1. Bald scalp in men with androgenetic alopecia retains hair follicle stem cells but lacks CD200-rich and CD34-positive hair follicle progenitor cells
Abstract:
Androgenetic alopecia (AGA), also known as common baldness, is characterized by a marked decrease in hair follicle size, which could be related to the loss of hair follicle stem or progenitor cells. To test this hypothesis, we analyzed bald and non-bald scalp from AGA individuals for the presence of hair follicle stem and progenitor cells.
Results:
C2orf40
HYAL1
Figure 2: Sources of variation for the two differentially expressed genes.
Figure 1: PCA mapping shows the complete separation between the two groups CD200+(red, bald) and CD200-(blue, not-bald)
CD200+
CD200-
HYAL1
C2orf40
Figure 3: Heat map showing the direct differential expression of the two genes that meet the threshold based p-value <0.05 and fold change of >2 or <-2
Figure 4: Volcano-plot of the differentially expressed genes p-value vs log-fold change based on 54,000 genes
Conclusion:
CD200+ cells exhibit decreased expression of HYAL1, which encodes hyaluronidase, an enzyme responsible for extracellular matrix degradation and cell proliferation. C2orf40 is upregulated. This ORF encodes a protein called auguring responsible for G1 to G0 cell cycle transition. Overexpression of this protein would keep cells in senescence. According to the paper, CD200+ cells are present in bald men which fits with the predicted effect of the differential expression of these genes.