A review in Hair Follicle Cycling and Glycans 2016

[Armando Jose]

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4755418/

Advances in Understanding Hair Growth


In this short review, I introduce an integrated vision of human hair follicle behavior and describe opposing influences that control hair follicle homeostasis, from morphogenesis to hair cycling. The interdependence and complementary roles of these influences allow us to propose that the hair follicle is a true paradigm of a “Yin Yangâ€￾ type, that is a cold/slow-hot/fast duality. Moreover, a new promising field is emerging, suggesting that glycans are key elements of hair follicle growth control.

 

[Swoop]

Thanks. Yes this is also what I mean by modulation of hair follicle cycling;

During the active steady state, hair fiber production results from a finely, timely, and spatially tuned choreography of gene expression, which is highly sensitive to stimulatory and inhibitory signals. A number of signaling pathways 15, cytokines 16, 17, neuropeptides 18, hormones 19– 22, prostaglandins 23, andgrowth factors 24 are known to modulate the duration of the active steady state of the hair follicle ( Figure 3)

Is modulation of hair follicle cycling really what we need though? Well in a sense yes, but really we need to revive miniaturized hair follicles due to Androgenetic Alopecia and these are clearly not as sensitive to stimulatory signals.

That's a big difference. One is easy to do the other is mission impossible pretty much.

To make an example let's take T3 in the picture here above. When can this be bad for someone? Well when someone his thyroid hormones get out of whack one can start to suffer from telogen effluvium.

Let's take another example vitamin d3 from the list. What do humans with mutations in the vitamin D receptor show? Yes that's right alopecia;

We conclude that lack of VDR causes disruption of hair follicle structure during the first catagen resulting in failure of subsequent hair follicle cycling.

ETC..

 

[Armando Jose]

You are right, but in our case the hairloss have a special pattern....., hair of sides are resistant. why?

 

[Swoop]

You are right, but in our case the hairloss have a special pattern....., hair of sides are resistant. why?

Patterning.. I don't have a answer. This hypothesis by Jahoda is interesting;

If you want to go a bit more in depth about patterning and hair formation go read this study Armando, quite interesting (also touches on Androgenetic Alopecia);

Humans differ from all other living primates in the sparseness of our hair. Even more puzzling than the overall reduction in our fur covering is the layout of the few tufts that remain. Why does hair grow mainly on our scalp , armpits, and groin? How does our genome designate these areas? Clues to the underlying mechanism can be found in mouse mutants and human syndromes, but the mystery remains essentially unsolved. This essay reviews the evidence ,pieces together the clues, and formulates a tentative hypothesis in the style of a Sherlock Holmes story. The deductive reasoning of the narrative is aided by what we already know about an analogous locus in the fruit fly that performs a comparable function.

https://www.depts.ttu.edu/biology/people/Faculty/Held/HairEvo-Devo.pdf

But it all comes down to genetics Armando.

 

[Armando Jose]

Thank you Swoop for the studies, ...., genetics, genetics, genetics. but there is not known common baldness gen, I don't understand.

IMHO scalp hair is the same in women and men, then why is different the incidence in them? BTW Hormones are made by the pilosebaceous unit, hormones running in the blood is not the reason.

A lot of questions not resolved.

Have a nice day