Changes in S-adenosylmethionine and GSH homeostasis during endotoxemia in mice

Kwangsuk Ko, Heping Yang, Mazen Noureddin, Ainhoa Iglesia-Ara, Meng Xia, Conrad Wagner, Zigmund Luka, José M. Mato, Shelly C. Lu

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47 Scopus citations


Endotoxemia participates in the pathogenesis of many liver injuries. Lipopolysaccharide (LPS) was shown to inactivate hepatic methionine adenosyltransferase (MAT), the enzyme responsible for S-adenosylmethionine (SAMe) biosynthesis. SAMe treatment was shown to prevent the LPS-induced increase in tumor necrosis factor-α, which may be one of its beneficial effects. SAMe is also an important precursor of glutathione (GSH) and GSH was shown to ameliorate LPS-induced hepatotoxicity. The aims of this work were to examine changes in SAMe and GSH homeostasis during endotoxemia and the effect of SAMe. Mice received SAMe or vehicle pretreatment followed by LPS and were killed up to18 h afterward. Unexpectedly, we found hepatic SAMe level increased 67% following LPS treatment while S-adenosylhomocysteine level fell by 26%, suggesting an increase in SAMe biosynthesis and/or block in transmethylation. The mRNA and protein levels of MAT1A and MAT2A were increased following LPS. However, despite increased MAT1A expression, MAT activity remained inhibited 18 h after LPS. The major methyltransferase that catabolizes hepatic SAMe is glycine N-methyltransferase, whose expression fell by 65% following LPS. Hepatic GSH level fell more than 50% following LPS, coinciding with a comparable fall in the mRNA and protein levels of glutamate-cysteine ligase (GCL) catalytic (GCLC) and modifier subunits (GCLM). SAMe pretreatment prevented the fall in GCLC and attenuated the fall in GCLM expression and GSH level. SAMe pretreatment prevented the LPS-induced increase in plasma alanine transaminases levels but not the LPS-induced increase in hepatic mRNA levels of proinflammatory cytokines. It further enhanced LPS-induced increase in interleukin-10 mRNA level. Taken together, the hepatic response to LPS is to upregulate MAT expression and inhibit SAMe utilization. GSH is markedly depleted largely due to lower expression of GCL. Interestingly, SAMe treatment prevented the fall in GCL and helped to preserve the GSH store and prevent liver injury.

Original languageEnglish
Pages (from-to)1121-1129
Number of pages9
JournalLaboratory Investigation
Issue number10
StatePublished - Oct 2008

Bibliographical note

Funding Information:
This work was supported by NIH Grants DK51719 and DK45334 (to SC Lu), AA13847 and AT-1576 (to SCL and JMM); DK15289 (to CW), PN I + D SAF 2005-00855, HEPADIP-EULSHM-CT-205, and ETORTEK 2005 (to JMM). Ainhoa Iglesias Ara is a recipient of the Postdoctoral Fellowship supported by the CIC bioGUNE, Centro de Investigación Cooperativa en Biosciencías.


  • Glutamate-cysteine ligase
  • Glutathione
  • Glycine N-methyltransferase
  • Lipopolysaccharide
  • Methionine adenosyltransferase
  • S-adenosylmethionine


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