The Use of Connexin-Based Therapeutic Approaches to Target Inflammatory Diseases

  • Simon J. O’Carroll
  • David L. Becker
  • Joanne O. Davidson
  • Alistair J. Gunn
  • Louise F. B. Nicholson
  • Colin R. Green
Part of the Methods in Molecular Biology book series (MIMB, volume 1037)


Alterations in Connexin43 (Cx43) expression levels have been shown to play a role in inflammatory processes including skin wounding and neuroinflammation. Cx43 protein levels increase following a skin wound and can inhibit wound healing. Increased Cx43 has been observed following stroke, epilepsy, ischemia, optic nerve damage, and spinal cord injury with gap junctional communication and hemichannel opening leading to increased secondary damage via the inflammatory response. Connexin43 modulation has been identified as a potential target for protection and repair in neuroinflammation and skin wound repair. This review describes the use of a Cx43 specific antisense oligonucleotide (Cx43 AsODN) and peptide mimetics of the connexin extracellular loop domain to modulate Cx43 expression and/or function in inflammatory disorders of the skin and central nervous system. An overview of the role of connexin43 in inflammatory conditions, how antisense and peptide have allowed us to elucidate the role of Cx43 in these diseases, create models of diseases to test interventions and their potential for use clinically or in current clinical trials is presented. Antisense oligonucleotides are applied topically and have been used to improve wound healing following skin injury. They have also been used to develop ex vivo models of neuroinflammatory diseases that will allow testing of intervention strategies. The connexin mimetic peptides have shown potential in a number of neuroinflammatory disorders in ex vivo models as well as in vivo when delivered directly to the injury site or when delivered systemically.

Key words

Connexin Antisense Mimetic peptide Inflammation Wound healing 


  1. 1.
    Nolte C et al (2001) GFAP promoter-controlled EGFP-expressing transgenic mice: a tool to visualize astrocytes and astrogliosis in living brain tissue. Glia 33:72–86PubMedGoogle Scholar
  2. 2.
    Tabernero A, Medina JM, Giaume C (2006) Glucose metabolism and proliferation in glia: role of astrocytic gap junctions. J Neurochem 99:1049–1061PubMedGoogle Scholar
  3. 3.
    Liberto CM et al (2004) Pro-regenerative properties of cytokine-activated astrocytes. J Neurochem 89:1092–1100PubMedGoogle Scholar
  4. 4.
    Goodenough DA, Goliger JA, Paul DL (1996) Connexins, connexons, and intercellular communication. Annu Rev Biochem 65:475–502PubMedGoogle Scholar
  5. 5.
    Chanson M et al (2005) Gap junctional communication in tissue inflammation and repair. Biochim Biophys Acta 1711:197–207PubMedGoogle Scholar
  6. 6.
    Giaume C et al (2007) Glia: the fulcrum of brain diseases. Cell Death Differ 14:1324–1335PubMedGoogle Scholar
  7. 7.
    Scemes E et al (2007) Connexin and pannexin mediated cell-cell communication. Neuron Glia Biol 3:199–208PubMedCentralPubMedGoogle Scholar
  8. 8.
    Kielian T (2008) Glial connexins and gap junctions in CNS inflammation and disease. J Neurochem 106:1000–1016PubMedCentralPubMedGoogle Scholar
  9. 9.
    John SA et al (1999) Connexin-43 hemichannels opened by metabolic inhibition. J Biol Chem 274:236–240PubMedGoogle Scholar
  10. 10.
    Haghikia A et al (2008) Intracellular application of TNF-alpha impairs cell to cell communication via gap junctions in glioma cells. J Neurooncol 86:143–152PubMedGoogle Scholar
  11. 11.
    Fonseca CG, Green CR, Nicholson LF (2002) Upregulation in astrocytic connexin 43 gap junction levels may exacerbate generalized seizures in mesial temporal lobe epilepsy. Brain Res 929:105–116PubMedGoogle Scholar
  12. 12.
    Budd SL, Lipton SA (1998) Calcium tsunamis: do astrocytes transmit cell death messages via gap junctions during ischemia? Nat Neurosci 1:431–432PubMedGoogle Scholar
  13. 13.
    Oguro K et al (2001) Global ischemia-induced increases in the gap junctional proteins connexin 32 (Cx32) and Cx36 in hippocampus and enhanced vulnerability of Cx32 knock-out mice. J Neurosci 21:7534–7542PubMedGoogle Scholar
  14. 14.
    Contreras JE et al (2004) Role of connexin-based gap junction channels and hemichannels in ischemia-induced cell death in nervous tissue. Brain Res Brain Res Rev 47:290–303PubMedCentralPubMedGoogle Scholar
  15. 15.
    Haupt C, Witte OW, Frahm C (2007) Up-regulation of Connexin43 in the glial scar following photothrombotic ischemic injury. Mol Cell Neurosci 35:89–99PubMedGoogle Scholar
  16. 16.
    Davidson JO et al (2012) Connexin hemichannel blockade improves outcomes in a model of fetal ischemia. Ann Neurol 71:121–132PubMedGoogle Scholar
  17. 17.
    Lee IH et al (2005) Glial and neuronal connexin expression patterns in the rat spinal cord during development and following injury. J Comp Neurol 489:1–10PubMedGoogle Scholar
  18. 18.
    Theriault E et al (1997) Connexin43 and astrocytic gap junctions in the rat spinal cord after acute compression injury. J Comp Neurol 382:199–214PubMedGoogle Scholar
  19. 19.
    O'Carroll SJ et al (2008) Connexin 43 mimetic peptides reduce swelling, astrogliosis, and neuronal cell death after spinal cord injury. Cell Commun Adhes 15:27–42PubMedGoogle Scholar
  20. 20.
    Cronin M et al (2008) Blocking connexin43 expression reduces inflammation and improves functional recovery after spinal cord injury. Mol Cell Neurosci 39(2):152–60PubMedGoogle Scholar
  21. 21.
    Frantseva MV et al (2002) Specific gap junctions enhance the neuronal vulnerability to brain traumatic injury. J Neurosci 22:644–653PubMedGoogle Scholar
  22. 22.
    Frantseva MV, Kokarovtseva L, Perez Velazquez JL (2002) Ischemia-induced brain damage depends on specific gap-junctional coupling. J Cereb Blood Flow Metab 22:453–462PubMedGoogle Scholar
  23. 23.
    Qiu C et al (2003) Targeting connexin43 expression accelerates the rate of wound repair. Curr Biol 13:1697–1703PubMedGoogle Scholar
  24. 24.
    Green CR et al (2001) Spatiotemporal depletion of connexins using antisense oligonucleotides. In: Bruzzone R, Giaume C (eds) Methods in molecular biology; connexin methods and protocols. Humana Press Inc., Totawa, NJ, pp 175–185Google Scholar
  25. 25.
    Nakase T et al (2004) Increased apoptosis and inflammation after focal brain ischemia in mice lacking connexin43 in astrocytes. Am J Pathol 164:2067–2075PubMedCentralPubMedGoogle Scholar
  26. 26.
    Siushansian R et al (2001) Connexin43 null mutation increases infarct size after stroke. J Comp Neurol 440:387–394PubMedGoogle Scholar
  27. 27.
    Takahashi DK, Vargas JR, Wilcox KS (2010) Increased coupling and altered glutamate transport currents in astrocytes following kainic-acid-induced status epilepticus. Neurobiol Dis 40:573–585PubMedCentralPubMedGoogle Scholar
  28. 28.
    Eugenin EA et al (2001) Microglia at brain stab wounds express connexin 43 and in vitro form functional gap junctions after treatment with interferon-gamma and tumor necrosis factor-alpha. Proc Natl Acad Sci USA 98:4190–4195PubMedCentralPubMedGoogle Scholar
  29. 29.
    Garg S, Md Syed M, Kielian T (2005) Staphylococcus aureus-derived peptidoglycan induces Cx43 expression and functional gap junction intercellular communication in microglia. J Neurochem 95:475–483PubMedCentralPubMedGoogle Scholar
  30. 30.
    Shaikh SB et al (2012) AGEs-RAGE mediated up-regulation of connexin43 in activated human microglial CHME-5 cells. Neurochem Int 60:640–651PubMedGoogle Scholar
  31. 31.
    Ye ZC et al (2003) Functional hemichannels in astrocytes: a novel mechanism of glutamate release. J Neurosci 23:3588–3596PubMedGoogle Scholar
  32. 32.
    Takeuchi H et al (2006) Tumor necrosis factor-alpha induces neurotoxicity via glutamate release from hemichannels of activated microglia in an autocrine manner. J Biol Chem 281:21362–21368PubMedGoogle Scholar
  33. 33.
    Kang J et al (2008) Connexin 43 hemichannels are permeable to ATP. J Neurosci 28:4702–4711PubMedCentralPubMedGoogle Scholar
  34. 34.
    John GR et al (1999) IL-1beta differentially regulates calcium wave propagation between primary human fetal astrocytes via pathways involving P2 receptors and gap junction channels. Proc Natl Acad Sci USA 96:11613–11618PubMedCentralPubMedGoogle Scholar
  35. 35.
    Retamal MA et al (2007) Cx43 hemichannels and gap junction channels in astrocytes are regulated oppositely by proinflammatory cytokines released from activated microglia. J Neurosci 27:13781–13792PubMedGoogle Scholar
  36. 36.
    Morita M et al (2007) Dual regulation of astrocyte gap junction hemichannels by growth factors and a pro-inflammatory cytokine via the mitogen-activated protein kinase cascade. Glia 55:508–515PubMedGoogle Scholar
  37. 37.
    Orellana JA et al (2009) Modulation of brain hemichannels and gap junction channels by pro-inflammatory agents and their possible role in neurodegeneration. Antioxid Redox Signal 11:369–399PubMedCentralPubMedGoogle Scholar
  38. 38.
    Retamal MA et al (2006) S-nitrosylation and permeation through connexin 43 hemichannels in astrocytes: induction by oxidant stress and reversal by reducing agents. Proc Natl Acad Sci USA 103:4475–4480PubMedCentralPubMedGoogle Scholar
  39. 39.
    Contreras JE et al (2002) Metabolic inhibition induces opening of unapposed connexin 43 gap junction hemichannels and reduces gap junctional communication in cortical astrocytes in culture. Proc Natl Acad Sci USA 99:495–500PubMedCentralPubMedGoogle Scholar
  40. 40.
    Orellana JA et al (2010) Hypoxia in high glucose followed by reoxygenation in normal glucose reduces the viability of cortical astrocytes through increased permeability of connexin 43 hemichannels. Glia 58:329–343PubMedCentralPubMedGoogle Scholar
  41. 41.
    Froger N et al (2010) Inhibition of cytokine-induced connexin43 hemichannel activity in astrocytes is neuroprotective. Mol Cell Neurosci 45:37–46PubMedGoogle Scholar
  42. 42.
    Kamibayashi Y et al (1993) Expression of gap junction proteins connexin 26 and 43 is modulated during differentiation of keratinocytes in newborn mouse epidermis. J Invest Dermatol 101:773–778PubMedGoogle Scholar
  43. 43.
    Fitzgerald DJ et al (1994) Expression and function of connexin in normal and transformed human keratinocytes in culture. Carcinogenesis 15:1859–1865PubMedGoogle Scholar
  44. 44.
    Goliger JA, Paul DL (1994) Expression of gap junction proteins Cx26, Cx31.1, Cx37, and Cx43 in developing and mature rat epidermis. Dev Dyn 200:1–13PubMedGoogle Scholar
  45. 45.
    Di WL et al (2001) Multiple epidermal connexins are expressed in different keratinocyte subpopulations including connexin 31. J Invest Dermatol 117:958–964PubMedGoogle Scholar
  46. 46.
    Lampe PD et al (2000) Phosphorylation of connexin43 on serine368 by protein kinase C regulates gap junctional communication. J Cell Biol 149:1503–1512PubMedCentralPubMedGoogle Scholar
  47. 47.
    Richard G (2000) Connexins: a connection with the skin. Exp Dermatol 9:77–96PubMedGoogle Scholar
  48. 48.
    Richard G (2005) Connexin disorders of the skin. Clin Dermatol 23:23–32PubMedGoogle Scholar
  49. 49.
    Salomon D et al (1994) Topography of mammalian connexins in human skin. J Invest Dermatol 103:240–247PubMedGoogle Scholar
  50. 50.
    Richards TS et al (2004) Protein kinase C spatially and temporally regulates gap junctional communication during human wound repair via phosphorylation of connexin43 on serine368. J Cell Biol 167:555–562PubMedCentralPubMedGoogle Scholar
  51. 51.
    Coutinho P et al (2003) Dynamic changes in connexin expression correlate with key events in the wound healing process. Cell Biol Int 27:525–541PubMedGoogle Scholar
  52. 52.
    Pistorio AL, Ehrlich HP (2011) Modulatory effects of connexin-43 expression on gap junction intercellular communications with mast cells and fibroblasts. J Cell Biochem 112:1441–1449PubMedCentralPubMedGoogle Scholar
  53. 53.
    Martin P (1997) Wound healing–aiming for perfect skin regeneration. Science 276:75–81PubMedGoogle Scholar
  54. 54.
    Mori R et al (2006) Acute downregulation of connexin43 at wound sites leads to a reduced inflammatory response, enhanced keratinocyte proliferation and wound fibroblast migration. J Cell Sci 119:5193–5203PubMedGoogle Scholar
  55. 55.
    Oviedo-Orta E, Howard Evans W (2004) Gap junctions and connexin-mediated communication in the immune system. Biochim Biophys Acta 1662:102–112PubMedGoogle Scholar
  56. 56.
    Singer AJ, Clark RA (1999) Cutaneous wound healing. N Engl J Med 341:738–746PubMedGoogle Scholar
  57. 57.
    Werner S, Grose R (2003) Regulation of wound healing by growth factors and cytokines. Physiol Rev 83:835–870PubMedGoogle Scholar
  58. 58.
    Ashcroft GS et al (1999) Mice lacking Smad3 show accelerated wound healing and an impaired local inflammatory response. Nat Cell Biol 1:260–266PubMedGoogle Scholar
  59. 59.
    Martin P et al (2003) Wound healing in the PU.1 null mouse–tissue repair is not dependent on inflammatory cells. Curr Biol 13:1122–1128PubMedGoogle Scholar
  60. 60.
    Dovi JV, Szpaderska AM, DiPietro LA (2004) Neutrophil function in the healing wound: adding insult to injury? Thromb Haemost 92:275–280PubMedGoogle Scholar
  61. 61.
    Adzick NS, Longaker MT (1992) Scarless fetal healing. Therapeutic implications. Ann Surg 215:3–7PubMedCentralPubMedGoogle Scholar
  62. 62.
    Hopkinson-Woolley J et al (1994) Macrophage recruitment during limb development and wound healing in the embryonic and foetal mouse. J Cell Sci 107(Pt 5):1159–1167PubMedGoogle Scholar
  63. 63.
    Redd MJ et al (2004) Wound healing and inflammation: embryos reveal the way to perfect repair. Philos Trans R Soc Lond B Biol Sci 359:777–784PubMedCentralPubMedGoogle Scholar
  64. 64.
    Whitby DJ, Ferguson MW (1991) Immunohistochemical localization of growth factors in fetal wound healing. Dev Biol 147:207–215PubMedGoogle Scholar
  65. 65.
    Roberts AB et al (1986) Transforming growth factor type beta: rapid induction of fibrosis and angiogenesis in vivo and stimulation of collagen formation in vitro. Proc Natl Acad Sci USA 83:4167–4171PubMedCentralPubMedGoogle Scholar
  66. 66.
    Mustoe T (2004) Understanding chronic wounds: a unifying hypothesis on their pathogenesis and implications for therapy. Am J Surg 187:65S–70SPubMedGoogle Scholar
  67. 67.
    Schreml S et al (2010) Wound healing in the 21st century. J Am Acad Dermatol 63:866–881PubMedGoogle Scholar
  68. 68.
    Saitoh M et al (1997) Changes in the expression of gap junction proteins (connexins) in hamster tongue epithelium during wound healing and carcinogenesis. Carcinogenesis 18:1319–1328PubMedGoogle Scholar
  69. 69.
    Goliger JA, Paul DL (1995) Wounding alters epidermal connexin expression and gap junction-mediated intercellular communication. Mol Biol Cell 6:1491–1501PubMedCentralPubMedGoogle Scholar
  70. 70.
    Brandner JM et al (2004) Connexins 26, 30, and 43: differences among spontaneous, chronic, and accelerated human wound healing. J Invest Dermatol 122:1310–1320PubMedGoogle Scholar
  71. 71.
    Clark RA (1985) Cutaneous tissue repair: basic biologic considerations. I. J Am Acad Dermatol 13:701–725PubMedGoogle Scholar
  72. 72.
    Gailit J, Clark RA (1994) Wound repair in the context of extracellular matrix. Curr Opin Cell Biol 6:717–725PubMedGoogle Scholar
  73. 73.
    Pollok S et al (2011) Connexin 43 mimetic peptide Gap27 reveals potential differences in the role of Cx43 in wound repair between diabetic and non-diabetic cells. J Cell Mol Med 15:861–873PubMedGoogle Scholar
  74. 74.
    Solan JL et al (2003) Connexin43 phosphorylation at S368 is acute during S and G2/M and in response to protein kinase C activation. J Cell Sci 116:2203–2211PubMedGoogle Scholar
  75. 75.
    van Zeijl L et al (2007) Regulation of connexin43 gap junctional communication by phosphatidylinositol 4,5-bisphosphate. J Cell Biol 177:881–891PubMedCentralPubMedGoogle Scholar
  76. 76.
    Duffy HS, Delmar M, Spray DC (2002) Formation of the gap junction nexus: binding partners for connexins. J Physiol Paris 96:243–249PubMedGoogle Scholar
  77. 77.
    Butkevich E et al (2004) Drebrin is a novel connexin-43 binding partner that links gap junctions to the submembrane cytoskeleton. Curr Biol 14:650–658PubMedGoogle Scholar
  78. 78.
    Giepmans BN et al (2001) Gap junction protein connexin-43 interacts directly with microtubules. Curr Biol 11:1364–1368PubMedGoogle Scholar
  79. 79.
    Li W, Hertzberg EL, Spray DC (2005) Regulation of connexin43-protein binding in astrocytes in response to chemical ischemia/hypoxia. J Biol Chem 280:7941–7948PubMedGoogle Scholar
  80. 80.
    Shaw RM et al (2007) Microtubule plus-end-tracking proteins target gap junctions directly from the cell interior to adherens junctions. Cell 128:547–560PubMedCentralPubMedGoogle Scholar
  81. 81.
    Theiss C, Meller K (2002) Microinjected anti-actin antibodies decrease gap junctional intercellular commmunication in cultured astrocytes. Exp Cell Res 281:197–204PubMedGoogle Scholar
  82. 82.
    Wei CJ et al (2005) Connexin43 associated with an N-cadherin-containing multiprotein complex is required for gap junction formation in NIH3T3 cells. J Biol Chem 280:19925–19936PubMedGoogle Scholar
  83. 83.
    Wei CJ, Xu X, Lo CW (2004) Connexins and cell signaling in development and disease. Annu Rev Cell Dev Biol 20:811–838PubMedGoogle Scholar
  84. 84.
    Spray DC, Rozental R, Srinivas M (2002) Prospects for rational development of pharmacological gap junction channel blockers. Curr Drug Targets 3:455–464PubMedGoogle Scholar
  85. 85.
    Iacobas DA, Iacobas S, Spray DC (2007) Connexin-dependent transcellular transcriptomic networks in mouse brain. Prog Biophys Mol Biol 94:169–185PubMedGoogle Scholar
  86. 86.
    Iacobas DA, Iacobas S, Spray DC (2007) Connexin43 and the brain transcriptome of newborn mice. Genomics 89:113–123PubMedCentralPubMedGoogle Scholar
  87. 87.
    Spray DC, Iacobas DA (2007) Organizational principles of the connexin-related brain transcriptome. J Membr Biol 218:39–47PubMedGoogle Scholar
  88. 88.
    Juszczak GR, Swiergiel AH (2009) Properties of gap junction blockers and their behavioural, cognitive and electrophysiological effects: animal and human studies. Prog Neuropsychopharmacol Biol Psychiatry 33:181–198PubMedGoogle Scholar
  89. 89.
    Evans WH, Boitano S (2001) Connexin mimetic peptides: specific inhibitors of gap-junctional intercellular communication. Biochem Soc Trans 29:606–612PubMedGoogle Scholar
  90. 90.
    Das S et al (2008) Protection of retinal cells from ischemia by a novel gap junction inhibitor. Biochem Biophys Res Commun 373:504–508PubMedCentralPubMedGoogle Scholar
  91. 91.
    Nodin C, Nilsson M, Blomstrand F (2005) Gap junction blockage limits intercellular spreading of astrocytic apoptosis induced by metabolic depression. J Neurochem 94:1111–1123PubMedGoogle Scholar
  92. 92.
    Rawanduzy A et al (1997) Effective reduction of infarct volume by gap junction blockade in a rodent model of stroke. J Neurosurg 87:916–920PubMedGoogle Scholar
  93. 93.
    Law LY et al (2006) In vitro optimization of antisense oligodeoxynucleotide design: an example using the connexin gene family. J Biomol Tech 17:270–282PubMedCentralPubMedGoogle Scholar
  94. 94.
    Becker DL et al (1999) Roles for alpha 1 connexin in morphogenesis of chick embryos revealed using a novel antisense approach. Dev Genet 24:33–42PubMedGoogle Scholar
  95. 95.
    Wagner RW (1994) Gene inhibition using antisense oligodeoxynucleotides. Nature 372:333–335PubMedGoogle Scholar
  96. 96.
    Myers KJ, Dean NM (2000) Sensible use of antisense: how to use oligonucleotides as research tools. Trends Pharmacol Sci 21:19–23PubMedGoogle Scholar
  97. 97.
    Phillips MI, Zhang YC (2000) Basic principles of using antisense oligonucleotides in vivo. Methods Enzymol 313:46–56PubMedGoogle Scholar
  98. 98.
    Yoon JJ et al (2010) Effect of low Mg2+ and bicuculline on cell survival in hippocampal slice cultures. Int J Neurosci 120:752–759PubMedGoogle Scholar
  99. 99.
    Yoon JJ et al (2010) A novel method of organotypic brain slice culture using connexin-specific antisense oligodeoxynucleotides to improve neuronal survival. Brain Res 1353:194–203PubMedGoogle Scholar
  100. 100.
    Danesh-Meyer HV et al (2008) Connexin43 antisense oligodeoxynucleotide treatment down-regulates the inflammatory response in an in vitro interphase organotypic culture model of optic nerve ischaemia. J Clin Neurosci 15:1253–1263PubMedGoogle Scholar
  101. 101.
    Wang CM et al (2007) Abnormal connexin expression underlies delayed wound healing in diabetic skin. Diabetes 56:2809–2817PubMedGoogle Scholar
  102. 102.
    Coutinho P et al (2005) Limiting burn extension by transient inhibition of Connexin43 expression at the site of injury. Br J Plast Surg 58:658–667PubMedGoogle Scholar
  103. 103.
    Zhang J et al (2010) A model for ex vivo spinal cord segment culture–a tool for analysis of injury repair strategies. J Neurosci Methods 192:49–57PubMedGoogle Scholar
  104. 104.
    Evans WH, Leybaert L (2007) Mimetic peptides as blockers of connexin channel-facilitated intercellular communication. Cell Commun Adhes 14:265–273PubMedGoogle Scholar
  105. 105.
    Ghatnekar GS et al (2009) Connexin43 carboxyl-terminal peptides reduce scar progenitor and promote regenerative healing following skin wounding. Regen Med 4:205–223PubMedCentralPubMedGoogle Scholar
  106. 106.
    Chaytor AT et al (1999) The endothelial component of cannabinoid-induced relaxation in rabbit mesenteric artery depends on gap junctional communication. J Physiol 520(Pt 2):539–550PubMedCentralPubMedGoogle Scholar
  107. 107.
    Mambetisaeva ET, Gire V, Evans WH (1999) Multiple connexin expression in peripheral nerve, Schwann cells, and Schwannoma cells. J Neurosci Res 57:166–175PubMedGoogle Scholar
  108. 108.
    Isakson BE, Evans WH, Boitano S (2001) Intercellular Ca2+ signaling in alveolar epithelial cells through gap junctions and by extracellular ATP. Am J Physiol Lung Cell Mole Physiol 280:L221–L228Google Scholar
  109. 109.
    Boitano S, Evans WH (2000) Connexin mimetic peptides reversibly inhibit Ca(2+) signaling through gap junctions in airway cells. Am J Physiol Lung Cell Mole Physiol 279:L623–L630Google Scholar
  110. 110.
    Dora KA et al (1999) Role of heterocellular Gap junctional communication in endothelium-dependent smooth muscle hyperpolarization: inhibition by a connexin-mimetic peptide. Biochem Biophys Res Commun 254:27–31PubMedGoogle Scholar
  111. 111.
    Kwak BR, Jongsma HJ (1999) Selective inhibition of gap junction channel activity by synthetic peptides. J Physiol 516(Pt 3):679–685PubMedCentralPubMedGoogle Scholar
  112. 112.
    Berthoud VM, Beyer EC, Seul KH (2000) Peptide inhibitors of intercellular communication. Am J Physiol Lung Cell Mole Physiol 279:L619–L622Google Scholar
  113. 113.
    De Vuyst E et al (2007) Connexin hemichannels and gap junction channels are differentially influenced by lipopolysaccharide and basic fibroblast growth factor. Mol Biol Cell 18:34–46PubMedCentralPubMedGoogle Scholar
  114. 114.
    Martin PE, Wall C, Griffith TM (2005) Effects of connexin-mimetic peptides on gap junction functionality and connexin expression in cultured vascular cells. Br J Pharmacol 144:617–627PubMedCentralPubMedGoogle Scholar
  115. 115.
    Braet K et al (2003) Photoliberating inositol-1,4,5-trisphosphate triggers ATP release that is blocked by the connexin mimetic peptide gap 26. Cell Calcium 33:37–48PubMedGoogle Scholar
  116. 116.
    Leybaert L et al (2003) Connexin channels, connexin mimetic peptides and ATP release. Cell Commun Adhes 10:251–257PubMedGoogle Scholar
  117. 117.
    Kandyba EE, Hodgins MB, Martin PE (2008) A murine living skin equivalent amenable to live-cell imaging: analysis of the roles of connexins in the epidermis. J Invest Dermatol 128:1039–1049PubMedGoogle Scholar
  118. 118.
    Wright CS et al (2009) Connexin mimetic peptides improve cell migration rates of human epidermal keratinocytes and dermal fibroblasts in vitro. Wound Repair Regen 17:240–249PubMedGoogle Scholar
  119. 119.
    Wright CS et al (2012) The connexin mimetic peptide Gap27 increases human dermal fibroblast migration in hyperglycemic and hyperinsulinemic conditions in vitro. J Cell Physiol 227:77–87PubMedGoogle Scholar
  120. 120.
    Orellana JA et al (2011) ATP and glutamate released via astroglial connexin 43 hemichannels mediate neuronal death through activation of pannexin 1 hemichannels. J Neurochem 118(5):826–840PubMedCentralPubMedGoogle Scholar
  121. 121.
    de Curtis M, Manfridi A, Biella G (1998) Activity-dependent pH shifts and periodic recurrence of spontaneous interictal spikes in a model of focal epileptogenesis. J Neurosci 18:7543–7551PubMedGoogle Scholar
  122. 122.
    Li J et al (2001) Upregulation of gap junction connexin 32 with epileptiform activity in the isolated mouse hippocampus. Neuroscience 105:589–598PubMedGoogle Scholar
  123. 123.
    Margineanu DG, Klitgaard H (2001) Can gap-junction blockade preferentially inhibit neuronal hypersynchrony vs. excitability? Neuropharmacology 41:377–383PubMedGoogle Scholar
  124. 124.
    Kohling R et al (2001) Prolonged epileptiform bursting induced by 0-Mg(2+) in rat hippocampal slices depends on gap junctional coupling. Neuroscience 105:579–587PubMedGoogle Scholar
  125. 125.
    Gigout S et al (2006) Effects of gap junction blockers on human neocortical synchronization. Neurobiol Dis 22:496–508PubMedGoogle Scholar
  126. 126.
    Szente M et al (2002) Involvement of electrical coupling in the in vivo ictal epileptiform activity induced by 4-aminopyridine in the neocortex. Neuroscience 115:1067–1078PubMedGoogle Scholar
  127. 127.
    Liu YW et al (2007) Adult neurogenesis in mesial temporal lobe epilepsy: a review of recent animal and human studies. Curr Pharm Biotechnol 8:187–194PubMedGoogle Scholar
  128. 128.
    Gao HM, Hong JS (2008) Why neurodegenerative diseases are progressive: uncontrolled inflammation drives disease progression. Trends Immunol 29:357–365PubMedGoogle Scholar
  129. 129.
    Yoon JJ et al (2010) Dose-dependent protective effect of connexin43 mimetic peptide against neurodegeneration in an ex vivo model of epileptiform lesion. Epilepsy Res 92:153–162PubMedGoogle Scholar
  130. 130.
    van der Linden JA et al (1993) Bicuculline increases the intracellular calcium response of CA1 hippocampal neurons to synaptic stimulation. Neurosci Lett 155:230–233PubMedGoogle Scholar
  131. 131.
    Nakase T et al (2003) Neuroprotective role of astrocytic gap junctions in ischemic stroke. Cell Commun Adhes 10:413–417PubMedGoogle Scholar
  132. 132.
    Blanc EM, Bruce-Keller AJ, Mattson MP (1998) Astrocytic gap junctional communication decreases neuronal vulnerability to oxidative stress-induced disruption of Ca2+ homeostasis and cell death. J Neurochem 70:958–970PubMedGoogle Scholar
  133. 133.
    Ozog MA, Siushansian R, Naus CC (2002) Blocked gap junctional coupling increases glutamate-induced neurotoxicity in neuron-astrocyte co-cultures. J Neuropathol Exp Neurol 61:132–141PubMedGoogle Scholar
  134. 134.
    Bragin A, Penttonen M, Buzsaki G (1997) Termination of epileptic afterdischarge in the hippocampus. J Neurosci 17:2567–2579PubMedGoogle Scholar
  135. 135.
    Jabs R, Seifert G, Steinhauser C (2008) Astrocytic function and its alteration in the epileptic brain. Epilepsia 49(Suppl 2):3–12PubMedGoogle Scholar
  136. 136.
    O'Connor ER et al (1998) Astrocytes from human hippocampal epileptogenic foci exhibit action potential-like responses. Epilepsia 39:347–354PubMedGoogle Scholar
  137. 137.
    Fitch MT et al (1999) Cellular and molecular mechanisms of glial scarring and progressive cavitation: in vivo and in vitro analysis of inflammation-induced secondary injury after CNS trauma. J Neurosci 19:8182–8198PubMedGoogle Scholar
  138. 138.
    Dusart I, Schwab ME (1994) Secondary cell death and the inflammatory reaction after dorsal hemisection of the rat spinal cord. Eur J Neurosci 6:712–724PubMedGoogle Scholar
  139. 139.
    Koshinaga M, Whittemore SR (1995) The temporal and spatial activation of microglia in fiber tracts undergoing anterograde and retrograde degeneration following spinal cord lesion. J Neurotrauma 12:209–222PubMedGoogle Scholar
  140. 140.
    Bush TG et al (1999) Leukocyte infiltration, neuronal degeneration, and neurite outgrowth after ablation of scar-forming, reactive astrocytes in adult transgenic mice. Neuron 23:297–308PubMedGoogle Scholar
  141. 141.
    Davalos D et al (2005) ATP mediates rapid microglial response to local brain injury in vivo. Nat Neurosci 8:752–758PubMedGoogle Scholar
  142. 142.
    Faulkner JR et al (2004) Reactive astrocytes protect tissue and preserve function after spinal cord injury. J Neurosci 24:2143–2155PubMedGoogle Scholar
  143. 143.
    Myer DJ et al (2006) Essential protective roles of reactive astrocytes in traumatic brain injury. Brain 129:2761–2772PubMedGoogle Scholar
  144. 144.
    Okada S et al (2006) Conditional ablation of Stat3 or Socs3 discloses a dual role for reactive astrocytes after spinal cord injury. Nat Med 12:829–834PubMedGoogle Scholar
  145. 145.
    Loane DJ, Byrnes KR (2010) Role of microglia in neurotrauma. Neurotherapeutics 7:366–377PubMedCentralPubMedGoogle Scholar
  146. 146.
    Brambilla R et al (2005) Inhibition of astroglial nuclear factor kappaB reduces inflammation and improves functional recovery after spinal cord injury. J Exp Med 202:145–156PubMedCentralPubMedGoogle Scholar
  147. 147.
    Horn KP et al (2008) Another barrier to regeneration in the CNS: activated macrophages induce extensive retraction of dystrophic axons through direct physical interactions. J Neurosci 28:9330–9341PubMedCentralPubMedGoogle Scholar
  148. 148.
    Decrock E et al (2009) Connexin-related signaling in cell death: to live or let die? Cell Death Differ 16:524–536PubMedGoogle Scholar
  149. 149.
    Basso DM, Beattie MS, Bresnahan JC (1995) A sensitive and reliable locomotor rating scale for open field testing in rats. J Neurotrauma 12:1–21PubMedGoogle Scholar
  150. 150.
    Abcouwer SF et al (2010) Effects of ischemic preconditioning and bevacizumab on apoptosis and vascular permeability following retinal ischemia-reperfusion injury. Invest Ophthalmol Vis Sci 51:5920–5933PubMedGoogle Scholar
  151. 151.
    Wilson CA et al (1995) Blood-retinal barrier breakdown following experimental retinal ischemia and reperfusion. Exp Eye Res 61:547–557PubMedGoogle Scholar
  152. 152.
    Zheng L et al (2007) Retinal ischemia and reperfusion causes capillary degeneration: similarities to diabetes. Invest Ophthalmol Vis Sci 48:361–367PubMedGoogle Scholar
  153. 153.
    Simard M et al (2003) Signaling at the gliovascular interface. J Neurosci 23:9254–9262PubMedGoogle Scholar
  154. 154.
    Cornell-Bell AH, Finkbeiner SM (1991) Ca2+ waves in astrocytes. Cell Calcium 12:185–204PubMedGoogle Scholar
  155. 155.
    Braet K et al (2001) Astrocyte-endothelial cell calcium signals conveyed by two signalling pathways. Eur J Neurosci 13:79–91PubMedGoogle Scholar
  156. 156.
    Edwards AD et al (2010) Neurological outcomes at 18 months of age after moderate hypothermia for perinatal hypoxic ischaemic encephalopathy: synthesis and meta-analysis of trial data. BMJ 340:c363PubMedCentralPubMedGoogle Scholar
  157. 157.
    Vannucci RC (2000) Hypoxic-ischemic encephalopathy. Am J Perinatol 17:113–120PubMedGoogle Scholar
  158. 158.
    Thornton JS et al (1998) Temporal and anatomical variations of brain water apparent diffusion coefficient in perinatal cerebral hypoxic-ischemic injury: relationships to cerebral energy metabolism. Magn Reson Med 39:920–927PubMedGoogle Scholar
  159. 159.
    Williams CE et al (1992) Outcome after ischemia in the developing sheep brain: an electroencephalographic and histological study. Ann Neurol 31:14–21PubMedGoogle Scholar
  160. 160.
    de Pina-Benabou MH et al (2005) Blockade of gap junctions in vivo provides neuroprotection after perinatal global ischemia. Stroke 36:2232–2237PubMedGoogle Scholar
  161. 161.
    Kondo RP et al (2000) Metabolic inhibition activates a non-selective current through connexin hemichannels in isolated ventricular myocytes. J Mol Cell Cardiol 32:1859–1872PubMedGoogle Scholar
  162. 162.
    Li H et al (1996) Properties and regulation of gap junctional hemichannels in the plasma membranes of cultured cells. J Cell Biol 134:1019–1030PubMedGoogle Scholar
  163. 163.
    Barkovich AJ, Truwit CL (1990) Brain damage from perinatal asphyxia: correlation of MR findings with gestational age. AJNR Am J Neuroradiol 11:1087–1096PubMedGoogle Scholar
  164. 164.
    Murray DM et al (2009) Early EEG findings in hypoxic-ischemic encephalopathy predict outcomes at 2 years. Pediatrics 124:e459–e467PubMedGoogle Scholar
  165. 165.
    Peng W et al (2009) Systemic administration of an antagonist of the ATP-sensitive receptor P2X7 improves recovery after spinal cord injury. Proc Natl Acad Sci USA 106:12489–12493PubMedCentralPubMedGoogle Scholar
  166. 166.
    Roelfsema V et al (2004) Window of opportunity of cerebral hypothermia for postischemic white matter injury in the near-term fetal sheep. J Cereb Blood Flow Metab 24:877–886PubMedGoogle Scholar
  167. 167.
    Franke H et al (2012) Pathophysiology of astroglial purinergic signalling. Purinergic Signal 8:629–657PubMedCentralPubMedGoogle Scholar
  168. 168.
    Orellana JA et al (2011) Hemichannels in the neurovascular unit and white matter under normal and inflamed conditions. CNS Neurol Disord Drug Targets 10:404–414PubMedGoogle Scholar
  169. 169.
    Neub A et al (2007) Biphasic regulation of AP-1 subunits during human epidermal wound healing. J Invest Dermatol 127:2453–2462PubMedGoogle Scholar
  170. 170.
    Leithe E, Brech A, Rivedal E (2006) Endocytic processing of connexin43 gap junctions: a morphological study. Biochem J 393:59–67PubMedCentralPubMedGoogle Scholar
  171. 171.
    Gaietta G et al (2002) Multicolor and electron microscopic imaging of connexin trafficking. Science 296:503–507PubMedGoogle Scholar
  172. 172.
    Kretz M et al (2003) Altered connexin expression and wound healing in the epidermis of connexin-deficient mice. J Cell Sci 116:3443–3452PubMedGoogle Scholar
  173. 173.
    Dovi JV, He LK, DiPietro LA (2003) Accelerated wound closure in neutrophil-depleted mice. J Leukoc Biol 73:448–455PubMedGoogle Scholar
  174. 174.
    Rossi D, Zlotnik A (2000) The biology of chemokines and their receptors. Annu Rev Immunol 18:217–242PubMedGoogle Scholar
  175. 175.
    Sarieddine MZ et al (2009) Connexin43 modulates neutrophil recruitment to the lung. J Cell Mol Med 13:4560–4570PubMedGoogle Scholar
  176. 176.
    Zahler S et al (2003) Gap-junctional coupling between neutrophils and endothelial cells: a novel modulator of transendothelial migration. J Leukoc Biol 73:118–126PubMedGoogle Scholar
  177. 177.
    Mendoza-Naranjo A et al (2011) Functional gap junctions accumulate at the immunological synapse and contribute to T cell activation. J Immunol 187:3121–3132PubMedCentralPubMedGoogle Scholar
  178. 178.
    Cutroneo KR (2003) How is Type I procollagen synthesis regulated at the gene level during tissue fibrosis. J Cell Biochem 90:1–5PubMedGoogle Scholar
  179. 179.
    Postlethwaite AE et al (1987) Stimulation of the chemotactic migration of human fibroblasts by transforming growth factor beta. J Exp Med 165:251–256PubMedGoogle Scholar
  180. 180.
    Waggett AD, Benjamin M, Ralphs JR (2006) Connexin 32 and 43 gap junctions differentially modulate tenocyte response to cyclic mechanical load. Eur J Cell Biol 85:1145–1154PubMedGoogle Scholar
  181. 181.
    Falanga V (2005) Wound healing and its impairment in the diabetic foot. Lancet 366:1736–1743PubMedGoogle Scholar
  182. 182.
    Dinh TL, Veves A (2005) A review of the mechanisms implicated in the pathogenesis of the diabetic foot. Int J Low Extrem Wounds 4:154–159PubMedGoogle Scholar
  183. 183.
    Lucke T et al (1999) Upregulation of connexin 26 is a feature of keratinocyte differentiation in hyperproliferative epidermis, vaginal epithelium, and buccal epithelium. J Invest Dermatol 112:354–361PubMedGoogle Scholar
  184. 184.
    Djalilian AR et al (2006) Connexin 26 regulates epidermal barrier and wound remodeling and promotes psoriasiform response. J Clin Invest 116:1243–1253PubMedCentralPubMedGoogle Scholar
  185. 185.
    Abdullah KM et al (1999) Cell-to-cell communication and expression of gap junctional proteins in human diabetic and nondiabetic skin fibroblasts: effects of basic fibroblast growth factor. Endocrine 10:35–41PubMedGoogle Scholar
  186. 186.
    Loots MA et al (1999) Cultured fibroblasts from chronic diabetic wounds on the lower extremity (non-insulin-dependent diabetes mellitus) show disturbed proliferation. Arch Dermatol Res 291:93–99PubMedGoogle Scholar
  187. 187.
    Brandner JM et al (2008) Expression of matrix metalloproteinases, cytokines, and connexins in diabetic and nondiabetic human keratinocytes before and after transplantation into an ex vivo wound-healing model. Diabetes Care 31:114–120PubMedGoogle Scholar
  188. 188.
    Thomas MP et al (1998) Organotypic brain slice cultures for functional analysis of alcohol-related disorders: novel versus conventional preparations. Alcohol Clin Exp Res 22:51–59PubMedGoogle Scholar
  189. 189.
    Riley C et al (2006) A peptide preparation protects cells in organotypic brain slices against cell death after glutamate intoxication. J Neural Transm 113:103–110PubMedGoogle Scholar
  190. 190.
    Thomas MP et al (1998) Survival and functional demonstration of interregional pathways in fore/midbrain slice explant cultures. Neuroscience 85:615–626PubMedGoogle Scholar
  191. 191.
    Muller D, Buchs PA, Stoppini L (1993) Time course of synaptic development in hippocampal organotypic cultures. Brain Res Dev Brain Res 71:93–100PubMedGoogle Scholar
  192. 192.
    Fabian-Fine R et al (2000) Age-dependent pre- and postsynaptic distribution of AMPA receptors at synapses in CA3 stratum radiatum of hippocampal slice cultures compared with intact brain. Eur J Neurosci 12:3687–3700PubMedGoogle Scholar
  193. 193.
    Braet K et al (2004) Calcium signal communication in the central nervous system. Biol Cell 96:79–91PubMedGoogle Scholar
  194. 194.
    Pekny M, Nilsson M (2005) Astrocyte activation and reactive gliosis. Glia 50:427–434PubMedGoogle Scholar
  195. 195.
    Stout CE et al (2002) Intercellular calcium signaling in astrocytes via ATP release through connexin hemichannels. J Biol Chem 277:10482–10488PubMedGoogle Scholar
  196. 196.
    Gomes P et al (2005) ATP release through connexin hemichannels in corneal endothelial cells. Invest Ophthalmol Vis Sci 46:1208–1218PubMedGoogle Scholar
  197. 197.
    Finley M et al (2004) Functional validation of adult hippocampal organotypic cultures as an in vitro model of brain injury. Brain Res 1001:125–132PubMedGoogle Scholar
  198. 198.
    Cho JS et al (2009) Transplantation of mesenchymal stem cells enhances axonal outgrowth and cell survival in an organotypic spinal cord slice culture. Neurosci Lett 454:43–48PubMedGoogle Scholar
  199. 199.
    Kim HM et al (2010) Organotypic spinal cord slice culture to study neural stem/progenitor cell microenvironment in the injured spinal cord. Exp Neurobiol 19:106–113PubMedCentralPubMedGoogle Scholar
  200. 200.
    Guzman-Lenis MS et al (2008) Analysis of FK506-mediated protection in an organotypic model of spinal cord damage: heat shock protein 70 levels are modulated in microglial cells. Neuroscience 155:104–113PubMedGoogle Scholar
  201. 201.
    Krassioukov AV et al (2002) An in vitro model of neurotrauma in organotypic spinal cord cultures from adult mice. Brain Res Brain Res Protoc 10:60–68PubMedGoogle Scholar
  202. 202.
    Hamann K et al (2008) Critical role of acrolein in secondary injury following ex vivo spinal cord trauma. J Neurochem 107:712–721PubMedCentralPubMedGoogle Scholar
  203. 203.
    Saruhashi Y, Matsusue Y, Hukuda S (2002) Effects of serotonin 1A agonist on acute spinal cord injury. Spinal Cord 40:519–523PubMedGoogle Scholar
  204. 204.
    Mazzone GL et al (2010) Kainate-induced delayed onset of excitotoxicity with functional loss unrelated to the extent of neuronal damage in the in vitro spinal cord. Neuroscience 168:451–462PubMedGoogle Scholar
  205. 205.
    Kawaja MD, Gage FH (1991) Reactive astrocytes are substrates for the growth of adult CNS axons in the presence of elevated levels of nerve growth factor. Neuron 7:1019–1030PubMedGoogle Scholar
  206. 206.
    Bonner JF et al (2011) Grafted neural progenitors integrate and restore synaptic connectivity across the injured spinal cord. J Neurosci 31:4675–4686PubMedCentralPubMedGoogle Scholar
  207. 207.
    Cao Q et al (2010) Transplantation of ciliary neurotrophic factor-expressing adult oligodendrocyte precursor cells promotes remyelination and functional recovery after spinal cord injury. J Neurosci 30:2989–3001PubMedCentralPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Simon J. O’Carroll
    • 1
  • David L. Becker
    • 2
  • Joanne O. Davidson
    • 3
  • Alistair J. Gunn
    • 3
  • Louise F. B. Nicholson
    • 1
  • Colin R. Green
    • 4
  1. 1.Department of Anatomy with Radiology, Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand
  2. 2.Department of Cell and Developmental BiologyUniversity College LondonLondonUK
  3. 3.Department of PhysiologyUniversity of AucklandAucklandNew Zealand
  4. 4.Department of Ophthalmology, Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand

Personalised recommendations