Nitric Oxide is a Paracrine Mediator of Ultraviolet-induced Melanogenesis
نویسندگان
چکیده
Ultraviolet (UV) radiation is the main physiological stimulus for human skin pigmentation. Within the epidermalmelanin unit, melanocytes synthesize and transfer melanin to the surrounding keratinocytes. Keratinocytes produce paracrine factors that affect melanocyte proliferation, dendricity, and melanin synthesis. In this report, we show that normal human keratinocytes secrete nitric oxide (NO) in response to UVA and UVB radiation, and we demonstrate that the constitutive isoform of keratinocyte NO synthase is involved in this process. Next, we investigate the melanogenic effect of NO produced by keratinocytes in response to UV radiation using melanocyte and keratinocyte cocultures. Conditioned media from UV-exposed keratinocytes stimulate tyrosinase activity of melanocytes. This effect is reversed by NO scavengers, suggesting an important role for NO in UVinduced melanogenesis. Moreover, melanocytes respond to NO-donors by decreased growth, enhanced dendricity, and melanogenesis. The rise in melanogenesis induced by NOgenerating compounds is associated with an increased amount of both tyrosinase and tyrosinase-related protein 1. These observations suggest that NO plays an important role in the paracrine mediation of UV-induced melanogenesis. ( J. Clin. Invest. 1997. 99:635–642.)
منابع مشابه
Nitric Oxide Functions; an Emphasis on its Diversity in Infectious Diseases
Nitric oxide is a short-lived mediator, which can be induced in a variety of cell types and produces many physiologic and metabolic changes in target cells. It is important in many biological functions and generated from L-arginine by the enzyme nitric oxide synthase. Nitric oxide conveys a variety of messages between cells, including signals for vasorelaxation, neurotransmission and cytotoxici...
متن کاملDifferential Expression of Nitric Oxide Synthase Isoforms nNOS and iNOS in Patients with Non-Segmental Generalized Vitiligo
Nitric oxide (NO) is involved in several biological processes, but its role in human melanogenesis is still not well understood. Exposure to UVA and UVB induces nitric oxide production in keratinocytes and melanocytes through the activation of constitutive nitric oxide synthase, increasing tyrosinase activity and melanin synthesis, whereas inducible nitric oxide synthase over expression might b...
متن کاملThe Role of Photolabile Dermal Nitric Oxide Derivates in Ultraviolet Radiation (UVR)-Induced Cell Death
Human skin is exposed to solar ultraviolet radiation comprising UVB (280-315 nm) and UVA (315-400 nm) on a daily basis. Within the last two decades, the molecular and cellular response to UVA/UVB and the possible effects on human health have been investigated extensively. It is generally accepted that the mutagenic and carcinogenic properties of UVB is due to the direct interaction with DNA. On...
متن کاملEvaluation of nitric oxide involvement in effect of lead on dependency to morphine in mice
In the present study, interactions between lead exposure with nitric oxide precursor (L-arginine) or nitric oxide synthase (NOS) inhibitor (L-NAME) on naloxone-induced jumping and diarrhea in morphine-dependent mice were examined. Chronic lead acetate (0.05%) exposure altered naloxone-induced jumping and diarrhea in mice. Jumping was decreased after 7 days and was unchanged 14 and 28 days after...
متن کاملRhamnetin attenuates melanogenesis by suppressing oxidative stress and pro-inflammatory mediators.
Rhamnetin is a naturally occurring polyphenolic compound. In this report, experimental evidence is presented on the suppression of melanogenesis by rhamnetin using B16 murine melanoma cells (B16 cells). To document the underlying anti-melanogenic action of rhamnetin, several key biochemical mediators were quantified: superoxide (O2(•-)), nitric oxide (·NO) and peroxynitrite (ONOO(-)) in vitro, ...
متن کامل