Antisense oligonucleotides against collagen-binding stress protein HSP47 suppress peritoneal fibrosis in rats

BACKGROUND: Peritoneal fibrosis is a serious complication in patients on continuous ambulatory peritoneal dialysis (CAPD), but the molecular mechanism of this process remains unclear. Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, is essential for biosynthesis and secretion of collagen molecules, and is expressed in the tissue of human peritoneal fibrosis. In the present study, we examined the effect of HSP47 antisense oligonucleotides (ODNs) on the development of experimental peritoneal fibrosis induced by daily intraperitoneal injections of chlorhexidine gluconate (CG). METHODS: HSP47 antisense or sense ODNs were injected simultaneously with CG from day 14, after injections of CG alone. Peritoneal tissue was dissected out 28 days after CG injection. The expression patterns of HSP47, type I and type III collagen, alpha-smooth muscle actin (alpha-SMA), as a marker of myofibroblasts, ED-1 (as a marker of macrophages), and factor VIII were examined by immunohistochemistry. RESULTS: In rats treated with CG alone, the submesothelial collagenous compact zone was thickened, where the expression levels of HSP47, type I and type III collagen and alpha-SMA were increased. Marked macrophage infiltration was also noted and the number of vessels positively stained for factor VIII increased in the CG-treated group. Treatment with antisense ODNs, but not sense ODNs, abrogated CG-induced changes in the expression of HSP47, type I and III collagen, alpha-SMA, and the number of infiltrating macrophages and vessels. CONCLUSION: Our results indicate the involvement of HSP47 in the progression of peritoneal fibrosis and that inhibition of HSP47 expression might merit further clinical investigation for the treatment of peritoneal fibrosis in CAPD patients.     

Expression of heat shock proteins 47 and 70 in the peritoneum of patients on continuous ambulatory peritoneal dialysis

BACKGROUND: Peritoneal sclerosis, characterized by collagen accumulation, is a serious complication in continuous ambulatory peritoneal dialysis (CAPD) therapy. Heat shock protein 47 (HSP47) is a collagen-specific molecular chaperon and is closely associated with collagen synthesis. METHODS: We determined the expression of HSP47 and HSP70 (nonspecific for collagen synthesis) by immunohistochemistry in peritoneal tissues of patients on CAPD. The tissue for collagen III, alpha-smooth muscle actin (alpha-SMA), and CD68 (a marker for macrophages) were also stained. Thirty-two peritoneal samples were divided into three groups (group A1, 11 patients who had no ultrafiltration loss; group A2, 9 patients who had ultrafiltration loss; and group B, 12 specimens who had end-stage renal disease prior to induction of CAPD. RESULTS: In group B, staining for HSP47, HSP70, and collagen III in peritoneal tissues was faint, and only a few cells were positive for alpha-SMA and CD68. In contrast, HSP47, HSP70, and collagen III were expressed in areas of thickened connective tissues in fibrotic peritoneal specimens of CAPD patients. The expression level of HSP47, HSP70, collagen III, and alpha-SMA and the number of CD68-positive cells in group A2 were significantly higher than those in groups A1 and B. HSP47/HSP70-positive cells were mesothelial cells, adipocytes, and alpha-SMA-positive myofibroblasts. Furthermore, the expression level of HSP47 was significantly higher in peritoneal specimens from patients with refractory peritonitis than without it and was significantly higher in patients with more than 60 months of CAPD therapy than that in patients with less than 60 months of CAPD. CONCLUSION: Our results indicate that CAPD therapy may induce HSPs in the peritoneal tissue, and that peritonitis in CAPD patients may be associated with the progression of peritoneal sclerosis at least through HSP47 expression and chronic macrophage infiltration. Our data also suggest that the progression of peritoneal sclerosis in such patients is associated with deterioration of peritoneal ultrafiltration function.     

Interstitial expression of heat shock protein 47 and alpha-smooth muscle actin in renal allograft failure.

BACKGROUND: Tubulointerstitial inflammation and fibrosis are the main pathological features of chronic renal allograft rejection, which is characterized by accumulation of extracellular matrix protein. Heat shock protein 47 (HSP47), known as a collagen-specific stress protein, is thought to be a molecular chaperone during the processing and/or secretion of procollagen. HSP47 is thought to be involved in the progression of fibrosis, but its expression in chronic renal allograft rejection is still unknown. METHODS: We examined the expression of HSP47 together with that of alpha-smooth muscle actin (alpha-SMA), a marker of myofibroblasts, and CD68, a marker of macrophages, by immunohistochemistry in allograft kidney tissues. Uninvolved portions of surgically removed kidneys with tumours served as control tissue. RESULTS: Expression of HSP47 was detected in the interstitium of fibrotic regions of allograft kidneys. Cells positive for HSP47 were also stained for alpha-SMA and type I collagen, and the expression of HSP47 correlated with the degree of interstitial fibrosis. Furthermore, the expression of HSP47 correlated with the number of infiltrating macrophages. In contrast, HSP47 and alpha-SMA were not expressed in the control tissues, sections of 1 h post-transplantation biopsy specimens and acute allograft rejection without fibrosis. CONCLUSION: Our results suggest that HSP47 may contribute to the progression of interstitial fibrosis in allograft renal tissues.     

Pleiotrophin triggers inflammation and increased peritoneal permeability leading to peritoneal fibrosis

Long-term peritoneal dialysis induces peritoneal fibrosis with submesothelial fibrotic tissue. Although angiogenesis and inflammatory mediators are involved in peritoneal fibrosis, precise molecular mechanisms are undefined. To study this, we used microarray analysis and compared gene expression profiles of the peritoneum in control and chlorhexidine gluconate (CG)-induced peritoneal fibrosis mice. One of the 43 highly upregulated genes was pleiotrophin, a midkine family member, the expression of which was also upregulated by the solution used to treat mice by peritoneal dialysis. This growth factor was found in fibroblasts and mesothelial cells within the underlying submesothelial compact zones of mice, and in human peritoneal biopsy samples and peritoneal dialysate effluent. Recombinant pleiotrophin stimulated mitogenesis and migration of mouse mesothelial cells in culture. We found that in wild-type mice, CG treatment increased peritoneal permeability (measured by equilibration), increased mRNA expression of TGF-β1, connective tissue growth factor and fibronectin, TNF-α and IL-1β expression, and resulted in infiltration of CD3-positive T cells, and caused a high number of Ki-67-positive proliferating cells. All of these parameters were decreased in peritoneal tissues of CG-treated pleiotrophin-knockout mice. Thus, an upregulation of pleiotrophin appears to play a role in fibrosis and inflammation during peritoneal injury.     

Involvement of Lymphocyte Infiltration in the Progression of Mouse Peritoneal Fibrosis Model

Peritoneal fibrosis is a serious complication in patients with severe chronic kidney disease who are undergoing peritoneal dialysis (PD). One of the pathological characteristics of peritoneal fibrosis is the infiltration of macrophages in the thickened submesothelial compact zone. In addition, infiltration of lymphocytes, including T and B lymphocytes, is observed in the fibrotic peritoneum. However, the relationship between lymphocyte infiltration and progression of peritoneal fibrosis remains unclear. In this study, we investigated the role of lymphocytes in the development of peritoneal fibrosis induced by chlorhexidine gluconate (CG) by comparing the histological changes observed in severe combined immunodeficient (SCID) mice (largely lacking functional T and B lymphocytes) with those observed in wild-type (WT) mice. As expected, CG-injected WT mice showed a thickening of the submesothelial compact zone together with massive collagen deposition accompanied by increased numbers of infiltrating macrophages and T and B lymphocytes. In the peritoneum of SCID mice, the submesothelial compact zone was thicker and the number of macrophages and B lymphocytes was significantly higher than that observed in control immunodeficient and WT mice. In contrast, the number of T lymphocytes in the peritoneum of SCID mice was significantly lower than that in the peritoneum of WT mice. These results suggest that T and B lymphocytes modulate the process of peritoneal fibrosis via macrophage infiltration.     

Involvement of lymphocyte infiltration in the progression of mouse peritoneal fibrosis model

Peritoneal fibrosis is a serious complication in patients with severe chronic kidney disease who are undergoing peritoneal dialysis (PD). One of the pathological characteristics of peritoneal fibrosis is the infiltration of macrophages in the thickened submesothelial compact zone. In addition, infiltration of lymphocytes, including T and B lymphocytes, is observed in the fibrotic peritoneum. However, the relationship between lymphocyte infiltration and progression of peritoneal fibrosis remains unclear. In this study, we investigated the role of lymphocytes in the development of peritoneal fibrosis induced by chlorhexidine gluconate (CG) by comparing the histological changes observed in severe combined immunodeficient (SCID) mice (largely lacking functional T and B lymphocytes) with those observed in wild-type (WT) mice. As expected, CG-injected WT mice showed a thickening of the submesothelial compact zone together with massive collagen deposition accompanied by increased numbers of infiltrating macrophages and T and B lymphocytes. In the peritoneum of SCID mice, the submesothelial compact zone was thicker and the number of macrophages and B lymphocytes was significantly higher than that observed in control immunodeficient and WT mice. In contrast, the number of T lymphocytes in the peritoneum of SCID mice was significantly lower than that in the peritoneum of WT mice. These results suggest that T and B lymphocytes modulate the process of peritoneal fibrosis via macrophage infiltration.     

Glomerular epithelial-mesenchymal transdifferentiation in pauci-immune crescentic glomerulonephritis.

BACKGROUND: Among the cellular changes occurring in renal fibrosis, epithelial-mesenchymal cell transdifferentiation or transition (EMT) is a phenomenon characterized in epithelial cells by loss of epithelial markers and acquisition of mesenchymal phenotype and of fibrosing properties. METHODS: To test the hypothesis that EMT is involved in human pauci-immune crescentic glomerulonephritis (PICGN), we studied 17 renal biopsies from 11 PICGN patients for: (i) proliferating cell nuclear antigen (PCNA) and cell cycle inhibitors (cyclin-dependent kinase inhibitors) p27 and p57; (ii) cell lineage phenotype markers: podocalyxin, synaptopodin and GLEPP-1 for podocytes; CD68 for macrophagic epitope; CD3 for T lymphocytes; alpha-smooth muscle actin (alpha-SMA) for myofibroblasts; vimentin for mesenchymal cells; and cytokeratins (CKs) for parietal epithelial cells (PECs); (iii) glomerular fibrosis by labelling collagens I, III and IV, and heat-shock protein 47 (HSP47), a marker of collagen-synthesizing cells; and (iv) co-localization of alpha-SMA, CK and HSP47 using confocal laser microscopy. RESULTS: The crescent cells proliferated greatly. They did not express p27 and p57. Different cell lineage markers could be identified in crescents: the major component was made of 'dysregulated' PECs negative for CK, followed by PECs positive for CK, macrophagic cells and myofibroblasts. Furthermore, some cells co-expressed CK and alpha-SMA. This latter co-expression suggests a transitional phase in the dynamic phenomenon of EMT. Therefore, proliferative and dysregulated glomerular epithelial cells could be a possible cellular source of myofibroblasts via EMT. In addition, HSP47 labelled many crescent cells and frequently co-localized in CK-positive epithelial cells and in alpha-SMA-positive myofibroblasts, indicating that these cells were involved in glomerular accumulation of collagens. CONCLUSION: EMT is a transient cellular phenomenon present in glomeruli in human PICGN contributing to the formation of myofibroblasts from epithelial cells and to glomerular fibrosis.     

Localization of HSP47 in cisplatin-treated rat kidney: a possible role in tubulointerstitial damage

Background. A 47-kDa heat-shock protein (HSP47) is a major collagen-binding stress protein and is assumed to play an important role in the fibrotic process, but its role in cisplatin-induced tubulointerstitial fibrosis is not yet clear. To explore the possible role(s) of collagen-binding stress protein HSP47 in cisplatin-induced tubulointerstitial fibrosis, the expression of HSP47 was examined in cisplatin-treated rat kidneys. Methods. Eighteen male Wistar rats were divided into two groups; group I were age-matched controls and group II, animals were injected intraperitoneally with a single dose of cisplatin (6 mg/kg body weight). One hour after cisplatin injection, three rats from group II were killed along with control rats. The remaining rats in both groups were killed on the 7th, 14th, and 28th days of the experiment and the kidneys were collected for morphological and immunohistochemical study. The expression of collagen-binding HSP47 with various proteins implicated in phenotypic modulation (α-smooth muscle actin and vimentin) and fibrosis (type I and type III collagens) was examined in control and cisplatin-treated kidneys. Results. Cisplatin induced marked tubulointerstitial damage, including interstitial fibrosis, which was characterized by increased deposition of type I and type III collagens. Increased expression of HSP47 was also noted in and around the expanded interstitium in cisplatin-treated rats; by double-staining, HSP47-expressing cells were found to be α-smooth muscle actin-positive myofibroblasts and vimentin-positive tubular epithelial cells. In addition, colocalization of HSP47 and collagens was seen in and around the interstitial fibrosis in cisplatin-treated kidneys. Conclusion. From the results, we concluded that overexpression of HSP47 by phenotypically altered renal cells may play an important role in the excessive assembly of collagens and could thereby contribute significantly to the development of the tubulointerstitial fibrosis found in cisplatin-treated rat kidneys. Received: October 5, 1998 / Accepted: March 5, 1999     

Inhibition by an angiogenesis inhibitor, TNP-470, of the growth of a human hepatoblastoma heterotransplanted into nude mice

BACKGROUND/PURPOSE: The effect of TNP-470, an angiogenesis inhibitor, on the growth of a hepatoblastoma transplanted into nude mice was examined. METHODS: A hepatoblastoma obtained from a 3-year-old girl was serially transplanted into nude mice subcutaneously, and the transplant tumors of the seventh and eighth generations were used for experiments. Expression of various markers in the tumors was examined immunohistochemically. TNP-470 was injected subcutaneously every other day into tumor-bearing mice from 3 weeks after tumor transplantation. The proliferation of tumor cells and endothelial cells was estimated by means of the bromodeoxyuridine labeling index. RESULTS: The original hepatoblastoma showed the histology of the epithelial type, consisting of both the fetal and embryonal subtypes and was positively stained with anti-alpha-fetoprotein (AFP), anti-cytokeratin-19 and polyclonal anticarcinoembryonic antigen antibodies, and an antihuman hepatocyte antibody (hepatocyte paraffin 1). The transplant tumors consisted of solid nests of tumor cells with numerous vascular lakes of various sizes, and showed positive staining with all antibodies that reacted positively with the original hepatoblastoma. Injections of TNP-470 at the doses of 15 mg and 30 mg/kg body weight suppressed the tumor growth and the increase in the serum level of AFP dose dependently. Injections of TNP-470 also suppressed the proliferation of tumor cells and endothelial cells in the tumors. CONCLUSIONS: Hepatoblastomas maintained in nude mice retained the immunohistochemical characteristics of the original hepatoblastoma, and TNP-470 suppressed the growth of hepatoblastomas transplanted into nude mice. TNP-470 may be worth investigating further as to its usefulness as a therapy for hepatoblastomas.     

Effects of 1,25-dihydroxyvitamin D3 on the expression of connective tissue growth factor and heat shock protein 47 in peritoneum fibrosis rats

Objective To investigate the expression of connective tissue growth factor (CTGF) and heat shock protein 47 (HSP47) in peritoneum fibrosis rats, and the mechanism of 1,25-dihydroxyvitamin D3 [1,25-(OH)2-VitD3] in inhibiting the peritoneum fibrosis. Methods Adult male Sprague-Dawley rats were randomly divided into 3 groups: control group (n=8), model group (n=8) and 1,25-dihydroxyvitamin D3 group (VitD3, n=8). The model of peritoneum fibrosis rats were induced by daily intraperitoneally injection of 15% chlorhexidine gluconate (CHX) 0.2 ml/d with 0.1% glucose for 4 weeks. Rats in VitD3 group were also treated with 1,25-(OH)2-VitD3 [i.p. 6 ng?(100 g)-1?d-1]. Peritoneal transport function, renal function, peritoneum thickness and serum level of 25 hydroxyvitamin D3 were detected. In vitro, primary cultured peritoneal mesothelial cells were divided into control group, high glucose group (HG, 2.5%), CTGF siRNA intervention group (CTGF siRNA+HG), VitD3 intervention group (VitD3+HG) and combined intervention group (CTGF siRNA+VitD3+HG). Real-time PCR, Western blotting and immunofluorescence were applied to measure the expression of CTGF and HSP47, also ELISA was used to detect the protein level of FN in peritoneum and peritoneal mesothelial cells. Results Compared with control group, the peritoneal ultrafiltration in peritoneum fibrosis rats were significantly decreased (P＜0.05), the absorbance level of peritoneal fibrosis, peritoneum thickness, the rate of dialysate urea nitrogen and blood urea nitrogen (DUN/BUN) and the expressions of CTGF and HSP47 were increased (all P＜0.05). After application of 1,25-dihydroxyvitamin D3, peritoneal fibrosis lesion was significantly improved, the peritoneum thickness, the expressions of CTGF and HSP47 were decreased (all P＜0.05). In vitro, 2.5% high glucose induced-peritoneal mesothelial cells were respectively treated by CTGF siRNA, 1,25-(OH)2-VitD3 and combined interventions, the expression of FN, CTGF and HSP47 was significantly lower than that in high glucose group (all P＜ 0.05). Conclusions The expression of CTGF and HSP47 is significantly increased in peritoneal fibrosis rats. 1,25-(OH)2-VitD3 may ameliorate the progression of peritoneal fibrosis via reducing the expression of CTGF, decreasing the expression of HSP47 and FN.     

Mannose receptor 2 attenuates renal fibrosis

Mannose receptor 2 (Mrc2) expresses an extracellular fibronectin type II domain that binds to and internalizes collagen, suggesting that it may play a role in modulating renal fibrosis. Here, we found that Mrc2 levels were very low in normal kidneys but subsets of interstitial myofibroblasts and macrophages upregulated Mrc2 after unilateral ureteral obstruction (UUO). Renal fibrosis and renal parenchymal damage were significantly worse in Mrc2-deficient mice. Similarly, Mrc2-deficient Col4α3(-/-) mice with hereditary nephritis had significantly higher levels of total kidney collagen, serum BUN, and urinary protein than Mrc2-sufficient Col4α3(-/-) mice. The more severe phenotype seemed to be the result of reduced collagen turnover, because procollagen III (α1) mRNA levels and fractional collagen synthesis in the wild-type and Mrc2-deficient kidneys were similar after UUO. Although Mrc2 associates with the urokinase receptor, differences in renal urokinase activity did not account for the increased fibrosis in the Mrc2-deficient mice. Treating wild-type mice with a cathepsin inhibitor, which blocks proteases implicated in Mrc2-mediated collagen degradation, worsened UUO-induced renal fibrosis. Cathepsin mRNA profiles were similar in Mrc2-positive fibroblasts and macrophages, and Mrc2 genotype did not alter relative cathepsin mRNA levels. Taken together, these data establish an important fibrosis-attenuating role for Mrc2-expressing renal interstitial cells and suggest the involvement of a lysosomal collagen turnover pathway.     

Bone marrow‐derived mesenchymal stem cell attenuates skin fibrosis development in mice

Recent studies showed that mesenchymal stem cell (MSC) transplantation significantly alleviated tissue fibrosis; however, little is known about the efficacy on attenuating cutaneous scar formation. In this study, we established a dermal fibrosis model induced by bleomycin and evaluated the benefit of bone marrow‐derived mesenchymal stem cells (BM‐MSCs) on skin fibrosis development. Tracing assay of green fluorescent protein (GFP⁺)BM‐MSCs showed that the cells disappeared gradually within 24 hours upon administration, which hinted the action of BM‐MSCs in vivo was exerted in the initial phase of repair in this model. Therefore, we repeatedly transplanted syngeneic BM‐MSCs in the process of skin fibrosis formation. After 3 weeks, it was found that BM‐MSC‐treated lesional skin demonstrated a unanimous basket‐weave organisation of collagen arrangement similar to normal skin, with few inflammatory cells. In addition, lesional skin with BM‐MSC treatment exhibited a significant down‐regulation of transforming growth factor‐β1 (TGF‐β1), type I collagen and heat‐shock protein 47 (HSP47), with higher expression of matrix metalloproteinases (MMPs)‐2, ‐9 and ‐13. Further experiments showed that α‐smooth muscle actin (α‐SMA) positive cells, the most reliable marker of myofibroblasts, apparently decreased after BM‐MSC transplantation, which revealed that BM‐MSCs could attenuate myofibroblast proliferation and differentiation as well as matrix production. Taken together, these findings suggested that BM‐MSCs can inhibit the formation process of bleomycin‐induced skin fibrosis, alleviate inflammation and favour the remodelling of extracellular matrix.     

热休克蛋白47在转化生长因子β1诱导肾小管间质纤维化中的作用

目的 探讨热休克蛋白47（HSP47）在肾小管间质纤维化中的作用及其可能机制。 方法 常规培养人肾小管上皮细胞（HK-2）,分为对照组、转化生长因子β1（TGF-β1）组、HSP47-siRNA组。RT-PCR检测HSP47、胶原Ⅳ、纤连蛋白（FN）、组织型纤溶酶原激活物抑制剂1（PAI-1）的mRNA表达。Western印迹检测HSP47、胶原Ⅳ、FN蛋白表达。ELISA检测PAI-1的蛋白量。 结果 HK-2细胞有HSP47表达。不同浓度TGF-β1（0、2.5、5、10 μg/L）干预不同时间（12、24、48 h）时,HSP47基因和蛋白表达呈浓度和时间依赖性增高,10 μg/L TGF-β1干预HK-2细胞48 h时,HSP47 mRNA和蛋白表达最强。不同浓度 TGF-β1（0、5、10 μg/L）干预HK-2不同时间（12、24、48 h）时,胶原Ⅳ、FN 、PAI-1 mRNA和蛋白表达亦呈浓度和时间依赖性增高,10 μg/L TGF-β1作用48 h时,3者mRNA和蛋白表达最强。与TGF-β1组比较,HSP47-siRNA组的HSP47、胶原Ⅳ、FN、PAI-1 mRNA和蛋白表达都明显下调。 结论 HSP47可促进肾小管间质纤维化,其机制可能与上调胶原Ⅳ、FN、PAI-1表达有关。     

Epithelial-to-mesenchymal transition of mesothelial cells is an early event during peritoneal dialysis and is associated with high peritoneal transport

Ultrafiltration (UF) failure is a consequence of long-term peritoneal dialysis (PD). Fibrosis, angiogenesis, and vasculopathy are causes of this functional disorder after 3-8 years on PD. Epithelial-to-mesenchymal transition (EMT) of mesothelial cell (MC) is a key process leading to peritoneal fibrosis with functional deterioration. Our purpose was to study the peritoneal anatomical changes during the first months on PD, and to correlate them with peritoneal functional parameters. We studied 35 stable PD patients for up to 2 years on PD, with a mean age of 45.3+/-14.5 years. Seventy-four percent of patients presented loss of the mesothelial layer, 46% fibrosis (>150 microm) and 17% in situ evidence of EMT (submesothelial cytokeratin staining), which increased over time. All patients with EMT showed myofibroblasts, while only 36% of patients without EMT had myofibroblasts. The number of peritoneal vessels did not vary when we compared different times on PD. Vasculopathy was present in 17% of the samples. Functional studies were used to define the peritoneal transport status. Patients in the highest quartile of mass transfer area coefficient of creatinine (Cr-MTAC) (>11.8 ml min(-1)) showed significantly higher EMT prevalence (P=0.016) but similar number of peritoneal vessels. In the multivariate analysis, the highest quartile of Cr-MTAC remained as an independent factor predicting the presence of EMT (odds ratio 12.4; confidence interval: 1.6-92; P=0.013) after adjusting for fibrosis (P=0.018). We concluded that, during the first 2 PD years, EMT of MCs is a frequent morphological change in the peritoneal membrane. High solute transport status is associated with its presence but not with increased number of peritoneal vessels.     

Synergistic Antitumor Effect of an Angiogenesis Inhibitor (TNP-470) and Tumor Necrosis Factor in Mice

Purpose We investigated the potentiation of combination therapy using tumor necrosis factor (TNF) with TNP-470, a potent angiogenesis inhibitor. Methods We evaluated the antitumor effect in vivo against subcutaneous (s.c.) MC38 mouse colon adenocarcinoma tumors in C57BL/6 mice. The mice were treated with a single bolus injection via the tail vein of 3 or 8 μg rhTNF in 0.5% bovine serum albumin/normal saline (BSA/NS), or with 0.5% BSA/NS alone as a control, with or without TNP-470 pretreatment, given as 30 or 60 mg/kg × 2 days, s.c. DNA synthesis in human umbilical endothelial cells (HUVEC) was assessed by [³H]thymidine uptake after incubation with TNF, with or without TNP-470. Results The antitumor effect of TNP-470 pretreatment combined with 3 μg recombinant human (rh) TNF injection resulted in an 80% reduction of tumor volume compared with the control. This was significantly better than that induced by 3 μg rhTNF alone (P < 0.005). DNA synthesis in HUVEC was inhibited by TNF with TNP-470 in a dose-dependent manner, but there was no enhanced effect against MC38 in vitro. Conclusions These results suggest that the combination of the angiogenesis inhibitor TNP-470 and TNF might have a synergistic antitumor effect on solid tumors in vivo.     

Advanced glycation end-products and peritoneal sclerosis

Long-term continuous ambulatory peritoneal dialysis (CAPD) often causes peritoneal fibrosis and sclerosis with a loss of function, and some CAPD patients develop sclerosing encapsulating peritonitis. Glucose-based peritoneal dialysis fluids readily produce glucose degradation products by heat sterilization, and glucose degradation products accelerate the formation of advanced glycation end-products (AGE) in the peritoneal cavity. The accumulation of AGE is observed in peritoneal mesothelial and submesothelial layers in CAPD patients, accompanied by enhanced expression of various growth factors and peritoneal thickening. The expression of transforming growth factor-beta1 (TGF-beta1), macrophage-colony stimulating factor, and vascular endothelial growth factor (VEGF) is distributed in the peritoneum similarly to that of AGE. In CAPD patients with low ultrafiltration (UF) capacity, peritoneal membrane is thickened owing to an increase in the number of cells such as fibroblasts and macrophages and collagen in the submesothelial layer. AGE is detected in the fibroblasts and macrophages as well as degenerated collagen. These cells in the submucosal layer are almost positive for the receptor for AGE (RAGE) and uptake AGE. The intensity of AGE accumulation and the expression of growth factors are associated with the severity of UF impairment. In fact, the accumulation of AGE and the expression of growth factors are recognized most markedly in the peritoneum of CAPD patients with low UF and sclerosing encapsulating peritonitis. In conclusion, long-time CAPD with heat-sterilized peritoneal dialysis fluid promotes AGE accumulation in the peritoneal membrane and alteration in peritoneal cell function and dialysis quality, followed by peritoneal sclerosis, and, finally, sclerosing encapsulating peritonitis.     

Outcomes after lower-extremity reconstruction in DRGs 478 and 479

TNP-470 is a synthetic analogue of fumagillin that acts as a potent angiogenesis inhibitor. Recently, our laboratory demonstrated that systemic administration of TNP-470 (5.0 mg/kg) decreased the rate of cutaneous wound healing by greater than 20%. In this study, we tested the hypothesis that TNP-470 interferes with the wound repair-stimulating action of basic fibroblast growth factor (bFGF) by competing with endogenous bFGF for its binding sites on the receptor protein. The influence of TNP-470 was examined in vitro in a ligand competition assay of high- and low-affinity receptor binding to (125)I-bFGF in NIH/3T3 cells. Results demonstrated that recognition of (125)I-bFGF by low-affinity growth factor binding sites was significantly decreased (P < 0.01) in the presence of TNP-470. However, TNP-470 inhibition of radiolabeled bFGF binding to high-affinity sites was not significantly affected (P = 0.07). In view of recent studies demonstrating that the low-affinity receptors of bFGF were heparan sulfate proteoglycans, we suggest that the influence of TNP-470 on diminished wound healing is due to its direct recognition by these molecules.     

TNP-470, an angiogenesis inhibitor, attenuates the development of allograft vasculopathy

Fischer 344 rat recipients of Lewis allografts were treated with TNP-470, a synthetic fumagillin derivative and a well-established angiogenesis inhibitor. TNP-470 alone resulted in some prolongation of graft survival as compared with untreated recipients, but all grafts ultimately failed. In contrast, treatment with cyclosporine (CsA) from day 0 to 30 resulted in prolonged graft survival and marked cardiac allograft vasculopathy (CAV) by histology (mean score 2.28+/-0.2). There were many neovessels within the intima of CAV lesions. When TNP-470 was administered in combination with CsA from day 0 to 30, the degree of CAV was similar to that with CsA alone (mean score 2.22+/-0.26). However, when TNP-470 was administered from day 30 to 120 after discontinuation of CsA, there was a marked reduction in the degree of CAV (mean score 1.08+/-0.11). Therefore, TNP-470 interrupts the progression of CAV when given late but does not prevent its development when given immediately posttransplantation.     

Interstitial expression of heat-shock protein 47 correlates with capillary deposition of complement split product C4d in chronic allograft nephropathy

BACKGROUND: Chronic allograft nephropathy (CAN), associated with late-allograft dysfunction is caused by alloantigen-dependent and -independent mechanisms, and eventually leads to interstitial fibrosis (ci). Activation of complement cascade is considered to be a poor prognostic marker of graft survival. This study was designed to examine the relationship between the expression of C4d and heat-shock protein 47 (HSP47, a collagen-specific chaperone) in the development of interstitial fibroproliferative lesions in CAN. METHODS: Sixty-three renal allograft biopsy specimens, obtained from 48 patients, were examined for the expression of C4d, HSP47, CD68 and alpha-smooth muscle actin (alpha-SMA) by immunohistochemistry. Double-staining was performed to determine the colocalization of C4d and HSP47. The relationship of between the expression of C4d, HSP47, CD68 and alpha-SMA and the clinical and histopathological parameters were statistically analysed. RESULTS: No expression of C4d was noted in the tubulointerstitium including peritubular capillary (PTC) of the control kidney. C4d was expressed in PTC in one-third of allograft renal tissues with morphological evidences of CAN. The interstitial cells around the fibrotic areas of the PTC of CAN were positive for the expression of HSP47. The deposition of C4d in PTC correlated with interstitial expression of HSP47 around the PTC. Most HSP47 expressing cells were phenotypically altered myofibroblasts, as determined by the dual staining of alpha-SMA. CONCLUSIONS: The increased expression of HSP47 positively correlated with the expression of C4d in PTC, and might contribute to the progression of interstitial ci in CAN.     

TNP-470 reduces collagen and macrophage accumulation in expanded polytetrafluoroethylene tube implants.

BACKGROUND: TNP-470 is a potent angiogenic inhibitor that has been demonstrated to decrease the rate of cutaneous wound healing. This study investigated the effect that TNP-470 has upon collagen growth and macrophage infiltration into expanded polytetrafluoroethylene (e-PTFE) tube implants. METHODS: e-PTFE tubes (1.0 cm in length) were implanted into the dorsum of male Swiss-Webster mice (8-10 weeks old). TNP-470 was administered subcutaneously in doses of 0.5, 1.0, or 5.0 mg/kg for determination of hydroxyproline accumulation on day 18 after implantation. Additionally, TNP-470 was administered at 5.0 mg/kg for determination of macrophage infiltration on days 4, 8, 13, and 18 after implantation. RESULTS: Administration of TNP-470 at doses of 1.0 and 5.0 mg/kg on days 0, 2, and 4 significantly (P < 0.05) decreased hydroxyproline accumulation in e-PTFE implants on day 18 after implantation. Administration of 0.5 mg/kg of TNP-470 yielded no significant difference vs the vehicle control (P < 0.81). Additionally, administration of TNP-470 at 5.0 mg/kg on days 0, 2, and 4 significantly (P < 0.05) decreased macrophage infiltration into e-PTFE implants on day 4 after implantation. There was also a significantly (P < 0.05) increased percentage of macrophages in the e-PTFE implants on day 13 after wounding. No significant differences were observed between the experimental and control groups on days 8 and 18. CONCLUSIONS: Administration of TNP-470 significantly decreases hydroxyproline accumulation in e-PTFE implants. These data suggest that while TNP-470 is administered, macrophage infiltration is impaired; however, upon discontinuing administration, macrophage infiltration increases. Possible mechanisms to account for these findings are discussed.