title: Dose-Dependent Metabolic Reprogramming and Differential Gene Expression in TCDD-Elicited Hepatic Fibrosis.
abstract: We have previously shown that in response to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-elicited NAFLD progression, central carbon, glutaminolysis, and serine/folate metabolism are reprogrammed to support NADPH production and ROS defenses. To further investigate underlying dose-dependent responses associated with TCDD-induced fibrosis, female C57BL/6 mice were gavaged with TCDD every 4 days (d) for 28 d or 92 d. RNA-Seq, ChIP-Seq (2 h), and 28 d metabolomic (urine, serum, and hepatic extract) analyses were conducted with complementary serum marker assessments at 92 d. Additional vehicle and 30 µg/kg treatment groups were allowed to recover for 36 d following the 92-d treatment regimen to examine recovery from TCDD-elicited fibrosis. Histopathology revealed dose-dependent increases in hepatic fat accumulation, inflammation, and periportal collagen deposition at 92 days, with increased fibrotic severity in the recovery group. Serum proinflammatory and profibrotic interleukins-1β, -2, -4, -6, and -10, as well as TNF-α and IFN-γ, exhibited dose-dependent induction. An increase in glucose tolerance was observed with a concomitant 3.0-fold decrease in hepatic glycogen linked to increased ascorbic acid biosynthesis and proline metabolism, consistent with increased fibrosis. RNA-Seq identified differential expression of numerous matrisome genes including an 8.8-fold increase in Tgfb2 indicating myofibroblast activation. Further analysis suggests reprogramming of glycogen, ascorbic acid, and amino acid metabolism in support of collagen deposition and the use of proline as a substrate for ATP production via the proline cycle. In summary, we demonstrate that glycogen, ascorbic acid, and amino acid metabolism are also reorganized to support remodeling of the extracellular matrix, progressing to hepatic fibrosis in response to chronic injury from TCDD.
authors: Biochemistry & Molecular Biology.|Institute for Integrative Toxicology.
authors: Rance
authors: R
authors: Nault
authors: Biochemistry & Molecular Biology.|Institute for Integrative Toxicology.
authors: Kelly A
authors: KA
authors: Fader
authors: Biochemistry & Molecular Biology.
authors: Dustin A
authors: DA
authors: Ammendolia
authors: Biochemistry & Molecular Biology.|Institute for Integrative Toxicology.
authors: Peter
authors: P
authors: Dornbos
authors: Wellington Laboratories, Inc., Guelph, Ontario, Canada.
authors: Dave
authors: D
authors: Potter
authors: Wellington Laboratories, Inc., Guelph, Ontario, Canada.
authors: Bonnie
authors: B
authors: Sharratt
authors: Pathology & Diagnostic Investigation, Michigan State University, East Lansing, Michigan.
authors: Kazuyoshi
authors: K
authors: Kumagai
authors: Institute for Integrative Toxicology.|Pathology & Diagnostic Investigation, Michigan State University, East Lansing, Michigan.
authors: Jack R
authors: JR
authors: Harkema
authors: Biochemistry & Molecular Biology.
authors: Sophia Y
authors: SY
authors: Lunt
authors: Department of Nutrition, University of Oslo, Oslo 0316, Norway.
authors: Jason
authors: J
authors: Matthews
authors: Biochemistry & Molecular Biology; tzachare@msu.edu.|Institute for Integrative Toxicology.
authors: Tim
authors: T
authors: Zacharewski
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D065150:Cellular Reprogramming / Q000187:drug effects*; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D003094:Collagen / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects*; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D018836:Inflammation Mediators / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008103:Liver Cirrhosis / Q000139:chemically induced* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008810:Mice, Inbred C57BL; D065626:Non-alcoholic Fatty Liver Disease / Q000139:chemically induced* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D011392:Proline / Q000378:metabolism; D013997:Time Factors; D059467:Transcriptome / Q000187:drug effects*
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D000072317:Polychlorinated Dibenzodioxins; D006003:Glycogen; D003094:Collagen; D011392:Proline; D005947:Glucose; D001205:Ascorbic Acid
keywords: AhR.; NAFLD; RNA-Seq; matrisome; metabolomic