[Multi-component content determination of Dracocephalum tanguticum by quantitative analysis of multi-components by single-marker].

This study aims to establish a method for the simultaneous determination of 7 active components in Dracocephalum tanguticum and to evaluate the quality of medicinal materials from different habitats. The method was established with high performance liquid chromatography(HPLC) and the gradient elution was performed with the mobile phase of acetonitrile-methanol-0.2% phosphoric acid solution at a column temperature of 35 ℃, an injection volume of 15 µL, and a flow rate of 0.6 mL·min~(-1). The detection wavelength was set as 215 nm. With rosmarinic acid as the internal reference, the relative correction factors and the content of other 6 components were calculated. The results were compared with those obtained with the external standard method. The results showed that the samples from Huangzhong county, Qinghai province had the best quality, with the highest content of p-hydroxybenzoic acid, cosmosiin, rosmarinic acid, oleanolic acid, and ursolic acid(9.29, 12.14, 6.02, 3.11, 17.67 mg·g~(-1) respectively). The samples from Chaya county, Tibet autonomous region ranked the second, with the highest content of betulin and betulinic acid(15.53, 7.17 mg·g~(-1), respectively). The method is accurate, reliable, and repeatable and suitable for the simultaneous determination of multiple components in D. tanguticum. The content of functional components varied in the samples from different producing areas and can be used as the indicator for the quality evaluation of medicinal materials.

The Molecular Regulatory Mechanism in Multipotency and Differentiation of Wharton's Jelly Stem Cells.

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are isolated from Wharton's jelly tissue of umbilical cords. They possess the ability to differentiate into lineage cells of three germ layers. WJ-MSCs have robust proliferative ability and strong immune modulation capacity. They can be easily collected and there are no ethical problems associated with their use. Therefore, WJ-MSCs have great tissue engineering value and clinical application prospects. The identity and functions of WJ-MSCs are regulated by multiple interrelated regulatory mechanisms, including transcriptional regulation and epigenetic modifications. In this article, we summarize the latest research progress on the genetic/epigenetic regulation mechanisms and essential signaling pathways that play crucial roles in pluripotency and differentiation of WJ-MSCs.

MicroRNA-16 inhibits the lipopolysaccharide-induced inflammatory response in nucleus pulposus cells of the intervertebral disc by targeting TAB3.

INTRODUCTION: A variety of inflammatory mediators are produced by the degenerative human intervertebral disc (IVD) tissues spontaneously, suggesting their role in the development of intervertebral disc degeneration (IDD). Our present study was designed to investigate the regulatory effect of microRNA-16 (miR-16) on the lipopolysaccharide (LPS)-induced inflammatory response in nucleus pulposus (NP) cells of the IVD. MATERIAL AND METHODS: NP cells were treated with LPS to induce inflammatory responses. The expression of miRNA and genes was determined by qRT-PCR. Western blot and an ELISA kit were used to detect the proteins and protein expression, respectively. A dual luciferase reporter assay was applied to identify the correlation between a miRNA and a gene, and to test nuclear factor-κB (NF-κB) activity. RESULTS: The results suggested that miR-16 positively regulated the mRNA and protein expression of extracellular matrix (ECM) genes (including aggrecan and collagen II) in NP cells, while it was negatively correlated with ECM degrading enzymes (including MMP3, MMP13, ADAMTS4, ADAMTS5) and related genes of nitric oxide (NO) reaction. Further studies revealed that miR-16 could oppositely regulate NF-κB and MAPK pathways by directly mediating their upstream gene TAB3. CONCLUSIONS: Our study suggested that, in NP cells of the IVD, miR-16 could exert inhibitory effects on the LPS-induced inflammatory response through NF-κB and MAPK pathways by directly mediating TAB3. In this way, miR-16 would play a protective role against LPS-induced IDD and inflammation. Therefore, miR-16 may be a novel therapeutic target for the inhibit of the ECM in the IVD.

MiR-214 Regulates the Human Hair Follicle Stem Cell Proliferation and Differentiation by Targeting EZH2 and Wnt/ß-Catenin Signaling Way In Vitro.

miR-214 plays a major role in the self-renewal of skin tissue. However, whether miR-214 regulates the proliferation and differentiation of human hair follicle stem cells (HFSCs) is unknown. Primary HFSCs were isolated from human scalp skin tissue, cultured, and identified using flow cytometry. An miR-214 mimic and inhibitor were constructed for transfection into HFSCs. The MTS and colony formation assays examined cell proliferation. Immunofluorescence detected the localization and expression levels of TCF4, ß-catenin, and differentiation markers. Luciferase reporter and TOP/FOP Flash assays investigated whether miR-214 targeted EZH2 and regulated the Wnt/ß-catenin signaling pathway. Western blot determined the expression levels of enhancer of zeste homolog 2 (EZH2), Wnt/ß-catenin signaling-related proteins, and HFSC differentiation markers in cells subjected to miR-214 transfection. miR-214 expression was remarkably decreased during the proliferation and differentiation of HFSCs into transit-amplifying (TA) cells. Downregulation of miR-214 promotes the proliferation and differentiation of HFSCs. Overexpression of miR-214 led to decreased expression of EZH2, ß-catenin, and TCF-4, whereas downregulation of miR-214 resulted in increased expression of EZH2, ß-catenin, and TCF-4 as well as TA differentiation markers. Immunofluorescence assay revealed that inhibiting miR-214 triggered the entry of ß-catenin and TCF-4 into the nucleus. The luciferase reporter and TOP/FOP Flash assays demonstrated that miR-214 directly targets EZH2 and affects Wnt/ß-catenin signaling. The miR-214/EZH2/ß-catenin axis could be considered a candidate target in tissue engineering and regenerative medicine for HFSCs.