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Mansuy, I. M.

Publications and source records attributed to Mansuy, I. M..

12 recordsLinked to original sources

Paternal diet shapes paternal and maternal transcriptomes in the early embryo through parallel sperm-associated mechanisms

Life experiences in fathers can influence phenotypes in the offspring. While it is known that acquired paternal information can be transferred to descendants via the germline, how such transfer operates between sperm and embryo remains unclear. We examined the effects of low protein diet (LPD) on males of different genotypes and their hybrid offspring generated by reciprocal outcross and on their genome. We found that LPD induces genotype-specific effects in fathers and different phenotypes in their male and female offspring. Allele-specific analyses revealed that paternal LPD modifies paternal and maternal transcriptomes differently in early two-cell embryos. Changes in the paternal transcriptome overlap with the sperm transcriptome and are associated with sperm chromatin features, suggesting that sperm-inherited transcripts and chromatin states may shape the paternal transcriptome in the embryo. The maternal transcriptome, by contrast, is linked to sperm-derived small RNAs, consistent with a possible role of sperm-derived small RNAs in modulating maternal transcript levels in the embryo. Analyses of undifferentiated spermatogonia populations suggest that LPD-induced sperm states can originate from early stages of germ cells. These findings provide evidence that paternal experiences can influence the early embryo via processes involving each parental allele differently.

molecular biology↗

Early life stress affects the transcription and chromatin accessibility of spermatogonial cells

Adversity in early life has lasting effects on the physiology and behavior of exposed individuals and their descendants. In mice, early-life stress alters the RNA content of adult sperm, and this RNA is sufficient to transmit some of the effects to the offspring who were never exposed. However, sperm cells are not yet formed during the early postnatal window in which the exposure occurs. Spermatogonial cells (SPGs), which give rise to them, are present at that time, but whether they respond to the exposure and maintain a molecular signature of it into adulthood is unknown. Here we show that early-life stress alters both the transcriptome and the chromatin accessibility of mouse SPGs, and that a molecular signature of the exposure remains detectable in adulthood. One day after exposure ended, the transcriptional response was extensive, with proliferation and nucleosome-organization programs coordinately up-regulated. In adulthood, the transcriptional response was modest and dominated by coordinately down-regulated gene programs. Single-cell profiling of the whole testis localized the adult response to spermatogonial stem cells (SSCs) and to genes involved in spermatogenesis. At the chromatin level, accessibility shifted one day after exposure at binding motifs for signal-responsive transcription factor families, and in adulthood at a different set of families, in both cases at primed enhancers. These data demonstrate that SPGs respond to an early postnatal environmental exposure and identify them as a candidate origin of the molecular changes later found in adult sperm.

genomics↗

Circulating extracellular vesicles can transport stress signals to the male germline

Extracellular vesicles (EVs) play a key role in cell-cell communication by transporting bioactive molecules from donor to recipient cells across the body. While their involvement in somatic cells communication is well described, somatic-to-germ cells communication remains understudied. We show that small EVs (sEVs) can vehicle signals of early life stress (ELS) from circulation to sperm consequentially for the offspring. In mice, ELS persistently modifies RNA, lipids and metabolites in plasma sEVs. Chronic injection of plasma sEVs from ELS-exposed males alters the sperm transcriptome and is reflected in the transcriptome of embryos. This leads to metabolic dysfunctions in the adult offspring. These findings highlight a role of circulating sEVs in soma-to-germline communication relevant for the intergenerational transmission of ELS effects.

cell biology↗

NanoTag - an IgG-free method for mapping DNA-protein interactions

Genome-wide profiling of DNA-protein interactions in cells can provide important information about mechanisms of gene regulation. Most current methods for genome-wide profiling of DNA-bound proteins, such as ChIP-seq and CUT&Tag, use conventional IgG antibodies to bind target protein(s), which limits their applicability to targets for which high affinity and high specificity antibodies are available. Here we describe NanoTag, a novel method derived from CUT&Tag that is IgG-free and uses a nanobody to profile DNA-protein interactions. NanoTag is based on an anti-GFP nanobody-Tn5 transposase fusion that allows mapping GFP-tagged proteins associated with chromatin in a fast and cost-effective manner. We demonstrate the utility of NanoTag by profiling the histone mark H3K4me3 via its binding partner TATA box-binding protein-associated factor 3 (TAF3) and the transcription factors Nanog and CTCF in mouse embryonic stem cells expressing GFP-tagged targets. For the targets examined, NanoTag data shows high correlation to CUT&Tag data and displays a similarly high signal-to-noise ratio. Overall, NanoTag provides a flexible, IgG-free and cost-effective method to generate high resolution DNA-binding profiles in cells or tissues.

molecular biology↗

Transgenerational effects of early life stress on the fecal microbiota in mice

Stress in early life can affect the progeny and increase the risk to develop psychiatric and cardiometabolic diseases across generations. The cross-generational effects of early life stress have been modeled in mice and demonstrated to be associated with epigenetic factors in the germline. While stress is known to affect gut microbial features, whether its effects can persist across life and be passed to the progeny is not well defined. Here we show that early postnatal stress in mice shifts the fecal microbial composition (binary Jaccard index) throughout life. Further effects on fecal microbial composition and structure (weighted Jaccard index) are detected in the progeny across two generations. These effects are not accompanied by changes in bacterial metabolites and related predicted metabolic pathways in any generation. These results suggest that changes in the fecal microbial community induced by early life traumatic stress can be perpetuated from exposed parent to the offspring.

microbiology↗

Paternal transmission of behavioural and metabolic traits induced by postnatal stress to the 5th generation in mice

Life experiences and environmental conditions in childhood can change the physiology and behaviour of exposed individuals and in some cases, of their offspring. In rodent models, stress/trauma, poor diet and endocrine disruptors in a parent have been shown to cause phenotypes in the direct progeny, suggesting intergenerational inheritance. A few models also examined transmission to further offspring and suggested transgenerational inheritance, but such multi-generations inheritance is not well characterized. Our previous work in a mouse model of early postnatal stress showed that behaviour and metabolism are altered in the offspring of exposed males up to the 4th generation in the patriline and up to the 2nd generation in the matriline. The present study examined if in the patriline, symptoms can be transmitted beyond the 4th generation. Analyses of the 5th and 6th generation of mice revealed that altered risk-taking and glucose regulation caused by postnatal stress are still manifested in the 5th generation but are attenuated in the 6th generation. Some of the symptoms are expressed in both males and females, but some are sex-dependent and sometimes opposite. These results indicate that postnatal trauma can affect behaviour and metabolism over many generations, suggesting epigenetic mechanisms of transmission.

animal behavior and cognition↗

EXPLORE: A novel deep learning-based analysis method for exploration behaviour in object recognition tests

Object recognition tests are widely used in neuroscience to assess memory function in rodents. Despite the experimental simplicity of the task, the interpretation of behavioural features that are counted as object exploration can be complicated. Thus, object exploration is often analysed by manual scoring, which is time-consuming and variable across researchers. Current software using tracking points often lacks precision in capturing complex ethological behaviour. Switching or losing tracking points can bias outcome measures. To overcome these limitations we developed "EXPLORE", a simple, ready-to use and open source pipeline. EXPLORE consists of a convolutional neural network trained in a supervised manner, that extracts features from images and classifies behaviour of rodents near a presented object. EXPLORE achieves human-level accuracy in identifying and scoring exploration behaviour and outperforms commercial software with higher precision, higher versatility and lower time investment, in particular in complex situations. By labeling the respective training data set, users decide by themselves, which types of animal interactions on objects are in- or excluded, ensuring a precise analysis of exploration behaviour. A set of graphical user interfaces (GUIs) provides a beginning-to-end analysis of object recognition tests, accelerating a fast and reproducible data analysis without the need of expertise in programming or deep learning.

animal behavior and cognition↗

Early life stress affects the miRNA cargo in epididymal extracellular vesicles in mouse

Sperm RNA can be modified by environmental factors and has been implicated in communicating signals about changes in a fathers environment to the offspring. The RNA composition of sperm is influenced during its final stage of maturation in the epididymis by extracellular vesicles released by epididymal cells. We studied the effect of exposure to stress in postnatal life on the transcriptome of epididymal extracellular vesicles using a mouse model of transgenerational transmission. We found that the small RNA signature of epididymal extracellular vesicles, particularly miRNAs, is altered in adult males exposed to postnatal stress. miRNAs changes correlate with differences in the expression of their target genes in sperm and zygotes generated from that sperm. These results suggest that stressful experiences in early life can have persistent biological effects on the male reproductive tract that may in part be responsible for the transmission of the effects of exposure to the offspring. Summary SentencemiRNA cargo of extracellular vesicles in cauda epididymis is changed by paternal exposure to early life stress, which correlates with differences in the expression of their target genes in sperm and zygotes generated from that sperm

molecular biology↗

Transcriptome and epigenome characterization of mouse spermatogonial cells reveals distinct chromatin regulatory landscapes in postnatal and adult testis

In mammals, spermatogonial cells (SPGs) are undifferentiated male germ cells in testis that are quiescent until birth and then self-renew and differentiate to produce spermatogenic cells and functional sperm from early postnatal life throughout adulthood. The transcriptome of SPGs is highly dynamic and timely regulated during postnatal development. We examined if such dynamics involves changes in chromatin organization by profiling the transcriptome and chromatin accessibility of SPGs from early postnatal stages to adulthood in mice using deep RNA-seq, ATAC-seq and computational deconvolution analyses. By integrating transcriptomic and epigenomic features, we show that SPGs undergo massive chromatin remodeling during postnatal development that partially correlates with distinct gene expression profiles and transcription factors (TF) motif enrichment. We identify genomic regions with significantly different chromatin accessibility in adult SPGs that are marked by histone modifications associated with enhancers and promoters. Some of the regions with increased accessibility correspond to transposable element subtypes enriched in multiple TFs motifs and close to differentially expressed genes. Our results underscore the dynamics of chromatin organization in developing germ cells and complement existing datasets on SPGs by providing maps of the regulatory genome at high resolution from the same cell populations at early postnatal, late postnatal and adult stages collected from single individuals.

developmental biology↗

Effects of early life stress on bone homeostasis in mice and humans

Bone pathology is frequent in stressed individuals. A comprehensive examination of mechanisms linking life stress, depression and disturbed bone homeostasis is missing. In this translational study, mice exposed to early life stress (MSUS) were examined on bone microarchitecture (CT), metabolism (qPCR), and neuronal stress mediator expression (qPCR) and contrasted with a sample of depressive patients with or without early life stress by analyzing bone mineral density [BMD] (DXA) and metabolic changes in serum (osteocalcin, PINP, CTX-I). MSUS mice showed a significant decrease in NGF, NPYR1, VIPR1 and TACR1 expression, higher innervation density in bone and increased serum levels of CTX-I, suggesting a milieu in favor of catabolic bone turnover. MSUS mice had a significantly lower body weight compared to control mice, and this caused minor effects on bone micro-CT. Depressive patients with experiences of childhood neglect also showed a catabolic pattern. A significant reduction in BMD was observed in depressive patients with childhood abuse and stressful life events during childhood. Therefore, future studies on prevention and treatment strategies for both mental and bone disease should consider early life stress as a risk factor for bone pathologies.

physiology↗

A novel mode of communication between blood and the germline for the inheritance of paternal experiences

In many species, environmental stimuli can affect the germline and contribute to phenotypic changes in the offspring, without altering the genetic code1-5. So far, little is known about which biological signals can link exposure to germ cells. Using a mouse model of postnatal trauma with transgenerational effects, we show that exposure alters lipid-based metabolites in blood of males and their non-exposed offspring. Comparable alterations are validated in serum and saliva of orphan children exposed to trauma. Peroxisome proliferator-activated receptor (PPAR) is identified as mediating the effects of metabolites alterations. Mimicking PPAR activation with a dual PPAR/{gamma} agonist in vivo induces changes in the sperm transcriptome similarly to trauma, and reproduces metabolic phenotypes in the offspring. Injecting serum collected from adult males exposed to postnatal trauma into controls recapitulates metabolic phenotypes in the offspring. These results suggest conserved effects of early life adversity on blood metabolites, and causally involve paternal blood factors and PPAR nuclear receptor in phenotype heritability.

molecular biology↗

Alterations in sperm long RNA contribute to the epigenetic inheritance of the effects of postnatal trauma

Psychiatric diseases have a strong heritable component known to not be restricted to DNA sequence-based genetic inheritance alone but to also involve epigenetic factors in germ cells 1,2. Initial evidence suggested that sperm RNA is causally linked 2,3 to the transmission of symptoms induced by traumatic experiences. Here we show that alterations in long RNA in sperm contribute to the inheritance of specific trauma symptoms. Injection of long RNA fraction from sperm of males exposed to postnatal trauma recapitulates the effects on food intake, glucose response to insulin and risk-taking in adulthood whereas the small RNA fraction alters body weight and behavioral despair. Alterations in long RNA are maintained after fertilization, suggesting a direct link between sperm and embryo RNA.

developmental biology↗