Natural inhibitor of transforming growth factor-beta protects against scarring in experimental kidney disease.

The central pathological feature of human kidney disease that leads to kidney failure is the accumulation of extracellular matrix in glomeruli. Overexpression of transforming growth factor-beta (TGF-beta) underlies the accumulation of pathological matrix in experimental glomerulonephritis. Administration of an antibody raised against TGF-beta to glomerulonephritic rats suppresses glomerular matrix production and prevents matrix accumulation in the injured glomeruli. One of the matrix components induced by TGF-beta, the proteoglycan decorin, can bind TGF-beta and neutralize its biological activity, so decorin may be a natural regulator of TGF-beta (refs 3, 4). We tested whether decorin could antagonize the action of TGF-beta in vivo using the experimental glomerulonephritis model. We report here that administration of decorin inhibits the increased production of extracellular matrix and attenuates manifestations of disease, confirming our hypothesis. On the basis of our results, decorin may eventually prove to be clinically useful in diseases associated with overproduction of TGF-beta.     

高脂血症大鼠肾脏Angptl4变化及辛伐他汀的保护作用

为探讨高脂血症大鼠（Rattus norregicus）肾脏中Angptl4的变化及辛伐他汀的保护作用,将45只雄性SD大鼠随机平均分为3组：正常对照组（NG）给予普通饲料喂养;高脂饮食组（HG）给予高脂饲料喂养;辛伐他汀组（SG）在高脂饲料喂养的基础上给予辛伐他汀10mg·kg^-1·d^-1水溶液灌胃。分别于第4、6、lO周时各组随机选取5只大鼠,检测大鼠24h尿蛋白及血清总胆固醇（TC）和低密度脂蛋白胆固醇（LDL-C）水平,石蜡切片HE染色观察大鼠肾小球的损害,免疫组化及Western blot检测大鼠肾脏Angptl4蛋白分布及表达。结果显示,于第4周开始,HG组和sG组大鼠血清TC和LDL-C水平升高。实验第10周时,HG组和SG组大鼠24h尿蛋白定量升高;大鼠肾组织HE染色光镜下观察显示：肾小球呈轻微分叶状,系膜区增宽和基质增多不明显,但肾小球内有较明显的空泡变性,SG组大鼠的病变明显轻于HG组;免疫组化和免疫印迹检查发现,大鼠肾脏Angptl4明显增多,SG组的表达较HG组有减少。研究认为,高脂血症可引起肾脏肾小球明显病变,可能是肾小球内的足细胞分泌Angptl4的增多引起;而辛伐他汀则可能使高脂饮食时足细胞分泌Angptl4减少,从而减轻高脂血症时肾小球受到的损害。     

5 /6 肾切除小鼠中矿物质与骨代谢紊乱的特征

摘要: 目的通过制备5 /6 肾切除( 5 /6 Nx) 小鼠慢性肾脏病( CKD) 模型,观察小鼠成纤维生长因子23( FGF23) 及钙磷代谢指标,有助于研究矿物质与骨代谢紊乱的发病机制。方法28 只C57 雄性小鼠适应性饲养1 周后,切除模型组约5 /6 左肾,1周后切除右肾, 16 周后处死后收集血尿和肾脏组织标本,常规检测血尿FGF23、甲状旁腺素( PTH) 、活性维生素D、钙、磷等指标,观察肾脏病理。结果与假手术组和正常对照组相比,术后16 周5 /6 Nx 小鼠出现体质量减低,血清FGF23、PTH,血磷等异常升高,活性维生素D 水平显著降低,尿蛋白增加。肾脏病理发现系膜基质增生、胶原沉积及纤维化明显,和肾小球代偿性肥大。结论5 /6 Nx 小鼠可以出现明显的矿物质与骨代谢紊乱特征,是研究CKD 骨病合适的模型。     

原发性系膜增生性肾小球肾炎病变与临床表现关系的研究

将８０例肾穿刺活检确诊的原发性系膜增生性肾小球肾炎病变程度分为轻、中、重３级，结合临床表现、肾脏组织学改变及免疫病理，发现临床伴有高血压、反复水肿者病变均较严重；系膜节段性硬化和球囊粘连均见于重度病例；随着病变加重，肾小管萎缩和间质病变发生率增高；系膜区免疫沉积物以ＩｇＭ为主，重症病例ＩｇＭ沉积的发生率比轻、中症者高。     

Requirement of tumour necrosis factor for development of silica-induced pulmonary fibrosis

The deposition of silica particles in the lung of man or experimental animals leads to silicosis, a disease of progressive respiratory failure caused by a fibrotic reaction. It has long been suspected that the phagocytosis of silica by pulmonary macrophages induces the secretion of fibrogenic factors. Several potentially fibrogenic cytokines released by macrophages have been identified, including interleukin-1 (IL-1), tumour necrosis factor-alpha (TNF), platelet-derived growth factor, basic fibroblast growth factor and transforming growth factor-beta (TGF-beta). Here we show that TNF plays an important part in silica-induced pulmonary fibrosis in mice in that (1) a single instillation of silica leads to a marked increase in the level of lung TNF messenger RNA which lasts for greater than 70 days, while there are no obvious changes in the amounts of IL-1 alpha or TGF-beta mRNAs; and (2) silica-induced collagen deposition is almost completely prevented by anti-TNF antibody, but is significantly increased by continuous infusion of mouse recombinant TNF.     

肝再生过程中肾desmin和GFAP的表达以及MMPs的变化

采用免疫组织化学法和明胶酶谱电泳法研究大鼠肝部分切除(PH)后再生过程中肾结蛋白(desmin)和胶质纤维酸性蛋白(GFAP)的表达以及基质金属蛋白酶-2(MMP-2),-9(MMP-9)的活性变化.免疫组织化学结果显示,肝再生过程中肾小球系膜细胞、足细胞和间质细胞表达desmin和GFAP,而且二者的表达在PH后均经历了先减少后恢复的过程.明胶酶谱电泳结果显示,在对照组,检测到1条92 kD(pro MMP-9,MMP-9酶原形式)蛋白酶带,具有强的活性.在PH后8 d到14 d检测到了92 kD,86 kD(MMP-9),72 kD(pro MMP-2,MMP-2酶原形式)和66 kD(MMP-2)4条蛋白酶带.从第10 d到14 d,pro MMP-9和MMP-9活性逐渐增强,pro MMP-2和MMP-2活性逐渐降低.     

Cytoplasmic PML function in TGF-beta signalling

Transforming growth factor beta (TGF-beta) is a pluripotent cytokine that controls key tumour suppressive functions, but cancer cells are often unresponsive to it. The promyelocytic leukaemia (PML) tumour suppressor of acute promyelocytic leukaemia (APL) accumulates in the PML nuclear body, but cytoplasmic PML isoforms of unknown function have also been described. Here we show that cytoplasmic Pml is an essential modulator of TGF-beta signalling. Pml-null primary cells are resistant to TGF-beta-dependent growth arrest, induction of cellular senescence and apoptosis. These cells also have impaired phosphorylation and nuclear translocation of the TGF-beta signalling proteins Smad2 and Smad3, as well as impaired induction of TGF-beta target genes. Expression of cytoplasmic Pml is induced by TGF-beta. Furthermore, cytoplasmic PML physically interacts with Smad2/3 and SARA (Smad anchor for receptor activation) and is required for association of Smad2/3 with SARA and for the accumulation of SARA and TGF-beta receptor in the early endosome. The PML-RARalpha oncoprotein of APL can antagonize cytoplasmic PML function and APL cells have defects in TGF-beta signalling similar to those observed in Pml-null cells. Our findings identify cytoplasmic PML as a critical TGF-beta regulator, and further implicate deregulated TGF-beta signalling in cancer pathogenesis.     

近视巩膜生物力学研究进展

 近视是一种最为常见的具有致盲可能性的眼部疾患，其发病机制目前尚不完全明晰。巩膜可直接决定眼轴的长度，是近视形成的最终效应器。本文以巩膜为切入点，综述近视发生时巩膜组织生物力学性质的变化、相应巩膜组织成分的改变与原因，以及目前临床上针对性的近视治疗方案，展望了该研究领域的发展方向和趋势。     

An IgG autoantibody which inactivates C1-inhibitor

Antibodies are considered to play a specific pathogenic role in certain disease states such as myasthenia gravis, Graves' disease and autoimmune haemolytic anaemia. Autoantibodies which interfere with the function of enzyme cascade systems have also been described in diseases such as acquired haemophilia (anti-factor VIII antibodies) and glomerulonephritis (C3 nephritic factor). The identification of these autoantibodies is crucial to an understanding of the aetiology of such diseases and is also of importance in revealing the inter-relationships of the immune system with other biological pathways. This is the first report of an immunoglobulin G (IgG) autoantibody reactive with C1-inhibitor (C1-Inh), a pivotal inhibitor of the inflammatory response which is known to inactivate proteins of the complement, kinin, fibrinolytic and 'contact phase' systems. This autoantibody was isolated from a patient with a novel variant of acquired angioedema and C1-Inh dysfunction. This finding highlights the involvement of the immune system in the pathogenesis of disorders characterized by the presence of dysfunctional inflammatory response proteins.     

Protease nexin-II, a potent antichymotrypsin, shows identity to amyloid beta-protein precursor

Protease nexin-II (PN-II) is a protease inhibitor that forms SDS-resistant inhibitory complexes with the epidermal growth factor (EGF)-binding protein, the gamma-subunit of nerve growth factor, and trypsin. The properties of PN-II indicate that it has a role in the regulation of certain proteases in the extracellular environment. Here we describe more of the amino-acid sequence of PN-II and its identity to the deduced sequence of the amyloid beta-protein precursor (APP). Amyloid beta-protein is present in neuritic plaques and cerebrovascular deposits in individuals with Alzheimer's disease and Down's syndrome. A monoclonal antibody against PN-II (designated mAbP2-1) recognized PN-II in immunoblots of serum-free culture medium from human glioblastoma cells and neuroblastoma cells, as well as in homogenates of normal and Alzheimer's disease brains. In addition, mAbP2-1 stained neuritic plaques in Alzheimer's disease brain. PN-II was a potent inhibitor of chymotrypsin with an inhibition constant Ki of 6 x 10(-10)M. Together, these data demonstrate that PN-II and APP are probably the same protein. The regulation of extracellular proteolysis by PN-II and the deposition of at least parts of the molecule in senile plaques is consistent with previous reports that implicate altered proteolysis in the pathogenesis of Alzheimer's disease.     

Two forms of transforming growth factor-beta distinguished by multipotential haematopoietic progenitor cells

Type-beta transforming growth factors (TGF-beta s) are polypeptides that act hormonally to control proliferation and differentiation of many cell types. Two distinct homodimeric TGF-beta polypeptides, TGF-beta 1 and TGF-beta 2 have been identified which show approximately 70% amino-acid sequence similarity. Despite their structural differences, TGF-beta 1 and TGF-beta 2 are equally potent at inhibiting epithelial cell proliferation and adipogenic differentiation. The recent immunohistochemical localization of high levels of TGF-beta in the bone marrow and haematopoietic progenitors of the fetal liver has raised the possibility that TGF-beta s might be involved in the regulation of haematopoiesis. Here we show that TGF-beta 1, but not TGF-beta 2, is a potent inhibitor of haematopoietic progenitor cell proliferation. TGF-beta 1 inhibited colony formation by murine factor-dependent haematopoietic progenitor cells in response to interleukin-3 (IL-3) or granulocyte-macrophage colony stimulating factor (GM-CSF), as well as colony formation by marrow progenitor cells responding to CSF-1 (M-CSF). The progenitor cell lines examined were approximately 100-fold more sensitive to TGF-beta 1 than TGF-beta 2, and displayed type-I TGF-beta receptors with affinity approximately 20-fold higher for TGF-beta 1 than TGF-beta 2. These results identify TGF-beta 1 as a novel regulator of haematopoiesis that acts through type-I TGF-beta receptors to modulate proliferation of progenitor cells in response to haematopoietic growth factors.     

Reciprocal developmental pathways for the generation of pathogenic effector TH17 and regulatory T cells

On activation, T cells undergo distinct developmental pathways, attaining specialized properties and effector functions. T-helper (T(H)) cells are traditionally thought to differentiate into T(H)1 and T(H)2 cell subsets. T(H)1 cells are necessary to clear intracellular pathogens and T(H)2 cells are important for clearing extracellular organisms. Recently, a subset of interleukin (IL)-17-producing T (T(H)17) cells distinct from T(H)1 or T(H)2 cells has been described and shown to have a crucial role in the induction of autoimmune tissue injury. In contrast, CD4+CD25+Foxp3+ regulatory T (T(reg)) cells inhibit autoimmunity and protect against tissue injury. Transforming growth factor-beta (TGF-beta) is a critical differentiation factor for the generation of T(reg) cells. Here we show, using mice with a reporter introduced into the endogenous Foxp3 locus, that IL-6, an acute phase protein induced during inflammation, completely inhibits the generation of Foxp3+ T(reg) cells induced by TGF-beta. We also demonstrate that IL-23 is not the differentiation factor for the generation of T(H)17 cells. Instead, IL-6 and TGF-beta together induce the differentiation of pathogenic T(H)17 cells from naive T cells. Our data demonstrate a dichotomy in the generation of pathogenic (T(H)17) T cells that induce autoimmunity and regulatory (Foxp3+) T cells that inhibit autoimmune tissue injury.     

An in-depth analysis of proteomics expression profiling in rat glomeruli utilizing LC-MS

Glomeruli are an essential functional element of renal filtration. The majority of renal diseases caused by glomerular sclerosis or fibrosis may result in renal dysfunction. A fomulate protein profile, a comprehensive analysis of glomeruli of normal rats was conducted in this study via protein spectrum. Functional annotation and classification of these proteins were performed and it was found that 26 had the same glomerule (endothelial cells, podocytes and mesangial cells) markers with proteins.     

Connective tissue growth factor induces transformation of renal fibroblasts into myofibroblasts

Connective tissue growth factor (CTGF) is thought to be a specific mediator of TGF-β profibrogenic effect, but the role of CTGF in the transformation of renal fibroblasts to myofibroblasts, which are the most important host cells in the renal chronic fibrosis, is still unknown. Aimed at observing the biological effect of CTGF, we set up a cell line overexpressing CTGF, and analyzed the amount of myofibroblast and the level of extracellular matrix Collagen Ⅲ mRNA in cultured cells. Our results show that CTGF can directly induce myofibroblasts formation, and increase the level of Collagen Ⅲ mRNA. This suggests that CTGF may be a novel pharmacotherapeutical target protein for the interference with renal fibrosis, thus providing useful theoretic possibility for clinical prevention of chronic progression of kidney disease.     

700例慢性肾功能衰竭病因调查分析

通过分析慢性肾功能衰竭（chronic renal failure,CRF）病因的发病状况,证明早期及时治疗原发病对于降低或延缓CRF的重要性。对象和方法：分别从华西附一医院、华西附二医院、四川省医院、成都长城肾脏病医院选取确诊为CRF的700例患者进行面对面的问卷调查,得出相应的结果。调查结果显示：慢性肾功能衰竭在已明确的病因中仍以原发性肾小球肾炎为主要病因,其次为糖尿病肾病、高血压肾病、痛风性肾病。     

T-cell-expressed proprotein convertase furin is essential for maintenance of peripheral immune tolerance

Furin is one of seven proprotein convertase family members that promote proteolytic maturation of proproteins. It is induced in activated T cells and is reported to process a variety of substrates including the anti-inflammatory cytokine transforming growth factor (TGF)-beta1 (refs 2-4), but the non-redundant functions of furin versus other proprotein convertases in T cells are unclear. Here we show that conditional deletion of furin in T cells allowed for normal T-cell development but impaired the function of regulatory and effector T cells, which produced less TGF-beta1. Furin-deficient T regulatory (Treg) cells were less protective in a T-cell transfer colitis model and failed to induce Foxp3 in normal T cells. Additionally, furin-deficient effector cells were inherently over-active and were resistant to suppressive activity of wild-type Treg cells. Thus, our results indicate that furin is indispensable in maintaining peripheral tolerance, which is due, at least in part, to its non-redundant, essential function in regulating TGF-beta1 production. Targeting furin has emerged as a strategy in malignant and infectious disease. Our results suggest that inhibiting furin might activate immune responses, but may result in a breakdown in peripheral tolerance.     

Activin-like factor from a Xenopus laevis cell line responsible for mesoderm induction

Induction of mesoderm during early amphibian embryogenesis can be mimicked in vitro by adding growth factors, including heparin-binding and type-beta transforming growth factors (TGF-beta), to isolated ectoderm explants from Xenopus laevis embryos. Although the mesoderm-inducing factor (MIF) from X. laevis XTC cells (XTC-MIF) has properties similar to TGF-beta, this factor is still unidentified. Recently, we obtained a number of homogeneous cell lines from the heterogeneous XTC population, which differ in their MIF production. Only one, XTC-GTX-11, produced MIF, although it was similar to the rest of the clones in its production of known growth factors, including TGF-beta activity. This observation, together with the identification of activin A as a potent MIF led us to study the parallel activities of MIF and activin. Here we report an analysis of activin-like activity from XTC cells and some of the XTC clones, including XTC-GTX-11. There is a clear consistent correlation between MIF activity and presence of activin activity, indicating that XTC-MIF is the Xenopus homologue of mammalian activin.