Extrinsic and Intrinsic Factors Determine Expression Levels of Gap Junction-Forming Connexins in the Mammalian Retina

Tamás Kovács-Öller; Gergely Szarka; Gyula Hoffmann; Loretta Péntek; Gréta Valentin; Liliana Ross; Béla Völgyi

doi:10.3390/biom13071119

Extrinsic and Intrinsic Factors Determine Expression Levels of Gap Junction-Forming Connexins in the Mammalian Retina

Biomolecules. 2023 Jul 13;13(7):1119. doi: 10.3390/biom13071119.

Authors

Tamás Kovács-Öller^{1

2

3

4}, Gergely Szarka^{1

2

3

4}, Gyula Hoffmann^{1

2

3

4}, Loretta Péntek^{1

2}, Gréta Valentin^{1

2}, Liliana Ross⁵, Béla Völgyi^{1

2

3

4}

Affiliations

¹ Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary.
² Department of Neurobiology, University of Pécs, 7624 Pécs, Hungary.
³ NEURON-066 Rethealthsi Research Group, 7624 Pécs, Hungary.
⁴ Center for Neuroscience, University of Pécs, 7624 Pécs, Hungary.
⁵ Faculty of Science, University of Calgary, Calgary, AB T2N 1N4, Canada.

Abstract

Gap junctions (GJs) are not static bridges; instead, GJs as well as the molecular building block connexin (Cx) proteins undergo major expression changes in the degenerating retinal tissue. Various progressive diseases, including retinitis pigmentosa, glaucoma, age-related retinal degeneration, etc., affect neurons of the retina and thus their neuronal connections endure irreversible changes as well. Although Cx expression changes might be the hallmarks of tissue deterioration, GJs are not static bridges and as such they undergo adaptive changes even in healthy tissue to respond to the ever-changing environment. It is, therefore, imperative to determine these latter adaptive changes in GJ functionality as well as in their morphology and Cx makeup to identify and distinguish them from alterations following tissue deterioration. In this review, we summarize GJ alterations that take place in healthy retinal tissue and occur on three different time scales: throughout the entire lifespan, during daily changes and as a result of quick changes of light adaptation.

Keywords: circadian rhythm; connexin; development; gap junction; light adaptation; retina.

Publication types

Review
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Connexins* / genetics
Connexins* / metabolism
Gap Junctions* / metabolism
Mammals / metabolism
Neurons / metabolism
Retina / metabolism

Substances

Connexins

Grants and funding

This study was supported by the NKFIH and the European Union under the action of the ERA-NET COFUND (2019-2.1.7-ERANET-2021–00018; NEURON (NEURON-066 Rethealthsi) to B.V. The study was also financially supported by the NKFI (OTKA NN128293) (B.V.) from the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TKP2020 IKA-07 National Excellence Program (BV, T.K.-Ö.). In addition, this research was also financed by the Thematic Excellence Program 2021 Health Sub-programme of the Ministry for Innovation and Technology in Hungary, within the framework of the EGA-16 project of the University of Pécs. Finally, this work was supported by the ÚNKP-22-3-II-PTE-1414 (G.S.) New National Excellence Program of the Ministry of Human Capacities.