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Instituto Nacional de Neurología y Neurocirugía

2019, Number 2

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Arch Neurocien 2019; 24 (2)

Possible role of HmInx2 during development of the central nervous system of the medicinal leech (Hirudo medicinalis)

Sánchez-González A, Perzabal-Corona M, Portillo-Lopez A

Language: English
References: 15
Page: 22-33
PDF size: 831.02 Kb.


ABSTRACT

There is broad gap junctional (GJ) coupling among cells of the Central Nervous System (CNS) during early neurogenesis in the medicinal leech (Hirudo medicinalis). To assay potential roles of the expression of a specific GJ protein of the leech Innexin family, two techniques to block the formation of GJs at early stages of development were tested: (1) knock-down of expression by using RNA interference intracellularly, and (2) blocking assembly of GJs extracellularly with mimetic peptides. The work reported here focused on HmInx2, which has been reported to be expressed exclusively in glial cells, particularly during gangliogenesis as well as later stages of central nervous system (CNS) development. siRNA was delivered on gold particles by means of biolistics (gene gun), while mimetic peptides were delivered via extracellular microinjection. Initial results suggest that HmInx2 is involved in interactions, possibly adhesive, between the macroglia (packet and neuropil glia) that give rise to ganglionic structure, since neurons appear disorganized and displaced following siRNA intervention. The effects of mimetic peptide injection are similar but subtler, indicating that formation of HmInx2-based GJs is only partially affected by this extracellular reagent. These observations are consistent with the hypothesis that GJs between cellular elements of the CNS are necessary in early development for attaining and maintaining structural integrity. GJ-mediated adhesion is proposed to play an important role in early neural development in the medicinal leech, as it does in mammalian nervous systems.


REFERENCES

  1. Oshima A, Matsuzawa T, Nishikawa K, Fujiyoshi Y. Oligomeric Structure and functional characterization of caenorhabditis elegans Innexin-6 Gap junction protein. J Biol Chem 2013; 288(15), 10513-10521. http://doi. org/10.1074/jbc.M112.428383

  2. Panchin YV. Evolution of gap junction proteins-the pannexin alternative. J Exp Biol 2005; 208(8):1415-9. Review. PubMed PMID: 15802665.

  3. Dykes IM, Freeman FM, Bacon JP, Davies JA. Molecular basis of gap junctional communication in the CNS of the leech Hirudo medicinalis. J Neurosci 2004;2824(4):886-94. PubMed PMID: 14749433.

  4. Dykes IM, Macagno ER. Molecular characterization and embryonic expression of innexins in the leech Hirudo medicinalis. Dev Genes Evol 2006; 216: 185–197 DOI:10.1007/s00427-005-0048-1

  5. Nielsen MS, Axelsen LN, Sorgen PL, Verma V, Delmar M, Holstein NH. Gap Junctions. Comprehensive Physiology 2012; 2(3). http://doi.org/10.1002/cphy.c110051

  6. Lehmann C, Lechner H, Löer B, Knieps M, Herrmann S, Famulok M, Hoch M. Heteromerization of Innexin Gap junction proteins regulates epithelial tissue Organization in Drosophila. Mol Biol Cell 2006; 17(4):1676-1685. http://doi.org/10.1091/mbc.E05-11-1059

  7. Baker MW, Macagno ER. Gap junction proteins and the wiring (Rewiring) of neuronal circuits. Dev Neurobiol 2016; 77(5):575-586. doi: 10.1002/dneu.22429. Epub. PubMed PMID: 27512961.

  8. Yazdani N, Firme CP 3rd, Macagno ER, Baker MW.Expression of a dominant negative mutant innexin in identified neurons and glial cells reveals selective interactions among gap junctional proteins. Dev Neurobiol 2013; 73(8):571-86. doi: 10.1002/dneu.22082. Epub 2013 PubMed PMID: 23447124.9

  9. Marin-Burgin A, Eisenhart F, Kristan M, French K. Embryonic electrical connections appear to prefigure a behavioral circuit in the leech CNS. J Comp Physiol A. 2006; 192: 123–133 DOI 10.1007/s00359-005-0055-8.

  10. Wang J, Locovei S, Keane RW and Dahl G. Modulation of membrane channel currents by gap junction protein mimetic peptides: size matters. Am J Physiol Cell Physiol 2007;293: C1112-C1119.

  11. Dahl G. Gap junction-mimetic peptides do work, but in unexpected ways. Cell Commun Adhes 2009; 14(6):259- 64. doi:10.1080/ 15419060801891018. Review.PubMed PMID: 18392993.

  12. Bauer R, Lehmann C, Martini J, Eckardt F, Hoch M. Gap Junction Channel Protein Innexin 2 Is Essential for Epithelial Morphogenesis in the Drosophila Embryo. Mol Biol Cell 2004;15, 2992–3004.

  13. Stebbings L, Todman A, Phelan MG, Bacon JP, Davies JA. Two Drosophila innexins are expressed in overlapping domains and cooperate to form gap-junction channels. Mol Biol Cell 2000;11, 2459–2470.

  14. Bauer R, Lehmann C, Fuss B, Eckardt F, Hoch M. The Drosophila gap junction channel gene innexin 2 controls foregut development in response to Wingless signalling. J Cell Sci 2002; 115, 1859–67.

  15. Shefi O, Simonnet C, Baker MW, Glass JR, Macagno ER, Groisman A. Microtargeted gene silencing and ectopic expression in live embryos using biolistic delivery with a pneumatic capillary gun. J Neurosci 2006; 7, 26(23):6119- 23. PubMed PMID: 16763019.




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