Polyunsaturated fatty acid deficiency during neurodevelopment in mice models the prodromal state of schizophrenia through epigenetic changes in nuclear receptor genes.

The risk of schizophrenia is increased in offspring whose mothers experience malnutrition during pregnancy. Polyunsaturated fatty acids (PUFAs) are dietary components that are crucial for the structural and functional integrity of neural cells, and PUFA deficiency has been shown to be a risk factor for schizophrenia. Here, we show that gestational and early postnatal dietary deprivation of two PUFAs-arachidonic acid (AA) and docosahexaenoic acid (DHA)-elicited schizophrenia-like phenotypes in mouse offspring at adulthood. In the PUFA-deprived mouse group, we observed lower motivation and higher sensitivity to a hallucinogenic drug resembling the prodromal symptoms in schizophrenia. Furthermore, a working-memory task-evoked hyper-neuronal activity in the medial prefrontal cortex was also observed, along with the downregulation of genes in the prefrontal cortex involved in oligodendrocyte integrity and the gamma-aminobutyric acid (GABA)-ergic system. Regulation of these genes was mediated by the nuclear receptor genes Rxr and Ppar, whose promoters were hyper-methylated by the deprivation of dietary AA and DHA. In addition, the RXR agonist bexarotene upregulated oligodendrocyte- and GABA-related gene expression and suppressed the sensitivity of mice to the hallucinogenic drug. Notably, the expression of these nuclear receptor genes were also downregulated in hair-follicle cells from schizophrenia patients. These results suggest that PUFA deficiency during the early neurodevelopmental period in mice could model the prodromal state of schizophrenia through changes in the epigenetic regulation of nuclear receptor genes.

Analysis of induced pluripotent stem cells carrying 22q11.2 deletion.

Given the complexity and heterogeneity of the genomic architecture underlying schizophrenia, molecular analyses of these patients with defined and large effect-size genomic defects could provide valuable clues. We established human-induced pluripotent stem cells from two schizophrenia patients with the 22q11.2 deletion (two cell lines from each subject, total of four cell lines) and three controls (total of four cell lines). Neurosphere size, neural differentiation efficiency, neurite outgrowth, cellular migration and the neurogenic-to-gliogenic competence ratio were significantly reduced in patient-derived cells. As an underlying mechanism, we focused on the role of DGCR8, a key gene for microRNA (miRNA) processing and mapped in the deleted region. In mice, Dgcr8 hetero-knockout is known to show a similar phenotype of reduced neurosphere size (Ouchi et al., 2013). The miRNA profiling detected reduced expression levels of miRNAs belonging to miR-17/92 cluster and miR-106a/b in the patient-derived neurospheres. Those miRNAs are reported to target p38α, and conformingly the levels of p38α were upregulated in the patient-derived cells. p38α is known to drive gliogenic differentiation. The inhibition of p38 activity by SB203580 in patient-derived neurospheres partially restored neurogenic competence. Furthermore, we detected elevated expression of GFAP, a gliogenic (astrocyte) marker, in postmortem brains from schizophrenia patients without the 22q11.2 deletion, whereas inflammation markers (IL1B and IL6) remained unchanged. In contrast, a neuronal marker, MAP2 expressions were decreased in schizophrenia brains. These results suggest that a dysregulated balance of neurogenic-to-gliogenic competence may underlie neurodevelopmental disorders such as schizophrenia.

Alteration of inhibitory properties of Pleurotus ostreatus proteinase A inhibitor 1 by mutation of its C-terminal region.

Pleurotus ostreatus proteinase A inhibitor 1 (POIA1), which is composed of 76 residues without disulfide bridges, is a unique inhibitor in that it exhibits sequence similarity to the propeptides of subtilisins. In order to elucidate the inhibitory mechanism of POIA1, we constructed an expression system for a synthetic POIA1 gene. The wild-type POIA1 was found to inhibit subtilisin BPN' with an inhibitor constant (K(i)) of 3.2 x 10(-9) M, but exhibited a time-dependent decrease of inhibitory activity as a consequence of degradation by the protease, showing that the wild-type POIA1 was a temporary inhibitor when subtilisin BPN' was used as a target protease. Since POIA1 shows sequence similarity to the propeptide of subtilisin, which is known to inhibit the protease via its C-terminal region, the C-terminal six residues of POIA1 were replaced with those of the propeptide of subtilisin BPN'. The mutated POIA1 inhibited subtilisin BPN' with a K(i) value of 2.8 x 10(-11) M and did not exhibit time-dependent decrease of inhibitory activity, showing about 100-fold increases in binding affinity for, and resistance to, the protease. These results clearly indicate that the C-terminal region of POIA1 plays an important role in determining the inhibitory activity toward the protease, and that the increase in binding ability to the protease is closely related to resistance to proteolytic degradation. Therefore, the inhibitory properties of POIA1 can be altered by mutation of its C-terminal region.

Microscale analysis of glycosphingolipids by TLC blotting/secondary ion mass spectrometry: a novel blood group A-active glycosphingolipid and changes in glycosphingolipid expression in rat mammary tumour cells with different metastatic potentials.

The glycosphingolipid compositions of rat mammary tumour cell lines with different metastatic potentials for the lung [a parental tumour cell line (MTC) and its subclones MTLn2 (a non metastatic subclone) and MTLn3 (a subclone with high metastatic potential to the lung)] were studied using a newly developed TLC blotting/secondary ion mass spectrometry system and crude glycosphingolipids obtained from 0.5-1 x 10(7) cells of each cell line. GM3 and GM2 were the major components of the MTC cell line, but they were very minor components in the MTLn2 and MTLn3 cell lines, GDla being the major ganglioside HexNAc-fucosyl-GMla was found in the MTLn2 cells by the TLC blotting/SIMS method, and the terminal sugar linkage was shown to be a blood group A-type structure by immunostaining. These findings suggest that the ganglioside is a novel type of blood group A-active ganglioside, GalNAc alpha 1-3(fuc alpha 1 -2)GMla. No blood group A-active lipid was present in MTLn3 cells, whereas Hex-GMla and neutral glycosphingolipids with more than 5 sugar residues were.

[Clinical evaluation of roxithromycin in odontogenic infection].

The clinical effectiveness and safety of roxithromycin (RU 28965, RU), a new macrolide antibiotic, were compared with those of josamycin (JM) using a double-blind method in the treatment of orofacial odontogenic infections. The diseases covered in this study were periodontal infections, pericoronal infections and osteitis of jaws. Drugs were administered for 3 to 7 days at daily doses of 300 mg (RU) and 1,200 mg (JM). A total of 270 cases was evaluated in this study. Results obtained are summarized as follows: 1. The clinical efficacy was evaluated through the judgement of doctors in charge of 247 cases (128 in the RU group and 119 in the JM group) and by a committee on the 3rd day of treatment in 243 cases (126 in the RU group and 117 in the JM group). Clinical efficacy rates according to the committee judgement were 78.6% for the RU group and 82.1% for the JM group. As for the evaluation through the doctors' judgement, they were 79.7% for the RU group and 73.1% for the JM group. There was no significant difference in clinical effectiveness between 2 groups according to these 2 methods of judgement. 2. Some side effects were observed in 4 cases (2.9% out of 136) treated with RU and in 3 cases (2.4% out of 126) treated with JM. No severe symptoms were observed. Abnormal changes in laboratory test values were noted among 7.9% in the RU group and 4.0% in the JM group. There were no significant differences in their safety between the 2 groups. 3. In terms of clinical usefulness, there were no significant differences between the 2 groups as well. From these results, it has been concluded that RU (daily dose 300 mg) is as effective as JM (daily dose 1,200 mg) in the treatment of orofacial odontogenic infections.