Macrophage-NLRP3 Inflammasome Activation Exacerbates Cardiac Dysfunction after Ischemic Stroke in a Mouse Model of Diabetes / 神经科学通报·英文版

Ischemic stroke is one of the leading causes of death worldwide. In the post-stroke stage, cardiac dysfunction is common and is known as the brain-heart interaction. Diabetes mellitus worsens the post-stroke outcome. Stroke-induced systemic inflammation is the major causative factor for the sequential complications, but the mechanism underlying the brain-heart interaction in diabetes has not been clarified. The NLRP3 (NLR pyrin domain-containing 3) inflammasome, an important component of the inflammation after stroke, is mainly activated in M1-polarized macrophages. In this study, we found that the cardiac dysfunction induced by ischemic stroke is more severe in a mouse model of type 2 diabetes. Meanwhile, M1-polarized macrophage infiltration and NLRP3 inflammasome activation increased in the cardiac ventricle after diabetic stroke. Importantly, the NLRP3 inflammasome inhibitor CY-09 restored cardiac function, indicating that the M1-polarized macrophage-NLRP3 inflammasome activation is a pathway underlying the brain-heart interaction after diabetic stroke.

Macrophage-NLRP3 Inflammasome Activation Exacerbates Cardiac Dysfunction after Ischemic Stroke in a Mouse Model of Diabetes / 神经科学通报·英文版

Ischemic stroke is one of the leading causes of death worldwide. In the post-stroke stage, cardiac dysfunction is common and is known as the brain-heart interaction. Diabetes mellitus worsens the post-stroke outcome. Stroke-induced systemic inflammation is the major causative factor for the sequential complications, but the mechanism underlying the brain-heart interaction in diabetes has not been clarified. The NLRP3 (NLR pyrin domain-containing 3) inflammasome, an important component of the inflammation after stroke, is mainly activated in M1-polarized macrophages. In this study, we found that the cardiac dysfunction induced by ischemic stroke is more severe in a mouse model of type 2 diabetes. Meanwhile, M1-polarized macrophage infiltration and NLRP3 inflammasome activation increased in the cardiac ventricle after diabetic stroke. Importantly, the NLRP3 inflammasome inhibitor CY-09 restored cardiac function, indicating that the M1-polarized macrophage-NLRP3 inflammasome activation is a pathway underlying the brain-heart interaction after diabetic stroke.

Transcription of protein arginine N-methyltransferase genes in mouse dorsal root ganglia following peripheral nerve injury / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes in the transcription of protein arginine methylation enzyme family genes in the dorsal root ganglia (DRG) following peripheral nerve injury in mice.</p><p><b>METHODS</b>C57BL6 mouse models of neuropathic pain induced by peripheral nerve injury were established by bilateral L4 spinal nerve ligation (SNL). At 7 days after SNL or sham operation, the DRG tissue was collected for transcriptional analysis of 9 protein arginine methylation enzyme genes (Prmt1?3, Carm1, and Prmt5?9) using RNA?Seq to identify the differentially expressed genes in the injured DRGs. We also established mouse models of lateral L4 SNL and models of chronic constriction injury (CCI) of the sciatic nerve and tested the paw withdrawal frequency (PWF) in response to mechanical stimulation and paw withdrawal latency (PWL) in response to thermal stimulation on 0, 3, 7 and 14 days after SNL or CCI; the expressions of the differentially expressed genes in the injured DRGs were verified in the two models using RT?qPCR.</p><p><b>RESULTS</b>Among the 9 protein arginine methylation enzyme family genes that were tissue?specifically expressed in the DRG, Prmt2 and Prmt3 showed the highest and Prmt6 showed the lowest basal expression. Compared with the sham?operated mice group, the mice receiving SNL exhibited upregulated Carm1 gene transcription (by 1.7 folds) but downregulated Prmt5, Prmt8 and Prmt9 transcription in the injured DRG (Prmt8 gene showed the most significant down?regulation by 16.3 folds). In mouse models of SNL and CCI, Carm1 gene expression increased progressively with time while Prmt8 transcription was obviously lowered on days 3, 7 and 14 after the injury; the transcription levels of Prmt1, Prmt5 and Prmt9 presented with no significant changes following the injuries. Both SNL and CCI induced mechanical allodynia and thermal hypersensitivities in the mice shown by increased PWF and decreased PWL on days 3, 7 and 14 after the injuries.</p><p><b>CONCLUSION</b>Periphery nerve injury induces Carm1 upregulation and Prmt8 downregulation in the injured DRG in mice, which sheds light on new targets for treatment of neuropathic pain.</p>

Investigating the dose-response curves of cisatracurium in the different gender epileptics / 临床麻醉学杂志

Objective To evaluate the gender differences in dose-response curve with cisatra-curium in epileptics.Methods Eighty ASA grade Ⅰ or Ⅱ epileptics were enrolled in this study.All patients were divided into male and the female groups and received the method of single dose injection under midazolam-fentanyl intravenous anesthesia.Each patient received intravenous bolus of 20,30, 40,50μg/kg of cisatracurium respectively.The neuromuscular block was measured by Neuromuscular Transmission Monitor and the responses were defined in terms of the percentages of maximum sup-pression in T1 of TOF of the adductor pollicis muscle.According to log-probit transformation of the data of dose and response,the dose-response curve of cisatracurium was established through linear re-gression.The onset time of cisatracurium was also observed.Results The ED50 ,ED75 ,ED90 ,ED95 values of cisatracurium in male epilepsy patients were 37.2±9.7,48.1±11.3,60.4±12.8,69.3± 14.0 μg/kg and that of female epilepsy patients were 36.6±4.3,47.5±7.7,60.5±14.0,70.1± 19.4 μg/kg.There was no significant difference between the two gender groups.No significant change in onset time was observed among 4 dose groups.Conclusion No gender differences are ob-served in dose-response curve of cisatracurium in epileptics.

Relationship between spinal function and the severity of spinal cord injury by needle puncture / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the changes in spinal cord pathophysiology, motor function and electrophysiology after spinal cord injuries induced by punctures with different needles, and explore a new means for studying spinal neurotoxicity of local anesthetics.</p><p><b>METHODS</b>A total of 144 SD rats were randomly allocated into the sham-operated group (n=36) and 3 spinal cord injury groups (n=36) with the L4-5 segment of the dura mater of the spinal cord punctured using 29G, 25G, and 21G needles. The BBB scores before surgery were recorded, and at 8 h, 24 h, 72 h, 1 week, and 2 weeks after the surgery, the motor evoked potential (MEP), spinal cord pathology and the BBB scores were examined.</p><p><b>RESULTS</b>In the control group, the rats showed normal BBB score, spinal function and microstructure. Spinal cord puncture with 29G needle did not cause obvious pathologies of the spinal cord, whereas puncture with 21G needle resulted in marked changes in the motor function, electrophysiology and histology of the spinal cord, which showed significant improvements at 2 weeks postoperatively.</p><p><b>CONCLUSION</b>Puncture with a 29G needle causes less injuries and minimal functional changes of the spinal cord, which can serve as a new means for studying spinal neurotoxicity of local anesthetics.</p>

Effect of ropivacaine-induced toxicity on learning and memory abilities and synaptophysin expression in immature mice / 中华神经医学杂志

Objective To study the effect of ropivacaine-induced toxicity on learning and memory abilities and synaptophysin expression of the hippocampus in immature mice. Methods Sixty 21-d-old SD mice were randomly divided into ropivacaine inducement group (R,n=30) and sodium chloride treatment group (N,n=30).Mice in each group were subdivided into 4 subgroups according to the different injection times (24 h,and 3,7 and 60 d after convulsion or injection,n=5); the protein expression of synaptophysin in the hippocampus at each time point were detected by Western blotting.The left 10 mice in each group were performed Mirror water maze test to explore the latency in finding the platform. Results The latency in finding the platform in mice of group R was gradually shortened as time being prolonged,and significant difference was noted between each 2 time points (P＜0.05); while no significant difference was noted between each 2 time points in mice of group N (P＞0.05).The latency in finding the platform in mice of group R was obviously longer as compared with that in group N at 24 h and 3 d time point (P＜0.05),but there were no significant differences at other time points (P＞0.05).The synaptophysin expression in the hippocampus of mice in group R was significantly lower as compared with that in group N at 24 h time point (P＜0.05). Conclusion The effect of single ropivacaine toxicity on learning and memory impairment of immature mice is transitional,which might be correlated to the synaptophysin expression in the hippocampus.

Identification and expression of shRNA vectors targeting human AMPKα2 / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct pGPU6/GFP/Neo-shRNA expression vector targeting human AMPKα2 gene and evaluate its silencing effect in SH-SY5Y cell line.</p><p><b>METHODS</b>The oligonucleotides designed by Ambion online CAD software targeting AMPKα2 were cloned into the pGPU6/GFP/Neo vector. After confirmation by DNA sequencing and enzyme digestion analysis, the recombinant vectors were transfected into the SH-SY5Y cell line via lipofectamine and the positive clones were selected using G418. The expression levels of AMPKα2 mRNA and protein in the transfected cells were detected by RT-PCR and Western blotting, respectively.</p><p><b>RESULTS</b>Four shRNA vectors were successfully constructed as confirmed by DNA sequencing and the enzyme digestion analysis. Among the 4 recombinant vectors, pGPU6/GFP/Neo-shRNA AMPKα2(3) showed the strongest gene silencing effect and down-regulated the protein expression of AMPKα2 by 63% in the transfected cells.</p><p><b>CONCLUSION</b>Transfection with pGPU6/GFP/Neo-shRNA AMPKα2(3) results in effective inhibition of AMPKα2 gene expression in SH-SY5Y cells, which provide a means for studying AMPK-mediated cell injury.</p>

Accuracy of perioperative cardiac preload monitoring by global end-diastolic volume and intrathoracic blood volume in orthotopic liver transplantation / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the clinical value of global end-diastolic volume (GEDV) and intrathoracic blood volume (ITBV) in perioperative monitoring of the cardiac preload in patients undergoing orthotopic liver transplantations (OLT).</p><p><b>METHODS</b>Eight ASA III or IV patients aged 42-50 years undergoing OLT without venovenous bypass under general anesthesia were enrolled in this study. Before the induction, a thermodilution femoral artery catheter was inserted into the femoral artery under local anesthesia and connected to a PiCCOplus system to monitor ITBV and GEDV. A CCO catheter was inserted into the right internal jugular vein to monitor the pulmonary artery obstruction pressure (PAOP), central venous press (CVP) and stroke volume (SVPAC). Anesthesia was induced with a combination of midazolam (0.1 mg/kg), propofol (1 mg/kg) and fentanyl (3 microg/kg). Pipecuronium (0.1 mg/kg) was given to facilitate naso-endotracheal intubation. Before anesthesia (T0) and at 10 min before the anhepatic phase (T1), 10 min after anhepatic phase (T2), 10 min after neohepatic phase (T3) and at the end of surgery (T4), all the TPTD and CCO parameters were measured by injecting 10 ml cold saline solution (below 8 degrees celsius;) via the distal port of the central venous catheter.</p><p><b>RESULTS</b>ITBV and GEDV at T2 were significantly lower than those at T0, T1, T3 and T4 (P<0.05). SVPAC at T2 was dramatically decreased compared with that at T0 and T1 (P<0.05). The changes in the pressure preload parameters of the pulmonary artery catheter (PAOP and CVP) did not correlate to the changes in SVPAC, whereas the changes in the volume preload parameters (ITBV and GEDV) of the TPTD was significantly correlated to the changes in SVPAC (P<0.01). PAOP and CVP did not correlate to the changes in ITBV and GEDV.</p><p><b>CONCLUSION</b>ITBV and GEDV are more reliable than PAOP and CVP in perioperative monitoring of the cardiac preload in patients undergoing OLT.</p>

Roles of phosphorylated extracellular signal-regulated kinase in rats with incisional hyperalgesia / 中华神经医学杂志

Objective To investigate the changes of phosphorylated extracellular signal-regulated kinase (p-ERK) expression in the immunoreactive cells of the spinal dorsal hom after plantar incision,and explore the effects of intrathecal administration of MEK inhibitor U0126 on physiological pain threshold in rat models with incisional pain.Methods Thirty-two male SD rats were equally randomized into control group (C group),incisional pain group (I group),intrathecal U0126 group (Ugroup) and intrathecal DMSO group (D group).Twenty-μL physiological saline was injected into the rats of the C group and I group,respectively.Ten-μL DMSO and U0126 were injected into the rats in the U group and D group,respectively.Rat models with incisionai pain were induced in the other 3 groups except the C group.Mechanical hyperalgesia were evaluated by paw-pressure before and 2,24 h and 2 d after the inducement.Another 24 rats were treated as the above method and equally divided into 4 groups; the numbers of p-ERK immunoreactive cells in the dorsal horn were quantified to determine the ERK activation 2 and 24 after the model inducement.Results The paw-pressure threshold in I group and D group 2 and 24 h,and 2 d after the incision,and that in U group 2 and 24 h after the incision were significantly decreased as compared with that in C group (P<0.05); that between I group and D group showed no significant difference (P>0.05); that in the U group was obviously higher than that in the I group and D group at the same time points (P<0.05).Significantly increased numbers of p-ERK immunoreactive cells in the I group and D group were observed as compared with those in the C group (P<0.05); those in the U group was obviously decreased as compared with those in the I group and D group at the same time points (P<0.05).Conclusion Plantar incision-induced mechanical hyperalgesia can be prevented by intrathecal injection of U0126 through decreasing the expression of p-ERK positive cells,indicating that ERK pathway in the spinal dorsal horn involves in the incision-induced mechanical hyperalgesia in rats.

Effect of intermittent intrathecal administration of ropivacaine and bupivacaine on rat hindlimb sensory and motor functions / 中华神经医学杂志

Objective To investigate the changes in the hindlimb sensory and motor functions and in the spinal dorsal root ganglion cells of rats following intrathecal administration of different concentrations of ropivacaine and bupivacaine. Methods Thirty SD rats weighing 200-250 g were anesthetized with intraperitoneal injection of 300-350 mg/kg 10% chloral hydrate. A polyurethane microcatheter was inserted into the lumbar subarachnoid space at the L3-4 level. The rats were randomized into 5 groups (n=6) to receive 40 μL artificial cerebrospinal fluid (CSF), 0.75%, 1%, and 2% lopivacaine or 2% bupivacaine administered intrathecally for 3 times at a 1.5-h interval. Spontaneous locomotion in an open field, foot splay in hindlimb landing, sensation of pain and heat in the hindlimbs were assessed one day before and daily after the first intrathecal administration. Results The rats receiving artificial CSF or 0.75% or 1% ropivacaine exhibited basically normal sensation of pain and heat, hindlimb locomotor function, and histology of the spinal cord and the dorsal root ganglion. The rats receiving 2% ropivacaine developed temporary mild sensory abnormalities, and those having 2% bupivacaine showed temporary muscle weakness and irreversible sensory abnormalities. Light microscopy revealed mild pathological changes in the neurons in the posterior white matter and nerve root in rots receiving 2% ropivacaine, and the rats receiving 2% bupivacaine showed obvious neuronal damage with vacuolization and degeneration of the neurons. Conclusion Intermittent intrathecal administration of ropivacaine at the concentration below 2% does not result in permanent spinal nerve injuries, but 2% ropivacaine or bupivacaine may cause neurotoxicity in the hindlimbs of rats, and the latter is associated with even greater damages.

Gender differences in rocuronium-induced neuromuscular blockade in patients undergoing abdominal surgery / 中华麻醉学杂志

Objective To evaluate the gender differences in neuromuscular blockade induced with rocuronium in patients undergoing abdominal surgery. Methods Twenty-four ASA Ⅰ or Ⅱ patients aged 20-59 yrs undergoing abdominal surgery under general anesthesia were enrolled in this study. Their body mass index (BMI) ranged between 18.5-25 kg?m-2. Patients with neuromuscular disease were excluded and no patient was taking any drug that might influence the effect of muscle relaxant. The patients were divided into male group ( n = 12) and female group (n = 12). The neuromuscular function was monitored and recorded using accelerography (DK-5210, Biometer, Denmark). The response of adductor pollicis muscle to train-of-four (TOF) stimulation of ulnar nerve were recorded. Body temperature was maintained at 36.0-36.9℃ and room temperature at 24-26℃ during surgery. The premedication included intramuscular atropine 0.01 mg?kg-1 and oral diazepam 10 mg. Anesthesia was induced with fentanyl 2-4 ?g?kg-1, propofol 2-3 mg?kg-1 and rocuronium 0.6 mg?kg-1. The patients were intubated and mechanically ventilated (VT = 7-10 ml RR = 12-14 bpm). PET CO2 was maintained between 35-45 mm Hg. Anesthesia was maintained with propofol by TCI (effect-site concentration was set at 3-4 ?g?ml-1) and intermittent i.v. boluses of fentanyl. Rocuronium (1 mg?ml-1) was infused and T1 was maintained at 5%-10% of the control height. At the end of surgery rocuronium infusion was terminated and neostigmine 0.05 mg?kg-1 was given i.v. .Results There were significant differences in body weight and height between male and female groups ( P