Expression of Dpp6 in mouse embryonic craniofacial development

Dipeptidyl-peptidase-like protein 6 (DPP6), a member of the dipeptidyl aminopeptidase family, plays distinct roles in brain development, but its expression in embryonic craniofacial development is unknown. The expression pattern of Dpp6 in the maxillofacial region during mouse embryonic craniofacial development was analyzed by whole-mount in situ hybridization on sections and by real-time PCR analysis. Dpp6 expression was detected during mouse embryonic craniofacial development in embryos 11-13.5 days post-coitum (dpc). Real-time PCR showed high Dpp6 expression present in 11.5-13.5 dpc, and this then decreased as development of maxillofacial region progressed. The expression pattern of Dpp6 suggests that Dpp6 may be involved in embryonic craniofacial development.     

Trmt112 gene expression in mouse embryonic development

Mouse Trmt112, the homologous gene of yeast Trm112 (tRNA methyltransferase 11-2), was initially cloned from RIKEN with uncertain function. The yeast TRM112 is now known to play important roles in RNA methylation. Here, we studied the expression of Trmt112 by in situ hybridization and quantitative real-time RT-PCR (QRT-PCR). A higher expression level of Trmt112 was observed in the brain and nervous system by whole mount in situ hybridization from embryonic day 10.5 (E10.5) to E11.5. At later developmental stages E13.5 and E16.5, abundant expression was prominently found in various organs and tissues including developing brain, nervous system, thymus, lung, liver, intestine, kidney, and cartilage. Furthermore, Trmt112 was persistently expressed from E9.5 to E18.5 on whole embryos and highly expressed in multiple organs at E12.5, E15.5 and E18.5 by QRT-PCR. These results showed that Trmt112 gene was highly and ubiquitously expressed during mouse embryonic development, implying that it might be involved in the morphogenesis of diverse organs and tissues and numerous physiological functions.     

Expression of macro non-coding RNAs Meg8 and Irm in mouse embryonic development

Non-coding RNAs (ncRNAs) Meg8 and Irm were previously identified as alternatively splicing isoforms of Rian gene. Ascertaining ncRNAs spatiotemporal expression patterns is crucial for understanding the physiological roles of ncRNAs during tissue and organ development. In this study in mouse embryos, we focused on the developmental regulation expression of imprinted macro ncRNAs, Meg8 and Irm by using in situ hybridization and quantitative real-time RT-PCR (QRT-PCR). The in situ hybridization results showed that Meg8 and Irm were expressed in the developing brain at embryonic day 10.5 (E10.5) and E11.5, while Irm expression signals were strikingly detected in the somite, where Meg8 expression signals were undetectable. By E15.5, they were expressed in brain, tongue, liver, lung and neuroendocrine tissues, while Irm displayed more restricted expression in tongue and skeletal muscle than Meg8. Furthermore, quantitative analysis confirmed that they were highly expressed in tongue and brain at E12.5, E15.5 and E18.5. These results indicated that Meg8 and Irm might be coordinately expressed and functionally correlated in diverse of organs. Notably, Irm was more closely associated with morphogenesis of skeletal muscle in contrast to Meg8 during embryonic development.     

Comparative analysis of respiratory chain and oxidative phosphorylation in Leishmania tarentolae, Crithidia fasciculata, Phytomonas serpens and procyclic stage of Trypanosoma brucei

Trypanosomatids are unicellular parasites living in a wide range of host environments, which to large extent shaped their mitochondrial energy metabolism, resulting in quite large differences even among closely related flagellates. In a comparative manner, we analyzed the activities and composition of mitochondrial respiratory complexes in four species (Leishmania tarentolae, Crithidia fasciculata, Phytomonas serpens and Trypanosoma brucei), which represent the main model trypanosomatids. Moreover, we measured the activity of mitochondrial glycerol-3-phosphate dehydrogenase, the overall oxygen consumption and the mitochondrial membrane potential in each species. The comparative analysis suggests an inverse relationship between the activities of respiratory complexes I and II, as well as the overall activity of the canonical complexes and glycerol-3-phosphate dehydrogenase. Our comparative analysis shows that mitochondrial functions are highly variable in these versatile parasites     

Decreased gene expression of neuropeptide Y and its receptors in hippocampal regions during ethanol withdrawal in rats

Ethanol withdrawal is associated with neuronal hyperexcitability and increased hippocampal glutamate release. Neuropeptide Y (NPY) appears to play an important role in regulation of hippocampal neuronal excitability by inhibiting glutamate release. Expression of NPY and its receptors Y1, Y2, and Y5 was studied in hippocampal areas of rats during ethanol withdrawal after repeated intragastric ethanol administration for 2 or 4 days using in situ hybridization. Withdrawal was associated with decreased hippocampal expression of NPY and each of its receptors, particularly Y2, after 2 and/or 4 days of ethanol compared to control rats. These data suggest that the hippocampal NPY system is downregulated during ethanol withdrawal and these neuroadaptational changes could play a role in mediating withdrawal hyperexcitability.     

Virulence attributes of Histophilus somni with a deletion mutation in the ibpA gene

Histophilus somni strain 2336 contains a large open reading frame of 12,285-bp length, ibpA, encoding the immunoglobulin binding protein (IbpA) which is associated with H. somni serum resistance. To elucidate other functions of the strain 2336 IbpA protein, an ibpA isogenic mutant, 2336.A1, was created by replacement of an 11.6-kb ibpA sequence with a kanamycin resistant gene cassette. Both the mutant strain 2336.A1 and the wild-type strain 2336 adhered at similar levels to bovine turbinate cells, bovine endometrial epithelial cells and bovine macrophage-like FBM-17 cells. However, a remarkable cytotoxic effect associated with disruption of actin filaments was observed in FBM-17 cells infected with strain 2336 but not with strain 2336.A1. Cytotoxicity was also noted with the wild type but not the mutant in assays with murine J774.1 macrophage cells and bovine primary monocytes. Inhibition of phagocytosis of microspheres was found in assays with murine J774.1 cells and bovine primary monocytes infected with strain 2336 but not with strain 2336.A1. These results indicate that H. somni IbpA protein inhibits phagocytic activity of macrophages and monocytes, probably by disruption of actin filament structure.     

Panic disorder and serotonergic genes (SLC6A4, HTR1A and HTR2A): Association and interaction with childhood trauma and parenting

Objective

The aim of this study is to evaluate the association between HTR1A, HTR2A and the 5-HTTLPR in panic disorder (PD) patients and controls. In addition, this study also aims to evaluate the interaction between these genes and two environmental factors previously associated with PD: childhood trauma and parental bonding.

Methods

This is a case–control candidate gene association study (107 PD patients and 125 controls). Genes were analyzed using a gene-based test in PLINK followed by single marker association tests and haplotype test only for genes that reached experiment-wide significance in the gene-based test in order to minimize multiple testing. Logistic regression was used to test the relationships between genotype in the additive model, trauma, optimal paternal parenting and optimal maternal parenting and their interactions.

Results

Only HTR1A was associated with PD in gene-based test after correction for multiple tests (p_corrected = 0.027) and one HTR1A haplotype comprising four SNPs was associated with PD (p_corrected = 0.032). In the interaction analysis, no significant gene–environment interaction was found with the genes evaluated.

Conclusion

This study reinforces the association between HTR1A and PD. No major evidence of gene–environment interaction in PD with parenting or trauma was found. Further studies are necessary in order to confirm these findings.     

Differential susceptibility of inbred mouse strains to Burkholderia thailandensis aerosol infection

Burkholderia pseudomallei is the causative agent of melioidosis, an emerging bacterial disease that accounts for high rates of septicaemia and death in parts of Southeast Asia and Northern Australia. The closely related species Burkholderia thailandensis is considered avirulent in humans and has been used as a surrogate for B. pseudomallei in several studies. The pathogenesis of B. pseudomallei and the role of Toll-like receptors (TLRs) in host immunity to infection are not well-defined. In this study, we exposed four strains of inbred mice (BALB/c, C57BL/6, TLR4-deficient C3H/HeJ, and TLR4-competent C3H/HeN) to increasing doses of aerosolized B. thailandensis to determine strain susceptibility and the role of TLR4 during pulmonary infection. Our results indicate an increased susceptibility in the C57BL/6 and BALB/c strains, who displayed lethality, bacterial burden in organs, and pulmonary and systemic inflammation. C3H/HeJ were as resistant as C3H/HeN mice to B. thailandensis at the highest challenge dose examined, but TLR4-deficient animals exhibited a modest increase in chronic pulmonary inflammation. These results demonstrate that B. thailandensis can be used as a surrogate for experimental laboratory investigation of melioidosis in small animal models and that TLR4 may not play a prominent role during acute pneumonic melioidosis.     

Investigation of TREM2, PLD3, and UNC5C variants in patients with Alzheimer's disease from mainland China

Recently, 3 rare coding variants significantly associated with Alzheimer's disease (AD) risk have been identified in western populations using whole exome sequencing method, including p.R47H in TREM2, p.V232M in PLD3, and p.T835M in UNC5C. To examine whether these variants are genetic risk factors in patients with AD from mainland China, we sequenced exon 2 of TREM2, exon 9 of PLD3, and exon 15 of UNC5C in Chinese Han population including 360 patients with AD and 400 control individuals. As a result, none of these 3 variants were identified in all subjects, however, 1 novel variant (p.A130V) in TREM2 and 4 novel variants (p.Q860H, p.T837K, p.S843G, and p.V836V) in UNC5C were detected in unrelated patients with late-onset AD. These findings suggest the 3 rare coding variants might not play an important role in AD risk in mainland China.     

The serotonin transporter gene and startle response during nicotine deprivation

Affective startle probe methodology was used to examine the effects of nicotine administration and deprivation on emotional processes among individuals carrying at least one s allele versus those with the l/l genotype of the 5-Hydroxytryptamine (Serotonin) Transporter Linked Polymorphic Region, 5-HTTLPR in the promoter region of the serotonin transporter gene [solute ligand carrier family 6 member A4 (SLC6A4) or SERT]. Smokers (n = 84) completed four laboratory sessions crossing deprivation (12-h deprived vs. non-deprived) with nicotine spray (nicotine vs. placebo). Participants viewed affective pictures (positive, negative, neutral) while acoustic startle probes were administered. We found that smokers with the l/l genotype showed significantly greater suppression of the startle response when provided with nicotine vs. placebo than those with the s/s or s/l genotypes. The results suggest that l/l smokers, who may have higher levels of the serotonin transporter and more rapid synaptic serotonin clearance, experience substantial reduction in activation of the defensive system when exposed to nicotine.     

Clinical and genetic analysis of MAPT, GRN, and C9orf72 genes in Korean patients with frontotemporal dementia

The hexanucleotide repeat expansion (GGGGCC) in chromosome 9 open-reading frame 72 (C9orf72) and mutations in the microtubule-associated protein tau (MAPT) and progranulin (GRN) genes are known to be associated with the main causes of familial or sporadic amyotrophic lateral sclerosis and frontotemporal dementia (FTD) in Western populations. These genetic abnormalities have rarely been studied in Asian FTD populations. We investigated the frequencies of mutations in MAPT and GRN and the C9orf72 abnormal expansion in 75 Korean FTD patients. Two novel missense variants of unknown significance in the MAPT and GRN were detected in each gene. However, neither abnormal C9orf72 expansion nor pathogenic MAPT or GRN mutation was found. Our findings indicate that MAPT, GRN, and C9orf72 mutations are rare causes of FTD in Korean patients.     

Characterization of biofilms formed by Candida parapsilosis, C. metapsilosis, and C. orthopsilosis

Infections due to Candida parapsilosis have been associated with the ability of this fungus to form biofilms on indwelling medical devices. Recently, C. parapsilosis isolates were reclassified into 3 genetically non-identical classes: C. parapsilosis, C. orthopsilosis, and C. metapsilosis. Little information is available regarding the ability of these newly reclassified species to form biofilms on biomedical substrates. In this study, we characterized biofilm formation by 10 clinical isolates each of C. parapsilosis, C. orthopsilosis, and C. metapsilosis. Biofilms were allowed to form on silicone elastomer discs to early (6 h) or mature (48 h) phases and quantified by tetrazolium (XTT) and dry weight assays. Surface topography and three-dimensional architecture of the biofilms were visualized using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), respectively. Metabolic activity assay revealed strain-dependent biofilm forming ability of the 3 species tested, while biomass determination revealed that all 3 species formed equivalent biofilms (P>0.05 for all comparisons). SEM analyses of representative isolates of these species showed biofilms with clusters of yeast cells adherent to the catheter surface. Additionally, confocal microscopy analyses showed the presence of cells embedded in biofilms ranging in thickness between 62 and 85 μm. These results demonstrate that similar to C. parapsilosis, the 2 newly identified Candida species (C. orthopsilosis and C. metapsilosis) were able to form biofilms.