Exosomes released by keratinocytes modulate melanocyte pigmentation

Abstract

Cells secrete extracellular vesicles (EVs), exosomes and microvesicles, which transfer proteins, lipids and RNAs to regulate recipient cell functions. Skin pigmentation relies on a tight dialogue between keratinocytes and melanocytes in the epidermis. Here we report that exosomes secreted by keratinocytes enhance melanin synthesis by increasing both the expression and activity of melanosomal proteins. Furthermore, we show that the function of keratinocyte-derived exosomes is phototype-dependent and is modulated by ultraviolet B. In sum, this study uncovers an important physiological function for exosomes in human pigmentation and opens new avenues in our understanding of how pigmentation is regulated by intercellular communication in both healthy and diseased states.

Proteomic comparison defines novel markers to characterize heterogeneous populations of extracellular vesicle subtypes

“…Peptides were analyzed by LC-MS/MS using an Ultimate 3000 system (Dionex) coupled to an LTQ-Orbitrap XL mass spectrometer (Thermo Fisher Scientific). Proteins were denatured, reduced, alkylated and digested with trypsin as described previously (45,46) or trypsin/LysC. A nanoflow HPLC instrument (Ultimate 3000, Dionex) was coupled on-line to the LTQ-Orbitrap XL Hybrid Ion Trap-Orbitrap mass spectrometer (Thermo Scientific) and an RSLCnano system (Ultimate 3000, Thermo Scientific) to the Orbitrap Fusion Tribrid mass spectrometer (Thermo Scientific).…”

Exosomes as a novel pathway for regulating development and diseases of the skin (Review)

“…Barrier function is an irreplaceable function of the skin (16), and the skin contains various accessory organs (17). There are multiple types of cells that secrete exosomes in the skin, for example keratinocytes, fibroblasts and adipocytes secrete exosomes into other cells or body fluids to participate in biological activity (6,18,19).…”

“…Skin pigmentation requires close communication between cells. In the skin epidermis, melanocytes and keratinocytes form the epidermal melanin unit (6). Ultraviolet B is able to induce melanin production in melanoma cells (6).…”

“…In the skin epidermis, melanocytes and keratinocytes form the epidermal melanin unit (6). Ultraviolet B is able to induce melanin production in melanoma cells (6). The difference in skin color is controlled by the melanin content (61).…”

“…The development and function of the skin are affected by multiple factors, including environmental factors and hormones (5). Recently, exosome studies have indicated that some exosomes are involved in the physiological and pathological processes of the skin (6,7). Such findings have provided a novel perspective for the understanding of the molecular mechanisms involved in these processes.…”