Klin Monbl Augenheilkd 2011; 228(6): 520-524
DOI: 10.1055/s-0031-1273254
Übersicht

© Georg Thieme Verlag KG Stuttgart · New York

Physiologie des humanen Hornhautendothels – neue Erkenntnisse durch elektrophysiologische Untersuchungen

Physiology of the Human Corneal Endothelium – New Insights from Electrophysiological InvestigationsS. Mergler1 , U. Pleyer1
  • 1Klinik für Augenheilkunde, Charité Universitätsmedizin Berlin
Further Information

Publication History

Eingegangen: 12.2.2011

Angenommen: 18.2.2011

Publication Date:
03 May 2011 (online)

Zusammenfassung

Die Identifizierung von apoptotischen oder geschädigten humanen Hornhautendothel(HCE)-Zellen ist derzeit auf eine morphologische Beurteilung und Vitalfärbung begrenzt. Spezielle elektrophysiologische Untersuchungen könnten künftig helfen, geschädigte HCE Zellen bereits in einem früheren Stadium zu erkennen. Neben Calcium Imaging ist die sogenannte Patch-Clamp-Technik eine wichtige Testmethode, mit der man die Wirkung verschiedenster Substanzen auf Ionenkanäle und Rezeptoren der Zellmembran überprüfen kann. Erste elektrophysiologische Pilotexperimente mit kultivierten und frisch isolierten HCE-Zellen haben vielversprechende Ergebnisse hervorgebracht. So wurde erstmals die Expression bestimmter Transient-Rezeptor-Potenzial- Kanäle (TRPs) in HCE-Zellen nachgewiesen. Die Funktion dieser TRP-Kanäle ist allerdings noch nicht völlig geklärt. Beim Menschen spielen TRP-Kanäle eine wichtige Rolle bei der Wahrnehmung von Geschmack, Pheromonen, Temperatur und Schmerz und sind an Osmolarität beteiligt. Die Übersichtsarbeit fasst den Stand der Literatur zur Elektrophysiologie des humanen Hornhautendothels zusammen und leitet daraus mögliche Ansätze zu einem empfindlichen Vitalitäts- und Funktionstest unter Ausnutzung der elektrophysiologischen Eigenschaften von HCE Zellen ab.

Abstract

Currently, the identification of apoptotic or damaged human corneal endothelial (HCE) cells is limited to a morphological assessment and vital staining. Specific electrophysiological investigations may prospectively help to identify damaged HCE cells at an earlier stage. Besides calcium imaging, the so-called patch-clamp technique is an important test method enabling one to assay the effect of various substances on ion channels and receptors of the cell membrane. First electrophysiological pilot experiments with cultivated and freshly isolated HCE cells have revealed promising results. In this way, the expression of certain transient receptor potential channels (TRPs) could be demonstrated. However, the function of these channels is still not fully elucidated. In humans, TRPs play a crucial role in the sense of taste, pheromones, temperature and pain and are involved in osmolarity. This review summarises the current literature on the electrophysiology of the human corneal endothelium and deduces potential approaches to a sensitive vitality and function test under utilisation of the electrophysiological properties of HCE cells.

Literatur

  • 1 Waring III G O, Bourne W M, Edelhauser H F et al. The corneal endothelium. Normal and pathologic structure and function.  Ophthalmology. 1982;  89 531-590
  • 2 Joyce N C. Proliferative capacity of the corneal endothelium.  Prog Retin Eye Res. 2003;  22 359-389
  • 3 Bell K D, Campbell R J, Bourne W M. Pathology of late endothelial failure: late endothelial failure of penetrating keratoplasty: study with light and electron microscopy.  Cornea. 2000;  19 40-46
  • 4 Ing J J, Ing H H, Nelson L R et al. Ten-year postoperative results of penetrating keratoplasty.  Ophthalmology. 1998;  105 1855-1865
  • 5 Bourne W M. Corneal endothelium – past, present, and future.  Eye Contact Lens. 2010;  36 310-314
  • 6 Armitage W J, Dick A D, Bourne W M. Predicting endothelial cell loss and long-term corneal graft survival.  Invest Ophthalmol Vis Sci. 2003;  44 3326-3331
  • 7 Barcia R N, Dana M R, Kazlauskas A. Corneal graft rejection is accompanied by apoptosis of the endothelium and is prevented by gene therapy with bcl-xL.  Am J Transplant. 2007;  7 2082-2089
  • 8 Fuchsluger T A, Jurkunas U, Kazlauskas A et al. Corneal Endothelial Cells Are Protected from Apoptosis by Gene Therapy.  Hum Gene Ther. 2010;  (Epub ahead of print)
  • 9 Lindstrom R L. Advances in corneal preservation.  Trans Am Ophthalmol Soc. 1990;  88 555-648
  • 10 Borenfreund E, Puerner J A. Toxicity determined in vitro by morphological alterations and neutral red absorption.  Toxicol Lett. 1985;  24 119-124
  • 11 Bednarz J, Doubilei V, Wollnik P C et al. Effect of three different media on serum free culture of donor corneas and isolated human corneal endothelial cells.  Br J Ophthalmol. 2001;  85 1416-1420
  • 12 Engelmann K, Drexler D, Böhnke M. Transplantation of adult human or porcine corneal endothelial cells onto human recipients in vitro. Part I: Cell culturing and transplantation procedure.  Cornea. 1999;  18 199-206
  • 13 Melles G R, Lander F, Rietveld F J. Transplantation of Descemet’s membrane carrying viable endothelium through a small scleral incision.  Cornea. 2002;  21 415-418
  • 14 Moller-Pedersen T, Hartmann U, Moller H J et al. Evaluation of potential organ culture media for eye banking using human donor corneas.  Br J Ophthalmol. 2001;  85 1075-1079
  • 15 Ramsey I S, Delling M, Clapham D E. An introduction to TRP channels.  Annu Rev Physiol. 2006;  68 619-647
  • 16 Rae J L, Watsky M A. Ionic channels in corneal endothelium.  Am J Physiol. 1996;  270 C975-C989
  • 17 Watsky M A, Cooper K, Rae J L. Sodium channels in ocular epithelia.  Pflugers Archive. 1991;  419 454-459
  • 18 Watsky M A, Cooper K, Rae J L. Transient outwardly rectifying potassium channel in the rabbit corneal endothelium.  J Membr Biol. 1992;  128 123-132
  • 19 Rae J L, Shepard A R. Kir2.1 Potassium channels and corneal epithelia.  Curr Eye Res. 2000;  20 144-152
  • 20 Rae J L, Dewey J, Cooper K. Properties of single potassium-selective ionic channels from the apical membrane of rabbit corneal endothelium.  Exp Eye Res. 1989;  49 591-609
  • 21 Mergler S, Dannowski H, Bednarz J et al. Calcium influx induced by activation of receptor tyrosine kinases in SV 40-transfected human corneal endothelial cells.  Exp Eye Res. 2003;  77 485-495
  • 22 Mergler S, Pleyer U, Reinach P et al. EGF suppresses hydrogen peroxide induced Ca2 + influx by inhibiting L-type channel activity in cultured human corneal endothelial cells.  Exp Eye Res. 2005;  80 285-293
  • 23 Mergler S, Pleyer U. The human corneal endothelium: New insights into electrophysiology and ion channels.  Prog Retin Eye Res. 2007;  26 359-378
  • 24 Mergler S, Valtink M, Coulson-Thomas V J et al. TRPV channels mediate temperature-sensing in human corneal endothelial cells.  Exp Eye Res. 2010;  90 758-770
  • 25 Rae J L, Dewey J, Cooper K et al. A non-selective cation channel in rabbit corneal endothelium activated by internal calcium and inhibited by internal ATP.  Exp Eye Res. 1990;  50 373-384
  • 26 Zhang F, Yang H, Wang Z et al. Transient receptor potential vanilloid 1 activation induces inflammatory cytokine release in corneal epithelium through MAPK signaling.  J Cell Physiol. 2007;  213 730-739
  • 27 Mergler S, Garreis F, Sahlmüller M et al. Thermosensitive transient receptor potential channels (thermo-TRPs) in human corneal epithelial cells.  J Cell Physiol. 2010;  ; (Epub ahead of print)
  • 28 Chuang H H, Neuhausser W M, Julius D. The super-cooling agent icilin reveals a mechanism of coincidence detection by a temperature-sensitive TRP channel.  Neuron. 2004;  43 859-869
  • 29 Voets T, Droogmans G, Wissenbach U et al. The principle of temperature-dependent gating in cold- and heat-sensitive TRP channels.  Nature. 2004;  430 748-754
  • 30 Parra A, Madrid R, Echevarria D et al. Ocular surface wetness is regulated by TRPM8-dependent cold thermoreceptors of the cornea.  Nat Med. 2010;  16 1396-1399
  • 31 Chow J, Norng M, Zhang J et al. TRPV6 mediates capsaicin-induced apoptosis in gastric cancer cells – Mechanisms behind a possible new ”hot” cancer treatment.  Biochim Biophys Acta. 2007;  1773 565-576
  • 32 Sappington R M, Sidorova T, Long D J et al. TRPV1: Contribution to Retinal Ganglion Cell Apoptosis and Increased Intracellular Ca2 + with Exposure to Hydrostatic Pressure.  Invest Ophthalmol Vis Sci. 2009;  50 717-728
  • 33 Yao X, Garland C J. Recent developments in vascular endothelial cell transient receptor potential channels.  Circ Res. 2005;  97 853-863
  • 34 Zhang W, Chu X, Tong Q et al. A novel TRPM2 isoform inhibits calcium influx and susceptibility to cell death.  J Biol Chem. 2003;  278 16222-16229
  • 35 Rusznak Z, Harasztosi C, Stanfield P R et al. An improved cell isolation technique for studying intracellular Ca(2 + ) homeostasis in neurones of the cochlear nucleus.  Brain Res Brain Res Protoc. 2001;  7 68-75
  • 36 Li Q J, Ashraf M F, Shen D F et al. The role of apoptosis in the pathogenesis of Fuchs endothelial dystrophy of the cornea.  Arch Ophthalmol. 2001;  119 1597-1604
  • 37 Lu L. Stress-induced corneal epithelial apoptosis mediated by K(+ ) channel activation.  Prog Retin Eye Res. 2006;  25 515-538
  • 38 Banan A, Fields J Z, Zhang Y et al. Key role of PKC and Ca2 + in EGF protection of microtubules and intestinal barrier against oxidants.  Am J Physiol Gastrointest Liver Physiol. 2001;  280 G828-G843
  • 39 Barisani-Asenbauer T, Kaminski S, Schuster E et al. Impact of growth factors on morphometric corneal endothelial cell parameters and cell density in culture-preserved human corneas.  Cornea. 1997;  16 537-540
  • 40 Rieck P, Oliver L, Engelmann K et al. The role of exogenous/endogenous basic fibroblast growth factor (FGF2) and transforming growth factor beta (TGF beta-1) on human corneal endothelial cells proliferation in vitro.  Exp Cell Res. 1995;  220 36-46
  • 41 Rieck P W, Gigon M, Jaroszewski J et al. Increased endothelial survival of organ-cultured corneas stored in FGF-2-supplemented serum-free medium.  Invest Ophthalmol Vis Sci. 2003;  44 3826-3832
  • 42 Mergler S, Steinhausen K, Wiederholt M et al. Altered regulation of L-type channels by protein kinase C and protein tyrosine kinases as a pathophysiologic effect in retinal degeneration.  FASEB J. 1998;  12 1125-1134
  • 43 Akanda N, Elinder F. Biophysical properties of the apoptosis-inducing plasma membrane VDAC.  Biophys J. 2006;  90 4405-4417
  • 44 Nagy P, Panyi G, Jenei A et al. Ion-channel activities regulate transmembrane signaling in thymocyte apoptosis and T-cell activation.  Immunol Lett. 1995;  44 91-95
  • 45 Parekh A B, Penner R. Store depletion and calcium influx.  Physiol Rev. 1997;  77 901-930
  • 46 Skryma R, Mariot P, Bourhis X L et al. Store depletion and store-operated Ca2 + current in human prostate cancer LNCaP cells: involvement in apoptosis.  J Physiol. 2000;  527 Pt 1 71-83
  • 47 Kruse F E, Tseng S C. Proliferative and differentiative response of corneal and limbal epithelium to extracellular calcium in serum-free clonal cultures.  J Cell Physiol. 1992;  151 347-360
  • 48 Chvatchko Y, Valera S, Aubry J P et al. The involvement of an ATP-gated ion channel, P(2X1), in thymocyte apoptosis.  Immunity. 1996;  5 275-283

Stefan Mergler

Klinik für Augenheilkunde, Charité Universitätsmedizin Berlin

Augustenburger Platz 1

13353 Berlin

Phone: ++ 49/30/55 96 48

Fax: ++ 49/30/55 99 48

Email: stefan.mergler@charite.de