| Full text | |
| Author(s): |
Florencio-Silva, Rinaldo
[1]
;
Sasso, Gisela R. S.
[2]
;
Sasso-Cerri, Estela
[3]
;
Simoes, Manuel J.
[1]
;
Cerri, Paulo S.
[3]
Total Authors: 5
|
| Affiliation: | [1] Univ Fed Sao Paulo UNIFESP, EPM, Dept Morfol & Genet, Disciplina Histol & Biol Estrutural, Sao Paulo, SP - Brazil
[2] Univ Fed Sao Paulo UNIFESP, EPM, Dept Ginecol, Sao Paulo, SP - Brazil
[3] Sao Paulo State Univ UNESP, Sch Dent, Araraquara Lab Histol & Embryol, Araraquara, SP - Brazil
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | BIOMEDICINE & PHARMACOTHERAPY; v. 98, p. 406-415, FEB 2018. |
| Web of Science Citations: | 6 |
| Abstract | |
Estrogen maintains osteocyte viability, whereas its deficiency induces osteocyte apoptosis. As autophagy is important for osteocyte viability, we hypothesized whether the anti-apoptotic effect of estrogen is related to autophagy in osteocytes. Thirty adult female rats were sham-operated (SHAM) or ovariectomized (OVX). After three weeks, twelve rats of SHAM and OVX groups were killed before treatment (basal period), whereas the remaining rats received estrogen (OVXE) or vehicle (OVX) for 45 days. Fragments of maxilla containing alveolar process of the first molars were embedded in paraffin or Araldite. Paraffin-sections were stained with hematoxylin/eosin for histomorphometry, or subjected to the silver impregnation method for morphological analysis of osteocyte cytoplasmic processes. Autophagy was analyzed by immunohistochemical detections of beclin-1, MAP-LC3 alpha and p62, whereas apoptosis was evaluated by immunohistochemical detections of cleaved caspase-3 and BAX, TUNEL (Terminal deoxynucleotidyl transferase dUTP nick end labeling) method and by ultrastructural analysis. Araldite-semithin sections were subjected to the Sudan-black method for detection of lipids. OVX-basal group showed high frequency of caspase-3-, TUNEL- and p62-positive osteocytes accompanied with low frequency of beclin-1- and MAP-LC3 alpha-positive osteocytes. At 45 days, OVXE group exhibited higher number of osteocytes, higher frequency of beclin-1- and MAP-LC3 alpha-positive osteocytes, and lower frequency of caspase-3, BAX-, TUNEL- and p62-positive osteocytes than OVX group. Significant reduction in bone area was observed in the OVX compared to OVXE and SHAM groups. The highest frequency of Sudan-Black-positive osteocytes and osteocytes with scarce cytoplasmic processes, or showing apoptotic features were mainly observed in OVX groups. Our results indicate that estrogen deficiency decreases autophagy and increases apoptosis, whereas estrogen replacement enhances osteocyte viability by inhibiting apoptosis and maintaining autophagy in alveolar process osteocytes. These results suggest that the anti-apoptotic effect of estrogen may be, at least in part, related to autophagy regulation in osteocytes. (AU) | |
| FAPESP's process: | 12/19428-8 - Evaluation of autophagy and cell death in osteocytes of alveolar bone in ovariectomized female rats treated with estrogen |
| Grantee: | Paulo Sergio Cerri |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 12/22666-8 - Cellular and molecular mechanisms during the early development of rat alveolar bone |
| Grantee: | Paulo Sergio Cerri |
| Support Opportunities: | Regular Research Grants |