Abstract
Leukemia inhibitory factor (LIF) and leukemia inhibitory factor receptor (Lifr) protect CNS cells, specifically neurons and myelin-sheath oligodendrocytes, in conditions of oxygen-glucose deprivation (OGD). In the case of astrocyte apoptosis resulting from reperfusion injury following hypoxia, the function of the Lifr remains to be fully elucidated. This study established models of in vivo ischemia/reperfusion (I/R) using an in vitro model of OGD to investigate the direct impact of silencing the Lifr on astrocyte apoptosis. Astrocytes harvested from newborn Wistar rats were exposed to OGD. Cell viability and apoptosis levels were determined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and annexin V/propidium iodide (PI) staining assays, respectively. Apoptosis was further investigated by the TdT-mediated dUTP nick-end labelling (TUNEL) assay. A standard western blotting protocol was applied to determine levels of the protein markers Bcl2, Bax, p-Akt/Akt, p-Stat3/Stat3, and p-Erk/Erk. The cell viability assay (MTT) showed that astrocyte viability decreased in response to OGD. Furthermore, blocking RNA to silence the Lifr further reduces astrocyte viability and increases levels of apoptosis as detected by annexin V/PI double staining. Likewise, western blotting after Lifr silencing demonstrated increased levels of the apoptosis-related proteins Bax and p-Erk/Erk and correspondingly lower levels of Bcl2, p-Akt/Akt, and p-Stat/Stat3. The data gathered in these analyses indicate that the Lifr plays a pivotal role in the astrocyte apoptosis induced by hypoxic/low-glucose environments. Further investigation of the relationship between apoptosis and the Lifr may provide a potential therapeutic target for the treatment of neurological injuries.
Highlights
Hypoxic-ischemic encephalopathy (HIE) is known to be a major cause of child mortality and disability, but the processes that lead to neuronal apoptosis in HIE are as yet undefined
Silencing of the LIF receptor (Lifr) in otherwise normal cells led to a slight reduction in cell viability
The link between brain injury resulting from ischemia and astrocyte damage is widely recognised [23, 24], and it is proposed here that protecting astrocytes in this environment from further apoptotic damage and death may be pivotal in partially protecting brain tissue from ischemic injury and improving postischemic functionality
Summary
Hypoxic-ischemic encephalopathy (HIE) is known to be a major cause of child mortality and disability, but the processes that lead to neuronal apoptosis in HIE are as yet undefined. Given the pivotal role of astrocytes in CNS metabolism and glutamate balance, their death or disruption results in damage to the CNS and neuronal cell death [7, 8]. Early astrocyte death due to hypoxia and ischemia leads to an interruption in key mechanisms, generating greater neuronal apoptosis, which causes larger lesions and disrupts synaptogenesis [11, 12]. In light of their critical role, it is clear that astrocytes offer a robust therapeutic target to minimise damage resulting from cerebral HI
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
