Animals ; Arthritis, Experimental ; metabolism ; pathology ; Breast Neoplasms ; pathology ; Cadherins ; metabolism ; physiology ; Cell Movement ; Female ; Fibroblasts ; cytology ; pathology ; Humans ; Macrophages ; cytology ; pathology ; Neoplasm Invasiveness ; Synovial Membrane ; cytology ; metabolism ; pathology

Bone Marrow Cells ; cytology ; Fibroblasts ; cytology ; metabolism ; Fibrosis ; Humans ; Myocardium ; pathology

Epithelial-mesenchymal transition (EMT) is a process by which fully differentiated epithelial cells undergo a phenotypic conversion and assume a mesenchymal cell phenotype, including elongated morphology, enhanced migratory and invasiveness capacity, and greatly increased production of extracellular matrix (ECM) components. The EMTs associated with wound healing, tissue regeneration, and organ fibrosis are termed as type 2 EMT. Over the past two decades, emerging evidence suggested that injured epithelial cells, via type 2 EMT, may serve as important sources of fibroblasts and contribute to organ fibrosis, such as kidney, liver, lung and eyes. There is perhaps no doubt that adult epithelial cells can undergo EMT in vitro in response to transforming growth factor (TGF)-β1 and other inflammatory or pro-fibrotic stimuli. However, whether type 2 EMT really occurs in vivo, whethers it is actually a source of functional and activated interstitial fibroblasts and whether it contributes to tissue fibrosis have already been the subjects of heated debate. In this review, we will describe the main features of EMT, the major findings of type 2 EMT in vitro, the evidences for and against type 2 EMT in vivo and discuss the heterogeneity and pitfalls of the techniques used to detect EMT during fibrotic diseases. We suggest that in order to ascertain the existence of type 2 EMT in vivo, different proper phenotype markers of epithelial and mesenchymal cells should be jointly used and cell lineage tracking techniques should be standardized and avoid false positives. Finally, we believe that if EMT really occurs and contributes to tissue fibrosis, efforts should be made to block or reverse EMT to attenuate fibrotic process.
Animals ; Epithelial-Mesenchymal Transition ; physiology ; Fibroblasts ; cytology ; metabolism ; Fibrosis ; metabolism ; pathology ; Humans

OBJECTIVETo investigate the role of lung fibroblast activation in radiation-induced lung injury.

METHODSThirty-five male Wistar rats were exposed to a single-dose 30 Gy irradiation of the right hemithorax or sham right lung irradiation. At 1, 7, 14, 28, 56 or 84 days after the irradiation, the rats were sacrificed for examination of alpha-smooth muscle actin (alpha-SMA) expression in the bilateral lung tissues using immunohistochemistry.

RESULTSalpha-SMA expression in fibroblast increased significantly in the out-field and in-field lung tissues within 24 h after irradiation after the irradiation (P<0.001).

CONCLUSIONActivation of the lung fibroblasts occurred within 24 h after irradiation and found in ont-field and in-field lung tissues, suggesting that radiation-induced lung injury may not have an obvious latency.

Actins ; genetics ; metabolism ; Animals ; Fibroblasts ; metabolism ; pathology ; Lung ; cytology ; pathology ; Male ; Radiation Injuries ; pathology ; Rats ; Rats, Wistar

OBJECTIVETo investigate the origin of myofibroblasts in oral submucous fibrosis.

METHODSThe oral keratinocytes and fibroblasts were isolated and cultured. The expression of the alpha-smooth muscle actin in the fibroblasts was examined by immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTSNo difference was found in expression of alpha-smooth muscle actin between the fibroblasts that were directly stimulated by arecoline and the control. The expression of alpha-smooth muscle actin in the keratinocyte and fibroblast-cocultured group was higher than in the control group, and higher in fibroblasts cocultured with keratinocytes preprocessed by arecoline than in fibroblasts cocultured with keratinocytes without preprocessed by arecoline.

CONCLUSIONSThe differentiation of myofibroblasts from fibroblasts in oral submucous fibrosis might be induced by the interaction of arecoline and keratinocyte.

Actins ; metabolism ; Arecoline ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Coculture Techniques ; Fibroblasts ; cytology ; metabolism ; Humans ; Keratinocytes ; cytology ; Mouth Mucosa ; cytology ; Oral Submucous Fibrosis ; metabolism ; pathology

The genesis and development of leukemia not only associate to intrinsic factors, but also relate with the fibrous hyperplasia in the bone marrow. This review mainly focuses on the interaction between fiber-producing cells and leukemia cells, the relationship between fibrous hyperplasia and prognosis of leukemia, the regulation of TGF-beta, PDGF and other cytokines, the underlying mechanism of fibrous hyperplasia so as to explore the potential therapeutic targets for improving the prognosis of leukemia.
Bone Marrow ; pathology ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Cytokines ; metabolism ; Fibroblasts ; cytology ; Humans ; Leukemia ; pathology ; Platelet-Derived Growth Factor ; metabolism ; Transforming Growth Factor beta ; metabolism

OBJECTIVETo observe the effect of tetrandrine on activity of collagenase derived from human hypertrophic scar for the sake of clarifying the mechanism as tetrandrine acting on scar.

METHODSThe experimental concentration was controlled below that of cell proliferation inhibited, SDS-PAGE electrophoresis was adopted to separate collagenase from extracellular matrix, and then activated by trypsin analyzed the activity of collagenase with density scanning apparatus. At the same time quantity of extracellular collagen was measured using improved chloraseptine T oxidizing assay, moreover analyzed correlation between activity of collagenase and quantity of extracellular collagen.

RESULTSIn the concentration below the lever of inhibiting fibroblast proliferation, the total activity of collagenase could be significantly increased by tetrandrine with dosage-dependence associated with quantity of extracellular collagen reduced, which was much greater than that of triamcinolone.

CONCLUSIONIncreasing activity of collagenase on degradation of collagen even in a lower concentration was one of the mechanisms of tetrandrine treating hypertrophic scar.

Benzylisoquinolines ; pharmacology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cicatrix, Hypertrophic ; metabolism ; pathology ; Collagenases ; metabolism ; Fibroblasts ; cytology ; Humans

OBJECTIVETo study the effect of substrate stiffness on proliferation, migration of fibroblast and integrin β(1) expression in fibroblast.

METHODSFibroblasts were inoculated on silicon substrate with stiffness of (16.2 ± 0.5), (19.8 ± 1.1), and (200.1 ± 2.6) kPa. After being cultured for 5 days or 6 days, cells were counted and cell proliferative activities (recorded as absorbance value) were assessed with methyl thiazolyl blue (MTT). After being cultured for 3 days, cell cycle was detected and proliferation index (PI) was calculated. The cell scratch test was used for determination of cell migration rate on post scratch day (PSD) 0 (the day of scratch), 1, 2, and 3. After being cultured for 2 days, the expression of integrin β(1) was determined by flow cytometry with fluorescence. Data were processed with one-way analysis of variance.

RESULTS(1) The proliferative speed and proliferative activity of fibroblasts were all increased along with the increase in substrate stiffness. PI of fibroblasts inoculated on silicon substrate with stiffness of (16.2 ± 0.5), (19.8 ± 1.1), and (200.1 ± 2.6) kPa was respectively 24.8%, 27.4%, 32.4%. On PSD 2, migration rate of fibroblasts inoculated on silicon substrate with stiffness of (19.8 ± 1.1) and (200.1 ± 2.6) kPa was respectively (91.4 ± 5.1)%, (100.0 ± 1.3)%, which were higher than that of fibroblasts inoculated on silicon substrate with stiffness of (16.2 ± 0.5) kPa [(55.8 ± 6.8)%, with F value respectively 3.5, 4.0, P values all below 0.01]. (3) The expression rate of integrin β(1) in fibroblasts inoculated on silicon substrate with stiffness of (16.2 ± 0.5) kPa was the lowest (43.22%), and that in fibroblast inoculated on silicon substrate with stiffness of (200.1 ± 2.6) kPa was the highest (81.26%).

CONCLUSIONSSubstrate stiffness may have a great effect on proliferation and migration of fibroblast during the process of wound healing and scar formation, which can be related to regulation of integrin β(1) expression.

Cell Movement ; Cell Proliferation ; Cells, Cultured ; Fibroblasts ; cytology ; metabolism ; pathology ; Humans ; Integrin beta1 ; metabolism ; Mechanical Phenomena ; Silicon

OBJECTIVETo imitate tumor microenvironment in vivo through construction of two-layer cell spheroid as a three-dimensional tumor model, and to validate its application in the study of Cx43 expression in colorectal cancer cell-fibroblast interactions and colorectal cancer progression.

METHODSThe two-layer cell spheroid was constructed from SW620 colorectal cancer cells and HELF fibroblasts. The expression of Cx43 in the spheroid was detected by immunocytochemistry. The expression of Cx43 in cultured SW620 cells with or without co-cultured fibroblasts was detected by immunocytochemistry and immunofluorescence. The expression of Cx43 in colorectal cancer tissue was detected by immunohistochemistry.

RESULTSThe spheroid showed well-defined cellular morphology and clear boundary between two cell lines.Significant expression of Cx43 was found along the boundary.SW620 cells had no expression of Cx43 when cultured alone, while the expression of Cx43 was induced upon co-culturing with fibroblasts.In the colorectal cancer tissue, expression of Cx43 was minimal in the centre of tumor in contrast to an upregulated expression at invasive front.

CONCLUSIONSThe two-layer cell spheroid is an observable and sensitive model for cell-cell interaction for studies of tumor microenvironment.It can simulate colorectal cancer cell-fibroblast interactions through up-regulation of Cx43 expression.

Cell Communication ; Cell Line, Tumor ; Coculture Techniques ; Colorectal Neoplasms ; metabolism ; pathology ; Connexin 43 ; metabolism ; Fibroblasts ; cytology ; Humans ; Spheroids, Cellular ; cytology ; metabolism ; Tumor Microenvironment ; Up-Regulation

OBJECTIVETo investigate the expression of extracellular matrix metalloproteinase inducer gene (EMMPRIN) regulated by the interactions between fibroblasts and colon cancer cells, and to study its role in the invasion and metastasis of colon cancer.

METHODSColon cancer cells (SW480) were co-cultured with fibroblasts (HELF) in RPMI 1640 media for 0, 12, 24 and 48 hours. The expression of EMMPRIN in SW480 cells and HELF cells was documented by RT-PCR and immunocytochemistry.

RESULTSThe mRNA and protein expressions of EMMPRIN in SW480 cells were remarkably increased by the co-culturing with HELF cells. Although without the endogenous expression, HELF cells began to express EMMPRIN in a time-dependent manner after being co-cultured with SW480 cells.

CONCLUSIONSIntercellular interactions between colon cancer cells and fibroblasts not only up-regulate the EMMPRIN expression in SW480 cells, but also induce its expression in HELF cells. Such interactions may play a crucial role in the invasion and metastasis of colon cancer.

Basigin ; biosynthesis ; genetics ; Cell Line, Tumor ; Cells, Cultured ; Coculture Techniques ; Colonic Neoplasms ; metabolism ; pathology ; Fibroblasts ; cytology ; metabolism ; Humans ; Lung ; cytology ; RNA, Messenger ; metabolism