Modulation of Rac1/PAK1/connexin43-mediated ATP release from astrocytes contributes to retinal ganglion cell survival in experimental glaucoma

© 2023 Wiley Periodicals LLC..

Connexin43 (Cx43) is a major gap junction protein in glial cells. Mutations have been found in the gap-junction alpha 1 gene encoding Cx43 in glaucomatous human retinas, suggestive of the involvement of Cx43 in the pathogenesis of glaucoma. However, how Cx43 is involved in glaucoma is still unknown. We showed that increased intraocular pressure in a glaucoma mouse model of chronic ocular hypertension (COH) downregulated Cx43, which was mainly expressed in retinal astrocytes. Astrocytes in the optic nerve head where they gather and wrap the axons (optic nerve) of retinal ganglion cells (RGCs) were activated earlier than neurons in COH retinas and the alterations in astrocytes plasticity in the optic nerve caused a reduction in Cx43 expression. A time course showed that reductions of Cx43 expression were correlated with the activation of Rac1, a member of the Rho family. Co-immunoprecipitation assays showed that active Rac1, or the downstream signaling effector PAK1, negatively regulated Cx43 expression, Cx43 hemichannel opening and astrocyte activation. Pharmacological inhibition of Rac1 stimulated Cx43 hemichannel opening and ATP release, and astrocytes were identified to be one of the main sources of ATP. Furthermore, conditional knockout of Rac1 in astrocytes enhanced Cx43 expression and ATP release, and promoted RGC survival by upregulating the adenosine A3 receptor in RGCs. Our study provides new insight into the relationship between Cx43 and glaucoma, and suggests that regulating the interaction between astrocytes and RGCs via the Rac1/PAK1/Cx43/ATP pathway may be used as part of a therapeutic strategy for managing glaucoma.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:71

Enthalten in:

Glia - 71(2023), 6 vom: 28. Juni, Seite 1502-1521

Sprache:

Englisch

Beteiligte Personen:

Zhao, Guo-Li [VerfasserIn]
Zhou, Hong [VerfasserIn]
Guo, Yun-Hui [VerfasserIn]
Zhong, Shu-Min [VerfasserIn]
Zhou, Han [VerfasserIn]
Li, Fang [VerfasserIn]
Lei, Bo [VerfasserIn]
Wang, Zhongfeng [VerfasserIn]
Miao, Yanying [VerfasserIn]

Links:

Volltext

Themen:

8L70Q75FXE
ATP
Adenosine Triphosphate
Astrocyte
Connexin 43
Connexin43
EC 2.7.11.1
EC 3.6.5.2
Glaucoma
Journal Article
P21-Activated Kinases
PAK1 protein, human
RAC1 protein, human
Rac1
Rac1 GTP-Binding Protein
Research Support, Non-U.S. Gov't
Retina

Anmerkungen:

Date Completed 06.04.2023

Date Revised 11.04.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/glia.24354

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM353010537