![]() ![]() Lipases play an important role in lipolysis. A study showed that basal lipolysis is increased and PKA-stimulated lipolysis increase is blocked in adipocytes of perilipin 1 knock-out mice 7, 8. Perilipin 1 is highly phosphorylated by cyclic AMP-dependent PKA 6. Perilipin 1 has two modes of action: downregulating basal lipolysis and mediating protein kinase A (PKA)-activated lipolysis. These include the lipolytic and anti-lipolytic mechanisms induced by lipolytic hormones such as adrenocorticotropic hormone (ACTH), anti-lipolytic hormones such as insulin, or LD-associated proteins such as perilipins and lipases 4, 5. ![]() Lipolysis is a series of processes involving several regulatory events 4. Thus, tight control of lipolysis is required not only for energy homeostasis, but also for the prevention of metabolic diseases. Decreased lipolysis activity in adipose tissues may lead to triglyceride (TG) accumulation in lipid droplets (LDs), causing unnecessary additional energy intake, which leads to obesity 2, 3. During fasting or exercise, mature adipocytes provide energy as free fatty acids for other tissues through a process known as lipolysis 1. 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.Īs the main reservoir of the body’s fuel, white adipose tissues play a critical role in energy storage and balance. We further demonstrated that the lysosomal inhibitors leupeptin/NH 4Cl inhibited 590 nm light irradiation-induced reduction of LDs in differentiated adipocytes. We found that 590 nm light irradiation, but not 505 nm, induced conversion of LC3 I to LC3 II, a representative autophagic marker. We observed that 590 nm light irradiation decreased the expression of perilipin 1. Immunoblot analysis revealed that 590 nm light irradiation-induced phosphorylation of hormone-sensitive lipase (HSL) was insufficient to promote reduction of LDs. We further investigated the lipolytic signaling pathways that are involved in 590 nm light irradiation-induced breakdown of LDs. Interestingly, 590 nm (amber) light irradiation significantly reduced the concentration of lipid droplets (LDs). 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). With the rapid increase in obesity-related diseases, finding novel stimuli or mechanisms that regulate lipid metabolism becomes important. Lipolysis in the adipocytes provides free fatty acids for other tissues in response to the energy demand. ![]()
0 Comments
Leave a Reply. |