Nuclear orphan receptor TLX (Drosophila tailless homolog) is essential for the maintenance of neural stem/progenitor cell self-renewal, but its role in neuroblastoma (NB) is not well understood. Here, we show that TLX is essential for the formation of tumor spheres in three different NB cell lines, when grown in neural stem cell media. We demonstrate that the knock down of TLX in IMR-32 cells diminishes its tumor sphere-forming capacity. In tumor spheres, TLX is coexpressed with the neural progenitor markers Nestin, CD133 and Oct-4. In addition, TLX is coexpressed with the migratory neural progenitor markers CD15 and matrix metalloproteinase-2 (MMP-2) in xenografts of primary NB cells from patients. Subsequently, we show the effect of TLX on the proliferative, invasive and migratory properties of IMR-32 cells. We attribute this to the recruitment of TLX to both MMP-2 and Oct-4 gene promoters, which resulted in the respective gene activation. In support of our findings, we found that TLX expression was high in NB patient tissues when compared with normal peripheral nervous system tissues. Further, the Kaplan–Meier estimator indicated a negative correlation between TLX expression and survival in 88 NB patients. Therefore, our results point at TLX being a crucial player in progression of NB, by promoting self-renewal of NB tumor-initiating cells and altering their migratory and invasive properties.

Hypoxia promotes neural stem cell proliferation, the mechanism of which is poorly understood. Here, we have identified the nuclear orphan receptor TLX as a mediator for proliferation and pluripotency of neural progenitors upon hypoxia. We found an enhanced early protein expression of TLX under hypoxia potentiating sustained proliferation of neural progenitors. Moreover, TLX induction upon hypoxia in differentiating conditions leads to proliferation and a stem cell-like phenotype, along with coexpression of neural stem cell markers. Following hypoxia, TLX is recruited to the Oct-3/4 proximal promoter, augmenting the gene transcription and promoting progenitor proliferation and pluripotency. Knockdown of Oct-3/4 significantly reduced TLX-mediated proliferation, highlighting their interdependence in regulating the progenitor pool. Additionally, TLX synergizes with basic FGF to sustain cell viability upon hypoxia, since the knockdown of TLX along with the withdrawal of growth factor results in cell death. This can be attributed to the activation of Akt signaling pathway by TLX, the depletion of which results in reduced proliferation of progenitor cells. Cumulatively, the data presented here demonstrate a new role for TLX in neural stem cell proliferation and pluripotency upon hypoxia.The adult brain retains a reservoir of stem progenitor cells in the hippocampal "neurogenic zone" capable of proliferative activity throughout life (1). These undifferentiated precursors that retain the ability to proliferate and self-renew can give rise to both neuronal and glial lineages (2). Recent studies have emphasized the role of hypoxia in maintaining pluripotency and increased proliferation of neural stem cells (3-5).However, the molecular mechanisms underlying the increased proliferation and pluripotency of neural stem cells are yet unexplored. TLX (NR2E1), an orphan nuclear receptor expressed in vertebrate forebrains (6), is an essential regulator of adult neural stem cell self-renewal (7). TLX maintains neural stem cells in an undifferentiated and self-renewable state by complexing with histone deacetylases to repress TLX downstream target genes, such as p21 and Pten, promoting cellular proliferation (8). Furthermore, TLX is expressed in the subventricular neural stem cells in embryonic brains and plays an important role in neural development by regulating cell cycle progression of neural stem cells (9 -11). Also, TLXpositive neural stem cells play an important role in spatial learning and memory in adult brains (12).This study aimed to investigate the role of TLX in promoting neural progenitor population under differentiating conditions, considering the fact that TLX acts as a hypoxic sensor in retinal astrocytes (13), and hypoxia promotes proliferation/ dedifferentiation of progenitor cells. Our results demonstrate that TLX is responsive to hypoxia in both differentiating and proliferating conditions. The knockdown of TLX attenuates hypoxia-mediated progenitor proliferation and induces differentiation. Further investigatio...

In this study, we used proteomics and biological network analysis to evaluate the potential biological processes and components present in the identified proteins of biopsies from cutaneous leishmaniasis (CL) patients infected by Leishmania braziliensis in comparison with normal skin. We identified 59 proteins differently expressed in samples from infected and normal skin. Biological network analysis employing identified proteins showed the presence of networks that may be involved in the cell death mediated by cytotoxic T lymphocytes. After immunohistochemical analyses, the expression of caspase-9, caspase-3, and granzyme B was validated in the tissue and positively correlated with the lesion size in CL patients. In conclusion, this work identified differentially expressed proteins in the inflammatory site of CL, revealed enhanced expression of caspase-9, and highlighted mechanisms associated with the progression of tissue damage observed in lesions.

Reproductive processes in domestic pigs have been studied extensively. Pigs are one of the main sources of meat for human consumption and are an established model for investigations into mammalian, including human, reproductive physiology. Studies of the uterus during early pregnancy will lead to a better understanding of mechanisms governing pregnancy. Proteomics provides the possibility to explore endometrial functions in an unbiased way. The aim of the study was to compare endometrium harvested from Days 12-13 and 15-16 of pregnancy with the corresponding days of the oestrous cycle. We identified endometrial proteins that are unique to the early stages of pregnancy (Days 12-13 and 15-16). Twenty-one proteins were identified that were uniquely expressed on the selected days of pregnancy or the oestrous cycle. Out of 21 identified proteins, 14 referred to the pregnancy periods. Systemic analysis of the identified proteins revealed cell adhesion and cytoskeletal organisation as two of the major functions, both of which are important for the establishment and maintenance of pregnancy. Thrombospondin 1 expression was validated using western blotting analysis and the results suggest its involvement in the adhesiveness of the embryo during the peri-implantation period in pigs.