1
|
Klag KA, Bell R, Jia X, Seguin A, Maschek JA, Bronner M, Cox JE, Round JL, Ward DM. Low-Iron Diet-Induced Fatty Liver Development Is Microbiota Dependent and Exacerbated by Loss of the Mitochondrial Iron Importer Mitoferrin2. Nutrients 2024; 16:1804. [PMID: 38931165 PMCID: PMC11206261 DOI: 10.3390/nu16121804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/28/2024] Open
Abstract
Iron deficiency is the number one nutritional problem worldwide. Iron uptake is regulated at the intestine and is highly influenced by the gut microbiome. Blood from the intestines drains directly into the liver, informing iron status and gut microbiota status. Changes in either iron or the microbiome are tightly correlated with the development of metabolic dysfunction-associated steatotic liver disease (MASLD). To investigate the underlying mechanisms of the development of MASLD that connect altered iron metabolism and gut microbiota, we compared specific pathogen free (SPF) or germ-free (GF) mice, fed a normal or low-iron diet. SPF mice on a low-iron diet showed reduced serum triglycerides and MASLD. In contrast, GF low-iron diet-fed mice showed increased serum triglycerides and did not develop hepatic steatosis. SPF mice showed significant changes in liver lipid metabolism and increased insulin resistance that was dependent upon the presence of the gut microbiota. We report that total body loss of mitochondrial iron importer Mitoferrin2 (Mfrn2-/-) exacerbated the development of MASLD on a low-iron diet with significant lipid metabolism alterations. Our study demonstrates a clear contribution of the gut microbiome, dietary iron, and Mfrn2 in the development of MASLD and metabolic syndrome.
Collapse
Affiliation(s)
- Kendra A. Klag
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (K.A.K.); (R.B.); (X.J.); (A.S.); (M.B.); (J.L.R.)
| | - Rickesha Bell
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (K.A.K.); (R.B.); (X.J.); (A.S.); (M.B.); (J.L.R.)
| | - Xuan Jia
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (K.A.K.); (R.B.); (X.J.); (A.S.); (M.B.); (J.L.R.)
| | - Alexandra Seguin
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (K.A.K.); (R.B.); (X.J.); (A.S.); (M.B.); (J.L.R.)
| | - J. Alan Maschek
- Metabolomics Core Research Facility, University of Utah, Salt Lake City, UT 84112, USA; (J.A.M.); (J.E.C.)
| | - Mary Bronner
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (K.A.K.); (R.B.); (X.J.); (A.S.); (M.B.); (J.L.R.)
- Huntsman Cancer Institute, Salt Lake City, UT 84112, USA
| | - James E. Cox
- Metabolomics Core Research Facility, University of Utah, Salt Lake City, UT 84112, USA; (J.A.M.); (J.E.C.)
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - June L. Round
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (K.A.K.); (R.B.); (X.J.); (A.S.); (M.B.); (J.L.R.)
| | - Diane M. Ward
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (K.A.K.); (R.B.); (X.J.); (A.S.); (M.B.); (J.L.R.)
| |
Collapse
|
2
|
Dietary Iron Overload Differentially Modulates Chemically-Induced Liver Injury in Rats. Nutrients 2020; 12:nu12092784. [PMID: 32932999 PMCID: PMC7551424 DOI: 10.3390/nu12092784] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 02/07/2023] Open
Abstract
Hepatic iron overload is well known as an important risk factor for progression of liver diseases; however, it is unknown whether it can alter the susceptibility to drug-induced hepatotoxicity. Here we investigate the pathological roles of iron overload in two single-dose models of chemically-induced liver injury. Rats were fed a high-iron (Fe) or standard diet (Cont) for four weeks and were then administered with allyl alcohol (AA) or carbon tetrachloride (CCl4). Twenty-four hours after administration mild mononuclear cell infiltration was seen in the periportal/portal area (Zone 1) in Cont-AA group, whereas extensive hepatocellular necrosis was seen in Fe-AA group. Centrilobular (Zone 3) hepatocellular necrosis was prominent in Cont-CCl4 group, which was attenuated in Fe-CCl4 group. Hepatic lipid peroxidation and hepatocellular DNA damage increased in Fe-AA group compared with Cont-AA group. Hepatic caspase-3 cleavage increased in Cont-CCl4 group, which was suppressed in Fe-CCl4 group. Our results showed that dietary iron overload exacerbates AA-induced Zone-1 liver injury via enhanced oxidative stress while it attenuates CCl4-induced Zone-3 liver injury, partly via the suppression of apoptosis pathway. This study suggested that susceptibility to drugs or chemical compounds can be differentially altered in iron-overloaded livers.
Collapse
|
3
|
Sousa L, Oliveira MM, Pessôa MTC, Barbosa LA. Iron overload: Effects on cellular biochemistry. Clin Chim Acta 2019; 504:180-189. [PMID: 31790701 DOI: 10.1016/j.cca.2019.11.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 02/07/2023]
Abstract
Iron is an essential element for human life. However, it is a pro-oxidant agent capable of reacting with hydrogen peroxide. An iron overload can cause cellular changes, such as damage to the plasma membrane leading to cell death. Effects of iron overload in cellular biochemical processes include modulating membrane enzymes, such as the Na, K-ATPase, impairing the ionic transport and inducing irreversible damage to cellular homeostasis. To avoid such damage, cells have an antioxidant system that acts in an integrated manner to prevent oxidative stress. In addition, the cells contain proteins responsible for iron transport and storage, preventing its reaction with other substances during absorption. Moreover, iron is associated with cellular events coordinated by iron-responsive proteins (IRPs) that regulate several cellular functions, including a process of cell death called ferroptosis. This review will address the biochemical aspects of iron overload at the cellular level and its effects on important cellular structures.
Collapse
Affiliation(s)
- Leilismara Sousa
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, MG, Brazil
| | - Marina M Oliveira
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, MG, Brazil
| | - Marco Túlio C Pessôa
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, MG, Brazil
| | - Leandro A Barbosa
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, MG, Brazil.
| |
Collapse
|
4
|
Yang Z, Wu J, Li X, Xie D, Wang Y, Yang T. Association between dietary iron intake and the prevalence of nonalcoholic fatty liver disease: A cross-sectional study. Medicine (Baltimore) 2019; 98:e17613. [PMID: 31651873 PMCID: PMC6824640 DOI: 10.1097/md.0000000000017613] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The aim was to test the association between dietary iron intake and the prevalence of nonalcoholic fatty liver disease (NAFLD) in a large sample of middle-aged and elderly Chinese population.The data included in this analysis were collected from a population-based cross-sectional study, that is, the Xiangya Hospital Health Management Center Study. Dietary iron intake was assessed using a validated semiquantitative food frequency questionnaire. The relationship between dietary iron intake and the prevalence of NAFLD was examined using logistic and spline regressions.A cross-sectional study including 5445 subjects was conducted. The prevalence of NAFLD was 36.9%. Compared with the lowest quintile, the energy-adjusted odds ratios (ORs) of NAFLD were 1.33 (95% confidence interval [CI]: 1.07-1.64), 1.80 (95% CI: 1.41-2.29) and 2.11 (95% CI: 1.60-2.80) in the 3rd, 4th, and 5th quintile of iron intake, respectively (P-value for trend <.001). In addition, dietary iron intake was positively associated with the OR of NAFLD in a dose-response relationship manner (test for trend P < .001). However, after stratifying the data by gender, such association only remained in the male, but not in the female population. With adjustment of additional potential confounders, the results did not change materially.Subjects with higher dietary iron intake were subject to a higher prevalence of NAFLD in a dose-response relationship manner. However, such association probably only exists in males, but not in females.
Collapse
Affiliation(s)
- Zidan Yang
- Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University
| | - Jing Wu
- Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University
| | - Xiaoxiao Li
- Hunan Key Laboratory of Joint Degeneration and Injury
| | - Dongxing Xie
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yilun Wang
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Tubao Yang
- Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University
| |
Collapse
|
5
|
Xiao L, Luo G, Tang Y, Yao P. Quercetin and iron metabolism: What we know and what we need to know. Food Chem Toxicol 2018; 114:190-203. [PMID: 29432835 DOI: 10.1016/j.fct.2018.02.022] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 01/18/2018] [Accepted: 02/07/2018] [Indexed: 12/14/2022]
Abstract
Iron is a life-supporting micronutrient that is required in the human diet, and is essential for maintaining physiological homeostasis. Properly harnessing a redox-active metal such as iron is a great challenge for cells and organisms because an excess of highly reactive iron catalyzes the formation of reactive oxygen species and can lead to cell and tissue damage. Quercetin is a typical flavonoid that is commonly found in fruits and vegetables and has versatile biological effects. From a classical viewpoint, owing to its unique chemical characteristics, quercetin has long been associated with iron metabolism only in the context of its iron-chelating and ROS-scavenging activities. However, within the field of human iron biology, expanding concepts of the roles of quercetin are flourishing, and great strides are being made in understanding the interactions between quercetin and iron. This progress highlights the varied roles of quercetin in iron metabolism, which involve much more than iron chelation alone. A review of these studies provides an ideal context to summarize recent progress and discuss compelling evidence for therapeutic opportunities that could arise from a better understanding of the underlying mechanisms.
Collapse
Affiliation(s)
- Lin Xiao
- Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Hubei Key Laboratory of Food Nutrition and Safety, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Ministry of Education Key Laboratory of Environment, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Gang Luo
- Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Hubei Key Laboratory of Food Nutrition and Safety, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Ministry of Education Key Laboratory of Environment, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yuhan Tang
- Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Hubei Key Laboratory of Food Nutrition and Safety, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Ministry of Education Key Laboratory of Environment, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Ping Yao
- Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Hubei Key Laboratory of Food Nutrition and Safety, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Ministry of Education Key Laboratory of Environment, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| |
Collapse
|
6
|
Shi W, Wang H, Zheng X, Jiang X, Xu Z, Shen H, Li M. HNF-4alpha Negatively Regulates Hepcidin Expression Through BMPR1A in HepG2 Cells. Biol Trace Elem Res 2017; 176:294-304. [PMID: 27660075 DOI: 10.1007/s12011-016-0846-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/06/2016] [Indexed: 12/19/2022]
Abstract
Hepcidin synthesis is reported to be inadequate according to the body iron store in patients with non-alcoholic fatty liver disease (NAFLD) undergoing hepatic iron overload (HIO). However, the underlying mechanisms remain unclear. We hypothesize that hepatocyte nuclear factor-4α (HNF-4α) may negatively regulate hepcidin expression and contribute to hepcidin deficiency in NAFLD patients. The effect of HNF-4α on hepcidin expression was observed by transfecting specific HNF-4α small interfering RNA (siRNA) or plasmids into HepG2 cells. Both direct and indirect mechanisms involved in the regulation of HNF-4α on hepcidin were detected by real-time PCR, Western blotting, chromatin immunoprecipitation (chIP), and reporter genes. It was found that HNF-4α suppressed hepcidin messenger RNA (mRNA) and protein expressions in HepG2 cells, and this suppressive effect was independent of the potential HNF-4α response elements. Phosphorylation of SMAD1 but not STAT3 was inactivated by HNF-4α, and the SMAD4 response element was found essential to HNF-4α-induced hepcidin reduction. Neither inhibitory SMADs, SMAD6, and SMAD7 nor BMPR ligands, BMP2, BMP4, BMP6, and BMP7 were regulated by HNF-4α in HepG2 cells. BMPR1A, but not BMPR1B, BMPR2, ActR2A, ActR2B, or HJV, was decreased by HNF-4α, and HNF4α-knockdown-induced stimulation of hepcidin could be entirely blocked when BMPR1A was interfered with at the same time. In conclusion, the present study suggests that HNF-4α has a suppressive effect on hepcidin expression by inactivating the BMP pathway, specifically via BMPR1A, in HepG2 cells.
Collapse
Affiliation(s)
- Wencai Shi
- Military Hygiene Department, Faculty of Naval Medicine, Second Military Medical University, No. 800 Xiangyin Road, Shanghai, 200433, China
- Department of Clinical Nutrition, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Heyang Wang
- Military Hygiene Department, Faculty of Naval Medicine, Second Military Medical University, No. 800 Xiangyin Road, Shanghai, 200433, China
| | - Xuan Zheng
- Department of Clinical Nutrition, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Xin Jiang
- Military Hygiene Department, Faculty of Naval Medicine, Second Military Medical University, No. 800 Xiangyin Road, Shanghai, 200433, China
| | - Zheng Xu
- Military Hygiene Department, Faculty of Naval Medicine, Second Military Medical University, No. 800 Xiangyin Road, Shanghai, 200433, China
| | - Hui Shen
- Military Hygiene Department, Faculty of Naval Medicine, Second Military Medical University, No. 800 Xiangyin Road, Shanghai, 200433, China
| | - Min Li
- Military Hygiene Department, Faculty of Naval Medicine, Second Military Medical University, No. 800 Xiangyin Road, Shanghai, 200433, China.
| |
Collapse
|
7
|
Sikorska K, Bernat A, Wroblewska A. Molecular pathogenesis and clinical consequences of iron overload in liver cirrhosis. Hepatobiliary Pancreat Dis Int 2016; 15:461-479. [PMID: 27733315 DOI: 10.1016/s1499-3872(16)60135-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND The liver, as the main iron storage compartment and the place of hepcidin synthesis, is the central organ involved in maintaining iron homeostasis in the body. Excessive accumulation of iron is an important risk factor in liver disease progression to cirrhosis and hepatocellular carcinoma. Here, we review the literature on the molecular pathogenesis of iron overload and its clinical consequences in chronic liver diseases. DATA SOURCES PubMed was searched for English-language articles on molecular genesis of primary and secondary iron overload, as well as on their association with liver disease progression. We have also included literature on adjuvant therapeutic interventions aiming to alleviate detrimental effects of excessive body iron load in liver cirrhosis. RESULTS Excess of free, unbound iron induces oxidative stress, increases cell sensitivity to other detrimental factors, and can directly affect cellular signaling pathways, resulting in accelerated liver disease progression. Diagnosis of liver cirrhosis is, in turn, often associated with the identification of a pathological accumulation of iron, even in the absence of genetic background of hereditary hemochromatosis. Iron depletion and adjuvant therapy with antioxidants are shown to cause significant improvement of liver functions in patients with iron overload. Phlebotomy can have beneficial effects on liver histology in patients with excessive iron accumulation combined with compensated liver cirrhosis of different etiology. CONCLUSION Excessive accumulation of body iron in liver cirrhosis is an important predictor of liver failure and available data suggest that it can be considered as target for adjuvant therapy in this condition.
Collapse
Affiliation(s)
- Katarzyna Sikorska
- Department of Tropical Medicine and Epidemiology, Medical University of Gdansk, Powstania Styczniowego 9b, 81-519 Gdynia, Poland.
| | | | | |
Collapse
|
8
|
Ye Q, Qian BX, Yin WL, Wang FM, Han T. Association between the HFE C282Y, H63D Polymorphisms and the Risks of Non-Alcoholic Fatty Liver Disease, Liver Cirrhosis and Hepatocellular Carcinoma: An Updated Systematic Review and Meta-Analysis of 5,758 Cases and 14,741 Controls. PLoS One 2016; 11:e0163423. [PMID: 27657935 PMCID: PMC5033482 DOI: 10.1371/journal.pone.0163423] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 09/08/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Conflicting results have been obtained for the association between two common polymorphisms (C282Y, H63D) of human HFE (hereditary hemochromatosis) gene and the risks of the liver diseases, including non-alcoholic fatty liver disease (NAFLD), liver cirrhosis and hepatocellular carcinoma (HCC). METHODS An updated systematic review and meta-analysis was conducted to evaluate the potential role of HFE polymorphisms in the susceptibility to NAFLD, liver cirrhosis and HCC. After retrieving articles from online databases, eligible studies were enrolled according to the selection criteria. Stata/SE 12.0 software was utilized to perform the statistical analysis. RESULTS In total, 43 articles with 5,758 cases and 14,741 controls were selected. Compared with the control group, a significantly increased risk of NAFLD was observed for the C282Y polymorphism in the Caucasian population under all genetic models and for the H63D polymorphism under the allele, heterozygote and dominant models (all OR>1, Passociation<0.05). However, no significant difference between liver cirrhosis cases and the control group was observed for HFE C282Y and H63D (all Passociation>0.05). In addition, we found that HFE C282Y was statistically associated with increased HCC susceptibility in the overall population, while H63D increased the odds of developing non-cirrhotic HCC in the African population (all OR>1, Passociation<0.05). Moreover, a positive association between compound heterozygosity for C282Y/H63D and the risk of NAFLD and HCC, but not liver cirrhosis, was observed. CONCLUSION Our meta-analysis provides evidence that the HFE C282Y and H63D polymorphisms confer increased genetic susceptibility to NAFLD and HCC but not liver cirrhosis. Additional well-powered studies are required to confirm our conclusion.
Collapse
Affiliation(s)
- Qing Ye
- The Third Central clinical college of Tianjin Medical University, Tianjin, PR China
- Department of Gastroenterology and Hepatology, Tianjin Third Central Hospital, Tianjin, PR China
- Tianjin Institute of Hepatobiliary Disease, Tianjin, PR China
- Tianjin Key Laboratory of Artificial Cells, Tianjin, PR China
| | - Bao-Xin Qian
- The Third Central clinical college of Tianjin Medical University, Tianjin, PR China
- Department of Gastroenterology and Hepatology, Tianjin Third Central Hospital, Tianjin, PR China
- Tianjin Institute of Hepatobiliary Disease, Tianjin, PR China
- Tianjin Key Laboratory of Artificial Cells, Tianjin, PR China
| | - Wei-Li Yin
- The Third Central clinical college of Tianjin Medical University, Tianjin, PR China
- Department of Gastroenterology and Hepatology, Tianjin Third Central Hospital, Tianjin, PR China
- Tianjin Institute of Hepatobiliary Disease, Tianjin, PR China
- Tianjin Key Laboratory of Artificial Cells, Tianjin, PR China
| | - Feng-Mei Wang
- The Third Central clinical college of Tianjin Medical University, Tianjin, PR China
- Department of Gastroenterology and Hepatology, Tianjin Third Central Hospital, Tianjin, PR China
- Tianjin Institute of Hepatobiliary Disease, Tianjin, PR China
- Tianjin Key Laboratory of Artificial Cells, Tianjin, PR China
| | - Tao Han
- The Third Central clinical college of Tianjin Medical University, Tianjin, PR China
- Department of Gastroenterology and Hepatology, Tianjin Third Central Hospital, Tianjin, PR China
- Tianjin Institute of Hepatobiliary Disease, Tianjin, PR China
- Tianjin Key Laboratory of Artificial Cells, Tianjin, PR China
- * E-mail:
| |
Collapse
|
9
|
Milic S, Mikolasevic I, Orlic L, Devcic E, Starcevic-Cizmarevic N, Stimac D, Kapovic M, Ristic S. The Role of Iron and Iron Overload in Chronic Liver Disease. Med Sci Monit 2016; 22:2144-51. [PMID: 27332079 PMCID: PMC4922827 DOI: 10.12659/msm.896494] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The liver plays a major role in iron homeostasis; thus, in patients with chronic liver disease, iron regulation may be disturbed. Higher iron levels are present not only in patients with hereditary hemochromatosis, but also in those with alcoholic liver disease, nonalcoholic fatty liver disease, and hepatitis C viral infection. Chronic liver disease decreases the synthetic functions of the liver, including the production of hepcidin, a key protein in iron metabolism. Lower levels of hepcidin result in iron overload, which leads to iron deposits in the liver and higher levels of non-transferrin-bound iron in the bloodstream. Iron combined with reactive oxygen species leads to an increase in hydroxyl radicals, which are responsible for phospholipid peroxidation, oxidation of amino acid side chains, DNA strain breaks, and protein fragmentation. Iron-induced cellular damage may be prevented by regulating the production of hepcidin or by administering hepcidin agonists. Both of these methods have yielded successful results in mouse models.
Collapse
Affiliation(s)
- Sandra Milic
- Department of Gastroenterology, UHC Rijeka, Rijeka, Croatia
| | | | - Lidija Orlic
- Department of Nephrology, Dialysis and Kidney Transplantation, UHC Rijeka, Rijeka, Croatia
| | - Edita Devcic
- Department of Gastroenterology, UHC Rijeka, Rijeka, Croatia
| | | | - Davor Stimac
- Department of Gastroenterology, UHC Rijeka, Rijeka, Croatia
| | - Miljenko Kapovic
- Department of Biology and Medical Genetics, Faculty of Medicine, Rijeka, Croatia
| | - Smiljana Ristic
- Department of Biology and Medical Genetics, Faculty of Medicine, Rijeka, Croatia
| |
Collapse
|
10
|
Abstract
Liver fat, iron, and combined overload are common manifestations of diffuse liver disease and may cause lipotoxicity and iron toxicity via oxidative hepatocellular injury, leading to progressive fibrosis, cirrhosis, and eventually, liver failure. Intracellular fat and iron cause characteristic changes in the tissue magnetic properties in predictable dose-dependent manners. Using dedicated magnetic resonance pulse sequences and postprocessing algorithms, fat and iron can be objectively quantified on a continuous scale. In this article, we will describe the basic physical principles of magnetic resonance fat and iron quantification and review the imaging techniques of the "past, present, and future." Standardized radiological metrics of fat and iron are introduced for numerical reporting of overload severity, which can be used toward objective diagnosis, grading, and longitudinal disease monitoring. These noninvasive imaging techniques serve an alternative or complimentary role to invasive liver biopsy. Commercial solutions are increasingly available, and liver fat and iron quantitative imaging is now within reach for routine clinical use and may soon become standard of care.
Collapse
Affiliation(s)
- Takeshi Yokoo
- From the *Department of Radiology, †Advanced Imaging Research Center, and ‡Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | | |
Collapse
|