Organ function, sphingolipid levels and inflammation in tunicamycin induced endoplasmic reticulum stress in male rats

Abstract

Disorders of the endoplasmic reticulum (ER) lead to cellular damage but can cause cell death if ER dysfunction is prolonged. We aimed to examine liver/kidney functions, neutral sphingomyelinase (N-SMase) activity, sphingolipid levels, cytosolic phospholipase A2 (cPLA2) and cyclooxygenase-2 (COX-2) protein expression in rats under ER stress. ER stress was induced by tunicamycin (TM) and the ER stress inhibitor taurodeoxycholic acid (TUDCA) was injected before induction of ER stress. ER stress was confirmed by increased tissue levels of GRP78. Hematological and biochemical profiles were measured by autoanalyzers while hepatic and renal injury was evaluated via microscopy and histopathological scoring. Tissue levels of C16-C24 sphingomyelins (SM), C16-C24 ceramides (CERs) and sphingosine-1-phosphate (S1P) were determined by LC-MS/MS. Tissue cPLA2 and COX-2 were measured by western blot and activity assays. Tunicamycin treatment caused kidney and liver function test abnormalities, increased hematocrit and hemoglobin levels but decreased white blood cell counts. Histopathological findings showed hepatic necroinflammation and renal tubular damage in rats treated with TM. TUDCA administration attenuated WBC abnormalities and TM- induced hepatic/renal functional impairment in ER stress, as evident by significantly restored serum ALT, AST, creatinine, and total bilirubin levels. A significant increase was observed in N-SMase activity, tissue levels of C16-C24 CERs, cPLA2 and COX-2 expression in liver and kidney tissue under ER stress. TUDCA administration decreased tissue CER levels, cPLA2 and COX-2 expression as well as prostaglandin E2 (PGE2) formation. These results signify that ER stress causes hepatic and renal toxicity as well as CER-induced PGE2 formation in liver and kidney.

Inflammatory signal transduction pathways induced by prilocaine toxicity in cultured ARPE‐19 cells

“…Western blot analysis was performed as described previously. [ 28 ] Rabbit polyclonal anti–NF‐κB p65 (1:1000, #ab16502, Abcam), rabbit polyclonal antiphospho NF‐κB‐p65 (Ser 536) (1:1000, #3031, Cell Signaling Technology), rabbit polyclonal anti‐ phospho‐AKT (Ser 473) (1:500, #649001, BioLegend) and antiactin (1:1000, #AANO1, Cytoskeleton Inc.) were used as primary antibodies with an incubation period of 1 h at room temperature. Horseradish peroxidase–conjugated goat anti‐rabbit IgG (1:10,000 dilution; Zymed Laboratories) was used as the secondary antibody.…”

Effects of aurantiamide on a rat model of renovascular arterial hypertension

“…Supernatants were stored at -80 °C until analyzed. Western blot analysis was performed essentially as described in detail previously [ 8 ]. Rabbit polyclonal anti-eNOS (1:200 dilution, #MBS8242404, MyBiosource Inc., San Diego, CA, USA) and anti-actin (1:1000, #AANO1, Cytoskeleton Inc. Denver, CO, USA) for 1 h at room temperature.…”

A Rheostat of Ceramide and Sphingosine-1-Phosphate as a Determinant of Oxidative Stress-Mediated Kidney Injury

“…Transfection of SphK1 into RTCs overexpressing CerS1 rendered the cells more resistant to cisplatin toxicity [ 108 ], suggesting that a rheostat of ceramide-S1P can determine sensitivity to cisplatin. Tunicamycins, antibiotics which induce ROS production and ER stress [ 271 ], increased the ceramide/S1P ratio, leading to necrosis in the kidney [ 272 ]. In addition, radiation-induced ceramide production caused apoptosis in ECs, whereas the treatment with S1P prevented these events by decreasing the ratio of ceramide/S1P [ 68 ].…”