Document Detail


The effects of age on lens transport.
MedLine Citation:
PMID:  24065810     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: Age-related nuclear cataracts involve denaturation and aggregation of intracellular proteins. We have documented age-dependent changes in membrane transport in the mouse lens to see what might initiate changes in the intracellular milieu.
METHODS: Microelectrode-based intracellular impedance studies of intact lenses were used to determine gap junction coupling conductance, fiber and surface cell membrane conductances, effective extracellular resistivity, and intracellular voltage. Fiber cell connexin expression was detected by Western blotting. Intracellular hydrostatic pressure was measured with a microelectrode/manometer system. Concentrations of intracellular sodium and calcium were measured by intracellular injection of sodium-binding benzofuran isophthalate and Fura2, respectively.
RESULTS: In adult lenses, as age increased: fiber cell gap junction coupling conductance declined significantly, correlating with decreases in Cx46 and Cx50 labeling in Western blots; fiber and surface cell membrane conductances did not change systematically; effective extracellular resistivity increased monotonically; center to surface gradients for intracellular pressure, sodium, calcium, and voltage all increased, but in an interdependent manner that moderated changes. In newborn pup lenses, there were changes that did not simply fit with the above paradigm.
CONCLUSIONS: In newborn pup lenses, the observed changes may relate to growth factors that are not related to age-dependent changes seen in adult lenses. The major change in adult lenses was an age-dependent decrease in gap junction coupling, probably due to oxidative damage leading to degradation of connexin proteins. These changes clearly lead to compromise of intracellular homeostasis and may be a causal factor in age-related nuclear cataracts.
Authors:
Junyuan Gao; Huan Wang; Xiurong Sun; Kulandaiappan Varadaraj; Leping Li; Thomas W White; Richard T Mathias
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2013-11-01
Journal Detail:
Title:  Investigative ophthalmology & visual science     Volume:  54     ISSN:  1552-5783     ISO Abbreviation:  Invest. Ophthalmol. Vis. Sci.     Publication Date:  2013 Nov 
Date Detail:
Created Date:  2013-11-04     Completed Date:  2013-12-23     Revised Date:  2014-08-19    
Medline Journal Info:
Nlm Unique ID:  7703701     Medline TA:  Invest Ophthalmol Vis Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  7174-87     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Aging / psychology*
Animals
Biological Transport, Active
Blotting, Western
Calcium / metabolism
Cell Membrane / physiology
Connexins / metabolism
Electric Impedance
Gap Junctions / physiology
Hydrostatic Pressure
Lens, Crystalline / metabolism,  physiology*
Membrane Potentials / physiology
Mice
Mice, Inbred C57BL
Models, Biological
Sodium / metabolism
Grant Support
ID/Acronym/Agency:
EY06391/EY/NEI NIH HHS; EY13163/EY/NEI NIH HHS; EY20506/EY/NEI NIH HHS; R01 EY006391/EY/NEI NIH HHS; R01 EY013163/EY/NEI NIH HHS
Chemical
Reg. No./Substance:
0/Connexins; 9NEZ333N27/Sodium; SY7Q814VUP/Calcium
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Ocular anterior segment biometry and high-order wavefront aberrations during accommodation.
Next Document:  Imaging microscopic pigment chemistry in conjunctival melanocytic lesions using pump-probe laser mic...