Glial cell activity is maintained during prolonged inflammatory challenge in rats
We evaluated the expression of glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), ionized calcium binding adaptor protein-1 (Iba-1), and ferritin in rats after single or repeated lipopolysaccharide (LPS) treatment, which is known to induce endotoxin tolerance and glial activation. Ma...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Associação Brasileira de Divulgação Científica
2012-08-01
|
| Series: | Brazilian Journal of Medical and Biological Research |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000800014 |
| _version_ | 1819018049131380736 |
|---|---|
| author | B.C. Borges R. Rorato J Antunes-Rodrigues L.L.K. Elias |
| author_facet | B.C. Borges R. Rorato J Antunes-Rodrigues L.L.K. Elias |
| author_sort | B.C. Borges |
| collection | DOAJ |
| description | We evaluated the expression of glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), ionized calcium binding adaptor protein-1 (Iba-1), and ferritin in rats after single or repeated lipopolysaccharide (LPS) treatment, which is known to induce endotoxin tolerance and glial activation. Male Wistar rats (200-250 g) received ip injections of LPS (100 µg/kg) or saline for 6 days: 6 saline (N = 5), 5 saline + 1 LPS (N = 6) and 6 LPS (N = 6). After the sixth injection, the rats were perfused and the brains were collected for immunohistochemistry. After a single LPS dose, the number of GFAP-positive cells increased in the hypothalamic arcuate nucleus (ARC; 1 LPS: 35.6 ± 1.4 vs control: 23.1 ± 2.5) and hippocampus (1 LPS: 165.0 ± 3.0 vs control: 137.5 ± 2.5), and interestingly, 6 LPS injections further increased GFAP expression in these regions (ARC = 52.5 ± 4.3; hippocampus = 182.2 ± 4.1). We found a higher GS expression only in the hippocampus of the 6 LPS injections group (56.6 ± 0.8 vs 46.7 ± 1.9). Ferritin-positive cells increased similarly in the hippocampus of rats treated with a single (49.2 ± 1.7 vs 28.1 ± 1.9) or repeated (47.6 ± 1.1 vs 28.1 ± 1.9) LPS dose. Single LPS enhanced Iba-1 in the paraventricular nucleus (PVN: 92.8 ± 4.1 vs 65.2 ± 2.2) and hippocampus (99.4 ± 4.4 vs 73.8 ± 2.1), but had no effect in the retrochiasmatic nucleus (RCA) and ARC. Interestingly, 6 LPS increased the Iba-1 expression in these hypothalamic and hippocampal regions (RCA: 57.8 ± 4.6 vs 36.6 ± 2.2; ARC: 62.4 ± 6.0 vs 37.0 ± 2.2; PVN: 100.7 ± 4.4 vs 65.2 ± 2.2; hippocampus: 123.0 ± 3.8 vs 73.8 ± 2.1). The results suggest that repeated LPS treatment stimulates the expression of glial activation markers, protecting neuronal activity during prolonged inflammatory challenges. |
| first_indexed | 2024-12-21T03:13:14Z |
| format | Article |
| id | doaj.art-28a3f4319c3746eeb74f2b00f4d61e74 |
| institution | Directory Open Access Journal |
| issn | 0100-879X 1414-431X |
| language | English |
| last_indexed | 2024-12-21T03:13:14Z |
| publishDate | 2012-08-01 |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-28a3f4319c3746eeb74f2b00f4d61e742022-12-21T19:17:54ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X1414-431X2012-08-01458784791Glial cell activity is maintained during prolonged inflammatory challenge in ratsB.C. BorgesR. RoratoJ Antunes-RodriguesL.L.K. EliasWe evaluated the expression of glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), ionized calcium binding adaptor protein-1 (Iba-1), and ferritin in rats after single or repeated lipopolysaccharide (LPS) treatment, which is known to induce endotoxin tolerance and glial activation. Male Wistar rats (200-250 g) received ip injections of LPS (100 µg/kg) or saline for 6 days: 6 saline (N = 5), 5 saline + 1 LPS (N = 6) and 6 LPS (N = 6). After the sixth injection, the rats were perfused and the brains were collected for immunohistochemistry. After a single LPS dose, the number of GFAP-positive cells increased in the hypothalamic arcuate nucleus (ARC; 1 LPS: 35.6 ± 1.4 vs control: 23.1 ± 2.5) and hippocampus (1 LPS: 165.0 ± 3.0 vs control: 137.5 ± 2.5), and interestingly, 6 LPS injections further increased GFAP expression in these regions (ARC = 52.5 ± 4.3; hippocampus = 182.2 ± 4.1). We found a higher GS expression only in the hippocampus of the 6 LPS injections group (56.6 ± 0.8 vs 46.7 ± 1.9). Ferritin-positive cells increased similarly in the hippocampus of rats treated with a single (49.2 ± 1.7 vs 28.1 ± 1.9) or repeated (47.6 ± 1.1 vs 28.1 ± 1.9) LPS dose. Single LPS enhanced Iba-1 in the paraventricular nucleus (PVN: 92.8 ± 4.1 vs 65.2 ± 2.2) and hippocampus (99.4 ± 4.4 vs 73.8 ± 2.1), but had no effect in the retrochiasmatic nucleus (RCA) and ARC. Interestingly, 6 LPS increased the Iba-1 expression in these hypothalamic and hippocampal regions (RCA: 57.8 ± 4.6 vs 36.6 ± 2.2; ARC: 62.4 ± 6.0 vs 37.0 ± 2.2; PVN: 100.7 ± 4.4 vs 65.2 ± 2.2; hippocampus: 123.0 ± 3.8 vs 73.8 ± 2.1). The results suggest that repeated LPS treatment stimulates the expression of glial activation markers, protecting neuronal activity during prolonged inflammatory challenges.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000800014LPS toleranceAstrocytesMicrogliaGlial fibrillary acidic proteinIba-1Glutamine synthetaseFerritin |
| spellingShingle | B.C. Borges R. Rorato J Antunes-Rodrigues L.L.K. Elias Glial cell activity is maintained during prolonged inflammatory challenge in rats Brazilian Journal of Medical and Biological Research LPS tolerance Astrocytes Microglia Glial fibrillary acidic protein Iba-1 Glutamine synthetase Ferritin |
| title | Glial cell activity is maintained during prolonged inflammatory challenge in rats |
| title_full | Glial cell activity is maintained during prolonged inflammatory challenge in rats |
| title_fullStr | Glial cell activity is maintained during prolonged inflammatory challenge in rats |
| title_full_unstemmed | Glial cell activity is maintained during prolonged inflammatory challenge in rats |
| title_short | Glial cell activity is maintained during prolonged inflammatory challenge in rats |
| title_sort | glial cell activity is maintained during prolonged inflammatory challenge in rats |
| topic | LPS tolerance Astrocytes Microglia Glial fibrillary acidic protein Iba-1 Glutamine synthetase Ferritin |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000800014 |
| work_keys_str_mv | AT bcborges glialcellactivityismaintainedduringprolongedinflammatorychallengeinrats AT rrorato glialcellactivityismaintainedduringprolongedinflammatorychallengeinrats AT jantunesrodrigues glialcellactivityismaintainedduringprolongedinflammatorychallengeinrats AT llkelias glialcellactivityismaintainedduringprolongedinflammatorychallengeinrats |