Actin cytoskeleton has been known to control and/or be associated with chondrogenesis. Staurosporine and cytochalasin D modulate actin cytoskeleton and affect chondrogenesis. However, the underlying mechanisms for actin dynamics regulation by these agents are not known well. In the present study, we investigate the effect of staurosporine and cytochalasin D on the actin dynamics as well as possible regulatory mechanisms of actin cytoskeleton modulation. Staurosporine and cytochalasin D have different effects on actin stress fibers in that staurosporine dissolved actin stress fibers while cytochalasin D disrupted them in both stress forming cells and stress fiber-formed cells. Increase in the G-/F-actin ratio either by dissolution or disruption of actin stress fiber is critical for the chondrogenic differentiation. Cytochalasin D reduced the phosphorylation of cofilin, whereas staurosporine showed little effect on cofilin phosphorylation. Either staurosporine or cytochalasin D had little effect on the phosphorylation of myosin light chain. These results suggest that staurosporine and cytochalasin D employ different mechanisms for the regulation of actin dynamics and provide evidence that removal of actin stress fibers is crucial for the chondrogenic differentiation.
Actin Cytoskeleton/*drug effects ; Actins/metabolism ; Animals ; Cell Differentiation/*drug effects ; Cells, Cultured ; Chickens ; Chondrogenesis/*drug effects ; Cytochalasin D/*pharmacology ; Mesoderm/cytology/drug effects ; Myosin Light Chains/metabolism ; Nucleic Acid Synthesis Inhibitors/*pharmacology ; Phosphorylation ; Staurosporine/*pharmacology ; Stress Fibers/drug effects

OBJECTIVE: To explore the expression and distribution of vimentin in different types of chronic rhinosinusitis and its significance. METHOD: There were four groups including control (10 samples), Eos CRSwNP (10 samples), non-Eos CRSwNP (12 samples) and CRSsNP (10 samples). The expression of vimentin in chronic rhinosinusitis were detected by immunohistochemistry technique. The double-immunofluorescence was used to detect the positive staining of both vimentin and E-cadherin, both of which were the marker of epithelial cells. RESULT: The positive staining of vimentin were observed both in epithelium and lamina propria. The expression of vimentin were found in myofibroblast, endothelium and other mesenchymal cells. The vimentin positive cells in epithelium were epithelial cells but not mesenchymal cells, as they also expressed E-cadherin. CONCLUSION The vimentin positive staining cells distribute in lamina propria and epithelium of both normal nasal mucosa and chronic rhinosinusitis. The positive staining epithelial cells may generate from epithelial-mesenchymal transition. So the vimentin may play an important role in the development of chronic rhinosinusitis.
Adult ; Antigens, CD ; Cadherins ; metabolism ; Chronic Disease ; Epithelial Cells ; metabolism ; Female ; Humans ; Male ; Mesoderm ; cytology ; metabolism ; Middle Aged ; Nasal Mucosa ; metabolism ; Sinusitis ; metabolism ; pathology ; Vimentin ; metabolism ; Young Adult

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

This study was done to evaluate the stemness of human mesenchymal stem cells (hMSCs) derived from placenta according to the development stage and to compare the results to those from adult bone marrow (BM). Based on the source of hMSCs, three groups were defined: group I included term placentas, group II included first-trimester placentas, and group III included adult BM samples. The stemness was evaluated by the proliferation capacity, immunophenotypic expression, mesoderm differentiation, expression of pluripotency markers including telomerase activity. The cumulative population doubling, indicating the proliferation capacity, was significantly higher in group II (P<0.001, 31.7+/-5.8 vs. 15.7+/-6.2 with group I, 9.2+/-4.9 with group III). The pattern of immunophenotypic expression and mesoderm differentiation into adipocytes and osteocytes were similar in all three groups. The expression of pluripotency markers including ALP, SSEA-4, TRA-1-60, TRA-1-81, Oct-4, and telomerase were strongly positive in group II, but very faint positive in the other groups. In conclusions, hMSCs from placentas have different characteristics according to their developmental stage and express mesenchymal stemness potentials similar to those from adult human BMs.
Antigens, Surface/metabolism ; Bone Marrow Cells/*cytology/metabolism ; Cell Proliferation ; Female ; Humans ; Immunophenotyping ; Mesenchymal Stem Cells/*cytology/metabolism ; Mesoderm/cytology ; Octamer Transcription Factor-3/metabolism ; Placenta/*cytology/growth & development ; Pregnancy ; Pregnancy Trimester, First ; Proteoglycans/metabolism ; Stage-Specific Embryonic Antigens/metabolism ; Telomerase/metabolism

Recently, reactive oxygen species (ROS) have been studied as a regulator of differentiation into specific cell types in embryonic stem cells (ESCs). However, ROS role in human ESCs (hESCs) is unknown because mouse ESCs have been used mainly for most studies. Herein we suggest that ROS generation may play a critical role in differentiation of hESCs; ROS enhances differentiation of hESCs into bi-potent mesendodermal cell lineage via ROS-involved signaling pathways. In ROS-inducing conditions, expression of pluripotency markers (Oct4, Tra 1-60, Nanog, and Sox2) of hESCs was decreased, while expression of mesodermal and endodermal markers was increased. Moreover, these differentiation events of hESCs in ROS-inducing conditions were decreased by free radical scavenger treatment. hESC-derived embryoid bodies (EBs) also showed similar differentiation patterns by ROS induction. In ROS-related signaling pathway, some of the MAPKs family members in hESCs were also affected by ROS induction. p38 MAPK and AKT (protein kinases B, PKB) were inactivated significantly by buthionine sulfoximine (BSO) treatment. JNK and ERK phosphorylation levels were increased at early time of BSO treatment but not at late time point. Moreover, MAPKs family-specific inhibitors could prevent the mesendodermal differentiation of hESCs by ROS induction. Our results demonstrate that stemness and differentiation of hESCs can be regulated by environmental factors such as ROS.
Biological Markers/metabolism ; Cell Differentiation/*drug effects ; Cell Line ; Cell Lineage/*drug effects ; Cells, Cultured ; Down-Regulation/drug effects ; Embryo, Mammalian/cytology/drug effects/metabolism ; Embryonic Stem Cells/*cytology/*drug effects/enzymology ; Endoderm/*cytology/drug effects ; Enzyme Activation/drug effects ; Free Radical Scavengers/pharmacology ; Humans ; Mesoderm/*cytology/drug effects ; Mitogen-Activated Protein Kinases/metabolism ; Pluripotent Stem Cells/cytology/metabolism ; Reactive Oxygen Species/metabolism/*pharmacology ; Up-Regulation/drug effects

OBJECTIVE: To construct the cell model of epithelium to mesenchymal transition of proximal tubule cells induced by high glucose and to determine the expression of Smad anchor for receptor activation (SARA). METHODS: Protein expression of vimentin, Zona occludens-1(ZO-1), and SARA was determined by Western blot, and their mRNA expressions were detected by Real-time PCR. RESULTS: After stimulation by 30 mmol/L D-glucose, the protein and mRNA expression levels of vimentin in HK-2 cells increased in a time-dependent manner while the expression of ZO-1 was reduced significantly, especially at 48 h. Meanwhile, SARA was also decreased in a time-dependent manner. CONCLUSION High glucose can induce renal epithelium to mesenchymal transition, and SARA may be involved in this process as a protector.
Cell Differentiation ; Cells, Cultured ; Epithelial Cells ; cytology ; Glucose ; pharmacology ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Kidney Tubules, Proximal ; cytology ; metabolism ; Membrane Proteins ; metabolism ; Mesoderm ; cytology ; Phosphoproteins ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Serine Endopeptidases ; genetics ; metabolism ; Signal Transduction ; Transforming Growth Factor beta1 ; pharmacology ; Vimentin ; metabolism ; Zonula Occludens-1 Protein

OBJECTIVE: To investigate the role of phosphorylation of glycogen synthase kinase-3beta (GSK-3beta) inducing epithelial mesenchymal transition in human peritoneal mesothelial cells (HPMC). METHODS: Primary HPMC was harvested from human omental tissue and maintained under defined in vitro conditions. The expression of p-GSK-3beta and total GSK-3beta in HMPC was detected by Western blot after incubation with different concentrations (0, 5, 10, 20, and 40 mmol/L)of LiCl at different time points (0, 1, 3, 6, and 12 h). The protein expression of E-cadherin and alpha-SMA was also examined after treatment with 20 mmol/L LiCl according to different time courses. The intracellular distribution and expression of alpha-SMA were determined by indirect immunofluorescence. RESULTS: LiCl stimulated phosphorylation of GSK-3beta and the effect was time-dependent and concentration-dependent to limited extent (P<0.05). The expression of alpha-SMA increased (P<0.05) and the expression of E-cadherin decreased significantly (P<0.05) after 24 h stimulation by 20 mmol/L LiCl. The indirect immunoflurescence showed that the expression of alpha-SMA in HPMC increased significantly after 24 h incubation with 20 mmol/L LiCl. CONCLUSION The phosphorylation of GSK-3beta leads HMPC to epithelial mesenchymal transition and provides new clue for the treatment of peritoneal fibrosis.
Actins ; metabolism ; Cadherins ; metabolism ; Epithelial Cells ; cytology ; drug effects ; Epithelial-Mesenchymal Transition ; drug effects ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Humans ; Lithium Chloride ; pharmacology ; Mesoderm ; cytology ; drug effects ; Peritoneum ; cytology ; Phosphorylation

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

OBJECTIVETo investigate the role of connective tissue growth factor (CTGF) in epithelial mesenchymal transition of HK-2 cells in vitro.

METHODSHK-2 cells were randomly divided into two groups: (1) control group including cells cultured in DMEM medium supplemented with 10% fetal bovine serum only; and (2) experimental group including cells cultured in DMEM medium supplemented with 10% fetal bovine serum and recombinant CTGF at a final concentration of 5 microg/L. The cells were collected at 72 h time points. Direct immunofluorescence staining and immunohistochemistry were used to evaluate the E-cadherin, Vimentin, alpha-SMA and ERK2 in cells. Western-blotting was used to detect the E-cadherin, Vimentin and ERK2 protein expression. Boyden Chamber was used to detect the migration of tubular endothelium at 1 d, 3 d and 5 d.

RESULTSThere were less E-cadherin but more Vimentin expressed in cells of the experimental group. The presence of alpha-SMA was detected at 48 h with peak at 72 h in the cells of the experimental group. On the first day, the cellular migration in the two groups showed no difference. However, after 3 days, the transformed cells migrated surpassed the control group with peak at the 5th day [(45.0+/-1.1):(14.0+/-1.2), P<0.05)].

CONCLUSIONConnective tissue growth factor induces mesenchymal transformation of HK-2 cells, in which the ERK2 signaling pathway may play an important role.

Actins ; metabolism ; Cadherins ; metabolism ; Cell Line ; Cell Movement ; drug effects ; Connective Tissue Growth Factor ; pharmacology ; Epithelial Cells ; cytology ; metabolism ; Epithelial-Mesenchymal Transition ; drug effects ; Humans ; Kidney Tubules, Proximal ; cytology ; Mesoderm ; cytology ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Random Allocation ; Signal Transduction ; Vimentin ; metabolism

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