| First Author | Malik G | Year | 2019 |
| Journal | J Cell Mol Med | Volume | 23 |
| Issue | 5 | Pages | 3336-3344 |
| PubMed ID | 30761739 | Mgi Jnum | J:294147 |
| Mgi Id | MGI:6454658 | Doi | 10.1111/jcmm.14224 |
| Citation | Malik G, et al. (2019) PECAM-1 modulates liver damage induced by synergistic effects of TNF-alpha and irradiation. J Cell Mol Med 23(5):3336-3344 |
| abstractText | The mechanisms of radiation-induced liver damage are poorly understood. We investigated if tumour necrosis factor (TNF)-alpha acts synergistically with irradiation, and how its activity is influenced by platelet endothelial cell adhesion molecule-1 (PECAM-1). We studied murine models of selective single-dose (25 Gy) liver irradiation with and without TNF-alpha application (2 mug/mouse; i.p.). In serum of wild-type (wt)-mice, irradiation induced a mild increase in hepatic damage marker aspartate aminotransferase (AST) in comparison to sham-irradiated controls. AST levels further increased in mice treated with both irradiation and TNF-alpha. Accordingly, elevated numbers of leucocytes and increased expression of the macrophage marker CD68 were observed in the liver of these mice. In parallel to hepatic damage, a consecutive decrease in expression of hepatic PECAM-1 was found in mice that received radiation or TNF-alpha treatment alone. The combination of radiation and TNF-alpha induced an additional significant decline of PECAM-1. Furthermore, increased expression of hepatic lipocalin-2 (LCN-2), a hepatoprotective protein, was detected at mRNA and protein levels after irradiation or TNF-alpha treatment alone and the combination of both. Signal transducer and activator of transcription-3 (STAT-3) seems to be involved in the signalling cascade. To study the involvement of PECAM-1 in hepatic damage more deeply, the liver of both wt- and PECAM-1-knock-out-mice were selectively irradiated (25 Gy). Thereby, ko-mice showed higher liver damage as revealed by elevated AST levels, but also increased hepatoprotective LCN-2 expression. Our studies show that TNF-alpha has a pivotal role in radiation-induced hepatic damage. It acts in concert with irradiation and its activity is modulated by PECAM-1, which mediates pro- and anti-inflammatory signalling. |
