A Proteomic Network Approach across the Kidney Stone Disease Reveals Endoplasmic Reticulum Stress and Crystal-Cell Interaction in the Kidney

Figure 4

The effect of ER stress on crystal-cell interaction. (a) ER stress promoted crystal-cell adhesion. In the TM+COM group, the HK2 cells were treated with COM crystals for five minutes after exposing TM, an inducer of ER stress, for 24 hours. The COM crystals that adhered to the cells were lysed with 5 ml of 6 M HCl. A quantitative analysis of the COM crystals was conducted, by measuring the concentration using an atomic absorption method. Crystal adhesion in the TM+COM group rose significantly compared with the COM group (), and SAL reversed it (). SAL also reduced crystal-cell adhesion after exposure to COM crystals (). (b) ER stress induced by TM affected the expression of proteins associated with the formation of a kidney stone. Protein expression showed a similar trend between TM exposure and COM exposure. , , and vs. 0 h. (c) ER stress induced by TM reduced cell viability, and SAL reversed it in vitro. HK2 cells were exposed to 100 μg/ml COM crystals and 1 μg/ml TM for two days, respectively. COM crystals and TM significantly reduced cell viability (). HK2 cells were exposed to 100 μg/ml COM crystals and 1 μM SAL+100 μg/ml COM crystals for two days, respectively. SAL significantly increased cell viability compared with the group of COM crystals (). (d) The number of cells was compared to that of the group of COM and the group of COM+SAL for 12, 24, and 48 hours. The number of cells in the COM+SAL group significantly increased at 24 hours (). TM represented tunicamycin. SAL represented salubrinal.

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