To date the underlying mechanism of ropivacaine in inducing

To date, the underlying mechanism of ropivacaine in inducing neurotoxicity remains unclear. Cell death was intimately involved in local-anesthetic neurotoxicity [6,18]. Two classic signaling pathways triggered cell death: the extrinsic pathway and the intrinsic pathway [12]. Our study demonstrated that ropivacaine effectively increased the expression of Fas, which ultimately induced neurogliocyte apoptosis. Numerous studies reported that mitogen-activated protein kinase (MAPK) signals were involved in gene transcription [14,15]. In addition, ropivacaine neurotoxicity was associated with the activation of the MAPK signal [16]. Zhai et al. reported that ropivacaine treatment enhanced the phosphorylation of extracellular regulated protein kinases (p-ERK), which ultimately induced seizures and negative emotions in mice [16]. Our study demonstrated that ropivacaine facilitated the phosphorylation of P38 (p-P38), followed by upregulating the expression of Fas (Fig. 5C). These findings suggest that ropivacaine neurotoxicity was associated with activation of the MAPK signal, but the inconsistent influences of ropivacaine on the downstream signal of MAPK may be context-dependent or cell type–specific, that needs more comprehensive exploration. Previous studies also reported that local-anesthetic neurotoxicity might be associated with mitochondria damage [9,10]. Xing et al. reported that bupivacaine decreased mitochondrial membrane potential and increased reactive oxygen species (ROS) generation in astrocytes [9]. The results from Lucchinetti et al. showed that ropivacaine inhibited mitochondrial respiration and reduced U-104 mg production in MSCs [10]. Consistent with the previous studies, our study demonstrated that ropivacaine significantly decreased the mitochondrial membrane potential. Bax and Bak normally acted on the mitochondrial membrane to promote permeabilization and release of cytochrome c, which was an important signal in the apoptosis cascade [19]. However, Bcl-2 played an important role in promoting cellular survival and inhibiting the actions of Bak and Bax [19]. In the present study, ropivacaine treatment caused the subcellular translocation of Bcl-2 family members and promoted the release of cytochrome c from mitochondria to cytoplasm, which ultimately caused mitochondria-dependent intrinsic apoptosis (Fig. 5C). All these results indicated that mitochondria damage participated in the process of ropivacaine-induced neurotoxicity. Nowadays, numerous studies have focused on reducing local-anesthetic neurotoxicity. Zhai et al. reported that dexmedetomidine dose-dependently attenuated ropivacaine-induced seizures and negative emotions [16]. Foley et al. used a low solubility drug, a drug action enhancer, nanoparticles, and a Thermo-Gel matrix together to yield a delivery system capable of alleviating neurotoxicity from local anesthetics [20]. In the present study, our results demonstrated that the combination of ropivacaine and ralimetinib significantly alleviated the ropivacaine toxicity in neurogliocytes, although other possible side-effects and toxic effects triggered by ropivacaine and ralimetinib could not be ruled out in cell models, which needs to be further tested in animal models.
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Introduction Renal ischemia-reperfusion injury (RIRI), a complication of kidney transplantation [1], is commonly recognized as the material cause of acute kidney injury (AKI) with continuously growing mortality, morbidity and extended hospitalization [2]. RIRI is characterized by serious incidence of free radicals, main ischemia-induced cellular stress and intense inflammatory immune reactions which can result in extensive damage and necrosis of cells, as well as late interstitial fibrosis of the kidney allograft [3]. In general, the exhaustion of adenosine triphosphate in cells and tissues in the ischemic period is the origin of IRI, and then the oxidative damage occurs in the reperfusion period, followed by the elevation of biomarker protein levels [4]. The hematologic and biochemical tests are the conventional diagnostic methods for IRI [5]. However, efficient therapeutic method that can successfully treat IRI is still absent mainly due to the difficulty of mitigating tubulointerstitial fibrosis, inflammation, tubular and vascular injury, and intracellular events relate to RIRI [6]. With improved technologies for genetic study, the involvement of several microRNAs (miRs) as regulator and prognostic markers for RIRI has been discovered [7], but the specific mechanism remains unclear.