The role of microRNAs (miRNAs) during mouse early development, especially in endoderm germ layer formation, is largely unknown. Here, via miRNA profiling during endoderm differentiation, we discovered that miR-124a negatively regulates endoderm lineage commitment in mouse embryonic stem cells (mESCs). To further investigate the functional role of miR-124a in early stages of differentiation, transfection of embryoid bodies with miR-124a mimic was performed. We showed that overexpression of miR-124a inhibits endoderm differentiation in vitro through targeting the 3'-untranslated region (UTR) of Sox17 and Gata6, revealing the existence of interplay between miR-124a and the Sox17/Gata6 transcription factors in hepato-specific gene regulation. In addition, we presented a feasible in vivo system that utilizes teratoma and gene expression profiling from microarray to quantitatively evaluate the functional role of miRNA in lineage specification. We demonstrated that ectopic expression of miR-124a in teratomas by intratumor delivery of miR-124a mimic and Atelocollagen, significantly suppressed endoderm and mesoderm lineage differentiation while augmenting the differentiation into ectoderm lineage. Collectively, our findings suggest that miR-124a plays a significant role in mESCs lineage commitment.
Mature cystic teratoma is the commonest ovarian germ cell tumour which accounts for 70% of all benign ovarian neoplasms in the reproductive age groups. Being a pluripotent germ cell tumour, mature cystic teratoma has at least two out of three mature embryonic germ cell components: ectoderm, mesoderm and endoderm. The presence of multiple cystic spaces within the tumour wall, also known as pneumatosis cystoides-like appearance is rarely described but a characteristic feature in cystic teratoma of the ovary. Currently, there is little information concerning the mechanism of its formation. Herein, we described an unusual case of ovarian mature cystic teratoma in a 31-year-old pregnant female with multiple sieve-like areas resembling pneumatosis cystoides of the intestine. Macroscopic and histological examination of the ovary revealed features diagnostic of mature cystic teratoma. Intriguingly, multiple cystic spaces of variable sizes were found within the cyst wall histologically. They were lined partially or completely by foamy histiocytes and foreign body type multinucleated giant cells, exhibiting strong CD68 immunoreactivity. Vascular endothelial markers (CD31 and CD34) and epithelial marker (cytokeratin AE1/AE3) were negative. A diagnosis of mature cystic teratoma with pneumatosis cystoides-like feature was rendered. The patient was discharged well with no signs and symptoms of early labour. The etiopathogenesis of this intriguing histological feature is briefly discussed in this article.
Hydra actinoporin-like toxin 1 (HALT-1) was previously shown to cause cytolysis and haemolysis in a number of human cells and has similar functional properties to the actinoporins equinatoxin and sticholysin. In addition to HALT-1, five other HALTs (HALTs 2, 3, 4, 6 and 7) were also isolated from Hydra magnipapillata and expressed as recombinant proteins in this study. We demonstrated that recombinant HALTs have cytolytic activity on HeLa cells but each exhibited a different range of toxicity. All six recombinant HALTs bound to sulfatide, while rHALT-1 and rHALT-3 bound to two additional sphingolipids, lysophosphatidic acid and sphingosine-1-phosphate as indicated by the protein-lipid overlay assay. When either tryptophan133 or tyrosine129 of HALT-1 was mutated, the mutant protein lost binding to sulfatide, lysophosphatidic acid and sphingosine-1-phosphate. As further verification of HALTs' binding to sulfatide, we performed ELISA for each HALT. To determine the cell-type specific gene expression of seven HALTs in Hydra, we searched for individual HALT expression in the single-cell RNA-seq data set of Single Cell Portal. The results showed that HALT-1, 4 and 7 were expressed in differentiating stenoteles. HALT-1 and HALT-6 were expressed in the female germline during oogenesis. HALT-2 was strongly expressed in the gland and mucous cells in the endoderm. Information on HALT-3 and HALT-5 could not be found in the single-cell data set. Our findings show that subfunctionalisation of gene expression following duplication enabled HALTs to become specialized in various cell types of the interstitial cell lineage.