激动髓样细胞-2触发受体减轻围术期神经认知障碍

【摘要】 目的 研究髓样细胞 2触发受体（TREM2）是否参与成年小鼠手术诱发的围术期神经认知障碍（PND）。方法 将20只雄性野生型C57BL/6小鼠随机分为对照组和手术组各10只，在手术前24小时对小鼠进行恐惧条件训练，恐惧条件测试（FCT）分别在术后1、3和7天进行,并采用旷场实验评估小鼠的运动能力。在最后一次行为评估后，将动物处死进行Western blot检测TREM2的表达。将40只小鼠随机分为对照组、手术组、Hsp60+手术组和TREM2 siRNA+HSP60+手术组，每组各10只。手术前30分钟将TREM2 siRNA立体定向注射入侧脑室。选择性TREM2受体激动剂HSP60，在麻醉苏醒后立即腹腔注射5μg/小鼠，按前述方法每24小时注射一次，连续7天，在手术前24小时对小鼠进行恐惧条件训练，FCT分别分别在术后1、3和7天进行,并采用旷场实验评估小鼠的运动能力。在最后一次行为评估后，一半小鼠（n=5）用于Western blot和ELISA分析，另一半（n=5）用于免疫荧光检测。结果 在异氟烷麻醉下对成年C57BL/6小鼠行胫骨骨折髓内固定术，发现该手术不会损害小鼠的运动能力，但会恶化学习和记忆功能，并降低TREM2表达。通过使用选择性TREM2激动剂HSP60，发现TREM2在小鼠脑海马组织中的表达明显增加，从而改善了学习和记忆，并减轻了小鼠的神经炎症反应。TREM2 siRNA消除了HSP60诱导的TREM2表达的增加，并逆转了HSP60诱导的小鼠学习和记忆功能以及小鼠脑神经炎症水平的改善。结论 TREM2的上调可能与减轻神经炎症和改善学习记忆功能有关，并减少PND的发生。     

构建靶向血管内皮生长因子受体2可调控活性的嵌合抗原受体T细胞及其体外功能验证

目的构建靶向血管内皮生长因子受体2(VEGFR2)可调控活性的小分子门控嵌合抗原受体T(smgCAR-T)细胞系统并在体外验证其抗肿瘤和可调节活性。方法采用基因全长合成和磷酸钙转染法构建smgCAR-T及其阳性(CAR+-T)和阴性(CAR--T)对照细胞。同时构建表达VEGFR2的小鼠结直肠癌细胞(MCA38VEGFR2+)。验证并筛选构建成功的细胞后再体外验证CAR-T细胞靶向结合能力。在不同的效靶比下检测白细胞介素-2和肿瘤坏死因子-γ的浓度来评估CAR-T细胞的体外分泌功能,用乳酸脱氢酶浓度评估CAR-T细胞的体外抗肿瘤活性。组间的比较采用t检验或单因素方差分析。结果基因测序和流式细胞术证实CAR-T细胞和靶细胞构建成功。与对照组比较,CAR+-T细胞+MCA38VEGFR2+组具有最强的靶细胞杀伤能力。在smgCAR-T细胞+MCA38VEGFR2+组中,随着C16-(S)-3-甲基吲哚雷帕霉素(Rapalog)滴度升高靶细胞杀伤率逐渐升高;当Rapalog为40 nmol/L时杀伤率达到最大值,为(66.25±13.20)%。分别向smgCAR-T细胞+MCA38VEGFR2+细胞组(A和B组)加入40 nmol/L的Rapalog后,在24 h时可观察到两组杀伤率出现同步升高[(44.25±6.24)%比(49.25±5.56)%,t=1.197,P>0.05],差异无统计学意义。在置换培养基后,再次添加了Rapalog的A组中观察到靶细胞杀伤率升高明显;而未再次添加Rapalog的B组中靶细胞杀伤率升高缓慢;此时,A和B组杀伤率差异有统计学意义[(89.00±3.16)%比(56.50±6.61)%,t=8.873,P<0.01]。结论构建的smgCAR-T细胞在体外展现出一定的抗肿瘤活性,且其活性受小分子化合物Rapalog的可逆调控。     

Cholinergic hyperactivity in patients with myasthenia gravis with MuSK antibodies: A neurophysiological study

ObjectivePatients with myasthenia gravis associated with muscle-specific tyrosine kinase antibodies (MuSK-MG) often manifest signs of cholinergic hyperactivity with standard doses of acetylcholinesterase inhibitors (AChE-Is). Aim of the study was to investigate whether repetitive compound muscle action potential (R-CMAP), the neurophysiological correlate of cholinergic hyperactivity, was present in MuSK-MG irrespective of AChE-I treatment.MethodsPatients with confirmed diagnosis of MuSK-MG were consecutively enrolled during follow-up visits, from January 2019 to April 2020. All these subjects underwent the same neurophysiological protocol, including motor nerve conduction studies and repetitive nerve stimulation. In patients taking pyridostigmine, neurophysiological testing was performed at least 12 hours after the last dose. For comparison, the presence of R-CMAP was investigated in 20 consecutive acetylcholine receptor antibody positive myasthenia gravis (AChR-MG) patients.ResultsWe enrolled 25 MuSK-MG patients (20 females), aged 16–79 years at the study time, with disease duration ranging 0.6–48.8 years (median: 17.7 years). R-CMAP was detected in 12/25 (48%) MuSK-MG cases and in none of the AChR-MG controls (p = 0.0003). In the MuSK-MG population, a history of muscle cramps and fasciculations, during low-dose pyridostigmine therapy, was significantly more frequent in R-CMAP positive than in R-CMAP negative patients (100% vs 31%, p = 0.001). At the time of the study, the proportion of patients still symptomatic for MG was higher among R-CMAP positive cases (92% vs 23%, p = 0.0005).ConclusionsCholinergic hyperactivity is a relatively common finding in MuSK-MG patients, independent of AChE-I treatment, and may constitute an intrinsic feature of the disease.SignificanceR-CMAP detection can represent a useful diagnostic clue for MuSK-MG and predicts poor tolerance to AChE-Is.     

Impulse control disorders are associated with lower ventral striatum dopamine D3 receptor availability in Parkinson's disease: A [11C]-PHNO PET study

IntroductionReduced postsynaptic D3 dopaminergic receptor availability has been reported in the ventral striatum of pathological gamblers without Parkinson's disease (PD) and in patients with PD and impulse control disorders (ICD). However, a direct relationship between ventral striatum D3 dopaminergic receptors and the severity of ICD in PD patients has not yet been proven using a validated tool for ICD in PD, such as the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's disease-Rating Scale (QUIP-RS). In this pilot study, we investigated the relationship between ventral striatum D3 dopamine receptor availability and severity of impulse control disorder (ICD) in Parkinson's disease (PD).MethodsTwelve patients were assessed with PET and the high affinity dopamine D3 receptor radioligand [¹¹C]-PHNO. Severity of ICD was assessed with the QUIP-RS.ResultsWe found that lower ventral striatum D3 receptor availability measured with [¹¹C]-PHNO PET was associated with greater severity of ICD, as measured by the QUIP-RS score (rho = −0.625, p = 0.03).ConclusionThese findings suggest that the occurrence and severity of ICD in Parkinson's disease may be linked to reductions in ventral striatum dopamine D3 receptor availability. Further studies in larger cohort of patients need to be performed in order to confirm our findings and clarify whether lower ventral striatum D3 receptor may reflect a pharmacological downregulation to higher dopamine release in ventral striatum of patients with ICD or a patients' predisposition to ICD.     

Outcome of patients hospitalized for COVID‐19 and exposure to angiotensin‐converting enzyme inhibitors and angiotensin‐receptor blockers in France: results of the ACE‐CoV study

Data are lacking on the impact of ACEI/ARB exposure on unfavorable outcome in the population of patients hospitalized for COVID‐19 with hypertension/cardiovascular disease, particularly in Europe. The ACE‐CoV study was designed to assess this question. The study was conducted in the Covid‐Clinic‐Toul cohort, which contains data about all patients hospitalized at Toulouse University hospital, France with a SARS‐CoV‐2 infection since March, 2020. We selected the patients with a history of cardiovascular disease (heart failure or coronary disease) and/or arterial hypertension. We conducted a subgroup analysis in patients with arterial hypertension. ACEI/ARB exposures at admission were assessed. The outcome was composite: admission to intensive care unit, need of mechanical ventilation or death during the 14 days after admission to hospital. We used logistic regression models with propensity scores (PS) weighted by overlap weighting (OW) and inverse probability of treatment weighting (IPTW). Between March 2020 and April 20, 2020, the Covid‐Clinic‐Toul included 263 patients. Among them, 111 were included in the ACE‐CoV study population. In OW‐PS‐adjusted analyses, the association of exposure to ACEIs or ARBs with outcome occurrence was OR: 1.56 (95% CI: 0.73–3.33). It was 0.99 (95% CI: 0.68–1.45) for ACEIs and 1.64 (95% CI: 0.77–3.50) for ARBs. Analyses with weighting by the IPTW‐PS method gave similar results. Results were similar when considering the subgroup of patients with arterial hypertension. The ACE‐CoV study found no association between exposure to ACEIs or ARBs and unfavorable outcome in hospitalized patients for COVID‐19 with a history of cardiovascular disease/arterial hypertension.     

Gene annotation of nuclear receptor superfamily genes in the kissing bug Rhodnius prolixus and the effects of 20-hydroxyecdysone on lipid metabolism

The hormone 20-hydroxyecdysone is fundamental for regulating moulting and metamorphosis in immature insects, and it plays a role in physiological regulation in adult insects. This hormone acts by binding and activating a receptor, the ecdysone receptor, which is part of the nuclear receptor gene superfamily. Here, we analyse the genome of the kissing bug Rhodnius prolixus to annotate the nuclear receptor superfamily genes. The R. prolixus genome displays a possible duplication of the HNF4 gene. All the analysed insect organs express most nuclear receptor genes as shown by RT-PCR. The quantitative PCR analysis showed that the RpEcR and RpUSP genes are highly expressed in the testis, while the RpHNF4-1 and RpHNF4-2 genes are more active in the fat body and ovaries and in the anterior midgut, respectively. Feeding does not induce detectable changes in the expression of these genes in the fat body. However, the expression of the RpHNF4-2 gene is always higher than that of RpHNF4-1. Treating adult females with 20-hydroxyecdysone increased the amount of triacylglycerol stored in the fat bodies by increasing their lipogenic capacity. These results indicate that 20-hydroxyecdysone acts on the lipid metabolism of adult insects, although the underlying mechanism is not clear.     

A modality-specific somatosensory evoked potential test protocol for clinical evaluation: A feasibility study

ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.