| 1 | PLoS ONE 2012 -1 7: e43904 |
|---|---|
| PMID | 22937123 |
| Title | Selective expression of KCNS3 potassium channel ?-subunit in parvalbumin-containing GABA neurons in the human prefrontal cortex. |
| Abstract | The cognitive deficits of schizophrenia appear to be associated with altered cortical GABA neurotransmission in the subsets of inhibitory neurons that express either parvalbumin (PV) or somatostatin (SST). Identification of molecular mechanisms that operate selectively in these neurons is essential for developing targeted therapeutic strategies that do not influence other cell types. Consequently, we sought to identify, in the human cortex, gene products that are expressed selectively by PV and/or SST neurons, and that might contribute to their distinctive functional properties. Based on previously reported expression patterns in the cortex of mice and humans, we selected four genes: KCNS3, LHX6, KCNAB1, and PPP1R2, encoding K(+) channel Kv9.3 modulatory ?-subunit, LIM homeobox protein 6, K(+) channel Kv?1 subunit, and protein phosphatase 1 regulatory subunit 2, respectively, and examined their colocalization with PV or SST mRNAs in the human prefrontal cortex using dual-label in situ hybridization with (35)S- and digoxigenin-labeled antisense riboprobes. KCNS3 mRNA was detected in almost all PV neurons, but not in SST neurons, and PV mRNA was detected in >90% of KCNS3 mRNA-expressing neurons. LHX6 mRNA was detected in almost all PV and >90% of SST neurons, while among all LHX6 mRNA-expressing neurons 50% expressed PV mRNA and >44% expressed SST mRNA. KCNAB1 and PPP1R2 mRNAs were detected in much larger populations of cortical neurons than PV or SST neurons. These findings indicate that KCNS3 is a selective marker of PV neurons, whereas LHX6 is expressed by both PV and SST neurons. KCNS3 and LHX6 might be useful for characterizing cell-type specific molecular alterations of cortical GABA neurotransmission and for the development of novel treatments targeting PV and/or SST neurons in schizophrenia. |
| SCZ Keywords | schizophrenia |
| 2 | Biol. Psychiatry 2013 May 73: 1024-34 |
| PMID | 23348010 |
| Title | Social isolation exacerbates schizophrenia-like phenotypes via oxidative stress in cortical interneurons. |
| Abstract | Our previous studies indicated that N-methyl-D-aspartate receptor (NMDAR) deletion from a subset of corticolimbic interneurons in the mouse brain during early postnatal development is sufficient to trigger several behavioral and pathophysiological features resembling the symptoms of human schizophrenia. Interestingly, many of these behavioral phenotypes are exacerbated by social isolation stress. However, the mechanisms underlying the exacerbating effects of social isolation are unclear. With ?-aminobutyric acid-ergic interneuron-specific NMDAR hypofunction mouse model (PPP1R2-Cre/fGluN1 knockout [KO] mice), we investigated whether oxidative stress is implicated in the social isolation-induced exacerbation of schizophrenia-like phenotypes and further explored the underlying mechanism of elevated oxidative stress in KO mice. The reactive oxygen species (ROS) level in the cortex of group-housed KO mice was normal at 8 weeks although increased at 16 weeks old. Postweaning social isolation (PWSI) augmented the ROS levels in KO mice at both ages, which was accompanied by the onset of behavioral phenotype. Chronic treatment with apocynin, an ROS scavenger, abolished markers of oxidative stress and partially alleviated schizophrenia-like behavioral phenotypes in KO mice. Markers of oxidative stress after PWSI were especially prominent in cortical parvalbumin (PV)-positive interneurons. The vulnerability of PV interneurons to oxidative stress was associated with downregulation of peroxisome proliferator-activated receptor ? coactivator-1? (PGC-1?), a master regulator of mitochondrial energy metabolism and antioxidation. These results suggest that a PWSI-mediated impairment in antioxidant defense mechanisms, presumably mediated by PGC-1? downregulation in the NMDAR-deleted PV-positive interneurons, results in oxidative stress, which, in turn, might contribute to exacerbation of schizophrenia-like behavioral phenotypes. |
| SCZ Keywords | schizophrenia |