Biology subjects

Yates, S. D.

Publications and source records attributed to Yates, S. D..

4 recordsLinked to original sources

bioRxiv2024

Inhibition of NFAT promotes loss of tissue resident uterine natural killer cells and attendant pregnancy complications in humans

Uterine natural killer cells (uNKs) are a tissue resident lymphocyte population that are critical for pregnancy success. Although mouse models have demonstrated that NK deficiency results in abnormal placentation and poor pregnancy outcomes, the generalizability of this knowledge to humans remains unclear. Here we identify uterus transplant (UTx) recipients as a human population with reduced uNK cells and altered pregnancy phenotypes. We show that the NK reduction in UTx correlates with impaired transcriptional programming of NK tissue residency arising from the inhibition of NFAT-mediated signaling. Our observations suggest that NFAT-dependent genes modulate multiple molecular tissue residency programs in uNKs. These include early residency programs involving AP-1-family transcription factors and TGF-{beta}-mediated upregulation of surface integrins. Collectively, our data identify a previously undescribed role for NFAT in uterine NK tissue residency and provide novel mechanistic insights into the biologic basis of pregnancy complications due to alteration of tissue resident NK subsets in humans. One Sentence SummaryRole of NFAT in uterine NK cell tissue residency

immunology↗

bioRxiv2024

Sequential Transcriptional Programs of Tissue Residency Drive Human Uterine NK Cell Development

Uterine natural killer cells are critical for pregnancy success, but the origin and development of these cells in humans remain unclear. Here we use various single cell approaches to identify the transcriptional programs governing uterine NK cell development in humans. These analyses suggest a developmental continuum which begins with seeding of the endometrium with blood immature CD56bright precursors, evolves through CD56bright endometrial founder NK cells, and ends with tissue resident decidual NK cells during pregnancy which possess non-cytotoxic functions. Our work identifies a role for sequential programs of tissue residency in the differentiation of these cells, as differentiating endometrial tissue resident NK (trNK) cells acquire early and late transcriptional programs of residency which coincide with acquisition of unique non-cytotoxic effector programs. Notably, we identified early residency programs in human endometrial trNKs by expression of NR4A2, AP-1 transcription factors, and other immediate early response genes that were shared with CD8 tissue resident memory T cells in mice, suggesting conservation of transcriptional programs of early tissue residency programs across species and cell types. Late residency programs were guided by TGF{beta}, which promoted expression of various integrins and trNK subset diversification within the non-pregnant endometrium. Altogether, these data identify the molecular foundations for endometrial trNK heterogeneity and suggest that the uterine NK diversity observed during pregnancy is established before embryo implantation and intimately tied to residency programming.

immunology↗

bioRxiv2021

Impaired clock gene expression and abnormal diurnal regulation of hippocampal inhibitory transmission and spatial memory in a mouse model of Alzheimers disease

Patients with Alzheimers disease (AD) often have fragmentation of sleep/wake cycles and disrupted 24-h (circadian) activity. Despite this, little work has investigated the potential underlying day/night disruptions in cognition and neuronal physiology in the hippocampus. The molecular clock, an intrinsic transcription-translation feedback loop that regulates circadian behavior, may also regulate hippocampal neurophysiological activity. We hypothesized that disrupted diurnal variation in clock gene expression in the hippocampus corresponds with loss of normal day/night differences in membrane excitability, synaptic physiology, and cognition. We previously reported that the Tg-SwDI mouse model of AD has disrupted circadian locomotor rhythms and neurophysiological output of the suprachiasmatic nucleus (the primary circadian clock). Here, we report that Tg-SwDI mice failed to show day-night differences in a spatial working memory task, unlike wild-type controls that exhibited enhanced spatial working memory at night. Moreover, Tg-SwDI mice had lower levels of Per2, one of the core components of the molecular clock, at both mRNA and protein levels when compared to age-matched controls. Interestingly, we discovered neurophysiological impairments in area CA1 of the Tg-SwDI hippocampus. In controls, spontaneous inhibitory post-synaptic currents (sIPSCs) in pyramidal cells showed greater amplitude and lower inter-event interval during the day than the night. However, the normal day/night differences in sIPSCs were absent (amplitude) or reversed (inter-event interval) in pyramidal cells from Tg-SwDI mice. In control mice, current injection into CA1 pyramidal cells produced more firing during the night than during the day, but no day/night difference in excitability was observed in Tg-SwDI mice. The normal day/night difference in excitability in controls was blocked by GABA receptor inhibition. Together, these results demonstrate that the normal diurnal regulation of inhibitory transmission in the hippocampus is diminished in a mouse model of AD, leading to decreased daytime inhibition onto hippocampal CA1 pyramidal cells. Uncovering disrupted day/night differences in circadian gene regulation, hippocampal physiology, and memory in AD mouse models may provide insight into possible chronotherapeutic strategies to ameliorate Alzheimers disease symptoms or delay pathological onset.

neuroscience↗

bioRxiv2018

Increased α-2,8-sialyltransferase 8B (ST8SIA2) expression in schizophrenia superior temporal gyrus

Reduced polysialylation of neural cell adhesion molecule (NCAM) in schizophrenia has been suggested to contribute to abnormal neuroplasticity and neurodevelopmental features of this illness. The posttranslational addition of sialic acid is mediated by sialyltransferases, and polysialylation (the addition of [≥] 8 -2,8-linked sialic acid residues) is catalyzed by three enzymes: ST8SIA2 (also called STX), ST8SIA4 (also called PST), and/or ST8SIA3. ST8SIA2 and ST8SIA4 are the primary mediators of NCAM polysialylation. The gene encoding ST8SIA2 maps to schizophrenia risk locus 15q26, and single nucleotide polymorphisms (SNPs) and SNP haplotypes of the ST8SIA2 gene have been associated with schizophrenia in multiple populations. The current study in elderly schizophrenia (N = 16) and comparison (N = 14) subjects measured the protein expression of NCAM, polysialylated-NCAM (PSANCAM), and three poly--2,8-sialyltransferases (ST8SIA2, ST8SIA3, and ST8SIA4) in postmortem superior temporal gyrus. Although expression of NCAM, PSA-NCAM, ST8SIA3, and ST8SIA4 were not different in schizophrenia, increased protein levels of ST8SIA2 were identified. It has been reported that ST8SIA2 mutations associated with increased schizophrenia risk impair PSA-NCAM synthesis, suggesting that increased protein expression of ST8SIA2 may represent a compensatory mechanism in the face of impaired enzyme function. This interpretation is further supported by our finding that the relationship between ST8SIA2 enzyme expression and PSA-NCAM levels are different between schizophrenia and comparison subjects. Together these findings suggest a possible neurodevelopmentally-regulated mechanism which could contribute to abnormal synaptic plasticity evident in schizophrenia.

neuroscience↗