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IFN-gamma is a potent inducer of catagenlike changes in cultured human anagen HF


#1

Interferon-gamma is a potent inducer of catagen-like changes in cultured human anagen hair follicles.

Br J Dermatol. 2005 Apr;152(4):623-31

BACKGROUND:
Interferon (IFN)-gamma appears to be an important hair cycle modulator in mice. It is unclear whether it has similar hair growth modulatory functions in human hair follicles.

OBJECTIVES:
To study whether IFN-gamma can be exploited to modulate the growth, pigmentation and/or cycling of organ-cultured human anagen scalp hair follicles, as an in vitro indicator system for how IFN-gamma affects human hair growth in vivo. This was correlated with the hair follicle expression patterns of IFN-gamma receptors alpha and beta. In addition, we wanted to establish a new, simple tool for the rapid experimental induction of catagen in vitro.

METHODS:
Normal human scalp hair follicles in the anagen VI stage of the hair cycle were cultured according to the method of Philpott et al., with or without IFN-gamma (50-1000 IU mL(-1)). Hair shaft elongation and pigmentation changes were measured, complemented by quantitative histomorphometry to assess changes in hair follicle cycling (hair cycle score), proliferation (Ki-67), melanogenesis (Masson-Fontana) and apoptosis (TUNEL). IFN-gamma receptors were also localized by immunofluorescence and EnVision technique. As transforming growth factor (TGF)-beta2 is a recognized key inducer of catagen in human hair follicles, TGF-beta2 expression was investigated by tyramide signal amplification and reverse transcription-polymerase chain reaction in anagen hair follicles treated with vehicle (phosphate-buffered saline) or IFN-gamma.

RESULTS:
IFN-gamma rapidly inhibited hair elongation in cultured human anagen hair follicles and induced morphological signs of catagen transformation after only 4 days of culture, i.e. faster than with other reported catagen-inducers (e.g. TGF-beta2). Proliferation was inhibited, apoptosis was increased and follicular melanogenesis was switched off in hair bulb keratinocytes treated in situ with IFN-gamma. Anagen hair follicles displayed strong IFN-gamma receptor alpha-like immunoreactivity, while the immunoreactivity for IFN-gamma receptor beta in the hair matrix was only weak. TGF-beta2 immunoreactivity and mRNA transcript levels were enhanced in hair follicles treated with IFN-gamma.

CONCLUSIONS:
These data suggest that IFN-gamma is a potent catagen inducer in normal human scalp hair follicles, which express cognate receptors, and show that IFN-gamma administration offers an excellent tool for experimental catagen induction in organ-cultured human hair follicles. This catagen induction probably occurs at least in part via upregulation of the recognized catagen-stimulatory growth factor TGF-beta2.


#2

» Interferon-gamma is a potent inducer of catagen-like changes in cultured
» human anagen hair follicles.

»
» Br J Dermatol. 2005 Apr;152(4):623-31
»
» BACKGROUND:
» Interferon (IFN)-gamma appears to be an important hair cycle modulator in
» mice. It is unclear whether it has similar hair growth modulatory functions
» in human hair follicles.
»
» OBJECTIVES:
» To study whether IFN-gamma can be exploited to modulate the growth,
» pigmentation and/or cycling of organ-cultured human anagen scalp hair
» follicles, as an in vitro indicator system for how IFN-gamma affects human
» hair growth in vivo. This was correlated with the hair follicle expression
» patterns of IFN-gamma receptors alpha and beta. In addition, we wanted to
» establish a new, simple tool for the rapid experimental induction of
» catagen in vitro.
»
» METHODS:
» Normal human scalp hair follicles in the anagen VI stage of the hair cycle
» were cultured according to the method of Philpott et al., with or without
» IFN-gamma (50-1000 IU mL(-1)). Hair shaft elongation and pigmentation
» changes were measured, complemented by quantitative histomorphometry to
» assess changes in hair follicle cycling (hair cycle score), proliferation
» (Ki-67), melanogenesis (Masson-Fontana) and apoptosis (TUNEL). IFN-gamma
» receptors were also localized by immunofluorescence and EnVision technique.
» As transforming growth factor (TGF)-beta2 is a recognized key inducer of
» catagen in human hair follicles, TGF-beta2 expression was investigated by
» tyramide signal amplification and reverse transcription-polymerase chain
» reaction in anagen hair follicles treated with vehicle (phosphate-buffered
» saline) or IFN-gamma.
»
» RESULTS:
» IFN-gamma rapidly inhibited hair elongation in cultured human anagen hair
» follicles and induced morphological signs of catagen transformation after
» only 4 days of culture, i.e. faster than with other reported
» catagen-inducers (e.g. TGF-beta2). Proliferation was inhibited, apoptosis
» was increased and follicular melanogenesis was switched off in hair bulb
» keratinocytes treated in situ with IFN-gamma. Anagen hair follicles
» displayed strong IFN-gamma receptor alpha-like immunoreactivity, while the
» immunoreactivity for IFN-gamma receptor beta in the hair matrix was only
» weak. TGF-beta2 immunoreactivity and mRNA transcript levels were enhanced
» in hair follicles treated with IFN-gamma.
»
» CONCLUSIONS:
» These data suggest that IFN-gamma is a potent catagen inducer in normal
» human scalp hair follicles, which express cognate receptors, and show that
» IFN-gamma administration offers an excellent tool for experimental catagen
» induction in organ-cultured human hair follicles. This catagen induction
» probably occurs at least in part via upregulation of the recognized
» catagen-stimulatory growth factor TGF-beta2.

thanks for this study David. you’ve consistantly done good things for us all by posting this type of stuff that will someday prove very helpful to us all. We all appreciate your efforts. and i really do think that for all your hard work you deserve a vacation and i do think you should consider going to hawaii where you can see the historic peal harbor.