Expression and function of ryanodine receptors in human melanocytes

Abstract

We investigated the expression of ryanodine receptors (RyRs) in cultured human melanocytes with immunocytochemistry and reverse transcriptase-polymerase chain reaction. With the use of a monoclonal antibody, RyR immunoreactivity was detected in the cytoplasm of melanocytes, and was further confirmed by RT-PCR assay. The PCR products were cut with restriction enzymes specific for each RyR isoform. Using the RyR1-specific restriction enzyme SacI yielded fragments of 300, 100, and 130 base pairs, consistent with the expression of RyR1 isoforms. The function of RyR in Ca(2+) signaling was investigated using single-cell fura-2 imaging. Ryanodine (1 to approximately 100 microM) induced significant elevation of cytoplasmic Ca(2+) in single human melanocytes in a dose-dependent manner. The ryanodine-induced [Ca(2+)](i) increase was inhibited by neomycin. Furthermore, ryanodine inhibited proliferation and stimulated pigmentation of human melanocytes. This study demonstrates that the RyR1 isoform is expressed in cultured human melanocytes, and suggests that the RyR may be involved in regulating the intracellular Ca(2+) responses involved in proliferation and pigmentation of cultured human melanocytes.

In Vitro Study of the Effects of Five Chemically Modified Tetracycline (CMT) Analogs on Human Epidermal Melanogenesis: Potential as Novel Anti-Melanogenic Agents

“…An elevation in intracellular calcium ion (Ca 2+ ) concentration plays an essential role in the activation of melanin biosynthesis [61] and promotes dendrite formation in human melanocytes [62]. Additionally, primary human melanocytes have been shown to express the ryanodine receptor (RyR), which regulates intracellular calcium (Ca 2+ ) responses that are closely linked with the proliferation and pigmentation of human melanocytes [63]. Elevated levels of intracellular calcium within keratinocytes enhanced melanin transfer from melanocytes, resulting in increased pigmentation.…”

The effect of iron on the expression levels of calcium related gene in cisplatin resistant epithelial ovarian cancer cells

“…While RYRs , a class of Ca 2+ releasing channels, are rarely associated with cancer, they were reported to regulate proliferation of melanocytes and migration of T cells and astrocytes [ 25 , 26 ]. RYR1 is mainly expressed in skeletal muscle and although in small amounts, it is found in the heart muscle, smooth muscle, stomach, kidney, thymus, cerebellum, Purkinje cells, adrenal gland, testicle in the ovaries and B-lymphocytes [ 27 ].…”