Synapses are inter-neuronal connections that are fundamental working units in neural networks. How synapses are molecularly constructed is a fascinating question, which attracted scientists' attention for many decades. Neuromuscular junction, a field pioneered by Te-Pei FENG and many others, has been an excellent model for studying synaptogenesis and paved the way for our understanding of the synapse formation in the central nervous system. Recent studies shed new light on the molecular mechanisms of central synapse formation by discovering a group of cell adhesion molecules exerting potent synaptogenic effects. This review will focus on those cell adhesion molecules which can induce central synapse formation when expressed in non-neuronal cells.
Cell Adhesion ; Cell Adhesion Molecules ; physiology ; Humans ; Neuromuscular Junction ; physiology ; Synapses ; physiology

OBJECTIVE: To investigate the effects of the Arg-Gly-Asp polypeptedes (RGD) peptides-modified porous tantalum surface on osteoblasts morphology and expressions of osteogenesis factors, and to evaluate RGD peptides promotes junctura ossium of tantalum-bone interface in vivo. METHODS: RGD peptides of different concentrations (1 g/L, 5 g/L, and 10 g/L) were loaded to porous tantalum slices with a diameter of 10 mm and a thickness of 3 mm by physical absorption. The 3rd generation of MG63 cells were co-cultured with tantalum and divided into 4 groups: Ta-cells (control) group, 1 g/L cells/Ta/RGD group, 5 g/L cells/Ta/RGD group, and 10 g/L cells/Ta/RGD group. Porous tantalum compo-sites and osteoblasts-tantalum interface were observed by scanning electron microscopy. The adhesion rate of osteoblasts was detected and immunocytochemistry was used to detect the expressions of filamentous actin (F-actin), osteocalcin (OC) and fibronectin (FN). RESULTS: The scanning electron microscope (SEM) revealed that osteoblasts distributed on the surface of porous tantalum and secreted extracellular matrix on outside and inner of micro-pores. The osteoblasts adhesion rate on porous tantalum modified with RGD was higher than that in the unmodified porous tantalum at the end of 24, 48, and 72 hours. The best adhesion effect was got in 5 g/L cells/Ta/RGD group at hour 48 [(68.07±3.80) vs. (23.40±4.39), P<0.05]. The results of immunocytochemistry showed that the expressions intensity of F-actin, OC and FN in osteoblasts on porous tantalum modified groups with RGD were stronger than that in the unmodified groups, and the expressions of 5 g/L cells/Ta/RGD group were significantly higher than those in the 10 g/L group and 1 g/L group [OC: (18.08±0.08) vs. (15.14±0.19), P<0.05; (18.08±0.08) vs. (14.04±0.61), P<0.05. FN: (24.60±0.98) vs. (15.90±0.53), P<0.05; (24.60±0.98) vs. (15.30±0.42), P<0.05. F-actin: (29.20±1.31) vs. (24.50±1.51), P<0.05; (29.20±1.31) vs. (16.92±0.40), P<0.05]. Correspondingly F-actin in osteoblasts was showed in longitudinal arrangement, and the expressions intensity was stronger than those OC and FN. CONCLUSION The RGD peptides is beneficial to enhance adhesion of osteoblast, spreading and reorganization of cytoskeleton on porous tantalum surface and improve the interface morphology, further promoting osteoblasts-tantalum conjunctive interface osseointegration.
Cell Adhesion ; Oligopeptides ; Osteoblasts/physiology* ; Osteogenesis ; Tantalum

Synaptic cell adhesion molecules (CAMs) are a type of membrane surface glycoproteins that mediate the structural and functional interactions between pre- and post-synaptic sites. Synaptic CAMs dynamically regulate synaptic activity and plasticity, and their expression and function are modulated by environmental factors. Synaptic CAMs are also important effector molecules of stress response, and mediate the adverse impact of stress on cognition and emotion. In this review, we will summarize the recent progress on the role of synaptic CAMs in stress, and aim to provide insight into the molecular mechanisms and drug development of stress-related disorders.
Cell Adhesion ; Cell Adhesion Molecules ; physiology ; Humans ; Neuronal Plasticity ; Stress, Physiological ; Stress, Psychological ; Synapses

The adhesion of leukocytes to substrate is an important biomedical engineering problem and has drawn extensive research. In this study, we have proposed a compound drop model to simulate a leukocyte with a nucleus adhered to the surface of a blood vessel under steady shear flow. A two-dimensional computational fluid dynamics (CFD) is conducted to determine the local distribution of pressure on the surface of the adherent model cell. By introducing the parameter of deformation index (DI), we have investigated the deformation of the model cell and it's nucleus under controlled conditions. Our numerical results show that: (1) the model cell is capable of deformation with the increase of initial contact angle, capillary number, and Reynolds number, and that the cytoplasm is more deformable while the nucleus is more capable of resisting external imposed shear flow; (2) the model cell is not able to deform infinitely with the increase of external shear flow because the deformation index reaches a maximum; (3) pressure distribution confirms that there exists a region downstream of the cell, which produces high pressure to retard continuous deformation and provide a positive lift force on the cell. Our results of nucleus deformation may help to develop a better understanding of how leukocytes transduce external mechanical signal like shear stress into nucleus.
Biomechanical Phenomena ; Blood Vessels ; cytology ; physiology ; Cell Adhesion ; physiology ; Cell Nucleus ; physiology ; Leukocytes ; physiology ; Models, Cardiovascular ; Numerical Analysis, Computer-Assisted

Fetal wound healing has drawn the attention of many researchers from diverse background and specialties. Fetal wound healing is unique and differs from postnatal healing in that fetal skin wounds heal rapidly without scar formation. If the mechanism underlying such phenomenon can be elucidated, it will be serve as a significant milestone in the study of wound healing. Furthermore, the implications for therapeutic applications in wound management and in diseases where scarring is the basic pathogenetic mechanism would be immense. Rather than to list the results and conflicting data of numerous studies, this article hopes to provide a general overview of the recent developments.
Animal ; Cell Adhesion Molecules/physiology ; Collagen/physiology ; Extracellular Matrix/physiology ; Fetus/*physiology ; Growth Substances/physiology ; Human ; *Wound Healing

OBJECTIVETo study mechanisms of reduction of the malignant activities of human naso-pharyngeal carcinoma cell CNE-2L2 induced by ectopic expression of BCSC-1 gene.

METHODSDNA was stained with propidium iodide and assayed upon a flow cytometer. Chromosomes were stained with Hoechest 33258. Adhesion of CNE-2L2 cells was detected by cell aggregation test. Protein expression on CNE-2L2 cells was examined by Western blot.

RESULTSCell cycle analysis showed that the percentage of CNE-2L2 cells was 55.1%, 43.4%, and 39.4% in G0/G1 phase, 25.2%, 28.7%, and 30.9% in S phase, and 19.7%, 27.9%, and 29.7% in G2/M phase for the cell with ectopic expression of BCSC-1 gene, wild type cell (W cells), and the cell transduced with the mock (M cell). Many mitotic cells were found in W cells and M cells. In contrast, almost no mitotic cell was observed in the cells with ectopic expression of BCSC-1 gene. Ectopic BCSC-1 expression resulted in cell aggregation, enhanced expression of E-cadherin, cx-catenin, and p53.

CONCLUSIONSEctopic BCSC-1 expression causes enhancement of adhesion of CNE-2L2 cells associated with enhanced expression of E-cadherin and alpha-catenin, arrest of cell in G1 phase, which may be associated with enhanced expression of p53. These alteration may play a role in the reduction of malignant activities of the cells with ectopic expression of BCSC-1 gene.

Cell Adhesion ; Cell Cycle ; physiology ; Cell Line, Tumor ; Humans ; Nasopharyngeal Neoplasms ; Neoplasm Proteins ; biosynthesis ; genetics

The process of human embryo implantation is mediated not only by evolutionarily conserved mechanisms, but also by a mechanism unique to humans. Evidence suggests that the cell adhesion molecules, L-selectin and trophinin, play a unique role in human embryo implantation. Here, we describe the dual roles of mucin carbohydrate ligand for L-selectin and trophinin protein and of the trophinin-associated proteins bystin and tastin. We then describe trophinin-mediated signal transduction in trophectoderm cells and endometrial epithelial cells. This review also covers cadherin and integrin in human embryo implantation.
Cadherins ; physiology ; Cell Adhesion Molecules ; physiology ; Embryo Implantation ; Epithelial Cells ; metabolism ; Humans ; Integrins ; physiology ; L-Selectin ; physiology ; Signal Transduction

OBJECTIVETo compared the difference in contact guidance activity among microgroove surfaces with different sizes of human gingival fibroblast (HGF), with the hope of providing basis for size selection of microgroove for transmucosal part of dental implant.

METHODSBasing on the size of HGF, microgroove titanium surfaces were fabricated by photolithography with parallel grooves: 15, 30 or 60 µm in width and 5 or 10 µm in depth. The groups that used different microgroove surfaces were denoted as T15/5, T15/10, T30/5, T30/10, T60/5, and T60/10. Group T0 (the control meanwhile was a sputter of titanium on a simple planar silicon substrate). The morphology that HGF arranged along the groove was analyzed by immunofluorescence staining. Difference in contact guidance activity was quantitatively compared basing on the consistency of nucleus arrangement and deformation ratio.

RESULTSMicrogroove groups had significantly higher consistency of nucleus arrangement and deformation ratio compared to the control group, with T60/10 had the highest consistency of 0.937±0.024, and T15/5 had the lowest consistency of 0.660±0.016 and T60/10 had the highest deformation ratio of 3.555±0.205, and T15/5 had the lowest deformation ratio of 1.819±0.011.

CONCLUSIONSMicrogroove surfaces of all the different sizes show contact guidance activity on HGF, and the contact guidance activity increases with the increase of width and depth.

Cell Adhesion ; physiology ; Dental Implants ; Fibroblasts ; cytology ; physiology ; Gingiva ; cytology ; Humans ; Surface Properties ; Titanium

This study was done for investigating the frequency and proliferative feature of mesenchymal stem/progenitor cells (MSPC) in human umbilical cord blood (CB) and for searching a new seed cell for tissue engineering. Mononuclear cells was separated by Ficoll-Hypaque from cord blood and suspended in DMEM culture medium supplemented by 2% fetal bovine serum. The adherent CB cells were cultured and expanded at same medium. The results showed that the frequency of CB-MSPC was 0.5 x 10(-6) [(0.2 - 0.8) x 10(-6)]. The CB-MSPC showed a fibroblast-like morphology and retained their morphological feature at least after 20 sub-passages, and could extensively be expanded by about 1.3 x 10(7) times as much. The conclusion is that low serum DMEM culture could maintain the proliferation and differentiation potential of CB-MSPC. CB-MSPC might be a favorable seed cell for tissue engineering and regeneration.
Cell Adhesion ; Cell Division ; Fetal Blood ; cytology ; Humans ; Mesenchymal Stromal Cells ; physiology ; Tissue Engineering

OBJECTIVETo investigate the effect on adhesion and motion capbilities of adenoid cystic carcinoma (ACC), by detecting the expression of nerve growth factor (NGF), E-cadherin (E-cad) and S100A4 and the clinical significance in ACC tissues and analyzing the relationships between them with perineural invasion (PNI).

METHODSThe expression of NGF, E-cad and S100A4 in ACC was detected with the way of immunohistochemistry SP, and then analyzing the expression level of them in different pathological types and histological regions in statistical ways on the basis of their relation with clinical and pathological parameters.

RESULTSThe expression of NGF and S100A4 in PNI group [88% (23/26) and 77% (20/26)], was higher than that in NPNI group (8/16 and 7/16, P < 0.05), and a positive correlation between them was identified in PNI group (r = 0.316, P < 0.05). However the E-cad expression was lower in PNI group [31% (8/26), P < 0.05]. On the other hand it suggested a negative correlation with NGF (r = 0.385, P < 0.05) as well as that with S100A4 (r = -0.612, P = 0.000). The expression level of NGF in fasciculus [83% (25/30)] has significant deviation compared with it in distant tumor tissues [47% (14/30), P < 0.05].

CONCLUSIONSIn the PNI process of ACC, NGF plays important parts but not the only factor. It can increase the expression and activity of S100A4 but decrease E-cad expression through binding with its receptor. Thus, adhesion abilities of tumor cells was weakened and motional abilities was strengthen.

Cadherins ; biosynthesis ; Carcinoma, Adenoid Cystic ; pathology ; Cell Adhesion ; Cell Movement ; Humans ; Immunohistochemistry ; Nerve Growth Factor ; physiology