Effects of modulating M3 muscarinic receptor activity on azoxymethane-induced liver injury in mice

Sandeep Khurana, Ravirajsinh Jadeja, William Twaddell, Kunrong Cheng, Vikrant Rachakonda, Neeraj Saxena, Jean Pierre Raufman

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


Previously, we reported that azoxymethane (AOM)-induced liver injury is robustly exacerbated in M3 muscarinic receptor (M3R)-deficient mice. We used the same mouse model to test the hypothesis that selective pharmacological modulation of M3R activity regulates the liver injury response. Initial experiments confirmed that giving a selective M3R antagonist, darifenacin, to AOM-treated mice mimicked M3R gene ablation. Compared to vehicle controls, mice treated with the M3R antagonist had reduced survival and increased liver nodularity and fibrosis. We next assessed AOM-induced liver injury in mice treated with a selective M3R agonist, pilocarpine. After pilocarpine treatment, stimulation of post-M3R signaling in the liver was evidenced by ERK and AKT activation. In contrast to the damaging effects of the M3R antagonist, administering pilocarpine to AOM-treated mice significantly attenuated hepatic stellate cell activation, collagen deposition, bile ductule proliferation, and liver fibrosis and nodularity. As anticipated from these findings, livers from pilocarpine-treated mice exhibited reduced expression of key players in fibrosis (a1 collagen, a-smooth muscle actin, TGF-b1, PGDF, TGF-b1R, PGDFR) and decreased mRNA levels for molecules that regulate extracellular matrix formation (TIMP-1, TIMP-2, MMP-2, MMP-13). Cleaved caspase-3, nitrotyrosine and BrdU immunostaining provided evidence that pilocarpine treatment reduced hepatocyte apoptosis and oxidative stress, while increasing hepatocyte proliferation. Collectively, these findings identify several downstream mechanisms whereby M3R activation ameliorates toxic liver injury. These novel observations provide a proof-of-principle that selectively stimulating M3R activation to prevent or diminish liver injury is a therapeutic strategy worthy of further investigation.

Original languageEnglish (US)
Pages (from-to)329-338
Number of pages10
JournalBiochemical Pharmacology
Issue number2
StatePublished - 2013
Externally publishedYes


  • Azoxymethane
  • Darifenacin
  • Liver injury
  • Muscarinic receptors
  • Pilocarpine

ASJC Scopus subject areas

  • Biochemistry
  • Pharmacology


Dive into the research topics of 'Effects of modulating M3 muscarinic receptor activity on azoxymethane-induced liver injury in mice'. Together they form a unique fingerprint.

Cite this