Presence of trauma and suicide risk: Personal control as a moderator.

Given past findings that have linked trauma and lack of personal control to greater suicidal risk in adults, the present study examined how trauma presence and personal control are uniquely involved in predicting suicidal risk in a sample of 469 college students. Regression analyses indicated that both trauma presence and personal control were significant predictors of suicidal risk, as was their interaction. The present findings suggest a need to consider both trauma presence and low personal control in assessing for suicidal risk in college students.

Quantitative proteomic analysis uncovers inhibition of melanin synthesis by silk fibroin via MITF/tyrosinase axis in B16 melanoma cells.

AIMS: Silk fibroin (SF), a natural product from silkworms, has been used to promote anti-inflammation, induce wound healing, and reduce melanin production. However, the underlying regulatory mechanism of SF on melanin production remains unknown. The aim of this study was to investigate the distinct regulatory mechanism of SF in B16 melanoma cells by applying quantitative proteomic approach. MATERIALS AND METHODS: B16 melanoma cells were treated with PBS, KA or SF for 48 h, respectively. Cell viability, melanin content, and tyrosinase activity were examined. A label-free quantitative proteomic approach was utilized to investigate the regulatory mechanism of SF. The differentially expressed proteins and their related biological processes were subsequently identified by bioinformatics methods. Furthermore, the identified differentially expressed proteins were validated by western blot. KEY FINDINGS: Both SF and KA were able to suppress the melanin synthesis of B16 melanoma cells without appreciable toxicity; yet, SF had a distinct effect on mushroom tyrosinase activity in vitro. Moreover, quantitative proteomic approach identified 141 proteins differentially expressed only in SF/Con group. Bioinformatic analysis of these proteins revealed that oxidation-reduction process, RNA processing, fatty acid degradation, as well as melanin biosynthetic process were enriched with SF treatment. The proteins associated with melanin biosynthetic process, including microphthalmia-associated transcription factor (MITF) and tyrosinase, were down-regulated in SF group, which was confirmed by western blot. SIGNIFICANCE: SF inhibited melanin synthesis in B16 melanoma cells via down-regulation of MITF and tyrosinase expression, which provides a rationale for future utilization of SF.

Injectable Desferrioxamine-Laden Silk Nanofiber Hydrogels for Accelerating Diabetic Wound Healing.

Dysangiogenesis and chronic inflammation are two critical reasons for diabetic foot ulcers. Desferrioxamine (DFO) was used clinically in the treatment of diabetic foot ulcers by repeated injections because of its capacity to induce vascularization. Biocompatible carriers that release DFO slowly and facilitate healing simultaneously are preferable options to accelerate the healing of diabetic wounds. Here, DFO-laden silk nanofiber hydrogels that provided a sustained release of DFO for more than 40 days were used to treat diabetic wounds. The DFO-laden hydrogels stimulated the healing of diabetic wounds. In vitro cell studies revealed that the DFO-laden hydrogels modulated the migration and gene expression of endothelial cells, and they also tuned the inflammation behavior of macrophages. These results were confirmed in an in vivo diabetic wound model. The DFO-laden hydrogels alleviated dysangiogenesis and chronic inflammation in the diabetic wounds, resulting in a more rapid wound healing and increased collagen deposition. Both in vitro and in vivo studies suggested potential clinical applications of these DFO-laden hydrogels in the treatment of diabetic ulcers.