Biology subjects

Hyttel, P.

Publications and source records attributed to Hyttel, P..

3 recordsLinked to original sources

bioRxiv2020

Characterization of the Endometrial Transcriptome in Early Diestrus Influencing Pregnancy Establishment in Dairy Cattle after Transfer of In-Vitro Produced Embryos

Modifications of the endometrial transcriptome at day 7 of the estrus cycle are crucial to maintain gestation after transfer of in-vitro produced (IVP) embryos. The aim of this study was to identify genes, and their related biological mechanisms, in the endometria of recipient lactating dairy cows that become pregnant in the subsequent estrus cycle upon transfer of IVP embryos. Endometrial biopsies were taken from lactating Holstein Friesian cows on day 6-8 of the estrus cycle followed by embryo transfer in the following cycle. Animals were classified retrospectively as pregnant (PR, n=8) or non-pregnant (non-PR, n=11) cows, according to pregnancy status at 26-47 days. Extracted mRNAs from endometrial samples were sequenced with an Illumina platform to determine differentially expressed genes (DEG) between the endometrial transcriptome from PR and non-PR cows. There were 111 DEG (FDR<0.05), which were mainly related to extracellular matrix interaction, histotroph metabolic composition, prostaglandin synthesis, TGF-{beta} signaling as well as inflammation and leukocyte activation. Comparison of these DEG with DEG identified in two public external datasets confirmed the more fertile endometrial molecular profile of PR cows. In conclusion, this study provides insights into the key early endometrial mechanisms for pregnancy establishment, after IVP embryo transfer in dairy cows.

systems biology↗

bioRxiv2019

Sandwich cortical lamination and single-cell analysis decodes the developing spatial processing system.

Classic studies investigating how and when the entorhinal cortex (component of the memory processing system of the brain) develops have been based on traditional thymidine autoradiography and histological techniques. In this study, we take advantage of modern technologies to trace at a high resolution, the cellular complexity of the developing porcine medial entorhinal cortex by using single-cell profiling. The postnatal medial entorhinal cortex comprises 4 interneuron, 3 pyramidal neuron and 2 stellate cell populations which emerge from intermediate progenitor and immature neuron populations. We discover four MGE-derived interneurons and one CGE-derived interneuron population as well as several IN progenitors. We also identify two oligodendrocyte progenitor populations and three populations of oligodendrocytes. We perform a proof-of-concept experiment demonstrating that porcine scRNA-seq data can be used to develop novel protocols for producing human entorhinal cells in-vitro. We identified six transcription factors (RUNX1A1, SOX5, FOXP1, MEF2C, TCF4, EYA2) important in neurodevelopment and differentiation from one RELN+ stellate cell population. Using a lentiviral vector approach, we reprogrammed human induced pluripotent stem cells into stellate cell-like cells which expressed RELN, SATB2, LEF1 and BCL11B. Our findings contribute to the understanding of the formation of the brains cognitive memory and spatial processing system and provides proof-of-concept for the production of entorhinal cells from human pluripotent stem cells in-vitro.

developmental biology↗

bioRxiv2019

Lysosomal perturbations in dopaminergic neurons derived from induced pluripotent stem cells with PARK2 mutation

Mutations in the PARK2 gene encoding parkin, an E3 ubiquitin ligase, are associated with autosomal recessive early-onset Parkinsons disease (PD). While parkin has been implicated in the regulation of mitophagy and proteasomal degradation, the precise mechanism leading to neurodegeneration in both sporadic and familial PD upon parkin loss-of-function mutations remains unknown. Cultures of isogenic induced pluripotent stem cell (iPSC) lines with and without PARK2 knockout (KO) enable mechanistic studies of the effect of parkin deficiency in human dopaminergic neurons. In the present study, we used such cells to investigate the impact of PARK2 KO on the lysosomal compartment combining different approaches, such as mass spectrometry-based proteomics, electron microscopy (TEM) analysis and functional assays. We discovered a clear link between parkin deficiency and lysosomal alterations. PARK2 KO neurons exhibited a perturbed lysosomal morphology, displaying significantly enlarged and electron-lucent lysosomes as well as an increased total lysosomal content, which was exacerbated by mitochondrial stress. In addition, we found perturbed autophagic flux and decreased lysosomal enzyme activity suggesting an impairment of the autophagy-lysosomal pathway in parkin-deficient cells. Interestingly, activity of the GBA-encoded enzyme, {beta}-glucocerebrosidase, was significantly increased suggesting the existence of a compensatory mechanism. In conclusion, our data provide a unique characterization of the morphology, content, and function of lysosomes in PARK2 KO neurons, thus revealing a new important connection between mitochondrial dysfunction and lysosomal dysregulation in PD pathogenesis.

neuroscience↗