Question

Which substance found in the eye is not uveitogenic? a. S-antigen (arrestin) b. TGF- \(\beta\) c. interphotoreceptor retinoid-binding protein (IRBP) d. recoverin e. phosduscin

Short answer

a. S-antigen (arrestin) b. TGF-beta c. Interphotoreceptor retinoid-binding protein (IRBP) d. Recoverin e. Phosducin Answer: e. Phosducin

Step-by-step solution

Identify and research the given substances in eyes

In order to identify which substance is not uveitogenic, familiarity with each substance and its relation to the eye and eye inflammation is essential. Perform a quick research to gather this information.

Determine the properties of each substance related to uveitis

Based on your research, determine whether each substance is uveitogenic or not, focusing especially on their role in uveitis or possible inflammatory properties. a. S-antigen (arrestin): This protein is present in photoreceptor cells and is involved in the phototransduction cascade, and it has been linked to the pathogenesis of experimental autoimmune uveoretinitis (EAU), an animal model of human uveitis. b. \(\mathrm{TGF}-\beta\): Transforming growth factor-beta (TGF-beta) is involved in cellular processes such as differentiation, proliferation, and wound healing. It has been found to play a role in inflammation and fibrosis, which suggests that it is uveitogenic. c. Interphotoreceptor retinoid-binding protein (IRBP): This protein is found in the extracellular matrix of the retina. Like arrestin, IRBP has been reported to induce experimental autoimmune uveoretinitis (EAU). d. Recoverin: This is another protein found in photoreceptor cells, involved in the phototransduction process. It has been reported to cause cancer-associated retinopathy (CAR), which can lead to uveitis. e. Phosducin: This protein regulates the phototransduction cascade in photoreceptor cells. It has not been associated with uveitis and does not have any known pro-inflammatory properties.

Choose the substance that is not uveitogenic

Based on your analysis in Step 2, you can identify the substance that is not uveitogenic. For this question, the answer is e. Phosducin, as it does not have any known associations with uveitis or inflammation.