Loss of the miR379-410 cluster in mice leads to alterations in social and anxiety-related behaviours

microRNAs (miRNAs) belong to a group of small non-coding RNAs that down regulates gene expression at the post-transcriptional level. The paternally imprinted placental mammal-specific miR379-410 cluster hosts 38 miRNAs. In the last decade, several members of the cluster have been shown to regulate synapse development and plasticity in mammals. Further, they have been implicated in a variety of diseases, including neurodevelopmental disorders. However, the potential involvement of these miRNAs in the control of complex behaviour in mammals, such as sociability, remains largely unknown. This is an important issue since aberrant synaptic dysfunction is thought to underlie neurodevelopmental diseases, such as autism spectrum disorder (ASD), characterized by deficits in social communication and interaction as well as restricted repetitive behaviour. This study aimed at the characterization of a constitutive knock-out (ko) mouse model that carries a deletion of the miR379-410 cluster. Extensive behavioural assays across the animals’ lifespan and cellular examinations of structural and functional properties of synapses were performed. Furthermore, transcriptome sequencing of adult miR379-410 ko hippocampi allowed the validation of potential direct target candidates of the miRNA cluster by using molecular and biochemical approaches. Mice deficient for the miR379-410 cluster displayed an anti-autistic-like phenotype, consisting of hypersocial behaviour, increased ultrasonic vocalizations (USVs) and reduced repetitive behaviour in the absence of cognitive impairments. Further, miR379-410 ko mice presented an anxiety phenotype over the lifespan. Along with the behavioural phenotype, miR379-410 ko mice showed increased excitatory synaptic transmission and spine density accompanied by an elevated expression of ionotropic glutamate receptor complex components in the hippocampus. Several of these components, identified by transcriptome profiling (Cnih2, Src, Prr7 and Dlgap3) could be validated as direct miR379-410 target genes. Taken together, the data obtained in this thesis describe for the first time a negative regulatory role of the miR379-410 cluster in social behaviour and the control of genes associated with excitatory synaptic function. Thus, interfering with miRNAs from the miR379-410 cluster could represent in the future a promising strategy for the treatment of neurodevelopmental disorders characterized by social dysfunction, such as ASD

Broken symmetry and the variation of critical properties in the phase behaviour of supramolecular rhombus tilings

The degree of randomness, or partial order, present in two-dimensional supramolecular arrays of isophthalate tetracarboxylic acids is shown to vary due to subtle chemical changes such as the choice of solvent or small differences in molecular dimensions. This variation may be quantified using an order parameter and reveals a novel phase behaviour including random tiling with varying critical properties as well as ordered phases dominated by either parallel or non-parallel alignment of neighbouring molecules, consistent with long-standing theoretical studies. The balance between order and randomness is driven by small differences in the intermolecular interaction energies, which we show, using numerical simulations, can be related to the measured order parameter. Significant variations occur even when the energy difference is much less than the thermal energy highlighting the delicate balance between entropic and energetic effects in complex self-assembly processes

An evaluation of DNA damage in human lymphocytes and sperm exposed to methyl methanesulfonate involving the regulation pathways associated with apoptosis

YesExposure to DNA-damaging agents produces a range of stress-related responses. These change the expression of genes leading to mutations that cause cell cycle arrest, induction of apoptosis and cancer. We have examined the contribution of haploid and diploid DNA damage and genes involved in the regulation of the apoptotic process associated with exposure, The Comet assay was used to detect DNA damage and quantitative RT-PCR analysis (qPCR) to detect gene expression changes in lymphocytes and sperm in response to methyl methanesulfonate. In the Comet assay, cells were administered 0–1.2 mM of MMS at 37 °C for 30 min for lymphocytes and 32 °C for 60 min for sperm to obtain optimal survival for both cell types. In the Comet assay a significant increase in Olive tail moment (OTM) and % tail DNA indicated DNA damage at increasing concentrations compared to the control group. In the qPCR study, cells were treated for 4 h, and RNA was isolated at the end of the treatment. qPCR analysis of genes associated with DNA stress responses showed that TP53 and CDKN1A are upregulated, while BCL2 is downregulated compared with the control. Thus, MMS caused DNA damage in lymphocytes at increasing concentrations, but appeared not to have the same effect in sperm at the low concentrations. These results indicate that exposure to MMS increased DNA damage and triggered the apoptotic response by activating TP53, CDKN1A and BCL2. These findings of the processing of DNA damage in human lymphocytes and sperm should be taken into account when genotoxic alterations in both cell types are produced when monitoring human exposure.Libyan Governmen

Loss of the miR379-410 cluster in mice leads to alterations in social and anxiety-related behaviours

microRNAs (miRNAs) belong to a group of small non-coding RNAs that down regulates gene expression at the post-transcriptional level. The paternally imprinted placental mammal-specific miR379-410 cluster hosts 38 miRNAs. In the last decade, several members of the cluster have been shown to regulate synapse development and plasticity in mammals. Further, they have been implicated in a variety of diseases, including neurodevelopmental disorders. However, the potential involvement of these miRNAs in the control of complex behaviour in mammals, such as sociability, remains largely unknown. This is an important issue since aberrant synaptic dysfunction is thought to underlie neurodevelopmental diseases, such as autism spectrum disorder (ASD), characterized by deficits in social communication and interaction as well as restricted repetitive behaviour. This study aimed at the characterization of a constitutive knock-out (ko) mouse model that carries a deletion of the miR379-410 cluster. Extensive behavioural assays across the animals’ lifespan and cellular examinations of structural and functional properties of synapses were performed. Furthermore, transcriptome sequencing of adult miR379-410 ko hippocampi allowed the validation of potential direct target candidates of the miRNA cluster by using molecular and biochemical approaches. Mice deficient for the miR379-410 cluster displayed an anti-autistic-like phenotype, consisting of hypersocial behaviour, increased ultrasonic vocalizations (USVs) and reduced repetitive behaviour in the absence of cognitive impairments. Further, miR379-410 ko mice presented an anxiety phenotype over the lifespan. Along with the behavioural phenotype, miR379-410 ko mice showed increased excitatory synaptic transmission and spine density accompanied by an elevated expression of ionotropic glutamate receptor complex components in the hippocampus. Several of these components, identified by transcriptome profiling (Cnih2, Src, Prr7 and Dlgap3) could be validated as direct miR379-410 target genes. Taken together, the data obtained in this thesis describe for the first time a negative regulatory role of the miR379-410 cluster in social behaviour and the control of genes associated with excitatory synaptic function. Thus, interfering with miRNAs from the miR379-410 cluster could represent in the future a promising strategy for the treatment of neurodevelopmental disorders characterized by social dysfunction, such as ASD

Advanced paternal age as a risk factor for neurodevelopmental disorders: a translational study

Advanced paternal age (APA) is a risk factor for several neurodevelopmental disorders, including autism and schizophrenia. The potential mechanisms conferring this risk are poorly understood. Here, we show that the personality traits schizotypy and neuroticism correlated with paternal age in healthy subjects (N = 677). Paternal age was further positively associated with gray matter volume (VBM, N = 342) in the right prefrontal and the right medial temporal cortex. The integrity of fiber tracts (DTI, N = 222) connecting these two areas correlated positively with paternal age. Genome-wide methylation analysis in humans showed differential methylation in APA individuals, linking APA to epigenetic mechanisms. A corresponding phenotype was obtained in our rat model. APA rats displayed social-communication deficits and emitted fewer pro-social ultrasonic vocalizations compared to controls. They further showed repetitive and stereotyped patterns of behavior, together with higher anxiety during early development. At the neurobiological level, microRNAs miR-132 and miR-134 were both differentially regulated in rats and humans depending on APA. This study demonstrates associations between APA and social behaviors across species. They might be driven by changes in the expression of microRNAs and/or epigenetic changes regulating neuronal plasticity, leading to brain morphological changes and fronto-hippocampal connectivity, a network which has been implicated in social interaction

Probing properties of molecule-based interface systems: general discussion and Discussion of the Concluding Remarks

Amabilino D, Bâldea I, Batteas J, et al. Probing properties of molecule-based interface systems: general discussion and Discussion of the Concluding Remarks. Faraday Discussions. 2017;204:503-530