title: Hoxc13 is a crucial regulator of murine hair cycle.
abstract: Hair follicles undergo cyclical growth and regression during postnatal life. Hair regression is an apoptosis-driven process strictly controlled by micro- and macro-environmental signals. However, how these signals are controlled remains largely unknown. Hoxc13, a member of the Hox gene family, is reported to play an important role in hair follicle differentiation. In the present study, we observed that Hoxc13 was highly expressed in the outer root sheath, matrix, medulla and inner root sheath of hair follicles in a hair cycle-dependent manner. We therefore investigated the role of Hoxc13 in hair follicle cycling. Injection of ShRNA (ShHoxc13) to suppress Hoxc13 in early anagen promoted premature catagen entry, shown by significantly decreased hair length and hair bulb size, increased percentage of catagen hair follicles, hair cycle score and TUNEL+ cells and inhibited proliferation. In contrast, local injection of recombinant Hoxc13 polypeptide (rhHoxc13) during the late anagen phase prolonged the anagen phase. Additionally, rhHoxc13 injections during the telogen phase significantly promoted hair growth and induced the anagen progression. At the molecular level, the expression of phosphorylated smad2 (p-smad2), a key factor of active TGF-β1 signaling, was up-regulated in the ShHoxc13-treated hair follicles and down-regulated in rhHoxc13-treated hair follicles, suggesting that Hoxc13 might block anagen-catagen transition by inhibiting the TGF-β1 signaling. Taken together, our data strongly suggest that Hoxc13 is a novel and crucial regulator of the hair cycle. This might also provide an understanding of the mechanism of the 'hair cycle clock' and the development of alopecia treatments.
authors.affiliation: Department of Dermatology, Daping Hospital, The Third Military Medical University, Chongqing, 400042, China.
authors.forename: Weiming
authors.initials: W
authors.lastname: Qiu
authors.affiliation: "111" Project Laboratory of Biomechanics and Tissue Repair, College of Bioengineering, Chongqing University, Chongqing, 400044, China.
authors.forename: Mingxing
authors.initials: M
authors.lastname: Lei
authors.affiliation: Department of Dermatology, Daping Hospital, The Third Military Medical University, Chongqing, 400042, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Tang
authors.affiliation: Department of Dermatology, Daping Hospital, The Third Military Medical University, Chongqing, 400042, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Yan
authors.affiliation: Department of Dermatology, Daping Hospital, The Third Military Medical University, Chongqing, 400042, China.
authors.forename: Xuhong
authors.initials: X
authors.lastname: Wen
authors.affiliation: Department of Dermatology, Daping Hospital, The Third Military Medical University, Chongqing, 400042, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Dermatology, Daping Hospital, The Third Military Medical University, Chongqing, 400042, China.
authors.forename: Ranjing
authors.initials: R
authors.lastname: Tan
authors.affiliation: Department of Dermatology, Daping Hospital, The Third Military Medical University, Chongqing, 400042, China.
authors.forename: Duan
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Dermatology, Daping Hospital, The Third Military Medical University, Chongqing, 400042, China. wjjjj@163.com.
authors.forename: Jinjin
authors.initials: J
authors.lastname: Wu
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D005260:Female; D018859:Hair Follicle / Q000166:cytology / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D051899:Smad2 Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D018398:Homeodomain Proteins; C485834:Hoxc13 protein, mouse; D051899:Smad2 Protein; C497783:Smad2 protein, mouse
keywords: Apoptosis; Hair cycle; Hoxc13; Phosphorylated smad2; Proliferation