Short
report on the North American Hair Research Society annual conference,
Bar Harbor, Maine, USA
The Bar Harbor conference was basic hair biology oriented so not
really directed at finding treatments for hair loss diseases. We
had reviews on gene expression and techniques for locating genes
in disease, extensive reviews on hair follicle morphology and also
comparison of hair follicles to nails and teeth as related skin
structures.
The highlights included Dr Christiano talking about the hairless
gene. This has been demonstrated not to be involved in androgenetic
alopecia. DR Christiano's team have been applying the hr mutant
gene to normal mice as a gene therapy. The application inhibited
hair growth. Although at the (very) experimental stage, DR Christiano
suggested it might be a possible gene therapy to treat excess hair
growth. DR Christiano has now identified several different forms
of hairless gene mutation in humans and several individuals previously
diagnosed as having alopecia areata were found to have a hairless
gene mutation after testing (congenital or papular atrichia).
DR Elise Olsen gave a review of androgenetic hair loss in women
and suggested that the ludwig grading system was not a good categorization
method for female pattern baldness. She suggested a more complex
categorization system based on hair parting width and the amount
of hair loss in the frontal vertex region. This system is to be
published shortly.
Of interest to me was an announcement during the conference that
a grant application to the National Institute of Arthritis and Musculoskeletal
and Skin Diseases (NIAMS) to set up a central DNA repository for
alopecia areata research had been awarded. The will involve funding
worth $2.7 million over a 5 year period. The following are the sites
of the registry; University of Texas, Houston, University of Colorado
Health Sciences Center, Denver Columbia University, New York, New
York, University of Minnesota, Minneapolis, and University of California,
San Francisco.
Genes and gene therapy was a big focus at the conference. Several
seminars discussed gene expression during the hair cycle and showed
that several wnt genes and the Noggin gene are fundamentally involved
in hair cycling and growth. Gene therapy reviewed by Lorne Taichman
showed that in principle it is possible to transfect hair follicle
cells with genes and have gene expression persist for at least 16
weeks. His team transfected a lacZ reporter gene into mouse hair
follicles and the gene activity was still present, albeit in a patchy
manner, 16 weeks later. They are confident they had transfected
hair follicle stem cells given the expression lasted so long.
Maybe of most interest to you would have been the talk by Keith
Kaufman from Merck. He gave the typical review of Propecia, but
a few slides he flashed up were new to me. The most recent results
on Propecia show that the individuals who have been using for 5
years now are starting to have a decline in the hair density. Before
the hair density had always gradually climbed year on year and the
placebo users had progressively declined. However, both groups at
year 5 had a drop in hair density although the Propecia users still
have much more hair than the placebo users.
The typical anagen growth phase for scalp hair last 4-5 years.
So it was suggested that the decline was because the hair follicles,
under the control of Propecia, were entering a telogen phase at
about the same time. Hair follicles cycle in a random mosaic pattern
in humans but the cycle can be coordinated under the control of
drugs like minoxidil and Propecia. I guess Merck will be hoping
the hair density will bounce up again with next years results.
Merck very briefly discussed new treatments from themselves and
Glaxo. Merck suggested there might be some dangers in using a type
I and II 5 alpha reductase inhibitor such as Glaxo's Dutasteride
and Turosteride drugs. The 5 alpha reductase inhibitors would lead
to a significant
increase in testosterone and this could be transformed into estrogens
by other enzymes in the body. Consequently, it was suggested that
there could be an increased potential risk of estrogen disorders
in Dutasteride users. Kaufman also briefly flashed up a slide on
other potential drugs for androgenetic alopecia including "melformin"
and "thiazolidinediones"
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