Localization and differential expression of the Krüppel-associated box zinc finger proteins 1 and 54 in early mouse development

ZFP1 is a biomarker related to poor prognosis and immunity in gastric cancer

We aimed to determine the prognostic significance of ZFP1 in gastric cancer (GC), its role in the immune microenvironment, and its potential as a therapeutic target using data from The Cancer Genome Atlas (TCGA) database. ZFP1 overexpression was closely associated with tumour T stage and histological grade. Patients with GC and high ZFP1 expression had poor outcomes. Lower ZFP1 expression was associated with longer symptom-free intervals and disease-specific survival. Subgroup analyses of T3 and T4, N0, N1, and M0 patients showed that overall survival (OS), disease-specific survival, and progression-free interval (PFI) were worse in those with high ZFP1 expression. ZFP1 expression in GC was moderately to strongly positively correlated with the infiltration levels of effector central memory T cells and T helper cells and negatively correlated with Th17 cells and NK CD56bright cells. The lncRNA-miRNA-ZFP1 axis was predicted using a public database. CCK8, colony formation, and wound healing assays were conducted to investigate whether ZFP1 promoted the proliferation and migration of GC cells. Our study suggests that ZFP1 plays a key role in the prognosis, immune response, and progression of GC and is a significant factor in the diagnosis and treatment of this disease.

Maternally contributed Nlrp9b expressed in human and mouse ovarian follicles contributes to early murine preimplantation development

PURPOSE

The aim of the study is to investigate presence and role of the gene encoding the maternally contributed nucleotide-binding oligomerization domain (NOD)-like receptors with a pyrin domain (PYD)-containing protein 9 (NLRP9) in human and mouse ovaries, respectively, and in preimplantation mouse embryo development by knocking down Nlrp9b.

METHODS

Expression levels of NLRP9 mRNA in human follicles were extracted from RNA sequencing data from previous studies. In this study, we performed a qPCR analysis of Nlpr9b mRNA in mouse oocytes and found it present. Intracellular ovarian distribution of NLRP9B protein was accomplished using immunohistochemistry. The distribution of NLRP9B was explored using a reporter gene approach, fusing NLRP9B to green fluorescent protein and microinjection of in vitro-generated mRNA. Nlrp9b mRNA function was knocked down by microinjection of short interference (si) RNA targeting Nlrp9b, into mouse pronuclear zygotes. Knockdown of the Nlrp9b mRNA transcript was confirmed by qPCR.

RESULT

We found that the human NLRP9 gene and its corresponding protein are highly expressed in human primordial and primary follicles. The NLRP9B protein is localized to the cytoplasm in the blastomeres of a 2-cell embryo in mice. SiRNA-mediated knockdown of Nlrp9b caused rapid elimination of endogenous Nlrp9b mRNA and premature embryo arrest at the 2- to 4-cell stages compared with that of the siRNA-scrambled control group.

CONCLUSIONS

These results suggest that mouse Nlrp9b, as a maternal effect gene, could contribute to mouse preimplantation embryo development. It remains to investigate whether NLRP9 have a crucial role in human preimplantation embryo and infertility.

Maternally Contributed Folate Receptor 1 Is Expressed in Ovarian Follicles and Contributes to Preimplantation Development

Folates have been shown to play a crucial role for proper development of the embryo as folate deficiency has been associated with reduced developmental capacity such as increased risk of fetal neural tube defects and spontanous abortion. Transcripts encoding the reduced folate carrier RFC1 (SLC19A1 protein) and the high-affinity folate receptor FOLR1 are expressed in oocytes and preimplantation embryos, respectively. In this study, we observed maternally contributed FOLR1 protein during mouse and human ovarian follicle development, and 2-cell mouse embryos. In mice, FOLR1 was highly enriched in oocytes from primary, secondary and tertiary follicles, and in the surrounding granulosa cells. Interestingly, during human follicle development, we noted a high and specific presence of FOLR1 in oocytes from primary and intermediate follicles, but not in the granulosa cells. The distribution of FOLR1 in follicles was noted as membrane-enriched but also seen in the cytoplasm in oocytes and granulosa cells. In 2-cell embryos, FOLR1-eGFP fusion protein was detected as cytoplasmic and membrane-associated dense structures, resembling the distribution pattern observed in ovarian follicle development. Knock-down of Folr1 mRNA function was accomplished by microinjection of short interference (si)RNA targeting Folr1, into mouse pronuclear zygotes. This revealed a reduced capacity of Folr1 siRNA-treated embryos to develop to blastocyst compared to the siRNA-scrambled control group, indicating that maternally contributed protein and zygotic transcripts sustain embryonic development combined. In summary, maternally contributed FOLR1 protein appears to maintain ovarian functions, and contribute to preimplantation development combined with embryonically synthesized FOLR1.

Stella modulates transcriptional and endogenous retrovirus programs during maternal-to-zygotic transition

The maternal-to-zygotic transition (MZT) marks the period when the embryonic genome is activated and acquires control of development. Maternally inherited factors play a key role in this critical developmental process, which occurs at the 2-cell stage in mice. We investigated the function of the maternally inherited factor Stella (encoded by Dppa3) using single-cell/embryo approaches. We show that loss of maternal Stella results in widespread transcriptional mis-regulation and a partial failure of MZT. Strikingly, activation of endogenous retroviruses (ERVs) is significantly impaired in Stella maternal/zygotic knockout embryos, which in turn leads to a failure to upregulate chimeric transcripts. Amongst ERVs, MuERV-L activation is particularly affected by the absence of Stella, and direct in vivo knockdown of MuERV-L impacts the developmental potential of the embryo. We propose that Stella is involved in ensuring activation of ERVs, which themselves play a potentially key role during early development, either directly or through influencing embryonic gene expression.