Journal: eLife
Article Title: TLR2 regulates hair follicle cycle and regeneration via BMP signaling
doi: 10.7554/eLife.89335
Figure Lengend Snippet: TLR2-GFP reporter mouse skin sections were immunostained with anti-GFP to assess TLR2 expression in the hair follicles. ( A ) Representative confocal images of P21 first telogen hair follicle immunostained for TLR2-GFP, CD34 (bulge stem cells), P-cad (secondary hair germ [sHG]), and DAPI (nuclei). The green color in the surface rendering panel represents TLR2 expression, and other surfaces show co-localization between TLR2 and specific markers. TLR2 is present in bulge, sHG, and dermal papilla (DP) cells. P represents postnatal days. Scale bar is 10 μm. ( B ) TLR2-GFP in P28 anagen was co-immunostained with CD49f of basement membrane outlining the DP. Scale bar is 10 μm. ( C ) TLR2 is co-localized to the sHG lineage (P-cad + layers), DP, and outer root sheath (ORS) lineage. Scale bar is 20 μm. ( D ) TLR2-GFP in P28 anagen was co-immunostained with CD34 in old bulge ( D ) and Ker5 in ORS ( E ) revealing TLR2 localization to the old bulge, ORS, but not inner root sheath (IRS). Scale bars are 20 μm. ( F ) Co-immunostaining of TLR2-GFP in P38 catagen hair follicle with Ker5 in ORS lineage cells showing co-localization of TLR2 with ORS and bulge. Scale bar is 20 μm. ( G ) P41 late catagen hair follicle immunostained for TLR2 and CD34 showing co-localization of TLR2 to the old bulge, new bulge, sHG, and DP. Scale bar is 20 μm. ( H ) P53 second telogen hair follicle immunostained for TLR2, CD34, and P-cad reveals co-localization of TLR2 to the bulge, sHG, and DP. Scale bar is 20 μm. ( I ) Quantification of TLR2 fluorescent intensity in bulge cells at different phases showing TLR2 upregulation in anagen. N=3 for each group. ( J ) Quantitative polymerase chain reaction (qPCR) analysis of Tlr2 mRNA expression in FACS-purified mouse HFSCs in anagen, telogen, and catagen. N=3 or 4 per group. ( K ) qPCR analysis of Tlr2 mRNA expression in mouse epidermal cells and FACS-purified HFSCs showed significantly higher Tlr2 expression in HFSCs compared with raw epidermal cells. N=6 mice per group. All bar graphs are mean ± s.e.m. Two-tailed unpaired t-test ( K ) or Kruskal-Wallis test with Dunn’s post hoc test ( I, J ) was used to determine statistical difference. A p-value ≤ 0.05 was considered to be statistically significant.
Article Snippet: After starvation, cells were incubated for 2 hr with or without TLR2 blocking antibody (Invivogen cat.# mab2-mtlr2) followed by incubation with Pam3CSK4 (Invivogen cat.# tlrl-pms) for 24 hr.
Techniques: Expressing, Membrane, Immunostaining, Real-time Polymerase Chain Reaction, Purification, Two Tailed Test