C6orf120 gene knockout in rats mitigates concanavalin A­induced autoimmune hepatitis via regulating NKT cells.

OBJECTIVE: To elucidate the role of the functional unknown gene C6orf120 in the pathogenesis of AIH and its mechanism of action, using C6orf120 knockout rats. METHODS: An autoimmune hepatitis model was established with 35 mg/kg intravenous injection of concanavalin A (Con A) in C6orf120-knockout (C6orf120-/-) and wild-type (WT) rats. Rats were sacrificed after administering Con A for 0, 12, and 24 h. The peripheral blood, liver, spleen, and mesenteric lymph nodes were collected for follow-up studies. RESULTS: C6orf120 knockout significantly decreased the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and improved the histological damage in Con A-induced autoimmune liver injury.Loss of C6orf120 function significantly increased the frequency of CD3+ CD161+ NKT cells in the peripheral blood, liver, and spleen; downregulated the expression of CD314 (NKG2D) in the liver, spleen, and mesenteric lymph nodes; reduced the expression of inflammatory cytokines and chemokines; and suppressed the mRNA and protein expression of Fas and FasL in the liver. Additionally, C6orf120 knockout significantly downregulated the expression of p-JAK1, p-JAK2, p-STAT1, and p-STAT3 in liver tissue. CONCLUSION: The protective effect of C6orf120 knockout against Con A-induced hepatitis may be due to the inhibition of NKT cell activation, restriction of cytokine and chemokine activities, inhibition of JAK-STAT and Fas/FasL signaling pathway activation, and reduction in liver inflammation and hepatocyte apoptosis.

Deletion of the C6orf120 gene with unknown function ameliorates autoimmune hepatitis induced by concanavalin A.

The present study was conducted to characterize the C6orf120 gene, by using C6orf120 gene-deleted rats (C6orf120-/-), to determine its role in the development and severity of autoimmune hepatitis induced by concanavalin A (Con A), as well as the underlying mechanisms. We found that following Con A injection, C6orf120-/- rats were less susceptible to developing autoimmune hepatitis with low levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) post challenge. Additionally, C6orf120 deficiency increased the frequency of cluster of differentiation (CD)4+ CD25+ Forkhead box P3+ regulatory T cells (Tregs) among intrahepatic lymphocytes, splenocytes, peripheral blood mononuclear cells, and CD4+ T in vitro. Moreover, C6orf120 deficiency downregulated interleukin (IL)-1ß, IL-6, tumor necrosis factor alpha-α, interferon-γ and IL-17a secretion in the plasma and liver tissues. Our results indicated that the C6orf120 gene-deleted rats were less susceptible to Con A-induced autoimmune hepatitis, which may be partly related to the increased frequency of Tregs and inhibited secretion of inflammatory cytokines.

C6orf120 gene deficiency may be vulnerable to carbon tetrachloride induced acute hepatic injury in rats.

Introduction: The function of the C6orf120 gene, which encodes an N-glycosylated protein, remains unknown. The study was performed to characterize the utility of the C6orf120 gene in carbon tetrachloride-induced acute liver injury and to elucidate the potential underlying mechanisms by establishing a C6orf120 gene-knockout (C6orf120-/-) rat model. Material and methods: C6orf120-/- and wild-type (WT) rats were intraperitoneally administered with CCl4 (1 : 1 v/v in olive oil, 2 µl/g). Rats were sacrificed 24 h after CCl4 administration. Liver tissues were collected for H&E, IHC, qRT-PCR, and Western blot analysis. Results: C6orf120 gene deficiency may be vulnerable to CCl4-induced acute liver injury in rats as indicated by the high levels of alanine aminotransferase (WT: 388.7 ±55.96 vs. C6orf120-/-: 915.9 ±118.8, p < 0.001) and greater degree of pathological damage. Quantitative reverse transcription polymerase chain reaction showed that the mRNA levels of inflammation-associated cytokines, such as interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α, in liver tissues were increased in C6orf120-/- rats compared with those in WT rats. Moreover, western blot showed that the protein expression of cytokines nucleotide-binding oligomerization domain leucine rich repeat and pyrin domain containing 3 (NLRP3), caspase-1, IL-1ß, nuclear factor-κB, c-Jun N-terminal kinases, and Bax were increased in C6orf120-/- rats compared with those in WT rats. Conclusions: C6orf120-/- rats were susceptible to CCl4-induced liver injury, which may be related to NLRP3 inflammasome and JNK signaling pathway activation.