Heterotopic auxiliary rat liver transplantation with flow-regulated portal vein arterialization in acute hepatic failure

Heterotopic Auxiliary Whole Liver Rat Transplant Model Utilizing a Hepaticoureterostomy for Allograft Rejection Studies

Small animal transplant models are indispensable for organ tolerance studies investigating feasible therapeutic interventions in preclinical studies. Rat liver transplantation (LTx) protocols typically use an orthotopic model where the recipients' native liver is removed and replaced with a donor liver. This technically demanding surgical procedure requires advanced micro-surgical skills and is further complicated by lengthy anhepatic and lower body ischemia times. This prompted the development of a less complicated heterotopic method that can be performed faster with no anhepatic or lower body ischemia time, reducing post-surgery stress for the recipient animal. This heterotopic LTx protocol includes two main steps: excising the liver from the donor rat and transplanting the whole liver into the recipient rat. During the excision of the donor liver, the surgeon ligates the supra-hepatic vena cava (SHVC) and hepatic artery (HA). On the recipient side, the surgeon removes the left kidney and positions the donor liver with the portal vein (PV), infra-hepatic vena cava (IHVC), and bile duct facing the renal vessels. Further, the surgeon anastomoses the recipient's renal vein end to end with the IHVC of the liver and arterializes the PV with the renal artery using a stent. A hepaticoureterostomy is utilized for biliary drainage by anastomosing the bile duct to the recipient's ureter, permitting the discharge of bile via the bladder. The average duration of the transplantation was 130 min, cold ischemia duration was around 35 min, and warm ischemia duration was less than 25 min. Hematoxylin and eosin histology of the auxiliary liver from syngeneic transplants showed normal hepatocyte structure with no significant parenchymal alterations 30 days post-transplant. In contrast, 8-day post-transplant allogeneic graft specimens demonstrated extensive lymphocytic infiltration with a Banff Schema rejection activity index score of 9. Therefore, this LTx method facilitates a low morbidity rejection model alternative to orthotopic LTx.

Chinese Herb Jiedu Huayu Granules Inhibiting Immune and Inflammatory Response of Rats with Acute Liver Failure by Regulating the NF-κB Signaling Pathway

Objective

To research the influence of Chinese medicine Jiedu Huayu granules (JDHY) on the immune response and inflammatory response of rats with acute liver failure (ALF) and investigate its related mechanism.

Methods

Rats were randomly divided into 4 groups: control group (n = 6) were injected with the same amount of normal saline; ALF group (n = 10) were injected intraperitoneally with D-GaIN (700 mg/kg) and LPS (10 μg/kg); ALF+JDHY group (n = 10) were given JDHY 57.55 g/kg/d by gavage for 7 days and injected intraperitoneally with D-GaIN/LPS after the last dose; and ALF+BAY group (n = 10) were given BAY 10 mg/kg/d by gavage for 7 days and injected intraperitoneally with D-GaIN/LPS after the last dose. Changes in liver function and coagulation function were examined in rat serum; the pathological varieties of liver tissues were verified by HE staining; immunohistochemistry was utilized to determine the ratio of PCNA and F4/80 in liver tissues; the flow cytometry was applied to determine the ratio of CD4+/CD8+ cells in peripheral blood mononuclear cells (PBMCs); ELISA and qRT-PCR were utilized to check the level of IL-10, IL-6, IL-13, IL-1β, TNF-α, IFN-γ, and CD163 in serum and liver cells. Western blot was adopted to check the expression of apoptotic protein and expression and NF-κB pathway-related protein expression.

Results

JDHY and BAY could decline the expression of AST, ALT, ALP, and TBiL in ALF rat serum significantly (P < 0.01), increase PTA and PLT (P < 0.01), and mitigate liver tissue damage. Besides, JDHY and BAY could reduce the apoptosis and improve the proliferation of the liver cells in rats with ALF; meanwhile, the ratio of CD4+ cells and F4/80 cells was reduced while CD8+ cells were increased (P < 0.01). Further, JDHY and BAY could reduce the level of IFN-γ, IL-6, IL-1β, and TNF-α while increasing the level of IL-10 and IL-13 (P < 0.01). Additionally, the expression of sCD163 in serum and CD163 expression in liver tissues increased (P < 0.01). The result of western blot confirmed that JDHY could inhibit the phosphorylated expression of NF-κB, IKβα, and IKKβ in the ALF rat tissues.

Conclusions

JDHY can upregulate the level of CD163/sCD163 by the NF-κB signaling pathway, thereby regulating immune response, inhibiting inflammatory response, and ultimately improving ALF in the rats.

Surgical Models to Explore Acellular Liver Scaffold Transplantation: Step-by-Step

Acellular liver scaffolds (ALS) have arisen as potential candidates for transplantation. Until now, all reports involving ALS transplantation failed in surgical method descriptions and do not offer support to scientists to reproduce the procedures used in experimental microsurgery to make the results comparable to literature. To overcome the lack of detail information, we described surgical steps details to perform heterotopic and partial orthotopic surgical models to promote ALS transplantation. After preservation and vessel cannulation steps, the liver grafts were decellularized. In addition, ex vivo blood perfusion tests were performed to obtain a successful anticoagulation treatment prior in vivo transplantation. Then, methods of partial liver resection, combination of hand-suture and cuff techniques to complete end-to-end anastomosis between the scaffold and the recipient animal were performed. These procedures which take 30-60 min and were efficient to allow acellular liver scaffold viability and recellularization of different types of cell post-surgery. In conclusion, our methods are practical and simple promising approach that provides the opportunity to investigate ways to achieve sufficient liver function post-transplantation in vivo.

Improved donor liver position selection and revascularization for heterotopic auxiliary liver transplantation with portal vein arterialization

PURPOSE

To establish an animal model of improved donor liver position selection and revascularization for heterotopic auxiliary liver transplantation with portal vein arterialization (HALT-PVA).

METHODS

Sprague-Dawley rats were utilized to establish models. Improved HALT-PVA was conducted for the experimental rat: hepatic common artery of donor liver was end-to-side anastomosed to portal vein which was end-to-side anastomosed to the left common iliac artery of host rat, while the segments of inferior vena cava superior and inferior to the donor liver were end-to-side anastomosed to the inferior vena cava of host rat, respectively. For the control rats, liver transplantations were conducted through end-to-end anastomosis between portal vein of donor liver and stand tube placed in right renal artery of host rat, and end-to-side anastomosis between the inferior vena cava inferior to the donor liver with the inferior vena cava of host rat, while the inferior vena cava superior to the donor liver was stitched up. Besides, hepaticoenterostomy were performed to all rats and survival status were monitored. ALT, AST, TBil and CHE were tested continuously after operation, and pathological examination of liver tissues were performed.

RESULTS

The survival rate was 93.3% (14/15). ALT, AST, TBil and CHE for experimental group showed a rapider recovery of liver functions than controls. Pathological examinations of liver tissues from the experimental-group rats showed better presentation than the control-group rats.

CONCLUSIONS

The improved HALT-PVA better accords with the normal anatomy, with little detriment to implanted liver, and therefore is a good model for HALT-PVA related research.