JNK inhibitor alleviates apoptosis of fetal neural stem cells induced by emulsified isoflurane

Abstract

Isoflurane can provide both neuroprotection and neurotoxicity in various culture models and in rodent developing brains. Emulsified Isoflurane (EI) is an emulsion formulation of isoflurane, while its underlying molecular mechanism of developemental nerve toxicity largely remains unclear. We hypothesized that EI induced fetal neural stem cells (FNSCs) apoptosis, endoplasmic reticulum (ER) stress and c-Jun N-terminal kinase (JNK) activation.FNSCs were isolated from the cortex of SD rats during 14 days of gestation. The cell viability, cell apoptotic rates and the expression of apoptosis-related protein Caspase3, inositol requiring enzyme 1 (IRE1), poly (adenosine diphosphate-ribose) polymerase (PARP), Bax, Bcl-2, JNK, p-JNK and XBP1 were determined. Specific inhibition was performed by siRNA-targeting of JNK in FNSCs. EI could increase the p-JNK, JNK and caspase3 protein expression, the JNK pathway was activated by EI, and EI-induced apoptosis was blocked by inhibiting JNK pathway with SP600125 or JNK-small interfering RNA (siRNA), EI enhanced the level of IRE1, PARP, Bax/Bcl-2 and XBP1, which led FNSCs to apoptosis and ER stress. Meanwhile, dilatation of the ER lumens in FNSCs treated by EI for 24 h was significant. Green fluorescent protein (GFP) positive cell ratios were significantly decreased by FNSCs transfecting with JNK gene silencing. JNK was efficiently silenced in siRNA-JNK1 group.The results provided in-vitro evidence which supports that the underlying mechanisms of EI-induced apoptosis are the induction of ER stress and sequent JNK activation. Together, these data suggest that JNK inhibiting might be applied for improving therapeutic outcomes in anesthestics-induced neurotoxicity.Highlights:1. Prolonged treatment with high-dose EI decreased the survival level of FNSCs by inducing apoptosis and inhibiting proliferation via the JNK signaling pathway.2. EI induced ER stress and sequent JNK activation.3. JNK inhibiting might be applied for improving therapeutic outcomes in anesthestics-induced neurotoxicity

Research progress on molecular mechanisms of general anesthetic-induced neurotoxicity and cognitive impairment in the developing brain

“…c-Jun N-terminal kinases (JNKs) belong to the mitogen-activated protein kinase family (MAPK) and are involved in apoptosis. The study found that JNKs and their downstream c-Jun were involved in the neurotoxicity of sevoflurane in the neonatal brain; meanwhile, up-regulation of HIPK2, JNK, and c-Jun was observed in hippocampal neurons of mice exposed to sevoflurane, continued until adulthood ( 14 ), inhibition of JNK found that mice can restore normal neurodevelopment and cognitive function ( 14 , 15 ), but activation of this signaling pathway can induce neuronal apoptosis ( 16 ), which may be linked to its upregulation of Connexin-43, and its increase can lead to cognitive dysfunction ( 17 ). And when JNK antagonists were given to these newborn mice, it was found that the expression of HIPK2 was not affected ( 14 ), so JNKs/c-Jun signaling pathway may be directly induced by general anesthetics, but not related to the presence of HIPK2.…”

Research progress on the effects and mechanisms of anesthetics on neural stem cells

“…These changes may have detrimental effects on cognition after isoflurane anesthesia, 22,65 the magnitude of which is clearly age‐dependent 66 . The JNK inhibitor alleviates emulsified isoflurane‐induced apoptosis of fetal NSCs 67 . l ‐Theanine and simvastatin attenuate isoflurane‐induced neurogenetic damage and neurocognitive deficits in developing rats' brains through upregulation of the Akt/GSK‐3β signaling pathway 68,69 …”

“… 66 The JNK inhibitor alleviates emulsified isoflurane‐induced apoptosis of fetal NSCs. 67 l ‐Theanine and simvastatin attenuate isoflurane‐induced neurogenetic damage and neurocognitive deficits in developing rats' brains through upregulation of the Akt/GSK‐3β signaling pathway. 68 , 69 …”

Neuroprotective properties of the C-Jun N-terminal kinase (JNK) inhibitor in hypoxic hypoxia

“…При ýтом ключевая роль в предупреждении им развития нарушений деятельности ЦНС и их компенсации, очевидно, принадлежит сохранению способности нервной ткани к репарации, связанной с обеспечением адекватного функционирования резидентных нейральных СК головного мозга [5,6]. В основе реализации данного механизма лежит, по-видимому, не только прямое стимулирующее влияние блокады JNK-опосредованного сигналинга в отношении прогрессии клеточного цикла родоначальных ýлементов, но и требующее дальнейшего ýкспериментального подтверждения -торможение процессов их JNK-зависимого апоптоза [13][14][15].…”