Targeting QKI-7 in vivo restores endothelial cell function in diabetes.

Nature communications (2020-08-01)
Chunbo Yang, Magdalini Eleftheriadou, Sophia Kelaini, Thomas Morrison, Marta Vilà González, Rachel Caines, Nicola Edwards, Andrew Yacoub, Kevin Edgar, Arya Moez, Aleksandar Ivetic, Anna Zampetaki, Lingfang Zeng, Fiona L Wilkinson, Noemi Lois, Alan W Stitt, David J Grieve, Andriana Margariti
ABSTRACT

Vascular endothelial cell (EC) dysfunction plays a key role in diabetic complications. This study discovers significant upregulation of Quaking-7 (QKI-7) in iPS cell-derived ECs when exposed to hyperglycemia, and in human iPS-ECs from diabetic patients. QKI-7 is also highly expressed in human coronary arterial ECs from diabetic donors, and on blood vessels from diabetic critical limb ischemia patients undergoing a lower-limb amputation. QKI-7 expression is tightly controlled by RNA splicing factors CUG-BP and hnRNPM through direct binding. QKI-7 upregulation is correlated with disrupted cell barrier, compromised angiogenesis and enhanced monocyte adhesion. RNA immunoprecipitation (RIP) and mRNA-decay assays reveal that QKI-7 binds and promotes mRNA degradation of downstream targets CD144, Neuroligin 1 (NLGN1), and TNF-α-stimulated gene/protein 6 (TSG-6). When hindlimb ischemia is induced in diabetic mice and QKI-7 is knocked-down in vivo in ECs, reperfusion and blood flow recovery are markedly promoted. Manipulation of QKI-7 represents a promising strategy for the treatment of diabetic vascular complications.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
D-(+)-Glucose, powder, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for plant cell culture, ≥99.5%
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Gelatin solution, Type B, 2% in H2O, tissue culture grade, BioReagent, suitable for cell culture
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Forskolin, from Coleus forskohlii, ≥98% (HPLC), powder
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CHIR99021, ≥98% (HPLC)
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DPX Mountant for histology, slide mounting medium
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Magna RIP® RNA-Binding Protein Immunoprecipitation Kit, RNA Immunoprecipitation (RIP) Kit containing all necessary reagents to perform 12 individual RNA-binding protein immunoprecipitation (RIP) reactions using protein A/G magnetic beads.
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p-Xylene-bis(N-pyridinium bromide), ≥95% (TLC)
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Human TSG-6 ELISA Kit, for cell culture supernatants, plasma, and serum samples