Introduction Approximately 50% of cases with recurrent spontaneous abortion (RSA) have unexplained etiology. Aberrant expression of transmembrane and ubiquitin-like domain containing 1 (TMUB1) is closely related to a series of diseases, including RSA. However, the function and underlying mechanism of TMUB1 in the occurrence of RSA has not been described. Methods TMUB1 expression was detected in the placental villous tissues of 30 women with normal miscarriages and 12 women with RSA. The pregnant mice were injected intraperitoneally with lipopolysaccharide (LPS) to induce abortion. Human chorionic trophoblast cells were treated with LPS. Pathological analysis of placental tissues was performed by hematoxylin and eosin staining. Results TMUB1 was highly expressed in the placental villous tissues of RSA patients compared to the patients who underwent induced abortions. After LPS administration, the mice exhibited high embryo absorption and pathological alterations, as well as presented an increase in inflammation and apoptosis (the etiology of RSA induction) in placental tissues. Moreover, the upregulated expression of TMUB1 was also found in placental tissues of LPS-induced mice, and further investigation showed that TMUB1 deficiency blocked embryo loss as well as inhibited apoptotic rate and inflammation after LPS activation. Furthermore, we found that the loss of TMUB1 suppressed the phosphorylation of IkappaB kinase (IKK) α/β and attenuated cytoplasmic-nuclear translocation of nuclear factor-κB (NF-κB) p65 in LPS-induced cells. Conclusion Our results indicate that TMUB1 may involve in the modulation of apoptosis and NF-κB pathway-mediated inflammation in RSA. Therefore, TMUB1 may develop as a potential biomarker for RSA treatment.
Recurrent spontaneous abortion (RSA) brings tremendous difficulties to clinical treatment and prognosis. Pre-B-cell leukemia homeobox 1 (PBX1), as a functional transcription factor, involves in the regulation of cell apoptosis and proliferation. However, the underlying mechanism of PBX1 in RSA treatment has not been explored. We established a lipopolysaccharide (LPS)-induced abortion model and detected PBX1 expression with real-time PCR, western blot and immunohistochemistry. The PBX1-overexpressed adenovirus (AV-oePBX1) was infected into trophoblast cells treated with LPS to define the function of PBX1 on cell apoptosis, inflammation and NF-κB pathway. A luciferase reporter assay was conducted to validate the transcription regulation of PBX1 on transmembrane and ubiquitin like domain containing 1 (TMUB1). Compared to women with normal abortion, PBX1 was downregulated in the placental villous tissues of RSA patients. The placental tissues of LPS-treated mice also manifested notably reduction of PBX1 at mRNA and protein levels. PBX1 overexpression alleviated inflammation and apoptosis of trophoblast cells. Substantially, PBX1 was negatively correlated with TMUB1, which was highly expressed in RSA patients and LPS-treated mice. Moreover, PBX1 bound to TMUB1 promoter and inhibited its transcription. Interestingly, exogenous TMUB1 abolished the effects of PBX1 on apoptosis, inflammation, and NF-κB signal pathway. In total, PBX1 attenuated cell apoptosis and inflammation, and suppressed NF‐κB signal pathway induced by LPS through downregulating TMUB1 transcription. Therefore, PBX1 may be developed as a novel target for clinical treatment of RSA.
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