Ultraviolet B preconditioning enhances the hair growth-promoting effects of adipose-derived stem cells via generation of reactive oxygen species.

Stem Cells Dev. 2012 Jul 11. [Epub ahead of print]
Ultraviolet B preconditioning enhances the hair growth-promoting effects of adipose-derived stem cells via generation of reactive oxygen species.
Jeong YM, Sung YK, Kim WG, Kim JH, Kwack MH, Yoon IS, Kim DD, Sung JH.

CHA Univ, Seoul, Korea, Republic of; freshcell@wm.cau.ac.kr.

Hypoxia induces the survival and regenerative potential of adipose-derived stem cells (ASCs), but there are tremendous needs to find alternative methods for ASC preconditioning. Therefore, this work investigated: 1) the ability of low-dose ultraviolet B (UVB) radiation to stimulate the survival, migration and tube-forming activity of ASCs in vitro; 2) the ability of UVB preconditioning to enhance the hair growth-promoting capacity of ASCs in vivo; and 3) the mechanism of action for ASC stimulation by UVB. Although high-dose UVB decreased the proliferation of ASCs, low-dose (10 or 20 mJ/cm2) treatment increased their survival, migration and tube-forming activity. In addition, low-dose UVB up-regulated the expression of ASC-derived growth factors, and culture medium conditioned by UVB-irradiated ASCs increased the proliferation of dermal papilla (DP) and outer root sheet (ORS) cells. Notably, injection of UVB-preconditioned ASCs into C3H/HeN mice significantly induced the telogen-to-anagen transition and increased new hair weight in vivo. UVB treatment significantly increased the generation of reactive oxygen species (ROS) in cultured ASCs, and inhibition of ROS generation by diphenyleneiodonium chloride (DPI) significantly attenuated UVB-induced ASC stimulation. Furthermore, NADPH oxidase 4 (Nox4) expression was induced in ASCs by UVB irradiation, and Nox4 silencing by small interfering RNA, like DPI, significantly reduced UVB-induced ROS generation. These results suggest that the primary involvement of ROS generation in UVB-mediated ASC stimulation occurs via the Nox4 enzyme. This is the first indication that a low dose of UVB radiation and/or the control of ROS generation could potentially be incorporated into a novel ASC preconditioning method for hair regeneration.

Hormesis.

I wonder if this is related to our endogenous antioxidant systems, at least in principle. There was a thread posted here not too long ago featuring Dr. Chris Shade (https://immortalhair.forumotion.com/t7412-dr-chris-shade-about-mercury-detox?highlight=mercury) where he discussed that our endogenous antioxidant systems are bolstered by certain plant extracts due to minor ROS generation by those phytochemicals. It seems like a "controlled burn", per se, has a strong adaptive rxn on the body. This principle seems to permeate into other things as well, including exercise. Just examples of how moderate inflammation has a beneficial effect. Might also relate to the evidence presented here on the forum on how injury stimulated hair growth.

Since it was ultraviolet B used, I first thought the vitamin D factor, however from there it still requires 2 hydroxylations for activation (liver and in the kidney).

Perhaps it is hormesis