Autophagy: Multiple Mechanisms to Protect Skin from Ultraviolet Radiation-Driven Photoaging

Abstract

Autophagy is an essential cellular process that maintains balanced cell life. Restriction in autophagy may induce degenerative changes in humans. Natural or pathological aging of susceptible tissues has been linked with reduced autophagic activity. Skin photoaging is an example of such pathological condition caused by ambient solar UV radiation exposure. The UV-induced production of reaction oxygen species (ROS) has been linked to the promotion and progression of the photoaging process in exposed tissues. Accordingly, it has been suggested that autophagy is capable of delaying the skin photoaging process caused by solar ultraviolet (UV), although the underlying mechanism is still under debate. This review highlights several plausible mechanisms by which UV-induced ROS activates the cellular signaling pathways and modulates the autophagy. More specifically, the UV-mediated regulation of autophagy and age-related transcription factors is discussed to pinpoint the contribution of autophagy to antiphotoaging effects in the skin. The outcome of this review will provide insights into design intervention strategies for delaying the phenomenon of sunlight-induced photodamage, photoaging, and other aging-related chronic diseases based on factors that activate the autophagy process in the skin.

Ceria Nanoparticles Decrease UVA-Induced Fibroblast Death Through Cell Redox Regulation Leading to Cell Survival, Migration and Proliferation

“…The human skin is prone to photoaging due largely to UVinduced excessive production of ROS. The effect is compounded by a concomitant depletion of the endogenous antioxidant system (Shindo et al, 1994;Gęgotek et al, 2017;Oliveira et al, 2019) as a result of oxidative damage in cellular components (Photoaging et al, 2019). Our results show that pre-treatment with nanoceria decreased L929 cells UVA-induced ROS production 24 h post-irradiation; with this effect persisting even after a further dose of UVA exposure.…”

Research progress of keratinocyte‐programmed cell death in UV‐induced Skin photodamage

“…Autophagy is a process associated with cathepsin, during which cells clear a surplus of components or injured proteins, lipids, and other cellular components via the lysosome. [44][45][46][47] Autophagy plays an important role in the maintenance of homeostasis in eukaryotes. 48 Under pathological conditions, excessive autophagy can cause a nonapoptotic form of PCD that is known as autophagic cell death.…”

“…45,49 The hallmarks of autophagic cell death are that it is controlled by autophagy proteins and exhibits classic morphological features such as the accumulation of autophagic vesicles and cytoplasmic vacuolization. 45,48 Autophagy has been reported to play a vital role in cancer, 47,[50][51][52] neurodegenerative disorders, 45 ageing 50 and inflammation. 48 There are three types of autophagy, depending on the route of substrate entry into lysosomes: macroautophagy, microautophagy and chaperone-mediated autophagy (CMA).…”

“…48 There are three types of autophagy, depending on the route of substrate entry into lysosomes: macroautophagy, microautophagy and chaperone-mediated autophagy (CMA). 45,47,48 Generally, the term autophagy refers to macroautophagy, 45,46,48 which occurs in three phases: the initiation of phagophores, elongation phase and final degradation phase. 46,47 During this process, receptor tyrosine kinases (RTKs) activate PI3K/Akt, which regulates mammalian target of rapamycin complex 1 (mTORC1).…”

Anti-Photoaging and Potential Skin Health Benefits of Seaweeds

“…The AP-1 induces the upregulation of matrix metalloproteinases (MMP) such as collagenase-1 (MMP-1), stromelysin-1 (MMP-3), and gelatinase A (MMP-2), which specifically degrade connective tissues such as collagen and elastin and indirectly inhibit the collagen synthesis in the skin [ 8 ]. Furthermore, prolonged UVR exposure is considered as a leading cause of photoaging, and its symptoms could be characterized by wrinkles, loss of skin tone, pigmentation (hypo- or hyperpigmentation), rough skin, dryness, sallowness, deep furrows, severe atrophy, melanoma, and many others [ 9 , 10 , 11 ]. Therefore, it is important to provide adequate photoprotection to prevent photoaging and other skin disorders due to the deleterious effects of UVR.…”