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Klement L, Jansakun C, Yan B, Staffer S, Tuma-Kellner S, Altamura S, Muckenthaler M, Merle U, Chamulitrat W. Myeloid-specific deletion of group VIA calcium-independent phospholipase A2 induces pro-inflammatory LPS response predominantly in male mice via MIP-1α activation. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167016. [PMID: 38198970 DOI: 10.1016/j.bbadis.2024.167016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 12/15/2023] [Accepted: 12/31/2023] [Indexed: 01/12/2024]
Abstract
Polymorphisms of group VIA calcium-independent phospholipase A2 (PLA2G6) are associated with blood C-reactive protein suggesting its role in inflammation. We showed that myeloid-specific Pla2g6-deficiency in Pla2g6M-/- mice led to exaggerated inflammation and fibrosis in a lean fatty liver model. We here investigated whether these mutants display alteration in immune response after treatment with E. coli lipopolysaccharides (LPS) under acute (a single dose) and persistent (four doses) conditions. Without LPS treatment, male Pla2g6M-/- (but not Flox) mice at 12 months of age exhibited splenomegaly and hepatic necrosis, and ~ 30 % of them exhibited autoimmune hepatitis showing lymphoplasma cells with CD3(+) and CD45R(+) staining. Under acute LPS, male mutants showed an elevation of plasma MIP-1α and immunoglobulinA as well as upregulation of hepatic apoptosis and fibrosis PARP-1, Bax, MCP-1, α-SMA, and collagen I proteins. Their bone-marrow-derived macrophages also showed an elevation of MIP-1α release upon LPS stimulation in vitro. Female mutants under acute LPS showed a moderate increase in plasma KC/CXCL1, MCP-1, and IL10, and they showed no remarkable increase in hepatic fibrosis under acute or persistent LPS. Male mutants under persistent LPS displayed an elevation of aspartate aminotransferase, blood eosinophils, and hepatic apoptosis. Moreover, ~30 % of these mutants exhibited eosinophilic sclerosing portal hepatitis associated with an upregulated protein expression of hepatic CD8α, CD68, eosinophilic cationic protein, and Ly6G. Thus, myeloid-PLA2G6 deficiency led to an autoimmune and LPS-induced inflammatory liver disease via MIP-1α in a male-predominant manner. Our results may be applicable to patients with PLA2G6 mutations who undergo bacterial infection and sepsis.
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Affiliation(s)
- Lukas Klement
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Chutima Jansakun
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80161, Thailand
| | - Bin Yan
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Simone Staffer
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sandro Altamura
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany
| | - Martina Muckenthaler
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany; Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), German Centre for Cardiovascular Research, Partner Site, University of Heidelberg, Germany
| | - Uta Merle
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Walee Chamulitrat
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
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Li H, Seessle J, Staffer S, Tuma-Kellner S, Poschet G, Herrmann T, Chamulitrat W. FATP4 deletion in liver cells induces elevation of extracellular lipids via metabolic channeling towards triglycerides and lipolysis. Biochem Biophys Res Commun 2023; 687:149161. [PMID: 37931418 DOI: 10.1016/j.bbrc.2023.149161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/13/2023] [Accepted: 10/26/2023] [Indexed: 11/08/2023]
Abstract
Evidence from mice with global deletion of fatty-acid transport protein4 (FATP4) indicates its role on β-oxidation and triglycerides (TG) metabolism. We reported that plasma glycerol and free fatty acids (FA) were increased in liver-specific Fatp4 deficient (L-FATP4-/-) mice under dietary stress. We hypothesized that FATP4 may mediate hepatocellular TG lipolysis. Here, we demonstrated that L-FATP4-/- mice showed an increase in these blood lipids, liver TG, and subcutaneous fat weights. We therefore studied TG metabolism in response to oleate treatment in two experimental models using FATP4-knockout HepG2 (HepKO) cells and L-FATP4-/- hepatocytes. Both FATP4-deificient liver cells showed a significant decrease in β-oxidation products by ∼30-35% concomitant with marked upregulation of CD36, FATP2, and FATP5 as well as lipoprotein microsomal-triglyceride-transfer protein genes. By using 13C3D5-glycerol, HepKO cells displayed an increase in metabolically labelled TG species which were further increased with oleate treatment. This increase was concomitant with a step-wise elevation of TG in cells and supernatants as well as the secretion of cholesterol very low-density and high-density lipoproteins. Upon analyzing TG lipolytic enzymes, both mutant liver cells showed marked upregulated expression of hepatic lipase, while that of hormone-sensitive lipase and adipose-triglyceride lipase was downregulated. Lipolysis measured by extracellular glycerol and free FA was indeed increased in mutant cells, and this event was exacerbated by oleate treatment. Taken together, FATP4 deficiency in liver cells led to a metabolic shift from β-oxidation towards lipolysis-directed TG and lipoprotein secretion, which is in line with an association of FATP4 polymorphisms with blood lipids.
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Affiliation(s)
- Huili Li
- Department of Internal Medicine IV, University Hospital Heidelberg, 69120, Heidelberg, Germany; Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022, Wuhan, Hubei, China
| | - Jessica Seessle
- Department of Internal Medicine IV, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Simone Staffer
- Department of Internal Medicine IV, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Gernot Poschet
- Metabolomics Core Technology Platform, Centre for Organismal Studies, University of Heidelberg, 69120, Heidelberg, Germany
| | - Thomas Herrmann
- Westkuesten Hospital, Esmarchstraße 50, 25746, Heide, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University Hospital Heidelberg, 69120, Heidelberg, Germany.
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Göcebe D, Jansakun C, Zhang Y, Staffer S, Tuma-Kellner S, Altamura S, Muckenthaler MU, Merle U, Herrmann T, Chamulitrat W. Myeloid-specific fatty acid transport protein 4 deficiency induces a sex-dimorphic susceptibility for nonalcoholic steatohepatitis in mice fed a high-fat, high-cholesterol diet. Am J Physiol Gastrointest Liver Physiol 2023; 324:G389-G403. [PMID: 36881564 PMCID: PMC10085558 DOI: 10.1152/ajpgi.00181.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 02/17/2023] [Accepted: 02/26/2023] [Indexed: 03/08/2023]
Abstract
Newborns with FATP4 mutations exhibit ichthyosis prematurity syndrome (IPS), and adult patients show skin hyperkeratosis, allergies, and eosinophilia. We have previously shown that the polarization of macrophages is altered by FATP4 deficiency; however, the role of myeloid FATP4 in the pathogenesis of nonalcoholic steatohepatitis (NASH) is not known. We herein phenotyped myeloid-specific Fatp4-deficient (Fatp4M-/-) mice under chow and high-fat, high-cholesterol (HFHC) diet. Bone-marrow-derived macrophages (BMDMs) from Fatp4M-/- mice showed significant reduction in cellular sphingolipids in males and females, and additionally phospholipids in females. BMDMs and Kupffer cells from Fatp4M-/- mice exhibited increased LPS-dependent activation of proinflammatory cytokines and transcription factors PPARγ, CEBPα, and p-FoxO1. Correspondingly, these mutants under chow diet displayed thrombocytopenia, splenomegaly, and elevated liver enzymes. After HFHC feeding, Fatp4M-/- mice showed increased MCP-1 expression in livers and subcutaneous fat. Plasma MCP-1, IL4, and IL13 levels were elevated in male and female mutants, and female mutants additionally showed elevation of IL5 and IL6. After HFHC feeding, male mutants showed an increase in hepatic steatosis and inflammation, whereas female mutants showed a greater severity in hepatic fibrosis associated with immune cell infiltration. Thus, myeloid-FATP4 deficiency led to steatotic and inflammatory NASH in males and females, respectively. Our work offers some implications for patients with FATP4 mutations and also highlights considerations in the design of sex-targeted therapies for NASH treatment.NEW & NOTEWORTHY FATP4 deficiency in BMDMs and Kupffer cells led to increased proinflammatory response. Fatp4M-/- mice displayed thrombocytopenia, splenomegaly, and elevated liver enzymes. In response to HFHC feeding, male mutants were prone to hepatic steatosis, whereas female mutants showed exaggerated fibrosis. Our study provides insights into a sex-dimorphic susceptibility to NASH by myeloid-FATP4 deficiency.
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Affiliation(s)
- Deniz Göcebe
- Department of Internal Medicine IV, University Hospital Heidelberg, Heidelberg, Germany
| | - Chutima Jansakun
- Department of Internal Medicine IV, University Hospital Heidelberg, Heidelberg, Germany
- School of Allied Health Sciences, Walailak University, Nakhonsrithammarat, Thailand
| | - Yuling Zhang
- Department of Internal Medicine IV, University Hospital Heidelberg, Heidelberg, Germany
| | - Simone Staffer
- Department of Internal Medicine IV, University Hospital Heidelberg, Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University Hospital Heidelberg, Heidelberg, Germany
| | - Sandro Altamura
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Heidelberg, Germany
| | - Martina U Muckenthaler
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Heidelberg, Germany
- Translational Lung Research Center Heidelberg, German Center for Lung Research (DZL), German Centre for Cardiovascular Research, Partner Site, University of Heidelberg, Heidelberg, Germany
| | - Uta Merle
- Department of Internal Medicine IV, University Hospital Heidelberg, Heidelberg, Germany
| | | | - Walee Chamulitrat
- Department of Internal Medicine IV, University Hospital Heidelberg, Heidelberg, Germany
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Jansakun C, Chunglok W, Altamura S, Muckenthaler M, Staffer S, Tuma-Kellner S, Merle U, Chamulitrat W. Myeloid- and hepatocyte-specific deletion of group VIA calcium-independent phospholipase A2 leads to dichotomous opposing phenotypes during MCD diet-induced NASH. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166590. [PMID: 36334837 DOI: 10.1016/j.bbadis.2022.166590] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/25/2022] [Accepted: 10/25/2022] [Indexed: 11/05/2022]
Abstract
Polymorphisms of phospholipase A2VIA (iPLA2β or PLA2G6) are associated with body weights and blood C-reactive protein. The role of iPLA2β/PLA2G6 in non-alcoholic steatohepatitis (NASH) is still elusive because female iPla2β-null mice showed attenuated hepatic steatosis but exacerbated hepatic fibrosis after feeding with methionine- and choline-deficient diet (MCDD). Herein, female mice with myeloid- (MPla2g6-/-) and hepatocyte- (LPla2g6-/-) specific PLA2G6 deletion were generated and phenotyped after MCDD feeding. Without any effects on hepatic steatosis, MCDD-fed MPla2g6-/- mice showed further exaggeration of liver inflammation and fibrosis as well as elevation of plasma TNFα, CCL2, and circulating monocytes. Bone-marrow-derived macrophages (BMDMs) from MPla2g6-/- mice displayed upregulation of PPARγ and CEBPα proteins, and elevated release of IL6 and CXCL1 under LPS stimulation. LPS-stimulated BMDMs from MCDD-fed MPla2g6-/- mice showed suppressed expression of M1 Tnfa and Il6, but marked upregulation of M2 Arg1, Chil3, IL10, and IL13 as well as chemokine receptors Ccr2 and Ccr5. This in vitro shift was associated with exaggeration of hepatic M1/M2 cytokines, chemokines/chemokine receptors, and fibrosis genes. Contrarily, MCDD-fed LPla2g6-/- mice showed a complete protection which was associated with upregulation of Ppara/PPARα and attenuated expression of Pparg/PPARγ, fatty-acid uptake, triglyceride synthesis, and de novo lipogenesis genes. Interestingly, LPla2g6-/- mice fed with chow or MCDD displayed an attenuation of blood monocytes and elevation of anti-inflammatory lipoxin A4 in plasma and liver. Thus, PLA2G6 inactivation specifically in myeloid cells and hepatocytes led to opposing phenotypes in female mice undergoing NASH. Hepatocyte-specific PLA2G6 inhibitors may be further developed for treatment of this disease.
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Affiliation(s)
- Chutima Jansakun
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80161, Thailand
| | - Warangkana Chunglok
- School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80161, Thailand
| | - Sandro Altamura
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany
| | - Martina Muckenthaler
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany; Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), German Centre for Cardiovascular Research, Partner Site, University of Heidelberg, Germany
| | - Simone Staffer
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Uta Merle
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Walee Chamulitrat
- Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
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Wong HY, Langlotz M, Gan-Schreier H, Xu W, Staffer S, Tuma-Kellner S, Liebisch G, Merle U, Chamulitrat W. Constitutive oxidants from hepatocytes of male iPLA2β-null mice increases the externalization of phosphatidylethanolamine on plasma membrane. Free Radic Res 2021; 55:625-633. [PMID: 34696671 DOI: 10.1080/10715762.2021.1987426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We have found that group VIA calcium-independent phospholipase A2 (iPLA2β) has specificity for hydrolysis of phosphatidylethanolamine (PE) in mouse livers. Phospholipids (PLs) are transported to plasma membrane and some PLs including PE are externalized to maintain membrane PL asymmetry. Here we demonstrated that hepatocytes of iPLA2β-null (KO) mice showed an increase in PE containing palmitate and oleate. We aimed to examine whether externalization of PE on the outer leaflets could be affected by iPLA2β deficiency and its modulation by reactive oxygen species (ROS) or apoptosis. As duramycin has high affinity to PE, we used duramycin conjugated with biotin (DLB) and streptavidin 488 as a probe for detection of externalized PE. Compared to WT, naïve KO hepatocytes showed an increase in both PE externalization and ROS generation. These events were observed in male but not in female KO mice. Hydrogen peroxide or menadione treatment enhanced PE externalization to the same extent for both male/female WT and KO hepatocytes. By indirect immunofluorescence, DLB-streptavidin staining was observed as small punctuated spots on the cell surface of menadione-treated KO hepatocytes. Unlike the reported PS externalization, CD95/FasL treatment did not lead to any increase in PE externalization, and iPLA2β deficiency-dependent PE externalization was also not correlated with apoptosis. Thus, constitutive (but not induced) ROS generation in iPLA2β-deficient hepatocytes leads to PE externalization observed only in male mice. Such PE externalization may imply detrimental effects regarding further oxidation of PE fatty acids and the binding with pathogens on the outer leaflets of hepatocyte plasma membrane.
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Affiliation(s)
| | - Monika Langlotz
- Center for Molecular Biology, University of Heidelberg, Heidelberg, Germany
| | | | - Weihong Xu
- Heidelberg University Hospital, Heidelberg, Germany
| | | | | | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University Regensburg, Regensburg, Germany
| | - Uta Merle
- Heidelberg University Hospital, Heidelberg, Germany
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Cheng Y, Gan-Schreier H, Seeßle J, Staffer S, Tuma-Kellner S, Khnykin D, Stremmel W, Merle U, Herrmann T, Chamulitrat W. Methionine- and Choline-Deficient Diet Enhances Adipose Lipolysis and Leptin Release in aP2-Cre Fatp4-Knockout Mice. Mol Nutr Food Res 2020; 64:e2000361. [PMID: 32991778 DOI: 10.1002/mnfr.202000361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/22/2020] [Indexed: 12/11/2022]
Abstract
SCOPE Inadequate intake of choline commonly leads to liver diseases. Methionine- and choline-deficient diets (MCDD) induce fatty liver in mice which is partly mediated by triglyceride (TG) lipolysis in white adipose tissues (WATs). Because Fatp4 knockdown has been shown to increase adipocyte lipolysis in vitro, here, the effects of MCDD on WAT lipolysis in aP2-Cre Fatp4-knockout (Fatp4A-/- ) mice are determined. METHODS AND RESULTS Isolated WATs of Fatp4A-/- mice exposed to MCD medium show an increase in lipolysis, and the strongest effect is noted on glycerol release from subcutaneous fat. Fatp4A-/- mice fed with MCDD for 4 weeks show an increase in serum glycerol, TG, and leptin levels associated with the activation of hormone-sensitive lipase in subcutaneous fat. Chow-fed Fatp4A-/- mice also show an increase in serum leptin and very-low-density lipoproteins as well as liver phosphatidylcholine and sphingomyelin levels. Both chow- and MCDD-fed Fatp4A-/- mice show a decrease in serum ketone and WAT sphingomyelin levels which supports a metabolic shift to TG for subsequent WAT lipolysis CONCLUSIONS: Adipose Fatp4 deficiency leads to TG lipolysis and leptin release, which are exaggerated by MCDD. The data imply hyperlipidemia risk by a low dietary choline intake and gene mutations that increase adipose TG levels.
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Affiliation(s)
- Yuting Cheng
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Hongying Gan-Schreier
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Jessica Seeßle
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Simone Staffer
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Denis Khnykin
- Department of Pathology and Center for Immune Regulation, Rikshospitalet University Hospital, 0424, Oslo, Norway
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Uta Merle
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Thomas Herrmann
- Westkuesten Hospital, Esmarchstraße 50, 25746, Heide, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
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Zhu X, Gan-Schreier H, Otto AC, Cheng Y, Staffer S, Tuma-Kellner S, Ganzha A, Liebisch G, Chamulitrat W. iPla2β deficiency in mice fed with MCD diet does not correct the defect of phospholipid remodeling but attenuates hepatocellular injury via an inhibition of lipid uptake genes. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:677-687. [PMID: 30735854 DOI: 10.1016/j.bbalip.2019.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 02/01/2019] [Accepted: 02/03/2019] [Indexed: 12/19/2022]
Abstract
Group VIA calcium-independent phospholipase A2 (iPla2β) is among modifier genes of non-alcoholic fatty liver disease which leads to non-alcoholic steatohepatitis (NASH). Consistently, iPla2β deletion protects hepatic steatosis and obesity in genetic ob/ob and obese mice chronically fed with high-fat diet by replenishing the loss of hepatic phospholipids (PL). As mouse feeding with methionine- and choline-deficient (MCD) diet is a model of lean NASH, we tested whether iPla2β-null mice could still be protected since PL syntheses are disturbed. MCD-diet feeding of female wild-type for 5 weeks induced hepatic steatosis with a severe reduction of body and visceral fat weights concomitant with a decrease of hepatic phosphatidylcholine. These parameters were not altered in MCD-fed iPla2β-null mice. However, iPla2β deficiency attenuated MCD-induced elevation of serum transaminase activities and hepatic expression of fatty-acid translocase Cd36, fatty-acid binding protein-4, peroxisome-proliferator activated receptorγ, and HDL-uptake scavenger receptor B type 1. The reduction of lipid uptake genes was consistent with a decrease of hepatic esterified and unesterified fatty acids and cholesterol esters. On the contrary, iPla2β deficiency under MCD did not have any effects on inflammasomes and pro-inflammatory markers but exacerbated hepatic expression of myofibroblast α-smooth muscle actin and vimentin. Thus, without any rescue of PL loss, iPla2β inactivation attenuated hepatocellular injury in MCD-induced NASH with a novel mechanism of lipid uptake inhibition. Taken together, we have shown that iPla2β mediates hepatic steatosis and lipotoxicity in hepatocytes in both obese and lean NASH, but elicits exacerbated liver fibrosis in lean NASH likely by affecting other cell types.
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Affiliation(s)
- Xingya Zhu
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Hongying Gan-Schreier
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Ann-Christin Otto
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Yuting Cheng
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Simone Staffer
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Alexandra Ganzha
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
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8
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Otto AC, Gan-Schreier H, Zhu X, Tuma-Kellner S, Staffer S, Ganzha A, Liebisch G, Chamulitrat W. Group VIA phospholipase A2 deficiency in mice chronically fed with high-fat-diet attenuates hepatic steatosis by correcting a defect of phospholipid remodeling. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:662-676. [PMID: 30735855 DOI: 10.1016/j.bbalip.2019.01.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 01/22/2019] [Accepted: 01/25/2019] [Indexed: 12/15/2022]
Abstract
A defect of hepatic remodeling of phospholipids (PL) is seen in non-alcoholic fatty liver disease and steatohepatitis (NASH) indicating pivotal role of PL metabolism in this disease. The deletion of group VIA calcium-independent phospholipase A2 (iPla2β) protects ob/ob mice from hepatic steatosis (BBAlip 1861, 2016, 440-461), however its role in high-fat diet (HFD)-induced NASH is still elusive. Here, wild-type and iPla2β-null mice were subjected to chronic feeding with HFD for 6 months. We showed that protection was observed in iPla2β-null mice with an attenuation of diet-induced body and liver-weight gains, liver enzymes, serum free fatty acids as well as hepatic TG and steatosis scores. iPla2β deficiency under HFD attenuated the levels of 1-stearoyl lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), and lysophosphatidylinositol (LPI) as well as elevation of hepatic arachidonate, arachidonate-containing cholesterol esters and prostaglandin E2. More importantly, this deficiency rescued a defect in PL remodeling and attenuated the ratio of saturated and unsaturated PL. The protection by iPla2β deficiency was not observed during short-term HFD feeding of 3 or 5 weeks which showed no PL remodeling defect. In addition to PC/PE, this deficiency reversed the suppression of PC/PI and PE/PI among monounsaturated PL. However, this deficiency did not modulate hepatic PL contents and PL ratios in ER fractions, ER stress, fibrosis, and inflammation markers. Hence, iPla2β inactivation protected mice against hepatic steatosis and obesity during chronic dietary NASH by correcting PL remodeling defect and PI composition relative to PC and PE.
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Affiliation(s)
- Ann-Christin Otto
- Department of Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Hongying Gan-Schreier
- Department of Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Xingya Zhu
- Department of Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Simone Staffer
- Department of Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Alexandra Ganzha
- Institute of Clinical Chemistry and Laboratory Medicine, University Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
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9
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Döring S, Seeßle J, Gan-Schreier H, Javaheri B, Jiao L, Cheng Y, Tuma-Kellner S, Liebisch G, Herrmann T, Stremmel W, Chamulitrat W. Elevation of blood lipids in hepatocyte-specific fatty acid transport 4-deficient mice fed with high glucose diets. Mol Genet Metab 2019; 126:30-38. [PMID: 30497809 DOI: 10.1016/j.ymgme.2018.11.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/12/2018] [Accepted: 11/17/2018] [Indexed: 11/20/2022]
Abstract
Fatty acid transport protein4 (FATP4) is upregulated in acquired and central obesity and its polymorphisms are associated with blood lipids and insulin resistance. Patients with FATP4 mutations and mice with global FATP4 deletion exhibit skin abnormalities characterized as ischthyosis prematurity syndrome (IPS). Cumulating data have shown that an absence of FATP4 increases the levels of cellular triglycerides (TG). However, FATP4 role and consequent lipid and TG metabolism in the hepatocyte is still elusive. Here, hepatocyte-specific FATP4 deficient (Fatp4L-/-) mice were generated. When fed with chow, these mutant mice displayed no phenotypes regarding blood lipids. However when fed low-fat/high-sugar (HS) or high-fat/high-sugar (HFS) for 12 weeks, Fatp4L-/- mice showed a significant increase of plasma TG, free fatty acids and glycerol when compared with diet-fed control mice. Interestingly, Fatp4L-/- mice under HS diet had lower body and liver weights and they were not protected from HFS-induced body weight gain and hepatic steatosis. Male mutant mice were more sensitive to HFS diet than female mutant mice. Glucose intolerance was observed only in female Fatp4L-/- mice fed with HS diet. Lipidomics analyses revealed that hepatic phospholipids were not disturbed in mutant mice under both diets. Thus, hepatic FATP4 deletion rendered an increase of blood lipids including glycerol indicating a preferential fatty-acid channeling to TG pools that are specifically available for lipolysis. Our results imply a possible risk of hyperlipidemia as a result of abnormal metabolism in liver in IPS patients with FATP4 mutations who consume high-sugar diets.
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Affiliation(s)
- Stephan Döring
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Jessica Seeßle
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Hongying Gan-Schreier
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Bahador Javaheri
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Li Jiao
- Institute of Medical Biology, Chinese Academy of Medical Sciences, Peking Union Medical College, Kunming, Yunnan 650118, China
| | - Yuting Cheng
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Thomas Herrmann
- Westkuesten Hospital, Esmarchstraße 50, 25746 Heide, Germany
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
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10
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Jiao L, Gan-Schreier H, Zhu X, Wei W, Tuma-Kellner S, Liebisch G, Stremmel W, Chamulitrat W. Ageing sensitized by iPLA 2β deficiency induces liver fibrosis and intestinal atrophy involving suppression of homeostatic genes and alteration of intestinal lipids and bile acids. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1520-1533. [PMID: 28888832 DOI: 10.1016/j.bbalip.2017.09.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 08/28/2017] [Accepted: 09/05/2017] [Indexed: 01/06/2023]
Abstract
Ageing is a major risk factor for various forms of liver and gastrointestinal (GI) disease and genetic background may contribute to the pathogenesis of these diseases. Group VIA phospholipase A2 or iPLA2β is a homeostatic PLA2 by playing a role in phospholipid metabolism and remodeling. Global iPLA2β-/- mice exhibit aged-dependent phenotypes with body weight loss and abnormalities in the bone and brain. We have previously reported the abnormalities in these mutant mice showing susceptibility for chemical-induced liver injury and colitis. We hypothesize that iPLA2β deficiency may sensitize with ageing for an induction of GI injury. Male wild-type and iPLA2β-/- mice at 4 and 20-22months of age were studied. Aged, but not young, iPLA2β-/-mice showed increased hepatic fibrosis and biliary ductular expansion as well as severe intestinal atrophy associated with increased apoptosis, pro-inflammation, disrupted tight junction, and reduced number of mucin-containing globlet cells. This damage was associated with decreased expression of intestinal endoplasmic stress XBP1 and its regulator HNF1α, FATP4, ACSL5, bile-acid transport genes as well as nuclear receptors LXRα and FXR. By LC/MS-MS profiling, iPLA2β deficiency in aged mice caused an increase of intestinal arachidonate-containing phospholipids concomitant with a decrease in ceramides. By the suppression of intestinal FXR/FGF-15 signaling, hepatic bile-acid synthesis gene expression was increased leading to an elevation of secondary and hydrophobic bile acids in liver, bile, and intestine. In conclusions, ageing sensitized by iPLA2β deficiency caused a decline of key intestinal homeostatic genes resulting in the development of GI disease in a gut-to-liver manner.
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Affiliation(s)
- Li Jiao
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany; Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, Yunnan 650118, China
| | - Hongying Gan-Schreier
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Xingya Zhu
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Wang Wei
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany.
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Otto AC, Gan-Schreier H, Zhu X, Tuma-Kellner S, Liebisch G, Stremmel W, Chamulitrat W. iPLA2beta deficiency protects mice from diet-induced obesity and steatosis by replenishing the loss of hepatic phospholipids containing unsaturated fatty acids. Z Gastroenterol 2016. [DOI: 10.1055/s-0036-1597444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- AC Otto
- University Heidelberg, Department of Internal Medicine IV, Heidelberg, Germany
| | - H Gan-Schreier
- University Heidelberg, Department of Internal Medicine IV, Heidelberg, Germany
| | - X Zhu
- University Heidelberg, Department of Internal Medicine IV, Heidelberg, Germany
| | - S Tuma-Kellner
- University Heidelberg, Department of Internal Medicine IV, Heidelberg, Germany
| | - G Liebisch
- University Regensburg, Institute of Clinical Chemistry and Laboratory Medicine, Regensburg, Germany
| | - W Stremmel
- University Heidelberg, Department of Internal Medicine IV, Heidelberg, Germany
| | - W Chamulitrat
- University Heidelberg, Department of Internal Medicine IV, Heidelberg, Germany
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12
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Deng X, Wang J, Jiao L, Utaipan T, Tuma-Kellner S, Schmitz G, Liebisch G, Stremmel W, Chamulitrat W. iPLA2β deficiency attenuates obesity and hepatic steatosis in ob/ob mice through hepatic fatty-acyl phospholipid remodeling. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:449-61. [PMID: 26873633 DOI: 10.1016/j.bbalip.2016.02.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 02/01/2016] [Accepted: 02/06/2016] [Indexed: 01/12/2023]
Abstract
PLA2G6 or GVIA calcium-independent PLA2 (iPLA2β) is identified as one of the NAFLD modifier genes in humans, and thought to be a target for NAFLD therapy. iPLA2β is known to play a house-keeping role in phospholipid metabolism and remodeling. However, its role in NAFLD pathogenesis has not been supported by results obtained from high-fat feeding of iPLA2β-null (PKO) mice. Unlike livers of human NAFLD and genetically obese rodents, fatty liver induced by high-fat diet is not associated with depletion of hepatic phospholipids. We therefore tested whether iPLA2β could regulate obesity and hepatic steatosis in leptin-deficient mice by cross-breeding PKO with ob/ob mice to generate ob/ob-PKO mice. Here we observed an improvement in ob/ob-PKO mice with significant reduction in serum enzymes, lipids, glucose, insulin as well as improved glucose tolerance, and reduction in islet hyperplasia. The improvement in hepatic steatosis measured by liver triglycerides, fatty acids and cholesterol esters was associated with decreased expression of PPARγ and de novo lipogenesis genes, and the reversal of β-oxidation gene expression. Notably, ob/ob livers contained depleted levels of lysophospholipids and phospholipids, and iPLA2β deficiency in ob/ob-PKO livers lowers the former, but replenished the latter particularly phosphatidylethanolamine (PE) and phosphatidylcholine (PC) that contained arachidonic (AA) and docosahexaenoic (DHA) acids. Compared with WT livers, PKO livers also contained increased PE and PC containing AA and DHA. Thus, iPLA2β deficiency protected against obesity and ob/ob fatty liver which was associated with hepatic fatty-acyl phospholipid remodeling. Our results support the deleterious role of iPLA2β in severe obesity associated NAFLD.
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Affiliation(s)
- Xiuling Deng
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022 Wuhan, China
| | - Jiliang Wang
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Li Jiao
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Tanyarath Utaipan
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Gerd Schmitz
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University of Heidelberg Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
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13
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Inhoffen J, Tuma-Kellner S, Straub B, Stremmel W, Chamulitrat W. Deficiency of iPLA₂β Primes Immune Cells for Proinflammation: Potential Involvement in Age-Related Mesenteric Lymph Node Lymphoma. Cancers (Basel) 2015; 7:2427-42. [PMID: 26690222 PMCID: PMC4695901 DOI: 10.3390/cancers7040901] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/26/2015] [Accepted: 12/01/2015] [Indexed: 12/12/2022] Open
Abstract
Proinflammation can predispose the body to autoimmunity and cancer. We have reported that iPLA2β−/− mice are susceptible to autoimmune hepatitis and colitis. Here we determined whether cytokine release by immune cells could be affected by iPLA2β deficiency alone or combined with CD95/FasL-antibody treatment in vivo. We also determined whether cancer risk could be increased in aged mutant mice. Immune cells were isolated from 3-month old male WT and iPLA2β−/− mice, and some were injected with anti-CD95/FasL antibody for 6 h. Kupffer cells (KC) or splenocytes and liver lymphocytes were stimulated in vitro by lipopolysaccharide or concanavalinA, respectively. Whole-body iPLA2β deficiency caused increased apoptosis in liver, spleen, and mesenteric lymph node (MLN). KC from mutant mice showed suppressed release of TNFα and IL-6, while their splenocytes secreted increased levels of IFNγ and IL-17a. Upon CD95/FasL activation, the mutant KC in turn showed exaggerated cytokine release, this was accompanied by an increased release of IFNγ and IL-17a by liver lymphocytes. Aged iPLA2β−/− mice did not show follicular MLN lymphoma commonly seen in aged C57/BL6 mice. Thus, iPLA2β deficiency renders M1- and Th1/Th17-proinflammation potentially leading to a reduction in age-related MLN lymphoma during aging.
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Affiliation(s)
- Johannes Inhoffen
- Department of Internal Medicine IV, University Heidelberg Hospital, 69120 Heidelberg, Germany.
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University Heidelberg Hospital, 69120 Heidelberg, Germany.
| | - Beate Straub
- Pathology Institute of Medical Faculty Heidelberg, 69120 Heidelberg, Germany.
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, University Heidelberg Hospital, 69120 Heidelberg, Germany.
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University Heidelberg Hospital, 69120 Heidelberg, Germany.
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14
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Jiao L, Gan-Schreier H, Tuma-Kellner S, Stremmel W, Chamulitrat W. Sensitization to autoimmune hepatitis in group VIA calcium-independent phospholipase A2-null mice led to duodenal villous atrophy with apoptosis, goblet cell hyperplasia and leaked bile acids. Biochim Biophys Acta Mol Basis Dis 2015; 1852:1646-57. [PMID: 25957555 DOI: 10.1016/j.bbadis.2015.04.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 04/27/2015] [Accepted: 04/28/2015] [Indexed: 12/12/2022]
Abstract
Chronic bowel disease can co-exist with severe autoimmune hepatitis (AIH) in an absence of primary sclerosing cholangitis. Genetic background may contribute to this overlap syndrome. We previously have shown that the deficiency of iPLA2β causes an accumulation of hepatocyte apoptosis, and renders susceptibility for acute liver injury. We here tested whether AIH induction in iPLA2β-null mice could result in intestinal injury, and whether bile acid metabolism was altered. Control wild-type (WT) and female iPLA2β-null (iPLA2β(-/-)) mice were intravenously injected with 10mg/kg concanavalinA (ConA) or saline for 24h. ConA treatment of iPLA2β(-/-) mice caused massive liver injury with increased liver enzymes, fibrosis, and necrosis. While not affecting WT mice, ConA treatment of iPLA2β(-/-) mice caused severe duodenal villous atrophy concomitant with increased apoptosis, cell proliferation, globlet cell hyperplasia, and endotoxin leakage into portal vein indicating a disruption of intestinal barrier. With the greater extent than in WT mice, ConA treatment of iPLA2β(-/-) mice increased jejunal expression of innate response cytokines CD14, TNF-α, IL-6, and SOCS3 as well as chemokines CCL2 and the CCL3 receptor CCR5. iPLA2β deficiency in response to ConA-induced AIH caused a significant decrease in hepatic and biliary bile acids, and this was associated with suppression of hepatic Cyp7A1, Ntcp and ABCB11/Bsep and upregulation of intestinal FXR/FGF15 mRNA expression. The suppression of hepatic Ntcp expression together with the loss of intestinal barrier could account for the observed bile acid leakage into peripheral blood. Thus, enteropathy may result from acute AIH in a susceptible host such as iPLA2β deficiency.
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Affiliation(s)
- Li Jiao
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany; Department of Toxicology, School of Public Health, Jilin University, Changchun, China
| | - Hongying Gan-Schreier
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Sabine Tuma-Kellner
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Wolfgang Stremmel
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany
| | - Walee Chamulitrat
- Department of Internal Medicine IV, University of Heidelberg Hospital, Heidelberg, Germany.
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