Toll-like receptor signalling pathways regulate hypoxic stress induced fibroblast growth factor but not vascular endothelial growth factor-a in human microvascular endothelial cells

Akhtar, Rukhsar, Tahir, Husain, Stewart, Elizabeth, Wei, Ruoxin, Mohammed, Imran ORCID: https://orcid.org/0000-0002-8412-0768 and Amoaku, Winifred M. 2021. Toll-like receptor signalling pathways regulate hypoxic stress induced fibroblast growth factor but not vascular endothelial growth factor-a in human microvascular endothelial cells. International Journal of Translational Medicine 1 (1) , pp. 25-38. 10.3390/ijtm1010003

PDF - Published Version Available under License Creative Commons Attribution. Download (2MB)

Abstract

Retinal diseases are the leading causes of irreversible blindness worldwide. The role of toll-like receptor (TLR) signalling mechanisms (MyD88 and TRIF) in the production of pro-angiogenic growth factors from human microvascular endothelial cells (HMEC-1) under hypoxic stress remains unexplored. HMEC-1 was incubated under normoxic (5% CO2 at 37 °C) and hypoxic (1% O2, 5% CO2, and 94% N2; at 37 °C) conditions for 2, 6, 24, and 48 h, respectively. For TLR pathway analysis, HMEC-1 was pre-treated with pharmacological inhibitors (Pepinh-MyD88 and Pepinh-TRIF) and subjected to normoxia and hypoxia conditions. Gene and protein expressions of vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor (FGF-2), hypoxia inducible factor 1-alpha (HIF1-α) were performed using quantitative polymerase chain reaction (qPCR), ELISA, and Western blot methodologies. Levels of TLR3 and TLR4 were analysed by flow cytometry. Under hypoxia, levels of VEGF-A and FGF-2 were elevated in a time-dependent fashion. Inhibition of MyD88 and TRIF signalling pathways decreased FGF-2 levels but failed to modulate the secretion of VEGF-A from HMEC-1. Blocking a known regulator, endothelin receptor (ETR), also had no effect on VEGF-A secretion from HMEC-1. Overall, this study provides the proof-of-concept to target TLR signalling pathways for the management of blinding retinal diseases.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Optometry and Vision Sciences
Publisher:	MDPI
Date of First Compliant Deposit:	10 November 2022
Date of Acceptance:	12 May 2021
Last Modified:	20 May 2023 22:07
URI:	https://orca.cardiff.ac.uk/id/eprint/153247

Actions (repository staff only)

Edit Item