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Purpose Anesthetic reagents, such as bupivacaine (Bv), induce significant neurotoxicity in dorsal root ganglion neurons (DRGNs). In this study, we investigated the expression, function and cross-association of microRNA-137-3p (miR-137-3p) and lysine (K)-specific demethylase 1A (LSD1) in a murine model of Bv-induced neural injury in DRGNs. Methods Murine DRGNs were culture in vitro and treated with Bv. QPCR was used to evaluate miR-137-3p expression in Bv-injured DRGNs. MiR-137-3p was genetically downregulated to evaluate its rescuing effect on Bv-induced DRGN apoptosis and neurite retraction. The association of miR-137-3p on its downstream target, LSD1 coding gene KDM1A, was evaluated by dual-luciferase activity assay and qPCR. In miR-137-3p-downregulated DRGNs, KDM1A was inhibited to evaluate its involvement in miR-137-3p-mediated modulation on Bv-induced DRGN neurotoxicity. Furthermore, KDM1A expression in Bv-injured DRGN was evaluated by qPCR, and LSD1 was overexpressed in DRGN to evaluate its direct effect on Bv-induced neurotoxicity. Results MiR-137-3p was upregulated in Bv-injured DRGNs. MiR-137-3p downregulation rescued Bv-induced DRGN apoptosis and neurite retraction. LSD1 was demonstrated to be downstream to, and inversely modulated by miR-137-3p in DRGN. In Bv-injured DRGNs, LSD1 downregulation reversed miR-137-3p-downregualtion-induced neural protection. Furthermore, LSD1 upregulation directly rescued Bv-induced apoptosis and neurite retraction in DRGNs. Conclusions MiR-137-3p and its downstream target LSD1 are inversely associated to regulate anesthetics-induced neurotoxicity in DRGN. This signaling pathway may be a therapeutic candidate to reduce anesthetics-induced neurological damage in human patients.

Aims Dexmedetomidine (Dex) has been noted to have neuroprotective effect against cerebral ischemia-reperfusion (I/R) injury. However, the effect of Dex in diabetic hyperglycemia-exacerbated cerebral I/R injury and its underlying mechanism remain unclear. Main methods The infarct volume and brain edema were evaluated by 2,3,5-triphenyltetrazolium chloride staining and standard wet-dry method. Modified neurological severity score was utilized to assess the neurological deficits. The oxidative stress and inflammation were evaluated by detecting reactive oxygen species (ROS), malondialdehyde (MDA), tumor necrosis factor (TNF)-α and interleukin (IL)-1β. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay and cell count kit-8 were applied to measure cell apoptosis and viability. Key findings Dex treatment reduced infarct volume, decreased brain water content and improved neurological deficit in middle cerebral artery occlusion/reperfusion (MCAO/R) mice. Dex treatment reduced the levels of ROS, MDA, TNF-α and IL-1β in the entire middle cerebral artery territory of diabetic mice subjected to MCAO/R, as well as in primary culture of mouse hippocampal neurons stimulated with 50 mM glucose and oxygen glucose deprivation/reperfusion. Dex treatment inhibited neuronal apoptosis induced by diabetic hyperglycemia-exacerbated cerebral I/R injury. Dex upregulated nuclear factor of activated T-cells 5 (NFAT5) and Sirtuin 1 (SIRT1) expression, induced NF-E2-related factor 2 (Nrf2) translocation from cytoplasm to nucleus and inhibited the acetylation of Nrf2. However, these changes triggered by Dex treatment were abrogated by NFAT5 knockdown. Significance Dex protects against diabetic hyperglycemia-exacerbated cerebral I/R injury through attenuation of oxidative stress, inflammation and apoptosis. The underlying mechanism is at least the NFAT5/SIRT1/Nrf2 signaling pathway dependent.

International audience; The design, dynamics, and workspace of a hybrid-driven-based cable parallel manipulator (HDCPM) are presented. The HDCPM is able to perform high efficiency, heavy load, and high-performance motion due to the advantages of both the cable parallel manipulator and the hybrid-driven planar five-bar mechanism. The design is performed according to theories of mechanism structure synthesis for cable parallel manipulators.The dynamic formulation of the HDCPM is established on the basis of Newton- Euler method. The workspace of the manipulator is analyzed additionally. As an example, a completely restrained HDCPM with 3 degrees of freedomis studied in simulation in order to verify the validity of the proposed design, workspace, and dynamic analysis. The simulation results, compared with the theoretical analysis, and the case study previously performed show that the manipulator design is reasonable and the mathematical models are correct, which provides the theoretical basis for future physical prototype and control system design.