The Journal of investigative dermatology
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J. Invest. Dermatol. · Jun 2005
SCN9A mutations define primary erythermalgia as a neuropathic disorder of voltage gated sodium channels.
Primary erythermalgia is a rare disorder characterized by recurrent attacks of red, warm and painful hands, and/or feet. We previously localized the gene for primary erythermalgia to a 7.94 cM region on chromosome 2q. Recently, Yang et al identified two missense mutations of the sodium channel alpha subunit SCN9A in patients with erythermalgia. ⋯ A total of five of six mutations were located in highly conserved regions. One family with autosomal dominantly inherited erythermalgia was double heterozygous for two separate SCN9A mutations. These data establish primary erythermalgia as a neuropathic disorder and offers hope for treatment of this incapacitating painful disorder.
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J. Invest. Dermatol. · Dec 2004
An in vivo model of wound healing in genetically modified skin-humanized mice.
Cutaneous wound-healing disorders are a major health problem that requires the development of innovative treatments. Whithin this context, the search for reliable human wound-healing models that allow us to address both mechanistic and therapeutic matters is warranted. In this study, we have developed a novel invivo wound-healing model in a genetically modified human context. ⋯ In addition, when keratinocyte growth factor (KGF), a growth factor that has been shown to improve wound healing, was added to wounds during 3 d, the re-epithelialization was significantly accelerated. The present wound-healing model system provides a suitable in vivo tool to test gene transfer strategies for human skin repair. It also serves as a complementary platform for studies in genetically modified mice and as a model to evaluate pharmaceutical therapeutic approaches for impaired wound healing.
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J. Invest. Dermatol. · Aug 2004
The novel synthetic oleanane triterpenoid CDDO (2-cyano-3, 12-dioxoolean-1, 9-dien-28-oic acid) induces apoptosis in Mycosis fungoides/Sézary syndrome cells.
The novel synthetic oleanane triterpenoid CDDO (2-cyano-3, 12-dioxoolean-1, 9-dien-28-oic acid) can serve as a ligand for the peroxisome proliferator activator receptor-gamma (PPAR-gamma) and has been shown to inhibit cell proliferation, and to induce differentiation and apoptosis in tumor cell lines. Bexarotene is an RXR-selective retinoid that can induce apoptosis of mycosis fungoides (MF) and Sézary syndrome (SS) cells. Since the PPAR-gamma and RXR receptors can form heterodimers, we studied the effects of CDDO and its synergism with bexarotene on apoptosis in MF/SS cell lines (MJ, Hut78, and HH) and freshly isolated peripheral blood lymphocytes (PBL) from SS patients with circulating atypical T cells (CD4+CD26-). ⋯ In summary, CDDO induces apoptosis that is further enhanced by bexarotene and decreases the PPAR-gamma and bcl-xL proteins in MF/SS cells. CDDO's effects on MF/SS cells may be at least partly mediated through a PPAR-gamma-independent mechanism. Our findings suggest the rationale for further investigation of the clinical potential of CDDO, either alone or in combination with bexarotene for MF/SS patients.
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J. Invest. Dermatol. · May 2004
Proteinase-activated receptor-2 stimulates prostaglandin production in keratinocytes: analysis of prostaglandin receptors on human melanocytes and effects of PGE2 and PGF2alpha on melanocyte dendricity.
Prostaglandins (PG) are key mediators of diverse functions in the skin and several reports suggest that PG mediate post-inflammatory pigmentary changes through modulation of melanocyte dendricity and melanin synthesis. The proteinase-activated receptor 2 (PAR-2) is important for skin pigmentation because activation of keratinocyte PAR-2 stimulates uptake of melanosomes through phagocytosis in a Rho-dependent manner. In this report, we show that activation of keratinocyte PAR-2 stimulates release of PGE(2) and PGF(2alpha) and that PGE(2) and PGF(2alpha) act as paracrine factors that stimulate melanocyte dendricity. ⋯ The cAMP/protein kinase A system is known to modulate melanocyte dendrite formation through modulation of Rac and Rho activity. Neither PGF(2alpha) or PGE(2) elevated cAMP in human melanocytes showing that dendricity observed in response to PGE(2) and PGF(2alpha) is cAMP-independent. Our data suggest that PAR-2 mediates cutaneous pigmentation both through increased uptake of melanosomes by keratinocytes, as well as by release of PGE(2) and PGF(2alpha) that stimulate melanocyte dendricity through EP1, EP3, and FP receptors.
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J. Invest. Dermatol. · Feb 2004
Quantitative measures of the effect of the melanocortin 1 receptor on human pigmentary status.
Variation in human hair and skin color is the most striking visible aspect of human genetic variation. The only gene known to exert an effect on pigmentary within the normal population is the melanocortin-1 receptor (MC1R). Previous studies have used a Mendelian framework to relate MC1R genotype to phenotype, by measuring pigmentary status using categorical scales. ⋯ Approximately 67% of the variance in this model could be accounted for in terms of MC1R genotype. There was also a relation between MC1R status and hair color, most prominently for the b* axis (p<0.001), but also for the a* and L* scales (L*a*b*, CIE). We show for one of the most polymorphic human traits that it is possible to demonstrate meaningful relations between various physical characteristics: DNA sequence diversity, hair-wavelength-specific reflectance patterns, and chemical melanin assays.