Abstract Bone infection or osteomyelitis is usually a complication of inflammation-related traumatic bone injury. Selenium has been shown to have potential cytoprotective effects and the ability to reduce oxidative stress and apoptotic events in osteomyelitis, but the exact mechanism remains unclear. Here, we used LPS-induced apoptotic MC3T3-E1 cells and aimed to confirm selenium's protective effect on cell apoptosis as well as to investigate the underlying mechanisms of this role. Our investigation confirmed selenium-mediated inhibition of LPS-induced cell apoptosis and ROS accumulation in MC3T3-E1 cells. Upon selenium treatment, the bcl-2 levels were upregulated, while the levels of Bax and cyto-C were down-regulated. Furthermore, these effects were accompanied by the suppression of miR-155 and the phosphorylation of protein kinase B (Akt). A more in-depth study demonstrated that LY294002 (a specific inhibitor of PI3K), abolished the selenium-mediated cytoprotective effect of MC3T3-E1 cells against LPS-induced injury and down-regulation of miR-155. In general, these results demonstrated that selenium exerts a cytoprotective effect by attenuating cell apoptosis and oxidative damage via a PI3K/Akt/miR-155-dependent mechanism.

Resumo Fundamentos: O modelo de hipertrofia cardíaca (HC) para ratos foi amplamente utilizado, proporcionando assim uma base de pesquisa efetiva para a exploração de HC. Objetivo: pesquisar os efeitos do modelamento de HC sob constrição da aorta abdominal (CAA) usando diferentes agulhas e pesos em ratos. Métodos: foram utilizadas quatro agulhas com diâmetros externos diferentes (0,35, 0,40, 0,45 e 0,50 mm) para CAA. Foram selecionados 150 ratos C57BL / 6 machos de acordo com o peso corporal (PC) e divididos em 3 níveis de peso: 18 g, 22 g e 26g (n = 50 em cada grupo). Todos os níveis de peso foram divididos em 5 grupos: um grupo sham (n = 10) e 4 grupos CAA usando 4 intensidades de ligadura (n = 10 por grupo). Após a cirurgia, foram registradas as taxas de sobrevivência, foi realizada ecocardiografia, os corações foram dissecados e utilizados para detecção histológica, e os dados foram analisados estatisticamente, p < 0,05 foi considerado estatisticamente significante. Resultados: Todos os ratos morreram nos seguintes grupos de CAA: 18 g/0,35 mm, 22 g/0,35 mm, 26 g/0,35 mm, 22 g/0,40 mm e 26 g/0,40 mm. Todos os ratos com CAA, aqueles ligados com uma agulha de 0,50 mm, e aqueles que sofreram operação sham sobreviveram. Ocorreram diferentes taxas de mortalidade nos seguintes grupos de CAA: 18 g/0,40 mm, 18 g/0,45 mm, 18 g/0,50 mm, 22 g/45 mm, 22 g/0,50 mm, 26 g/0,45 mm e 26 g/0,50 mm. As proporções de peso do coração/peso corporal (5,39 ± 0,85, 6,41 ± 0,68, 4,67 ± 0,37, 5,22 ± 0,42, 4,23 ± 0,28, 5,41 ± 0,14 e 4,02 ± 0,13) aumentaram significativamente em comparação com os grupos sham para ratos com os mesmos níveis de peso. Conclusão: uma agulha de 0,45mm levou a HC mais óbvia do que as agulhas de 0,40 mm e 0,50mm e causou HC extraordinária em ratos de 18 g.

Abstract Background: The cardiac hypertrophy (CH) model for mice has been widely used, thereby providing an effective research foundation for CH exploration. Objective: To research the effects of CH modeling under abdominal aortic constriction (AAC) using different needles and weights in mice. Methods: Four needles with different external diameters (0.35, 0.40, 0.45, and 0.50 mm) were used for AAC. 150 male C57BL/6 mice were selected according to body weight (BW) and divided into 3 weight levels: 18 g, 22 g, and 26 g (n = 50 in each group). All weight levels were divided into 5 groups: a sham group (n = 10) and 4 AAC groups using 4 ligation intensities (n = 10 per group). After surgery, survival rates were recorded, echocardiography was performed, hearts were dissected and used for histological detection, and data were statistically analyzed, P < 0.05 was considered statistically significant. Results: All mice died in the following AAC groups: 18g/0.35 mm, 22 g/0.35 mm, 26 g/0.35 mm, 22 g/0.40 mm, and 26 g/0.40 mm. All mice with AAC, those ligated with a 0.50-mm needle, and those that underwent sham operation survived. Different death rates occurred in the following AAC groups: 18 g/0.40 mm, 18 g/0.45 mm, 18 g/0.50 mm, 22 g/45 mm, 22 g/0.50 mm, 26 g/0.45 mm, and 26 g/0.50 mm. The heart weight/body weight ratios (5.39 ± 0.85, 6.41 ± 0.68, 4.67 ± 0.37, 5.22 ± 0.42, 4.23 ± 0.28, 5.41 ± 0.14, and 4.02 ± 0.13) were significantly increased compared with those of the sham groups for mice with the same weight levels. Conclusion: A 0.45-mm needle led to more obvious CH than did 0.40-mm and 0.50-mm needles and caused extraordinary CH in 18-g mice.