LncRNA MALAT1 Promotes OGD-Induced Apoptosis of Brain Microvascular Endothelial Cells by Sponging miR-126 to Repress PI3K/Akt Signaling Pathway

Objective: Angiogenesis led by brain microvascular endothelial cells (BMECs) contributes to the remission of brain injury after brain ischemia reperfusion. In this study, we investigated the effects of hydroxysafflor yellow A(HSYA) on angiogenesis of BMECs injured by OGD/R via SIRT1-HIF-1α-VEGFA signaling pathway. Methods: The OGD/R model of BMECs was established in vitro by OGD for 2h and reoxygenation for 24h. At first, the concentrations of vascular endothelial growth factor (VEGF), Angiopoietin (ang) and platelet-derived growth factor (PDGF) in supernatant were detected by ELISA, and the proteins expression of VEGFA, Ang-2 and PDGFB in BMECs were tested by western blot; the proliferation, adhesion, migration (scratch healing and transwell) and tube formation experiment of BMECs; the expression of CD31 and CD34 were tested by immunofluorescence staining. The levels of sirtuin1(SIRT1), hypoxia-inducible factor-1α (HIF-1α), VEGFA mRNA and protein were tested. Results: HSYA up-regulated the levels of VEGF, Ang and PDGF in the supernatant of BMECs under OGD/R, and the protein expression of VEGFA, Ang-2 and PDGFB were increased; HSYA could significantly alleviate the decrease of cell proliferation, adhesion, migration and tube formation ability of BMECs during OGD/R; HSYA enhanced the fluorescence intensity of CD31 and CD34 of BMECs during OGD/R; HSYA remarkably up-regulated the expression of SIRT1, HIF-1α, VEGFA mRNA and protein after OGD/R, and these increase decreased after SIRT1 was inhibited. Conclusion: SIRT1-HIF-1α-VEGFA signaling pathway is involved in HSYA improves angiogenesis of BMECs injured by OGD/R.

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LncRNA MALAT1 up-regulates VEGF-A and ANGPT2 to promote angiogenesis in brain microvascular endothelial cells against oxygen–glucose deprivation via targetting miR-145

Bioscience Reports ◽

10.1042/bsr20180226 ◽

2019 ◽

Vol 39 (3) ◽

Cited By ~ 29

Author(s):

Lanfen Ren ◽

Chunxia Wei ◽

Kui Li ◽

Zuneng Lu

Keyword(s):

Endothelial Cells ◽

Glucose Deprivation ◽

Luciferase Assay ◽

Microvascular Endothelial Cells ◽

Oxygen Glucose Deprivation ◽

Brain Microvascular Endothelial Cells ◽

Qrt Pcr ◽

Lncrna Malat1 ◽

Microvascular Endothelial

Abstract Stroke is one of the leading causes of death and long-term disability around the world. Angiogenesis is supposed to protect brain microvascular endothelial cells (BMECs) from oxidative and ischemic stress. Previous studies indicated that interaction between metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and miR-145 was involved in myocardial ischemia reperfusion, suggesting MALAT1 and miR-145 were also mediated with the progress of angiogenesis and cell migration in oxygen–glucose deprivation (OGD)-induced BMECs. The present study aimed to investigate the functional roles of MALAT1 in regulating miR-145 and its downstream pro-angiogenesis factors, vascular endothelial growth factor (VEGF)-A and Angiopoietin-2 (ANGPT2) during the progress of angiogenesis in OGD-induced BMECs. An in vitro OGD model was employed in mouse BMECs to mimic brain hypoxic and ischemic conditions; MTT was used to determine cell viability. qRT-PCR was used to determine the expression of long non-coding RNA (lncRNA)-MALAT1 and miR-145 under OGD conditions; in vitro tube formation assay was used to investigate angiogenic effect of MALAT1 and miR-145. The relationship between lncRNA-MALAT1/miR-145 and miR-145/VEGF-A/ANGPT2 was evaluated by qRT-PCR and Western blot, and direct binding was assessed using dual luciferase assay. Results showed that the levels of lncRNA-MALAT1 and miR-145 were up-regulated in OGD-induced BMECs. miR-145 functioned as an anti-angiogenic and pro-apoptotic factor in OGD treated BMECs via down-regulating VEGF-A and ANGPT2 directly. While lncRNA-MALAT1 enhanced the expressions of VEGF-A and ANGPT2 by targetting miR-145 to promote angiogenesis and proliferation of BMECs under OGD conditions. Our present study revealed the inhibitory functions of miR-145 on angiogenesis through direct targetting on VEGF-A and ANGPT2 for the first time and proved the protective role of lncRNA-MALAT1 for BMECs under OGD conditions through the direct regulation of miR-145.

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LFA1 Mediated Attachment of Primary Human Monocytes to Activated Brain Microvascular Endothelial Cells Is Regulated by SDF-1α through the SRC Family Kinase Lyn; Potential Involvement of This Signaling Pathway in HIV-Associated Dementia.

Blood ◽

10.1182/blood.v110.11.516.516 ◽

2007 ◽

Vol 110 (11) ◽

pp. 516-516

Author(s):

Mobeen Malik ◽

Ying-Yu Chen ◽

Martha F. Kienzle ◽

Ronald G. Collman ◽

Andrzej Ptasznik

Keyword(s):

Endothelial Cells ◽

Signaling Pathway ◽

Intracellular Signaling ◽

Microvascular Endothelial Cells ◽

Brain Microvascular Endothelial Cells ◽

Human Monocytes ◽

Src Family Kinase ◽

Down Regulation ◽

Microvascular Endothelial ◽

Monocyte Adherence

Abstract Infiltration of activated monocytes into the brain of HIV-infected patients is a prerequisite for the development of HIV-associated dementia (HAD). The chemokine stromal derived factor-1α (SDF-1α) is expressed at increased levels in the central nervous system (CNS) of HAD patients and elicits chemotaxis and other cellular effects through its receptor CXCR4. In this project, we investigated the intracellular signaling pathway by which SDF-1α mediates the movement and attachment of monocytes to brain microvascular endothelia, and which may contribute to their infiltration into the CNS in HAD. We demonstrated that SDF-1α stimulates migration of primary human monocytes through its receptor CXCR4, and decreases monocyte adherence to surfaces coated with ICAM-1. SDF-1α also decreases monocyte adherence to brain microvascular endothelial cells (BMVEC) activated with the pro-inflammatory cytokines TNF-α or IL-1β, or with recombinant HIV-1 envelope glycoprotein (gp120), which increase endothelial cells expression of ICAM-1. The decreased monocyte adherence was linked to down regulation of the activation-dependent epitope of the β2 integrin LFA-1 which is a ligand for ICAM-1. We then demonstrated that the Src family kinase Lyn is a central modulator of migration and LFA-1-mediated adhesion of SDF-1α-stimulated primary monocytes. Using siRNA knockdown we achieved 80% down regulation of Lyn kinase in human monocytes. Lyn down regulation decreased SDF-1α-mediated migration and prevented its inhibition of monocyte attachment to ICAM-1 coated surfaces and activated BMVEC. These data indicate that in SDF-1α-stimulated primary human monocytes Lyn is a positive regulator of cell migration, and a negative regulator of cell adhesion to BMVEC by inhibiting the ICAM-1 binding activity of the LFA-1 integrin. Thus, CXCR4-triggered inside-out integrin signaling, through Lyn, inhibits adherence and stimulates movement of monocytes towards SDF-1α gradient on BMVEC monolayers. These results provide new insight into the intracellular signaling cascade that controls primary human monocytes movement and attachment at the blood brain barrier.

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