title: Melanosome uptake is associated with the proliferation and differentiation of keratinocytes.
abstract: Melanosomes are synthesized in melanocytes and transferred to neighboring keratinocytes. However, the associations of melanosome uptake with the proliferation and differentiation of keratinocytes are not fully understood. We examined the associations of melanosome uptake with keratinocyte differentiation and proliferation. SV40T-transformed human epidermal keratinocytes (SV-HEKs) were treated with isolated melanosomes. The effects of melanosome uptake on the proliferation and differentiation of the keratinocytes were analyzed by Western blotting and flow cytometry. The relationship between melanosome uptake and keratinocyte differentiation status was verified by determining the melanin content in the cells. Melanosomes reduced the proliferation of SV-HEKs in a dose-dependent manner, but did not induce differentiation. Melanosome uptake was higher in differentiating keratinocytes compared to non-differentiating keratinocytes, and inhibited significantly by PAR-2 inhibitor. Melanosomes inhibit keratinocyte proliferation. Moreover, melanosome uptake is influenced by keratinocyte differentiation status, being highest in mid-stage differentiating keratinocytes in a PAR-2 dependent manner.
authors.affiliation: Department of Anatomy, School of Medicine, Chungnam National University, 266 Munhwa-ro, Daejeon, 301-747, Korea.
authors.forename: Hye-In
authors.initials: HI
authors.lastname: Choi
authors.forename: Kyung-Cheol
authors.initials: KC
authors.lastname: Sohn
authors.forename: Dong-Kyun
authors.initials: DK
authors.lastname: Hong
authors.forename: Young
authors.initials: Y
authors.lastname: Lee
authors.forename: Chang Deok
authors.initials: CD
authors.lastname: Kim
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Yoon
authors.forename: Jin Woon
authors.initials: JW
authors.lastname: Park
authors.forename: Sunggyun
authors.initials: S
authors.lastname: Jung
authors.forename: Jeung-Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Lee
mesh_terms: D001692:Biological Transport; D002118:Calcium / Q000494:pharmacology; D002454:Cell Differentiation; D002461:Cell Line, Transformed; D049109:Cell Proliferation; D006801:Humans; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism*; D008543:Melanins / Q000032:analysis / Q000494:pharmacology; D020460:Melanosomes / Q000378:metabolism*; D044464:Receptor, PAR-2
chemical_list: D008543:Melanins; D044464:Receptor, PAR-2; D002118:Calcium