GDF-5 induces epidermal stem cell migration via RhoA-MMP9 signalling.

The migration of epidermal stem cells (EpSCs) is critical for wound re-epithelization and wound healing. Recently, growth/differentiation factor-5 (GDF-5) was discovered to have multiple biological effects on wound healing; however, its role in EpSCs remains unclear. In this work, recombinant mouse GDF-5 (rmGDF-5) was found via live imaging in vitro to facilitate the migration of mouse EpSCs in a wound-scratch model. Western blot and real-time PCR assays demonstrated that the expression levels of RhoA and matrix metalloproteinase-9 (MMP9) were correlated with rmGDF-5 concentration. Furthermore, we found that rmGDF-5 stimulated mouse EpSC migration in vitro by regulating MMP9 expression at the mRNA and protein levels through the RhoA signalling pathway. Moreover, in a deep partial-thickness scald mouse model in vivo, GDF-5 was confirmed to promote EpSC migration and MMP9 expression via RhoA, as evidenced by the tracking of cells labelled with 5-bromo-2-deoxyuridine (BrdU). The current study showed that rmGDF-5 can promote mouse EpSC migration in vitro and in vivo and that GDF-5 can trigger the migration of EpSCs via RhoA-MMP9 signalling.

Arrayed microfluidic chip for detection of circulating tumor cells and evaluation of drug potency.

Circulating tumor cells (CTCs) from peripheral blood of cancer patients are considered as one of the most promising pharmacodynamic (PD) biomarkers due to its non-invasive property in disease diagnosis and prognosis. However, the detection of extremely low number of CTCs in patient blood requires methods with high sensitivity and accuracy. We fabricated an arrayed geometrically enhanced mixing (GEM) chip with a "dislocation herringbone" layout based on cell immunoaffinity. By optimizing the injection and rinsing flow rate, an average cell capture rate of 87.02% and an average capture purity of 99.58% were achieved using the human lung adenocarcinoma cell lines H1975. In addition, we determined the specificity, precision, accuracy, and detection limit of our chip. The results demonstrated the chip was stable, accurate and reliable for the "liquid biopsy" of lung cancer cells using the peripheral blood of patients. Our chip can also be used to evaluate the potency of different drugs against tumor cells in parallel due to the presence of four independent microchannels.

GDF-5 promotes epidermal stem cells proliferation via Foxg1-cyclin D1 signaling.

OBJECTIVE: Epidermal stem cells (EpSCs) can self-renew, which are responsible for the long-term maintenance of the skin, and it also plays a critical role in wound re-epithelization, but the mechanism underlying EpSCs proliferation is unclear. GDF-5, also known as BMP-14, is a member of the BMP family and can be used as a self-renewal supporter. Here, we studied the effects of GDF-5 on mouse EpSCs proliferation mechanism in wound healing. METHODS: Firstly, the effects of GDF-5 on EpSCs proliferation was tested by using CCK8 reagent and PCNA expression was analyzed by Western blotting. Secondly, we screened genes that promote EpSCs proliferation in the FOX and cyclin family by qPCR, and then the protein expression level of the selected genes was further analyzed by Western blotting. Thirdly, siRNA plasmids and pAdEasy adenovirus were transfected or infected, respectively, into mouse EpSCs to detect the effect of target genes on GDF-5-induced cell proliferation. Furthermore, we injected GDF-5 to a deep partial thickness burn mouse model for finding out whether EpSCs proliferation can be detected by immunohistochemical. Finally, the relevant target genes were analyzed by qPCR, immunoblotting, and dual-luciferase reporter gene detection. RESULTS: We discovered that 100 ng/ml recombinant mouse GDF-5 was the optimal concentration for promoting mouse EpSCs proliferation. Through preliminary screened by qPCR, we found that Foxg1 and cyclin D1 could be the downstream molecules of GDF-5, and the results were confirmed by Western blotting. And the effect of GDF-5 on mouse EpSCs proliferation was adjusted by Foxg1/cyclin D1 in vitro and in vivo. Besides, GDF-5-induced transcription of cyclin D1 was regulated by Foxg1-mediated cyclin D1 promoter activity. CONCLUSION: This paper showed that GDF-5 promotes mouse EpSCs proliferation via Foxg1-cyclin D1 signal pathway. It is suggested that GDF-5 may be a new approach to make EpSCs proliferation which can be used in wound healing.

(E)­phenethyl 3­(3,5­dihydroxy­4­isopropylphenyl) acrylate gel improves DNFB-induced allergic contact hypersensitivity via regulating the balance of Th1/Th2/Th17/Treg cell subsets.

(E)­phenethyl 3­(3,5­dihydroxy­4­isopropylphenyl) acrylate gels (THCA354) is a novel polyphenols acrylic acid derivative. To investigate the immunoregulatory mechanisms of THCA354, we established a mouse model of 2,4­dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD). Responses of Th1, Th2, Th17 and regulatory T cells (Tregs) were determined by flow cytometry, reverse-transcriptase polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA). Our study found that topical application of THCA354 gel could inhibit ear swelling, reduce inflammatory cell infiltration, down-regulate Th1/Th17 responses and enhance Th2/Treg responses. These findings indicated that THCA354 gel exerted its immunotherapeutic effects by modulating the balance of Th1/Th2/Th17/Treg cell subsets, suggesting that THCA354 gel could be used as a promising drug candidate for intervention of ACD.