TY - JOUR
T1 - Autophagy is essential for maintaining the growth of a human (mini-)organ
T2 - Evidence from scalp hair follicle organ culture
AU - Parodi, Chiara
AU - Hardman, Jonathan A.
AU - Allavena, Giulia
AU - Marotta, Roberto
AU - Catelani, Tiziano
AU - Bertolini, Marta
AU - Paus, Ralf
AU - Grimaldi, Benedetto
N1 - Funding Information:
I have read the journal’s policy and the authors of this manuscript have the following competing interests. A minor component of this study was supported by a basic research grant to CP from the company that markets the anti hair-loss product containing the principal ingredients used in the experiments (Giuliani spa, Milan, Italy), for which RP consults. MB is a part-time employee of a company that specializes in translational skin and hair research (Monasterium Laboratory, Münster, Germany).
PY - 2018/3/1
Y1 - 2018/3/1
N2 - Autophagy plays a crucial role in health and disease, regulating central cellular processes such as adaptive stress responses, differentiation, tissue development, and homeostasis. However, the role of autophagy in human physiology is poorly understood, highlighting a need for a model human organ system to assess the efficacy and safety of strategies to therapeutically modulate autophagy. As a complete, cyclically remodelled (mini-)organ, the organ culture of human scalp hair follicles (HFs), which, after massive growth (anagen), spontaneously enter into an apoptosis-driven organ involution (catagen) process, may provide such a model. Here, we reveal that in anagen, hair matrix keratinocytes (MKs) of organ-cultured HFs exhibit an active autophagic flux, as documented by evaluation of endogenous lipidated Light Chain 3B (LC3B) and sequestosome 1 (SQSTM1/p62) proteins and the ultrastructural visualization of autophagosomes at all stages of the autophagy process. This autophagic flux is altered during catagen, and genetic inhibition of autophagy promotes catagen development. Conversely, an anti-hair loss product markedly enhances intrafollicular autophagy, leading to anagen prolongation. Collectively, our data reveal a novel role of autophagy in human hair growth. Moreover, we show that organ-cultured scalp HFs are an excellent preclinical research model for exploring the role of autophagy in human tissue physiology and for evaluating the efficacy and tissue toxicity of candidate autophagy-modulatory agents in a living human (mini-)organ.
AB - Autophagy plays a crucial role in health and disease, regulating central cellular processes such as adaptive stress responses, differentiation, tissue development, and homeostasis. However, the role of autophagy in human physiology is poorly understood, highlighting a need for a model human organ system to assess the efficacy and safety of strategies to therapeutically modulate autophagy. As a complete, cyclically remodelled (mini-)organ, the organ culture of human scalp hair follicles (HFs), which, after massive growth (anagen), spontaneously enter into an apoptosis-driven organ involution (catagen) process, may provide such a model. Here, we reveal that in anagen, hair matrix keratinocytes (MKs) of organ-cultured HFs exhibit an active autophagic flux, as documented by evaluation of endogenous lipidated Light Chain 3B (LC3B) and sequestosome 1 (SQSTM1/p62) proteins and the ultrastructural visualization of autophagosomes at all stages of the autophagy process. This autophagic flux is altered during catagen, and genetic inhibition of autophagy promotes catagen development. Conversely, an anti-hair loss product markedly enhances intrafollicular autophagy, leading to anagen prolongation. Collectively, our data reveal a novel role of autophagy in human hair growth. Moreover, we show that organ-cultured scalp HFs are an excellent preclinical research model for exploring the role of autophagy in human tissue physiology and for evaluating the efficacy and tissue toxicity of candidate autophagy-modulatory agents in a living human (mini-)organ.
UR - http://www.scopus.com/inward/record.url?scp=85050016610&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85050016610&partnerID=8YFLogxK
U2 - 10.1371/journal.pbio.2002864
DO - 10.1371/journal.pbio.2002864
M3 - Article
C2 - 29590104
AN - SCOPUS:85050016610
VL - 16
SP - e2002864
JO - PLoS Biology
JF - PLoS Biology
SN - 1544-9173
IS - 3
ER -