Nop2 is expressed during proliferation of neural stem cells and in adult mouse and human brain

Abstract

The nucleolar protein 2 gene encodes a protein specific for the nucleolus. It is assumed that it plays a role in the synthesis of ribosomes and regulation of the cell cycle. Due to its link to cell proliferation, higher expression of Nop2 indicates a worse tumor prognosis. In this work we used Nop2(gt1gaj) gene trap mouse strain. While lethality of homozygous animals suggested a vital role of this gene, heterozygous animals allowed the detection of expression of Nop2 in various tissues, including mouse brain. Histochemistry, immunohistochemistry and immunoelectron microscopy techniques, applied to a mature mouse brain, human brain and on mouse neural stem cells revealed expression of Nop2 in differentiating cells, including astrocytes, as well as in mature neurons. Nop2 was detected in various regions of mouse and human brain, mostly in large pyramidal neurons. In the human, Nop2 was strongly expressed in supragranular and infragranular layers of the somatosensory cortex and in layer III of the cingulate cortex. Also, Nop2 was detected in CA1 and the subiculum of the hippocampus. Subcellular analyses revealed predominant location of Nop2 within the dense fibrillar component of the nucleolus. To test if Nop2 expression correlates to cell proliferation occurring during tissue regeneration, we induced strokes in mice by middle cerebral artery occlusion. Two weeks after stroke, the number of Nop2/nestin double positive cells in the region affected by ischemia and the periventricular zone substantially increased. Our findings suggest a newly discovered role of Nop2 in both mature neurons and in cells possibly involved in the regeneration of nervous tissue.

Improved biocompatibility and efficient labeling of neural stem cells with poly(L-lysine)-coated maghemite nanoparticles

“…Neural stem cells (NSCs) were isolated from pregnant female mice as previously described [28–29]. Briefly, at gestation day 14.5, embryos were isolated and the telencephalic wall was microdissected and dissociated using StemPro Accutase (Life Technologies).…”

Nucleolar protein NOP2/NSUN1 suppresses HIV-1 transcription and promotes viral latency by competing with Tat for TAR binding and methylation

“…NOP2 is required for RNA processing and/or stability in vivo during preimplantation embryo development in the mouse [12]. NOP2 expresses at the higher level in the majority of human malignant tumor cells [13], and is considered as a prognostic marker for cancer aggressiveness. NOP2 also associates with the telomerase to regulate transcription of cyclin D1gene [14].…”

Identification of key regulators in Prostate cancer from gene expression datasets of patients

“…Due to this activity, HSPA5 is an emerging therapeutic drug target for cancer. NOP2 (p120) is a putative RNA methyl transferase protein and its expression is detectable in proliferating normal and tumour cells, but undetectable in non-proliferating normal cells (74,75,76). Its role in regulating cell cycle progression from G1 to S phase and transformation of normal fibroblast cells (77,78) makes NOP2 an interesting protein which can be used as biomarker for cell transformation.…”