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Runx2 is a master transcription factor for chondrocyte and osteoblast differentiation and bone formation. However expression of Runx2 (by RT-PCR), has been reported in non-skeletal tissues such as breast, T cells and testis. To better define Runx2 activity in non-skeletal tissues, we examined transgenic (Tg) mice expressing LacZ gene under control of 3.0 kb (3 Kb Tg) or 1.0 kb (1 Kb Tg) of the Runx2 distal (P1) promoter, Runx2 LacZ knock-in (Runx2 +/LacZ ) and Runx2/P1 LacZ knock-in (Runx2/P +/LacZ ). In the Runx2 3 Kb Tg mouse, β-galactosidase (β-gal) expression appeared in various non-skeletal tissues including testis, skin, adrenal gland and brain. β-gal expression from both 3 Kb and 1 Kb Tg, reflecting activity of the Runx2 promoter, was readily detectable in seminiferous tubules of the testis and the epididymis. At the single cell level, β-gal was detected in spermatids and mature sperms not in sertoli or Leydig cells. We also detected a positive signal from the Runx2 +/LacZ and Runx2/P1 +/LacZ mice. Indeed, Runx2 expression was observed in isolated mature sperms, which was confirmed by RT-PCR and western blot analysis. Runx2, however, was not related to sex determination and sperm motility. Runx2 mediated β-gal activity is also found robustly in the hippocampus and frontal lobe of the brain in Runx2 +/LacZ . Collectively, these results indicate that Runx2 is expressed in several non-skeletal tissues particularly sperms of testis and hippocampus of brain. It suggests that Runx2 may play an important role in male reproductive organ testis and brain.

Hepatitis delta virus (HDV) infection causes fulminant hepatitis and liver cirrhosis. To elucidate the molecular mechanism of HDV pathogenesis, we examined the effects of HDV viral proteins, the small hepatitis delta antigen (SHDAg) and the large hepatitis delta antigen (LHDAg), on NF-kappaB signaling pathway. In this study, we demonstrated that TNF-alpha-induced NF-kappaB transcriptional activation was increased by LHDAg but not by SHDAg in both HEK293 and Huh7 cells. Furthermore, LHDAg promoted TRAF2-induced NF-kappaB activation. Using coimmunoprecipitation assays, we demonstrated that both SHDAg and LHDAg interacted with TRAF2 protein. We showed that isoprenylation of LHDAg was not required for the increase of NF-kappaB activity. We further showed that only LHDAg but not SHDAg increased the TNF-alpha-mediated nuclear translocation of p65. This was accomplished by activation of IkappaBalpha degradation by LHDAg. Finally, we demonstrated that LHDAg augmented the COX-2 expression level in Huh7 cells. These data suggest that LHDAg modulates NF-kappaB signaling pathway and may contribute to HDV pathogenesis.

Purpose To compare the clinical outcomes of elective single morula embryo transfer (eSMET) versus elective single blastocyst embryo transfer (eSBET) in selected patients. Methods This study was a retrospective study which analyzed for 271 cycles in women under 37 years of age who are undergoing their first or second trial of in vitro fertilization-embryo transfer (IVF-ET) from January 2008 to December 2009. The eSMET was performed on day 4 (n0130) and the eSBET was conducted on day 5 (n0141). Results The clinical pregnancy rate (51.5% vs. 51.8%, p0 0.97), implantation rate (52.3% vs. 52.5%, p00.98), and live birth rate (39.2% vs. 44.7%, p00.36) were similar in the eSMET and eSBET groups, respectively. The miscarriage rate of the eSMET group (23.9%) was slightly higher than that of the eSBET group (13.7%) (p00.12), without reaching statistical significance. There was only one case of monozygotic twin pregnancy in each group. ConclusionsThe clinical outcomes of day 4 eSMET were comparable to those of day 5 eSBET. Therefore, day 4 eSMET is a viable option or an alternative to day 5 eSBET, with no difference in success rates.

The essential osteoblast-related transcription factor Runx2 and the female steroid hormone estrogen are known to play pivotal roles in bone homeostasis; however, the functional interaction between Runx2-and estrogenmediated signaling in skeletal tissues is minimally understood. Here we provide evidence that aromatase (CYP19), a rate-limiting enzyme responsible for estrogen biosynthesis in mammals, is transcriptionally regulated by Runx2. Consistent with the presence of multiple Runx2 binding sites, the binding of Runx2 to the aromatase promoter was demonstrated in vitro and confirmed in vivo by chromatin immunoprecipitation assays. The bone-specific aromatase promoter is activated by Runx2, and endogenous aromatase gene expression is upregulated by Runx2 overexpression, establishing the aromatase gene as a target of Runx2. The biological significance of the Runx2 transcriptional control of the aromatase gene is reflected by the enhanced estrogen biosynthesis in response to Runx2 in cultured cells. Reduced in vivo expression of skeletal aromatase gene and low bone mineral density are evident in Runx2 mutant mice. Collectively, these findings uncover a novel link between Runx2-mediated osteoblastogenic processes and the osteoblast-mediated biosynthesis of estrogen as an osteoprotective steroid hormone.