Nianqiao Gong

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.

Partial liver transplantation

Partial liver transplantation, including reducedsize liver transplantation, split liver transplantation, and living donor liver transplantation, has been developed with several innovative techniques because of donor shortage. Reduced-size liver transplantation is based on Couinaud’s anatomical classification, benefiting children and small adult recipients but failing to relieve the overall donor shortage. Split liver transplantation provides chances to two or even more recipients when only one liver graft is available. The splitting technique must follow stricter anatomical and physiological criteria either ex situ or in situ to ensure long-term quality. The first and most important issue involving living donor liver transplantation is donor safety. Before surgery, a series of donor evaluations—including anatomical, liver volume, and liver function evaluations—is indispensable, followed by ethnic agreement. At different recipient conditions, auxiliary liver transplantation and auxiliary partial orthotopic liver transplantation, which employ piggyback techniques, are good alternatives. Partial liver transplantation enriches the practice and knowledge of the transplant society.

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.

MG53 permeates through blood-brain barrier to protect ischemic brain injury

Ischemic injury to neurons represents the underlying cause of stroke to the brain. Our previous studies identified MG53 as an essential component of the cell membrane repair machinery. Here we show that the recombinant human (rh)MG53 protein facilitates repair of ischemia-reperfusion (IR) injury to the brain. MG53 rapidly moves to acute injury sites on neuronal cells to form a membrane repair patch. IR-induced brain injury increases permeability of the blood-brain-barrier, providing access of MG53 from blood circulation to target the injured brain tissues. Exogenous rhMG53 protein can protect cultured neurons against hypoxia/reoxygenation-induced damages. Transgenic mice with increased levels of MG53 in the bloodstream are resistant to IR-induced brain injury. Intravenous administration of rhMG53, either prior to or after ischemia, can effectively alleviate brain injuries in rats. rhMG53-mediated neuroprotection involves suppression of apoptotic neuronal cell death, as well as activation of the pro-survival RISK signaling pathway. Our data indicate a physiological function for MG53 in the brain and suggest that targeting membrane repair or RISK signaling may be an effective means to treat ischemic brain injury.

Epstein-Barr virus negative primary hepatic leiomyoma: Case report and literature review

Primary hepatic leiomyoma is a neoplasm of mesenchymal origin and occurs only rarely. Secondary to benign smooth muscle proliferation, it is usually found in adult women and is associated with Epstein-Barr virus (EBV) infection. Here, we report the 29(th) case of primary hepatic leiomyoma with its unique features related to diagnosis, treatment and developmental biology. A 48-year-old man, with an immunocompromised status, complained of pain in the upper quadrant of the abdomen. Serological analysis indicated no presence of hepatitis virus, no human immunodeficiency virus, and no EBV infection. The levels of α-fetoprotein and carcinoembryonic antigen were normal. A mass was detected in segment III of the hepatic lobe by ultrasonography and an abdominal computed tomography scan. Endoscopy had negative findings. Exploratory laparotomy found no existing extrahepatic tumor and left lateral lobectomy was performed. Pathological examination showed the mass to be a typical leiomyoma. The cells were positive for α-smooth muscle actin and desmin, and negative for the makers of gastrointestinal stromal tumor (GIST), including CD117, CD34 and DOG1 (discovered on GIST1). In situ hybridization revealed negative status for EBV-encoded small RNA. After left lateral lobectomy, the patient was not given chemotherapy or radiotherapy. During a 2-year follow-up, no sign of local recurrence or distant metastasis was observed. In conclusion, we report a rare case of primary hepatic leiomyoma in a male patient without EBV infection. Hepatic resection was curative. This case presents data to expand our knowledge concerning the complex and heterogeneous nature of primary liver leiomyoma, indicating that EBV infection is important but neither necessary nor sufficient for the development of primary liver leiomyoma.

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.

Chronic Allograft Nephropathy: The Mechanisms and Strategies

Chronic allograft nephropathy (CAN) is the main cause of long-term renal allograft loss. It is an active but slowly progressive injury mainly caused by alloreactivity to the graft, and further deteriorated by non-immunologic nonspecific factors. After an overview of the pathologic characteristics of CAN based on the Banff Working Classification, the underlying mechanisms and therapies are explored in this review, with an emphasis on novel theories and new findings. With regard to the mechanisms, indirect antigen presentation, ICOS-B7h costimulatory pathways, the roles of immune cells, humoral immunity, epithelial–mesenchymal transition and fibrogenesis are paid more attention than non-immunologic factors including calcineurin inhibitor (CNI) nephrotoxicity, ischemia/reperfusion, senescence and other various factors. With regard to therapeutic strategy, we line up the clinical and experimental proceedings based on the mechanisms. Sufficient immunosuppression, CNI sparing, rapamycin conversion, and administration of mycophenolate mofetil have been applied clinically and are discussed. New experimental therapies on deletion of humoral factors, blockade of costimulation pathway, intervention of fibrogenesis, blockade of signal transduction pathway, protection of endothelium and tissues, and induction of accommodation are introduced together with other nonspecific treatments. [Hong Kong J Nephrol 2007;9(2):58–69]

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.

The Soluble Tachyzoite Antigen of Toxoplasma gondii Has a Protective Effect on Mouse Allografts

BACKGROUND Infection with some types of parasites can significantly prolong allograft survival in mice. It is unknown whether the soluble tachyzoite antigen (STAg) from Toxoplasma gondii has the same effect and by what mechanism it acts. METHODS A mouse model of cardiac and skin allograft transplantation was established between BALB/c (H-2(d)) and C57BL/6(H-2(b)) mice. T gondii STAg was prepared, and 5 μg was administered subcutaneously to recipient mice 4 days before transplantation. The graft status was checked daily, and histologic and immunohistochemical assays were used to evaluate rejection. The serum cytokine levels from the recipient mice were analyzed by Luminex. RESULT The administration of 5 μg STAg 4 days before transplantation significantly prolonged the survival time of the heart and skin allografts to 85.17 ± 14.06 and 24.17 ± 2.32 days, respectively. Immunohistochemical staining showed that the CD4(+) and CD8(+) T lymphocytes were markedly reduced in the allografts at day 7 posttransplantation. Notably, interleukin (IL)-12, IL-2, and IL-17 levels were significantly reduced in the serum of mice treated with STAg compared with untreated mice 7 days after transplantation. In contrast, the levels of the antiinflammatory cytokine IL-10 were elevated. CONCLUSION A single administration of STAg before transplantation can significantly prolong the allograft survival time, which is accompanied by impaired lymphocyte infiltration and a reduced Th1 response.