Arsenic-Induced Injury of Mouse Hepatocytes through Lysosome and Mitochondria: An In Vitro Study

Figure 5

Onset of mitochondrial permeability transition (MPT) in isolated mouse hepatocytes due to arsenic exposure. Green fluorescence of calcein (a), red fluorescence of TMRM (b), and phase images (c) of the unfixed hepatocytes were imaged simultaneously by confocal microscopy, and images were represented after 4 h 15 min (i); 4 h 30 min (ii); 4 h 45 min (iii), and 5 h (iv) of arsenic exposure. In the baseline images, green fluorescence of calcein was limited to the cytosol and nucleus, whereas red fluorescence of TMRM was observed in the mitochondria. Till 4 h 15 min of arsenic exposure, the baseline images remained unchanged (i). After 4 h and 30 min of arsenic exposure, TMRM fluorescence was increased (iib) indicating hyperpolarization of the mitochondria, whereas there was no significant change of green fluorescence of calcein as shown in the image (iia). After 4 h and 45 min, calcein began to redistribute from the cytosol into the mitochondria as evident by increase distribution of green fluorescence, indicating onset of MPT (iiia) with simultaneous membrane blebbing as shown by the phase image (iiic), and mitochondria lost most of the TMRM red fluorescence (iiib). After 5 h, TMRM red fluorescence almost disappeared rather weak, and one cell lost TMRM fluorescence completely (ivb). Increase in cell membrane blebs was seen in the phase image (ivc) as well as calcein fluorescence was almost uniformly distributed (iva) indicating the completion of MPT. Scale bar (−−) is 10 μm.