Activation of VEGF receptors in response to UVB promotes cell proliferation and melanogenesis of normal human melanocytes.

VEGF receptors (VEGFRs) are high-affinity receptors for VEGF and signaling via VEGFRs extends beyond the classical roles in blood vessel formation. We previously showed VEGFRs were also expressed in epidermal keratinocytes and activation of VEGFR-2 by ultraviolet B (UVB) was involved in the pro-survival mechanism. Here, we show that both VEGF165 and UVB enhanced the expression of VEGFRs (including VEGFR-1, VEGFR-2 and NRP-1) in normal human melanocytes, and increased expression of VEGFRs by UVB was mediated through hypoxia and oxidative stress. Also, VEGF165 and UVB promoted tyrosine phosphorylation of VEGFR-1 and VEGFR-2, and UVB-induced phosphorylation of VEGFR-1 and VEGFR-2 required PKA but not P38 MAPK. In addition, UVB and VEGF165 contributed to the over-expression of melanogenic proteins in melanocytes, which could be reduced by neutralization of VEGFR-1 and/or VEGFR-2. UVB, but not VEGF165 promoted cell proliferation, while neutralization of VEGFR-1 and/or VEGFR-2 abolished this effect. UVB showed stronger than VEGF165 in promoting tyrosinase activity and melanin production, while neutralization of VEGFR-2 was stronger in reducing these effects than that of VEGFR-1. Furthermore, tranexamic acid (TA) decreased tyrosinase activity and melanin production via inhibiting activation of VEGFRs and subsequent expression of melanogenic proteins in melanocytes. Taken together, we demonstrate that VEGFRs are functionally involved in UVB-induced melanogenesis, and TA can inhibit melanogenesis at least in part by targeting VEGFRs in melanocytes.

[Consensus on collaborative ethical review of multi-center clinical trials of new drugs of traditional Chinese medicine (version 1.0)].

At present, the issues regarding multi-center clinical trials of new drugs of traditional Chinese medicine(TCM) remain: the lack of agreement on the content and scope of the ethical review among the ethics committee members of the center and the participating units results in repeated review, which leads to a time-consuming ethical review process. Moreover, the review capabilities of the ethics committees of various research centers are uneven, which is not necessarily beneficial to the protection of subjects' rights and safety. In view of the existing problems, to improve the efficiency of ethical review of multi-center clinical trials of new drugs of TCM and avoid repeated reviews, the TCM Clinical Evaluation Professional Committee of Chinese Pharmaceutical Association organized experts to formulate the "Consensus on collaborative ethical review of multi-center clinical trials of new drugs of TCM(version 1.0)"(hereinafter referred to as "Consensus"). The "Consensus" is formulated in accordance with the requirements of relevant documents such as but not limited to "the opinions on deepening the reform of the evaluation and approval system to encourage the innovation of pharmaceutical medical devices", "the regulations of ethical review of biomedical research involving human subjects". The "Consensus" covers the scope of application, formulation principles, conditions for the ethics committee of the center, sharing of ethical review resources, scope and procedure of collaborative review, rights and obligations, etc. The aims of the "Consensus" is to preliminarily explore and establish a scientific and operable ethical review procedure. Additionally, on the basis of fully protecting the rights and interests of the subjects, a collaborative ethical review agreement needs to be signed to clarify the ethical review responsibilities of all parties, to avoid repeated review, and to improve the efficiency and quality of ethical review in multi-center clinical trials of new drugs of TCM.

Tranexamic Acid Inhibits Angiogenesis and Melanogenesis in Vitro by Targeting VEGF Receptors.

Melasma is a common but complex skin condition concerning cosmetic problems. Tranexamic acid (TA) has been proved to be effective in treatment of melasma with still unclear mechanisms. Here, we show that VEGF165 enhanced the expression of VEGF receptors (VEGFRs, including VEGFR-1, VEGFR-2 and NRP-1) in human umbilical vein endothelial cells (HUVECs), which was attenuated by TA. VEGF165 also promoted tyrosine phosphorylation of VEGFR-1 and VEGFR-2 in HUVECs, which was again abolished by TA. TA further showed similar effects to neutralization of VEGFR-1 and VEGFR-2 in inhibiting cell proliferation, migration, invasion and tube formation of HUVECs induced by VEGF165, suggesting that TA could inhibit angiogenesis by targeting VEGFRs in HUVECs. In addition, VEGF165 enhanced the expression of VEGFRs and promoted tyrosine phosphorylation of VEGFR-1 and VEGFR-2 in normal human melanocytes, which were also attenuated by TA. Furthermore, TA showed similar effects to neutralization of VEGFR-1 and VEGFR-2 in inhibiting tyrosinase activity, melanin production and even melanogenic proteins induced by VEGF165, suggesting that TA could reduce melanogenesis via inhibiting activation of VEGFRs and subsequent expression of melanogenic proteins in melanocytes. Taken together, we demonstrate that TA can inhibit angiogenesis and melanogenesis in vitro at least in part by targeting VEGFRs, which may offer a new understanding of the pathogenesis of melasma as well as the molecular mechanism for TA in treatment of the disease.

[Primary study on mechanism of baicalin on the Th1/Th2 response in murine model of asthma].

OBJECTIVE: To study the mechanism of baicalin on the cytokines of Th1/Th2 in murine model of asthma. METHODS: The murine model of asthma was induced by OVA. Different doses of baicalin were orally administered to the mice respectively. The spleen cells were cultured 3 days for the measurement of IFN-gamma, IL-4, IL-5 and IL-10 by ELISA. After 2 days of culture, the spleen cells were treated with Trizol for extraction of total RNA. The gene expressions of T-bet, GATA-3 and STAT-6 were analyzed by RT-PCR. RESULTS: The treatment with baicalin obviously decreased the production of IL-4 and IL-5 and the gene expression of GATA-3, STAT-6, but increased the production of IL-10. CONCLUSION: Baicalin may modulate the Th1/Th2 balance mainly by altering the gene expressions of GATA-3 and STAT-6 in vivo and increasing the production of IL-10.

[Primary study on the mechanism of Ma Xing Shi Gan decoction on the Th1/Th2 response in a murine model of asthma].

OBJECTIVE: To study the mechanism of Ma Xing Shi Gan decoction on the cytokines of Th1/Th2 in a murine model of asthma. METHODS: The murine model of asthma was induced by OVA. Various doses of Ma Xing Shi Gan decoction were orally administered to the mice respectively. The spleen cells were cultured 3 days for measurement of IFN-gamma, IL4 and IL-5 by ELISA. After 2 days' culture, the spleen cells were treated with Trizol for extraction of total RNA. The gene expression of T-bet, GATA-3 and STAT-6 were analyzed by RT-PCR. RESULTS: After the treatment with Ma Xing Shi Gan decoction, the production of IL-4 and IL-5 and the gene expression of GATA-3, STAT-6 obviously decreased. CONCLUSION: Ma Xing Shi Gan decoction may modulate Thl/Th2 balance by suppressing the gene expression of GATA-3 and STAT-6 in vivo.