Fibrosis Progression According to Epithelial‐Mesenchymal Transition Profile: A Randomized Trial of Everolimus Versus CsA

Markers of epithelial‐mesenchymal transition (EMT) may identify patients at high risk of graft fibrogenesis who could benefit from early calcineurin inhibitor (CNI) withdrawal. In a randomized, open‐label, 12‐month trial, de novo kidney transplant patients received cyclosporine, enteric‐coated mycophenolate sodium (EC‐MPS) and steroids to month 3. Patients were stratified as EMT+ or EMT? based on month 3 biopsy, then randomized to start everolimus with half‐dose EC‐MPS (720 mg/day) and cyclosporine withdrawal (CNI‐free) or continue cyclosporine with standard EC‐MPS (CNI). The primary endpoint was progression of graft fibrosis (interstitial fibrosis/tubular atrophy [IF/TA] grade increase ≥1 between months 3–12) in EMT+ patients. 194 patients were randomized (96 CNI‐free, 98 CNI); 153 (69 CNI‐free, 84 CNI) were included in histological analyses. Fibrosis progression occurred in 46.2% (12/26) CNI‐free EMT+ patients versus 51.6% (16/31) CNI EMT+ patients (p = 0.68). Biopsy‐proven acute rejection (BPAR, including subclinical events) occurred in 25.0% and 5.1% of CNI‐free and CNI patients, respectively (p < 0.001). In conclusion, early CNI withdrawal with everolimus initiation does not prevent interstitial fibrosis. Using this CNI‐free protocol, in which everolimus exposure was relatively low and administered with half‐dose EC‐MPS, CNI‐free patients were overwhelmingly under‐immunosuppressed and experienced an increased risk of BPAR.

     

MicroRNA‐494 Promotes Cyclosporine‐Induced Nephrotoxicity and Epithelial to Mesenchymal Transition by Inhibiting PTEN

A major complication associated with cyclosporine (CsA) treatment is nephrotoxicity. In this study, we examined whether microRNAs play a role in cyclosporine‐induced nephrotoxicity. Treatment of mice with CsA resulted in nephrotoxicity that was associated with an early increase in expression of microRNA mmu‐miR‐494 (miR‐494). Similarly, tubular epithelial cell epithelial‐mesenchymal transition (EMT) induced by CsA toxicity resulted in the upregulation of microRNA‐494 and a decrease in PTEN levels in vitro. miR‐494 directly targeted Pten and negatively regulated its expression. Preventing Pten targeting by miR‐494 was sufficient to prevent CsA induced EMT. Knockdown of miR‐494 prevented the downregulation of PTEN in tubular epithelial cells following CsA treatment and also prevented CsA induced EMT. Thus, miR‐494 plays a major role in promoting CsA induced nephrotoxicity through its ability to target Pten thereby contributing to EMT. We suggest that manipulating miR‐494 expression may represent a novel approach to preventing EMT associated with CsA induced nephrotoxicity.     

Mesenchymal stromal cells for tolerance induction in organ transplantation

The primary challenge in organ transplantation continues to be the need to suppress the host immune system long-term to ensure prolonged allograft survival. Long-term non-specific immunosuppression can, however, result in life-threatening complications. Thus, efforts have been pursued to explore novel strategies that would allow minimization of maintenance immunosuppression, eventually leading to transplant tolerance. In this scenario, bone marrow-derived mesenchymal stromal cells (MSC), given their unique immunomodulatory properties to skew the balance between regulatory and memory T cells, have emerged as potential candidates for cell-based therapy to promote immune tolerance. Here, we review our initial clinical experience with bone marrow-derived MSC in living-donor kidney transplant recipients and provide an overview of the available results of other clinical programs with MSC in kidney and liver transplantation, highlighting hurdles and success of this innovative cell-based therapy.     

Impact of sampling time deviations on the prediction of the area under the curve using regression limited sampling strategies

The regression limited sampling strategy approach (R‐LSS), which is based on a small number of blood samples drawn at selected time points, has been used as an alternative method for the estimation of the area under the concentration–time curve (AUC). However, deviations from planned sampling times may affect the performance of R‐LSS, influencing related therapeutic decisions and outcomes. The aim of this study was to investigate the impact of different sampling time deviation (STD) scenarios on the estimation of AUC by the R‐LSS using a simulation approach. Three types of scenarios were considered going from the simplest case of fixed deviations, to random deviations and then to a more realistic case where deviations of mixed nature can occur. In addition, the sensitivity of the R‐LSS to STD in each involved sampling point was evaluated. A significant impact of STD on the performance of R‐LSS was demonstrated. The tolerance of R‐LSS to STD was found to depend not only on the number of sampling points but more importantly on the duration of the sampling process. Sensitivity analysis showed that sampling points at which rapid concentration changes occur were relatively more critical for AUC prediction by R‐LSS. As a practical approach, nomograms were proposed, where the expected predictive performance of R‐LSS was provided as a function of STD information. The investigation of STD impact on the predictive performance of R‐LSS is a critical element and should be routinely performed to guide R‐LSS selection and use. Copyright © 2015 John Wiley & Sons, Ltd.     

From Drosophila to Humans: Reflections on the Roles of the Prolyl Isomerases and Chaperones,Cyclophilins, in Cell Function and Disease

Abstract: Despite remarkable advances in human genetics and other genetic model systems, the fruit fly, Drosophila melanogaster, remains a powerful experimental tool to probe with ease the inner workings of a myriad of biological and pathological processes, even when evolutionary forces impart apparent divergences to some of such processes. The understanding of such evolutionary differences provides mechanistic insights into genotype-phenotype correlations underpinning biological processes across metazoans. The pioneering work developed by the William Pak laboratory for the past four decades, and the work of others, epitomize the notion of how the Drosophila system breaks new fertile ground or complements research fields of high scientific and medical relevance. Among the three major genetic complementation groups produced by the Pak's laboratory and impairing distinct facets of photoreceptor neuronal function, the nina group (ninaA, …., ninaJ) selectively affects the biogenesis of G protein–coupled receptors (GPCRs), mediating the photoconversion and transduction of light stimuli. Among the nina genes identified, ninaA arguably assumes heightened significance for several reasons. First, it presents unique physiological selectivity toward the biogenesis of a subset of GPCRs, a standalone biological manifestation yet to be discerned for most mammalian homologues of NinaA. Second, NinaA belongs to a family of proteins, immunophilins, which are the primary targets for immunosuppressive drugs at the therapeutic forefront of a multitude of medical conditions. Third, NinaA closest homologue, cyclophilin B (CyPB/PPIB), is an immunophilin whose loss-of-function was found recently to cause osteogenesis imperfecta in the human. This report highlights advances made by studies on some members of immunophilins, the cyclophilins. Finally, it reexamines critically data and dogmas derived from past and recent genetic, structural, biological, and pathological studies on NinaA and few other cyclophilins that support some of such paradigms to be less than definite and advance our understanding of the roles of cyclophilins in cell function, disease, and therapeutic interventions.     

Immunosenescence increases the rate of acceptance of kidney allotransplants in elderly recipients through exhaustion of CD4 T-cells

Compromised immunity is the hallmark of ageing. Paradoxically, it may be “an ally” in facilitating acceptance of allogeneic grafts in the elderly. In this retrospective study we looked for biomarkers of immunosenescence that distinguish elderly recipients less prone to reject kidney allografts.Recruited kidney recipients aged ≥60 or <60 were designated ‘elderly’ and ‘young’, respectively. Both age-groups were divided according to the history of acute rejection. The phenotype, length of telomeres, expression of FoxP3 and proliferative responses were assessed in CD4⁺ and CD8⁺ T-cell subsets. In addition, IL6, IL10 and TGFβ were measured on the level of mRNA and serum protein.Acute-rejection-free history in elderly transplant recipients was associated with short telomeres, a decreased proportion of CD28⁺ T-cells associated with CMV-seropositivity and low proliferation of CD4⁺ T-cells. In contrast, elderly recipients who experienced acute rejection kept preserved telomere length, had a higher number of functional CD4⁺CD28⁺ cells and exhibited vigorous proliferation in vitro. These differences were not found in the young group.The major conclusion of this study is that the impaired condition of CD4⁺ T-cells, so-called immunosenescence, renders transplant recipients less responsive to an allogeneic kidney graft, an effect that was limited to transplant recipients of >60 years of age.     

Monoclonal gammopathy (IgA:λ) after autologous T-cell-depleted bone marrow transplantation in a patient with non-Hodgkin's lymphoma

Summary We report a case study of a patient suffering from T-lymphoblastic lymphoma, for whom autologous T-cell-depleted bone marrow transplantation was carried out. Low-dose cyclosporin A (CsA) was administered just after autologous bone marrow transplantation (ABMT) for induction of autologous graft-versus-host disease. Three months later, the lymphoma relapsed with marked monoclonal gammopathy of the immunoglobulin A type, which had not been seen before ABMT. It is suggested that the regrowth of the lymphoma cells was related to the maturation of B cells or the secretion of immunoglobulins from plasma cells, associated with some cytokines produced under the condition of an abnormal immunological circumstance after ABMT plus CsA.     

ConA诱导肝细胞损伤机理及CsA对其损伤的影响

目的　探讨NO、脂质过氧化反应及蛋白巯基状态改变在ConA诱导肝组织细胞损伤过程中的作用以及CsA对其损伤的影响。方法 :尾静脉注射ConA( 2 0mg·kg-1)于雄性BALB/c小鼠作为试验组 ;提前半小时予以CsA( 2 5mg·kg-1)后再按试验组处理作为CsA组。观察血清中ALT、AST、NO-2 及肝组织MDA、TSH、PSH含量在 3h、6h、9h和 12h的动态变化。结果　试验组血清中ALT、AST进行性升高 ,在 12h时与对照组、CsA组比较均P <0 .0 1。试验组动物体内有大量的NO合成 ,血清中NO-2 随时间呈明显上升趋势 ,在 12h时与对照组、CsA组比较均P <0 .0 1。试验组动物肝组织MDA含量逐步升高 ,在 12h与对照组、CsA组比较P <0 .0 1。试验组动物肝组织TSH含量不断下降在 12h与对照组、CsA组比较P <0 .0 5 ;PSH含量亦不断下降在 12h与对照组、CsA组比较P <0 .0 1。对照组和CsA组血清中ALT、AST及NO-2 前后变化不大 ,肝组织MDA、TSH、PSH含量变化亦不明显。结论　在ConA所致肝损伤中 ,动物体内NO生物合成机制被激活 ,是肝细胞损伤的重要介质之一。同时脂质过氧化的发生以及蛋白巯基持续消耗致肝组织细胞的抗氧化能力和解毒能力下降也均是ConA性肝损伤机制之一。免疫抑制剂CsA预处理能阻断ConA性肝损伤的发生 ,免疫介导机制亦可能是其损伤     

苦参碱联合环孢素A减轻小鼠急性移植物抗宿主病

背景：苦参碱具有降低白细胞介素2浓度的作用,作为化疗辅助用药已用于临床。　 目的：探讨苦参碱联合环孢素A对小鼠异基因骨髓移植后急性移植物抗宿主病发生发展的影响,及苦参碱可能的作用机制。 方法：C57BL/6小鼠作为供鼠,BABL/C小鼠为受鼠,建立小鼠同种异基因骨髓移植模型。BALB/C受鼠随机分为7组：空白对照组、单纯照射组、骨髓移植组及足量环孢素A、半量环孢素A、足量苦参碱组、足量苦参碱联合半量环孢素A组。 结果与结论：足量苦参碱联合半量环孢素A组小鼠生存时间明显长于其他组。进行骨髓移植的小鼠均出现不同程度病理改变,越早程度越重。移植后7 d,与骨髓移植组比较,其他移植组小鼠血清γ-干扰素质量浓度下降,白细胞介素4质量浓度差异无显著性意义。提示,苦参碱能够减轻小鼠异基因骨髓移植后致死性急性移植物抗宿主病的发生,生存时间延长。苦参碱与环孢素A作用相似,二者联用,有协同作用。     

环孢霉素A对缺血再灌注心肌的保护作用与CD4+T细胞的关系

目的 观察环孢霉素A对缺血再灌注心肌的影响,并探讨其与CD4+T细胞之间的关系.方法 将32只SD大鼠随机分为4组(n=8): 假手术组(Sham)、缺血再灌注(I/R)模型组、环孢霉素(CsA)组、CsA+5-羟基葵酸盐(5-HD)组.CsA、CsA+5-HD组给予CsA 15 mg/kg及1 mL生理盐水腹腔注射,...