1 We have shown that the endocannabinoid anandamide and its stable analogue methanandamide relax rings of rabbit superior mesenteric artery through endothelium-dependent -independent mechanisms are unaffected by blockade NO synthase cyclooxygenase. 2 The component responses was attenuated gap junction inhibitor 18α-glycyrrhetinic acid (18α-GA; 50 μm), a synthetic connexin-mimetic peptide homologous to extracellular Gap 27 sequence connexin 43 (43Gap 27, SRPTEKTIFII; 300 μm). By contrast,...

The assembly of gap junctions was investigated in mammalian cells expressing connexin (Cx) 26, 32 and 43 fused to green, yellow or cyan fluorescent proteins (GFP, YFP, CFP). Targeting Cx32-CFP 43-GFP junctional communication inhibited treated with Brefeldin A, a drug that disassembles the Golgi. However constructed Cx26-GFP were only minimally affected by A. Nocodazole, microtubule disruptor, had little effect on Cx43-GFP junctions, but perturbed junctions. Co-expression Cx26-YFP A resulted...

AbstractConnexin hemichannels, that is, half gap junction channels (not connecting cells), have been implicated in the release of various messengers such as ATP and glutamate. We used connexin mimetic peptides, which are, small peptides mimicking a sequence on subunit, to investigate hemichannel functioning endothelial cell lines. Short exposure (30 min) synthetic first or second extracellular loop subunit strongly supressed dye uptake triggered by either intracellular InsP3elevation zero...

This study was undertaken to obtain direct evidence for the involvement of gap junctions in propagation intercellular Ca(2+) waves. Gap junction-deficient HeLa cells were transfected with plasmids encoding green fluorescent protein (GFP) fused cytoplasmic carboxyl termini connexin 43 (Cx43), 32 (Cx32), or 26 (Cx26). The subsequently expressed GFP-labeled rendered dye- and electrically coupled detected at plasma membranes points contact between adjacent cells. To correlate distribution...

Synthetic peptides homologous to the Gap 26 and 27 domains of first second extracellular loops major vascular connexins (Cx37, Cx40, Cx43) have been used investigate role gap junctions in endothelium-derived hyperpolarizing factor (EDHF)-type relaxations rat hepatic artery. These were designated 37,40 26, 43 37,43 27, 40 according connexin specificity. When administered at 600 μM, none individually affected maximal EDHF-type ACh. By contrast, 300 μM each, paired peptide combinations...

ABSTRACT Nonhealing cutaneous wounds, a major cause of morbidity and mortality, are difficult to treat. Recent studies suggest that significant increases in skin wound‐healing rates occur by altering gap junction intercellular communication (GJIC). As migration keratinocytes fibroblasts is an important feature wound healing, this study investigated whether cultured normal human epidermal dermal could be altered modulating GJIC via connexin mimetic peptides. First, HeLa cells stably...

During early wound healing (WH) events Connexin 43 (Cx43) is down-regulated at margins. In chronic margins, including diabetic wounds, Cx43 expression enhanced suggesting that down-regulation important for WH. We previously reported the mimetic peptide Gap27 blocks mediated intercellular communication and promotes skin cell migration of infant cells in vitro. present work we further investigated molecular mechanism action its therapeutic potential to improve WH tissue non-diabetic cells. Ex...

Three point mutations of the connexin26 (GJB2) gene associated with hereditary deafness were studied using in vitro expression systems. Mutation M34T results an amino acid substitution first transmembrane domain connexin protein, W77R is located second and W44C extracellular loop. Wild-type mutated vectors constructed transfected into communication-deficient HeLa cells to obtain transient proteins. Intercellular coupling was subsequently assessed by examining transfer Lucifer yellow between...

Abstract Recently, ATP has gained much interest as an extracellular messenger involved in the communication of calcium signals between cells. The mechanism release is, however, still a matter debate. In present study we investigated possible contribution connexin hemichannels or ion channels GP8, rat brain endothelial cell line. Release was triggered by photoactivation InsP 3 reducing concentration. Both trigger protocols induced significantly above baseline. ‐triggered completely blocked...

1. We have investigated the effects of connexin-mimetic peptides homologous to Gap 26 and 27 domains Cxs 37, 40 43 against gap junctional communication connexin expression in rat aortic endothelial cells (RAECs) A7r5 myocytes. 2. Immunostaining Western blot analysis confirmed presence junction plaques containing Cx43, but not Cx40, RAECs, whereas were evident cells. Expression Cx37 was limited RAECs absent from 3. Under control conditions calcein-loaded transferred dye approximately 70%...

Altered gap junction coupling of cardiac myocytes during ischemia may contribute to development lethal arrhythmias. The phosphoprotein connexin 43 (Cx43) is the major constituent junctions. Dephosphorylation Cx43 and uncoupling junctions occur ischemia, but significance phosphorylation in this setting unknown. Here we show that dephosphorylation synchronously contracting reversible, independent hypoxia, closely associated with cellular ATP levels. became profoundly dephosphorylated hypoxia...

We investigated the effects of rotigaptide (ZP123), a stable hexapeptide with antiarrhythmic properties, on gap junction mediated intercellular communication in contracting rat neonatal cardiac myocytes, HL‐1 cells derived from atrium and HeLa transfected cDNA encoding Cx43‐GFP, Cx32‐GFP, Cx26‐GFP, wild‐type Cx43 or Cx26. Intercellular was monitored before after treatment following microinjection small fluorescent dyes (MW<1 kDa). The communication‐modifying effect confined to expressing...

Gram-positive bacterial cell wall components including PGN (peptidoglycan) elicit a potent pro-inflammatory response in diverse types, endothelial cells, by activating TLR2 (Toll-like receptor 2) signalling. The functional integrity of the endothelium is under influence network gap junction intercellular communication channels composed Cxs (connexins) that also form hemichannels, signalling conduits are implicated ATP release and purinergic modulates Cx expression variety yet effects cells...

In the epidermis, remodelling of Connexin43 is a key event in wound closure. However, controversy between role connexin channel and non-channel functions exist. We compared impact SiRNA targeted to mimetic peptide Gap27 on scrape closure rates hemichannel signalling adult keratinocytes (AK) fibroblasts sourced from juvenile foreskin (JFF), human neonatal (HNDF) dermal tissue (ADF). The these agents, following 24 h exposure, GJA1 (encoding Connexin43), Ki67 TGF-β1 gene expression, pSmad3...

Chronic wounds represent a major healthcare and economic problem worldwide. Advanced wound dressings that incorporate bioactive compounds have great potential for improving outcomes in patients with chronic but significant challenges designing treatments are effective long‐standing, nonhealing wounds. Here, an optimized healing gel was developed delivers syndecan‐4 proteoliposomes (“syndesomes”) fibroblast growth factor‐2 (FGF‐2) to enhance diabetic healing. In vitro studies demonstrate...