HSP27 Protects Skin From Ultraviolet B -Induced Photodamage by Regulating Autophagy and Reactive Oxygen Species Production

Abstract

Ultraviolet (UV) irradiation has been well documented to be linked with almost all skin problems we know, and both dermis and epidermis may be affected to varying degrees by UV irradiation. Every time when exposed to sunlight without protection, our skin will step closer to photoaging, leading to irreversible consequences ultimately. Heat shock protein 27 (HSP27) is a vital protein involved in cell growth, autophagy, apoptosis, drug resistance, tumor genesis and metastasis. Evidence suggests that the organism is subjected to various internal and external environmental stresses (heat, oxidative stress, organic toxicants, etc.), and HSP27 with high expression has protective function. However, the expression of HSP27 in coping with UV irradiation have not been examined thoroughly. In this study, photodamage models were developed through different doses of UVB irradiation in human epidermal keratinocytes (HEKs) (30 mJ/cm2), human dermal fibroblasts (HDFs) (150 mJ/cm2) and mouse skin (2,700 mJ/cm2). HSP27 knockdown decreased cell viability and increased the incidence of UVB-induced reactive oxygen species (ROS) production. We got consistent results in vivo and vitro. Compared with that in the UVB group, the expression of LC3B was significantly lower, while the expression of p62 was significantly higher in the UVB + si-HSP27 group. It was also revealed that HSP27 knockdown reduced the expressions of some antioxidants, such as superoxide dismutase (SOD) and catalase (CAT), which accelerated UVB-induced ROS release. Moreover, histological results showed that epidermis was thickened and collagen fibers were disorganized in the UVB + si-HSP27 group. These findings have demonstrated that HSP27 might play a photoprotective role in the UVB-induced skin damage process by maintaining the normal autophagy and antioxidant level. It is implied that HSP27 could be a potential therapeutic target of photodamage. However, determination of the definitive mechanism requires further exploration.

Rapamycin Protects Mouse Skin from Ultraviolet B-Induced Photodamage by Modulating Hspb2-Mediated Autophagy and Apoptosis

“…The experimental results in this study also con rmed this view. According to the previous ndings of our group, the protein expression level of Hsp27 was not signi cantly altered in UVB-induced photodamage models of epidermal keratin-forming cells and dermal broblasts, while its phosphorylated form, P-Hsp27, was signi cantly elevated and activated autophagy (12). Similar results were achieved in the experiments in this study.…”

“…Small heat shock protein 27 (Hspb2), a new member of the heat shock protein family, is highly represented in heart and skeletal muscle (11). Previous studies by our group have also shown that Hsp27 can protect the skin from UVB-induced photodamage by mediating autophagy and the production of reactive oxygen species (12). Rapamycin, a speci c inhibitor of mTOR, has been shown in many studies, both in vivo and in vitro, to have an important role in delaying aging and treating age-related diseases (13)(14)(15)(16).…”

Correlation between Serum Heat Shock Protein 27 and Interleukin- 17 Levels and Prognosis in Patients with Acute Myocardial Infarction

“…HSP27 may delay the process of atherosclerosis by inhibiting mitochondrial apoptosis pathway and reducing the level of reactive oxygen species(ROS) [17,23]. Meanwhile HSP27 can regulate apoptosis and autophagy, which plays an antiatherosclerotic role [24,25]. ShiC et al found that HSP27 inhibited cholesterol uptake by macrophages through down-regulated the expression of scavenger receptor-A (SR-A) in macrophages via NF-κ B pathway, and thus reduced the transformation of macrophages into foam cells[8].…”

Triple Silencing of HSP27, cFLIP, and CLU Genes Promotes the Sensitivity of Doxazosin-Induced Apoptosis in PC-3 Prostate Cancer Cells

“…Many signaling proteins are known to be involved in the apoptosis of prostate cancer cells. Heat shock protein 27 (HSP27) is a cell survival factor synthesized in response to stress, such as UV irradiation, oxidizing agents, inflammation, hypoxia, and tumors [ 9 , 10 , 11 ]. In the absence of stress, HSP27 plays an important role in maintaining cellular homeostasis as a molecular chaperone that folds, assembles, and transports polypeptides.…”