The acid-sensitive potassium channel TASK-1 in rat cardiac muscle

OBJECTIVE: The outward current flowing through the two-pore domain acid-sensitive potassium channel TASK-1 (I(TASK)) and its inhibition via alpha1-adrenergic receptors was studied in rat ventricular cardiomyocytes. METHODS: Quantitative RT-PCR experiments were carried out with mRNA from rat heart. Patch-clamp recordings were performed in isolated rat cardiomyocytes. TASK-1 and other K+ channels were expressed in Xenopus oocytes to study the pharmacological properties of a new TASK-1 channel blocker, A293. RESULTS: TASK-1 channels were found to be strongly expressed in rat heart. Analysis of the sensitivity of various K+ channels to A293 in Xenopus oocytes showed that at low concentrations A293 was a selective blocker of TASK-1 channels. I(TASK) in rat cardiomyocytes was dissected by application of A293 and by extracellular acidification to pH 6.0; it had an amplitude of approximately 0.30 pA/pF at +30 mV. Application of 200 nM A293 increased action potential duration (APD(50)) by 31+/-3% at a stimulation rate of 4 Hz. The plausibility of the effects of A293 on APD50 was checked with a mathematical action potential model. Application of the alpha1-adrenergic agonist methoxamine inhibited I(TASK) in Xenopus oocytes co-injected with cRNA for TASK-1 and alpha1A-receptors. In cardiomyocytes, methoxamine inhibited an outward current with characteristics similar to I(TASK). This effect was abolished in the presence of the alpha1A-antagonist 5-methyl-urapidil. CONCLUSIONS: Our results suggest that in rat cardiomyocytes I(TASK) makes a substantial contribution to the outward current flowing in the plateau range of potentials and that this current component can be inhibited via alpha1A-adrenergic receptors.     

长链非编码 RNA变异性浆细胞瘤异位 1通过调控微小 RNA-214-3p/人凋亡抑制蛋白 X轴影响皮肤黑色素瘤细胞的顺铂耐药性

目的探讨长链非编码 RNA(lncRNA)变异性浆细胞瘤异位 1(PVT1)调控微小 RNA(miR)-214-3p/人凋亡抑制蛋白 X(XIAP)对皮肤黑色素瘤( CMM)细胞的顺铂( DDP)耐药性的影响。方法该研究起止时间为 2020年 3—9月。体外培养人皮肤黑色素瘤 SK-MEL-1/DDP细胞,将细胞分为空白对照组( NG组,不做处理)、阴性转染组( NC组,转染 PVT1-inhibitor阴性对照)、抑制 PVT1表达组( PVT1-inhibitor组,转染 PVT1-inhibitor)、共转染组( PVT1-inhibitor-miR-214-3p-inhibitor组,转染 PVT1inhibitor同时转染 miR-214-3p-inhibitor)。采用实时荧光定量逆转录聚合酶链反应( qRT-PCR)检测 SK-MEL-1/DDP细胞 PVT1、 miR-214-3p水平; MTT法检测四组 SK-MEL-1/DDP细胞增殖能力及对 DDP的耐药性;流式细胞仪检测四组 SK-MEL-1/DDP细胞凋亡率;蛋白质印迹法( Western blotting)检测四组 SK-MEL-1/DDP细胞 XIAP、细胞增殖相关核抗原 Ki-67、凋亡相关蛋白 B细胞淋巴瘤 -2(Bcl-2)、 Bcl-2相关 X蛋白( Bax)表达水平。应用 TargetScan数据库预测 PVT1与 miR-214-3p的靶向关系,双荧光素酶报告基因实验验证。结果与 NG组、 NC组比较, PVT1-inhibitor组 SK-MEL-1/DDP细胞增殖抑制率［( 22.87±3.43)%比( 0.00± 0.00)%、(0.08±0.01)%］、凋亡率［( 40.05±6.06)%比( 15.69±2.35)%、(17.01±2.55)%］、 miR-214-3p及 Bax表达均显著升高( P< 0.05)PVT1、药物半数抑制浓度( IC50)值［( 15.13±0.45)μg/L比( 45.03±1.35)μg/L、(47.81±1.33)μg/L］、 Ki-67、Bcl-2蛋白、 XIAP mRNA及,其蛋白表达水平均显著降低( P<0.05);与 PVT1-inhibitor组比较, PVT1-inhibitor+miR-214-3p-inhibitor组 SK-MEL-1/ DDP细胞增殖抑制率［(15.12±2.27)%比( 22.87±3.43)%］、凋亡率［(27.88±4.19)%比( 40.05±6.06)%］、 miR-214-3p及 Bax表达均显著降低( P<0.05)IC50［(23.98±0.72)μg/L比(15.13±0.45)μg/L］Ki-67、Bcl-2蛋白、 XIAP mRNA及蛋白表达水平均显著升高(P<0.05)。TargetScan,数据值库预测显示 miR-214-3p是 PVT1的潜在靶、基因,双荧光素酶报告基因实验证实二者存在靶向关系。     

Clinical significance of episcleral venous fluid wave in gonioscopy-assisted transluminal trabeculotomy

AIM: To evaluate the clinical significance of checking episcleral venous fluid wave (EVFW) during gonioscopy-assisted transluminal trabeculotomy (GATT) in patients with open angle glaucoma (OAG). METHODS: This retrospective case series study comprised 30 patients (45 eyes) with OAG underwent GATT. The location and extent of EVFW were examined and graded after intraoperative compression flushing of the anterior chamber angle during the operation. Patients were followed up for 1y. A complete success for surgery is defined as a postoperative intraocular pressure (IOP) <18 mm Hg without any anti-glaucoma medication. IOP<18 mm Hg with less than two anti-glaucoma medications is defined as qualified success, while the control of IOP requiring three anti-glaucoma medications is considered as unsuccess. RESULTS: The mean IOP was 35.38±7.16 mm Hg before surgery and 15.52±4.22 mm Hg 1y after surgery (P<0.01). The average number of anti-glaucoma medication was 2.8±1.2 (2-4) preoperation and 0.6±1.3 (0-3) 1y postoperation (P<0.01). The success rate of the operation was 93.33%. Complete success rate was 66.67%, qualified success rate was 26.67%, and 6.66% of unsuccessful cases required reoperation. EVFW of all cases was grade 2-4, and the percentages of grade 2, 3 and 4 were 33.33%, 40.0% and 26.67%, respectively. The distribution and percentage of EVFW were inferior (36%), nasal (28%), superior (20%), and temporal (16%). The EVFW grade of complete success patients was 3.4±0.6 (3-4), and that of qualified success patients was 2.6±1.0 (2-4). The larger the range of EVFW, the lower the IOP, and the better the IOP reduction effect. CONCLUSION: During GATT surgery, pressurized irrigation of anterior chamber to check EVFW can reduce the outflow resistance of aqueous humor and increase the effect of postoperative IOP. The range of EVFW is negatively correlated with postoperative IOP. Therefore, EVFW may be a valuable prognostic indicator for the success of GATT surgery.     

紫外线对人皮肤成纤维细胞的影响

紫外线辐射可造成皮肤损伤,引起皮肤出现红斑、光老化等。紫外线作用于成纤维细胞,引起细胞因子分泌及基因表达的改变,不仅能造成真皮层的损伤,还可被用来治疗某些疾病,如局限性硬皮病。从紫外线对皮肤成纤维细胞的损伤、成纤维细胞对紫外线的防御反应及紫外线的应用等方面阐述了紫外线对成纤维细胞的影响。     

单眼盲对认知功能的影响及相关因素分析

目的分析单眼盲对认知功能的影响及相关因素。方法横断面研究。收集2018年1月至2020年6月就诊于首都医科大学附属北京同仁医院北京同仁眼科中心的单眼盲患者(单眼盲发生时年龄<16岁)。利用蒙特利尔认知评估(MoCA)量表测评患者认知功能(包括视空间与执行功能、命名能力、注意力等7个维度)。根据MoCA量表总分将患者分为认知功能正常组和认知功能障碍组。采用Spearman相关分析法对认知功能的影响因素进行单因素分析, 采用多元线性回归法进行认知功能障碍的独立危险因素分析。结果共纳入45例单眼盲患者, 其中男性25例, 女性20例;测评时年龄(27±10)岁。认知功能障碍发生率为60.0%(27/45), 7个纬度异常率从高到低依次为语言(95.6%, 43例)、延迟回忆(75.6%, 34例)、视空间与执行功能(60.0%, 27例)、抽象能力(44.4%, 20例)、注意力(35.6%, 16例)、命名能力(20.0%, 9例)和定向力(0%)。认知功能障碍组MoCA总分以及视空间与执行功能、命名能力、注意力、语言能力、抽象能力和延迟回忆6个纬度分值分别为(21.9±3.3)、(...     

Cellular mechanisms for methotrexate chemotherapy-induced bone growth defects

Methotrexate (MTX) is a commonly used anti-metabolite in childhood oncology and is known to cause bone growth arrest and osteoporosis; yet the underlying mechanisms for MTX-induced bone growth defects remain largely unclear. This study characterized damaging effects in young rats of acute chemotherapy with 5 once-daily doses of MTX (0.75 mg/kg) on the cellular activities in the growth plate in producing calcified cartilage and trabecular bone and on activities of osteoblastic cells in the metaphysis. MTX treatment significantly induced chondrocyte apoptosis. MTX also suppressed chondrocyte proliferation and reduced collagen-II mRNA expression and total thickness of the growth plate, with the damage being most obvious on day 9 after the first injection, and with the growth plate histological structure returning normal on day 14. In the adjacent metaphyseal bone, mirroring the decrease in the width of the growth plate, production of primary spongiosa bone was markedly reduced and bone volume of the secondary spongiosa was decreased. Furthermore, MTX treatment significantly induced osteocyte apoptosis in the primary spongiosa and reduced proliferation of osteoblasts and preosteoblasts particularly in the secondary spongiosa. These observations suggest that methotrexate chemotherapy may cause bone growth defects by arresting cellular activities in the growth plate in producing calcified cartilage and primary trabecular bone and by decreasing pools of metaphyseal osteoblastic cells. However, this short-term MTX treatment only caused transit suppressions on growth plate cartilage and trabecular bone, as most cellular and histological parameters had recovered by day 14 or 21.     

Platelet-rich plasma with keratinocytes and fibroblasts enhance healing of full-thickness wounds

Advances in tissue engineering led to the development of various tissue-engineered skin substitutes (TESS) for the treatment of skin injuries. The majority of the autologous TESS required lengthy and costly cell expansion process to fabricate. In this study, we determine the possibility of using a low density of human skin cells suspended in platelet-rich plasma (PRP)-enriched medium to promote the healing of full-thickness skin wounds. To achieve this, full-thickness wounds of size 1.767 cm² were created at the dorsum part of nude mice and treated with keratinocytes (2 × 10⁴ cells/cm²) and fibroblasts (3 × 10⁴ cells/cm²) suspended in 10% PRP-enriched medium. Wound examination was conducted weekly and the animals were euthanized after 2 weeks. Gross examination showed that re-epithelialization was fastest in the PRP+cells group at both day 7 and 14, followed by the PRP group and NT group receiving no treatment. Only the PRP+cells group achieved complete wound closure by 2 weeks. Epidermal layer was presence in the central region of the wound of the PRP+cells and PRP groups but absence in the NT group. Comparison between the PRP+cells and PRP groups showed that the PRP+cells-treated wound was more mature as indicated by the presence of thinner epidermis with single cell layer thick basal keratinocytes and less cellular dermis. In summary, the combination of low cell density and diluted PRP creates a synergistic effect which expedites the healing of full-thickness wounds. This combination has the potential to be developed as a rapid wound therapy via the direct application of freshly harvested skin cells in diluted PRP.