Brain microvascular endothelial cell-derived exosomes transmitting circ_0000495 promote microglial M1-polarization and endothelial cell injury under hypoxia condition.
Xiao-Li MinWen-Ji JiaLi GuoRui JingXiao-Hong ZhaoJia-Yi HuXu-Hui LiWei LiuTao WangXing-Kui DouPublished in: FASEB journal : official publication of the Federation of American Societies for Experimental Biology (2024)
Human brain microvascular endothelial cells (HBMVECs) and microglia play critical roles in regulating cerebral homeostasis during ischemic stroke. However, the role of HBMVECs-derived exosomes in microglia polarization after stroke remains unknown. We isolated exosomes (Exos) from oxygen glucose deprivation (OGD)-exposed HBMVECs, before added them into microglia. Microglia polarization markers were tested using RT-qPCR or flow cytometry. Inflammatory cytokines were measured with ELISA. Endothelial cell damage was assessed by cell viability, apoptosis, apoptosis-related proteins, oxidative stress, and angiogenic activity using CCK-8, flow cytometry, western blot, ELISA, and endothelial tube formation assay, respectively. We also established middle cerebral artery occlusion (MCAO) mice model to examine the function of circ_0000495 on stroke in vivo. Our study found that HBMVECs-Exos reduced M2 markers (IL-10, CD163, and CD206), increased M1 markers (TNF-α, IL-1β, and IL-12), CD86-positive cells, and inflammatory cytokines (TNF-α and IL-1β), indicating the promotion of microglial M1-polarization. Microglial M1-polarization induced by HBMVECs-Exos reduced viability and promoted apoptosis and oxidative stress, revealing the aggravation of endothelial cell damage. However, circ_0000495 silencing inhibited HBMVECs-Exos-induced alterations. Mechanistically, circ_0000495 adsorbed miR-579-3p to upregulate toll-like receptor 4 (TLR4) in microglia; miR-579-3p suppressed HBMVECs-Exos-induced alterations via declining TLR4; furthermore, Yin Yang 1 (YY1) transcriptionally activated circ_0000495 in HBMVECs. Importantly, circ_0000495 aggravated ischemic brain injury in vivo via activating TLR4/nuclear factor-κB (NF-κB) pathway. Collectively, OGD-treated HBMVECs-Exos transmitted circ_0000495 to regulate miR-579-3p/TLR4/NF-κB axis in microglia, thereby facilitating microglial M1-polarization and endothelial cell damage.
Keyphrases
- inflammatory response
- endothelial cells
- toll like receptor
- oxidative stress
- nuclear factor
- high glucose
- lps induced
- diabetic rats
- flow cytometry
- lipopolysaccharide induced
- induced apoptosis
- brain injury
- neuropathic pain
- cell cycle arrest
- subarachnoid hemorrhage
- ischemia reperfusion injury
- cerebral ischemia
- middle cerebral artery
- mesenchymal stem cells
- endoplasmic reticulum stress
- cell death
- signaling pathway
- stem cells
- dna damage
- vascular endothelial growth factor
- pi k akt
- atrial fibrillation
- high throughput
- insulin resistance
- blood pressure
- type diabetes
- monoclonal antibody
- nk cells
- resting state
- metabolic syndrome
- multiple sclerosis
- internal carotid artery