Exosome-mediated miR-4655-3p contributes to UV radiation-induced bystander effects.

Radiation-induced bystander effects (RIBEs) refer to a series of reactions displaying in nonirradiated cells triggered by signals from irradiated cells. Though bystander effects induced by ionizing radiation have been well studied, there are still limited data on ultraviolet(UV) induced bystander effects(UV-RIBEs). Studies have verified that exosomes, acting as a new tool of intercellular communication, participate in ionizing radiation-induced bystander effect. The purpose of what we studied was to explore the function of exosomes in UV-RIBEs, and seeking the relevant mechanism. Human skin fibroblasts (HSFs) were exposed to a single dose of ultraviolet A (UVA) radiation (20 J/cm2) or ultraviolet B (UVB) radiation (60 mJ/cm2), respectively. Exosomes were isolated from the culture medium of HSFs by differential ultracentrifugation. Three endpoints relevant to potodamage were used in the evaluation of UV-RIBEs, which including the cell proliferation, oxidative damage, and apoptosis. Our results showed that exosomes from UV-irradiated cells contributed to UV-RIBEs. The expression of miR-4655-3p in exosomes increased after UV radiation and exosomes assisted in the transportation of miR-4655-3p between cells. The upregulation of miR-4655-3p enhanced the UV-RIBEs in the bystander cells. MiR-4655-3p restrained the expression of E2F2 through direct binding to its 3'-UTR. In addition, E2F2 contributed to the cell proliferation and decreased oxidative damage of HSFs. To sum up that exosomal miR-4655-3p plays a crucial role in UV-RIBEs and this function mentioned partially related to the inhibition of E2F2.

Platelet-rich plasma regulating the repair of ultraviolet B-induced acute tissue inflammation: adjusting macrophage polarization through the activin receptor-follistatin system.

Ultraviolet B (UVB) is one of the most common exogenous factors in skin aging, especially photoaging. Once a large amount of UVB accumulates within a short period of time, skin tissue can become inflamed. It has also been found in clinics that platelet-rich plasma (PRP) can promote wound repair; therefore, the aim of this study was to identify the mechanism by which PRP repairs UVB-induced skin photodamage. We used PRP of Sprague-Dawley rats with the two-spin technique in the established acute UVB radiation photodamage model and harvested the corresponding skin after 1, 7, and 28 d. Hematoxylin and eosin staining was used to observe tissue inflammation. We found that PRP reduces inflammation in the early stages of UVB-induced acute skin damage, and then promotes the proliferation of collagen in the middle and late stages. Moreover, PRP can stimulate Act A and M1 polarization in the early stage, while inhibiting activin A (Act A) and inducing M2 polarization in the middle and late stages. In conclusion, this study demonstrates that PRP plays an important regulatory role in helping reduce UVB-induced acute skin tissue inflammation by adjusting macrophage polarization, which alleviates skin inflammation and stimulates collagen regeneration.

Costello syndrome with special cutaneous manifestations and HRAS G12D mutation: A case report and literature review.

BACKGROUND: Costello syndrome (CS, OMIM 218040) is a rare congenital disorder caused by mutations in HRAS. Previous studies reported that approximately 80% of patients with CS share the same pathogenic variant in HRAS gene in c.34G> A (p.G12S). Here, we report a CS patient with c.34G> A (p.G12D) variant in HRAS gene and she presented with special manifestation. METHODS AND RESULTS: We describe a 31-year-old female patient who presented with distinctive facial appearance, intellectual disability, dental abnormalities, hyperkeratosis of palmer and planter, loose skin at birth, papillomata on the face and nipples. The whole-exome sequencing (WES) technology provided by Haotian Biotechnology (China) confirmed p.G12D variant in HRAS gene. To elucidate the typical features of CS with p.G12D variant, we further reviewed these previously reported cases and found that patients with G12D variant died within three months after birth due to multiple organ failure. They had the typical facial characteristics, failure to thrive, skin and cardiac abnormalities, and gene testing confirmed the diagnosis of CS. CONCLUSION: To the best of our knowledge, this is the first article to report a patient with a p.G12D variant that had special but mild manifestation. Moreover, this report and literature review casts new light on the clinical features of p.G12D variant.

Applications and efficacy of platelet-rich plasma in dermatology: A clinical review.

The platelet-rich plasma (PRP) has been studied in bone-related applications for accelerating healing, and the proliferation and regeneration of tissue. Now the dermatological indications increase rapidly in recent years. We have reviewed clinical trials, comparative trials, and meta-analysis of PRP on dermatology through key words and reorganized them into facial rejuvenation, hair, scar, vitiligo, and synergistic effect with fractional CO2 , with a conclusion that PRP has significant improvements in dermatology. But the lack of RCTs and the limit of samples cannot provide sufficient enough evidence for general clinical applications. More RCTs are needed for the increasing demand of new dermatologic therapeutics, and we need adequate samples urgently to make the results more persuasive.