Expression of bone morphogenetic protein-7 in human scalp skin and hair follicles.
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Bone Morphogenetic Protein 7↗
Biomedical subjects
H A Assaf
Publications and source records attributed to H A Assaf.
Age-associated decrease of CD1d protein production in normal human skin.
BACKGROUND: CD1d belongs to a family of antigen-presenting molecules structurally related to the classical major histocompatibility complex class I proteins. OBJECTIVES: To examine the expression pattern of CD1d protein in normal human skin with ageing. METHODS: Twenty normal human skin biopsy specimens were obtained from 20 healthy individuals. The latter were divided into three age groups: children (5-20 years), adults (21-50 years) and the elderly (51-81 years). The intensity of CD1d protein production was examined in human skin using immunofluorescent and immunoalkalinephosphatase staining methods. RESULTS: In the epidermis, CD1d protein production was strong in the skin of the children and declined gradually with age, being moderate in adults and weak in the elderly. As compared with values in children, there was a statistically significant decrease (P<0.05) in CD1d protein production in the elderly. In the dermis, CD1d protein production was strong in the fibroblasts, sweat glands, sebaceous glands, blood vessels and hair follicles regardless of age. CONCLUSIONS: Our study reports a decreased CD1d protein production in normal human skin with ageing. The clinical ramifications of these observations mandate further investigations.
Adolescent↗
Human scalp skin and hair follicles express neurotrophin-3 and its high-affinity receptor tyrosine kinase C, and show hair cycle-dependent alterations in expression.
BACKGROUND: Neurotrophin (NT)-3 and its high-affinity receptor tyrosine kinase C (Trk C) are essential for nervous system development. These members of the NT family are also involved in murine hair morphogenesis and cycling. However, their role in human hair follicle (HF) biology remains to be elucidated. OBJECTIVES: To explore the role of NTs in human skin and HF biology. METHODS: The immunoreactivity (IR) of NT-3 and Trk C was studied in human scalp skin and HFs by immunofluorescent and light microscopic immunohistology. Skin biopsies were obtained from normal human scalp containing mainly anagen VI HFs from women (age 53-57 years) undergoing elective plastic surgery. RESULTS: Both NT-3 and Trk C showed prominent, yet distinct, IR patterns in human scalp anagen HFs (anagen VI), whereas they were weakly expressed in catagen and increased again in telogen HFs. Within HF compartments, NT-3 IR was prominent in the outer root sheath, inner root sheath, dermal papilla and connective tissue sheath. Trk C IR was prominent in all HF epithelial and mesenchymal compartments. Outside the HF, both NT-3 and Trk C showed prominent IR in the epidermis, sebaceous glands and sweat glands. CONCLUSIONS: These observations provide the first indication that NT-3 and Trk C are expressed in human scalp skin and HFs, and suggest that Trk C-mediated signalling is involved not only in murine but also in human HF biology. They may be useful in determining therapeutic strategies for the treatment of hair cycle and skin-related disorders.
Epithelial Cells↗
Expression of CD1d in human scalp skin and hair follicles: hair cycle related alterations.
BACKGROUND: CD1d belongs to a family of antigen presenting molecules that are structurally and distantly related to the classic major histocompatibility complex class I (MHC I) proteins. However, unlike MHC I molecules, which bind protein antigens, CD1d binds to lipid and glycolipid antigens. CD1d is expressed by cells of lymphoid and myeloid origin, and by cells outside of the lymphoid and myeloid lineages, such as human keratinocytes of psoriatic skin. AIMS: To investigate whether CD1d is also expressed in sun exposed skin and in the immuno-privileged anagen hair follicle. MATERIALS/METHODS: CD1d immunoreactivity was studied in human scalp skin and hair follicles of healthy women in situ by immunofluorescent and light microscopic immunohistology. Skin biopsies were obtained from normal human scalp containing mainly anagen VI hair follicles from women (age, 53-57 years) undergoing elective plastic surgery. RESULTS: CD1d showed strong immunostaining in human scalp skin epidermis, pilosebaceous units, and eccrine glands. In the epidermis, CD1d was strongly expressed by basal and granular keratinocytes. In hair follicles, CD1d was expressed in the epithelial compartment and showed hair cycle related alterations, with an increase in the anagen and a reduction in the catagen and telogen phases. CONCLUSIONS: These results suggest that CD1d plays a role in human scalp skin immunology and protection against lipid antigen rich infectious microbes. They also raise the question of whether keratinocytes of the immuno-privileged anagen hair follicle can present lipid antigens to natural killer T cells. These data could help provide new strategies for the manipulation of hair related disorders.
Antigens, CD1↗