Rabbit Anti-Human SMPD2 Polyclonal antibody

Ursodeoxycholic acid (UDCA) is used to treat liver diseases and demonstrates cardioprotective effects. Accumulation of the plasma membrane sphingolipid sphingomyelin in the heart can lead to atherosclerosis and coronary artery disease. Sphingomyelinases (SMases) break down sphingomyelin, producing ceramide, and inhibition of SMases activity can promote cell survival. We hypothesized that UDCA regulates activation of ERK and Akt survival signaling pathways and SMases in protecting cardiac cells against hypoxia. Neonatal cardiomyocytes were isolated from 0-to 2-day-old Sprague Dawley rats, and given 100 mu M CoCl2, 150 mu M H2O2, or placed in a hypoxia chamber for 24 h. The ameliorative effects of 100-mu M UDCA treatment for 12 h were then assessed using MTS, QuantiGene Plex (for Smpd1 and Smpd2), and SMase assays, beating rate assessment, and western blotting (for ERK and Akt). Data were analyzed by the paired Student t-tests and one-way analyses of variance. Cell viability decreased significantly after H2O2 (85%), CoCl2 (50%), and hypoxia chamber (52%) treatments compared to the untreated control (100%). UDCA significantly counteracted the effects of chamber-and CoCl2--induced hypoxia on viability and beating rate. However, no significant differences were observed in acid SMase gene and protein expression between the untreated, CoCl2, and UDCA-CoCl2 groups. In contrast, neutral SMase gene and protein expression did significantly differ between the latter two groups. ERK and Akt phosphorylation was higher in hypoxic cardiomyocytes treated with UDCA than those given CoCl2 alone. In conclusion, UDCA regulates the activation of survival signaling proteins and SMases in neonatal rat cardiomyocytes during hypoxia.

Ultrasound can be used to target endothelial cells in cancer therapy where the destruction of vasculature leads to tumor cell death. Here, we demonstrate ultrasound bioeffects in which the levels of genes in endothelial cells can be significantly altered by ultrasound-stimulated microbubble exposure. These were compared with established effects of radiation on endothelial cells at a gene level. Human-endothelial cells were exposed to ultrasound and microbubbles, radiation or combinations of ultrasound, microbubbles and radiation. Gene expression analyses revealed an up-regulation of genes known to be involved in apoptosis and ceramide-induced apoptotic pathways, including SMPD2, UGT8, COX6B1, Caspase 9 and MAP2K1 with ultrasound-stimulated microbubble exposure but not SMPD1. This was supported by immunohistochemistry and morphologic changes examined with cell microscopy, which showed changes in SMPD1 gene product in cells with microbubble exposure. This supports the hypothesis that ultrasound-stimulated microbubbles can induce significant bioeffect-related changes in gene expression and can affect ceramide signaling pathways in endothelial cells, leading to apoptosis. (E-mail: Gregory.Czarnota@sunnybrook.ca) Crown Copyright (C) 2012 Published by Elsevier Inc. on behalf of World Federation for Ultrasound in Medicine & Biology.