Papillary carcinoma of the thyroid with exuberant nodular fasciitis-like stroma

 We describe a rare case of papillary carcinoma with extensive proliferation of stromal cells. The stromal cells were immunocytochemically positive for vimentin, α-smooth muscle actin and desmin, but negative for cytokeratin, epithelial membrane antigen, S-100, thyroglobulin and CD34. These results and the ultrastructure of the stromal cells, which exhibited the characteristics of both fibroblasts and smooth muscle cells, indicated an origin from myofibroblasts. We conclude that myofibroblastic proliferation may contribute to the stromal response in the slow growth of the papillary carcinoma. Received: 29 August 1996 / 26 May 1997     

Immunohistochemical characterization of fibroblast subpopulations in normal peritoneal tissue and in peritoneal dialysis-induced fibrosis

Peritoneal fibrosis is one of the most common morphological changes observed in continuous ambulatory peritoneal dialysis (CAPD) patients. Both resident fibroblasts and new fibroblast-like cells derived from the mesothelium by epithelial-to-mesenchymal transition are the main cells involved fibrogenesis. In order to establish markers of peritoneal impairment and pathogenic clues to explain the fibrogenic process, we conducted an immunohistochemical study focused on peritoneal fibroblasts. Parietal peritoneal biopsies were collected from four patient groups: normal controls (n=15), non-CAPD uremic patients (n=17), uremic patients on CAPD (n=27) and non-renal patients with inguinal hernia (n=12). To study myofibroblastic conversion of mesothelial cells, -smooth muscle actin (SMA), desmin, cytokeratins and E-cadherin were analyzed. The expression of CD34 by fibroblasts was also analyzed. Fibroblasts from controls and non-CAPD uremic patients showed expression of CD34, but no myofibroblastic or mesothelial markers. The opposite pattern was present during CAPD-related fibrosis. Expression of cytokeratins and E-cadherin by fibroblast-like cells and -SMA by mesothelial and stromal cells supports that mesothelial-to-myofibroblast transition occurs during CAPD. Loss of CD34 expression correlated with the degree of peritoneal fibrosis. The immunophenotype of fibroblasts varies during the progression of fibrosis. Myofibroblasts seem to derive from both activation of resident fibroblasts and local conversion of mesothelial cells.Manuel López-Cabrera and Rafael Selgas contributed equally to the article.     

Immunohistochemical expression of myofibroblasts,TGF-β1 and IFN-γ in oral fibrous lesions

ObjectiveAnalyze the presence of myofibroblasts (MFBs) in oral fibrous lesions and investigate TGF-β1 and IFN-γ expression by immunohistochemistry during their differentiation.DesignTwenty giant cell fibromas (GCFs), 20 fibromas (FIBs), and 20 fibrous hyperplasias (FHs) were selected. To evaluate the presence of MFBs, anti-α-SMA-immunoreactive cells were quantified in connective tissue. TGF-β1 and IFN-γ expressions were evaluated in epithelial and connective tissue by determining the percentage of immunoreactive cells.ResultsHigher MFBs concentrations were observed in GCFs (median of 20.00), followed by FHs (15.00) and FIBs (14.00) (P = 0.072). No significant correlation between TGF-β1 or IFN-γ immunoexpression and the number of MFBs in oral fibrous lesions was observed (P > 0.05).ConclusionsThe higher density of MFBs found in GCFs, followed by FHs and FIBs, reaffirms the fibrogenic role of these cells, while the higher concentrations detected in GCFs, including evidence of giant MFBs, also suggest a role in the neoplastic behavior of these lesions. No correlation was observed between TGF-β1 and IFN-γ in the myofibroblastic transdifferentiation process of the analyzed lesions.     

Regulation of Migration of Human Colonic Myofibroblasts

Background and Aim: The migration of mesenchymal cells to areas of mucosal or submucosal tissue damage is an essential factor for wound healing in the intestine. Thus far, neither migration inducing factors nor signal transduction cascades involved in the migration of colonic myofibroblasts (CMF) have been studied in detail. Methods: Primary CMF were isolated from the mucosa of surgical specimens or endoscopic biopsies. Migration assays of CMF were performed in the modified 48-well Boyden chamber. Secreted growth factors were quantified by ELISA. Results: CMF secrete autocrine or paracrine migration stimulating factors. Culture supernatant of CMF collected after 24, 48, and 72 h (=conditioned media) stimulated the migration of CMF ( 48.9 &#45 4.5; 60.3 &#45 5.3 and 67.8 &#45 6.4 cells/hpf, respectively). Heating of conditioned media to 95°C or addition of cycloheximide during the conditioning period abolished migration. Addition of PDGF-AB (2.5-50 ng/ml) or IGF-I (10-300 ng/ml) to CMF conditioned media further increased the migration of CMF to a maximum of 177 and 160%, respectively, when compared to the migration induced by conditioned medium alone. Addition of EGF (2.5-50 ng/ml) or TGF- &#103 1 (1-50 pg/ml) caused an increased CMF migration up to 139 and 128%, respectively. MCP-1 (5-50 ng/ml) and bFGF (10-200 ng/ml) had no effect on CMF migration. Conclusion: The growth factors PDGF-AB, IGF-I, EGF and TGF- &#103 1 stimulate the migration of CMF. However, factors secreted by CMF are essential for their ability to migrate in response to these growth factors. The identification of physiologically relevant migration inducing factors may help to elucidate the network of interactions and the complex mechanisms involved in intestinal wound healing or fibrosis.     

肌成纤维细胞凋亡与肺纤维化

成纤维细胞受到各种刺激后可发生活化。并进而转化为表达α平滑肌肌动蛋白的肌成纤维细胞。转化生长因子β可抑制成纤维细胞调亡,而羟甲基戊二酸单酰辅酶A还原酶抑制剂等可促进成纤维细胞的凋亡。肌成纤维细胞能诱导肺泡上皮细胞的凋亡,促进肺纤维化的发生。     

Ac-SDKP经HSP27调节锌指蛋白而抑制肺上皮细胞-间质转化

目的:探讨N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸(Ac-SDKP)是否通过抑制热休克蛋白27(heat-shock protein 27,HSP 27)的表达,进而抑制锌指蛋白SNAI1、SNAI2的表达,而发挥阻抑转化生长因子(TGF)-β1诱导的人肺泡Ⅱ型上皮细胞向间质细胞(肌成纤维细胞)的转化以及Ⅰ型、Ⅲ型胶原蛋白的表达。方法:激光共聚焦检测TGF-β1诱导的人肺泡Ⅱ型上皮细胞向肌成纤维细胞转化中HSP27及SNAI1、SNAI2蛋白的共定位表达;real-time PCR法检测HSP27、SNAI1和SNAI2 mRNA的表达;Western blotting法检测HSP27、SNAI1、SNAI2和Ⅰ型、Ⅲ型胶原蛋白的表达,以及转染HSP27干扰质粒后SNAI1、SNAI2蛋白及Ⅰ型、Ⅲ型胶原蛋白表达的变化。结果:与对照组相比,TGF-β1刺激组HSP27、SNAI1、SNAI2及Ⅰ型、Ⅲ型胶原蛋白表达增强;给予Ac-SDKP干预后,HSP27、SNAI1、SNAI2及Ⅰ型、Ⅲ型胶原蛋白表达明显降低,差异有统计学意义。用HSP27的干扰质粒转扰细胞后,SNAI1、SNAI2及Ⅰ型、Ⅲ型胶原蛋白表达降低,其中SNAI1和Ⅰ型、Ⅲ型胶原蛋白的表达与TGF-β1刺激组比较差异有统计学意义。这与Ac-SDKP干预的结果相似。结论:Ac-SDKP能够通过对HSP27表达的调节,降低锌指蛋白SNAI1和SNAI2的表达,进而抑制肺泡Ⅱ型上皮细胞向肌成纤维细胞的转化及胶原蛋白的合成。     

MYOFIBROBLAST: A PROGNOSTIC MARKER AND TARGET CELL IN PROGRESSIVE RENAL DISEASE

Myofibroblasts play an important role in many tissue injuries, and particularly in renal disease. The myofibroblast differentiation is an early event in the development of fibrosis. Myofibroblast-like cells express smooth muscle (SM) cytoskeletal markers (α-SM actin in particular) and participate actively in the production of extracellular matrix. Identification of early risk factors, particularly histological criteria, could be useful to identify patients at risk of progressive renal failure and needing a treatment. The evaluation of myofibroblast differentiation in renal tissue may reflect the intensity of tissue injury, predict long term outcome of chronic renal disease and help physicians to select therapeutic choices. More than a disease activity indicator, myofibroblasts appear to be a pivotal target for future therapies in progressive renal disease.     

犬骨髓间充质干细胞体外分离、诱导成纤维细胞的实验研究

目的探讨体外稳定诱导骨髓间充质干细胞(BMSC)分化为成肌纤维细胞和成纤维细胞的方法,为构建组织工程瓣膜提供种子细胞。方法应用Percoll(密度1·073g/ml)淋巴细胞分离液分离健康犬骨髓标本,取分离的BMSC,在低糖改良Eagles培养液中培养,并用免疫组织化学的方法做细胞表型鉴定,然后用条件培养基对第2、3代细胞进行诱导分化,并用层黏连蛋白单抗对诱导后的细胞做免疫组织化学鉴定。并对诱导后细胞进行冻存,7d后复苏观察细胞的生长、增殖及功能。结果经Percoll液分离的骨髓单核细胞,经贴壁培养后,其表型为波形蛋白阳性、α平滑肌肌动蛋白阳性、CD3-4、层黏连蛋白阴性;诱导后细胞表达层黏连蛋白,阳性细胞数可达(50±3)%;诱导后BMSC经冻存复苏后,细胞复苏率(85±3)%,复苏后细胞生长、增殖旺盛,功能不受影响。结论BMSC体外能定向诱导分化为成肌纤维细胞和成纤维细胞,并符合种子细胞的要求。     

大鼠肾皮质成肌纤维细胞的体外培养

目的建立肾脏成肌纤维细胞的培养方法，为肾脏纤维化的发病机制和防治措施体外研究提供细胞技术平台。方法采用肾皮质组织块接种培养法，培养的细胞通过相差显微镜观察形态、电镜下观察细胞器，细胞免疫化学染色检测细胞表型标记蛋白等进行鉴定。同时检测细胞对不同细胞因子的生长反应。结果培养的细胞呈梭形，单个核，多突起，表达波形蛋白（vimentin）和平滑肌肌动蛋白（α，SMA），不表达主要存在于血管内皮细胞的抗原上皮氨基肽酶P（EAP），不表达角蛋白（cytokerafin）和结蛋白（desmin）。细胞可以传代至5代，并且保持成肌纤维细胞表型。转化生长因子β1、结缔组织生长因子刺激细胞增殖，而γ-干扰素对细胞无增殖效应。结论原代培养细胞为成肌纤维细胞并且可以传代，具备对细胞因子的生长调节反应，为后续实验提供了基础。