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

Stem Cells Dev. 2013 Jan 1;22(1):158-68. doi: 10.1089/scd.2012.0167. Epub 2012 Aug 13.
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 WK, Kim JH, Kwack MH, Yoon I, Kim DD, Sung JH.

Department of Applied Bioscience, CHA University, Seoul, Korea.

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/cm(2)) treatment increased their survival, migration, and tube-forming activity. In addition, low-dose UVB upregulated the expression of ASC-derived growth factors, and a culture medium conditioned by UVB-irradiated ASCs increased the proliferation of dermal papilla and outer root sheet cells. Notably, injection of UVB-preconditioned ASCs into C(3)H/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.

Exp Dermatol. 2012 Nov;21(11):827-30. doi: 10.1111/exd.12001.
Unravelling hair follicle-adipocyte communication.
Schmidt B, Horsley V.

Department of Molecular, Cell and Developmental Biology, Yale Stem Cell Center, Yale University, New Haven, CT, USA.

Here, we explore the established and potential roles for intradermal adipose tissue in communication with hair follicle biology. The hair follicle delves deep into the rich dermal macroenvironment as it grows to maturity where it is surrounded by large lipid-filled adipocytes. Intradermal adipocytes regenerate with faster kinetics than other adipose tissue depots and in parallel with the hair cycle, suggesting an interplay exists between hair follicle cells and adipocytes. While adipocytes have well-established roles in metabolism and energy storage, until recently, they were overlooked as niche cells that provide important growth signals to neighbouring skin cells. We discuss recent data supporting adipocytes as niche cells for the skin and skin pathologies that may be related to alterations in skin adipose tissue defects.

Wound Repair Regen. 2013 Aug 12. doi: 10.1111/wrr.12080. [Epub ahead of print]
Adipose tissue-derived stem cells (ADSCs) transplantation promotes regeneration of expanded skin using a tissue expansion model.
Sheng L, Yang M, Liang Y, Li Q.

Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Transplantation of adipose tissue-derived stem cells (ADSCs) is a promising method that has been used in regenerative medicine because it has shown the capacity to accelerate wound healing. However, roles of ADSCs transplantation in expanded-skin regeneration have remained unknown. To clarify the roles, a tissue expansion model was used in this study. The study comprised three groups of 13 rats in each group: the ADSCs group, the fibroblast (FB) group, and the control group. The skin regeneration in the ADSCs group was enhanced, as evidenced by increased cell proliferation and a higher hydroxyproline content and degree of neovascularization, all with p < 0.05, when compared with both the FB group and the control group. Consistent with enhanced cell proliferation and neovascularization, the regenerated skin in the ADSCs group was much thicker, which further reduced the retraction ratio of the expanded skin. Four weeks after operation, 5'-bromo-2'-deoxyuridine-labeled ADSCs appeared in subcutaneous tissue, vascular vessels, and hair follicles. The up-regulation of protein expression, such as epidermal growth factor and vascular endothelial growth factor, primarily emerged in the ADSC group, with the up-regulated basic fibroblast growth factor appearing in the FB group. Collectively, these results suggest that the transplantation of ADSCs could enhance the regeneration of expanded skin by participating in skin structures and up-regulating the secretion of epidermal growth factor and vascular endothelial growth factor.

https://www.jstage.jst.go.jp/article/biomedres/31/1/31_1_27/_article