Endothelial precursor cells stimulate pericyte‐like coverage of bone marrow‐derived mesenchymal stem cells through platelet‐derived growth factor‐ BB induction, which is enhanced by substance P

Zhang, Mingzi,Ahn, Woosung,Kim, Sumin,Hong, Hyun Sook,Quan, Chengshi,Son, Youngsook John Wiley & Sons Ltd. 2017 Microcirculation Vol.24 No.8

<P><B>Abstract</B></P><P><B>Objective</B></P><P>The aim of this study was to evaluate the angiogenicity of a combination of BM‐EPCs and BM‐MSCs in vitro in the presence of SP and its working mechanism.</P><P><B>Methods</B></P><P>BM‐MSCs and BM‐EPCs were cocultured with or without SP. ELISA and RT‐PCR were performed to detect angiogenic factors such as VEGF and PDGF‐BB. N‐cadherin was detected by Western blot analysis. The tubular network‐forming ability was evaluated by a Matrigel tube‐forming assay.</P><P><B>Results</B></P><P>BM‐EPCs coculture with BM‐MSCs strongly stimulated the recruitment of BM‐MSCs onto the BM‐EPC‐generated endothelial tubular network. Upon SP treatment, endothelial branching point, tubule length, and tubular recruitment of BM‐MSCs were further increased and stabilized. The coculture of BM‐EPCs and BM‐MSCs synergistically stimulated expression of VEGF, VEGF receptor, N‐cadherin, and PDGF‐BB, all of which were further enhanced by SP treatment. Blockade of PDGF‐BB by its functional blocking antibodies markedly reduced the BM‐MSC incorporation into the endothelial tubules. SP‐pretreated BM‐MSCs were preferentially incorporated into the preformed BM‐EPC tubular network.</P><P><B>Conclusions</B></P><P>BM‐EPCs along with SP promote the pericyte‐like coverage of BM‐MSCs on endothelial tubules possibly through the induction of PDGF‐BB.</P>

Affection-enhanced Personalized Question Recommendation in Online Learning

Mingzi Chen,Xin Wei,Xuguang Zhang,Lei Ye 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.12

With the popularity of online learning, intelligent tutoring systems are starting to become mainstream for assisting online question practice. Surrounded by abundant learning resources, some students struggle to select the proper questions. Personalized question recommendation is crucial for supporting students in choosing the proper questions to improve their learning performance. However, traditional question recommendation methods (i.e., collaborative filtering (CF) and cognitive diagnosis model (CDM)) cannot meet students' needs well. The CDM-based question recommendation ignores students' requirements and similarities, resulting in inaccuracies in the recommendation. Even CF examines student similarities, it disregards their knowledge proficiency and struggles when generating questions of appropriate difficulty. To solve these issues, we first design an enhanced cognitive diagnosis process that integrates students’ affection into traditional CDM by employing the non-compensatory bi-dimensional item response model (NCB-IRM) to enhance the representation of individual personality. Subsequently, we propose an affection-enhanced personalized question recommendation (AE-PQR) method for online learning. It introduces NCB-IRM to CF, considering both individual and common characteristics of students’ responses to maintain rationality and accuracy for personalized question recommendation. Experimental results show that our proposed method improves the accuracy of diagnosed student cognition and the appropriateness of recommended questions.

Induction of Mesenchymal to Epithelial Transition of Circulating Mesenchymal Stem Cells by Conditioned Medium of Injured Cornea

안우성,홍현숙,Mingzi Zhang,정은경,손영숙 한국조직공학과 재생의학회 2013 조직공학과 재생의학 Vol.10 No.2

We previously reported that substance-P (SP) mobilized mesenchymal stem cells (MSCSP) from bone marrow and recruited them to the injured site, which then participated in wound healing process by incorporation into the corneal epithelium in a rabbit alkali burn model. In the present study, we investigated if the injured microenvironment could stimulate the recruited MSCSP to lose their mesenchymal phenotype and then acquire epithelial phenotype or not. Especially, we focused on the effects of secreted soluble tissue factors of wound microenvironment in the rat cornea wound model. Priming the circulating MSCSP with conditioned medium of the injured tissue at day 5 elicited morphological and molecular changes similar to those noted during mesenchymal to epithelial transition (MET),which was accompanied by the reduction of alpha-smooth muscle actin (α-SMA), a typical mesenchymal marker,and induction of E-cadherin, a typical epithelial marker. Furthermore, these primed MSCSP rearranged their actin cytoskeletal system from distinct actin stress fiber projection to the cell-to-cell-contact-enriched actin microfilament. The primed cells also had increased survival in keratinocyte growth medium (KGM). In conclusion, MSCSP could be differentiated in vitro to the epithelial cells under the injured microenvironment, which may also occur in vivo during tissue repair.

Anomalous Ferromagnetism and Electron Microscopy Characterization of High-Quality Neodymium Oxychlorides Nanocrystals

Xinliang Zheng,Juan Feng,Jiarui Zhang,Hongna Xing,Jiming Zheng,Mingzi Wang,Yan Zong,Jintao Bai,Xinghua Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.3

High-quality neodymium oxychlorides nanocrystals with cubic shape were synthesized by a nonhydrolytic thermolysis route. The morphology and crystal structure of the neodymium oxychlorides nanocubes were characterized by transmission electron microscopy at the nanoscale. Transmission electron microscope (TEM) image shows that the neodymium oxychlorides nanocrystals are nearly monodispersed with cube-like shape. X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns of numerous neodymium oxychlorides nanocubes suggest a pure crystal phase with tetragonal PbFCl matlockite structure. HRTEM image of individual neodymium oxychlorides nanocubes indicate that each nanocubes have a singlecrystalline nature with high quality. Unlike the anti-ferromagnetism of the bulk, the neodymium oxychlorides nanocubes show clearly anomalous ferromagnetic characteristic at room temperature. This finding provides a new platform for the exploration of diluted magnetic semiconductors, rare earth-based nanomaterials and so on.

Substance P reduces apoptotic cell death possibly by modulating the immune response at the early stage after spinal cord injury

Jiang, Mei Hua,Lim, Ji Eun,Chi, Guang Fan,Ahn, Woosung,Zhang, Mingzi,Chung, Eunkyung,Son, Youngsook Wolters Kluwer Health | Lippincott Williams Wilkin 2013 NEUROREPORT - Vol.24 No.15

Previously, we have reported that substance P (SP) enhanced functional recovery from spinal cord injury (SCI) possibly by the anti-inflammatory modulation associated with the induction of M2-type macrophages at the injured lesion. In this study, we explored the cytokine expression profiles and apoptotic cell death in the lesion site of the SCI after an immediate intravenous injection of SP. SP injection increased the levels of interleukin-4 (IL-4), IL-6, and IL-10 at day 1 after the SCI approximately by 2-, 9-, and 10-folds when compared with the control SCI, respectively. On the basis of double immunofluorescence staining with IL-10 and CD11b, activated macrophages or microglia expressing IL-10 appeared in the margin of the lesion site at day 1 only after the SP injection. This SP-mediated alteration in the lesion microenvironment was shown to be associated with the lower cell death of neuronal cells at day 1 and oligodendrocytes at day 5 by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, which was also accompanied by a decrease in caspase-3 activation. These findings suggest that SP may reduce the inflammation-induced secondary cell death, possibly through immune modulation at an early stage after the SCI.

Role of Estrogen Receptor-α in the Regulation of Claudin-6 Expression in Breast Cancer Cells

Liu Yafang,Wu Qiong,Ren Yue,Xu Xiaoming,Yu Lina,Zhang Mingzi,Zhang Ting,Li Yulin,Quan Chengshi 한국유방암학회 2011 Journal of breast cancer Vol.14 No.1

Purpose: In our previous studies we showed that upregulating claudin-6 (CLDN6) expression may contribute to preventing breast cancer, and that 17β-estradiol induces a concentration- and time-related effect on CLDN6 mRNA and protein expression in MCF-7 cells. However, the mechanisms of 17β-estradiol regulation of CLDN6 are still unclear. We determined the role of estrogen receptors in the regulation of CLDN6 expression in human breast cancer tissues and a cell line. Methods: CLDN6, estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) expression in breast cancer tissues were examined using immunohistochemistry. The human breast cancer cell line, MCF-7, which expresses ERα but not ERβ was used. CLDN6 and ERα expression were measured by reverse transcriptase-PCR, Western blotting and immunofluorescent staining. Treatments with propyl pyrazole triol (PPT) and ICI 182, 780 (ICI) were performed. Results: The results revealed that CLDN6 expression was related to ERα in breast cancer tissues (p=0.033). PPT, an ERα-selective ligand, upregulated CLDN6 expression at 10^(-5) mol/L after 24 hours. The effect of PPT on regulating CLDN6 expression in MCF-7 cells was blocked by ICI. Conclusion: These findings suggest that Erα reulates CLDN6 expression in breast cancer tissues and that 17β- estradiol induces CLDN6 expression through an ERα pathway in MCF-7 cells.