Re-Visiting a Post by Lou Pagnucco

Lou Pagnucco pagnucco at
Sat Oct 24 23:07:47 EST 1998

James <james at> wrote in article <3630B0B0.5C76A03E at>...
> > A weaker link in Lou's idea is the question of whether these senescent
> > fibroblasts are responsible for lax skin etc.  It is unclear whether
> > the overproduction of collagenase would have these effects, since they
> > are normally ascribed to the disorderly crosslinking of OLD collagen.
> > Most such collagen should be no less degradable by collagenase than
> > undamaged collagen, so this overproduction may, if anything, actually
> > RETARD these features of aging of skin.
> I would agree with this 100% - if collagenase were the only
> factor.  But I don't think lax skin has much to do with collagen
> crosslinking (other than some decreased elasticity).  I think
> loss of subcutaneous fat is the culprit here.  I don't know why
> that happens - is it a general hormonal change, or something to
> do with fibroblasts?

But don't the cells that adhere to the extracellular matrix
obtain much of their regulatory signals from the ECM?
Isn't this a "chicken first or egg first" question?

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