Zhishui Chen

Antisense extracellular signal-regulated kinase-2 gene therapy inhibits platelet-derived growth factor-induced proliferation, migration and transforming growth factor-β1 expression in vascular smooth muscle cells and attenuates transplant vasculopathy

Platelet‐derived growth factor‐BB (PDGF‐BB) enables vascular smooth muscle cells (VSMCs) to proliferate, migrate and secrete connective tissue matrix, which are critical events in transplant vasculopathy. However, little is known about the intracellular pathways that mediate these biologic responses of VSMCs. Extracellular signal‐regulated kinase (ERK) pathway plays a major role in cellular responses and vascular diseases. In this study, we observed that the inhibition of ERK2 activity by recombinant adenovirus encoding antisense ERK2 (Adanti‐ERK2) significantly suppressed the proliferation, converting of cell cycle from G1 phase to S phase and directed migration, and partially abrogated transforming growth factor‐β1 (TGF‐β1) expression in VSMCs stimulated with PDGF‐BB. Ex vivo gene transfer of Adanti‐ERK2 into rat aortic allograft attenuated chronic transplant vasculopathy by the inhibition of VSMC proliferation and migration. In conclusion, ERK2 is involved in PDGF‐BB‐induced VSMCs proliferation, migration and TGF‐β1 expression and may be a potential therapeutic target for transplant vasculopathy.

Immunoregulatory effects of sirolimus vs. tacrolimus treatment in kidney allograft recipients.

The difference in immunoregulatory effects between sirolimus and tacrolimus on kidney transplantation remains unclear. In this study, a total of 18 living-donor-related kidney transplant recipients received sirolimus (n=8) or tacrolimus (n=10) treatment. Kidney function, acute rejection, peripheral blood CD4(+)CD25(+)FOXP3(+) regulatory T cells (Tregs), CD19(+)CD5(+)CD1d(+) regulatory B cells (Bregs), and panel reactivity antibody were analyzed after one and three years. Th1/2 cell polarization was also determined at one year. The proportion of Tregs in the recipients receiving tacrolimus significantly decreased to 3.69% and 2.49% at one and three years, respectively, compared to 6.59% in controls, whereas the proportion in the recipients receiving sirolimus remained at 6.67% and 5.66%, respectively. However, no differences in kidney function, acute rejection, proportion of Bregs, panel reactivity antibody, or the frequencies of Th1/2 cells were identified. In conclusion, unlike tacrolimus, sirolimus maintains the proportion of Tregs in kidney transplant recipients.

Administration of anti-interleukin-6 monoclonal antibody prolongs cardiac allograft survival

To investigate the effects of anti‐IL‐6 monoclonal antibody (anti‐IL‐6 mAb) on acute allograft rejection and the potential mechanisms in a mouse heart transplantation model. Heterotopical heart graft model was performed. The anti‐IL‐6 mAb was administered to recipient mice after cardiac grafting. Results were compared with administration of anti‐IL‐17 mAb or anti‐IL‐6 mAb + anti‐IL‐17 mAb (the ‘double’ treatment). The cardiac allograft survival was monitored by daily palpation in combination with histological evaluation. Quantitative polymerase chain reaction assay, mixed lymphocyte reaction, and flow cytometric analysis were employed to determine the mRNA expression of pro‐inflammatory cytokines, allogeneic T‐cell proliferation, and the proportion of CD4+ CD25+ Foxp3+ regulatory T cells in graft‐infiltrating lymphocytes and splenocytes of recipients, respectively. The results showed that the cardiac allograft survival in anti‐IL‐6 mAb‐treated mice was prolonged significantly when compared with that of the untreated or anti‐IL‐17 mAb‐treated mice. Meanwhile, the ‘double‐treated’ did not prolong graft survival significantly when compared with those treated with anti‐IL‐6 mAb. The increase of graft survival induced by anti‐IL‐6 mAb was associated with reduced transcript levels for IFN‐γ and IL‐17, accompanied by a dramatic reduction of T‐cell proliferation capacity to alloantigen stimuli and a higher proportion of Treg cells. Thus, anti‐IL‐6 mAb may be protective against acute rejection after cardiac transplantation through suppressing the activation of effector T cells and promoting the induction of Treg cells.

Adenovirus-mediated anti-sense ERK2 gene therapy inhibits tubular epithelial-mesenchymal transition and ameliorates renal allograft fibrosis.

PURPOSE Epithelial-mesenchymal transition (EMT) plays an important role in progress of renal allograft fibrosis. The adenovirus-mediated anti-sense extracellular signal-regulated kinase 2 (Adanti-ERK2) gene therapy was used to block ERK signaling pathway, and its effect on EMT and renal allograft fibrosis both in vivo and in vitro was explored. METHODS We first generated an in vitro EMT model by connective tissue growth factor (CTGF) stimulation in a HK-2 cell culture system, and then applied Adanti-ERK2 gene therapy on it. The transition of epithelial marker (E-cadherin) to mesenchymal markers (α-SMA, Vimentin) and the cell mobility function alteration were monitored for the observation of EMT progress. In vivo, a rat renal transplant model with Fisher-Lewis combination was employed and the Adanti-ERK2 gene therapy was given. The tubular EMT changes and pathology of allograft fibrosis were examined. RESULTS In vitro, Adanti-ERK2 gene therapy inhibited CTGF-induced tubular EMT and attenuated the cell motility function induced by CTGF. In vivo, Adanti-ERK2 gene therapy attenuated tubular EMT, modulated the infiltration of macrophages and CD8(+), CD4(+)T lymphocytes, and ameliorated fibrosis effectively in the renal allografts 24weeks after transplantation. CONCLUSIONS Adanti-ERK2 gene therapy inhibits tubular EMT and attenuates renal allograft fibrosis. It is possible to develop promising molecular drug(s) in the future based on ERK signaling pathway.

Protective effects of epigallocatechin-3-gallate on intestinal ischemia reperfusion injury through enhanced activation of PI3K/Akt pathway in rats

SummaryInflammation plays a critical role in intestinal ischemia reperfusion injury (IRI). Epigallocatechin-3-gallate (EGCG) has been demonstrated to possess anti-inflammatory effect. This study examined the effect of EGCG on intestinal IRI and explored the possible mechanisms. Male Wistar rats were randomly divided into three groups: sham-operated group (Sham), IRI control group (IRI) and IRI-EGCG group (EGCG). Rats in IRI-EGCG group were administered dissolved EGCG in drinking water (0.4 mg/mL) for 14 days prior to IRI induction. A rat model of intestinal IRI was established by ligating the superior mesenteric artery (SMA) for 30 min, followed by reperfusion for 1 h. Intestinal histology, pro-inflammatory cytokines and mediators were examined and the effect of EGCG on PI3K/Akt signalling was assessed. EGCG significantly alleviated the pathological changes of the intestine and suppressed the IRI-induced up-regulation of TNF-α, IL-1 and IL-6 mRNA and protein expression in the serum and intestine. The mechanism might be that EGCG enhanced the activation of PI3K/Akt signalling pathway. In conclusion, the administration of EGCG can significantly mitigate the acute intestinal IRI in rats by enhancing the activation of PI3K/Akt signalling pathway to suppress inflammatory response and might be a promising alternative for the prevention or treatment of intestinal IRI in the clinical practice.Inflammation plays a critical role in intestinal ischemia reperfusion injury (IRI). Epigallocatechin-3-gallate (EGCG) has been demonstrated to possess anti-inflammatory effect. This study examined the effect of EGCG on intestinal IRI and explored the possible mechanisms. Male Wistar rats were randomly divided into three groups: sham-operated group (Sham), IRI control group (IRI) and IRI-EGCG group (EGCG). Rats in IRI-EGCG group were administered dissolved EGCG in drinking water (0.4 mg/mL) for 14 days prior to IRI induction. A rat model of intestinal IRI was established by ligating the superior mesenteric artery (SMA) for 30 min, followed by reperfusion for 1 h. Intestinal histology, pro-inflammatory cytokines and mediators were examined and the effect of EGCG on PI3K/Akt signalling was assessed. EGCG significantly alleviated the pathological changes of the intestine and suppressed the IRI-induced up-regulation of TNF-α, IL-1 and IL-6 mRNA and protein expression in the serum and intestine. The mechanism might be that EGCG enhanced the activation of PI3K/Akt signalling pathway. In conclusion, the administration of EGCG can significantly mitigate the acute intestinal IRI in rats by enhancing the activation of PI3K/Akt signalling pathway to suppress inflammatory response and might be a promising alternative for the prevention or treatment of intestinal IRI in the clinical practice.

Impact of early biliary complications in liver transplantation in the presence or absence of a T-tube : a Chinese transplant centre experience

Background: Biliary complications continue to be an important determinant of the recipient’s survival rate after orthotopic liver transplantation (OLT). The objective of this study was to evaluate the incidence of early biliary complications in OLT in the presence or absence of a T-tube. Methods: This retrospective study, based on inpatient data, focused on the relationship between T-tube placement and early biliary complications of 84 patients after OLT, from November 2002 to June 2005. Patients were divided into two groups based on whether or not a T-tube was used following bile duct reconstruction: T-tube group (group I, n = 33); non-T-tube group (group II, n = 51). Results: 45.2% of OLT recipients had a malignant neoplasm. There were no significant differences in the demographic characteristics or operation data between the two groups. Overall, early biliary tract complications developed in 19.0% (16/84) of patients. The rate of early biliary complications was 30.3% (10/33) and 11.8% (6/51) in groups I II, respectively (p = 0.035). Biliary complications which were directly caused by T-tube placement occurred in 12.1% (4/33) of patients in group I. Overall, the percentage of malignant neoplasms, chronic viral cirrhosis, fulminant liver failure and other primary disease recipients with early biliary complications were 6.2%, 37.5%, 43.8% and 12.5%, respectively. Conclusion: This study suggests that the use of a T-tube in Chinese patients undergoing OLT causes a higher incidence of early biliary complications. Most of the early biliary complications occurred in chronic viral cirrhosis and fulminant liver failure recipients.

Patterns of Early Rejection in Renal Retransplantation: A Single-Center Experience

It has been reported that kidney retransplant patients had high rates of early acute rejection due to previous sensitization. In addition to the acute antibody-mediated rejection (ABMR) that has received widespread attention, the early acute T-cell-mediated rejection (TCMR) may be another important issue in renal retransplantation. In the current single-center retrospective study, we included 33 retransplant patients and 90 first transplant patients with similar protocols of induction and maintenance therapy. Analysis focused particularly on the incidence and patterns of early acute rejection episodes, as well as one-year graft and patient survival. Excellent short-term clinical outcomes were obtained in both groups, with one-year graft and patient survival rates of 93.9%/100% in the retransplant group and 92.2%/95.6% in the first transplant group. Impressively, with our strict immunological selection and desensitization criteria, the retransplant patients had a very low incidence of early acute ABMR (6.1%), which was similar to that in the first transplant patients (4.4%). However, a much higher rate of early acute TCMR was observed in the retransplant group than in the first transplant group (30.3% versus 5.6%, P < 0.001). Acute TCMR that develops early after retransplantation should be monitored in order to obtain better transplant outcomes.

Classic orthotopic liver transplantation without venovenous bypass: a report of 45 cases

THE CLASSIC orthotopic liver transplantation with venovenous bypass has both advantages and disadvantages. Advantages include maintaining the balance of the internal environment, relieving gastrointestinal congestion, decreasing blood loss, and protecting of bypass renal function during the anhepatic period. Disadvantages include the amount of time consumed, expensive cost, blood cell destruction, and complications to the blood vessels used for bypass. This article reviews the experience in 45 cases of classic orthotopic liver transplantation without venovenous bypass.

Recombinant IL-33 prolongs leflunomide-mediated graft survival by reducing IFN-γ and expanding CD4(+)Foxp3(+) T cells in concordant heart transplantation.

Interleukin (IL)-33 is a novel IL-1 family member, and its administration has been associated with promotion of T helper type-2 (Th2) cell activity and cytokines, particularly IL-4 and IL-5 in vivo. Recently, IL-33 was shown to increase CD4+Foxp3+ regulatory T cells (Tregs) and to suppress levels of the Th1-type cytokine IFN-γ in allogeneic heart transplantation in mice. Therefore, we hypothesized that IL-33 and leflunomide (Lef) could prolong graft survival in the concordant mouse-to-rat heart transplantation model. In this model, xenografts undergo acute humoral xenograft rejection (AHXR) typically on day 3 or cell-mediated rejection approximately on day 7 if AHXR is inhibited by Lef treatment. Recipients were treated with Lef (n=6), IL-33 (n=6), IL-33 combined with Lef (n=6), or left untreated (n=6) for survival studies. Heart grafts were monitored until they stopped beating. Mouse heterotopic grafts were performed, and recipients were sacrificed on days 2 and 7 for histological and flow cytometric analyses. The combination of IL-33 and Lef significantly prolonged the grafts from 17.3±2.3 to 2.8±0.4 days, compared to untreated controls. IL-33 administration with Lef, while facilitating Th2-associated cytokines (IL-4 on day 2 but not day 7), also decreased IFN-γ on day 2 and day 7, compared with Lef treatment only. Furthermore, IL-33 with Lef administration caused an expansion of suppressive CD4+Foxp3+ Tregs in rats. The IL-33 and Lef combination therapy resulted in significantly prolonged graft survival, associated with markedly decreased Th1 cells and increased IL-10 levels. In addition, the combination therapy significantly decreased the percentage of CD-45+ B cells on days 2 and 7, compared with monotherapy. These findings reveal a new immunoregulatory property of IL-33. Specifically, it facilitates regulatory cells, particularly functional CD4+Foxp3+ Tregs that underlie IL-33-mediated cardiac xenograft survival. Moreover, it can decrease Th1 cells and cytokine expression of Th1 T cells in xenograft recipients, for example IFN-γ.

Graft-versus-host-disease after kidney transplantation: A case report and literature review

Introduction: Acute graft-versus-host-disease (GVHD) in kidney recipients is extremely rare. Knowledge about its clinical manifestations, diagnosis, treatment, and prognosis is limited and needs to be increased. Clinical Findings: One male kidney transplant recipient developed diarrhea and suffered kidney function damage. Primarily diagnosed with acute rejection, he was given methylprednisolone (MP) bolus treatment. Meanwhile, intravenous immunoglobulin (IVIG) and decreased immunosuppressive agents were applied for the corresponding infection. During the treatment, skin rashes occurred over his whole body. Biopsies were then taken. The pathology of the kidney graft showed no rejection, while the skin pathology revealed typical GVHD. Furthermore, fluorescence in situ hybridization proved the presence of donor-derived cells in the skin lesions, and infiltrating cytotoxic T cells and NK cells were identified in the rash. Outcome: Based on the clinical presentations, pathological findings, and chimerism detection, GVHD after kidney transplantation was confirmed as the final diagnosis. The recipient responded well to treatment. His kidney function recovered, and the skin lesions were completely resolved. He has been followed for 1 year without any further episodes. Conclusion: GVHD after kidney transplantation has its own characteristics. In the presence of a highly immunocompromised state, diarrhea and rashes, a diagnosis of GVHD needs to be considered. Kidney function impairment may be involved. Pathological changes and detection of chimerism and immunocyte infiltration are required for diagnosis. MP bolus, IVIG, and decreased immunosuppression could be beneficial to the clinical outcome. Kidney recipients have a prognosis superior to recipients of organs bearing large numbers of lymphocytes.