Reduced hippocampal inhibition and enhanced autism-epilepsy comorbidity in mice lacking neuropilin 2

The neuropilin receptors and their secreted semaphorin ligands play key roles in brain circuit development by regulating numerous crucial neuronal processes, including the maturation of synapses and migration of GABAergic interneurons. Consistent with its developmental roles, the neuropilin 2 (Nrp2) locus contains polymorphisms in patients with autism spectrum disorder (ASD). Nrp2-deficient mice show autism-like behavioral deficits and propensity to develop seizures. In order to determine the pathophysiology in Nrp2 deficiency, we examined the hippocampal numbers of interneuron subtypes and inhibitory regulation of hippocampal CA1 pyramidal neurons in mice lacking one or both copies of Nrp2. Immunostaining for interneuron subtypes revealed that Nrp2−/− mice have a reduced number of parvalbumin, somatostatin, and neuropeptide Y cells, mainly in CA1. Whole-cell recordings identified reduced firing and hyperpolarized shift in resting membrane potential in CA1 pyramidal neurons from Nrp2+/− and Nrp2−/− mice compared to age-matched wild-type controls indicating decrease in intrinsic excitability. Simultaneously, the frequency and amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs) are reduced in Nrp2-deficient mice. A convulsive dose of kainic acid evoked electrographic and behavioral seizures with significantly shorter latency, longer duration, and higher severity in Nrp2−/− compared to Nrp2+/+ animals. Finally, Nrp2+/− and Nrp2−/− but not Nrp2+/+, mice have impaired cognitive flexibility demonstrated by reward-based reversal learning, a task associated with hippocampal circuit function. Together these data demonstrate a broad reduction in interneuron subtypes and compromised inhibition in CA1 of Nrp2−/− mice, which could contribute to the heightened seizure susceptibility and behavioral deficits consistent with an ASD/epilepsy phenotype.

Reduced Hippocampal Inhibition and Enhanced Autism-Epilepsy Comorbidity in Mice Lacking Neuropilin 2

The neuropilin receptors and their secreted semaphorin ligands play key roles in brain circuit development by regulating numerous crucial neuronal processes, including the maturation of synapses and migration of GABAergic interneurons. Consistent with its developmental roles, the neuropilin 2 (Nrp2) locus contains polymorphisms in patients with autism spectrum disorder (ASD). Nrp2 deficient mice show autism-like behavioral deficits and propensity to develop seizures. In order to determine the pathophysiology in Nrp2 deficiency, we examined the hippocampal numbers of interneuron subtypes and inhibitory regulation of hippocampal CA1 pyramidal neurons in mice lacking one or both copies of Nrp2. Immunostaining for interneuron subtypes revealed that Nrp2-/- mice have reduced number of parvalbumin, somatostatin and Neuropeptide Y cells, mainly in CA1. Whole cell recordings identified reduced firing and hyperpolarized shift in resting membrane potential in CA1 pyramidal neurons from Nrp2+/- and Nrp2-/- mice compared to age-matched wild-type controls indicating decrease in intrinsic excitability. Simultaneously, the frequency and amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs) are reduced in Nrp2 deficient mice. A convulsive dose of kainic acid evoked electrographic and behavioral seizures with significantly shorter latency, longer duration and higher severity in Nrp2-/- compared to Nrp2+/+ animals. Finally, Nrp2+/- and Nrp2-/-, but not Nrp2+/+, mice have impaired cognitive flexibility demonstrated by reward-based reversal learning, a task associated with hippocampal circuit function. Together these data demonstrate a broad reduction in interneuron subtypes and compromised inhibition in CA1 of Nrp2-/- mice, which could contribute to the heightened seizure susceptibility and behavioral deficits consistent with an ASD/epilepsy phenotype.

Homeodomain Transcription Factors: Integral Modulators of Human Decidualization

Ineffective embryo implantation accounts for a significant percentage of female infertility, and often renders IVF procedures unsuccessful. Decidualization, the dramatic uterine morphological response to ovarian hormone exposure, is a prerequisite for embryo implantation. Despite its significance in reproduction, the genetic framework of decidualization was not systematically studied until our recent development of a suitable high-throughput screening tool, immortalized human endometrial stromal cells (hESCs) that carry the yellow fluorescent protein gene under the control of the progesterone-sensitive prolactin promoter (PRL-Y cells). We recently used PRL-Y cells to perform a genome-wide siRNA functional screen and results revealed that 36 members of the homeodomain-containing family of transcription factors (HDTFs) are modulators of human decidualization. To determine which HDTFs are transcriptionally sensitive to ovarian hormone exposure, RT-PCR was performed on wildtype hESCs for the 36 HDTF hits over a 72-hour time course of E2/P4/cAMP exposure. Twenty HDTF hits (55%) were both detectable by PCR and showed variable expression in response to ovarian hormone treatment. Interestingly, all of these homeodomain factors, with a few distinct exceptions, exhibited decreased transcriptional expression in response to ovarian hormone treatment. This suggests that precious energy is used to transcribe these factors during the pre-decidualized phase, and that they may be required to maintain homeostasis during times of low hormone exposure. Because siRNA is not fully efficient, in order to confirm which HDTFs are required for normal decidualization, we generated a doxycyline-inducible Cas9-expressing hESC clone in order to subsequently generate individual knockout hESC lines for each HDTF hit. Cas9 expression was turned on 5 days prior to crRNA and trRNA transfection targeting the first exon of each HDTF. Five days after transfection, the cells were treated for 72 hours with ovarian hormone induction medium before RNA was isolated for gene expression analysis. As a pool of cells prior to any cloning (which likely includes knockout and wildtype cells in different ratios) the results indicate that several HDTFs are required for proper decidualization. The reporter transcripts of PRL and EREG are significantly abrogated or entirely undetectable in certain knockout lines. Interestingly these include some original siRNA HDTF hits whose expression is undetectably low by PCR. Sequencing validation will be necessary to confirm that knocking out such low levels of these transcripts genuinely has the robust effect on the human decidualization reaction that we are witnessing in these results. Together these findings comprise significant initial steps in characterizing the intricate upstream roles of HDTFs in human decidualization and female fertility.

Erythrocyte miRNA 144 and miRNA 451 as Cell Aging Biomarkers in African American Adults

Objective: MicroRNAs (miRNA) are novel critical regulators of cell proliferation and human disease, including diabetes mellitus and cancer. The aim of this study was to evaluate the expression of circulating erythrocytes (E) miRNA-144 and miRNA-451 expression in African Americans Adults (AAA) as a biomarker of cell aging. Methods: The blood samples were collected from healthy controls [n=9] following an 8-12 hours fast. Erythrocytes were purified twice by Boyum gradient. Erythrocytes were further sub-fractionated into young (y) (1.07-1.09 g/ml), mid (m) (1.09- 1.11 g/ml), and old (o) (1.11-1.12 g/ml) age cells by using discontinuous Percoll gradient (35%, 40%, 45%, 50%, 55%, 65%, 80%, and 100%) and total RNA extracted. MiRNA-144 and miRNA-451 were quantified in y, m, and o age E sub-fractions by qRT-PCR. Results: MiRNA-451 expression was 82210.8271, 130922.476, and 149554.364 in y, m, and o cells, respectively. MiRNA-144 expression in y cells was 18.6641092, m cells was 32.4413621, and o cells was 57.8118394 These results showed that o cells expressed both miRNA-144 and miRNA-451 more than that of m, and y cells. Conclusion: The findings of this study showed that miRNAs expression differ in sub-fractionated erythrocytes. This study suggests that miRNA-144 and miRNA-451 have the potential to be used as biomarkers of RBC aging.

Molecular studies of NAD- and NADP- glutamate dehydrogenases decipher the conundrum of yeast-hypha dimorphism in zygomycete Benjaminiella poitrasii

Benjaminiella poitrasii, a zygomycete shows glucose and temperature dependent yeast (Y)-hypha (H) dimorphic transition. Earlier we reported the biochemical correlation of relative proportion of NAD- and NADP- glutamate dehydrogenases (GDH) with Y-H transition. Further, we observed the presence of one NAD-GDH and two form–specific NADP-GDH isoenzymes in B. poitrasii. However, molecular studies are necessary to elucidate the explicit role of GDHs in regulating Y-H reversible transition. Here, we report the isolation and characterization of one NAD- (BpNADGDH, 2.643 kb) and two separate genes, BpNADPGDH I (Y form specific, 1.365 kb) and BpNADPGDH II (H form specific, 1.368 kb) coding for NADP-GDH isoenzymes in B. poitrasii. The transcriptional profiling during Y-H transition showed higher BpNADPGDH I expression in Y cells while expression of BpNADPGDH II was higher in H cells. Moreover, the yeast form monomorphic mutant (Y-5) did not show BpNADPGDH II expression under normal dimorphism triggering conditions. Transformation with H form specific BpNADPGDH II induced the germ tube formation in Y-5, which confirmed the cause-effect relationship between BpNADPGDH genes and morphological outcome in B. poitrasii. Interestingly, expression of H-form specific BpNADPGDH II also induced germ tube formation in human pathogenic, non-dimorphic yeast Candida glabrata, which further corroborated our findings.

Development of a Standard Curve to Account for Viable Loads of Bifidobacterium animalis subsp. lactis HN019 Using RNA by Real-Time PCR

Background: Bifidobacterium animalis subsp. lactis HN019 is widely used as a probiotic in various dairy preparations. To ensure optimal health benefits, an adequate number of probiotics should be viable in products, but the culture-based methods require longer periods to account for the strain. Objective: Develop a standard curve to account viable loadof B. animalis subsp. lactis HN019 by real-time PCR. Methods: The growth curve was developed accordingto plate count method, and cycle threshold (CT) curve was prepared using CT values. These two curves were then combined to construct the standard curve. To validate the method, the strain was proliferated in whole milk, and viable loads were enumerated by plate counting and relativePCR counting followed by determining the SEM betweenthe two counts. Results: The growth curve and CT curve, respectively, showed the highest viable load (2.13 × 108 CFU/mL) and lowest CT value (18.29) after 18 h, and during the entire growth phase (0–18 h), viable loads are inversely proportional to the CT values. The standard curverevealed the model y = 2E + 18e−1.233x (y = cells/mL, x = CT value; R2 = 0.992). In validation, the highest SEM (± 0.70 × 108) was found between the plate count (1.15 × 108 cells/mL) and relative PCR count (1.29 × 108 cells/mL) after cultivating for 14 h. Conclusions: The method could be readilyused in dairy industries to quantify viable B. animalis subsp. lactis HN019 by a shorter period. Highlights: Culture-independent enumeration of viable B. animalis subsp. lactis HN019 by real-time PCR.

Can the Outputs of LGN Y-Cells Support Emotion Recognition? A Computational Study

It has been suggested that emotional visual input is processed along both a slower cortical pathway and a faster subcortical pathway which comprises the lateral geniculate nucleus (LGN), the superior colliculus, the pulvinar, and finally the amygdala. However, anatomical as well as functional evidence concerning the subcortical route is lacking. Here, we adopt a computational approach in order to investigate whether the visual representation that is achieved in the LGN may support emotion recognition and emotional response along the subcortical route. In four experiments, we show that the outputs of LGN Y-cells support neither facial expression categorization nor the same/different expression matching by an artificial classificator. However, the same classificator is able to perform at an above chance level in a statistics-based categorization of scenes containing animals and scenes containing people and of light and dark patterns. It is concluded that the visual representation achieved in the LGN is insufficient to allow for the recognition of emotional facial expression.