory to investigate the possible mechanism of action of LPSF/GQ-02 on hepatic lipid metabolism.
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Affiliation(s)
| | | | | | - Bruna dos Santos Silva
- Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), Pernambuco, Recife, Brazil
| | - Edlene Lima Ribeiro
- Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), Pernambuco, Recife, Brazil
| | - Amanda Costa Oliveira
- Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), Pernambuco, Recife, Brazil
| | | | - Maria do Carmo Alves de Lima
- Laboratório de planejamento e síntese de fármacos, Universidade federal de Pernambuco, Pernambuco, Recife, Brazil
| | - Ivan da Rocha Pitta
- Laboratório de planejamento e síntese de fármacos, Universidade federal de Pernambuco, Pernambuco, Recife, Brazil
| | - Christina Alves Peixoto
- Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), Pernambuco, Recife, Brazil
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Stojsavljević S, Gomerčić Palčić M, Virović Jukić L, Smirčić Duvnjak L, Duvnjak M. Adipokines and proinflammatory cytokines, the key mediators in the pathogenesis of nonalcoholic fatty liver disease. World J Gastroenterol 2014; 20:18070-18091. [PMID: 25561778 PMCID: PMC4277948 DOI: 10.3748/wjg.v20.i48.18070] [Citation(s) in RCA: 214] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 10/22/2014] [Accepted: 11/19/2014] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a condition in which excess fat accumulates in the liver of a patient with no history of alcohol abuse or other causes for secondary hepatic steatosis. The pathogenesis of NAFLD and nonalcoholic steatohepatitis (NASH) has not been fully elucidated. The “two-hit“ hypothesis is probably a too simplified model to elaborate complex pathogenetic events occurring in patients with NASH. It should be better regarded as a multiple step process, with accumulation of liver fat being the first step, followed by the development of necroinflammation and fibrosis. Adipose tissue, which has emerged as an endocrine organ with a key role in energy homeostasis, is responsive to both central and peripheral metabolic signals and is itself capable of secreting a number of proteins. These adipocyte-specific or enriched proteins, termed adipokines, have been shown to have a variety of local, peripheral, and central effects. In the current review, we explore the role of adipocytokines and proinflammatory cytokines in the pathogenesis of NAFLD. We particularly focus on adiponectin, leptin and ghrelin, with a brief mention of resistin, visfatin and retinol-binding protein 4 among adipokines, and tumor necrosis factor-α, interleukin (IL)-6, IL-1, and briefly IL-18 among proinflammatory cytokines. We update their role in NAFLD, as elucidated in experimental models and clinical practice.
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Mehta R, Neupane A, Wang L, Goodman Z, Baranova A, Younossi ZM. Expression of NALPs in adipose and the fibrotic progression of non-alcoholic fatty liver disease in obese subjects. BMC Gastroenterol 2014; 14:208. [PMID: 25512222 PMCID: PMC4279907 DOI: 10.1186/s12876-014-0208-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 11/27/2014] [Indexed: 12/14/2022] Open
Abstract
Background Visceral obesity is often accompanied by non-alcoholic fatty liver disease (NAFLD). Activation of NACHT, LRR and PYD domains-containing proteins (NALPs) may contribute to the release of pro-inflammatory cytokines by adipose and the obesity-associated progression of NAFLD to non-alcoholic steatohepatitis (NASH). Methods We analyzed visceral adipose expression of various NALPs and its downstream effectors caspase-1, ASC (Apoptosis-associated speck-like protein containing a CARD), IL-18 (Interleukin-18) and IL-1β (Interleukin- 1Beta) in obese subjects (BMI ≥ 35) with biopsy proven NAFLD. Results In adipose samples collected from NASH and pericellular fibrosis patients cohorts, expression levels of NALPs and IL-1β were lower than that in non-NASH patients. In portal fibrosis, the levels of mRNA encoding anti-inflammatory NALP6 were upregulated. The expression levels of all NALPs were significantly co-correlated. Circulating IL-18 levels were associated with increased liver injury markers AST and ALT and portal fibrosis. Conclusion Our observations point at a possible shift in inflammation and fibrotic response from adipose tissue to liver and a possible negative feedback regulation of tissue inflammation that may instigate NAFLD severity. Electronic supplementary material The online version of this article (doi:10.1186/s12876-014-0208-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rohini Mehta
- Betty and Guy Beatty Obesity and Liver Program, Inova Health System, Falls Church, VA, USA. .,Center for the Study of Chronic Metabolic Diseases, School of Systems Biology, College of Science, George Mason University, Fairfax, VA, USA.
| | - Arpan Neupane
- Betty and Guy Beatty Obesity and Liver Program, Inova Health System, Falls Church, VA, USA. .,Center for the Study of Chronic Metabolic Diseases, School of Systems Biology, College of Science, George Mason University, Fairfax, VA, USA.
| | - Lei Wang
- Betty and Guy Beatty Obesity and Liver Program, Inova Health System, Falls Church, VA, USA. .,Center for the Study of Chronic Metabolic Diseases, School of Systems Biology, College of Science, George Mason University, Fairfax, VA, USA.
| | - Zachary Goodman
- Betty and Guy Beatty Obesity and Liver Program, Inova Health System, Falls Church, VA, USA. .,Center for Liver Diseases and Department of Medicine, Inova Fairfax Hospital, Falls Church, VA, USA.
| | - Ancha Baranova
- Betty and Guy Beatty Obesity and Liver Program, Inova Health System, Falls Church, VA, USA. .,Center for the Study of Chronic Metabolic Diseases, School of Systems Biology, College of Science, George Mason University, Fairfax, VA, USA.
| | - Zobair M Younossi
- Betty and Guy Beatty Obesity and Liver Program, Inova Health System, Falls Church, VA, USA. .,Center for Liver Diseases and Department of Medicine, Inova Fairfax Hospital, Falls Church, VA, USA.
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Rosiglitazone inhibits hepatic insulin resistance induced by chronic pancreatitis and IKK-β/NF-κB expression in liver. Pancreas 2014; 43:1291-8. [PMID: 25036911 DOI: 10.1097/mpa.0000000000000173] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES This study aimed to investigate the influence of rosiglitazone on hepatic insulin resistance and the expressions of IκB kinase-β (IKK-β)/nuclear factor-κB (NF-κB) in chronic pancreatitis (CP). METHODS After CP was induced in rats, rosiglitazone and GW9662 were administered at the doses of 4 and 2 mg/kg per day for 4 weeks, respectively. Then, glucose and insulin tolerance tests were performed. Hepatocytes were isolated for the glucose release experiments. Determination of the IKK-β, NF-κB, and Ser307p-insulin receptor substrates-1 (Ser307p-IRS-1) expression in the liver was performed. RESULTS The increased plasma glucose, reduced insulin sensitivity, and the capacity of insulin to suppress glucose release in hepatocytes were observed in CP rats. The IKK-β, NF-κB, and Ser307p-IRS-1 expressions were significantly higher in the liver of CP rats than in sham-operated rats (P < 0.05). Rosiglitazone treatment significantly improved hepatic insulin sensitivity and inhibited the IKK-β, NF-κB, and Ser307p-IRS-1 expressions in the liver (P < 0.05). Counteraction with peroxisome proliferator-activated receptor-γ by GW9662 attenuated the aforementioned effects of rosiglitazone. CONCLUSIONS Rosiglitazone attenuates hepatic insulin resistance induced by CP. The inhibition of hepatic IKK-β and NF-κB expressions via peroxisome proliferator-activated receptor-γ may be involved in the therapeutic effect of rosiglitazone.
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Lazic M, Inzaugarat ME, Povero D, Zhao IC, Chen M, Nalbandian M, Miller YI, Cherñavsky AC, Feldstein AE, Sears DD. Reduced dietary omega-6 to omega-3 fatty acid ratio and 12/15-lipoxygenase deficiency are protective against chronic high fat diet-induced steatohepatitis. PLoS One 2014; 9:e107658. [PMID: 25251155 PMCID: PMC4175074 DOI: 10.1371/journal.pone.0107658] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 08/13/2014] [Indexed: 02/07/2023] Open
Abstract
Obesity is associated with metabolic perturbations including liver and adipose tissue inflammation, insulin resistance, and type 2 diabetes. Omega-6 fatty acids (ω6) promote and omega-3 fatty acids (ω3) reduce inflammation as they can be metabolized to pro- and anti-inflammatory eicosanoids, respectively. 12/15-lipoxygenase (12/15-LO) enzymatically produces some of these metabolites and is induced by high fat (HF) diet. We investigated the effects of altering dietary ω6/ω3 ratio and 12/15-LO deficiency on HF diet-induced tissue inflammation and insulin resistance. We examined how these conditions affect circulating concentrations of oxidized metabolites of ω6 arachidonic and linoleic acids and innate and adaptive immune system activity in the liver. For 15 weeks, wild-type (WT) mice were fed either a soybean oil-enriched HF diet with high dietary ω6/ω3 ratio (11∶1, HFH), similar to Western-style diet, or a fat Kcal-matched, fish oil-enriched HF diet with a low dietary ω6/ω3 ratio of 2.7∶1 (HFL). Importantly, the total saturated, monounsaturated and polyunsaturated fat content was matched in the two HF diets, which is unlike most published fish oil studies in mice. Despite modestly increased food intake, WT mice fed HFL were protected from HFH-diet induced steatohepatitis, evidenced by decreased hepatic mRNA expression of pro-inflammatory genes and genes involved in lymphocyte homing, and reduced deposition of hepatic triglyceride. Furthermore, oxidized metabolites of ω6 arachidonic acid were decreased in the plasma of WT HFL compared to WT HFH-fed mice. 12/15-LO knockout (KO) mice were also protected from HFH-induced fatty liver and elevated mRNA markers of inflammation and lymphocyte homing. 12/15-LOKO mice were protected from HFH-induced insulin resistance but reducing dietary ω6/ω3 ratio in WT mice did not ameliorate insulin resistance or adipose tissue inflammation. In conclusion, lowering dietary ω6/ω3 ratio in HF diet significantly reduces steatohepatitis.
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Affiliation(s)
- Milos Lazic
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
| | | | - Davide Povero
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
| | - Iris C. Zhao
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Mark Chen
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Madlena Nalbandian
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Yury I. Miller
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | | | - Ariel E. Feldstein
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
| | - Dorothy D. Sears
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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Sanyal AJ. An integrated view of liver injury and disease progression in nonalcoholic steatohepatitis. Hepatol Int 2013. [PMID: 26202294 DOI: 10.1007/s12072-013-9479-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the most common cause of chronic liver disease globally. NAFLD represents a host of pathophysiologic mechanisms that culminate in the accumulation of fat, in a predominantly macrovesicular pattern, in the liver along with varying degrees of inflammation, hepatocellular injury, apoptosis and fibrosis. The most common mechanism for the development of NAFLD is insulin resistance. Insulin resistance is commonly associated with obesity, although it can develop in individuals who do not have obesity. A consequence of insulin resistance is increased peripheral lipolysis and increased delivery of free fatty acids to the liver. The concept of lipotoxicity emerged as the mechanisms by which fatty acids produce cell injury, promote apoptosis and activate inflammatory pathways were elucidated. While much work has been done mainly in cell culture models, the free fatty acid concentration in the liver is not significantly changed in NAFLD. Recently, the focus has shifted to alterations in other lipid metabolic pathways that appear to play an important role in the genesis of nonalcoholic steatohepatitis, the aggressive form of NAFLD. The innate immune system and the intestinal microbiota have been implicated in the development of NAFLD. These mechanisms are reviewed in this article.
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Affiliation(s)
- Arun J Sanyal
- Division of Gastroenterology, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, MCV Box 980342, Richmond, VA, 23298-0342, USA.
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Yin X, Guo Y, Li W, Huo E, Zhang Z, Nicolai J, Kleps RA, Hernando D, Katsaggelos AK, Omary RA, Larson AC. Chemical shift MR imaging methods for the quantification of transcatheter lipiodol delivery to the liver: preclinical feasibility studies in a rodent model. Radiology 2012; 263:714-22. [PMID: 22623693 DOI: 10.1148/radiol.12111916] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE To demonstrate the feasibility of using chemical shift magnetic resonance (MR) imaging fat-water separation methods for quantitative estimation of transcatheter lipiodol delivery to liver tissues. MATERIALS AND METHODS Studies were performed in accordance with institutional Animal Care and Use Committee guidelines. Proton nuclear MR spectroscopy was first performed to identify lipiodol spectral peaks and relative amplitudes. Next, phantoms were constructed with increasing lipiodol-water volume fractions. A multiecho chemical shift-based fat-water separation method was used to quantify lipiodol concentration within each phantom. Six rats served as controls; 18 rats underwent catheterization with digital subtraction angiography guidance for intraportal infusion of a 15%, 30%, or 50% by volume lipiodol-saline mixture. MR imaging measurements were used to quantify lipiodol delivery to each rat liver. Lipiodol concentration maps were reconstructed by using both single-peak and multipeak chemical shift models. Intraclass and Spearman correlation coefficients were calculated for statistical comparison of MR imaging-based lipiodol concentration and volume measurements to reference standards (known lipiodol phantom compositions and the infused lipiodol dose during rat studies). RESULTS Both single-peak and multipeak measurements were well correlated to phantom lipiodol concentrations (r(2) > 0.99). Lipiodol volume measurements were progressively and significantly higher when comparing between animals receiving different doses (P < .05 for each comparison). MR imaging-based lipiodol volume measurements strongly correlated with infused dose (intraclass correlation coefficients > 0.93, P < .001) with both single- and multipeak approaches. CONCLUSION Chemical shift MR imaging fat-water separation methods can be used for quantitative measurements of lipiodol delivery to liver tissues.
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Affiliation(s)
- Xiaoming Yin
- Department of Electrical Engineering and Computer Science and Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
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Non-alcoholic fatty liver disease impairs hippocampal-dependent memory in male rats. Physiol Behav 2012; 106:133-41. [PMID: 22280920 DOI: 10.1016/j.physbeh.2012.01.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 11/19/2011] [Accepted: 01/10/2012] [Indexed: 12/29/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a disorder observed in children and adults characterized by an accumulation of liver fat (>5% wet weight) in the absence of excessive alcohol intake. NAFLD affects 10 to 30% of the American population and is the most common cause of liver disease in the United States. NAFLD leads to serious disturbances in cardiovascular and hormonal function; however, possible effects on brain function have been overlooked. The aims of the present study were to test whether diet-induced NAFLD impairs hippocampal-dependent memory and to determine whether any observed deficits are associated with changes in hippocampal insulin signaling or concentrations of brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1). Post-weanling male Sprague-Dawley rats were fed a high fructose (60% of calories) or control diet for 12 weeks and then trained and tested in a spatial water maze. NAFLD was confirmed with postmortem measures of liver mass and liver lipid concentrations. NAFLD did not affect acquisition of the spatial water maze, but did impair retention tested 48 h later. Specifically, both groups demonstrated similar decreases in latency to swim to the escape platform over training trials, but on the memory test NAFLD rats took longer to reach the platform and made fewer visits to the platform location than control diet rats. There were no differences between the groups in terms of insulin-stimulated phosphorylation of insulin receptor β subunit (IR-β) and protein kinase B (PKB/AKT) in hippocampal slices or hippocampal BDNF or IGF-1 concentrations. Thus, these data indicate that NAFLD impairs hippocampal-dependent memory function and that the deficit does not appear attributable to alterations in hippocampal insulin signaling or hippocampal BDNF or IGF-1 concentrations.
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Sedlinsky C, Molinuevo MS, Cortizo AM, Tolosa MJ, Felice JI, Sbaraglini ML, Schurman L, McCarthy AD. Metformin prevents anti-osteogenic in vivo and ex vivo effects of rosiglitazone in rats. Eur J Pharmacol 2011; 668:477-85. [PMID: 21839072 DOI: 10.1016/j.ejphar.2011.07.033] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 06/30/2011] [Accepted: 07/24/2011] [Indexed: 02/08/2023]
Abstract
Long-term treatment with the insulin-sensitizer rosiglitazone reduces bone mass and increases fracture risk. We have recently shown that orally administered metformin stimulates bone reossification and increases the osteogenic potential of bone marrow progenitor cells (BMPC). In the present study we investigated the effect of a 2-week metformin and/or rosiglitazone treatment on bone repair, trabecular bone microarchitecture and BMPC osteogenic potential, in young male Sprague-Dawley rats. Compared to untreated controls, rosiglitazone monotherapy decreased bone regeneration, femoral metaphysis trabecular area, osteoblastic and osteocytic density, and TRAP activity associated with epiphyseal growth plates. It also decreased the ex vivo osteogenic commitment of BMPC, inducing an increase in PPARγ expression, and a decrease in Runx2/Cbfa1 expression, in AMP-kinase phosphorylation, and in osteoblastic differentiation and mineralization. After monotherapy with metformin, with the exception of PPARγ expression which was blunted, all of the above parameters were significantly increased (compared to untreated controls). Metformin/rosiglitazone co-treatment prevented all the in vivo and ex vivo anti-osteogenic effects of rosiglitazone monotherapy, with a reversion back to control levels of PPARγ, Runx2/Cbfa1 and AMP-kinase phosphorylation of BMPC. In vitro co-incubation of BMPC with metformin and compound C-an inhibitor of AMPK phosphorylation-abrogated the metformin-induced increase in type-1 collagen production, a marker of osteoblastic differentiation. In conclusion, in rodent models metformin not only induces direct osteogenic in vivo and ex vivo actions, but when it is administered orally in combination with rosiglitazone it can prevent several of the adverse effects that this thiazolidenedione shows on bone tissue.
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Affiliation(s)
- Claudia Sedlinsky
- GIOMM (Grupo de Investigación en Osteopatías y Metabolismo Mineral), Department of Biological Sciences, School of Exact Sciences, National University of La Plata, La Plata, Argentina
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Ogawa T, Fujii H, Yoshizato K, Kawada N. A human-type nonalcoholic steatohepatitis model with advanced fibrosis in rabbits. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:153-65. [PMID: 20489159 DOI: 10.2353/ajpath.2010.090895] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nonalcoholic steatohepatitis (NASH) progresses to liver fibrosis and cirrhosis, which can lead to life-threatening liver failure and the development of hepatocellular carcinoma. The aim of the present study was to create a rabbit model of NASH with advanced fibrosis (almost cirrhosis) by feeding the animals a diet supplemented with 0.75% cholesterol and 12% corn oil. After 9 months of feeding with this diet, the rabbits showed high total cholesterol levels in serum and liver tissues in the absence of insulin resistance. The livers became whitish and nodular. In addition, the number of rabbit macrophage antigen-positive cells and the expression of mRNAs for inflammatory cytokines showed a significant increase. Moreover, fibrotic septa composed of collagens and alpha-smooth muscle actin-positive cells were found between the central and portal veins, indicating alteration of the parenchymal architecture. There was also a marked increase of mRNAs for transforming growth factor-beta1 and collagen 1A1. Comprehensive analysis of protein and gene expression revealed an imbalance of the antioxidant system and methionine metabolism. We also found that ezetimibe attenuated steatohepatitis in this model. In conclusion, the present rabbit model of NASH features advanced fibrosis that is close to cirrhosis and may be useful for analyzing the molecular mechanisms of human NASH. Ezetimibe blunted the development of NASH in this model, suggesting its potential clinical usefulness for human steatohepatitis.
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Affiliation(s)
- Tomohiro Ogawa
- Department of Hepatology, Graduate School of Medicine, Osaka City University, 1-4-3, Asahimachi, Abeno, Osaka 545-8585, Japan
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Abstract
PURPOSE OF REVIEW This review focuses on recent advances in the study of the epidemiology, pathogenesis, natural history and treatment of nonalcoholic fatty liver disease (NAFLD). RECENT FINDINGS Study of hepatic lipid metabolism with respect to the contribution of de-novo lipogenesis to hepatic steatosis and insulin resistance and the dysregulation of cellular adaptive response to stress, that is, the unfolded protein response has added to our current understanding of NAFLD. microRNA has recently emerged and has been shown to be differentially expressed in patients with nonalcoholic steatohepatitis. Its mechanism of action remains to be further explored. There is no proven pharmacotherapy for the treatment of NAFLD. Lifestyle intervention to achieve weight loss and increase exercise is persistently associated with improved liver histology. The diagnostic utility of noninvasive markers and imaging modalities in assessing fibrosis remains to be elucidated. SUMMARY The underlying mechanism and pathogenesis of NAFLD remain elusive. Although research effort has advanced the understanding of the natural history, pathogenesis and management of the disease, there is no proven therapy for this medical condition. At present, treatment concentrates on managing underlying metabolic risk factors.
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