Journal of Biomedical Science

We investigated the potency of exogenous bone marrow mesenchymal stem cells (MSCs) to engraft into irradiated intestine, as well as these cells’ effects on radiation-induced enteric injury. MSCs from β-Gal-transgenic mice were transplanted into C57BL/6J recipient mice that received abdominal irradiation (13 Gy). At different time points, recipient intestines were examined for the engraftment of donor-derived cells by immunofluorescence analysis. Additionally, the expression status of chemokines induced by radiation injury was analyzed in the irradiated intestine. Next, MSCs were transduced with an adenoviral vector encoding a certain chemokine receptor gene in order to promote the engraftment rate via chemotaxis. The intestinal permeability and histomorphological alterations were measured to evaluate the therapeutic effect of MSC transplantation. The results demonstrated that infused MSCs possessed the potency to engraft into irradiated enteric mucosa, but the engraftment rate was too low to produce a therapeutic effect. The expression of stromal cell-derived factor-1 (SDF-1) was up-regulated in irradiated intestine. MSCs genetically modified by CXCR4 (the receptor for SDF-1) engrafted into irradiated intestine at a significantly elevated level and ameliorated the intestinal permeability and histopathological damage.

Extracellular vesicle (EV)-mediated intercellular communication acts as a critical culprit in cancer development. The selective packaging of oncogenic molecules renders tumor-derived EVs capable of altering the tumor microenvironment and thereby modulating cancer developments that may contribute to drug resistance and cancer recurrence. Moreover, the molecular and functional characteristics of cancer through its development and posttreatment evolve over time. Tumor-derived EVs are profoundly involved in this process and can, therefore, provide valuable real-time information to reflect dynamic changes occurring within the body. Because they bear unique molecular profiles or signatures, tumor-derived EVs have been highlighted as valuable diagnostic and predictive biomarkers as well as novel therapeutic targets. In addition, the use of an advanced EV-based drug delivery system for cancer therapeutics has recently been emphasized in both basic and clinical studies. In this review, we highlight comprehensive aspects of tumor-derived EVs in oncogenic processes and their potential clinical applications.

With the advances in deep sequencing-based transcriptome profiling technology, it is now known that human genome is transcribed more pervasively than previously thought. Up to 90% of the human DNA is transcribed, and a large proportion of the human genome is transcribed as long noncoding RNAs (lncRNAs), a heterogenous group of non-coding transcripts longer than 200 nucleotides. Emerging evidence suggests that lncRNAs are functional and contribute to the complex regulatory networks involved in cardiovascular development and diseases. In this article, we will review recent evidence on the roles of lncRNAs in the biological processes of cardiovascular development and disorders. The potential applications of lncRNAs as biomarkers and targets for therapeutics are also discussed.

Translation efficiency is often regulated in part by 5′-untranslated region (5′UTR). Sequence analysis of an evolutionarily conserved stress-responsive protein, Drosophila Peroxiredoxin I (dPrx I), found the transcript to have two alternative 5′UTRs that lead to an identical coding sequence: namely Ia and Ib. Although both isoforms coexisted in Drosophila cells, the Ia isoform appeared to be dominant. Furthermore, reporter assay found that Ia enhanced translation in steady-state cells while Ib increased translation in cells under oxidative stress. Together, our data suggest that the two alternative 5′UTRs of dPrx I may be involved in a translational regulatory mechanism that responds to cellular oxidative stress.