Zinc finger protein A20 protects rats against chronic liver allograft dysfunction

AIM： To investigate the effect of zinc finger protein A20 on chronic liver allograft dysfunction in rats. METHODS： AIIogeneic liver transplantation from DA rats to Lewis rats was performed. Chronic liver allograft dysfunction was induced in the rats by administering low-dose tacrolimus at postoperative day （POD） 5. Hepatic overexpression of A20 was achieved by recom- binant adenovirus （rAd.）-mediated gene transfer ad- ministered intravenously every 10 d starting from POD 10. The recipient rats were injected with physiologi- cal saline, rAdEasy-A20 （1 × 109 pfu/30 g weight） or rAdEasy （1 × 109 pfu/30 g weight） every 10 d through the tail vein for 3 mo starting from POD 10. Liver tissue samples were harvested on POD 30 and POD 60. RESULTS： Liver-transplanted rats treated with only tacrolimus showed chronic allograft dysfunction with severe hepatic fibrosis. A20 overexpression ameliorated the effects on liver function, attenuated liver allograft fibrosis and prolonged the survival of the recipient rats. Treatment with A20 suppressed hepatic protein pro- duction of tumor growth factor （TGF）-β1, interleukin- 113, caspase-8, CD40, CD40L, intercellular adhesion molecule-i, vascular cell adhesion molecule-1 and E-selectin. A20 treatment suppressed liver cell apopto- sis and inhibited nuclear factor-KB activation of Kupffer cells （KCs）, liver sinusoidal endothelial cells （LSECs） and hepatic stellate cells （HSCs）, and it subsequently decreased cytokine mRNA expression in KCs and LSECs and reduced the production of TGF-β1 in HSCs. CONCLUSION： A20 might prevent chronic liver allogra- ft dysfunction by re-establishing functional homeostasis of KCs, LSECs and HSCs.

Chronic lung allograft dysfunction post-lung transplantation:The era of bronchiolitis obliterans syndrome and restrictive allograft syndrome

Chronic lung allograft dysfunction(CLAD)following lung transplantation limits long-term survival considerably.The main reason for this is a lack of knowledge regarding the pathological condition and the establishment of treatment.The consensus statement from the International Society for Heart and Lung Transplantation on CLAD in 2019 classified CLAD into two main phenotypes:Bronchiolitis obliterans syndrome and restrictive allograft syndrome.Along with this clear classification,further exploration of the mechanisms and the development of appropriate prevention and treatment strategies for each phenotype are desired.In this review,we summarize the new definition of CLAD and update and summarize the existing knowledge on the underlying mechanisms of bronchiolitis obliterans syndrome and restrictive allograft syndrome,which have been elucidated from clinicopathological observations and animal experiments worldwide.