The transient receptor potential melastatin 2:a new therapeutical target for Parkinson's disease?

The transient receptor potential melastatin 2 is a calcium-permeable cation channel member of the TRP family. Also known as an oxidative stress-activated channel, the transient receptor potential melastatin 2 gating mechanism is dependent on reactive oxygen species. In pathological conditions, transient receptor potential melastatin 2 is overactivated, leading to a Ca~(2+) influx that alters cell homeostasis and promotes cell death. The role of transient receptor potential melastatin 2 in neurodegenerative diseases, including Alzheimer's disease and ischemia, has already been described and reviewed. However, data on transient receptor potential melastatin 2 involvement in Parkinson's disease pathology has emerged only in recent years and the issue lacks review studies that focus specifically on this topic. The present review aims to elucidate the role of the transient receptor potential melastatin 2 channel in Parkinson's disease by reviewing, summarizing, and discussing the in vitro, in vivo, and human studies published until August 2022. Here we describe fourteen studies that evaluated the transient receptor potential melastatin 2 channel in Parkinson's disease. The Parkinson's disease model used, transient receptor potential melastatin 2 antagonist and genetic approaches, and the main outcomes reported were discussed. The studies described transient receptor potential melastatin 2 activation and enhanced expression in different Parkinson's disease models. They also evidenced protective and restorative effects when using transient receptor potential melastatin 2 antagonists, knockout, or silencing. This review provides a literature overview and suggests where there is a need for more research. As a perspective point, this review shows evidence that supports transient receptor potential melastatin 2 as a pharmacological target for Parkinson's disease in the future.

Melastatin-related transient receptor potential 2 channel in Aβ_(42)-induced neuroinflammation: implications to Alzheimer's disease mechanism and development of therapeutics

Alzheimer’s disease （AD） is an age-related eurodegenerative disease that represents the most common cause of dementia among the elderly people. With the increasingly aging population, AD has presented an overwhelming healthcare challenge to modern society; the World Alzheimer Report 2015 has estimated that 46.8 million people worldwide lived with dementia in 2015 and this number will rise to 74.7 million in 2030 and that the total cost of dementia was 818 billion in US$ in 2015 and will reach two trillion in 2030. Post-mortem studies have identified two histopathological hallmarks in the brains of AD patients; extracellular senile plaque with elevated deposition of amyloid β （Aβ） peptides, and intracellular neurofibrillary tangle composed of hyper-phosphorylated microtubule-associated protein tau.Etiologically, progressive neuronal loss within the cerebral cortex and hippocampus regions of the brain leads to irreversible decline in, and eventually complete loss of, memory and other cognitive functions that afflict AD patients. The widely-accepted amyloid cascade hypothesis for AD pathogenesis holds that accumulation and aggregation of neurotoxic Aβ peptides, due to imbalance of their generation and clearance as a result of changes in genetic makeup, aging and/or exposure to environmental risk factors, is a major and early trigger of AD. This hypothesis has continuously gained support by preclinical and clinical studies （Selkoe and Hardy, 2016）. However, the intensive and costly drug discovery efforts over the past decades based on such a hypothesis have proved extremely frustrating in developing effective therapeutics to treat or slow down the progress of AD, highlighting the need for more research to improve our understanding towards the cellular and molecular mechanisms by which Aβ peptides bring about neurotoxicity and cognitive dysfunction.

Distribution profiles of transient receptor potential melastatin-related and vanilloid-related channels in prostatic tissue in rat

Aim： To investigate the expression and distribution of the members of the transient receptor potential （TRP） channel members of TRP melastatin （TRPM） and TRP vanilloid （TRPV） subfamilies in rat prostatic tissue. Methods： Prostate tissue was obtained from male Sprague-Dawley rats. Reverse transcription polymerase chain reaction （RT-PCR） and quantitative real-time polymerase chain reaction （PCR） were used to check the expression of all TRPM and TRPV channel members with specific primers. Immunohistochemistry staining for TRPM8 and TRPV1 were also performed in rat tissues. Results： TRPM2, TRPM3, TRPM4, TRPM6, TRPM7, TRPMS, TRPV2 and TRPV4 mRNA were detected in all rat prostatic tissues. Very weak signals for TRPM1, TRPVI and TRPV3 were also detected. The mRNA of TRPM5, TRPV5 and TRPV6 were not detected in all RT-PCR experiments. Quantitative real-time RT-PCR showed that TRPM2, TRPM3, TRPM4, TRPMS, TRPV2 and TRPV4 were the most abundantly expressed TRPM and TRPV subtypes, respectively. Fluorescence immunohistochemistry indicated that TRPM8 and TRPV 1 are highly expressed in both epithelial and smooth muscle cells. Conclusion： Our results demonstrate that mRNA or protein for TRPM1, TRPM2, TRPM3, TRPM4, TRPM6, TRPM7, TRPMS, TRPV1, TRPV2, TRPV3 and TRPV4 exist in rat prostatic tissue. The data presented here assists in elucidating the physiological function of TRPM and TRPV channels.

Blockade of transient receptor potential cation channel subfamily V member 1 promotes regeneration after sciatic nerve injury

The transient receptor potential cation channel subfamily V member 1（TRPV1） provides the sensation of pain（nociception）. However, it remains unknown whether TRPV1 is activated after peripheral nerve injury, or whether activation of TRPV1 affects neural regeneration. In the present study, we established rat models of unilateral sciatic nerve crush injury, with or without pretreatment with AMG517（300 mg/kg）, a TRPV1 antagonist, injected subcutaneously into the ipsilateral paw 60 minutes before injury. At 1 and 2 weeks after injury, we performed immunofluorescence staining of the sciatic nerve at the center of injury, at 0.3 cm proximal and distal to the injury site, and in the dorsal root ganglia. Our results showed that Wallerian degeneration occurred distal to the injury site, and neurite outgrowth and Schwann cell regeneration occurred proximal to the injury. The number of regenerating myelinated and unmyelinated nerve clusters was greater in the AMG517-pretreated rats than in the vehicle-treated group, most notably 2 weeks after injury. TRPV1 expression in the injured sciatic nerve and ipsilateral dorsal root ganglia was markedly greater than on the contralateral side. Pretreatment with AMG517 blocked this effect. These data indicate that TRPV1 is activated or overexpressed after sciatic nerve crush injury, and that blockade of TRPV1 may accelerate regeneration of the injured sciatic nerve.

2-aminoethoxydiphenyl borate or lanthanum potentiates transient receptor potential-like channels in rat CA1 hippocampal neurons

Expression of transient receptor potential （TRP） channels is widespread with transcripts distributed throughout the brain. All TRP channel subunits are activated following phospholipase C activation and form cation-selective ion channels. Previous studies examining the existence of TRP channels in hippocampal CA1 pyramidal neurons were based on cultured neurons. Therefore, their relevance for living tissue remains unclear. In the present study, patch-clamp recordings were conducted from CA1 pyramidal neurons in hippocampal slices from 7-day-old rats. Whole-cell currents were obtained from CA1 hippocampal neurons with potentiation effects of 2-aminoethoxydiphenyl borate and lanthanum, revealing that recorded experimental currents were characteristic TRP-like channel currents. Identification of rat hippocampal mRNA transcripts of TRPC4, TRPC5, TRPV1, TRPV2, and TRPV3 channels further verified the expression of characteristic TRP-like channels on rat CA1 hippocampal neurons.

Roles of transient receptor potential channel 6 in glucose-induced cardiomyocyte injury

BACKGROUND Diabetic cardiomyopathy(DCM) is a serious complication of end-stage diabetes that presents symptoms such as cardiac hypertrophy and heart failure. The transient receptor potential channel 6(TRPC6) protein is a very important selective calcium channel that is closely related to the development of various cardiomyopathies.AIM To explore whether TRPC6 affects cardiomyocyte apoptosis and proliferation inhibition in DCM.METHODS We compared cardiac function and myocardial pathological changes in wild-type mice and mice injected with streptozotocin(STZ), in addition to comparing the expression of TRPC6 and P-calmodulin-dependent protein kinase Ⅱ(P-CaMKⅡ) in them. At the same time, we treated H9C2 cardiomyocytes with high glucose and then evaluated the effects of addition of SAR, a TRPC6 inhibitor, and KN-93, a CaMKⅡ inhibitor, to such H9C2 cells in a high-glucose environment.RESULTS We found that STZ-treated mice had DCM, decreased cardiac function, necrotic cardiomyocytes, and limited proliferation. Western blot and immunofluorescence were used to detect the expression levels of various appropriate proteins in the myocardial tissue of mice and H9C2 cells. Compared to those in the control group, the expression levels of the apoptosis-related proteins cleaved caspase 3 and Bax were significantly higher in the experimental group, while the expression of the proliferation-related proteins proliferating cell nuclear antigen(PCNA) and CyclinD1 was significantly lower. In vivo and in vitro, the expression of TRPC6 and P-CaMKⅡ increased in a high-glucose environment. However, addition of inhibitors to H9C2 cells in a high-glucose environment resulted in alleviation of both apoptosis and proliferation inhibition.CONCLUSION The inhibition of apoptosis and proliferation of cardiomyocytes in a high-glucose environment may be closely related to activation of the TRPC6/P-CaMKⅡ pathway.

Distribution of transient receptor potential vanilloid-1 channels in gastrointestinal tract of patients with morbid obesity

BACKGROUND Transient receptor potential vanilloid-1(TRPV1),a nonselective cation channel,is activated by capsaicin,a pungent ingredient of hot pepper.Previous studies have suggested a link between obesity and capsaicin-associated pathways,and activation of TRPV1 may provide an alternative approach for obesity treatment.However,data on the TRPV1 distribution in human gastric mucosa are limited,and the degree of TRPV1 distribution in the gastric and duodenal mucosal cells of obese people in comparison with normal-weight individuals is unknown.AIM To clarify gastric and duodenal mucosal expression of TRPV1 in humans and compare TRPV1 expression in obese and healthy individuals.METHODS Forty-six patients with a body mass index(BMI)of>40 kg/m^(2) and 20 patients with a BMI between 18-25 kg/m^(2) were included.Simultaneous biopsies from the fundus,antrum,and duodenum tissues were obtained from subjects between the ages of 18 and 65 who underwent esophagogastroduodenoscopy.Age,sex,history of alcohol and cigarette consumption,and past medical history regarding chronic diseases and medications were accessed from patient charts and were analyzed accordingly.Evaluation with anti-TRPV1 antibody was performed separately according to cell types in the fundus,antrum,and duodenum tissues using an immunoreactivity score.Data were analyzed using SPSS 17.0.RESULTS TRPV1 expression was higher in the stomach than in the duodenum and was predominantly found in parietal and chief cells of the fundus and mucous and foveolar cells of the antrum.Unlike foveolar cells in the antrum,TRPV1 was relatively low in foveolar cells in the fundus(4.92±0.49 vs 0.48±0.16,P<0.01,Mann-Whitney U test).Additionally,the mucous cells in the duodenum also had low levels of TRPV1 compared to mucous cells in the antrum(1.33±0.31 vs 2.95±0.46,P<0.01,Mann-Whitney U test).TRPV1 expression levels of different cell types in the fundus,antrum,and duodenum tissues of the morbidly obese group were similar to those of the control group.Staining with TRPV1 in fundus chief cells and antrum and duodenum mucous cells was higher in patients aged≥45 years than in patients<45 years(3.03±0.42,4.37±0.76,2.28±0.55 vs 1.9±0.46,1.58±0.44,0.37±0.18,P=0.03,P<0.01,P<0.01,respectively,Mann-Whitney U test).The mean staining levels of TRPV1 in duodenal mucous cells in patients with diabetes and hypertension were higher than those in patients without diabetes and hypertension(diabetes:2.11±0.67 vs 1.02±0.34,P=0.04;hypertension:2.42±0.75 vs 1.02±0.33,P<0.01 Mann-Whitney U test).CONCLUSION The expression of TRPV1 is unchanged in the gastroduodenal mucosa of morbidly obese patients demonstrating that drugs targeting TRPV1 may be effective in these patients.

Transient Receptor Potential Melastatin 3 and Intracellular Calcium in Natural Killer Cells in Multiple Sclerosis

Background: Natural killer (NK) cell phenotypes have reported to be implicated in the pathomechanism of Multiple Sclerosis (MS). Several investigators have observed reduced peripheral numbers, reduced cytotoxic activity, and altered CD56Dim and CD56Bright NK cell phenotypes. This current project, for the first time, investigates the NK cell cytotoxicity, calcium mobilisation and transient receptor potential melastatin 3 (TRPM3) surface expression. Methods: NK cell cytotoxic activity and calcium signaling were examined in CD56Dim and CD56Bright NK cells before and after stimulation using Ionomycin, Pregnenolone sulphate, 2-Aminoethoxydiphenyl borate and Thapsigargin. Purified NK cells were labelled with antibodies to determine TRPM3, CD69 and CD107a surface expression using flow cytometry. Results: Twenty-two MS patients and 22 healthy controls were recruited for this project. Twelve of the 22 previously received Alemtuzumab (Lemtrada&reg;) and the remaining ten reported nil medication. We report TRPM3 was significantly increased in untreated MS patients compared with healthy controls and treated MS patients (p-value 0.034). There was a significant decrease in CD69 surface expression on CD56Dim NK cell phenotype for untreated MS patients (p-value 0.031) and treated MS patients (p-value 0.036). We report altered calcium mobilisation in CD56Bright NK cells and to a lesser extent CD56Dim NK cells between healthy controls, treated and untreated MS patients. Conclusion: This investigation suggests variations in TRPM3 expression and calcium mobilisation of NK cells may be implicated in the pathogenesis of MS. Further investigation is required to determine the mechanism by which alemtuzumab alters calcium signaling in NK cells.

瞬时感受器电位离子通道香草素受体亚家族Ⅳ在帕金森病细胞模型中介导PC12细胞炎症反应的机制

目的探讨瞬时感受器电位离子通道香草素受体亚家族Ⅳ(TRPV4)在帕金森病(PD)细胞模型中介导PC12细胞炎症反应的机制。方法2023年6―8月,用1-甲基-4-苯基吡啶离子(MPP^(+))建立PD细胞模型,用TRPV4特异性抑制剂HC067047抑制TRPV4。将培养的PC12细胞采用随机数字表法分为四组:对照组、HC067047组、MPP^(+)组、HC067047+MPP^(+)组。细胞毒性检测试剂盒(CCK-8)检测各组细胞的增殖活力。蛋白印迹法和酶联免疫吸附测定(ELISA)检测各组细胞TRPV4和炎症因子白细胞介素-18(IL-18)、白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)的水平变化。结果与对照组1.00±0.08相比,MPP^(+)组TRPV4的表达量2.14±0.20明显升高(P<0.001)。与对照组1.00±0.01相比,MPP^(+)组的PC12细胞活力0.65±0.08明显降低(P<0.01),而HC067047能明显回复MPP^(+)引起的细胞活力0.83±0.07降低(P<0.01)。与对照组相比,MPP^(+)组的IL-181.96±0.27和IL-61.92±0.18、IL-1β(874.61±108.09)ng/L和TNF-α(791.28±106.88)ng/L明显升高(P<0.001),HC067047能明显抑制MPP^(+)引起的IL-181.45±0.11和IL-61.58±0.22、IL-1β(626.28±84.53)ng/L和TNF-α(592.94±86.9)4 ng/L明显升高(P<0.01或P<0.05)。结论TRPV4参与了MPP^(+)诱导的PD细胞模型的炎症反应,抑制TRPV4有抗炎作用。

TRPM7和BTG2在宫颈癌组织中的表达及临床意义

目的探讨瞬时受体电位M7通道(TRPM7)和B细胞迁移基因2(BTG2)在宫颈癌组织中的表达及临床意义。方法选取2018年5月至2020年5月石家庄市妇幼保健院收治的110例宫颈癌患者作为研究对象,术中取其肿瘤组织及癌旁组织,根据随访情况分为预后良好组与预后不良组。采用免疫组化法检测癌旁组织和肿瘤组织中TRPM7、BTG2蛋白表达,分析TRPM7、BTG2蛋白表达水平与患者临床病理特征的关系,比较预后不良组与预后良好组肿瘤组织中TRPM7、BTG2蛋白表达,采用Cox回归分析宫颈癌患者预后的影响因素,采用Kaplan-Meier曲线分析TRPM7、BTG2水平与宫颈癌患者预后的关系。结果与癌旁组织比较,肿瘤组织中TRPM7蛋白表达水平升高,BTG2蛋白表达水平降低(P<0.05)。TRPM7、BTG2蛋白表达水平与肿瘤分化程度、淋巴结转移、恶性肿瘤国际临床病理(TNM)分期有关(P<0.05)。与预后良好组比较,预后不良组肿瘤组织中TRPM7蛋白表达水平升高,BTG2蛋白表达水平降低(P<0.05)。TRPM7、TNM分期(Ⅲ期)、肿瘤低分化程度、淋巴结转移是宫颈癌患者预后的危险因素(P<0.05),BTG2是宫颈癌患者预后的保护因素(P<0.05)。TRPM7高表达组3年生存率低于TRPM7低表达组(P<0.05);BTG2高表达组3年生存率高于BTG2低表达组(P<0.05)。结论宫颈癌患者肿瘤组织中TRPM7蛋白表达上调,BTG2蛋白表达下调,均与宫颈癌预后有关。

基于PiggyBac转座子优化稳定表达细胞系的新型瞬时受体电位M2通道抑制剂筛选

目的:使用PiggyBac(PB)转座系统建立稳定表达瞬时受体电位M2(TRPM2)通道的人胚胎肾细胞HEK293T,并进行TRPM2通道抑制剂筛选,为治疗脑缺血等疾病寻找潜在的药物。方法:根据PB转座原理,构建pPB-hTRPM2真核表达载体。将重组质粒和辅助质粒共同转染至HEK293T细胞中,利用系统携带的荧光与膜片钳鉴定TRPM2基因表达,通过Z'因子评估细胞模型是否适用于钙成像法的高通量筛选。利用钙成像法和膜片钳对11个先导化合物分子进行初步活性评价,测定化合物分子对TRPM2通道的抑制活性。利用氧糖剥夺/再灌注(OGD/R)损伤模型和细胞计数试剂盒8(CCK-8)方法验证筛选得到的化合物分子对损伤细胞的保护作用。利用流式细胞术检测细胞活性氧水平。利用小鼠短暂性大脑中动脉栓塞(tMCAO)模型评价化合物的神经保护作用。结果:成功构建pPB-hTRPM2真核表达载体,构建出可高效表达TRPM2基因的HEK293T细胞系,并同时表达增强型绿色荧光蛋白(EGFP)。在筛选获得的嘌呤霉素抗性细胞中,所有细胞荧光明亮可见,诱导后细胞表现出经典的TRPM2通道电流特征,TRPM2通道电流值与瞬时转染对照组差异无统计学意义(P>0.05)。该筛选系统进行钙成像实验的Z'因子为0.5416,表明其适用于高通量筛选。通过钙成像法结合膜片钳筛选出化合物6,其具有显著的TRPM2通道抑制作用,且1.0μmol/L的化合物6能够显著提高OGD/R后SH-SY5Y细胞的存活率(P<0.05),降低活性氧水平(P<0.05),0.3、1.0 mg/kg的化合物6能降低tMCAO小鼠脑梗死体积百分比(均P<0.05)。结论:利用PiggyBac基因编辑技术成功构建了TRPM2基因稳定表达细胞系,利用钙成像法和膜片钳在候选化合物中成功筛选出一个高亲和力的新的TRPM2通道抑制剂。该抑制剂可以通过降低细胞活性氧水平缓解OGD/R后细胞损伤,并对小鼠脑缺血再灌注损伤具有保护作用。

精神分裂症患者血清成纤维细胞生长因子2、瞬时受体电位通道1水平与精神症状的相关性

目的探讨成纤维细胞生长因子2(FGF2)、瞬时受体电位通道1(TRPC1)在精神分裂症患者中的表达及与精神症状的相关性。方法选取2019年7月至2022年6月医院收治的200例精神分裂症患者和进行健康体检的正常人群200例分别设为观察组和对照组。收集一般资料,采用酶联免疫吸附法检测血清中FGF2表达水平;采用WD-3000全自动血液分析仪和免疫比色法检测TRPC1水平;采用阳性与阴性症状量表(PANSS)评价精神症状;Pearson法分析FGF2、TRPC1与精神症状指标的相关性。利用受试者工作特征(ROC)曲线评价血清FGF2、TRPC1水平对精神分裂症的诊断价值。结果观察组患者血清中TRPC1表达水平均低于对照组,FGF2表达水平高于对照组(P<0.05);观察组患者总PANSS评分、阳性评分、阴性评分、一般症状评分均高于对照组(P<0.05);精神分裂症患者血清FGF2表达与总PANSS评分、阳性评分、阴性评分、一般症状评分均呈正相关,TRPC1表达与总PANSS评分、阳性评分、阴性评分、一般症状评分均呈负相关(P<0.05)。血清FGF2、TRPC1水平预测精神分裂症患者的ROC曲线下面积(AUC)分别为0.928、0.911,对应的敏感度分别为84.00%、89.50%,特异度分别为89.00%、86.50%;两者联合检测精神分裂症患者的AUC为0.969,敏感度和特异度分别为94.50%、90.00%。结论精神分裂症患者血清FGF2水平明显升高,TRPC1水平明显降低,血清FGF2、TRPC1水平与患者的精神症状密切相关。

Identification of TRPM7 channels in human intestinal interstitial cells of Cajal

AIM： To investigate the characteristics of slow electrical waves and the presence of transient receptor potential melastatin-type 7 （TRPM7） in the human gastrointestinal （GI） tract. METHODS： Conventional microelectrode techniques were used to record intracellular electrical responses from human GI smooth muscle tissue. Immunohistochemistry was used to identify TRPM7 channels in interstitial cells of Cajat （ICCs）. RESULTS： The human GI tract generated slow electrical waves and had ICCs which functioned as pacemak er cells. Flufenamic acid, a nonselective cation channel blocker, and 2-APB （2-aminoethoxydiphenyl borate） and La3＋, TRPM7 channel blockers, inhibited the slowwaves. Also, TRPM7 channels were expressed in ICCs in human tissue. CONCLUSION： These results suggest that the human GI tract generates slow waves and that TRPM7 channels expressed in the ICCs may be involved in the gen- eration of the slow waves.

Measuring Ca^(2+) influxes of TRPC1-dependent Ca^(2+) channels in HL-7702 cells with Non-invasive Micro-test Technique

AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a normal human liver cell line.METHODS： Net Ca^2＋ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPCl were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction.RESULTS： Ca^2＋ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells. They were enhanced by addition of 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 （a non-selective Ca^2＋ channel blocker）; 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2＋ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION： In HL-7702 cells, there is a type of TRPCl-dependent Ca^2＋ channel, which could be detected v/a NMT and inhibited by La^3＋.

黄芪提取物调节TRPM2表达的抗急性药物性肝损伤作用研究

目的 探讨黄芪提取物(AR)调节TRPM2表达的抗急性DILI作用机制。方法 雄性小鼠39只,随机分为对照组(n=7),对乙酰氨基酚(APAP)模型组,AR低、高剂量组及N-乙酰半胱氨酸(NAC)治疗组,每组各8只。其中AR低、高剂量组分别以50、75 mg/kg的AR灌胃,NAC组以100 mg/kg灌胃,每日1次,共3 d。第4天,除对照组外,其余各组以350 mg/kg剂量APAP灌胃,12 h后处死全部小鼠,收集血清及肝组织。检测血清ALT、AST活性;HE染色观察肝组织病理学变化;免疫组化染色观察肝组织髓过氧化物酶(MPO)、瞬时受体电位M2型离子通道(TRPM2)表达。体外实验以不同剂量APAP(0、5、10、20 mM)孵育AML12细胞12、24 h,筛选出APAP肝细胞损伤最佳浓度和作用时间,并动态检测肝细胞TRPM2基因及蛋白表达。肝细胞分为对照组,模型组,AR低、高剂量组及NAC对照组,除对照组外,其余各组以20 mM APAP诱导损伤,并分别以125、250μg/mL的AR、50 mM NAC孵育24 h。采用CCK8检测细胞活力,qRT-PCR检测肝细胞TRPM2基因表达、Western Blot检测蛋白表达。结果 与对照组比较,APAP可诱导急性DILI,血清ALT、AST活性明显升高(F=35.717、F=18.997,P值均<0.01),肝组织结构破坏严重、肝细胞大块/亚大块坏死、中央静脉淤血;与模型组相比,AR能显著降低模型小鼠血清ALT、AST活性,减轻肝细胞坏死、肝组织MPO及TRPM2表达,具有明显的保肝作用,且AR高剂量组与NAC疗效相当。5 mM APAP孵育AML12细胞24 h明显诱导肝细胞损伤,且肝细胞TRPM2表达随着时间的延长而增加(F=25.408,P<0.01);与模型组相比,AR可提高肝细胞活力、降低肝细胞TRPM2表达。结论 黄芪提取物具有良好的保护APAP诱导急性DILI作用,其机制与抑制TRPM2表达相关。

儿童原发性肾病综合征血清PLCE1、TRPC6、CD2AP、ACTN4检测的意义

目的探讨检测外周血磷脂酶CE1(PLCE1)、瞬时受体电位阳离子通道蛋白6(TRPC6)、CD2相关蛋白(CD2AP)、α-辅肌动蛋白4(ACTN4)在儿童原发性肾病综合征(PNS)、激素敏感型肾病综合征(SSNS)、激素耐药型肾病综合征(SRNS)、激素依耐型肾病综合(SDNS)及不同病理类型表达的临床意义。方法采集原发性肾病综合征外周血清标本,采用双抗体夹心ELISA法检测样本中目PLCE1、TRPC6、CD2AP、ACTN4表达浓度。结果PNS组、SSNS组、SRNS组、SDNS组PLCE1、TRPC6、CD2AP、ACTN4表达与健康组比较降低,差异均有统计学意义(P<0.05),SRNS组、SDNS组表达与SSNS组比较降低,差异均有统计学意义(P均<0.05),SRNS组与SDNS组比较差异均无统计学意义(P>0.05);FSGS组、IgAN组血清PLCE1、TRPC6、CD2AP、ACTN4表达与MCD组比较降低,差异均有统计学意义(P<0.05),FSGS组、IgAN组分别与MsPGN组、MPGN组比较降低,差异均有统计学意义(P<0.05),MsPGN组与MPGN组比较差异无统计学意义(P>0.05),FSGS组与IgAN组比较差异无统计学意义(P>0.05)。结论①血清中PLCE1、TRPC6、CD2AP、ACTN4作为足细胞裂孔隔膜分子、足细胞信号分子、骨架分子等正常表达,对维系肾小球滤过膜的功能完整性起关键作用,一旦表达异常降低,可能导致肾病综合征发生、对激素治疗耐药或依耐;②血清中PLCE1、TRPC6、CD2AP、ACTN4表达与肾病综合征病理类型有关;③临床上检测血清中PLCE1、TRPC6、CD2AP、ACTN4表达水平对判断是否为难治性肾病、病理类型、指导用药及预测预后具有重大意义。

TRPC1与BK-α的表达对大鼠糖尿病肾病的影响

目的 探究瞬时受体电位C1(transient receptor potential channel 1,TRPC1)蛋白和大电导钙离子激活钾通道α亚单位(large conductance Ca^(2+)-activated K^(+)channel α subunit,BK-α)蛋白对大鼠糖尿病肾病(diabetic kidney disease,DKD)的影响。方法 将SD大鼠随机分为对照组(n=15)和模型组(n=15)。利用高脂饲料和链脲佐菌素(streptozocin,STZ)构建DKD模型。采用血糖分析仪检测大鼠血糖变化;采用全自动生化分析仪检测大鼠肾功能水平;HE染色检测肾组织的病理变化以确定造模成功。实时荧光定量PCR(RT-qPCR)和蛋白免疫印迹分别检测肾组织TRPC1和BK-α的mRNA和蛋白表达水平;免疫组化检测TRPC1和BK-α的分布和表达情况。结果 模型组大鼠空腹血糖(fasting plasma glucose,FPG)、尿白蛋白排泄率(urinary albumin excretion rates,UAER)、血尿素氮(blood urea nitrogen,BUN)和肌酐(creatinine,Cr)均显著高于对照组(P <0.01);模型组大鼠肾小管内壁细胞出现膨胀现象,部分细胞脱离;可见肾小管发生病变或死亡;此外,在许多肾小管及肾间质区域发现有中性白细胞及其残骸;以上HE染色结果提示,DKD模型复制成功。TRPC1和BK-α在肾小球部位最为丰富,且模型组大鼠肾组织中TRPC1和BK-α的mRNA和蛋白水平都显著高于对照组(P <0.05)。结论 大鼠糖尿病肾病影响TRPC1和BK-α在肾组织中的分布和表达。

线粒体氧化应激及m6A表观遗传调控TRPC6钙通道在肾病综合征发病中的作用研究

目的 初步探讨N6-甲基腺嘌呤(m6A)表观遗传修饰瞬时受体电位阳离子通道6(TRPC6)通道失调在肾病综合征发病中的作用及潜在机理。方法 按照随机数字表法将小鼠足细胞分为4组:对照组、叔丁基对苯二酚(TBHQ)组、嘌呤霉素氨基核苷(PAN)处理组、TBHQ+PAN处理组。对照组为正常完全培养液,TBHQ组培养液中加入10 nmol/L TBHQ,PAN处理组培养液中加入PAN 50μg/mL,TBHQ+PAN处理组培养液中加入10 nmol/L TBHQ以及PAN 50μg/mL,刺激24 h收集细胞。应用膜片钳证实PAN损伤诱导TRPC6通道激活机理及1,4,5-肌醇三磷酸(IP3)受体拮抗剂TBHQ对电流的影响,检测对照组、PAN处理组、TBHQ组和TBHQ+PAN处理组细胞TRPC6通道电流变化。通过葡萄糖氧化酶(GO)建立足细胞氧化应激模型。另外按照随机数字表法将足细胞分为4组:空白对照组、GO组、姜黄素组、姜黄素+GO组。GO组给予GO 3.5 kU/L,姜黄素组给予Nrf2激动剂(姜黄素)40μmol/L,姜黄素+GO组给予姜黄素40μmol/L和GO 3.5 kU/L处理,给药处理8~12 h后收集细胞。检测各组Nrf2和特异性调控蛋白NAD(P)H:醌氧化还原酶1(NQO-1)、TRPC6及Transgelin蛋白和线粒体调控蛋白表达变化。通过SRAMP对TRPC6通道m6A位点进行精准预测,对PAN诱导足细胞损伤模型公共数据库GSE124622进行2次生物信息学分析。结果 对照组与TBHQ组电流比较,差异无统计学意义(P>0.05);与对照组比较,PAN处理组电流升高,而TBHQ+PAN组电流减小,差异均有统计学意义(P<0.05)。与空白对照组比较,GO组Nrf2、NQO-1、TRPC6及Transgelin蛋白表达均升高,差异均有统计学意义(P<0.01);与GO组比较,姜黄素+GO组Nrf2、NQO-1、TRPC6及Transgelin蛋白表达均降低,差异均有统计学意义(P<0.05)。与空白对照组比较,GO组线粒体调控蛋白Mfn2、Opa1蛋白表达均降低,Drp1蛋白表达升高,差异均有统计学意义(P<0.05);与GO组比较,姜黄素+GO组粒体调控蛋白Mfn2、Opa1蛋白表达升高,Drp1蛋白表达降低,差异均有统计学意义(P<0.05);空白对照组与姜黄素组TRPC6/Transgelin及线粒体调控蛋白表达比较,差异均无统计学意义(P>0.05)。TRPC6通道序列存在多个m6A修饰位点,均具有被甲基转移酶(METTL)3、METTL14、肾母细胞肿瘤1相关蛋白(WTAP)和去甲基化酶ALKB同源蛋白(ALKBH)、m6A去甲基化酶(FTO)调控的潜在可能。对12个m6A调节基因进行表达分析,发现m6A调节基因的表达在PAN诱导足细胞损伤中发生显著差异。结论 TRPC6介导钙离子内流可被氧化应激激活参与足细胞损伤,激活Nrf2可以减少钙过负荷所致线粒体损伤而保护足细胞。TRPC6序列中存在多个高m6A修饰靶点,肾病综合征发病机理可能通过m6A修饰足细胞TRPC6离子通道,m6A相关调控基因在肾病足细胞损伤中发生明显变化。

桔梗素D通过下调成纤维细胞TRPC6表达改善小鼠肺纤维化

目的探究桔梗素D(PD)对肺纤维化的影响及其机制。方法博来霉素(BLM)气道内滴入构建C57BL/6J小鼠肺纤维化模型,再予PD(10 mg/kg)灌胃,28 d后处死小鼠。分组如下:对照组(control)、BLM(10 mg/kg)模型组、BLM(10 mg/kg)+PD(10 mg/kg)组。肺组织石蜡切片HE染色、免疫组化和天狼星红染色评估小鼠肺组织纤维化程度和瞬时受体电位离子通道亚族C成员6(TRPC6)的表达与分布。Westernblot检测肺组织α-平滑肌肌动蛋白(α-SMA)的表达水平。小鼠原代肺成纤维细胞体外培养,分别用PD、TRPC6抑制剂醋酸落叶松酯(LA)预处理后加入转化生长因子-β1(TGF-β1)刺激细胞,根据加入的TGF-β1和PD浓度不同分组如下:control组、TGF-β1(10 ng/mL)组、PD(2.5μmol/L)+TGF-β1组、PD(5μmol/L)+TGF-β1组和PD(10μmol/L)+TGF-β1组,LA处理分组如下:control组、TGF-β1(10 ng/mL)组和LA(10μmol/L)+TGF-β1组,测定细胞存活率、collagenⅠ、α-SMA和TRPC6的表达水平、活性氧(ROS)生成水平、线粒体膜电位、细胞增殖能力等指标。利用网络药理学方法结合文献分析PD作用于肺纤维化可能通过的机制。结果PD可明显减轻BLM诱导小鼠模型的肺部纤维化程度、减少α-SMA表达(P<0.05)。CCK-8结果显示PD、TGF-β1和LA的最适宜刺激浓度分别是10μmol/L、10 ng/mL和10μmol/L;5-乙炔基-2'-脱氧尿苷(EdU)染色结果显示PD能够有效抑制肺成纤维细胞增殖;2,7-二氯荧光素二乙酸酯(DCFH-DA)染色显示PD能有效减少TGF-β1诱导的细胞ROS生成(P<0.0001);线粒体膜电位检测(Jc-1染色)结果显示PD能有效缓解TGF-β1诱导的细胞线粒体膜电位下降(P<0.001);蛋白电泳结果显示PD能显著抑制TGF-β1诱导的α-SMA和collagenⅠ的表达(P<0.05)。网络药理学结合文献分析发现PD可能通过TRPC6作用于肺纤维化。免疫组织化学结果显示PD明显减轻了BLM诱导的肺组织TRPC6表达。蛋白电泳结果显示PD可明显抑制TGF-β1诱导的TRPC6表达(P<0.05);使用LA可明显抑制细胞TRPC6、α-SMA、collagenⅠ的表达(P<0.05)。结论PD可降低小鼠肺纤维化,其机制可能与下调TRPC6并减少ROS产生有关。

TRPM2离子通道在H9N2流感病毒感染小鼠肺微血管内皮细胞线粒体损伤中的作用

旨在探讨瞬时电位受体M2离子通道(TRPM2)在H9N2流感病毒感染小鼠肺微血管内皮细胞(PMVEC)导致线粒体损伤过程中的作用。在已建立TRPM2 shRNA PMVEC的基础上,采用5MOI H9N2猪流感病毒感染细胞,在病毒作用后24和48 h提取各组细胞的线粒体进行蛋白定量,检测各组细胞线粒体超氧化物歧化酶(SOD)、谷胱甘肽(GSH)、一氧化氮合成酶(NOS)、线粒体呼吸链复合物Ⅳ活性和ATP酶水平;利用激光共聚焦显微镜观察线粒体膜电位变化(JC-1染色)及细胞凋亡(Annexin V-FITC/PI双染色法)情况。结果表明:H9N2-SIV感染后TRPM2 shRNA PMVEC内SOD活性、GSH水平和Na^+-K^+-ATP、线粒体呼吸链复合物Ⅳ活性显著高于对照shRNA PMVEC(P<0.05或P<0.01);mtNOS活性则极显著低于shRNA PMVEC(P<0.01)。JC-1染色显示TRPM2-siRNA PMVEC线粒体膜电位水平高于对照shRNA PMVEC,但是AnnexinV-FITC/PI染色显示细胞凋亡则低于H9N2感染对照shRNA PMVEC。结果提示:TRPM2基因沉默有效减缓H9N2感染导致NOS产生,显著降低SOD、GSH、线粒体呼吸链复合物Ⅳ、Na^+-K^+-ATP的消耗以及线粒体膜电位的下降程度,进而有效缓解PMVEC线粒体损伤及细胞凋亡。