HYPOXIC TUBULAR EPITHELIAL CELLS REGULATING ANGIOGENESIS BY RAB7/MMP-2 AXIS

Y YANG1, J WANG2, Z WANG1, X HU1, J CHANG1, J GUAN1, Y ZHANG1, L LI1, P CHEN3

1Department Of Pathology And Pathophysiology, Medical School, Southeast University, Nanjing, China, 2Department Of  Andrology, Nanjing Drum Tower hospital,Nanjing University, Nanjing, China, 3Institute of Nephrology, The Affiliated Zhongda Hospital, Southeast University, Nanjing, China

Background: Renal hypoxia is intricately linked to persisting peritubular capillary rarefaction in progressive chronic kidney disease (CKD), which is mainly due to the dysregulated angiogenesis. It is known to all that the vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) are released in the form of proenzyme and activated on the surface of cells and they are key factors of angiogenesis. Rab7 has been shown to be one of the molecules shared by autophagy and endocytosis, which are not only the main factors of cell membrane remodeling, but also play decisive roles in regulation of transmembrane signal transduction. It is unclear whether the Rab7 regulates the activation of MMP-2 in renal tubular epithelial cells (TECs) and thereby interfering with angiogenesis.
Aim: In order to explore the relationship between the expression of Rab7 in TECs and angiogenesis.
Methods:
1. Cell proliferation experiment
2. Cell migration experiment
3. Endothelial tubular experiment
4. Immunofluorescence experiment
5. Gelatinase spectrum experiment
6. ELISA experiment
7. Westernblot experiment
8. Real-time fluorescence quantitative PCR experiment
9. Sirius red staining
10. Immunohistochemistry experiment
11. Transmission ElectronMicroscope(TEM)
Results: The results showed that hypoxia promoted the expression of Rab7 and VEGF in TECs, and the expression levels of Rab7 were positively correlated with autophagy, endocytosis related with molecules (HIF-1α, LC3II and Caveolin-1) and the activity of MMP-2 related with regulatory molecules such as reversion-inducing-cysteine-rich protein with kazal motifs (RECK), negative correlation with membrane-type 1 MMP (MT1-MMP or MMP-14) on the membrane of TECs. In addition, the up-regulation of the expression of Rab7 inhibited the activity of MMP-2 and proliferation and cyclization of endothelial cells, and the inhibitor of MMP-2 partially blocked the effects of Rab7 on angiogenesis. Furthermore, the similar data were also obtained in the fibrosis kidney tissues of mice.
Conclusion: Taken together, our study demonstrated that hypoxic TECs regulated angiogenesis by Rab7/MMP-2 axis.


Biography:

Yang Yiqiong, female, Han Nationality, was born in Liaocheng, Shandong Province in October 1990. She is now a doctoral candidate in internal Medicine, Medical College of Southeast University, and her supervisor is Professor Chen Pingsheng.

School and work experience

2009.09 — 2014.07 Binzhou Medical College, bachelor’s degree in clinical Medicine

2014.09 —  2017.06 Southeast University, master degree in internal medicine, master degree in Medicine

2017.07 – now Doctoral candidate in internal Medicine, School of Medicine, Southeast University

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