Aqueous humor myocilin protein levels in normal, genetic carriers, and glaucoma Beagles

Abstract

This study shows myocilin protein is present in normal Beagles, markedly increased in POAG Beagles, and mildly increased in genetic carrier Beagles. There is a strong correlation between amounts of AH myocilin protein and the presence and severity of POAG. The exact role of AH myocilin levels in the genesis of ocular hypertension remains unresolved, but myocilin may adversely affect AH outflow.

Definition, Classification, and Pathophysiology of Canine Glaucoma

“…152 These responses may lead to pathologically important changes when the pressure stress is high, with age, or with genetic variations in the translation of proteins involved with ECM modifications. [153][154][155][156][157] In glaucomatous human patients the blood-aqueous barrier is often disrupted and the quality of the proteins and cytokines present varies from that expressed in normal aqueous. 158 In the author's opinion, immunologic mechanisms are also involved in the outflow obstruction in dogs, and the role of mononuclear cells, particularly macrophages, is crucial.…”

Myocilin Levels in Primary Open-angle Glaucoma and Pseudoexfoliation Glaucoma Human Aqueous Humor

“…Evidence supports a role for elevated myocilin levels in canine glaucomatous aqueous humor particularly in breeds with primary glaucoma 22. Beagles genetically susceptible to formation of glaucoma had increased levels of myocilin in their aqueous humor in a direct relation to the severity of the disease 23. Less well understood is the relationship of myocilin levels in human glaucomatous aqueous humor, particularly in POAG and PEXG.…”

Genetics of Canine Primary Glaucomas

“…[31][32][33][34] To date, no MYOC mutations have been identified in dogs. 18,19 MYOC protein concentrations were shown to be elevated in the aqueous humor of several canine breeds with primary glaucoma, 35,36 but the function of MYOC and its role in the molecular disease process resulting in increased IOP remain unknown.…”

“…Other prominent human glaucoma genes include OPTN (optineurin), 37 cytochrome P450 1B1 (CYP1B1), 38 NTF4 (neurotrophin 4), 39,40 TBK1 (TANK-binding kinase 1), 41,42 and WDR36 (WD repeat domain 36). 43 In addition to these specific glaucoma genes, large-scale GWAS have led to the identification of genetic loci that contribute to the development of POAG [44][45][46][47][48][49][50] and PACG.…”