title: Amber Light (590 nm) Induces the Breakdown of Lipid Droplets through Autophagy-Related Lysosomal Degradation in Differentiated Adipocytes.
abstract: Lipolysis in the adipocytes provides free fatty acids for other tissues in response to the energy demand. With the rapid increase in obesity-related diseases, finding novel stimuli or mechanisms that regulate lipid metabolism becomes important. We examined the effects of visible light (410, 457, 505, 530, 590, and 660 nm) irradiation on lipolysis regulation in adipocytes differentiated from human adipose-derived stem cells (ADSCs). Interestingly, 590 nm (amber) light irradiation significantly reduced the concentration of lipid droplets (LDs). We further investigated the lipolytic signaling pathways that are involved in 590 nm light irradiation-induced breakdown of LDs. Immunoblot analysis revealed that 590 nm light irradiation-induced phosphorylation of hormone-sensitive lipase (HSL) was insufficient to promote reduction of LDs. We observed that 590 nm light irradiation decreased the expression of perilipin 1. We found that 590 nm light irradiation, but not 505 nm, induced conversion of LC3 I to LC3 II, a representative autophagic marker. We further demonstrated that the lysosomal inhibitors leupeptin/NH4Cl inhibited 590 nm light irradiation-induced reduction of LDs in differentiated adipocytes. Our data suggest that 590 nm light irradiation-induced LD breakdown is partially mediated by autophagy-related lysosomal degradation, and can be applied in clinical settings to reduce obesity.
authors.affiliation: Basic Research &Innovation Division, Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea.
authors.forename: Min Sik
authors.initials: MS
authors.lastname: Choi
authors.affiliation: Basic Research &Innovation Division, Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea.
authors.forename: Hyoung-June
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Basic Research &Innovation Division, Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea.
authors.forename: Mira
authors.initials: M
authors.lastname: Ham
authors.affiliation: Gyeonggi Bio Center, Gyeonggi Institute of Science &Technology Promotion, Suwon, Republic of Korea.
authors.forename: Dong-Hwa
authors.initials: DH
authors.lastname: Choi
authors.affiliation: Basic Research &Innovation Division, Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea.
authors.forename: Tae Ryong
authors.initials: TR
authors.lastname: Lee
authors.affiliation: Basic Research &Innovation Division, Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 446-729, Republic of Korea.
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Shin
mesh_terms: D017667:Adipocytes / Q000378:metabolism / Q000502:physiology*; D018647:Amber; D001343:Autophagy / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D006801:Humans; D008049:Lipase / Q000378:metabolism; D066292:Lipid Droplets / Q000378:metabolism / Q000502:physiology*; D050356:Lipid Metabolism / Q000502:physiology; D008066:Lipolysis / Q000502:physiology; D008247:Lysosomes / Q000502:physiology*; D000070778:Perilipin-1 / Q000378:metabolism; D010766:Phosphorylation / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology
chemical_list: D018647:Amber; D000070778:Perilipin-1; D008049:Lipase