Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Corneas with edema-related diseases lose transparency, which causes significant vision loss. This study analyzed seven aquaporins (AQPs) in normal corneas, pseudophakic/aphakic bullous keratopathy (PBK/ABK) corneas, Fuchs' dystrophy corneas, keratoconus corneas, post-cataract surgery (PCS) corneas, and normal organ-cultured corneas. RNA levels for AQP1, AQP4, and beta2-microglobulin were measured by RT-PCR. AQP1 antibody localized to stromal cells of all corneas. PBK/ABK and Fuchs' dystrophy corneas had decreased endothelial cell staining compared with normal. AQP1 mRNA was found in whole corneas and cultured stromal fibroblasts but not in isolated epithelial cells. AQP3 staining was found in basal epithelial cells of the normal, Fuchs' dystrophy, and keratoconus corneas but throughout the entire epithelium of PBK/ABK corneas. AQP4 antibody localized to endothelial cells of all corneas and in stromal cells of PBK/ABK corneas. AQP4 mRNA was identified in whole human corneas. AQP5 was found in epithelial cells of all corneas. AQP0, AQP2, and AQP9 were not found in any corneas. Normal AQP distributions were found in PCS and organ-cultured corneas, although they showed signs of swelling. Our study demonstrates that AQP abnormalities are found in PBK/ABK corneas (decreased AQP1, increased AQP3 and AQP4) and Fuchs' dystrophy corneas (decreased AQP1). Although both have vision-disrupting corneal edema, the mechanisms of fluid accumulation may be different in each disease.
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PMID:Altered expression of aquaporins in bullous keratopathy and Fuchs' dystrophy corneas. 1538 80

The scope of this investigation was to understand the role of aquaporin 5 (AQP5) for maintaining lens transparency and homeostasis. Studies were conducted using lenses of wild-type (WT) and AQP5 knockout (AQP5-KO) mice. Immunofluorescent staining verified AQP5 expression in WT lens sections and lack of expression in the knockout. In vivo and ex vivo, AQP5-KO lenses resembled WT lenses in morphology and transparency. Therefore, we subjected the lenses ex vivo under normal (5.6mM glucose) and hyperglycemic (55.6mM glucose) conditions to test for cataract formation. Twenty-four hours after incubation in hyperglycemic culture medium, AQP5-KO lenses showed mild opacification which was accelerated several fold at 48 h; in contrast, WT lenses remained clear even after 48 h of hyperglycemic treatment. AQP5-KO lenses displayed osmotic swelling due to increase in water content. Cellular contents began to leak into the culture medium after 48 h. We reason that water influx through glucose transporters and glucose cotransporters into the cells could mainly be responsible for creating hyperglycemic osmotic swelling; absence of AQP5 in fiber cells appears to cause lack of required water efflux, challenging cell volume regulation and adding to osmotic swelling. This study reveals that AQP5 could play a critical role in lens microcirculation for maintaining transparency and homeostasis, especially by providing protection under stressful conditions. To the best of our knowledge, this is the first report providing evidence that AQP5 facilitates maintenance of lens transparency and homeostasis by regulating osmotic swelling caused by glucose transporters and cotransporters under hyperglycemic stressful conditions.
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PMID:Aquaporin 5 knockout mouse lens develops hyperglycemic cataract. 2414 48

In this work we have analyzed the expression levels of the main aquaporins (AQPs) expressed in human lens epithelial cells (HLECs) using 112 samples from patients treated with cataract surgery and 36 samples from individuals treated with refractive surgery, with transparent lenses as controls. Aquaporin-1 (AQP1) is the main AQP, representing 64.1% of total AQPs in HLECs, with aquaporin-5 (AQP5) representing 35.9% in controls. A similar proportion of each AQP in cataract was found. Although no differences were found at the mRNA level compared to controls, a significant 1.65-fold increase (p=0.001) in AQP1protein expression was observed in HLECs from cataract patients, with the highest differences being found for nuclear cataracts (2.1-fold increase; p<0.001). A similar trend was found for AQP5 (1.47-fold increase), although the difference was not significant (p=0.161). Moreover we have shown increased membrane AQP5 protein expression in HLECs of patients with cataracts. No association of AQP1 or AQP5 expression levels with age or sex was observed in either group. Our results suggest regulation of AQP1 and AQP5 at the post-translational level and support previous observations on the implication of AQP1 and 5 in maintenance of lens transparency in animal models. Our results likely reflect a compensatory response of the crystalline lens to delay cataract formation by increasing the water removal rate.
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PMID:Increased aquaporin 1 and 5 membrane expression in the lens epithelium of cataract patients. 2749 33