The Expression of Rab8, Ezrin, Radixin and Moesin in the Ciliary Body of Cynomolgus Monkeys

Overview

Journal Juntendo Iji Zasshi

Specialty General Medicine

Date 2024 Jul 18

PMID 39021423

Authors

Kazuhiko Tanabe

Itaru Kimura

Haru Okamoto

Zai-Long Chi

Masakazu Akahori

Nobuhiro Shimozawa

Nobuyuki Ebihara

Akira Murakami

Takeshi Iwata

Affiliations

Soon will be listed here.

Abstract

Purpose: The purpose of this study was to determine what proteins are present in the ciliary body (CB). To accomplish this, we conducted a proteomic analysis of the CB of cynomolgus monkeys. We also determined the location of the proteins in CB by immunohistology.

Methods: The eyes of euthanized cynomolgus monkeys were enucleated, and the CB, were isolated from the eyes. Proteins were extracted from the CB and determined by liquid chromatography-mass spectrometry. Separated CB epithelial cells were cultured, and the proteins expressed in the CB were determined by Western blotting. The location of these proteins in the CB was determined by immunohistochemical staining. We also investigated whether adding dexamethasone to the culture medium changed protein expression by the epithelial cells.

Results: Proteomic analysis of the CBs showed that 813 proteins were expressed in the epithelium and stroma. These proteins included the small guanosine triphosphate-binding protein Rab8 and the ezrin/radixin/moesin (ERM) family. Tissue and immunohistological staining confirmed the colocalization of these proteins in non-pigmented CB epithelium. Western blotting of cultured CB epithelial cell lysates showed a tendency that adding dexamethasone changed Rab8 protein expression levels.

Conclusions: Proteomic analysis of CBs identified several proteins involved in the transport and secretion of proteins. These proteins may be involved in the production of aqueous humor and protein secretion by the CB.

References

Kwon Y, Fingert J, Kuehn M, Alward W . Primary open-angle glaucoma. N Engl J Med. 2009; 360(11):1113-24. PMC: 3700399. DOI: 10.1056/NEJMra0804630. View

Quigley H . Glaucoma. Lancet. 2011; 377(9774):1367-77. DOI: 10.1016/S0140-6736(10)61423-7. View

Wordinger R, Clark A . Effects of glucocorticoids on the trabecular meshwork: towards a better understanding of glaucoma. Prog Retin Eye Res. 1999; 18(5):629-67. DOI: 10.1016/s1350-9462(98)00035-4. View

Vadillo-Ortega F, Gonzalez-Avila G, Chevez P, Abraham C, Montano M . A latent collagenase in human aqueous humor. Invest Ophthalmol Vis Sci. 1989; 30(2):332-5. View

Sato T, Mushiake S, Kato Y, Sato K, Sato M, Takeda N . The Rab8 GTPase regulates apical protein localization in intestinal cells. Nature. 2007; 448(7151):366-9. DOI: 10.1038/nature05929. View

Yonemura S, Tsukita S . Direct involvement of ezrin/radixin/moesin (ERM)-binding membrane proteins in the organization of microvilli in collaboration with activated ERM proteins. J Cell Biol. 1999; 145(7):1497-509. PMC: 2133160. DOI: 10.1083/jcb.145.7.1497. View

Haddad A, Laicine E, Almeida J . Origin and renewal of the intrinsic glycoproteins of the aqueous humor. Graefes Arch Clin Exp Ophthalmol. 1991; 229(4):371-9. DOI: 10.1007/BF00170697. View

Quigley H, Broman A . The number of people with glaucoma worldwide in 2010 and 2020. Br J Ophthalmol. 2006; 90(3):262-7. PMC: 1856963. DOI: 10.1136/bjo.2005.081224. View

Wilson K, McCartney M, Miggans S, Clark A . Dexamethasone induced ultrastructural changes in cultured human trabecular meshwork cells. Curr Eye Res. 1993; 12(9):783-93. DOI: 10.3109/02713689309020383. View

10.

Chi Z, Akahori M, Obazawa M, Minami M, Noda T, Nakaya N . Overexpression of optineurin E50K disrupts Rab8 interaction and leads to a progressive retinal degeneration in mice. Hum Mol Genet. 2010; 19(13):2606-15. PMC: 2883340. DOI: 10.1093/hmg/ddq146. View

11.

Clark A, Steely H, Dickerson Jr J, Stropki K, McCartney M, Jacobson N . Glucocorticoid induction of the glaucoma gene MYOC in human and monkey trabecular meshwork cells and tissues. Invest Ophthalmol Vis Sci. 2001; 42(8):1769-80. View

12.

Deretic D, Traverso V, Parkins N, Jackson F, Rodriguez de Turco E, Ransom N . Phosphoinositides, ezrin/moesin, and rac1 regulate fusion of rhodopsin transport carriers in retinal photoreceptors. Mol Biol Cell. 2003; 15(1):359-70. PMC: 307553. DOI: 10.1091/mbc.e03-04-0203. View

13.

Crabb J, Miyagi M, Gu X, Shadrach K, West K, Sakaguchi H . Drusen proteome analysis: an approach to the etiology of age-related macular degeneration. Proc Natl Acad Sci U S A. 2002; 99(23):14682-7. PMC: 137479. DOI: 10.1073/pnas.222551899. View

14.

Coca-Prados M, Escribano J . New perspectives in aqueous humor secretion and in glaucoma: the ciliary body as a multifunctional neuroendocrine gland. Prog Retin Eye Res. 2007; 26(3):239-62. DOI: 10.1016/j.preteyeres.2007.01.002. View

15.

Fautsch M, Howell K, Vrabel A, Charlesworth M, Muddiman D, Johnson D . Primary trabecular meshwork cells incubated in human aqueous humor differ from cells incubated in serum supplements. Invest Ophthalmol Vis Sci. 2005; 46(8):2848-56. DOI: 10.1167/iovs.05-0101. View

16.

Rozsa F, Reed D, Scott K, Pawar H, Moroi S, Kijek T . Gene expression profile of human trabecular meshwork cells in response to long-term dexamethasone exposure. Mol Vis. 2006; 12:125-41. View

17.

To C, Kong C, Chan C, Shahidullah M, Do C . The mechanism of aqueous humour formation. Clin Exp Optom. 2002; 85(6):335-49. View

18.

Garcia-Ramirez M, Canals F, Hernandez C, Colome N, Ferrer C, Carrasco E . Proteomic analysis of human vitreous fluid by fluorescence-based difference gel electrophoresis (DIGE): a new strategy for identifying potential candidates in the pathogenesis of proliferative diabetic retinopathy. Diabetologia. 2007; 50(6):1294-303. DOI: 10.1007/s00125-007-0627-y. View

19.

Delamere N . Ciliary Body and Ciliary Epithelium. Adv Organ Biol. 2011; 10:127-148. PMC: 3018825. DOI: 10.1016/S1569-2590(05)10005-6. View

20.

Shibuya M, Okamoto H, Nozawa T, Utsumi J, Reddy V, Echizen H . Proteomic and transcriptomic analyses of retinal pigment epithelial cells exposed to REF-1/TFPI-2. Invest Ophthalmol Vis Sci. 2007; 48(2):516-21. DOI: 10.1167/iovs.06-0434. View