Agents in development for the treatment of diabetic nephropathy

Diabetic nephropathy is a leading cause of end-stage renal disease, and accounts for significant morbidity and mortality in patients with diabetes. Diabetic nephropathy seems to occur as a result of an interaction between metabolic and haemodynamic factors, which activate common pathways that lead to renal damage. In the past, the treatment of diabetic nephro-pathy has focused on the control of hyperglycaemia. Newer targets, some of which are linked to glucose-dependent pathways, appear to be a major focus of new treatments directed against the development and progression of renal damage as a result of diabetes. It is anticipated that additional thera-peutic approaches that inhibit both metabolic and haemodynamic pathways will include strategies that target growth factors, cytokines and intracellular second messengers. Such an approach is expected to lead to improved therapies for the treatment of diabetic nephropathy.     

三七总苷对酒精性肝损伤大鼠肝脏TGV-β1／Smads、CTGFmRNA表达的影响

目的 研究三七总苷对酒精性肝损伤大鼠肝脏TGF-β1/Smads和CTGF表达的影响。方法 大鼠灌服白酒-玉米油-吡唑混合液14周,建立酒精性肝损伤模型。成模大鼠随机分成模型组、三七总苷组（高、低剂量组）、水飞蓟素组,同时另设正常对照组,均治疗4周后,测定肝功能、大鼠肝组织TGF-β1、Smad3、Smad7、CTGFmRNA的表达量。结果 与模型组比较,三七总苷组能明显降低血清中谷丙转氨酶（ALT）、谷草转氨酶（AST）以及总胆红素（TB）水平,减少肝组织TGF-β1、Smad3、Smad7、CTGF mRNA的表达量;不同剂量组之间,差异有统计学意义（P〈0.05）;高剂量三七总苷组与水飞蓟素组之间,差异无统计学意义（P〉0.05）。结论 三七总苷与对酒精性肝损伤大鼠肝脏TGF-β1/Smads、CTGF表达有抑制作用。     

Comparison of TGF-β, PDGF,and CTGF in hepatic fibrosis models using DMN,CCl4, and TAA

Three chemotoxins including dimethylnitrosamine (DMN), carbon tetrachloride (CCl₄), and thioacetamide (TAA) are commonly used in hepatofibrotic models. We aimed to draw characteristics of histopathology and pro-fibrogenic cytokines including TGF-β, PDGF and CTGF among three models. Rats were divided into six groups and intra-peritoneally injected with DMN (10?mg/kg, for three weeks, three consecutive days weekly), CCl₄ (1.6?g/kg, for 10 weeks, twice weekly), TAA (200?mg/kg, for 12 weeks, twice weekly) or their corresponded treatment for each control group. The liver weights were decreased in DMN model, but not other models. Ascites were occurred as 3-, 2-, and 7-rats in DMN, CCl₄, and TAA model, respectively. The lipid peroxidation was highest in CCl₄ model, serum levels of liver enzymes were increased as similar severity. The hepatofibrotic alterations were remarkable in DMN and TAA model, but not CCl₄ as evidenced by the Masson trichrome staining and hydroxyproline. The immunohistochemistry for α-SAM showed that the DMN model was most severely enhanced than other models. On the other hand, hepatic tissue levels of pro-fibrogenic cytokines including TGF-β, PDGF, and CTGF were generally increased in three models, but totally different among models or measurement resources. Especially, serum levels of three cytokines were remarkably increased by CCl₄ injection and CTGF levels in both hepatic tissue and serum were highest in CCl₄ group. Our results firstly demonstrated comparative study for features of morphological finding and pro-fibrogenic cytokines in serum and hepatic protein levels among three models. Above results would be a helpful reference for hepatofibrotic studies.     

Renal targeting of kinase inhibitors

Activation of proximal tubular cells by fibrotic and inflammatory mediators is an important hallmark of chronic kidney disease. We have developed a novel strategy to intervene in renal fibrosis, by means of locally delivered kinase inhibitors. Such compounds will display enhanced activity within tubular cells and reduced unwanted systemic effects. In our approach kinase inhibitors are linked to the renal carrier lysozyme using a platinum-based linker that binds drugs via a coordinative linkage. Many kinase inhibitors contain aromatic nitrogen atoms able to bind to this linker without the need of prior derivatization. The resulting drug-lysozyme conjugates are rapidly filtered in the glomerulus into the tubular lumen and subsequently reabsorbed via the endocytic pathway for clearance of low-molecular weight proteins. An important property of the formed conjugates is their in vivo stability and the sustained drug release profile within target cells. This review summarizes the state-of-the-art of drug targeting to the kidney. Furthermore, we will highlight recent results obtained with kinase inhibitor-lysozyme conjugates targeted to different kinases, i.e. the transforming growth factor (TGF)-beta-receptor kinase, p38 MAPkinase and Rho-associated kinase. Both in vitro and in vivo results demonstrated their efficient tubular uptake and beneficial therapeutic effects, superior to treatment with free kinase inhibitors. These proof-of-concept studies clearly indicate the feasibility of drug targeting for improving the renal specificity of kinase inhibitors.     

参地补肾胶囊对肾小球硬化大鼠BMP-7、CTGF表达的影响

目的:探讨参地补肾胶囊对肾小球硬化大鼠BMP-7、CTGF表达的影响。方法:采用单侧肾脏切除同时尾静脉注射阿霉素的方法建立肾小球硬化大鼠模型,实验分为正常对照组、模型组、西药(洛汀新)对照组、中药(苏黄泄浊丸)组和参地补肾胶囊组,分组给药处理8周。检测各组大鼠24小时尿蛋白定量、血肌酐(SCr)、尿素氮(BUN)、血浆蛋白(ALB);光镜观察大鼠肾脏病理学变化;免疫组化法检测BMP-7、CTGF表达。结果:各治疗组大鼠24小时尿蛋白及血SCr、BUN、ALB较模型组明显改善(P0.05)。各给药组大鼠肾脏病理变化明显改善。各治疗组均能抑制CTGF的表达(P0.05),上调BMP-7表达(P0.05);参地补肾胶囊组作用明显优于两阳性对照组(P0.05)。结论:参地补肾胶囊对肾小球硬化大鼠肾功能具有保护作用,上调BMP-7表达、抑制CTGF表达可能是其部分作用机制。     

VEGF及CTGF的表达与脑胶质瘤分级的相关性研究

目的通过检测脑胶质瘤患者肿瘤组织中血管内皮生长因子和结缔组织生长因子的表达水平,探讨其和肿瘤级别的关系及作用机制。方法应用免疫组化SP法检测49例胶质瘤手术标本中的VEGF和CTGF的表达水平,统计分析表达水平和肿瘤级别之间的关系。结果VEGF和CTGF在胶质瘤高级别组（Ⅲ-Ⅳ级）中的表达均明显高于低级别组（Ⅰ-Ⅱ级）,说明随着肿瘤级别的升高VEGF和CTGF表达也增强。结论VEGF和CTGF在胶质瘤组织中高表达,而且表达水平和恶性程度有密切联系。VEGF和CTGF的检测可作为胶质瘤恶性程度判断的参考,为从基因水平上探讨胶质瘤的生物学行为、预后及治疗提供新的思路。     

结缔组织生长因子在非小细胞肺癌中的表达及相关性研究

目的：观察结缔组织生长因子（CTGF）在非小细胞肺癌（NSCLC）组织和正常肺组织中表达的差异性,并初步探讨CTGF表达与NSCLC恶性程度、侵袭和转移的关系。方法：采用免疫组织化学法（S-P法）检测50例NSCLC和10例正常肺组织中CTGF的表达情况,并分析CTGF与NSCLC患者临床病理特征之间的关系,以及CTGF在NSCLC组织中表达的相关性。结果：在50例NSCLC组织中有15例（30%）CTGF呈阳性表达,10例正常肺组织中有9例为阳性表达;统计结果显示,CTGF表达与NSCLC的临床分期（P=0.005）、淋巴结转移（P=0.04）有相关性。结论：CTGF在NSCLC组织中的表达较正常肺组织明显下调,与NSCLC的临床分期和淋巴结转移有相关性,提示CTG可能与NSCLC的侵润和转移有关。     

The development of cardiac fibrosis in low tissue factor mice is gender-dependent and is associated with differential regulation of urokinase plasminogen activator

Tissue factor (TF) initiates the protease coagulation cascade in response to tissue injury. Homozygous deficiency of murine TF results in embryonic lethality, which is rescued by low-level expression of human TF. These low-TF mice have been shown to develop cardiac fibrosis. We tested the hypothesis that the development of cardiac fibrosis in low-TF mice results from dysregulated protease expression and is affected by gender. Mice were divided into the age groups 2-5, 6-12, 13-18 and 19+ weeks. Fibrosis was assessed by trichrome staining. Protease expression was measured in male and female mice by RT-PCR for mRNA and zymography, ELISA or immunoblot for protein. Urokinase plasminogen activator (uPA) activity was determined by zymography and chromogenic substrate assay. A marked gender effect was noted for the development of fibrosis, with interstitial collagen deposition occurring from 9 weeks in male low-TF mice, but not until 19 weeks in low-TF females. This delayed onset in females was accompanied by delayed up-regulation of molecular markers of injury. Matrix metalloproteinase (MMP)-3 and tissue inhibitor of metalloproteinase (TIMP)-1 expression were up-regulated in the hearts of male low-TF mice from 6 to 12 weeks and in females from 19 weeks. MMP/TIMP dysregulation was not seen prior to cardiac fibrosis and did not appear to explain the gender differences. However, uPA expression and activity were down-regulated prior to cardiac fibrosis in low-TF females, but were up-regulated in age-matched males. This suggests that the down-regulation of uPA in female low-TF mice protects them from more severe cardiac fibrosis.     

Successful mitigation of delayed intestinal radiation injury using pravastatin is not associated with acute injury improvement or tumor protection

PURPOSE: To investigate whether pravastatin mitigates delayed radiation-induced enteropathy in rats, by focusing on the effects of pravastatin on acute cell death and fibrosis according to connective tissue growth factor (CTGF) expression and collagen inhibition. METHODS AND MATERIALS: Mitigation of delayed radiation-induced enteropathy was investigated in rats using pravastatin administered in drinking water (30 mg/kg/day) 3 days before and 14 days after irradiation. The ileum was irradiated locally after surgical exteriorization (X-rays, 19 Gy). Acute apoptosis, acute and late histologic alterations, and late CTGF and collagen deposition were monitored by semiquantitative immunohistochemistry and colorimetric staining (6 h, 3 days, 14 days, 15 weeks, and 26 weeks after irradiation). Pravastatin antitumor action was studied in HT-29, HeLa, and PC-3 cells by clonogenic cell survival assays and tumor growth delay experiments. RESULTS: Pravastatin improved delayed radiation enteropathy in rats, whereas its benefit in acute and subacute injury remained limited (6 h, 3 days, and 14 days after irradiation). Delayed structural improvement was associated with decreased CTGF and collagen deposition but seemed unrelated to acute damage. Indeed, the early apoptotic index increased, and severe subacute structural damage occurred. Pravastatin elicited a differential effect, protecting normal intestine but not tumors from radiation injury. CONCLUSION: Pravastatin provides effective protection against delayed radiation enteropathy without interfering with the primary antitumor action of radiotherapy, suggesting that clinical transfer is feasible.