Gap junctions (GJs) exhibit a complex modus of assembly and degradation to maintain balanced intercellular communication (GJIC). Several growth factors, including vascular endothelial growth factor (VEGF), have been reported to disrupt cell-cell junctions and abolish GJIC. VEGF directly stimulates VEGF-receptor tyrosine kinases on endothelial cell surfaces. Exposing primary porcine pulmonary ar...

AIMS We investigated the effects of connexin43 (Cx43) down-regulation on endothelial function. METHODS AND RESULTS We used two different sequences of Cx43-specific small interference RNA (siRNA) to reduce de novo synthesis of Cx43 in human aortic endothelial cells and then examined the expression profiles, proliferation activity and viability, and angiogenic potential. The involvement of mito...

In the ovary, connexin-coupled gap junctions in granulosa cells play crucial roles in follicular and oocyte development as well as in corpus luteum formation. Our previous work has shown that theca cell-derived bone morphogenetic protein (BMP)4 and BMP7 decrease gap junction intercellular communication (GJIC) activity via the down-regulation of connexin43 (Cx43) expression in immortalized human...

Connexin43 (Cx43) is the most abundantly expressed member of the connexin (gap junction protein) family and the only one so far identified in mouse Leydig cell gap junctions. Mice lacking Cx43 were used to investigate its role in testicular androgen production and regulation. Testes from term fetuses were grafted under the kidney capsules of castrated adult males. After 3 weeks, serum from host...

Connexin43 (Cx43) is critical for maintaining electrical conduction across atrial muscle. During progressive ageing atrial conduction slows associating with increasing susceptibility to arrhythmias. Changes in Cx43 protein expression, or its phosphorylation status, can instigate changes in the conduction of the cardiac action potential. This study investigated whether increased levels of activa...

We have used mouse 27k cDNA arrays to compare gene expression patterns in four sets of three hearts each of neonatal wild types and four sets of three hearts each of littermates lacking the major cardiac gap junction protein, connexin43 (Cx43). Each individual set of hearts was hybridized against aliquots of an RNA standard prepared from selected mouse tissues, allowing calculation of variabili...

Connexin43 (Cx43) is known to have tumor-suppressive effects, but the underlying mechanisms are still poorly understood. In keratinocytes, we previously showed that the COOH-terminal domain of Cx43 directly interacts with the tumor suppressor Cav-1. We now show that rat epidermal keratinocytes (REK) that are reduced in Cx43 present features of epithelial-to-mesenchymal transition and are more i...

Cell transplantation of skeletal myoblasts (SMs) is one possible treatment for repairing cardiac tissue after myocardial injury. However, inappropriate electrical coupling between grafted SMs and host cardiomyocytes may be responsible for the arrhythmias observed in clinical trials of SM transplantation. Whether functional gap junctions occur between the two cell types remains controversial. We...

The gap junction protein, connexin43 (Cx43), plays an important role in skeletal biology. Previously, we have shown that Cx43 can enhance the signaling and transcriptional response to fibroblast growth factor 2 (FGF2) in osteoblasts by increasing protein kinase C-δ (PKCδ) activation to affect Runx2 activity. In the present study, we show by luciferase reporter assays that the ERK signaling casc...

Mutations in the GJA1 gene coding for connexin43 (Cx43) cause oculodentodigital dysplasia (ODDD), a pleiotropic human disorder with characteristic morphologic anomalies of face, teeth, bones and digits. Interdigital webbings, also called syndactylies, are a characteristic phenotype of this disease showing high intra- and interfamilial penetrance. Therefore, we decided to study the molecular bas...