镉对大鼠肾小管上皮细胞的毒性作用及NAC的保护效应
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
镉是环境中常见的重金属污染物,由于工业生产中镉使用量的增加及相关工业废物带来的污染加重,环境中的镉含量呈快速上升趋势,给公众健康带来的危害引起了广泛关注。肾脏是慢性镉毒性损伤的靶器官和蓄积部位,国内外研究者从职业性暴露、环境污染及动物试验多方面对镉所致肾毒性机理进行了广泛研究。本研究以SD大鼠为试验动物,通过体外培养细胞的方法探讨了镉对大鼠肾小管上皮细胞的毒性损伤效应及N-乙酰半胱氨酸(NAC)的保护效应,为进一步认识镉的肾毒性作用提供了理论依据。
     本试验采用机械筛网结合酶消化法建立大鼠原代肾小管上皮细胞培养模型,在传一代细胞增殖活性最强时间段进行镉(2.5μmol/L、5μmol/L)染毒。主要进行以下试验:①cck-8还原法测定不同组合的镉在不同染毒时间(3、6、12、24h)对rPTCs存活率的影响;②测定镉染毒12h对rPTCs凋亡率、坏死率、乳酸脱氢酶释放率、细胞内GSH水平及凋亡形态学的影响,同时添加NAC,观察其对镉所致细胞毒性损伤的保护效果;③测定镉染毒12h对rPTCs膜ATP酶(Ca2+-ATPase、Na+/K+-ATPase)活性、胞内pH、线粒体膜电位、活性氧及钙离子水平的影响。
     结果表明:①5μmol/LCd组从6h开始、2.5μmol/LCd组从12h开始,其细胞存活率显著低于对照组(P<0.05或P<0.01),且存活率降低幅度与染毒剂量、染毒时间呈正相关;②染毒12h,各染毒组细胞凋亡率、坏死率、乳酸脱氢酶释放率均极显著高于对照组(P<0.01);染毒组细胞表现核皱缩、呈新月形、染色质致密浓染、核碎裂等典型凋亡特征;NAC对镉所致细胞凋亡有显著保护效应,但对细胞坏死率和乳酸脱氢酶释放率无明显影响;③与对照组比较,染毒组GSH含量均极显著降低(P<0.01),NAC有显著保护效应;④染毒各组细胞内活性氧和钙离子水平均极显著高于对照组(P<0.01),线粒体膜电位水平、胞内pH、Ca2+-ATPase与Na+/K+-ATPase活性均极显著低于对照组(P<0.01)。
     上述试验结果可以得出以下结论:①镉暴露对rPTCs的毒性损伤呈浓度依赖性和时间依赖性;②细胞凋亡与细胞坏死是镉所致rPTCs死亡的2种死亡类型,其中凋亡性死亡在低剂量镉所致细胞损伤过程中发挥主导作用。氧化应激在镉染毒所致细胞凋亡型死亡过程中发挥重要作用,抗氧化剂NAC对镉所致的肾小管上皮细胞毒性损伤有显著保护效应;③镉暴露导致rPTCs线粒体膜电位降低而促进细胞凋亡,同时细胞内酸化、钙离子超载、氧化还原平衡状态失调等一系列细胞内环境稳态失衡促进了细胞凋亡。
Cadmium (Cd) is now recognized to be one of most important heavy metal contaminants in the environment. Due to its increased industrial uses and environmental pollution with the related waste products, concentrations of cadmium is increasing rapidly in the environment in recent years. Adverse health effects caused by cadmium have provoked a significant public health concern. The kidney is the target organ and the primary accumulation site of chronic cadmium exposure. The nephrotoxicity induced by cadmium has been extensively studied and widely reported in occupationally and environmentally exposed human subjects, as well as in various experimental models. In this study, the toxic effects of cadmium on the kidney of Sprague-Dawley (SD) rats were investigated in vitro, which will offer some theoretic evidences for further exploring the mechanism in nephrotoxicity of cadmium.
     In studies, the primary cultures of rat proximal tubular cells (rPTCs) were cultured by mechanical grinding, filtering and chemical digestive methods. The first passage was used to perform the experimental design when it was in its highest cell viability.
     Effects of cadmium (2.5μmol/L, 5μmol/L) on the rPTCs were investigated in the following assays.①Effects of different doses of lead and/or cadmium on the survival rates in rPTCs for a time range of 3, 6, 12 and 24h were detected by using the cck-8 reduction method.②Effects of cadmium on the apoptotic rates, necrotic rates, LDH release, contents of GSH and apoptotic morphological changes in rPTCs over a 12h period were investigated. In addition, the protective effect of N-acetyl-L-cysteine (NAC) against cadmium induced cellular damage was investigated.③Activities of Ca2+-ATPase and Na+/K+-ATPase, intracellular pH, levels of mitochondrial membrane potential (ΔΨ), reactive oxygen species (ROS) and intracellular [Ca2+]i in rPTCs were detected after exposed to lead and/or cadmium for 12h.
     The results are as follows:①The cell survival rates in the cadmium groups were significantly lower than those of control groups since these cells were exposed to high-dose (5μmol/L) and low-dose (2.5μmol/L) groups for six and twelve hours, respectively (P<0.05 or P<0.01). Furthermore, the degree of decrease in the cell survival rate was positively correlated with the dose and the exposure time.②After exposure to cadmium for 12h, the apoptotic rates, necrotic rates, LDH release in these exposed groups were significantly higher than those in the control group (P<0.01). After a 12h exposure time, it showed typical apoptotic features in the cadmium groups, i.e., nuclear chromatin condensed and fragmented chromatin was characterized by a scattered, drop-like structure. Apoptosis induced by cadmium can be efficiently prevented by NAC, but the necrotic rates and LDH release were not affected by NAC.③Compared with the control group, activities of the GSH level in the exposed groups decreased significantly (P<0.01), and it can be efficiently prevented by NAC.④After exposed to cadmium for 12h, intracellular ROS and [Ca2+] in rPTCs increased significantly (P<0.01), while the mitochondrialΔΨ, intracellular pH, activities of Ca2+-ATPase and Na+/K+-ATPase decreased significantly (P<0.01). Based on these results, the conclusions are as follows:①cadmium exposure induced cellular death in rPTCs, depending on both the concentration and the exposure time.②Cellular death induced by cadmium is medicated by two mechanisms, necrotic and apoptotic. The apoptotic mechanism played a chief role in the cellular death induced by cadmium at these doses. Moreover, oxidative stress could be implicated in the apoptotic mechanism mediated by cadmium. In addition, the cellular damage induced by lead and/or cadmium can be significantly prevented by NAC.③Depletion of mitochondrialΔΨand a disorder of intracellular homeostasis, i.e. intracellular acidification, calcium overload, disturbance in the prooxidant–antioxidant balance, promoted the development of apoptosis in rPTCs.
引文
[1] Elinder CG, Kjellstrom T, Lind B, etal. Cadmium exposure from smoking cigarettes: variations with time and country where purchased. Environ Res, 1983, 26: 1221
    [2]刘杰,镉的毒性和毒理学研究进展.[J].中华劳动卫生职业病杂志,1998,16(1):57-59
    [3] Nordberg GF. Cadmium in the Human Envirment, Toxicity and Carcinogencity [M]. Lyon IARC, 1992: 3
    [4] Jie Liu, Yaping Liu, Sultan S. Habeebu, and Curtis D. Klaassen Susceptibility of MT-Null Mice to Chronic CdCl2-Induced Nephrotoxicity Indicates That Renal Injury Is Not Mediated by theCd-MT Complex, Toxicol, Sci. November 1998: 46, 197-203
    [5]刘杰,刘亚平.慢性和急性染镉所致小鼠肾损伤的比较.[J].中华劳动卫生职业病杂志,1998,16(1):9-11
    [6] El Azzouzi B, Tsangaris GT, Pellegrini O, Manuel Y, Benveniste J, and Thomas Y. Cadmium induces apoptosis in a human T cell line. Toxicology, 1994(88): 127-139
    [7] John D, Robertson, Sten Orrenius. Molecular mechanisms of apoptosis induced by cytotoxic chemicals.[J]. Critical Review inToxicology. 2000, 30(5): 609-627
    [8]尹海林,彭黎明,王曾礼主编.细胞凋亡的调控[A],细胞凋亡的基础与临床[M].北京:人民卫生出版社,2000,112-145
    [9] E1 Azzouri B, TsangarisGT, Pellegrini O, et al. Cadmium induces apoptosis in a human T cell lines.[J]. Toxicology, 1994, 88(1-3): 127-389
    [10] Matsuoka M, Call KM. Cadmium-induced expression of immediate early genesin LLC-DK1 cells.[J]. Kidney Int, 1995, 48(2): 383-389
    [11] Hamado T, Tanimoto A, Iwal S, et al. Cytopathological changes induced by cadmium-expossure in canine proxima; tubular cells: a cytochemical and ult-trastructureal study.[J]. Nephron, 1994, 68(1): 104-111
    [12] Xu GG, Zhou GO, Jin TY, et al. Apoptosis and P53 gene expression in malereproductive tissues of cadmium exposed rats.[J]. Biometals, 1998, 12: 131-139
    [13]赵敏,杨杏芬,魏青等.氯化镉诱发肾上腺皮质细胞凋亡与应激活化蛋白激酶活性的研究.[J].中华预防医学杂志. 2000,34(6):342-344
    [14] Achanzer WE, Achanzar KB, Lewis JG, et al. Cadmium induces c-myc and c-jun expression inHuman Prostate Epithelial Cells as a prelude as a prelude to apoptosis.[J]. Toxicol Appl Pharmacol, 2000, 164(3): 291-300
    [15] Ding W, Templeton DM. Activation of parallel mitogen-activated protein ki-nase cascades and induction of c-fos by cadmium.[J]. Toxicol Appl Pharma-col, 2000, 162(2): 93-99
    [16] Yuan C, Kadiiska M, Achanzar WE, et al. Possible role of caspase-3 inhibi-tion in cadmium-induced blockage of apoptosis.[J]. Toxicol Appl Pharmacol, 2000, 164(3): 321-329
    [1]金建年,彭文娟,彭兆麟.痰净雾化液超声雾化吸入祛痰作用研究[J].湖北中医杂志,1999,21(4):157
    [2]李长生,杨炯,李清泉,等.乙酞半胧氨酸胶囊在咳祛痰作用的临床研究[J].中国医院药学杂志,1999,19(11):676
    [3] GregoryS,KellyND.Clinical APPlications of N-acetyl-cysteine[J].AltemMedRe1998,3:114
    [4]代心平.N-乙酞半胱氨酸药理与保健作用研究[J].海南医学,2004,12(10):121-122
    [5] LaileyAF. Oral N-acetyl-L-cysteine Protects against perfluoroisobutene toxieity in rats[J].Hum ExPToxieol, 1997,16: 212-216
    [6]王雨,徐兆发,喻道军,等. N-乙酞半眺氨酸和亚硒酸钠对镉亚慢性毒性的影响[J].毒理学杂志,2005,19(4):251-253
    [7] UelandPM, MansoorMA, GuttormsenAB, etal. Reduced oxidized and Protein-bound form of homoeysteine and other aminothiol in Plasma comprise the redox thiol status- Possible element of the extracelluar antioxidant defense system[J]. J Nutr, 1996, 126(4Suppl):1281
    [8] LabibR, Abdel-RahmanM, TurkallR. N-acetyl-cysteine Pretreatment decreases cocaine and endotoxin-induced hepatotoxicity[J]. J toxicol environ health, 2003, 66(3): 223-239
    [9] BuhimsehiLA, BuhimschiCS, WeinerCP. Protective effect of N-acetyl-cysteine against fetal death and preterm labor induced by maternal inflammation[J]. Am J obstet gynecol, 2003, 188(l): 203-208
    [10] AllegraL, DalSassoM, BovioC, etal. Human neutrophil oxidative bursts and their in vitro modulation by different N-acetyl-cysteine eoneentrations[J]. Arzneimittelforschung, 2002, 52(9): 669-676
    [11] DiekCA, BrownDM, DonaldsonK.The role of free radicals in the toxic and inflammatory effects of four different ultrafine particle types[J]. Inhat Toxicol, 2003, 15(l): 39-52
    [12] CammerW. Protection of cultured oligodendrocytes against tumor necrosis factor-alpha by the antioxidants coenzyme Q(10) and N-acetyl-cysteine[J]. BrainResBull, 2002, 58(6): 587-592
    [13] MalinsDC, HellstromKE, AndersonKM. Antioxidant induced changes in oxidized DNA[J]. Proc Natl Acad Sci USA, 2002, 99(9): 5937-5941
    [14] ReeehioniR, MarcheselliF, MoroniE etal. Apoptosis in human aortic endothelial cells induced by hyperglycemic condition involves mitochondrial depolari Zation and is prevented by N-acetyl-L-cysteine[J]. Metabolistn, 2002, 51(11): 1384-1388
    [15] DeFloraS, IzzottiA, D’AgostiniF, etal. Meehanisn of N-acetyl-cysteine in the Prevention of DNA damage and cancer, with special reference to smoking-related end-Points[J].Carcinogenesis,2001, 22(7): 999
    [1] Pieter J, Boogaard J, Paul Z, etal. Primary culture of proximal tubular cells from normal rat kidney as an in vitro model to study mechanisms of nephrotoxicity: Toxicity of nephrotoxicants at low concentrations during prolonged exposure.[J]. Biochemical Pharmacology, 1990, 39(8): 1335-1345
    [2] Pieter J, Boogaard J, Fred N, etal. Renal proximal tubular cells in suspension or in primary culture as in vitro models to study nephrotoxicity.[J]. Chemico-Biological Interactions, 1990, 76(3): 251-291
    [3] Foidart, Willems J, Dechenne C, etal. Biosynthesis of basement membrane collagen in culture of renal glomerular and tubular epithelial cells.[J]. Diabete Metab. 1975, 1(4) : 227-234
    [4] Rudolfs K, Zalups, Lawrence H, etal. Methods in renal toxicology.[M]. Canada, crc press, 1996
    [5]郑丰,黎磊石.大黄对体外肾小管细胞增殖的影响[J].医学研究生学报,1991,3(4):46
    [6]王东,吴雄飞,金锡御.大鼠肾小管上皮细胞的原代培养及传代[J].中华实用外科杂志,1999,16(2):179-180
    [7]刘晓玲,邢淑华. Percoll法分离培养肾小管上皮细胞[J].徐州医学院学报,2006,26(2):100-103
    [8] Lawrence H, Lash. In Vitro methods of assessing renal damage[J]. Toxicologic Pathology, 1998,26(1): 33-42
    [9]王洪复.骨细胞图谱与骨细胞体外培养技术[M].上海:上海科学技术出版社,2001
    [10] Toutain H, Vauclin-Jacques N, Fillastre J P, etal. Biochemical, functional, and morphological characterization of a primary culture of rabbit proximal tubule cells.[J]. Exp Cell Res, 1991, 194(1): 9-18
    [11]严玉澄,钱家麒,戴慧莉等.人近端肾小管上皮细胞的原代培养[J].上海第二医科大学学报,2005,25(4):388-390
    [12] Mattila P M, Nietosvaara Y A, Ustinov J K, etal. Antigen expression in different parenchymal cell types of rat kidney and heart [J]. Kid Int, 1989, 36(4): 228-233
    [1] Waisberg M, Joseph P, Hale B, Beyersmann D (2003) Molecular and cellular mechanisms of cadmium carcinogenesis. Toxicology 192: 95-117
    [2] Morales AI, Vicente-Sánchez C, Sandoval JM, Egido J, Mayoral P, Arévalo MA, Fernández-Tagarro M, López-Novoa JM, Pérez-Barriocanal F (2006) Protective effect of quercetin on experimental chronic cadmium nephrotoxicity in rats is based on its antioxidant properties. Food Chem Toxicol. 44: 2092-2100
    [3] Thévenod F, Friedmann JM (1999) Cadmium-mediated oxidative stress in kidney proximal tubule cells induces degradation of Na+/K+-ATPase through proeasomal and endo-/lysosomal proteotic pathway. The FASEB Journal 13: 1751-1761
    [4] Pari L, Murugavel P (2007) Diallyl tetrasulfide improves cadmium induced alterations of acetylcholinesterase, ATPases and oxidative stress in brain of rats. Toxicology 234: 44-50
    [5] Thévenod F (2003) Nephrotoxicity and the proximal tubule. Insights from cadmium. Nephron Physiol 93: 87-93.
    [6] Alvarez-Barrientos A, O’Connor JE, Nieto Castillo R, Moreno Moreno AB, Prieto P (2001) Use of low cytometry and confocal microscopy techniques to investigate early CdCl2-induced nephrotoxicity in vitro. Toxicol in Vitro 15: 407-412
    [7] LemariéA, Lagadic-Gossmann D, Morzadec C, Allain N, Fardel O, Vernhet L (2004) Cadmium induces caspase-independent apoptosis in liver Hep3B cells: role for calcium in signaling oxidative stress-related impairment of mitochondria and relocation of endonuclease G and apoptosis-inducing factor. Free Radic Biol Med. 36: 1517-1531
    [8] Li M, Kondo T, Zhao QL, Li FJ, Tanabe K, Arai Y, Zhou ZC, Kasuya M (2000) Apoptosis induced by cadmium in human lymphoma U937 cells through Ca2+-calpain andcaspase-mitochondria-dependent pathways[J]. Biol Chem 275: 39702-39709
    [9] CHIN T A, TEMPLETON D M. Effects of CdCl2 and Cd-metallothionein on cultured mesangial cells[J]. Toxicol Appl Pharmacol,1992,116: 133-141
    [10]赵斌,葛金芳,朱娟娟等.小议在MTT法测细胞增殖抑制率中IC50的计算方法[J].安徽医药,2007,11(9):834-836
    [11] Vermes I, Haanen C, Steffens-Nakken H, et al. A novel assay for apoptosis, flow cytometric detection of phosphatidylserine expression on early apoptotic cells using fluorescein-labeled Annexin V [J]. J Immunol Meth, 1995, 184: 39-51
    [12] Liu Y, Zhang SP, Cai YQ. Cytoprotective effects of selenium on cadmium- induced LLC-PK1 cells apoptosis by activating JNK pathway [J]. Toxicol in Vitro, 2007, 21: 677-684
    [13] Nordberg GF. Cadmium in the Human Enviroment , Toxicity and Carcinogencity [ M]. Lyon : IARC , 1992, 3
    [14]龚伟.铅、镉引起细胞死亡机理及硒抗铅、镉毒性效应的研究[D].北京:中国农业大学,1999
    [15] PATHAK N, KHANDELWAL S. Oxidative stress and apoptotic changes in murine splenocytes exposed to cadmium[J]. Toxicol, 2006, 220(1): 26-36
    [16] FOX D A, SRIVASTAVA D, POBLENZ A, et al. Lead-induced Alterations in Gene Expression and Activity of Retinal cGMP PDE Results in Calcium Overload and Rod-selective Apoptosis[J]. Toxicol in Vitro, 1998, 12: 597-598
    [17] PHAM TND, MARION M, DENIZEAU F, et al. Cadmium-induced apoptosis in rat hepatocytes does not necessarily involve caspase-dependent pathways[J]. Toxicol in Vitro, 2006, 20(8): 1331-1342
    [18]韩贻仁.分子细胞生物学[M].二版.北京:科学出版社,2003:648-661
    [19] Shabani A, Rabbani A. Lead nitrate induced apoptosis in alveolar macrophages from rat lung [J]. Toxicology, 2000, 149: 109-114
    [20] De la Fuente H, Portales-Perez D, Baranda L, et al.Effect of arsenic, cadmium and lead on the induction of apoptosis of normal human mononuclear cells [J]. Clin Exp Immunol, 2002, 129: 69-77
    [21] Lavrentiadou SN, Chan C, Kawcak T, et al. Ceramide-mediated apoptosis in lung epithelial cells is regulated by glutathione [J]. Am J Respir Cell Mol Biol, 2001, 25: 676-684
    [22] Patra RC, Swarup D, Dwidedi SK. Antioxidant effects ofαtocopherol, ascorbic acid and L-methionine on lead-induced oxidative stress of the liver, kidney and brain in rats [J]. Toxicology, 2001, 162: 81-88
    [23] Thijssen S, Cuypers A, Maringw J, et al. Low cadmium exposure triggers a biphasic oxidative stress response in mice kidneys [J]. Toxicology, 2007, 236(1): 29-41
    [24] Shaikh ZA, Vu TT, Zaman K. Oxidation stress as a mechanism of chronic cadmium-induced hepatotoxicity and renal toxicity and protection by antioxidants [J]. Toxicol Appl Pharmacol, 1999, 154: 256-263
    [25]夏世钧,吴中亮.分子毒理学基础[M].武汉:湖北科学技术出版社,2001:87-90
    [26]敖琳.细胞凋亡中Ca2+稳态失调机制的研究进展[J].国外医学分子生物学分册,2001,23(2):106-108
    [27]陶亮,关永源,贺华,等. HEK293细胞-一种研究受体Ca2+调控功能的理想模型[J].中国药理学通报,1998,14(3):220-223
    [28] LiM, KondoT, ZhaoQL, etal. Apoptosis Induced by Cadmium in Human Lymphoma U937 Cells through Ca2+-calpain and Caspase Mitochondria dependent Pathways[J]. JBiol Chem, 2000, 275: 39702-39709
    [29] Harnick DJ, Jayaraman T, Ma Y, etal. The human type 1 inositol 1,4,5-trisphosphate receptor from Tlymphocytes[J]. J Biol Chem, 1995, 270(6): 2 833-2840
    [30] CristinaF, BarbaraI, Tullio P. Receptor-activated Ca2+influx: how many mechanisms for how many channels[J]. Trends Pharmacol Sci, March 1, 1994, 15(3): 77-83
    [31] Dwyer SD, Zhuang Y, Smith JB. Calcium mobilization by cadmium ordecreasing extracellular Na+ orpHin coronary endothelial cells[J]. Exp Cell Res, 1991, 192(1): 22-31
    [32]郑倩,骆云鹏.钙稳态紊乱和细胞凋亡[J].川北医学院学报,2001, 16(4):142-144
    [33] Thevenod F, et al. [J ] . JBiol Chem, 2000, 275(3): 1887-1896
    [34]黄学文,唐秋莎,陈道桢等.原发性肝癌患者血清ROS、NO、SOD水平分析[ J ].临床检验杂志,2003, 21 (3),148-149
    [35] Trrens J F. Mitochondrial formation of reactive oxygen species[ J ]. J Physiol, 2003, 552 ( Pt2): 335-344
    [36] Djavaheri-MergnyM, Wietzerbin J, Besancon F, et al. 2-Methoxyestra-diol induces apoptosis inEwing sarcoma cells through mitochondrial hydrogen peroxide production [ J ]. Oncogene, 2003, 22(17): 2552-2567
    [37]吴治芬,金晓琳,刘盛华.慢性镉中毒肾功能损伤的研究[J].第三军医大学学报,1992(1)
    [38] Langdon RG.. Properties and mechanism of action of purified glutathione reduction [J]. Biochem Biophys Acta, 1958, 30: 432-433
    [39] Grimes A J. Human Red Cell Metabolism[M]. Oxford:Blackwell Scientific, 1980: 257

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700