Human and rat tissues were sectioned at 5 μm for either hematoxylin and eosin staining or immunohistochemical staining. Activation of UPR was assessed by antibody reactivity to activating transcription factor 6 (ATF6, Imgenex-273 1:100) and C/EBP homologous protein (CHOP, Abcam Ab11419 1:100). Apoptotic cells were identified by immunoreactivity to cleaved caspase-3 antibody (Abcam Ab47131 1:200). The cleaved caspase-3-positive cells were counted and divided by the total number of cells in three randomly chosen high-power field (×400) for each section from each of three animals per group. The mean percentage of caspase-3+ cells for each animal was then obtained by averaging the results of the countings. Macrophages were identified by staining with antibodies against CD68 (AbBiotec 250594 1:200). Secondary antibodies conjugated to fluorescent dyes (Invitrogen), or biotin combined with immunoperoxidase/avidin-biotin, were as per the manufacturer protocol (Vectastain ABC kit, Vector Labs), and either hematoxylin or Nuclear Fast Red (Vector Labs) was used as a counterstain. Avidin/biotin blocking kits (Vector Labs) were used to block endogenous enzyme activity. Antibody isotype negative controls were included with each sample group. Images were acquired at room temperature using a Zeiss Axiovert S100 fitted with Zeiss 20×0.4 numerical aperture (n.a.) and 10×0.3 n.a. objectives and Axiocam camera. Acquisition of images was by Axiovision 4.6 software (Zeiss).