| 1 | Psychiatr. Genet. 2012 Aug 22: 168-76 |
|---|---|
| PMID | 22555153 |
| Title | Involvement of PTPN5, the gene encoding the striatal-enriched protein tyrosine phosphatase, in schizophrenia and cognition. |
| Abstract | Striatal-enriched protein tyrosine phosphatase (STEP) is a brain-specific member of the protein tyrosine phosphatase (PTP) family that has been implicated in learning and memory. In this study, we examined the association of the protein tyrosine phosphatase non-receptor 5 (PTPN5) gene, which encodes for STEP, with both schizophrenia and cognitive functioning in the Israeli Jewish population. A schizophrenia (SZ) case-control study of 868 participants was carried out (286 patients and 582 controls). Eleven PTPN5 tagging single-nucleotide polymorphisms (SNPs) were selected and single markers and haplotype association analyses were carried out. A cognitive variability study included 437 healthy women who completed a computerized cognitive battery. We performed univariate associations between the SNPs and cognitive performance. The possible functional role of these variants was examined by studying their association with gene expression levels in the brain. In the SZ study, we found a nominal association in the whole sample between rs4075664 and SZ. Male patients with SZ showed a more significant association for three SNPs (rs4075664, rs2278732, and rs4757710). Haplotypes of the studied SNPs were associated with SZ both in the overall sample and within the male subsample. Expression analysis provided some support for the effects of the associated SNPs on PTPN5 expression level. The cognitive variability study showed positive associations between PTPN5 SNPs and different cognitive subtests. Principal component analysis showed an 'attention index' neurocognitive component that was associated with two SNP pairs (rs10832983 × rs10766504 and rs7932938 × rs4757718). The results imply a model in which PTPN5 may play a role in normal cognitive functioning and contribute to aspects of the neuropathology of SZ. |
| SCZ Keywords | schizophrenia |
| 2 | Neuroscience 2014 Oct 278: 62-9 |
| PMID | 25130559 |
| Title | Downstream effects of striatal-enriched protein tyrosine phosphatase reduction on RNA expression in vivo and in vitro. |
| Abstract | Striatal-enriched protein tyrosine phosphatase (STEP) is a brain-specific tyrosine phosphatase that has been shown to de-phosphorylate several key neuronal signaling proteins, including kinases (extracellular signal-regulated kinase (ERK1/2), FYN, PYK2) and glutamate receptor subunits (N-methyl-d-aspartate receptor subtype 2B (NR2B), glutamate receptor 2 (GLUR2)). Step knock-out mice have increased phosphorylation of these substrates in the brain, with potential functional consequences in synaptic plasticity and cognitive tasks. It is therefore of interest to identify the molecular pathways and downstream transcriptional targets that are impacted by Step knockdown. In the present study, striatal RNA samples from Step wild-type, knock-out and heterozygous mice were hybridized to Affymetrix microarray chips and evaluated for transcriptional changes between genotypes. Pathway analysis highlighted Erk signaling and multiple pathways related to neurotrophin signaling, neuronal development and synaptic transmission. Potential genes of interest identified by microarray were confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) in the cortex and hippocampus, which shared several transcriptional alterations with the striatum. In order to evaluate Step knockdown in an in vitro system, a panel of genes were evaluated using qRT-PCR in rat cortical neurons that were transduced with lentivirus expressing short hairpin RNA against Step or a non-targeting control. Our data suggest that Step has a role in the expression of immediate early genes relevant to synaptic plasticity, in both in vitro and in vivo systems. |
| SCZ Keywords | schizophrenia |