title: [Effect of nanobacteria on cell damage and crystal retention in renal tubular epithelial cells].
abstract: OBJECTIVE
  To study the damage of nanobacteria on HK-2 cells, the possible principles, the effect of crystals (COM) adhering to HK-2 cells after the damage.
  
  
  METHODS
  Four groups were chosen for the study: control group, NB group, nHAP group and COM group. Morphological changes of the HK-2 cells were observed after HE stain and with TEM after 12 hours and 24 hours. Meanwhile, the levels of H2O2, LDH, MDA and ATPases were surveyed after 6 hours,12 hours and 24 hours, respectively. And 6, 12, and 24 hours later, COM crystals were mixed into the culture fluids of each group. Then phalloidin-FITC was used to finish fluorescent staining of the cells. At last, the adhering effects of each group with the laser scanning confocal fluorescence microscope were observed and contrasted.
  
  
  RESULTS
  After HE stain and with TEM: in NB and nHAP group, the shape of the cells changed, brush borders were arranged in disorder, vacuoles formed in the kytoplasms, the mitochondria became swelled up, the karyotheca dissolved and the nucleolus disappeared in some cells. After 24 hours, in NB group, the number of the cells in which the karyotheca dissolved was more than that in nHAP group. After 12 and 24 hours, the level of H2O2 in NB group was higher than that in control group and nHAP group; After 6 and 24 hours, the level of MDA in NB group was higher than that in control group and nHAP group; At each time point, there was no significant difference in the level of LDH between control group, nHAP group and NB group; After 12 hours, the activities of Na+/K+ ATPases in NB group and nHAP group were lower than those in control group. And after 24 hours, the activity of Na+/K+ ATPases in NB group was lower than that in control group; After 12 and 24 hours, the activities of Ca2+/Mg2+ ATPases in NB group was lower than those in control group. After 12 hours, the activity of Ca2+/Mg2+ ATPases in nHAP group was lower than that in control group. The observation with the laser scanning confocal fluorescence microscope: after 12 hours, showed that the number of the crystals adhering to the cells in NB group and COM group increased, and in COM group, some crystals had entered the cells; after 24 hours, the adhering effects of the crystals in NB and COM group were similar to those after 12 hours, but the number of adhered crystals was more than that after 12 hours; At each time point, there was no significant change in control and nHAP groups.
  
  
  CONCLUSIONS
  Nanobacteria has a damage effect on HK-2 cells, the damage increases with the acting time expanding. The damage is more severe than that of nHAP. In the damage process of nanobacteria, the lipid peroxidation may play an important role. After the damage of nanobacteria, the adhering effect of the COM crystals to the cells increases observably, and the number of crystals adhering to the cells becomes more and more with the acting time expanding. Although nHAP also has a damage effect on HK-2 cells, it does not effect the adhering process.
authors: Department of Urology, Peking University People's Hospital, Beijing 100034, China.
authors: Cheng-fan
authors: CF
authors: Yu
authors: Xiao-bo
authors: XB
authors: Huang
authors: Liang
authors: L
authors: Chen
authors: Qing-quan
authors: QQ
authors: Xu
authors: Wei-guo
authors: WG
authors: Hu
authors: Xiao-feng
authors: XF
authors: Wang
mesh_terms: D000818:Animals; D001419:Bacteria / Q000302:isolation & purification*; D002129:Calcium Oxalate / Q000737:chemistry; D002460:Cell Line; D003460:Crystallization; D004847:Epithelial Cells / Q000473:pathology*; D006801:Humans; D006882:Hydroxyapatites / Q000737:chemistry; D007669:Kidney Calculi / Q000209:etiology / Q000382:microbiology*; D007684:Kidney Tubules / Q000382:microbiology / Q000473:pathology*; D053758:Nanoparticles; D051381:Rats
chemical_list: D006882:Hydroxyapatites; D002129:Calcium Oxalate