OBJECTIVETo study the relationship between the morphologic mechanism of human embryonic epidermic cells and mesenchymal-epithelial transformation (MET) and its modulation factor.

METHODSMorphological occurrence of epidermis was detected with histologic methods in earlier period [estimated gestational age (EGA) 6-14 weeks] human embryonic skin samples. At the same time, the characteristic expression and their distribution markers of mesenchymal cells [vimentin and alpha-smooth muscle actin (alpha-SMA)], embryonic specific epidermic protein CK8&18, specific protein of epidermic stem cell CK19, transforming growth factor-beta1) (TGF-beta1) and its receptor (TGFbetaRI) in embryonic epidermis were examined with immunohistochemistry and indirect-immunofluorescent doble-labelling method.

RESULTSDuring EAG 6-8 weeks, ectodermal cells containing Vim+/alpha-SMA(-) were found to transform into epidermal stem cells with CK8&18+/CK19+. In ectodermal cells, protein expression density of TGFbetaRI was moderate (+ +), while positive signal of TGFbeta1 was weak (+/-). After EGA10 weeks, epidermal cells showed typical morphological characteristics.

CONCLUSIONSAt EGA 6-8 weeks, human embryonic skin epidermal cells began to form through MET, in which the signal pathway mediated by TGFbetaRI might play important roles, but the role of TGFbeta1 need to be further studied.

Cell Differentiation ; physiology ; Epidermis ; cytology ; embryology ; Epithelial Cells ; cytology ; Humans ; In Vitro Techniques ; Mesoderm ; cytology ; Receptors, Transforming Growth Factor beta ; metabolism ; Transforming Growth Factor beta1 ; metabolism

The purpose of this study was to explore the role of epithelial-mesenchymal transition in the pathogenesis of hepatolithiasis. Thirty-one patients with primary hepatolithiasis were enrolled in this study. Expressions of E-cadherin, alpha-catenin, alpha-SMA, vimentin, S100A4, TGF-beta1 and P-smad2/3 in hepatolithiasis bile duct epithelial cells were examined by immunohistochemistry staining. The results showed that the expressions of the epithelial markers E-cadherin and alpha-catenin were frequently lost in hepatolithiasis (32.3% and 25.9% of cases, respectively), while the mesenchymal markers vimentin, alpha-SMA and S100A4 were found to be present in hepatolithiasis (35.5%, 29.0%, and 32.3% of cases, respectively). The increased mesenchymal marker expression was correlated with decreased epithelial marker expression. The expressions of TGF-beta1 and P-smad2/3 in hepatolithiasis were correlated with the expression of S100A4. These data indicate that TGF-beta1-mediated epithelial-mesenchymal transition might be involved in the formation of hepatolithiasis.
Adult ; *Bile Ducts/cytology/metabolism/pathology ; Biological Markers/*metabolism ; Cell Differentiation/*physiology ; Epithelial Cells/cytology/*physiology ; Epithelium/physiology ; Female ; *Gallstones/metabolism/pathology ; Humans ; Liver Diseases/metabolism/*pathology ; Male ; Mesoderm/cytology/*physiology ; Middle Aged

OBJECTIVETo study the characteristics of dermal mesenchymal stem cells (DMSC), and explore whether they could enhance hematopoiesis recovery in vivo as well as facilitate proliferation and differentiation of hematopoietic cells in vitro.

METHODSMultipotential stem cells from the murine dermal mesenchyme were dissociated and cultured as donor cells. After 2 approximately 3 passages, the growth status, cell cycle, immunophenotype and morphology of DMSC were analyzed. Hematopoietic cells were plated onto a feeder layer formed by DMSC, cell count and CFU-GM yields were observed dynamically. Female mice received 5 Gy (137)Cs radiation were injected with DMSC cultured for 2 - 3 passages via tail vein. Cell count and CFU-GM yields of the bone marrow were observed regularly. Pathological study of the liver, spleen and bone marrow was done to evaluate hematopoiesis recovery.

RESULTSMurine DMSC are adherent cells with a morphology of fibroblastoid and spindle and multiangle in shape. Immunophenotypes showed that CD(45), CD(34), HL-DR positive DMSC were 1 - 3%, CD(44) and CD(13) positive DMSC 75 approximately 95%. Cell cycle assay demonstrated 83% of DMSC being G(0)/G(1) phase. In vitro, the total cell count and CFU-GM yields in the experimental group were higher than those of the long-term culture bone marrow cells by the third week. The DMSC can sufficiently support the proliferation and differentiation of hematopoietic cells for seven weeks. In vivo, peripheral granulocytic count, cells in the bone marrow of one femoral bone and CFU-GM by the third week in the experimental group were much higher than those of controls. Genetic assay of the murine blood demonstrated Y chromosome.

CONCLUSIONThe DMSC have characteristics of stem cells. DMSC sped up hematopoiesis recovery of irradiated mice. DMSC as a feeder layer can support proliferation and differentiation of hematopoietic cells.

Animals ; Bone Marrow Transplantation ; Female ; Hematopoiesis ; Immunophenotyping ; Male ; Mesoderm ; cytology ; Mice ; Mice, Inbred BALB C ; Skin ; cytology ; Stem Cell Transplantation ; Stem Cells ; physiology

It has recently been reported that bone marrow-derived mesenchymal stem cells (MSCs), which are systemically administrated to different species, undergo site-specific differentiation. This suggests that the tissue specific cells may cause or promote the differentiation of the MSCs toward their cell type via a cell-to-cell interaction that is mediated not only by hormones and cytokines, but also by direct cell-to-cell contact. In this study, in order to assess the possible synergistic interactions for osteogenesis between the two types of cells, the MSCs derived from rabbit bone marrow were co-cultured with rat calvarial osteoblasts in direct cell-to-cell contact in a control medium (CM) and in an osteogenic medium (OM). The cell number, alkaline phosphatase activity, and amount of calcium deposition were assayed in the cultures of MSCs, osteoblasts, and co-cultures of them in either OM or CM for up to 40 days. The cell numbers and the alkaline phosphatase activities in the co-culture were somewhere in between those of the osteoblast cultures and the MSC cultures. The amounts of deposited calcium were lower in the co-culture compared to those of the other cultures. This suggests that there are little synergistic interactions during osteogenesis in vitro between the rat osteoblasts and rabbit MSCs.
Alkaline Phosphatase/metabolism ; Animals ; Calcification, Physiologic ; *Cell Communication ; Cell Count ; Cell Differentiation ; Cell Division ; Female ; Mesoderm/*cytology ; Osteoblasts/*physiology ; *Osteogenesis ; Rabbits ; Stem Cells/*physiology

Mesenchymal stem cells possess the ability to differentiate into osteoblasts, chondroblasts, lipoblasts, myoblasts and so on, which can be used in the formation of hematopoietic microenvironment, tissue repairing and gene therapy. Growth factors such as TGF-beta, IGF-I, BMP and FGF can influence on the differentiation of MSC and they cooperate with each other. MSCs support hematopoiesis by secreting cytokines including G-CSF, SCF, LIF, M-CSF, IL-6, IL-11 and are related to some diseases. MSC would demonstrate important effect on gene engineering.
Animals ; Bone Morphogenetic Proteins ; physiology ; Cytokines ; physiology ; Fibroblast Growth Factors ; physiology ; Genetic Engineering ; Humans ; Mesoderm ; cytology ; Multiple Sclerosis ; etiology ; Osteoporosis ; etiology ; Stem Cells ; physiology ; Transforming Growth Factor beta ; physiology

The present study investigated the effects of transforming growth factor (TGF)-beta on retinal pigment epithelial (RPE) transformation in a simplified model and also whether or not TGF-beta exhibits similar proliferation effects on transformed RPE cells that it has on primary RPE cells. Furthermore, we examined the cell proliferation effects of RPE-conditioned medium (CM). A vertical wound measuring 2 mm in diameter was made on primary RPE monolayers. The expression of alpha- smooth muscle actin (SMA) by the cells located at the wound edges was observed using a confocal microscope under immunofluorescent staining. Cell proliferation was measured by incorporating 3H-thymidine into DNA. The presence of alpha- SMA was observed in the cells within the wound after treatment with TGF-beta2, while negative expression was observed in control cells. TGF-betas inhibited the proliferation of the primary cultures of RPE cells in a dose-dependent manner, but the spindle-shaped late-passaged RPE cells were not inhibited by these growth factors. The medium conditioned by RPE cells stimulated the proliferation of subconjunctival fibroblasts and inhibited the proliferation of primary RPE cells, in a manner similar to TGF-beta. These findings demonstrate that TGF-beta-stimulated RPE cells may evoke proliferative vitreoretinopathy through mesenchymal transformation and cell proliferation.
Actins/analysis ; Animal ; Cell Division/drug effects ; Cells, Cultured ; Culture Media, Conditioned ; DNA/biosynthesis ; Mesoderm/*cytology ; Pigment Epithelium of Eye/*cytology ; Rabbits ; Swine ; Transforming Growth Factor beta/*physiology ; Vitreoretinopathy, Proliferative/etiology

PURPOSE: Down-regulation of E-cadherin is a hallmark of the epithelial-to-mesenchymal transition (EMT). EMT progression in cancer cells is associated with the loss of certain epithelial markers and the acquisition of a mesenchymal phenotype, as well as migratory activities. Cyclooxygenase-2 (COX-2) expression is associated with tumor invasion and metastasis in colon cancer. This study investigated the relationship between E-cadherin and COX-2 in colon cancer cells and human colon tumors. MATERIALS AND METHODS: Colon cancer cell lines and immunohistochemistry were used. RESULTS: E-cadherin expression was inversely related to the expressions of COX-2 and Snail in colon cancer cells. Ectopic expression of COX-2 or Snail reduced E-cadherin and induced a scattered, flattened phenotype with few intercellular contacts in colon cancer cells. Treatment of cancer cells with phorbol 12-myristate 13-acetate increased the expressions of COX-2 and Snail, decreased 15-hydroxyprostaglandin dehydrogenase expression, and increased the cells' motility. In addition, exposure to prostaglandin E2 increased Snail expression and cell motility, and decreased E-cadherin expression. Membranous E-cadherin expression was lower in adenomas and cancers than in the adjacent, non-neoplastic epithelium. In contrast, the expressions of Snail and COX-2 were higher in cancers than in normal tissues and adenomas. The expressions of COX-2 and Snail increased in areas with abnormal E-cadherin expression. Moreover, COX-2 expression was related to higher tumor stages and was significantly higher in nodal metastatic lesions than primary cancers. CONCLUSION: This study suggests that COX-2 may have a role in tumor metastasis via EMT.
Adult ; Aged ; Aged, 80 and over ; Blotting, Western ; Cadherins/genetics/metabolism ; Cell Differentiation/genetics/physiology ; Cell Line, Tumor ; Cell Movement/drug effects/genetics ; Colonic Neoplasms/*metabolism/*pathology ; Cyclooxygenase 2/genetics/metabolism/*physiology ; Dinoprostone/pharmacology ; Epithelial Cells/*cytology/metabolism ; Epithelium/*metabolism ; Female ; HT29 Cells ; Homeodomain Proteins/genetics/metabolism ; Humans ; Immunohistochemistry ; Male ; Mesoderm/*cytology/*metabolism ; Middle Aged ; Reverse Transcriptase Polymerase Chain Reaction ; Tetradecanoylphorbol Acetate/pharmacology ; Transcription Factors/genetics/metabolism