*Purpose: Nonalcoholic steatohepatitis (NASH) is an emerging global epidemic projected to become the leading indication for liver transplantation (LT). Although recent studies focus on the utilization of steatotic livers as marginal grafts, little is known as to whether and how the recipient steatosis may affect LT outcomes. It was shown that mice with severe hepatic steatosis were highly susceptible to neutrophil extracellular trap-related cell death (NETosis) and subsequent thrombosis formation. The present study was aimed to assess whether the severity of steatosis in prospective mouse recipients may influence the course of donor LT.

*Methods: Four-week old WT mice (C57/BL6) were fed with normal diet (ND) or high fat diet (HFD) for 4 or 12 weeks. Four-week HFD feeding resulted in the development of microvesicular steatosis (<30% lipid droplet), while 12 week HFD feeding led to classic macrovesicular steatosis (>60%). Donor WT livers were then transplanted, after cold storage (4oC/90min), to distinct groups of syngeneic: 1/ ND-WT, 2/ HFD (4w)-WT or 3/ HFD (12W)-WT recipients. LTs samples collected at 6h and 24h were analyzed by qRT-PCR, western blotting and immunohistochemistry.

*Results: Mouse recipients in HFD (12w) group had significantly higher post-LT transaminase release/enhanced pro-inflammatory cytokine/chemokine profiles at 6h post-LT, as compared to ND or HFD (4w) groups. Unexpectedly, HFD (12w)-fed recipients failed to survive longer than 2 days post-LT, despite all recipients surviving >14days in ND and HFD (4w)-fed groups. Western blot analysis revealed that the expression of LC3B (autophagy marker) was significantly impaired, while VCAM-1 and CD62P (endothelial damage markers) were significantly upregulated in HFD (12w) group at 24h post-LT. Immunohistochemistry analysis of CD42b, Ly6G, and Histone H3 expression/levels showed NET related platelet thrombosis was profoundly augmented in HFD (12w)-fed recipients. These results indicate that mouse recipients suffering from severe steatosis prior to liver transplantation were highly susceptible to LT-related hepatic IR-stress/injury.

*Conclusions: This study documents that severely steatotic mouse recipients even when transplanted with healthy donor livers may experience NETosis-related thrombosis, accompanied by poor post-LT outcomes.

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