Progress in research on connexin 43 in oral squamous cell carcinoma / 口腔疾病防治

@#Cell gap junctions are a universal form of cellular connection in animal tissue that mediate the exchange of information, energy and material between adjacent cells. Clinical studies have demonstrated that the abnormal expression of the connexin 43 （Cx43） gene is closely associated with carcinogenesis and tumor progression. The present study reviewed relevant studies concerning the association between abnormal expression of Cx43 and oral squamous cell carcinoma as well as communication abnormalities of cell gap junctions.

Effect of magnesium ion on human osteoblast activity

Magnesium, a promising biodegradable metal, has been reported in several studies to increase bone formation. Although there is some information regarding the concentrations of magnesium ions that affect bone remodeling at a cellular level, little is known about the effect of magnesium ions on cell gap junctions. Therefore, this study aimed to systematically investigate the effects of different concentrations of magnesium on bone cells, and further evaluate its effect on gap junctions of osteoblasts. Cultures of normal human osteoblasts were treated with magnesium ions at concentrations of 1, 2 and 3 mM, for 24, 48 and 72 h. The effects of magnesium ions on viability and function of normal human osteoblasts and on gap junction intercellular communication (GJIC) in osteoblasts were investigated. Magnesium ions induced significant (P<0.05) increases in cell viability, alkaline phosphate activity and osteocalcin levels of human osteoblasts. These stimulatory actions were positively associated with the concentration of magnesium and the time of exposure. Furthermore, the GJIC of osteoblasts was significantly promoted by magnesium ions. In conclusion, this study demonstrated that magnesium ions induced the activity of osteoblasts by enhancing GJIC between cells, and influenced bone formation. These findings may contribute to a better understanding of the influence of magnesium on bone remodeling and to the advance of its application in clinical practice.

Neuropeptide Y, substance P, and human bone morphogenetic protein 2 stimulate human osteoblast osteogenic activity by enhancing gap junction intercellular communication

Bone homeostasis seems to be controlled by delicate and subtle “cross talk” between the nervous system and “osteo-neuromediators” that control bone remodeling. The purpose of this study was to evaluate the effect of interactions between neuropeptides and human bone morphogenetic protein 2 (hBMP2) on human osteoblasts. We also investigated the effects of neuropeptides and hBMP2 on gap junction intercellular communication (GJIC). Osteoblasts were treated with neuropeptide Y (NPY), substance P (SP), or hBMP2 at three concentrations. At various intervals after treatment, cell viability was measured by the MTT assay. In addition, cellular alkaline phosphatase (ALP) activity and osteocalcin were determined by colorimetric assay and radioimmunoassay, respectively. The effects of NPY, SP and hBMP on GJIC were determined by laser scanning confocal microscopy. The viability of cells treated with neuropeptides and hBMP2 increased significantly in a time-dependent manner, but was inversely associated with the concentration of the treatments. ALP activity and osteocalcin were both reduced in osteoblasts exposed to the combination of neuropeptides and hBMP2. The GJIC of osteoblasts was significantly increased by the neuropeptides and hBMP2. These results suggest that osteoblast activity is increased by neuropeptides and hBMP2 through increased GJIC. Identification of the GJIC-mediated signal transduction capable of modulating the cellular activities of bone cells represents a novel approach to studying the biology of skeletal innervation.

Effects of different types of Helicobacter pylori on the gap junction intercellular communication in GES-1 cells / 中南大学学报(医学版)

Objective To determine the effect of different types of Helicobacter pylori(H, pylori) on the gap junction intercellular communication (GJIC) in GES-1 cells, and investigate the types of H. pylorirelated to the dysfunction of GJIC. Methods Different types of H. pylori clinical strains were isolated and cultured, including the East Asian CagA-positive H. pylori( East Asian CagA +H. pylorl), Western CagA-positive H. pylori( Western CagA +H. pylori), and the CagA-negative H. pylori (CagA-H. pylori). We co-cultured these H. pyloristrains with GES-1 cells for 24 and 48h, respectively. The control group was cultured without any H. pylorifor 24 and 48 h. Change of the GJIC function in GES-1 cells was detected by the scrape-loading dye transfer (SLDT) technique. The cell proliferation of each group was examined by the methyl thiazolyl tetrazolium bromide (MTT) assay. Results The control group showed better GJIC function in the GES-1 cells, and the fluorescent dye migrated 4 - 5 rows to the adjacent cells at 24 and 48 h. Compared with the control group, the GJIC function of GES-1 cells in the CagA - H. pylori group decreased and the fluorescent dye migrated 3 rows to the adjacent cells. Compared with the control group and the CagA- H. pylori group, the GJIC function of GES-1 cells in the Western CagA + H. pylori group decreased and the fluorescent dye migrated 1 - 2 rows to the adjacent cells. The East Asian CagA * H. pylori group showed no GJIC function or weak GJIC function, and most of the fluorescent dye was confined to the area of scratched single row cells and only a few migrated 1 -2 rows to the adjacent cells. Difference in the cell proliferation between the CagA - H. pylorigroup and the control group was not significant. The cell proliferation of the Western CagA + H. pylori group and the East Asian CagA + H. pylori group at bacterium-to-cell ratio of 100:1 and 200:1 was higher than that of the control group. The cell proliferation of the East Asian CagA +H. pylori group at bacterium-to-cell ratio of 400:1 was significantly lower than that of the control group at 48 h. Conclusion H. pylorican inhibit the GJIC function in GES-1 cells, which may be associated with CagA +H. pylori, especially with East Asian CagA +H. pylori. The effect of H. pylori on the proliferation of GES-I cells is related to virulence factor CagA.

Expression of connexin 43 gene and the gap junction intercellular communication among cultured unstable detrusor cells / 第三军医大学学报

Objective To investigate the expression changes of connexin 43 (Cx43) gene and the functional changes of the gap junction intercellular communication (GJIC) among cultured unstable detrusor cells and their roles in the development of detrusor instability (DI). Methods Forty healthy female Wistar rats were divided into two groups: DI group and normal control group. RT-PCR and Western blot techniques were employed to detect the expression of Cx 43 mRNA and protein in the cultured detrusor cells. Scrape loading dye transfer (SLDT) technique was used to monitor the GJIC among cultured detrusor cells. Results The expression of Cx43 mRNA and protein in DI group was much higher than that in normal control group (P

Effects of ATRA on interacellular communication function and connexin 43 expressions in acute leukemia bone marrow stremal cells / 解放军医学杂志

Objective To observe the effects of all-tram retinoic acid(ATRA)on intercellular communication function and connexin 43 expression in acute leukemia bone marrow stromal cells(ALBMSCs).Methods ALBMSCs were cultured in vitro,and the ATRA(1?10~(-5)mol/L)was added after serial subcultivation.The expression level of Cx43 was detected by immunochemistry and flow cytometry, and the gap junction intercellular communication(GJIC)was examined by using cell scarification with dye transfer(CSDT)technique.Re- sults Before and after addition of ATRA,the positive rates of Cx43 expression as detected by immunochemistry in ALBMSCs were(47.2?2.04)% and(54.5?5.86)%,respectively.The positive rates of Cx43 expression in ALBMSCs as detected by flow cytometry before and after the addition of ATRA were(38.75?23.95)% and(49.5?5.46)%,respectively.The expression of Cx43 in ALBMSCs after adding ATRA was significantly higher than that before the addition of ATRA(P

UP-REGULATION OF GAP JUNCTION INTERCELLULAR COMMUNICATION BY TEA POLYPHENOLS IN HUMAN METASTATIE LUNG TUMOR CELL LINE / 解放军医学杂志

The anti proliferation effects of four different concentrations of tea polyphenols on PG cell lines were determined with MTT assay. Laser scanning confocal mircroscopy and flow cytometry techniques were used to determine the changes in intracellular calcium concentration, GJIC, Cx43 expression, and cell cycle distribution after treatment with tea polyphenols. The results showed that four different concentrations dose dependently inhibited the proliferation of PG cell lines. It caused a decline in the proportion of cells in S and G2/M phase, blocked the cell cycle progression in G0/G1 phase, and reduced the proliferation index of PG cell lines. Compared with control group, intracellular calcium concentration, GJIC and Cx43 expression were gradually increased ascended with an increase in tea polyphenols concentration. The results suggested that tea polyphenol could inhibit growth of PG cell lines. The mechanism of anti tumor is associated with an up regulation of GJIC of PG cell line.

EFFECT OF 1?,25-DIHYDROXYVITAMIN D_3 ON CYTOSKELETON,GAP JUNCTION INTERCELLULAR COMMUNICATION AND [Ca~(2+)]_i OF OSTEOBLASTS / 营养学报

Objective To study the effect of 1?,25-dihydroxyvitamin D3[1,25-(OH)2D3] on cytoskeleton,gap junction intercellular communication (GJIC) and intracellular Ca2+ ([Ca2+]i) in osteoblasts (OB) in vitro. Method OB were isolated from calvaria bone. After 20 min and after 24 h treated by 1,25-(OH)2 VD3 (0,10-9,10-8,10-7 mol/L),[Ca2+]i was evaluated. F-actin and GJIC were observed after 24 and 48 h incubation later. Results Compared with the control group,[Ca2+]i in all 1,25-(OH)2 D3 groups was increased significantly at 20 min. [Ca2+]i in 10-9 mol/L 1,25-(OH)2D3 group was the lowest at 24 h after treatment. OB in 10-8 and 10-7 mol/L 1,25-(OH)2D3 groups were flat,and stress fibers were formed. The expression of F-actin in control group and 10-9 mol/L 1,25-(OH)2D3 group was reduced at 48 h after treatment. Compared with the control group,GJIC was weakened very significantly after treated with 10-9 mol/L 1,25-(OH)2D3 at 48 h,but enhanced very significantly in the group with 10-8 and 10-7 mol/L. Conclusion Higher dosage of 1,25-(OH)2D3 can maintain the morphology of OB and stimulate the communication among OB,but lower dosage can inhibit it.