title: Lithocholic acid disrupts phospholipid and sphingolipid homeostasis leading to cholestasis in mice.
abstract: Lithocholic acid (LCA) is an endogenous compound associated with hepatic toxicity during cholestasis. LCA exposure in mice resulted in decreased serum lysophosphatidylcholine (LPC) and sphingomyelin levels due to elevated lysophosphatidylcholine acyltransferase (LPCAT) and sphingomyelin phosphodiesterase (SMPD) expression. Global metabolome analysis indicated significant decreases in serum palmitoyl-, stearoyl-, oleoyl-, and linoleoyl-LPC levels after LCA exposure. LCA treatment also resulted in decreased serum sphingomyelin levels and increased hepatic ceramide levels, and induction of LPCAT and SMPD messenger RNAs (mRNAs). Transforming growth factor-β (TGF-β) induced Lpcat2/4 and Smpd3 gene expression in primary hepatocytes and the induction was diminished by pretreatment with the SMAD3 inhibitor SIS3. Furthermore, alteration of the LPCs and Lpcat1/2/4 and Smpd3 expression was attenuated in LCA-treated farnesoid X receptor-null mice that are resistant to LCA-induced intrahepatic cholestasis.
  
  
  CONCLUSIONS
  This study revealed that LCA induced disruption of phospholipid/sphingolipid homeostasis through TGF-β signaling and that serum LPC is a biomarker for biliary injury.
authors.affiliation: Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Matsubara
authors.forename: Naoki
authors.initials: N
authors.lastname: Tanaka
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Patterson
authors.forename: Joo-Youn
authors.initials: JY
authors.lastname: Cho
authors.forename: Kristopher W
authors.initials: KW
authors.lastname: Krausz
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Gonzalez
mesh_terms: D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000096:biosynthesis; D000818:Animals; D002518:Ceramides / Q000096:biosynthesis; D002779:Cholestasis; D005260:Female; D006706:Homeostasis / Q000187:drug effects; D008095:Lithocholic Acid / Q000097:blood / Q000633:toxicity*; D008244:Lysophosphatidylcholines / Q000097:blood; D055442:Metabolome; D051379:Mice; D008810:Mice, Inbred C57BL; D010743:Phospholipids / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013107:Sphingolipids / Q000378:metabolism; D013108:Sphingomyelin Phosphodiesterase / Q000096:biosynthesis; D013109:Sphingomyelins / Q000097:blood; D016212:Transforming Growth Factor beta / Q000502:physiology
chemical_list: D002518:Ceramides; D008244:Lysophosphatidylcholines; D010743:Phospholipids; D012333:RNA, Messenger; D013107:Sphingolipids; D013109:Sphingomyelins; D016212:Transforming Growth Factor beta; D008095:Lithocholic Acid; D008243:1-Acylglycerophosphocholine O-Acyltransferase; C491483:Smpd3 protein, mouse; D013108:Sphingomyelin Phosphodiesterase