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Signalling couples hair follicle stem cell quiescence with reduced histone H3 K4/K9/K27me3 for proper tissue homeostasis.

Lee J, Kang S, Lilja KC, Colletier KJ, Scheitz CJ, Zhang YV, Tumbar T - Nat Commun (2016)

Bottom Line: The level of marks over specific gene promoters did not correlate to mRNA level changes in quiescent HFSCs.Furthermore, removal of proliferation factors and addition of BMP4 reduced histone methylases and increased demethylases mRNAs in cultured skin epithelial cells.We conclude that signalling couples hair follicle stem cell quiescence with reduced H3 K4/K9/K27me3 levels for proper tissue homeostasis.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA.

ABSTRACT
Mechanisms of plasticity to acquire different cell fates are critical for adult stem cell (SC) potential, yet are poorly understood. Reduced global histone methylation is an epigenetic state known to mediate plasticity in cultured embryonic SCs and T-cell progenitors. Here we find histone H3 K4/K9/K27me3 levels actively reduced in adult mouse skin and hair follicle stem cells (HFSCs) during G0 quiescence. The level of marks over specific gene promoters did not correlate to mRNA level changes in quiescent HFSCs. Skin hypomethylation during quiescence was necessary for subsequent progression of hair homeostasis (cycle). Inhibiting BMP signal, a known HFSC anti-proliferative factor, elevated HFSC methylation in vivo during quiescence prior to proliferation onset. Furthermore, removal of proliferation factors and addition of BMP4 reduced histone methylases and increased demethylases mRNAs in cultured skin epithelial cells. We conclude that signalling couples hair follicle stem cell quiescence with reduced H3 K4/K9/K27me3 levels for proper tissue homeostasis.

No MeSH data available.


Related in: MedlinePlus

Distinct low levels of histone H3 K4/K9/K27me3 in quiescent (catagen) HFSCs.(a,b) Depiction of hair cycle and fate choices of bulge HFSCs during quiescence, before activation. (c,e) Immunofluorescence staining of histone methyl marks at hair cycle stages indicated (Bu, bulge; DP, dermal papillae; Ep, epidermis; Hg, hair germ; IL, inner layers; Mx, matrix; ORS, outer root sheath). Scale bars, 10 μm. (f) Western blot of H3K9me3 in histone extracts from FACS-isolated cells. (g) Quantification of fluorescence intensity of z-stack images of Foci+ and Foci- cells in the bulge from PD24 hair follicle sections shows a significant difference (Student's t-test). AU, Arbitrary Unit. Scale bar, 5 μm. (h) Fraction of H3K9me3 foci+ cells, quantified on cytospin of FACS-isolated cells derived from mice at PD25 (anagen, proliferation), PD34 (late anagen, ceasing proliferation) and PD47 (telogen, quiescence). (i) Western blot of H3K9me3 on FACS-isolated HFSCs at early anagen (EA) and late catagen (LC). Notice the reduction of H3K9me3 in late catagen. (j) Western blot of histone marks on total skin histone extracts from different stages of hair cycle. Notice the reduction of all three marks in catagen skin relative to other stages. All western blots showed a single band between 15 and 17 kDa region, which corresponds to the correct size of histone H3 protein. (k) Band intensities from j were quantified and normalized to total H3 to calculate the fold differences. Fold changes were averaged among mice at the same stage.
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f1: Distinct low levels of histone H3 K4/K9/K27me3 in quiescent (catagen) HFSCs.(a,b) Depiction of hair cycle and fate choices of bulge HFSCs during quiescence, before activation. (c,e) Immunofluorescence staining of histone methyl marks at hair cycle stages indicated (Bu, bulge; DP, dermal papillae; Ep, epidermis; Hg, hair germ; IL, inner layers; Mx, matrix; ORS, outer root sheath). Scale bars, 10 μm. (f) Western blot of H3K9me3 in histone extracts from FACS-isolated cells. (g) Quantification of fluorescence intensity of z-stack images of Foci+ and Foci- cells in the bulge from PD24 hair follicle sections shows a significant difference (Student's t-test). AU, Arbitrary Unit. Scale bar, 5 μm. (h) Fraction of H3K9me3 foci+ cells, quantified on cytospin of FACS-isolated cells derived from mice at PD25 (anagen, proliferation), PD34 (late anagen, ceasing proliferation) and PD47 (telogen, quiescence). (i) Western blot of H3K9me3 on FACS-isolated HFSCs at early anagen (EA) and late catagen (LC). Notice the reduction of H3K9me3 in late catagen. (j) Western blot of histone marks on total skin histone extracts from different stages of hair cycle. Notice the reduction of all three marks in catagen skin relative to other stages. All western blots showed a single band between 15 and 17 kDa region, which corresponds to the correct size of histone H3 protein. (k) Band intensities from j were quantified and normalized to total H3 to calculate the fold differences. Fold changes were averaged among mice at the same stage.

Mentions: Mouse HFSCs are an excellent model system for studying the link between SC plasticity and quiescence because they undergo synchronous phases of quiescence and proliferation that are tightly regulated. Furthermore, hair follicles have defined morphology, which permits unambiguous in situ identification of the SCs (bulge, Bu region), progenitor cells (matrix, Mx region) and differentiated lineages (inner layers, ILs; Fig. 1a). Furthermore, bulge HFSCs can be freshly sorted from skin in large quantities based on cell surface markers CD34 and α6-integrin, and this allows biochemical analyses, which are inaccessible to many other tissue systems. Hair homeostasis occurs in regenerative cycles (Fig. 1a,b) composed of successive synchronous stages of tissue remodelling: telogen (rest and quiescence of HFSCs), anagen (proliferation/differentiation of matrix progenitors and independent self-renewal of Bu HFSCs) and catagen (regression/apoptosis of progenitor and differentiated lineages, re-structuring of the SC niche and quiescence of the HFSCs)1415.


Signalling couples hair follicle stem cell quiescence with reduced histone H3 K4/K9/K27me3 for proper tissue homeostasis.

Lee J, Kang S, Lilja KC, Colletier KJ, Scheitz CJ, Zhang YV, Tumbar T - Nat Commun (2016)

Distinct low levels of histone H3 K4/K9/K27me3 in quiescent (catagen) HFSCs.(a,b) Depiction of hair cycle and fate choices of bulge HFSCs during quiescence, before activation. (c,e) Immunofluorescence staining of histone methyl marks at hair cycle stages indicated (Bu, bulge; DP, dermal papillae; Ep, epidermis; Hg, hair germ; IL, inner layers; Mx, matrix; ORS, outer root sheath). Scale bars, 10 μm. (f) Western blot of H3K9me3 in histone extracts from FACS-isolated cells. (g) Quantification of fluorescence intensity of z-stack images of Foci+ and Foci- cells in the bulge from PD24 hair follicle sections shows a significant difference (Student's t-test). AU, Arbitrary Unit. Scale bar, 5 μm. (h) Fraction of H3K9me3 foci+ cells, quantified on cytospin of FACS-isolated cells derived from mice at PD25 (anagen, proliferation), PD34 (late anagen, ceasing proliferation) and PD47 (telogen, quiescence). (i) Western blot of H3K9me3 on FACS-isolated HFSCs at early anagen (EA) and late catagen (LC). Notice the reduction of H3K9me3 in late catagen. (j) Western blot of histone marks on total skin histone extracts from different stages of hair cycle. Notice the reduction of all three marks in catagen skin relative to other stages. All western blots showed a single band between 15 and 17 kDa region, which corresponds to the correct size of histone H3 protein. (k) Band intensities from j were quantified and normalized to total H3 to calculate the fold differences. Fold changes were averaged among mice at the same stage.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835553&req=5

f1: Distinct low levels of histone H3 K4/K9/K27me3 in quiescent (catagen) HFSCs.(a,b) Depiction of hair cycle and fate choices of bulge HFSCs during quiescence, before activation. (c,e) Immunofluorescence staining of histone methyl marks at hair cycle stages indicated (Bu, bulge; DP, dermal papillae; Ep, epidermis; Hg, hair germ; IL, inner layers; Mx, matrix; ORS, outer root sheath). Scale bars, 10 μm. (f) Western blot of H3K9me3 in histone extracts from FACS-isolated cells. (g) Quantification of fluorescence intensity of z-stack images of Foci+ and Foci- cells in the bulge from PD24 hair follicle sections shows a significant difference (Student's t-test). AU, Arbitrary Unit. Scale bar, 5 μm. (h) Fraction of H3K9me3 foci+ cells, quantified on cytospin of FACS-isolated cells derived from mice at PD25 (anagen, proliferation), PD34 (late anagen, ceasing proliferation) and PD47 (telogen, quiescence). (i) Western blot of H3K9me3 on FACS-isolated HFSCs at early anagen (EA) and late catagen (LC). Notice the reduction of H3K9me3 in late catagen. (j) Western blot of histone marks on total skin histone extracts from different stages of hair cycle. Notice the reduction of all three marks in catagen skin relative to other stages. All western blots showed a single band between 15 and 17 kDa region, which corresponds to the correct size of histone H3 protein. (k) Band intensities from j were quantified and normalized to total H3 to calculate the fold differences. Fold changes were averaged among mice at the same stage.
Mentions: Mouse HFSCs are an excellent model system for studying the link between SC plasticity and quiescence because they undergo synchronous phases of quiescence and proliferation that are tightly regulated. Furthermore, hair follicles have defined morphology, which permits unambiguous in situ identification of the SCs (bulge, Bu region), progenitor cells (matrix, Mx region) and differentiated lineages (inner layers, ILs; Fig. 1a). Furthermore, bulge HFSCs can be freshly sorted from skin in large quantities based on cell surface markers CD34 and α6-integrin, and this allows biochemical analyses, which are inaccessible to many other tissue systems. Hair homeostasis occurs in regenerative cycles (Fig. 1a,b) composed of successive synchronous stages of tissue remodelling: telogen (rest and quiescence of HFSCs), anagen (proliferation/differentiation of matrix progenitors and independent self-renewal of Bu HFSCs) and catagen (regression/apoptosis of progenitor and differentiated lineages, re-structuring of the SC niche and quiescence of the HFSCs)1415.

Bottom Line: The level of marks over specific gene promoters did not correlate to mRNA level changes in quiescent HFSCs.Furthermore, removal of proliferation factors and addition of BMP4 reduced histone methylases and increased demethylases mRNAs in cultured skin epithelial cells.We conclude that signalling couples hair follicle stem cell quiescence with reduced H3 K4/K9/K27me3 levels for proper tissue homeostasis.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA.

ABSTRACT
Mechanisms of plasticity to acquire different cell fates are critical for adult stem cell (SC) potential, yet are poorly understood. Reduced global histone methylation is an epigenetic state known to mediate plasticity in cultured embryonic SCs and T-cell progenitors. Here we find histone H3 K4/K9/K27me3 levels actively reduced in adult mouse skin and hair follicle stem cells (HFSCs) during G0 quiescence. The level of marks over specific gene promoters did not correlate to mRNA level changes in quiescent HFSCs. Skin hypomethylation during quiescence was necessary for subsequent progression of hair homeostasis (cycle). Inhibiting BMP signal, a known HFSC anti-proliferative factor, elevated HFSC methylation in vivo during quiescence prior to proliferation onset. Furthermore, removal of proliferation factors and addition of BMP4 reduced histone methylases and increased demethylases mRNAs in cultured skin epithelial cells. We conclude that signalling couples hair follicle stem cell quiescence with reduced H3 K4/K9/K27me3 levels for proper tissue homeostasis.

No MeSH data available.


Related in: MedlinePlus