Biology subjects

Garagnani, P.

Publications and source records attributed to Garagnani, P..

6 recordsLinked to original sources

bioRxiv2023

Convergent evolution of complex adaptive traits enabled human life at high altitudes

Convergent adaptations represent paradigmatic examples of the capacity of natural selection to influence organisms biology. However, the possibility to investigate genetic determinants underpinning convergent complex adaptive traits has been offered only recently by methods for inferring polygenic adaptations from genomic data. Relying on this approach, we demonstrate how high-altitude Andean human groups experienced pervasive selective events at angiogenic pathways, which resemble those previously attested for Himalayan populations despite partial convergence at the single-gene level was observed. This provides unprecedented evidence for the drivers of convergent evolution of enhanced blood perfusion in populations exposed to hypobaric hypoxia for thousands of years.

evolutionary biology↗

bioRxiv2023

Increased hippocampal epigenetic age in the Ts65Dn Mouse Model of Down Syndrome

Down syndrome (DS) is a segmental progeroid genetic disorder associated to multi-systemic precocious ageing phenotypes, which are particularly evident at the immune and nervous systems. Accordingly, people with DS show an increased biological age as measured by epigenetic clocks. Ts65Dn trisomic mouse, which harbors extra-numerary copies of Hsa21-syntenic regions, was shown to recapitulate several progeroid features of DS, but no biomarkers of age have been applied to it so far. Here we used a mouse specific epigenetic clock to measure epigenetic age of hippocampi from Ts65Dn and euploid mice at 20 weeks. Ts65Dn mice showed an increased hippocampal epigenetic age respect to controls, and the observed changes in DNA methylation partially recapitulated those observed in hippocampi from people with DS. Collectively, our results support the use of the Ts65Dn model to decipher the molecular mechanisms underlying the progeroid DS phenotypes.

molecular biology↗

bioRxiv2021

Epigenomic signature of the progeroid Cockayne syndrome exposes distinct and common features with physiological ageing

Cockayne syndrome (CS) and UV-sensitivity syndrome (UVSS) are rare genetic disorders caused by mutation of the DNA repair and chromatin remodelling proteins CSA or CSB, but only CS patients display a progeroid and neurodegenerative phenotype. As epigenetic modifications constitute a well-established hallmark of ageing, we characterized genome-wide DNA methylation (DNAm) of fibroblasts from CS versus UVSS patients and healthy donors. The analysis of differentially methylated positions and regions revealed a CS-specific epigenetic signature, enriched in developmental transcription factors, transmembrane transporters, and cell adhesion factors. The CS-specific signature compared to DNAm changes in other progeroid diseases and regular ageing, identifyied commonalities and differences in epigenetic remodelling. CS shares DNAm changes with normal ageing more than other progeroid diseases do, and according to the methylation clock CS samples show up to 13-fold accelerated ageing. Thus, CS is characterized by a specific epigenomic signature that partially overlaps with and exacerbates DNAm changes occurring in physiological aging. Our results unveil new genes and pathways that are potentially relevant for the progeroid/degenerative CS phenotype.

molecular biology↗

bioRxiv2020

DLX5/6 GABAergic expression affects social vocalization: implications for human evolution

DLX5 and DLX6 are two closely related transcription factors involved in brain development and in GABAergic differentiation. The DLX5/6 locus is regulated by FoxP2, a gene involved in language evolution and has been associated to neurodevelopmental disorders and mental retardation. Targeted inactivation of Dlx5/6 in mouse GABAergic neurons (Dlx5/6VgatCre mice) results in behavioural and metabolic phenotypes notably increasing lifespan by 33%. Here, we show that Dlx5/6VgatCre mice present a hyper-vocalization and hyper-socialization phenotype. While only 7% of control mice emitted more than 700 vocalizations/10min, 30% and 56% of heterozygous or homozygous Dlx5/6VgatCre mice emitted more than 700 and up to 1400 calls/10min with a higher proportion of complex and modulated calls. Hyper-vocalizing animals were more sociable: the time spent in dynamic interactions with an unknown visitor was more than doubled compared to low-vocalizing individuals. The characters affected by Dlx5/6 in the mouse (sociability, vocalization, skull and brain shape...) overlap those affected in the "domestication syndrome". We therefore explored the possibility that DLX5/6 played a role in human evolution and "self-domestication" comparing DLX5/6 genomic regions from Neanderthal and modern humans. We identify an introgressed Neanderthal haplotype (DLX5/6-N-Haplotype) present in 12.6% of European individuals that covers DLX5/6 coding and regulatory sequences. The DLX5/6-N-Haplotype includes the binding site for GTF2I, a gene associated to Williams-Beuren syndrome, a hyper-sociability and hyper-vocalization neurodevelopmental disorder. The DLX5/6-N-Haplotype is significantly underrepresented in semi-supercentenarians (>105y of age), a well-established human model of healthy ageing and longevity, suggesting their involvement in the co-evolution of longevity, sociability and speech.

evolutionary biology↗

bioRxiv2020

Complex sex-specific age-related changes in DNA methylation including variability, epimutations and entropy

In humans, females live longer than males but experience a worse longevity, as genome-wide autosomal DNA methylation differences between males and females have been reported. So far, few studies have investigated if DNA methylation is differently affected by aging in males and females. We performed a meta-analysis of 4 large whole blood datasets, comparing 4 aspects of epigenetic age-dependent remodeling between the two sexes: differential methylation, variability, epimutations and entropy. We reported that a large fraction (43%) of sex-associated probes undergoes age-associated DNA methylation changes, and that a limited number of probes shows age-by-sex interaction. We experimentally validated 2 regions mapping in FIGN and PRR4 genes, and showed sex-specific deviations of their methylation patterns in models of decelerated (centenarians) and accelerated (Down syndrome) aging. While we did not find sex differences in the age-associated increase in epimutations and in entropy, we showed that the number of probes showing age-related increase in methylation variability is 15 times higher in males compared to females. Our results can offer new epigenetic tools to study the interaction between aging and sex and can pave the way to the identification of molecular triggers of sex differences in longevity and age-related diseases prevalence.

genomics↗

bioRxiv2018

Comparative analysis of molecular signatures suggests the use of gabapentin for the management of endometriosis-associated pain

CapsuleComparative analysis of gene expression signatures from endometriosis and mouse models shows that CACNA2{delta}s calcium-channel components involved in nociception are targets for the treatment of endometriosis-associated pain.\n\nContextDifferential gene expression analyses comparing endometriotic lesions to eutopic endometrium have shown that the transcription factors DLX5 and DLX6 are drastically down-regulated in the ectopic implants. These finding suggests that regulatory cascades involving DLX5/6 might be involved in the origin of endometriosis symptoms such as chronic pelvic pain. We have shown that mice in which Dlx5 and Dlx6 are selectively inactivated in the uterus present an endometrial phenotype reminiscent of endometriosis implants.\n\nObjectiveIdentify new targets for the treatment of endometriosis.\n\nDesignTo better focus the search for endometriosis targets we have compared the profile of genes deregulated in normal and ectopic women endometrium to those deregulated in the uterus of normal and Dlx5/Dlx6-null mice.\n\nSettingsAcademic research unit and University Hospital research laboratory\n\nAnimalsMice carrying a uterus-specific deletion of Dlx5/Dlx6.\n\nInterventionsAnalysis of archive sections from normal endometrium and endometriosis implants.\n\nMain OutcomeA novel endometriosis signature suggests that 2{delta}s subunits of voltage-gated calcium channel are targets for the management of endometriosis-associated pain.\n\nResultsWe identify a signature of 30 genes similarly deregulated in human endometriosis implants and in Dlx5/6-null mouse uteri reinforcing the notion that the down-regulation of Dlx5/6 is an early event in the progress of endometriosis. CACNA2D3, a component of the voltage-dependent calcium channel complex is strongly overexpressed both in endometriosis implants and in mutant mouse uteri; other members of the alfa2delta family, CACNA2D1 and CACNA2D2, are also overexpressed in endometriosis.\n\nConclusionCACNA2D1, CACNA2D2 and CACNA2D3 are directly involved in pain perception. In particular, CACNA2D3 has been associated to pain sensitization and heat nociception in animal models while, in patients, variants of this gene are associated to reduced sensitivity to acute noxious stimuli. As CACNA2Ds are targets of gabapentinoids analgesics, our results suggest to consider the use of these drugs for the treatment of endometriosis-associated pain. Indeed, recent small-scale clinical studies have shown that gabapentin can be effective in the treatment of women chronic pelvic pain. Our findings reinforce the need for a large definitive trial.

pharmacology and toxicology↗