studies

868A AASLD ABSTRACTS HEPATOLOGY, October, 2015
dramatically reduced hepatic triglycerides, decreased hepatic
cholesterol amount and normalized serum liver enzymes compared
to ethanol-fed WT mice. Our studies revealed that genetically
ablation of mitoNEET in mice alleviated alcoholic fatty
liver injury by way of turning on multiples signaling pathways,
including stimulated ileal fibroblast growth factor 15 (FGF15)
synthesis, activated a pre-mRNA splicing regulator SLU7, and
suppressed hepatic lipin-1-medaited phosphatidate phosphatase
(PAP) activity. Altogether, our novel findings suggest that
mitoNEET plays a pivotal role in development and progression
of alcoholic fatty liver injury in mice. Hence, Pharmacological
or nutritional modulation of mitoNEET may be beneficial for
the prevention or treatment of human alcoholic steatosis/steatohepatitis.
Disclosures:
The following authors have nothing to disclose: Alvin Jogasuria, Werner J.
Geldenhuys, Jiayou Wang, Xudong Hu, Kwangwon Lee, Prabodh Sadana,
Jiashin Wu, Min You
1339
Cross talk between hepatocytes and macrophages in
Alcoholic Liver Disease: which language do they use?
Veronica Marin 1 , Kyle L. Poulsen 2 , Laura E. Nagy 2,3 , Claudio
Tiribelli 1,4 , Natalia Rosso 1 ; 1 Fondazione Italiana Fegato, Trieste,
Italy; 2 Department of Pathobiology, Cleveland Clinic, Cleveland,
OH; 3 Department of Molecular Medicine, Case Western Reserve
University, Cleveland, OH; 4 Department of Medical Sciences, University
of Trieste, Trieste, Italy
Macrophage migration inhibitory factor (MIF) is a key cytokine
involved several inflammatory diseases that, depending on
the target cell and inammatory context, can engage different
receptors. It has been reported that interaction between MIF
and CD74 could exert hepatoprotective effects. In the present
study, we explored specifically MIF and CD74 expression in
hepatocytes and macrophage in response to ethanol (EtOH)
exposure. Co-culture of hepatocytes (HuH7) and differentiated
macrophages (THP1+100nM PMA) were exposed to 25mM
EtOH for 24h; monocultures of each cell type were used as
controls (CTRL). Gene expression of MIF, CD74 and TNF-α
was analyzed by real time PCR. The amount of MIF and TNF-α
released in the cultured-media was quantified by ELISA. CD74
protein expression was detected with anti-human CD74-FITC
antibody by flow cytometry. In hepatocytes monoculture, EtOH
induces an up-regulation of TNF-α and MIF mRNA expression,
not translated in cytokines’ release. Interestingly, CD74 expression
(gene and protein) was barely detected in these cells.
On the other hand, in macrophages monoculture EtOH did
not induce relevant changes in any of the parameters under
study. When co-cultured, EtOH increased MIF release (with
no changes at mRNA level).both in hepatocytes and macrophages.
Interestingly, co-cultured hepatocytes showed a significant
up-regulation of CD74 mRNA expression compared with
monoculture CTRL and the same trend was also confirmed at
CD74 protein level in both co-cultured cell types. Regarding
TNF-α even if mRNA was dramatically upregulated its release
was unchanged in hepatocytes and significantly decreased in
macrophages. In conclusion, these data clearly demonstrate
that there is a differential cellular response to EtOH when
hepatocytes and macrophages are cultured together. We
hypothesize that EtOH-challenged hepatocytes (in presence
of macrophages) might be the main source of MIF production
and that CD74 play a determinant role in this mechanism. The
reduction in macrophages TNF-α release lead to the speculation
that in this model MIF through CD74 interaction might
exert hepatoprotective effects.
Table 1- Summary of the obtained data both in monoculture and
co-culture system in response to ethanol exposure
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