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Genetic association and epistatic interaction analysis of cluster of differentiation 14 and mannan-binding lectin 2 gene polymorphic variants in susceptibility to chronic periodontitis. Meta Gene 2021. [DOI: 10.1016/j.mgene.2021.100963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Kessoku T, Kobayashi T, Tanaka K, Yamamoto A, Takahashi K, Iwaki M, Ozaki A, Kasai Y, Nogami A, Honda Y, Ogawa Y, Kato S, Imajo K, Higurashi T, Hosono K, Yoneda M, Usuda H, Wada K, Saito S, Nakajima A. The Role of Leaky Gut in Nonalcoholic Fatty Liver Disease: A Novel Therapeutic Target. Int J Mol Sci 2021; 22:ijms22158161. [PMID: 34360923 PMCID: PMC8347478 DOI: 10.3390/ijms22158161] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 02/06/2023] Open
Abstract
The liver directly accepts blood from the gut and is, therefore, exposed to intestinal bacteria. Recent studies have demonstrated a relationship between gut bacteria and nonalcoholic fatty liver disease (NAFLD). Approximately 10–20% of NAFLD patients develop nonalcoholic steatohepatitis (NASH), and endotoxins produced by Gram-negative bacilli may be involved in NAFLD pathogenesis. NAFLD hyperendotoxicemia has intestinal and hepatic factors. The intestinal factors include impaired intestinal barrier function (leaky gut syndrome) and dysbiosis due to increased abundance of ethanol-producing bacteria, which can change endogenous alcohol concentrations. The hepatic factors include hyperleptinemia, which is associated with an excessive response to endotoxins, leading to intrahepatic inflammation and fibrosis. Clinically, the relationship between gut bacteria and NAFLD has been targeted in some randomized controlled trials of probiotics and other agents, but the results have been inconsistent. A recent randomized, placebo-controlled study explored the utility of lubiprostone, a treatment for constipation, in restoring intestinal barrier function and improving the outcomes of NAFLD patients, marking a new phase in the development of novel therapies targeting the intestinal barrier. This review summarizes recent data from studies in animal models and randomized clinical trials on the role of the gut–liver axis in NAFLD pathogenesis and progression.
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Affiliation(s)
- Takaomi Kessoku
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
- Department of Palliative Medicine, Yokohama City University Hospital, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
- Correspondence: ; Tel.: +81-45-787-2640; Fax: +81-45-784-3546
| | - Takashi Kobayashi
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Kosuke Tanaka
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
- Department of Palliative Medicine, Yokohama City University Hospital, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Atsushi Yamamoto
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Kota Takahashi
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Michihiro Iwaki
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
- Department of Palliative Medicine, Yokohama City University Hospital, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Anna Ozaki
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Yuki Kasai
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Asako Nogami
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Yasushi Honda
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
- Department of Palliative Medicine, Yokohama City University Hospital, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Yuji Ogawa
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Shingo Kato
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Kento Imajo
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Takuma Higurashi
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Kunihiro Hosono
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Masato Yoneda
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Haruki Usuda
- Department of Pharmacology, Shimane University Faculty of Medicine, 89-1 Enyacho, Izumo, Shimane 693-8501, Japan; (H.U.); (K.W.)
| | - Koichiro Wada
- Department of Pharmacology, Shimane University Faculty of Medicine, 89-1 Enyacho, Izumo, Shimane 693-8501, Japan; (H.U.); (K.W.)
| | - Satoru Saito
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
| | - Atsushi Nakajima
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (T.K.); (K.T.); (A.Y.); (K.T.); (M.I.); (A.O.); (Y.K.); (A.N.); (Y.H.); (Y.O.); (S.K.); (K.I.); (T.H.); (K.H.); (M.Y.); (S.S.); (A.N.)
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Kessoku T, Kobayashi T, Imajo K, Tanaka K, Yamamoto A, Takahashi K, Kasai Y, Ozaki A, Iwaki M, Nogami A, Honda Y, Ogawa Y, Kato S, Higurashi T, Hosono K, Yoneda M, Okamoto T, Usuda H, Wada K, Kobayashi N, Saito S, Nakajima A. Endotoxins and Non-Alcoholic Fatty Liver Disease. Front Endocrinol (Lausanne) 2021; 12:770986. [PMID: 34777261 PMCID: PMC8586459 DOI: 10.3389/fendo.2021.770986] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 10/18/2021] [Indexed: 01/18/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. It occurs with a prevalence of up to 25%, of which 10-20% cases progress to nonalcoholic steatohepatitis (NASH), cirrhosis, and liver cancer. The histopathology of NASH is characterized by neutrophilic infiltration, and endotoxins from gram-negative rods have been postulated as a contributing factor. Elevations in endotoxin levels in the blood can be classified as intestinal and hepatic factors. In recent years, leaky gut syndrome, which is characterized by impaired intestinal barrier function, has become a significant issue. A leaky gut may prompt intestinal bacteria dysbiosis and increase the amount of endotoxin that enters the liver from the portal vein. These contribute to persistent chronic inflammation and progressive liver damage. In addition, hepatic factors suggest that liver damage can be induced by low-dose endotoxins, which does not occur in healthy individuals. In particular, increased expression of CD14, an endotoxin co-receptor in the liver, may result in leptin-induced endotoxin hyper-responsiveness in obese individuals. Thus, elevated blood endotoxin levels contribute to the progression of NASH. The current therapeutic targets for NASH treat steatosis and liver inflammation and fibrosis. While many clinical trials are underway, no studies have been performed on therapeutic agents that target the intestinal barrier. Recently, a randomized placebo-controlled trial examined the role of the intestinal barrier in patients with NAFLD. To our knowledge, this study was the first of its kind and study suggested that the intestinal barrier may be a novel target in the future treatment of NAFLD.
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Affiliation(s)
- Takaomi Kessoku
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Palliative Medicine, Yokohama City University Hospital, Yokohama, Japan
- *Correspondence: Takaomi Kessoku,
| | - Takashi Kobayashi
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kento Imajo
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kosuke Tanaka
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Palliative Medicine, Yokohama City University Hospital, Yokohama, Japan
| | - Atsushi Yamamoto
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kota Takahashi
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yuki Kasai
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Anna Ozaki
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Michihiro Iwaki
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Palliative Medicine, Yokohama City University Hospital, Yokohama, Japan
| | - Asako Nogami
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yasushi Honda
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yuji Ogawa
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shingo Kato
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takuma Higurashi
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kunihiro Hosono
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Masato Yoneda
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takayuki Okamoto
- Department of Pharmacology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Haruki Usuda
- Department of Pharmacology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Koichiro Wada
- Department of Pharmacology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Noritoshi Kobayashi
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Oncology, Yokohama City University Hospital, Yokohama, Japan
| | - Satoru Saito
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Atsushi Nakajima
- Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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Kawabata K, Kanmura S, Morinaga Y, Tanaka A, Makino T, Fujita T, Arima S, Sasaki F, Nasu Y, Tanoue S, Hashimoto S, Ido A. A high‑fructose diet induces epithelial barrier dysfunction and exacerbates the severity of dextran sulfate sodium‑induced colitis. Int J Mol Med 2018; 43:1487-1496. [PMID: 30628636 DOI: 10.3892/ijmm.2018.4040] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/19/2018] [Indexed: 11/06/2022] Open
Abstract
Excessive fructose intake is a risk factor for gut symptoms in patients with inflammatory bowel disease, however, its effect on the intestinal tract has not been evaluated previously. The present study investigated the impact of a high‑fructose diet (HFD) on intestinal barrier function in mice with experimental colitis. C57/BL6 mice were provided with either a HFD or control diet and either plain drinking water or water containing 1% dextran sulfate sodium (DSS) for 2 weeks. The disease activity index (DAI), pathological scores and expression of inflammatory cytokines were compared among the groups, and the proportions of fecal bacteria in the colon were analyzed. The body weight and colon length were significantly decreased, and the DAI and pathological scores were significantly increased in the DSS/HFD‑treated mice compared with the non‑DSS‑treated and control diet mice. Regarding the expression of inflammatory cytokines, the levels of interleukin (IL)‑6, IL‑1β and tumor necrosis factor‑α were significantly increased, and the expression of the tight junction protein occludin was significantly decreased in the DSS/HFD‑treated mice. The total bacterial count was increased in the HFD mice. Taken together, these results indicate that an HFD resulted in the deterioration of intestinal barrier function and increased susceptibility to DSS‑induced colitis.
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Affiliation(s)
- Katsuto Kawabata
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Shuji Kanmura
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Yuko Morinaga
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Akihito Tanaka
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Tomoaki Makino
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Toshihiro Fujita
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Shiho Arima
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Fumisato Sasaki
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Yuichirou Nasu
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Shiroh Tanoue
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Shinichi Hashimoto
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
| | - Akio Ido
- Digestive and Lifestyle Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890‑8544, Japan
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Chapman RW, Williamson KD. Are Dominant Strictures in Primary Sclerosing Cholangitis a Risk Factor for Cholangiocarcinoma? ACTA ACUST UNITED AC 2017; 16:124-129. [PMID: 28706774 PMCID: PMC5486581 DOI: 10.1007/s11901-017-0341-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW Cholangiocarcinoma is a devastating, unpredictable complication of large duct primary sclerosing cholangitis (PSC), which occurs in 5-15% of patients. The aim of this review is to discuss whether dominant strictures (DS) occurring in the larger bile ducts in PSC are a risk factor for the development of cholangiocarcinoma. RECENT FINDINGS The development of DS is related to specific genetic polymorphisms affecting the innate immune system and the microbiome. In a recent study, the mean survival of PSC patients with DS was much worse (13.7 years) than for those without a DS (23 years). Survival difference was related to a 26% risk of cholangiocarcinoma, which developed only in those with DS. Half of the patients with cholangiocarcinoma presented within 4 months of the diagnosis of PSC. In another study, the risk of developing cholangiocarcinoma was directly related to the presence of underlying IBD, although this remains controversial. Efforts are being made towards surveying for cholangiocarcinoma including magnetic resonance imaging, endoscopic surveillance and serum tumour markers, but so far, an effective surveillance strategy has not been identified. DS should be treated endoscopically in the setting of symptoms, and there is limited evidence to suggest this may impact protectively on progression to cholangiocarcinoma. SUMMARY It is established that the presence of symptomatic DS occurring in the larger bile ducts in PSC can be the first presentation of cholangiocarcinoma. There is an increasing body of evidence that even when proven to be benign, dominant biliary strictures predispose to the future development of cholangiocarcinoma. Regular surveillance should be targeted at this selected high-risk group of PSC patients.
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Affiliation(s)
- Roger W Chapman
- Nuffield Department of Medicine, Oxford University, Oxford, UK.,Translational Gastroenterology Unit, Oxford University Hospital, Oxford, UK.,Translational Gastroenterology Unit, John Radcliffe Hospital, Headley Way, Headington, Oxford, OX3 9DU UK
| | - Kate D Williamson
- Nuffield Department of Medicine, Oxford University, Oxford, UK.,Translational Gastroenterology Unit, Oxford University Hospital, Oxford, UK
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Kapil S, Duseja A, Sharma BK, Singla B, Chakraborti A, Das A, Ray P, Dhiman RK, Chawla Y. Genetic polymorphism in CD14 gene, a co-receptor of TLR4 associated with non-alcoholic fatty liver disease. World J Gastroenterol 2016; 22:9346-9355. [PMID: 27895422 PMCID: PMC5107698 DOI: 10.3748/wjg.v22.i42.9346] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 08/03/2016] [Accepted: 09/14/2016] [Indexed: 02/06/2023] Open
Abstract
AIM To evaluate the pathogenic role of toll-like receptor (TLR) gene polymorphisms in patients with non-alcoholic fatty liver disease (NAFLD).
METHODS Two hundred and fifty subjects (NAFLD = 200, healthy volunteers = 50) underwent polymerase chain reaction and restriction fragment length polymorphism to assess one polymorphism in the toll-like receptor 2 (TLR2) gene (A753G), two polymorphisms in the TLR4 gene (TLR4 Asp299Gly and Thr399Ile allele), and two polymorphisms in the cluster of differentiation 14 (CD14) (C-159T and C-550T) gene, a co-receptor of TLR4. Association of TLR gene polymorphisms with NAFLD and its severity was evaluated by genetic models of association.
RESULTS On both multiplicative and recessive models of gene polymorphism association, there was significant association of CD14 C (-159) T polymorphism with NAFLD; patients with TT genotype had a 2.6 fold increased risk of developing NAFLD in comparison to CC genotype. There was no association of TLR2 Arg753Gln, TLR4 Asp299Gly, Thr399Ile, and CD14 C (-550) T polymorphisms with NAFLD. None of the TLR gene polymorphisms had an association with histological severity of NAFLD.
CONCLUSION Patients with CD14 C (-159) T gene polymorphism, a co-receptor of TLR4, have an increased risk of NAFLD development.
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Friedrich K, Smit M, Brune M, Giese T, Rupp C, Wannhoff A, Kloeters P, Leopold Y, Denk GU, Weiss KH, Stremmel W, Sauer P, Hohenester S, Schirmacher P, Schemmer P, Gotthardt DN. CD14 is associated with biliary stricture formation. Hepatology 2016; 64:843-52. [PMID: 26970220 DOI: 10.1002/hep.28543] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 02/23/2016] [Accepted: 03/09/2016] [Indexed: 12/14/2022]
Abstract
UNLABELLED The pathogenesis of intrahepatic biliary stricture formation in patients with primary sclerosing cholangitis (PSC) or after liver transplantation (LTx) remains elusive. CD14 receptor signaling is a key mediator of the innate immune system; its common genetic variant is associated with alcoholic liver disease. PSC and LTx cohort patients and primary biliary cirrhosis (PBC) control patients were genotyped for the CD14 -260C>T (rs2569190) polymorphism, and genotypes were correlated with long-term clinical outcome. Biliary tissue, bile, and whole blood of PSC patients and healthy controls were screened for markers of the innate immune system and bacterial infection. In 121 PSC patients, the CD14 -260C>T genotype was associated with development of dominant bile duct strictures (P = 0.02). In 365 LTx patients, TT carriers (4.1%) were protected against the formation of nonanastomotic biliary strictures versus CC/CT patients (12.6%; P = 0.01). Chemokine ligand 8 (P = 0.04) and chemokine receptor 6 (P = 0.004) were up-regulated in biliary tissue of PSC patients with the TT versus the CC/CT genotype. Lipopolysaccharide whole-blood stimulation resulted in a significant change in interleukin (IL)-8 (P = 0.05) and IL-12p40 levels (P = 0.04) in healthy control subjects carrying the TT genotype. TT PSC patients were protected against Gram-negative bacterial biliary infection (TT: 0% vs. CC/CT 22.5%; P = 0.02). Serum-soluble CD14 levels correlated with the CD14 -260C>T genotype (P = 0.02), representing an independent risk indicator of survival in PSC patients (hazard ratio, 0.40; 95% confidence interval, 0.19-0.86; P =0.01). CONCLUSIONS The function of the innate immune response by CD14 is crucial during biliary infection and stricture formation. The benefits of CD14 signaling modification should be addressed in future studies. (Hepatology 2016;64:843-852).
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Affiliation(s)
- Kilian Friedrich
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
| | - Mark Smit
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
| | - Maik Brune
- Department of Internal Medicine I, University Hospital of Heidelberg, Heidelberg, Germany
| | - Thomas Giese
- Heidelberg University Hospital, Institute for Immunology, Heidelberg, Germany
| | - Christian Rupp
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
| | - Andreas Wannhoff
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
| | - Petra Kloeters
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
| | - Yvonne Leopold
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
| | - Gerald Ulrich Denk
- Liver Center Munich, Department of Medicine II, University of Munich (LMU), Munich, Germany.,Transplantation Center, University of Munich, Munich, Germany
| | - Karl Heinz Weiss
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
| | - Peter Sauer
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
| | - Simon Hohenester
- Liver Center Munich, Department of Medicine II, University of Munich (LMU), Munich, Germany
| | - Peter Schirmacher
- Heidelberg University Hospital, Institute for Pathology, Heidelberg, Germany
| | - Peter Schemmer
- Department of General, Visceral and Transplant Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Daniel Nils Gotthardt
- Department of Internal Medicine IV, University Hospital of Heidelberg, Heidelberg, Germany
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8
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Resveratrol ameliorates fibrosis and inflammation in a mouse model of nonalcoholic steatohepatitis. Sci Rep 2016; 6:22251. [PMID: 26911834 PMCID: PMC4766502 DOI: 10.1038/srep22251] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 02/10/2016] [Indexed: 12/11/2022] Open
Abstract
The natural polyphenol compound resveratrol (RSV) is considered to have a broad spectrum of beneficial biological activities upon human health. However, the exact effect of RSV on steatosis (a phenotype of non-alcoholic fatty liver [NAFL]) or fibrosis and inflammation (major phenotypes of non-alcoholic steatohepatitis [NASH]) is not known. Our data showed that administration of RSV (2 or 20 mg/kg/day) did not suppress steatosis in a high-fat diet-induced model of NAFL in mice. In contrast, identical concentrations of RSV dramatically inhibited inflammation and fibrosis in a low-dose lipopolysaccharide-induced model of NASH. These data suggested that RSV administration-mediated improvement of inflammation and fibrosis was due to the inhibition of LPS reactivity controlled by CD14 expression in Kupffer cells. These findings suggest that RSV could be a candidate agent for the treatment of NASH.
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9
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Abstract
Along with the obesity epidemic, the prevalence of nonalcoholic fatty liver disease (NAFLD) has increased exponentially. The histological disease spectrum of NAFLD ranges from bland fatty liver (hepatic steatosis), to the concomitant presence of inflammation and ballooning which defines nonalcoholic steatohepatitis (NASH). The latter can progress in a subset to fibrosis, leading ultimately to cirrhosis and hepatocellular carcinoma. The past decade has seen tremendous advances in our understanding of the genetic and epigenetic bases of NAFLD, mainly through the application of high end technology platforms including genome-wide association studies (GWAS). These have helped to define common gene variants (minor allele frequency >5 %) that contribute to the NAFLD phenotype. Looking to the future, these discoveries are expected to lead to improved diagnostics, the personalization of medicine, and a better understanding of the pathophysiological underpinnings that drive the transition from NAFLD to steatohepatitis and fibrosis, leading to the identification of novel therapeutic targets. In this review, we summarize data on the current state of knowledge with regard to the genetic and epigenetic mechanisms for the development of NASH.
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Wood KL, Miller MH, Dillon JF. Systematic review of genetic association studies involving histologically confirmed non-alcoholic fatty liver disease. BMJ Open Gastroenterol 2015; 2:e000019. [PMID: 26462272 PMCID: PMC4599155 DOI: 10.1136/bmjgast-2014-000019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/21/2015] [Accepted: 01/23/2015] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease has an increasing prevalence in Western countries, affecting up to 20% of the population.
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Affiliation(s)
| | - Michael H Miller
- Medical Research Institute, University of Dundee, Ninewells Hospital , Dundee , UK
| | - John F Dillon
- Medical Research Institute, University of Dundee, Ninewells Hospital , Dundee , UK
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11
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Sipeki N, Antal-Szalmas P, Lakatos PL, Papp M. Immune dysfunction in cirrhosis. World J Gastroenterol 2014; 20:2564-2577. [PMID: 24627592 PMCID: PMC3949265 DOI: 10.3748/wjg.v20.i10.2564] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/25/2013] [Accepted: 01/20/2014] [Indexed: 02/06/2023] Open
Abstract
Innate and adaptive immune dysfunction, also referred to as cirrhosis-associated immune dysfunction syndrome, is a major component of cirrhosis, and plays a pivotal role in the pathogenesis of both the acute and chronic worsening of liver function. During the evolution of the disease, acute decompensation events associated with organ failure(s), so-called acute-on chronic liver failure, and chronic decompensation with progression of liver fibrosis and also development of disease specific complications, comprise distinct clinical entities with different immunopathology mechanisms. Enhanced bacterial translocation associated with systemic endotoxemia and increased occurrence of systemic bacterial infections have substantial impacts on both clinical situations. Acute and chronic exposure to bacteria and/or their products, however, can result in variable clinical consequences. The immune status of patients is not constant during the illness; consequently, alterations of the balance between pro- and anti-inflammatory processes result in very different dynamic courses. In this review we give a detailed overview of acquired immune dysfunction and its consequences for cirrhosis. We demonstrate the substantial influence of inherited innate immune dysfunction on acute and chronic inflammatory processes in cirrhosis caused by the pre-existing acquired immune dysfunction with limited compensatory mechanisms. Moreover, we highlight the current facts and future perspectives of how the assessment of immune dysfunction can assist clinicians in everyday practical decision-making when establishing treatment and care strategies for the patients with end-stage liver disease. Early and efficient recognition of inappropriate performance of the immune system is essential for overcoming complications, delaying progression and reducing mortality.
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12
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Abstract
There are trillions of microorganisms in the human intestine collectively called gut microbiota. Obesity may be affected by the gut microbiota through energy harvesting and fat storage by the bacteria. Small intestinal bacterial overgrowth is also responsible for endotoxemia, systemic inflammation, and its consequences including obesity and nonalcoholic fatty liver disease (NAFLD). Relationship between gut microbiota and NAFLD is also dependent on altered choline and bile acid metabolism and endogenous alcohol production by gut bacteria. Further evidence linking gut microbiota with obesity and NAFLD comes from studies showing usefulness of probiotics in animals and patients with NAFLD. This article reviews the relationship among gut microbiota, obesity, and NAFLD.
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Affiliation(s)
- Ajay Duseja
- Department of Hepatology, Post Graduate Institute of Medical Education and Research, Sector 12, Chandigarh 160012, India
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13
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Microbiota and nonalcoholic steatohepatitis. Semin Immunopathol 2013; 36:115-32. [PMID: 24337650 DOI: 10.1007/s00281-013-0404-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Accepted: 10/15/2013] [Indexed: 02/07/2023]
Abstract
The recent rise in obesity-related diseases, such as nonalcoholic fatty liver disease and its strong association with microbiota, has elicited interest in the underlying mechanisms of these pathologies. Experimental models have highlighted several mechanisms connecting microbiota to the development of liver dysfunction in nonalcoholic steatohepatitis (NASH) such as increased energy harvesting from the diet, small intestine bacterial overgrowth, modulation of the intestinal barrier by glucagon-like peptide-2 secretions, activation of innate immunity through the lipopolysaccharide-CD14 axis caused by obesity-induced leptin, periodontitis, and sterile inflammation. The manipulation of microbiota through probiotics, prebiotics, antibiotics, and periodontitis treatment yields encouraging results for the treatment of obesity, diabetes, and NASH, but data in humans is scarce.
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14
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Satoh D, Yagi T, Nagasaka T, Shinoura S, Umeda Y, Yoshida R, Utsumi M, Tanaka T, Sadamori H, Fujiwara T. CD14 upregulation as a distinct feature of non-alcoholic fatty liver disease after pancreatoduodenectomy. World J Hepatol 2013; 5:189-95. [PMID: 23671723 PMCID: PMC3648650 DOI: 10.4254/wjh.v5.i4.189] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 10/20/2012] [Accepted: 11/25/2012] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the pathogenesis of non-alcoholic fatty liver disease (NAFLD) after pancreatoduodenectomy (PD). METHODS A cohort of 82 patients who underwent PD at Okayama University Hospital between 2003 and 2009 was enrolled and the clinicopathological features were compared between patients with and without NAFLD after PD. Computed tomography (CT) images were evaluated every 6 mo after PD for follow-up. Hepatic steatosis was diagnosed on CT when hepatic attenuation values were 40 Hounsfield units. Liver biopsy was performed for 4 of 30 patients with NAFLD after PD who consented to undergo biopsies. To compare NAFLD after PD with NAFLD associated with metabolic syndrome, liver samples were obtained from 10 patients with NAFLD associated with metabolic syndrome [fatty liver, n = 5; non-alcoholic steatohepatitis (NASH), n = 5] by percutaneous ultrasonography-guided liver biopsy. Double-fluorescence immunohistochemistry was applied to examine CD14 expression as a marker of lipopolysaccharide (LPS)-sensitized macrophage cells (Kupffer cells) in liver biopsy specimens. RESULTS The incidence of postoperative NAFLD was 36.6% (30/82). Univariate analysis identified cancer of the pancreatic head, sex, diameter of the main pancreatic duct, and dissection of the nerve plexus as factors associated with the development of NAFLD after PD. Those patients who developed NAFLD after PD demonstrated significantly decreased levels of serum albumin, total protein, cholesterol and triglycerides compared to patients without NAFLD after PD, but no glucose intolerance or insulin resistance. Liver biopsy was performed in four patients with NAFLD after PD. All four patients showed moderate-to-severe steatosis and NASH was diagnosed in two. Numbers of cells positive for CD68 (a marker of Kupffer cells) and CD14 (a marker of LPS-sensitized Kupffer cells) were counted in all biopsy specimens. The number of CD68+ cells in specimens of NAFLD after PD was significantly increased from that in specimens of NAFLD associated with metabolic syndrome specimens, which indicated the presence of significantly more Kupffer cells in NAFLD after PD than in NAFLD associated with metabolic syndrome. Similarly, more CD14+ cells, namely, LPS-sensitized Kupffer cells, were observed in NAFLD after PD than in NAFLD associated with metabolic syndrome. Regarding NASH, more CD68+ cells and CD14+ cells were observed in NASH after PD specimens than in NASH associated with metabolic syndrome. This showed that more Kupffer cells and more LPS-sensitized Kupffer cells were present in NASH after PD than in NASH associated with metabolic syndrome. These observations suggest that after PD, Kupffer cells and LPS-sensitized Kupffer cells were significantly upregulated, not only in NASH, but also in simple fatty liver. CONCLUSION NAFLD after PD is characterized by both malnutrition and the up-regulation of CD14 on Kupffer cells. Gut-derived endotoxin appears central to the development of NAFLD after PD.
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Affiliation(s)
- Daisuke Satoh
- Daisuke Satoh, Takahito Yagi, Takeshi Nagasaka, Susumu Shinoura, Yuzo Umeda, Ryuichi Yoshida, Masashi Utsumi, Hiroshi Sadamori, Toshiyoshi Fujiwara, Department of Gastroenterological Surgery, Transplant, and Surgical Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
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15
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Yilmaz Y. Review article: is non-alcoholic fatty liver disease a spectrum, or are steatosis and non-alcoholic steatohepatitis distinct conditions? Aliment Pharmacol Ther 2012; 36:815-23. [PMID: 22966992 DOI: 10.1111/apt.12046] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 08/17/2012] [Accepted: 08/22/2012] [Indexed: 12/12/2022]
Abstract
BACKGROUND Non-alcoholic fatty liver disease (NAFLD) is currently conceptualised as a clinical spectrum that results from a ‘multiple-hit’ process which begins with simple steatosis and subsequently renders the hepatocytes susceptible to a variety of insults. Ultimately, more serious liver injuries like non-alcoholic steatohepatitis (NASH) and cirrhosis may develop. Although the metabolic syndrome is considered the crucial player in the pathogenesis of NAFLD, recent studies have highlighted novel pathophysiological mechanisms in this clinical entity. AIM To discuss the pathophysiology of NAFLD based on the hypothesis that simple steatosis and NASH are discrete entities rather than two points on a spectrum. METHODS A literature search was conducted in August 2012 on PubMed, Ovid Embase, Ovid Medline and Scopus using the following search terms: steatosis, non-alcoholic steatohepatitis, pathophysiology, fatty liver, natural history and genetics. RESULTS Simple steatosis and NASH appear as two distinct pathophysiological entities and progression from pure fatty liver to NASH appears to be so rare as to warrant publication. The possible pathogenetic pathways specifically related to NASH are highlighted. CONCLUSIONS Although simple steatosis and non-alcoholic steatohepatitis are currently viewed as two histological subtypes of the unique spectrum of non-alcoholic fatty liver disease, the two conditions are likely distinct not only from a histological but also from a pathophysiological standpoint. Efforts to distinguish simple steatosis from non-alcoholic steatohepatitis using non-invasive modalities should be informed by the current pathophysiology of these two clinical entities.
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Affiliation(s)
- Y Yilmaz
- Institute of Gastroenterology, Marmara University, Maltepe, Istanbul, Turkey.
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16
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Imajo K, Fujita K, Yoneda M, Nozaki Y, Ogawa Y, Shinohara Y, Kato S, Mawatari H, Shibata W, Kitani H, Ikejima K, Kirikoshi H, Nakajima N, Saito S, Maeyama S, Watanabe S, Wada K, Nakajima A. Hyperresponsivity to low-dose endotoxin during progression to nonalcoholic steatohepatitis is regulated by leptin-mediated signaling. Cell Metab 2012; 16:44-54. [PMID: 22768838 DOI: 10.1016/j.cmet.2012.05.012] [Citation(s) in RCA: 249] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 03/22/2012] [Accepted: 05/23/2012] [Indexed: 02/07/2023]
Abstract
Although bacterial endotoxin, such as lipopolysaccharide (LPS), plays a key role in the pathogenesis of nonalcoholic steatohepatitis (NASH), detailed mechanisms of this pathogenesis remain unclear. Here, we demonstrate that upregulation of CD14 by leptin-mediated signaling is critical to hyperreactivity against endotoxin during NASH progression. Upregulation of CD14 in Kupffer cells and hyperreactivity against low-dose LPS were observed in high-fat diet (HFD)-induced steatosis mice, but not chow-fed-control mice. Hyperresponsivity against low-dose LPS led to accelerated NASH progression, including liver inflammation and fibrosis. Administering leptin in chow-fed mice caused increased hepatic expression of CD14 via STAT3 signaling, resulting in hyperreactivity against low-dose LPS without steatosis. In contrast, a marked decrease in hepatic CD14 expression was observed in leptin-deficient ob/ob mice, despite severe steatosis. Our results indicate that obesity-induced leptin plays a crucial role in NASH progression via enhanced responsivity to endotoxin, and we propose a mechanism of bacteria-mediated progression of NASH.
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Affiliation(s)
- Kento Imajo
- Department of Gastroenterology, Yokohama City University Graduate School of Medicine, 3-9 Fuku-ura, Yokohama, Japan
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17
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Gäbele E, Dostert K, Hofmann C, Wiest R, Schölmerich J, Hellerbrand C, Obermeier F. DSS induced colitis increases portal LPS levels and enhances hepatic inflammation and fibrogenesis in experimental NASH. J Hepatol 2011; 55:1391-9. [PMID: 21703208 DOI: 10.1016/j.jhep.2011.02.035] [Citation(s) in RCA: 216] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Revised: 02/20/2011] [Accepted: 02/22/2011] [Indexed: 12/21/2022]
Abstract
BACKGROUND & AIMS Intestinal bacterial overgrowth and increased permeability are features of non alcoholic steatohepatitis (NASH). Bacterial endotoxin has been shown to promote NASH progression. Application of dextran sulfate sodium (DSS) is a colitis model in mice characterized by damage of the intestinal barrier. This study was designed to investigate if application of DSS aggravates experimental NASH. METHODS Male C57bl/6 mice were allocated into four experimental groups receiving either (I) standard chow (SC), (II) a high fat (HF) diet, (III) SC+DSS (1% in the drinking water), and (IV) HF+DSS for 12 weeks. RESULTS DSS treatment caused inflammation and proinflammatory gene expression (IL-1β, IL-17, TNF) in the colon. Expression of colonic antimicrobial peptide Cramp was significantly induced in SC+DSS mice, whereas expression was blocked in the HF+DSS group. Endotoxin levels were elevated in SC+DSS and HF mice but further augmented in the HF+DSS group. In line with this, increased hepatic TLR4 and TLR9 mRNA levels were detected in HF+DSS mice. The histological analysis revealed hepatic steatosis in both HF groups. Hepatic inflammation was more severe in HF+DSS mice, reflected by histology and analysis of proinflammatory gene expression (TNF and MCP-1). HF+DSS mice showed increased hepatic fibrosis by sirius red staining, hepatic collagen I expression, and α-SMA positive cells accompanied by higher p47(phox), TIMP-1, TGF-β, Pai-1, and α-SMA mRNA expression. CONCLUSIONS Induction of an intestinal inflammation in experimental NASH promotes LPS translocation, hepatic inflammation, and fibrogenesis probably due to inhibition of intestinal antimicrobial peptides. These findings underscore the pathophysiological role of the gut-liver axis in the progression of NASH.
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Affiliation(s)
- Erwin Gäbele
- Department of Internal Medicine I, University Medical Center Regensburg, Germany.
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18
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Hernaez R. Genetic factors associated with the presence and progression of nonalcoholic fatty liver disease: a narrative review. GASTROENTEROLOGIA Y HEPATOLOGIA 2011; 35:32-41. [PMID: 22093607 DOI: 10.1016/j.gastrohep.2011.08.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 08/04/2011] [Indexed: 12/25/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world. Whereas insulin resistance and obesity are considered major risk factors for the development and progression of NAFLD, the genetic underpinnings are unclear. Before 2008, candidate gene studies based on prior knowledge of pathophysiology of fatty liver yielded conflicting results. In 2008, Romeo et al. published the first genome wide association study and reported the strongest genetic signal for the presence of fatty liver (PNPLA3, patatin-like phospholipase domain containing 3; rs738409). Since then, two additional genome wide scans were published and identified 9 additional genetic variants. Whereas these results shed light into the understanding of the genetics of NAFLD, most of associations have not been replicated in independent samples and, therefore, remain undetermined the significance of these findings. This review aims to summarize the understanding of genetic epidemiology of NAFLD and highlights the gaps in knowledge.
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Affiliation(s)
- Ruben Hernaez
- Department of Medicine, The Johns Hopkins School of Medicine, Baltimore, MD 21287, USA.
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19
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20
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Lin YC, Chang PF, Hu FC, Yang WS, Chang MH, Ni YH. A common variant in the PNPLA3 gene is a risk factor for non-alcoholic fatty liver disease in obese Taiwanese children. J Pediatr 2011; 158:740-4. [PMID: 21168155 DOI: 10.1016/j.jpeds.2010.11.016] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 09/07/2010] [Accepted: 11/02/2010] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To test the hypothesis that the presence of the PNPLA3 rs738409 G allele would increase the susceptibility of non-alcoholic fatty liver disease (NAFLD) in obese Taiwanese children. STUDY DESIGN A total of 520 obese children aged 6-18 years were recruited. Their PNPLA3 rs738409 genotypes-CC, CG, or GG-were detected by the 5'-nuclease assay. The effects of the PNPLA3 rs738409 G allele on pediatric NAFLD were evaluated based on liver ultrasonography findings and mean serum alanine aminotransferase levels in these children. RESULTS NAFLD was present in 19.6% of the obese children. In comparison to the subjects with CC alleles, the risk of NAFLD was increased by 2.96-fold (95% CI, 1.57 to 5.59, P = .0008) in the subjects with CG alleles and by 5.84-fold (95% CI, 2.59 to 13.16; P < .0001) in those with GG alleles. Variant PNPLA3 rs738409 genotypes were associated with increases in mean serum alanine aminotransferase level of 4.77 IU/L (P = .0435) in subjects with CG alleles and of 10.86 IU/L (P < .0001) in those with GG alleles compared with subjects with CC alleles. CONCLUSIONS The variant PNPLA3 rs738409 genotypes increased the risk of NAFLD in our population of obese Taiwanese children. The effect of the G allele on pediatric NAFLD followed a dominant genetic model.
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Affiliation(s)
- Yu-Cheng Lin
- Department of Pediatrics, Far Eastern Memorial Hospital, Banqiao City, Taipei County, Taiwan
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21
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Harte AL, da Silva NF, Creely SJ, McGee KC, Billyard T, Youssef-Elabd EM, Tripathi G, Ashour E, Abdalla MS, Sharada HM, Amin AI, Burt AD, Kumar S, Day CP, McTernan PG. Elevated endotoxin levels in non-alcoholic fatty liver disease. JOURNAL OF INFLAMMATION-LONDON 2010; 7:15. [PMID: 20353583 PMCID: PMC2873499 DOI: 10.1186/1476-9255-7-15] [Citation(s) in RCA: 270] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 03/30/2010] [Indexed: 12/24/2022]
Abstract
Background Emerging data indicate that gut-derived endotoxin may contribute to low-grade systemic inflammation in insulin resistant states. This study aimed to examine the importance of serum endotoxin and inflammatory markers in non-alcoholic fatty liver disease (NAFLD) patients, with and without type 2 diabetes mellitus (T2DM), and to explore the effect of treatment with a lipase inhibitor, Orlistat, on their inflammatory status. Methods Fasted serum from 155 patients with biopsy proven NAFLD and 23 control subjects were analysed for endotoxin, soluble CD14 (sCD14), soluble tumour necrosis factor receptor II (sTNFRII) and various metabolic parameters. A subgroup of NAFLD patients were re-assessed 6 and 12 months after treatment with diet alone (n = 6) or diet plus Orlistat (n = 8). Results Endotoxin levels were significantly higher in patients with NAFLD compared with controls (NAFLD: 10.6(7.8, 14.8) EU/mL; controls: 3.9(3.2, 5.2) EU/mL, p < 0.001); NAFLD alone produced comparable endotoxin levels to T2DM (NAFLD: T2DM: 10.6(5.6, 14.2) EU/mL; non-diabetic: 10.6(8.5, 15.2) EU/mL), whilst a significant correlation between insulin resistance and serum endotoxin was observed (r = 0.27, p = 0.008). Both sCD14 (p < 0.01) and sTNFRII (p < 0.001) increased with severity of fibrosis. A positive correlation was also noted between sTNFRII and sCD14 in the NAFLD subjects (r = 0.29, p = 0.004). Sub-cohort treatment with Orlistat in patients with NAFLD showed significant decreases in ALT (p = 0.006), weight (p = 0.005) and endotoxin (p = 0.004) compared with the NAFLD, non-Orlistat treated control cohort at 6 and 12 months post therapy, respectively. Conclusions Endotoxin levels were considerably increased in NAFLD patients, with marked increases noted in early stage fibrosis compared with controls. These results suggest elevated endotoxin may serve as an early indicator of potential liver damage, perhaps negating the need for invasive liver biopsy. As endotoxin may promote insulin resistance and inflammation, interventions aimed at reducing endotoxin levels in NAFLD patients may prove beneficial in reducing inflammatory burden.
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Affiliation(s)
- Alison L Harte
- University of Warwick, Unit for Diabetes and Metabolism, Warwick Medical School, Clinical Sciences Research Institute, UHCW, Clifford Bridge Road, Coventry, CV2 2DX, UK
| | - Nancy F da Silva
- University of Warwick, Unit for Diabetes and Metabolism, Warwick Medical School, Clinical Sciences Research Institute, UHCW, Clifford Bridge Road, Coventry, CV2 2DX, UK
| | - Steven J Creely
- University of Warwick, Unit for Diabetes and Metabolism, Warwick Medical School, Clinical Sciences Research Institute, UHCW, Clifford Bridge Road, Coventry, CV2 2DX, UK
| | - Kirsty C McGee
- University of Warwick, Unit for Diabetes and Metabolism, Warwick Medical School, Clinical Sciences Research Institute, UHCW, Clifford Bridge Road, Coventry, CV2 2DX, UK
| | - Thomas Billyard
- University of Warwick, Unit for Diabetes and Metabolism, Warwick Medical School, Clinical Sciences Research Institute, UHCW, Clifford Bridge Road, Coventry, CV2 2DX, UK
| | | | - Gyanendra Tripathi
- University of Warwick, Unit for Diabetes and Metabolism, Warwick Medical School, Clinical Sciences Research Institute, UHCW, Clifford Bridge Road, Coventry, CV2 2DX, UK
| | - Esmat Ashour
- Biochemistry Dept, National Research Center, Dokki, Giza, Egypt
| | - Mohga S Abdalla
- Chemistry Dept, Faculty of Science, Helwan University, Egypt
| | - Hayat M Sharada
- Chemistry Dept, Faculty of Science, Helwan University, Egypt
| | - Ashraf I Amin
- Clinical Pathology Dept, National Institute of Diabetes & Endocrinology, Cairo, Egypt
| | - Alastair D Burt
- School of Clinical Medicine (Hepatology), Floor 4, William Leech Building, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Sudhesh Kumar
- University of Warwick, Unit for Diabetes and Metabolism, Warwick Medical School, Clinical Sciences Research Institute, UHCW, Clifford Bridge Road, Coventry, CV2 2DX, UK
| | - Christopher P Day
- School of Clinical Medicine (Hepatology), Floor 4, William Leech Building, The Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Philip G McTernan
- University of Warwick, Unit for Diabetes and Metabolism, Warwick Medical School, Clinical Sciences Research Institute, UHCW, Clifford Bridge Road, Coventry, CV2 2DX, UK
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22
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Kudo H, Takahara T, Yata Y, Kawai K, Zhang W, Sugiyama T. Lipopolysaccharide triggered TNF-alpha-induced hepatocyte apoptosis in a murine non-alcoholic steatohepatitis model. J Hepatol 2009; 51:168-75. [PMID: 19446916 DOI: 10.1016/j.jhep.2009.02.032] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 02/07/2009] [Accepted: 02/09/2009] [Indexed: 01/18/2023]
Abstract
BACKGROUND/AIMS Endogenous gut-derived bacterial endotoxins have been implicated as an important cofactor in the pathogenesis of liver injury, although their contribution to the progression of non-alcoholic steatohepatitis (NASH) remains unclear. METHODS Male C57BL/6 mice were fed a methionine-choline-deficient (MCD) diet or a standard diet for 17 days, following which they were injected with lipopolysaccharide (LPS) intraperitoneally and sacrificed after 6h. In an in vitro experiment, RAW264.7 cells, a mouse macrophage cell line, and primary mouse hepatocytes were co-treated with hydrogen peroxide (H(2)O(2)) and LPS or tumour necrosis factor (TNF)-alpha. RESULTS Compared to the control mice, LPS treatment significantly increased hepatic TNF-alpha production in MCD mice. LPS also significantly increased TUNEL-positive cells, which were especially observed in the perivenular area. The apoptotic change was inhibited by co-treatment with a neutralizing anti-mouse TNF receptor antibody or pentoxifylline. In an in vitro experiment, treatment with H(2)O(2) synergistically enhanced LPS-induced TNF-alpha production in RAW264.7 cells, accompanied by an up-regulation of CD14 mRNA. Moreover, co-treatment with TNF-alpha- and H(2)O(2)-induced apoptosis in primary hepatocytes, although neither TNF-alpha nor H(2)O(2) could do so independently. CONCLUSIONS LPS up-regulated TNF-alpha production, which induced hepatocyte apoptosis in a murine NASH model. LPS may play a key role in the pathogenesis of NASH.
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Affiliation(s)
- Hiroshi Kudo
- Third Department of Internal Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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23
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Schwimmer JB, Celedon MA, Lavine JE, Salem R, Campbell N, Schork NJ, Shiehmorteza M, Yokoo T, Chavez A, Middleton MS, Sirlin CB. Heritability of nonalcoholic fatty liver disease. Gastroenterology 2009; 136:1585-92. [PMID: 19208353 PMCID: PMC3397140 DOI: 10.1053/j.gastro.2009.01.050] [Citation(s) in RCA: 319] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Revised: 12/30/2008] [Accepted: 01/22/2009] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the United States. The etiology is believed to be multifactorial with a substantial genetic component; however, the heritability of NAFLD is undetermined. Therefore, a familial aggregation study was performed to test the hypothesis that NAFLD is highly heritable. METHODS Overweight children with biopsy-proven NAFLD and overweight children without NAFLD served as probands. Family members were studied, including the use of magnetic resonance imaging to quantify liver fat fraction. Fatty liver was defined as a liver fat fraction of 5% or higher. Etiologies for fatty liver other than NAFLD were excluded. Narrow-sense heritability estimates for fatty liver (dichotomous) and fat fraction (continuous) were calculated using variance components analysis adjusted for covariate effects. RESULTS Fatty liver was present in 17% of siblings and 37% of parents of overweight children without NAFLD. Fatty liver was significantly more common in siblings (59%) and parents (78%) of children with NAFLD. Liver fat fraction was correlated with body mass index, although the correlation was significantly stronger for families of children with NAFLD than those without NAFLD. Adjusted for age, sex, race, and body mass index, the heritability of fatty liver was 1.000 and of liver fat fraction was 0.386. CONCLUSIONS Family members of children with NAFLD should be considered at high risk for NAFLD. These data suggest that familial factors are a major determinant of whether an individual has NAFLD. Studies examining the complex relations between genes and environment in the development and progression of NAFLD are warranted.
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Affiliation(s)
- Jeffrey B Schwimmer
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of California, San Diego School of Medicine, San Diego, California 92103, USA.
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24
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Brun P, Castagliuolo I, Di Leo V, Buda A, Pinzani M, Palù G, Martines D. Increased intestinal permeability in obese mice: new evidence in the pathogenesis of nonalcoholic steatohepatitis. Am J Physiol Gastrointest Liver Physiol 2007; 292:G518-25. [PMID: 17023554 DOI: 10.1152/ajpgi.00024.2006] [Citation(s) in RCA: 600] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A small percentage of pathologically obese subjects with fatty livers develop histological signs of necroinflammation and fibrosis, suggesting a variety of cofactors in the pathogenesis of obesity-related liver diseases including nonalcoholic steatohepatitis. Since several observations have linked bacterial endotoxins to liver damage, the aim of this study was to determine the effect of obesity on intestinal mucosal integrity and portal blood endotoxemia in two strains of obese mice: leptin-deficient (ob/ob) and hyperleptinemic (db/db) mice. Murine intestinal mucosal barrier function was assessed using a Ussing chamber, whereas ileum tight junction proteins were analyzed by immunocytochemistry and Western blot analysis. Circulating proinflammatory cytokines and portal blood endotoxin levels were measured by ELISA and the limulus test, respectively. The inflammatory and fibrogenic phenotype of murine hepatic stellate cells (HSCs) was determined by ELISA and quantitative RT-PCR. Ob/ob and db/db mice showed lower intestinal resistance, profoundly modified distribution of occludin and zonula occludens-1 in the intestinal mucosa, and higher circulating levels of inflammatory cytokines and portal endotoxemia compared with lean control mice. Moreover, HSCs isolated from ob/ob and db/db mice showed higher membrane CD14 mRNA levels and more pronounced lipopolysaccharide-induced proinflammatory and fibrogenic responses than HSCs from lean animals. In conclusion, genetically obese mice display enhanced intestinal permeability leading to increased portal endotoxemia that makes HSCs more sensitive to bacterial endotoxins. We suggest that in metabolic syndrome, patients may likewise have a greater intestinal mucosa permeability and increased lipopolysaccharide levels in portal blood that can contribute to the liver inflammatory damage.
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Affiliation(s)
- Paola Brun
- Department of Histology, Univ of Padua, Via Gabelli 63, Padova, Italy
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