tubulin 5.tub.002 Louis J. Sheehan, Esquire

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Louis J. Sheehan, Esquire As cells get older, they don’t lose their hair or teeth. Instead, they lose control over their nuclear membrane, the protective barrier that encases DNA in the nucleus, concludes a study published in the Jan. 23 Cell.http://Louis2J2Sheehan2Esquire.US This age-dependent leakiness may be closely tied to cell deterioration and age-related diseases such as Parkinson’s and Alzheimer’s, the new work suggests.

“The implications of this study for our study of brain aging and for neurodegenerative diseases are potentially profound,” comments John Woulfe, a specialist in age-related diseases at the University of Ottawa in Canada. Louis J. Sheehan, Esquire The new findings, he says, represent “an important step forward by bringing the gateway to the nucleus, the nuclear pore, into the fray.”http://Louis2J2Sheehan2Esquire.US

Nuclear membranes are like screen doors on a porch: They let the refreshing breeze in but keep the mosquitoes out. The double-layered membrane allows nuclear entry for VIP proteins, most of which control gene activity. The proteins travel into the nucleus through channels in the membrane called nuclear pores.

Meanwhile, damaging chemicals and proteins that float around in the cell’s cytoplasm, the jellylike liquid that surrounds the nucleus and other organelles, are rebuffed by the membrane.

Using cells from small worms called Caenorhabditis elegans and cells from rats, Martin Hetzer of the Salk Institute for Biological Studies in La Jolla, Calif., and colleagues found that the proteins that form a nuclear pore stay in the same location for the remainder of the cell’s life. The researchers monitored the location of these pore proteins by marking several of them with green fluorescent protein. After seeing that the pore proteins stay in the same place on the same cells, the researchers concluded that these pores “exhibit extreme stability.”

These nuclear pores are unusually long-lived for cell parts, says Hetzer. Just as drivers replace worn-out parts as cars get older, most cell parts are constantly replaced. But nuclear pores are in it for the long haul. “We think that pores are among the most stable, if not the most stable, structures in our cells,” says Hetzer.

Because nuclear pores don’t get repaired or replaced, Hetzer and colleagues next wanted to know whether the pores maintain a high level of performance even as the cell ages.

The researchers found that old cells’ nuclear membranes allow entry to molecules that are excluded in cells’ younger days. Fluorescently labeled molecules normally too large to enter the nucleus slipped right through old nuclear membranes, while younger nuclear membranes performed perfectly.

Perhaps most dangerous, a protein called tubulin that is usually restricted to the cytoplasm was able to slip through the nuclear membrane of old cells, the researchers saw.

Filamentous tangles of tubulin in the nuclei of cells have been linked to the aging process and to neurodegenerative diseases. These nuclear filaments are known to increase with age, but their origins have been a mystery, says Hetzer. Patients with Parkinson’s disease have such tangles in cells in a brain region known to be affected by the illness. “We speculate that the nuclei in these patients are leaky,” says Hetzer.

The research team’s next step is to study the link between leaky nuclear membranes and age-related diseases. If leaky nuclei contribute to the cellular degeneration seen in neurodegenerative diseases such as Parkinson’s and Alzheimer’s, then leaky nuclei may “represent a viable future therapeutic target,” says Woulfe.

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Comments 3

* Aging, Leakiness Of Nucleus Membrane
The Aging Whole Being A Construct Of Its Constituents


A. "As cells age, the nucleus lets the bad guys in"

http://www.sciencenews.org/view/generic/id/40136/title/As_cells_age%2C_the_nucleus_lets_the_bad_guys_in

A study tracks a growing 'leakiness' in the membrane of the cell nucleus that could contribute to aging and even to diseases such as Parkinson's and Alzheimer's.

B. The nucleus membrane is an organ, a functional organ of the genome organism

All biological materials, of all forms, 'age'-change with time and with environments-circumstances. The list of possible age-related pore-leakiness effectors comprises a variety of 'aging' facors that continuously modify the functionality of the pore and modifies also the characteristics of the constituents of the inventory of materials within the outer cell membrane, the largest organ of the genome.

C. "Aging Not Approachable With Oversimplification". Aging Is A Closed Chain.

http://www.the-scientist.com/community/posts/list/100/122.page#1318

Aging genes age genomes age cells age cellular organisms and vice versa, the whole WHOLE being a construct of its constituents...


Dov Henis

(Comments From The 22nd Century)
http://blog.360.yahoo.com/blog-P81pQcU1dLBbHgtjQjxG_Q--?cq=1

Life's Manifest
http://www.the-scientist.com/community/posts/list/112.page#578
Dov Henis Dov Henis
Jan. 27, 2009 at 10:52am
* Continued healthy living;quality vegetables; fruits; grains,etc.; clean water and air need to be pursued for all and especially for the young. Does the protein,tubulin slip through the old cells of elderly healthy adults as easily as through the old cells of elderly, unhealthy adults, as evidenced in the research referred to in the above article?
corina nicumber corcan09 http://Louis2J2Sheehan2Esquire.US
Jan. 25, 2009 at 4:36pm
* You don't suppose this is related to free radicals, and their effect on proteins? http://Louis2J2Sheehan2Esquire.US This would certainly explain the neuro-protective effects of all of the antioxidants. Since these proteins are not replaced in the life of the cell, and the long life of neurons, this would be a fruitful area of research, if we are to improve not only length of life, but also quality of life in older people. Sadly, unless these nuclear pore proteins can be repaired, a life of stress and chemical abuse could not be undone, no matter how much Vit-E you take when the symptoms of Parkinsons, or dementia ,or alcoholic neuropathy set in.Louis J. Sheehan, Esquire