Humanin analogue, S14G-humanin, has neuroprotective effects against oxygen glucose deprivation/reoxygenation by reactivating Jak2/Stat3 signaling through the PI3K/AKT pathway

Abstract

Abstract. Stroke, characterized by a disruption of blood supply to the brain, is a major cause of morbidity and mortality worldwide. Although humanin, a 24-amino acid polypeptide, has been identified to have multiple neuroprotective functions, the level of humanin in plasma has been demonstrated to decrease with age, which likely limits the effects against stroke injury. A potent humanin analogue, S14G-humanin (HNG), generated by replacement of Ser14 with glycine, has been demonstrated to have 1,000-fold stronger biological activity than humanin. The present study established an in vitro oxygen glucose deprivation/reoxygenation (OGD/R) model using SH-SY5Y neuroblastoma cells to mimic the in vivo ischemia/reperfusion injury in stroke. Adding HNG (0-10 µg/l) to SH-SY5Y cells to different extents blocked OGD/R-induced reduction of cell viability and antioxidative capacity, as well as decreased the elevated apoptosis rate induced by OGD/R, with the most evident effects at 1 µg/l HNG. Janus kinase 2 (Jak2)/signal transducer and activator of transcription 3 (Stat3) signaling was attenuated in OGD/R processes, yet reactivated with HNG treatment. FLLL32 (5 µM), a specific inhibitor of the signal, abolished effects of HNG on anti-apoptosis and antioxidation in OGD/R processes. Co-treatment with HNG and FLLL32 failed to interrupt upregulation of cytochrome c, B-cell lymphoma 2-associated X protein and cleaved caspase-3 provoked by OGD/R. Similar to FLLL32, Jak2/Stat3 signaling activated by HNG was also repressed by inhibitor of phosphoinositide 3-kinase (PI3K; 10 µM LY294002) or protein kinase B (AKT; 5 µM MK-2206 2HCl). These data collectively indicated that HNG has neuroprotective effects against OGD/R by reactivating Jak2/Stat3 signaling through the PI3K/AKT pathway, suggesting that HNG may be a promising agent in the management of stroke.

In Vitro Oxygen-Glucose Deprivation-Induced Stroke Models with Human Neuroblastoma Cell- and Induced Pluripotent Stem Cell-Derived Neurons

“…In our study, cytotoxicity and apoptosis of SH-SY5Y-neurons were increased, and viability SH-SY5Y-neurons was decreased after OGD followed by 24 or 72 h of reperfusion. This is in line with previous studies in nondifferentiated SH-SY5Y cells showing decreased cell viability and activation of apoptosis after OGD [ 53 , 56 ]. Gao et al showed that cell viability decreases, and the apoptosis rate increases after 16 h of OGD and 9 h of reperfusion.…”

Resveratrol provides neuroprotection by regulating the JAK2/STAT3/PI3K/AKT/mTOR pathway after stroke in rats

“…To Figureure out the role of the PI3K pathway following cerebral I/R, rats in the Res30 + LY294002 group were pretreated with LY294002 (Selleckchem, Houston, USA), an effective inhibitor of PI3K, as previously described. 20 Prior to surgery, dimethyl sulfoxide (DMSO) and ethanol (ETOH) were used as solvents for LY294002, dissolved to a concentration of 20 mM. Animals were anesthetized (7% chloral hydrate, 350 mg/kg, IP) and fixed on a stereotaxic apparatus.…”

MANF attenuates neuronal apoptosis and promotes behavioral recovery via Akt/MDM‐2/p53 pathway after traumatic spinal cord injury in rats

“…The antiapoptotic mechanism of MANF was investigated in vitro. SH-SY5Y cells were randomly divided into five groups: control (no treatment), injury 1 vehicle, injury 1 MANF (4 lg/ mL) [24], injury 1 MK2206 (5 lmol/mL), and injury 1 MANF 1 MK2206 [25]. After establishing the cell model and treatment, the cells were cultured for 48 h [24]; after which they were divided into 18 parts for flow cytometry (N 5 6), MTT assay (N 5 6), and trypan blue (TB) staining (N 5 6) to assess cell apoptosis and viability.…”