Investigating the Effect of Tumor Necrosis Factor Alpha on Placenta and Gene Related Bone Formation of Newborn Mice
Author(s): Farad Mortezazadeh, Fatemeh Fadaei Fathabady, Mohsen Norouzian, Seyed Noureddin Nematollahi-Mahani, Abdollah Amini, Saeideh Jafarinejad-Farsangi, Seyede Elmira Yazdi Rouholamini, Abdolreza Babaee, Mohsen Basiri
Background: The cytokine tumor necrosis factor α (TNF-α) is known to play an important role in modulation of bone cell function, regulation and differentiation. Its effects depend on dosage level and long of time exposure. Until now, there is little information about the effects of TNF-α on development of bone tissue and bone formation during pregnancy and early postnatal periods. Therefore, this study aimed to investigate the effects of TNF-α on bone formation in mice.
Methods: This study was experimentally conducted on 42 female NMARI pregnant mice. Pregnant mice were randomly divided into seven groups (6 mice in each groups) including: experimental 1 (TNF-α injection (100 ng) in 7th-9th pregnancy days), experimental 2 (TNF-α injection (10 ng) in 7th-9th pregnancy days), experimental 3 (TNF-α injection (10 ng) during pregnancy) and experimental 4 (TNF-α injection (100 ng) during pregnancy), control (without injection), vehicle 1 (PBS injection in 7th-9th pregnancy days), vehicle 2 (PBS injection during pregnancy). After breeding, the pops were collected, weighted and their number and length (crown-heel length, crown-rump length) were measured, then they were prepared for histological and gene expression study. The collected data were normalized, and analyzed through one-way ANOVA test, and presented as Mean+SEM. Herein the significance were considered as p<0.05.
Results: The histologic study of the placenta showed a significant increase in inflammatory cells such as macrophages indicating the inflammation in placenta tissue of experimental groups P<0.05. There was no significant difference in length, weight and numbers of newborn mice among groups (P>0.05). The qReal time PCR results showed that the expression of osteoblast and bone forming related genes (RNUX2 and Osteocalcin) were significantly lower in experimental groups in comparison to control group (P value=0.02 for RUNX2 and (P value=0.02 for Osteocalcin).
Conclusions: TNF-α injection during pregnancy as long time or as single dose cause a dramatic alteration on bone formation of newborn mice.