1J. Biol. Chem. 2013 Oct 288: 30752-62
TitleTransgenic expression of microRNA-185 causes a developmental arrest of T cells by targeting multiple genes including Mzb1.
AbstractmiR-185 is a microRNA (miR) that targets Bruton's tyrosine kinase in B cells, with reductions in miR-185 linked to B cell autoantibody production. In hippocampal neurons, miR-185 targets both sarcoplasmic/endoplasmic reticulum calcium ATPase 2 and a novel Golgi inhibitor. This miR is haploinsufficient in 90-95% of individuals with chromosome 22q11.2 deletion syndrome, patients who can present with immune, cardiac, and parathyroid problems, learning disorders, and a high incidence of schizophrenia in adults. The reduced levels of miR-185 in neurons cause presynaptic neurotransmitter release. Many of the 22q11.2 deletion syndrome patients have a thymic hypoplasia, which results in a peripheral T cell lymphopenia and unusual T helper cell skewing. The molecular targets of miR-185 in thymocytes are unknown. Using an miR-185 T cell transgenic approach, increasing levels of miR-185 attenuated T cell development at the T cell receptor ? (TCR?) selection checkpoint and during positive selection. This caused a peripheral T cell lymphopenia. Mzb1, Nfatc3, and CAMK4 were identified as novel miR-185 targets. Elevations in miR-185 enhanced TCR-dependent intracellular calcium levels, whereas a knockdown of miR-185 diminished these calcium responses. These effects concur with reductions in Mzb1, an endoplasmic reticulum calcium regulator. Consistent with their haploinsufficiency of miR-185, Mzb1 levels were elevated in thymocyte extracts from several 22q11.2 deletion syndrome patients. Our findings indicate that miR-185 regulates T cell development through its targeting of several mRNAs including Mzb1.
SCZ Keywordsschizophrenia
2Cereb. Cortex 2014 Oct 24: 2694-706
TitleLate maternal hypothyroidism alters the expression of Camk4 in neocortical subplate neurons: a comparison with Nurr1 labeling.
AbstractMaternal thyroid hormones (THs) are essential for normal offspring's neurodevelopment even after onset of fetal thyroid function. This is particularly relevant for preterm children who are deprived of maternal THs following birth, are at risk of suffering hypothyroxinemia, and develop attention-deficit/hyperactivity disorder. Expression of neocortical Ca(2+)/calmodulin kinase IV (CAMK4), a genomic target of thyroid hormone, and nuclear receptor-related 1 protein (Nurr1), a postnatal marker of cortical subplate (SP) cells, was studied in euthyroid fetuses and in pups born to dams thyroidectomized in late gestation (LMH group, a model of prematurity), and compared with control and developmentally hypothyroid pups (C and MMI groups, respectively). In LMH pups, the extinction of heavy CAMK4 expression in an SP was 1-2 days delayed postnatally compared with C pups. The heavy CAMK4 and Nurr1 expression in the SP was prolonged in MMI pups, whereas heavy CAMK4 and Nurr1 expression in layer VIb remains at P60. The abnormal expression of CAMK4 in the cortical SP and in layer VIb might cause altered cortical connectivity affecting neocortical function.
SCZ Keywordsschizophrenia