Interleukin-1ß Attenuates Expression of Augmenter of Liver Regeneration (ALR) by Regulating HNF4α Independent of c-Jun.
Int J Mol Sci
; 24(9)2023 Apr 30.
Article
en En
| MEDLINE
| ID: mdl-37175814
ABSTRACT
Inflammasomes and innate immune cells have been shown to contribute to liver injury, thereby activating Kupffer cells, which release several cytokines, including IL-6, IL-1ß, and TNFα. Augmenter of liver regeneration (ALR) is a hepatotropic co-mitogen that was found to have anti-oxidative and anti-apoptotic properties and to attenuate experimental non-alcoholic fatty liver disease (NAFLD) and cholestasis. Additionally, hepatic ALR expression is diminished in patients with NAFLD or cholestasis, but less is known about the mechanisms of its regulation under these conditions. Therefore, we aimed to investigate the role of IL-1ß in ALR expression and to elucidate the molecular mechanism of this regulation in vitro. We found that ALR promoter activity and mRNA and protein expression were reduced upon treatment with IL-1ß. Early growth response protein-1 (Egr-1), an ALR inducer, was induced by IL-1ß but could not activate ALR expression, which may be attributed to reduced Egr-1 binding to the ALR promoter. The expression and nuclear localization of hepatocyte nuclear factor 4 α (HNF4α), another ALR-inducing transcription factor, was reduced by IL-1ß. Interestingly, c-Jun, a potential regulator of ALR and HNF4α, showed increased nuclear phosphorylation levels upon IL-1ß treatment but did not change the expression of ALR or HNF4α. In conclusion, this study offers evidence regarding the regulation of anti-apoptotic and anti-oxidative ALR by IL-1ß through reduced Egr-1 promoter binding and diminished HNF4α expression independent of c-Jun activation. Low ALR tissue levels in NAFLD and cholestatic liver injury may be caused by IL-1ß and contribute to disease progression.
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Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Colestasis
/
Enfermedad del Hígado Graso no Alcohólico
Límite:
Humans
Idioma:
En
Revista:
Int J Mol Sci
Año:
2023
Tipo del documento:
Article
País de afiliación:
Alemania