So it is time to discuss Team Tokyo in a special thread. Some of this has been taken from hairsite, but all the neccessary information can be found on the links I provided.
Of particular note is this:
Reporting in Nature Communications the group demonstrate that bioengineered hair follicle germ reconstructed from adult epithelial stem cells and dermal papilla cells can regenerate fully functional hair follicle and hair growth. Their bioengineered follicles showed restored hair cycles and piloerection through the rearrangement of follicular stem cells and their niches. The bioengineered hair follicle also developed the correct structures and formed proper connections with surrounding host tissues such as the epidermis, arrector pili muscle and nerve fibers.
The bold part actually shows us the ability of stem cells which can grow hair on their own when transplanetd. There was no need to transplant surrounding tissue, and this is great. The new hair follicels managed to connect with arrector pili muscle, epidermis and even nerve fibers!
Also note that the hair follicels used had dermal papilla cells
which are being used by Aderans. However, DP cells had the help from adult epithelial stem cells
. I believe this is the reason why Replicel had such bad results. Dermal sheath cup cells need the help, something to guide them to connect to the surrounding tisue (epidermis, nerve fibbers, arrector pili muscle).
Now nerve fibers themselves are of importance in hair growth. The following excerpt has been taken from: Stress and the Hair Follicle: Exploring the
Connections, Vladimir A. Botchkarev, found at:
The hair follicle bulge region contains a population of putative hair follicle stem cells. A close localization of sensory and autonomic nerve fibers and hair follicle bulge raises a possibility that neuropeptides and neurotransmitters may influence stem cells or their progeny and modulate hair cycle. Indeed, bulge keratinocytes show expression of
2-adrenoreceptors and neurokinin-1 receptor (Botchkarev et al, unpublished observations). Treatment of telogen mice by substance P or by noradrenaline- depleting agents lead to stimulation of hair growth, whereas substance P administration into anagen skin results in premature catagen development. Recent data suggest that denervation of murine skin leads to down-regulation of expression of hair keratin genes. Taken together, these data suggest that neurohormones, neuropeptides, and neurotransmitters may significantly influence cyclic activity of the hair follicle further supporting the hypothesis that hair follicles represent an important target for stressors.
As we can see regardless of stress, nerve fibers also play a role together with arrector pili muscle and epidermis and other tissues. Now it seems to me that what Replicel and Aderans are missing in all of these is adult epithelial stem cells
. Which can be isolated.
It is viable: http://www.ncbi.nlm.nih.gov/pubmed/21490579
Ofcourse the question is which adult stem cells, and then how to combine them with DP or DSC cells. Although I am cheering for DP cells.
I am a layman and I might be wrong at some things, but this is how I understood it.
In the end some bad news
: so far no human trials have been announced.
But atleast it shows us that Dermal papilla cells might work, and those rumors of moderate growth from Aderans seem more plausible now.
If anyone has any news or more detailed information please post. Ofcourse I welcome all opinions and criticism.
EDIT: Also note that when I am talking about Aderans and Replicel I am saying of somehow combining the adult epithelial stem cells with dermal papilla cells, but the researchers at Tsuji-lab have actually bioengineered a hair follicle which is different and I believe more complex, and Aderans and Replicel can't do that yet, however just combining the above mentioned cells might be benefical for regrowth.