Carbon Dioxide Fractional Laser Treatment Induces Lgr5+ Stem Cell Activation and Hair Regrowth Through the Canonical Wnt/ß-Catenin Pathway.

BACKGROUND: Different types of alopecia have negative impacts on patients. Recently, some kinds of laser or light therapies have been reported to effectively alleviate hair loss. Carbon dioxide fractional laser (CO2FL) treatment is one of the most effective laser treatments, but its beneficial effects and exact mechanism in hair regrowth have not been reported in detail. The purpose of this study was to investigate the effect and molecular mechanism further. METHODS: C57 and Lgr5-Cre: Rosa-mTmG mouse models of hair regrowth were established by CO2FL treatment, and the parameters that induced the best effect were determined. Tissues were harvested on the day prior to the treatment day and on days 3, 5, 7, 10 and 14 after CO2FL. H&E and immunofluorescence staining, RNA sequencing (RNA-seq), quantitative real-time polymerase chain reaction (qPCR), Western blotting (WB) and related inhibitor were used to determine the molecular mechanism underlying the effect of CO2FL treatment on the hair cycle and hair regrowth. In clinical trial, five participants were treated three sessions at 1-month intervals to obverse the effects. RESULTS: Hair regrew and covered the treatment area on the tenth day after CO2FL treatment with the best parameters, while the control group showed signs of hair growth on the 14th day. H&E and immunofluorescence staining showed that the transition of hair follicles (HFs) from telogen to anagen was accelerated, and the rapid activation and proliferation of Lgr5+ hair follicle stem cells (HFSCs) were observed in the treatment group. The RNA-seq, qPCR and WB results indicated that the Wnt pathway was significantly activated after CO2FL treatment. Improvement achieved with CO2FL treatment in clinical trial. CONCLUSIONS: The results of this study suggest that CO2FL treatment can promote hair regrowth by activating Lgr5+ HFSCs and upregulating the Wnt/ß-catenin pathway. Clinical trial results demonstrated that CO2FL treatment will be a promising therapeutic regimen for alopecia. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Elderly Women Have a Higher Survival Rate of Grafted Donor Fat than Do Young Women Under the Influence of Low Estrogen Conditions.

BACKGROUND: Fat grafting is widely used in breast reconstruction and aesthetic plastic surgery. However, the success rate and effects of fat grafting, especially in elderly female donors, are observed. This study aimed to explore the difference in the survival rate of donor fat from elderly women and young women in fat grafting. METHODS: We collected adipose tissue samples from two healthy Chinese women: a young woman and an elderly woman. In addition, adipose tissue samples were collected from female nude mice in four experimental groups-CON-Y, CON-O, OVX-Y, and OVX-O-after fat transplantation. Grafts were harvested, weighed, and subjected to assessment of histology and angiogenesis. RESULTS: An ovariectomy model was successfully established to validate the effect of low estrogen levels on fat grafting results. Due to the influence of low estrogen levels, the graft survival rate of donor site fat was significantly higher in elderly women than in young women, accompanied by a lesser degree of angiogenesis. Low estrogen levels led to adipocyte hypertrophy, which may be related to decreased AQP-7 expression. CONCLUSIONS: AQP-7 downregulation due to low estrogen levels induces adipocyte hypertrophy, and donor fat from elderly women exhibits a higher survival rate after fat transplantation. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .