Expression of hsp 27, hsp 60, hsc 70, and hsp 70 stress response genes in cultured human urothelial cells (UROtsa) exposed to lethal and sublethal concentrations of sodium arsenite.

The stress response is one mechanism that the bladder urothelium could potentially employ to protect itself from cellular damage after exposure to arsenic and, in so doing, influence the shape of the dose-response curve at low concentrations of exposure to this environmental pollutant. In the present study, we used the cultured human urothelial cell line UROtsa, a model of human urothelium, to determine the expression of heat shock proteins hsp 27, hsp 60, hsc 70, and hsp 70 after acute and extended exposure of the cells to lethal and sublethal levels of sodium arsenite (NaAsO2). Acute exposure was modeled by exposing confluent cultures of UROtsa cells to 100 micro M NaAsO2 for 4 hr followed by a 48-hr recovery period. Extended exposure was modeled by exposing confluent UROtsa cells to 1, 4, and 8 micro M NaAsO2 for 16 days, with the highest concentration producing cell death by 4 days of exposure. The expression of hsp 27, hsp 60, hsc 70, and hsp 70 mRNA and protein was determined by reverse-transcription polymerase chain reaction and Western analysis. Cell viability was determined by the MTT [(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The results demonstrated that the expression of hsp 27, hsp 60, and hsc 70 mRNA and protein were not consistently increased by either acute or extended exposure to NaAsO2. In contrast, hsp 70 expression was induced by NaAsO2 after both acute and extended exposure. The degree and duration of the induction of the hsp 70 protein in the extended time course of exposure to NaAsO2 correlated directly with UROtsa cell cytotoxicity. The substantial level of basal expression of hsp 27, hsp 60, and hsc 70 shown previously in human bladder urothelium, coupled with the inducible expression of hsp 70, could provide the human urothelium with a mechanism to withstand and recover from a low level of arsenite exposure.

[1]  J. Masters,et al.  Immortalisation of human urothelial cells , 2004, Urological Research.

[2]  J. Masters,et al.  Culture and characterisation of human urothelium in vivo and in vitro , 2004, Urological Research.

[3]  S. Garrett,et al.  EXPRESSION OF hsp 27, hsp 60, hsc 70, AND hsp 70 BY IMMORTALIZED HUMAN PROXIMAL TUBULE CELLS (HK-2) FOLLOWING EXPOSURE TO HEAT SHOCK, SODIUM ARSENITE, OR CADMIUM CHLORIDE , 2001, Journal of toxicology and environmental health. Part A.

[4]  S. Garrett,et al.  The immortalized UROtsa cell line as a potential cell culture model of human urothelium. , 2001, Environmental health perspectives.

[5]  K. Kitchin.  Recent advances in arsenic carcinogenesis: modes of action, animal model systems, and methylated arsenic metabolites. , 2001, Toxicology and applied pharmacology.

[6]  Luda Bernstam, Jerome Nriagu.  MOLECULAR ASPECTS OF ARSENIC STRESS , 2000, Journal of toxicology and environmental health. Part B, Critical reviews.

[7]  S. Garrett,et al.  Expression of heat shock protein 60 in human proximal tubule cells exposed to heat, sodium arsenite and CdCl2 , 2000 .

[8]  John I. Clark,et al.  Small heat-shock proteins and their potential role in human disease. , 2000, Current opinion in structural biology.

[9]  S. Garrett,et al.  Expression of heat shock protein 60 in human proximal tubule cells exposed to heat, sodium arsenite and CdCl(2). , 2000, Toxicology letters.

[10]  S. Garrett,et al.  Expression of the constitutive and inducible forms of heat shock protein 70 in human proximal tubule cells exposed to heat, sodium arsenite, and CdCl(2). , 1999, Environmental health perspectives.

[11]  S. Garrett,et al.  Heat shock protein 27 expression in human proximal tubule cells exposed to lethal and sublethal concentrations of CdCl2. , 1999, Environmental health perspectives.

[12]  U. Nseyo,et al.  Expression of Heat Shock Protein 60 Is Reduced in the Bladder of Patients with Interstitial Cystitis , 1999 .

[13]  A. Burger-Kentischer,et al.  Effect of ischemia on localization of heat shock protein 25 in kidney. , 1998, Kidney international. Supplement.

[14]  S. Garrett,et al.  Exposure of human proximal tubule cells to cd2+, zn2+, and Cu2+ induces metallothionein protein accumulation but not metallothionein isoform 2 mRNA. , 1998, Environmental health perspectives.

[15]  T. Tosteson,et al.  Design of an epidemiologic study of drinking water arsenic exposure and skin and bladder cancer risk in a U.S. population. , 1998, Environmental health perspectives.

[16]  Joshua T. Cohen,et al.  Likelihood Ratio Analysis of Skin Cancer Prevalence Associated with Arsenic in Drinking Water in the USA , 1998 .

[17]  A H Smith,et al.  Marked increase in bladder and lung cancer mortality in a region of Northern Chile due to arsenic in drinking water. , 1998, American journal of epidemiology.

[18]  Bernd Bukau,et al.  The Hsp70 and Hsp60 Chaperone Machines , 1998, Cell.

[19]  M. Kashgarian,et al.  Heat-shock protein 25 induction and redistribution during actin reorganization after renal ischemia. , 1998, American journal of physiology. Renal physiology.

[20]  K. Thurau,et al.  The response of heat shock proteins 25 and 72 to ischaemia in different kidney zones , 1997, Pflügers Archiv.

[21]  P. Ostrosky-Wegman,et al.  Arsenic: a paradoxical human carcinogen. , 1997, Mutation research.

[22]  C. Hopenhayn-Rich,et al.  Bladder Cancer Mortality Associated with Arsenic in Drinking Water in Argentina , 1996, Epidemiology.

[23]  Y. Hsueh,et al.  Incidence of internal cancers and ingested inorganic arsenic: a seven-year follow-up study in Taiwan. , 1995, Cancer research.

[24]  T. Tsuda,et al.  Ingested arsenic and internal cancer: a historical cohort study followed for 33 years. , 1995, American journal of epidemiology.

[25]  A. Macario,et al.  Heat-shock proteins and molecular chaperones: implications for pathogenesis, diagnostics, and therapeutics , 1995, International journal of clinical & laboratory research.

[26]  Elizabeth A. Craig,et al.  Heat shock proteins and molecular chaperones: Mediators of protein conformation and turnover in the cell , 1994, Cell.

[27]  M. Schlesinger.  How the Cell Copes with Stress and the Function of Heat Shock Proteins , 1994, Pediatric Research.

[28]  W. McGuire,et al.  Biological and clinical implications of heat shock protein 27,000 (Hsp27): a review. , 1993, Journal of the National Cancer Institute.

[29]  C. Georgopoulos,et al.  Role of the major heat shock proteins as molecular chaperones. , 1993, Annual review of cell biology.

[30]  F. Denizot,et al.  Rapid colorimetric assay for cell growth and survival. Modifications to the tetrazolium dye procedure giving improved sensitivity and reliability. , 1986, Journal of immunological methods.