Gap junction (GJ) has been indicated to have an intimate correlation with adhesion junction. However, the direct interaction between them partially remains elusive. In the current study, we aimed to elucidate the role of N-cadherin, one of the core components in adhesion junction, in mediating connexin 43, one of the functional constituents in gap junction, via transforming growth factor-β1(TGF-β1) induction in osteoblasts. We first elucidated the expressions of N-cadherin induced by TGF-β1 and also confirmed the upregulation of Cx43, and the enhancement of functional gap junctional intercellular communication (GJIC) triggered by TGF-β1 in both primary osteoblasts and MC3T3 cell line. Colocalization analysis and Co-IP experimentation showed that N-cadherin interacts with Cx43 at the site of cell-cell contact. Knockdown of N-cadherin by siRNA interference decreased the Cx43 expression and abolished the promoting effect of TGF-β1 on Cx43. Functional GJICs in living primary osteoblasts and MC3T3 cell line were also reduced. TGF-β1-induced increase in N-cadherin and Cx43 was via Smad3 activation, whereas knockdown of Smad3 signaling by using siRNA decreased the expressions of both N-cadherin and Cx43. Overall, these data indicate the direct interactions between N-cadherin and Cx43, and reveal the intervention of adhesion junction in functional gap junction in living osteoblasts.
Cadherins ; Cell Communication ; Connexin 43 ; Osteoblasts ; Transforming Growth Factor beta1

Atrial Fibrillation ; metabolism ; Connexin 43 ; metabolism ; Humans ; Oxidative Stress

OBJECTIVETo investigate the expressions of Cx26, Cx32 and Cx43 in prostate cancer (PCa) and benign prostatic hyperplasia (BPH) and their roles in the development and progression of PCa in order to provide some novel evidence for the diagnosis and treatment of PCa.

METHODSWe determined the expressions of Cx26, Cx32 and Cx43 in the paraffin samples from 31 cases of PCa and 23 cases of BPH by SABC immunohistochemical staining, and analyzed the relationship of their expressions with the clinical and pathological parameters of PCa and BPH using the semiquantitative method.

RESULTSThe positive expressions of Cx26 in BPH and PCa were 82.6% and 74.2%, respectively (chi2 = 0.541, P > 0.05), those of Cx32 were 78.3% and 61.3% (chi2 = 1.763, P > 0.05), and those of Cx43 were 87.0% and 38.7% (chi2 = 12.730, P < 0.01). The staining intensities of Cx26 and Cx43 were negatively correlated with the malignant phenotype of PCa (rCx26 = -0.476, P < 0.01; rCx43 = -0.484, P < 0.01), but not the expression of Cx32 (r = -0.242, P > 0.05). The three Cxs exhibited no correlation with the age and serum PSA level of the patients (P > 0.05), nor among their expressions (P > 0.05).

CONCLUSIONCx26, Cx32 and Cx43 are expressed in different degrees in BPH and PCa tissues. Cx43 plays a role in the occurrence and progression of PCa, and may serve as a new marker of PCa besides PSA as well as a new target in the biotherapy of PCa. Cx26 may be partially involved in the progression of PCa, but its mechanisms need to be further studied.

Aged ; Aged, 80 and over ; Connexin 26 ; Connexin 43 ; metabolism ; Connexins ; metabolism ; Humans ; Male ; Prostate ; metabolism ; Prostatic Neoplasms ; metabolism

PURPOSE: Selective introduction of genes conferring chemosensitivity into proliferating tumor cells may be used to treat cancer. We first investigated the bystander effect of retrovirus-mediated gene transfer of herpes simplex virus thymidine kinase(HSV-TK) gene to murine neuroblstoma cell line(neuro-2a) in vitro and in vivo. Second, we examined the mechanism and its enhancement of the bystander effect in murine neuroblastoma. METHODS: To investigate the bystander effect, we studied tumor growth and survival time after HSV-TK/ganciclovir(GCV) treatment in a syngenic A/J mouse neuroblastoma model by mixing various ratios of HSV-TK-expressing neuro-2a cells with wild type neuro-2a cells followed by GCV treatment. To investigate the mechanism of the bystander effect in murine neuroblastoma, immunohistochemistry using connexin 43, CD4 and CD8-specific monoclonal antibodies was analyzed. We studied whether IL-2-secreting neuro-2a cells(neuro-2a/IL-2) would potentiate the bystander effect. RESULTS: A strong bystander effect was observed in vitro and in vivo. The bystander effect in murine neuroblastoma was dependent on the immune response rather than connexin-mediated gap junction. Neuro-2a/IL-2 treatment enhanced the bystander effect in the HSV-TK/GCV system in murine neuroblastoma model. CONCLUSION: We conclude that the bystander effect in murine neuroblastoma depends on immune response and is enhanced by neuro-2a/IL-2.
Animals ; Antibodies, Monoclonal ; Bystander Effect* ; Connexin 43 ; Gap Junctions ; Genetic Therapy* ; Immunohistochemistry ; Mice ; Neuroblastoma* ; Simplexvirus ; Thymidine

Gap junctions (GJ), as a special membrane structure between adjacent cells, are composed of connexins (Cx) and regulate the proliferation and differentiation of cells. Studies show that gap junctional intercellular communication is weakened or lost in most tumor cells and this abnormality is often accompanied by changed expression of Cxs. Cx43 is a major connexin in the testis tissue. This review focuses on the latest progress in the studies of Cx43 in testicular tumors.
Animals ; Cell Communication ; Cell Differentiation ; Connexin 43 ; metabolism ; Gap Junctions ; metabolism ; Male ; Testicular Neoplasms ; metabolism

Objective To study the effect of overwork stress response on the expression of connexin 43（Cx43） and connexin 45（Cx45） in cardiomyocytes and on cardiac function. Methods The experimental animals were divided into control group, overworked 1-month group and overworked 2-month group. A overworked rat model was established by forcing swimming of overworked group. The expressions of Cx43 and Cx45 in myocardial tissues of experimental animals were detected by Western blotting, while the corresponding myocardial tissues were stained with hematoxylin-eosin （HE） staining and Masson's staining, then histologically observed. Results Western blotting results showed that, compared with the control group, Cx43 expression in myocardial tissues of overworked rats decreased while Cx45 expression increased. HE staining and Masson's staining results showed that hypertrophy, rupture and interstitial fiber tissue hyperplasia were observed in myocardial fibers of overworked rats. Conclusion Overwork stress response may affect cardiac function as an independent factor and may even cause heart failure or arrhythmias and lead to death.
Animals ; Arrhythmias, Cardiac/metabolism* ; Connexin 43/metabolism* ; Connexins/metabolism* ; Heart Failure ; Myocardium ; Myocytes, Cardiac/metabolism* ; Rats

Dental pulp can initiate its damage repair after an injury of the pulp-dentin complex by rearrangement of odontoblasts and formation of newly differentiated odontoblast-like cells. Connexin 43 (Cx43) is one of the gap junction proteins that participates in multiple tissue repair processes. However, the role of Cx43 in the repair of the dental pulp remains unclear. This study aimed to determine the function of Cx43 in the odontoblast arrangement patterns and odontoblastic differentiation. Human teeth for in vitro experiments were acquired, and a pulp injury model in Sprague-Dawley rats was used for in vivo analysis. The odontoblast arrangement pattern and the expression of Cx43 and dentin sialophosphoprotein (DSPP) were assessed. To investigate the function of Cx43 in odontoblastic differentiation, we overexpressed or inhibited Cx43. The results indicated that polarized odontoblasts were arranged along the pulp-dentin interface and had high levels of Cx43 expression in the healthy teeth; however, the odontoblast arrangement pattern was slightly changed concomitant to an increase in the Cx43 expression in the carious teeth. Regularly arranged odontoblast-like cells had high levels of the Cx43 expression during the formation of mature dentin, but the odontoblast-like cells were not regularly arranged beneath immature osteodentin in the pulp injury models. Subsequent in vitro experiments demonstrated that Cx43 is upregulated during odontoblastic differentiation of the dental pulp cells, and inhibition or overexpression of Cx43 influence the odontoblastic differentiation. Thus, Cx43 may be involved in the maintenance of odontoblast arrangement patterns, and influence the pulp repair outcomes by the regulation of odontoblastic differentiation.
Animals ; Cell Differentiation ; Connexin 43 ; Dental Pulp ; Extracellular Matrix Proteins ; Odontoblasts ; Phosphoproteins ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To investigate the expression of connexin 43 (Cx43) in peripheral blood monocytes (PBMCs) from patients with acute coronary syndrome (ACS) and its clinical implications. METHODS: We prospectively collected the clinical data from 40 patients with ACS including 20 with unstable angina pectoris (UAP) and 20 with acute myocardial infarction (AMI) admitted in our department between January, 2018 and June, 2018, with 20 healthy subjects undergoing routine physical examinations serving as the control group. Peripheral blood samples were obtained from all the participants and plasma and PBMCs were separated. Enzyme-linked immunosorbent assay (ELISA) and turbidimetric inhibition immunoassay (TIIA) were used for analysis of plasma levels of interleukin (IL)-1β and high sensitive C-reactive protein (hs-CRP), respectively; real-time quantitative RT-PCR and Western blotting were used to detect the mRNA and protein levels of Cx43 in the PBMCs. RESULTS: Compared with the control group, the patients with UAP showed significantly increased plasma levels of IL-1β and hs-CRP ( < 0.001) and obviously elevated expressions of Cx43 at both mRNA and protein levels in the PBMCs ( < 0.001). Compared with the patients with UAP, the patients with AMI had significantly higher plasma IL-1β and hs-CRP levels ( < 0.001 and < 0.01) but lower expression levels of Cx43 in the PBMCs ( < 0.05). CONCLUSIONS Patients with UAP and AMI have activated inflammatory responses and reverse changes in Cx43 expression in the PBMCs, suggesting the different roles of Cx43 in the pathogenic mechanisms of different types of ACS.
Acute Coronary Syndrome ; Angina, Unstable ; C-Reactive Protein ; Connexin 43 ; Humans ; Monocytes

We studied the sex different nicotine effect on evoked population spike amplitudes (ePSA) and connexin (Cx) expression in the hippocampus CA1 area of gerbils. Acute doses of nicotine bitartrate (0.5 mg/kg: NT-0.5) slightly reduced ePSA in males but markedly augmented that in females. Acute NT (5.0 mg/kg) markedly increased the ePSA in all gerbils. Unlike acute NT-0.5, repeated NT-0.5 injection (twice a day for 7 days) significantly increased the ePSA in males and slightly affected the NT-0.5 effect in females. The Cx36 and Cx43 expression levels as well as Cx expressing neuronal populations were significantly increased by repeated NT-0.5 in in both male and female gerbils, and particularly, Cx43 expression was somewhat prominent in females. These results demonstrated a sex difference with respect to the nicotine effect on hippocampal bisynaptic excitability, irrelevant to connexin expression.
Animals ; Connexins ; Connexin 43 ; Female ; Gerbillinae* ; Hippocampus ; Male ; Neurons* ; Nicotine* ; Sex Characteristics*

OBJECTIVE: To investigate the effect of gap junction intercellular communication (GJIC) combined by connexin43 (Cx43) and its signal to the biobehavior of multiple myeloma (MM) cells, and its possible mechanism. METHODS: The mesenchymal stem cell (MSC) cells were isolated and cultured from patients with MM and normal donors. The expression of connexin43 (Cx43) in MSC cells from different sources was detected by RT-PCR and Western blot. The side population (SP) cells were sorted by flow cytometry (FCM). The effect of MSC cells from different sources to the cell cycle, Cx43 expression, colony formation in vitro, stem cell related genes expression, cytokines secretion and chemoresistance in MM SP cells as well as with or without Cx43 inhibitor 18α-glycyrrhetinic acid (18α-GA) was observed. RESULTS: There was no significantly difference between the MSC isolated from normal donor and MM patients. Western blot showed that Cx43 expression in SP cells was up-regulated when the cells were incubated with MSC, and medium containing 18α-GA could partially inhibit it, moreover, it was more significant in MSC cells of MM patients. The ability of colony formation of SP cells in vitro was higher than those of MM cells and MM-MSC could promote the colony formation in a co-culture manner. The effect of MM-MSC to SP cells was down-regulated after 18α-GA was added. RT-PCR showed that there was several important stem cell-related genes including c-myc, Oct-4 Klf-4, and Sox-2 were found in RPMI 8226 cells, but those cells were up-regulated in SP cells (P<0.001). Meanwhile, MM-MSC could up-regulate the expression of c-myc, Klf-4 and Sox-2 (P<0.001), but down-regulate Oct-4 gene in the SP cells. The expression of those genes decreased after 18α-GA was added, but showed no significant difference (P>0.05). Cytometry bead array assays showed that MM-MSCs could secrete high level of IL-6, but the levels of IL-6, IL-10 and TGF-β increased significantly when the MM-MSCs were co-cultured with SP cells (P<0.05), especially the levels of IL-6 and IL-10 were significantly higher than cultured alone. There was no significant change in the levels of bFGF and IL-17 before and after co-cultured. The levels of IL-6, IL-10 and TGF-β in supernatant decreased significantly after GJ inhibitor 18α-GA was added. PI/Annexin V assay showed that MM cells were sensitive to bortezomib (BTZ)-induced apoptosis, but the sensitivity for SP cells was weaker. The ratio of cell apoptosis was 75.2%±0.77% and 8.12%±0.86% (P<0.001), respectively. MM-MSC could down-regulate the cell apoptosis induced by BTZ, while the sensitivity of MM cells to BTZ could be partially recovered after GJ inhibitor was added. CONCLUSION MSC derived from MM patients can enhance GJIC to maintain its "hematopoiesis" by up-regulating the expression of Cx43 in MM cells, and at the same time promote cell proliferation and drug recistance by secreting multiple cytokines, which finally contributes to the relapse of MM.
Cell Communication ; Coculture Techniques ; Connexin 43 ; Humans ; Mesenchymal Stem Cells ; Multiple Myeloma