Anti-PUM2 (aa 701-798) polyclonal antibody

Chronic exposure to cocaine in vivo induces long-term synaptic plasticity associated with the brain's circuitry that underlies development of repetitive and automatic behaviors called habits. In fact, prolonged drug consumption results in aberrant expression of protein-coding genes and small regulatory RNAs, including miRNAs that are involved in synaptic plasticity and neuroadaptations. However, the mechanisms mediating cocaine use disorder are still not fully understood. The present study is designed to examine the expression of miR-124, miR-132, miR-134, and miR-212, as well as the levels of the Ago2, Pum2, and REST mRNAs and proteins implicated in their regulation. We applied rat cocaine self-administration (SA) and extinction training procedures with a yoked triad to assess the changes in the levels of four miRNAs and three protein-coding genes and corresponding proteins in the dorsal striatum. We demonstrated that elevated expression of mature miR-212 and miR-132 is long-lasting and persists in the drug-free period (till 10-day abstinence). Moreover, mRNA and protein of REST, a regulator of neuronal transcription, was raised selectively in cocaine self-administering rats and Ago2 transcript decreased after cocaine treatment. Unexpectedly, the expression level of Ago2 and Pum2 proteins changed only in the active cocaine-receiving animals. These results point out the important aspects of long-lasting alterations in microRNAs, genes, and protein expressions involved in the control of synaptic plasticity associated with reward and motivation learning related to cocaine addiction.

Self-renewal is the common functional property of all types of stem cells and is thought to be regulated by unknown conserved intrinsic and extrinsic molecular mechanisms. Recently, an evolutionarily conserved Pumilio family of RNA-binding proteins that regulate asymmetric cell division was found to be essential for stem cell maintenance and self-renewal in Drosophila and Caenorhabditis elegans. Based on conserved function in invertebrates and lower vertebrates it was recently proposed that an ancestral function of Pumilio proteins is to support proliferation and self-renewal of stem cells. This raises an interesting possibility that Pumilio could be part of evolutionarily conserved intrinsic molecular mechanism that regulates self-renewal of mammalian stem cells. Here we describe cloning and comparative sequence analysis of Pum1 and Pum2 genes, mouse members of the Punfilio family, and for the first time demonstrate expression of Pumilio genes in mammalian hematopoietic stem cells (HSQ. Pum1 and Puin2 share 51 and 55% overall similarity with the fly Pum, whereas their RNA-binding domains show a very high degree of evolutionary conservation (86-88% homology). Both genes are expressed in a variety of tissues suggesting that they have widespread function. During blood cell development Pum1 and Pum2 exhibit differential expression in cell populations enriched for HSC and progenitors. Both genes are highly transcribed in populations of adult HSC (Rho-123(low)Sca-1(+)c-kit(+)Lin(-) cells). In a more heterogeneous population of HSC (Lin(-)Sca-1(+)) and in progenitors (Lin(-)Sca-1(-) cells) Punt] is not transcribed, whereas Pum2 expression is significantly down-regulated. Ongoing in vitro and in vivo functional analysis of mouse Pumilio genes will help to elucidate the biological role of mammalian Pumilio genes and determine whether they play any role in maintenance of mammalian stem cells, such as HSC. (C) 2003 Elsevier Science (USA). All rights reserved.