Temporal Changes In Expression Research Articles

Dynamic changes in human single-cell transcriptional signatures during fatal sepsis.

Systemic infections, especially in patients with chronic diseases, may result in sepsis: an explosive, uncoordinated immune response that can lead to multisystem organ failure with a high mortality rate. Patients with similar clinical phenotypes or sepsis biomarker expression upon diagnosis may have different outcomes, suggesting that the dynamics of sepsis is critical in disease progression. A within-subject study of patients with Gram-negative bacterial sepsis with surviving and fatal outcomes was designed and single-cell transcriptomic analyses of peripheral blood mononuclear cells (PBMC) collected during the critical period between sepsis diagnosis and 6h were performed. The single-cell observations in the study are consistent with trends from public datasets but also identify dynamic effects in individual cell subsets that change within hours. It is shown that platelet and erythroid precursor responses are drivers of fatal sepsis, with transcriptional signatures that are shared with severe COVID-19 disease. It is also shown that hypoxic stress is a driving factor in immune and metabolic dysfunction of monocytes and erythroid precursors. Last, the data support CD52 as a prognostic biomarker and therapeutic target for sepsis as its expression dynamically increases in lymphocytes and correlates with improved sepsis outcomes. In conclusion, this study describes the first single-cell study that analyzed short-term temporal changes in the immune cell populations and their characteristics in surviving or fatal sepsis. Tracking temporal expression changes in specific cell types could lead to more accurate predictions of sepsis outcomes and identify molecular biomarkers and pathways that could be therapeutically controlled to improve the sepsis trajectory toward better outcomes.

OTHER NMDs: EP.350 A study of LINC complex proteins reveals temporal emerin and SUN2 expression changes during myoblast differentiation

Mutations in nuclear envelope (NE) proteins, emerin, lamin A/C, nesprin-1/2 and SUN1/SUN2 have been identified in the causation of Emery-Dreifuss muscular dystrophy (EDMD) and some extremely rare forms of congenital muscular dystrophy (CMD). These NE proteins are all components of the linker of nucleoskeleton and cytoskeleton (LINC) complex, a structure that spans the NE and connects the nuclear lamina (NL) to the cytoskeleton. Some progress has been made to understand the molecular pathways acting downstream of the defective genes, however the roles of these proteins during myoblast development and differentiation are still not fully understood.

P–288 Changes in gene and protein expression in human endometrial cancer cell lines after low dose metformin treatment over time

Abstract Study question Does metformin treatment lead to temporal expression changes of specific genes and proteins in endometrial cancer cell lines? Summary answer The expression of three different genes and proteins was investigated, of which all displayed changes over time. What is known already Endometrial cancer (EC) is one of the most common malignancies among postmenopausal women. A long-term estrogen effect on the endometrium often seen in women with obesity or the polycystic ovary syndrome (PCOS), as well as type II diabetes mellitus (T2DM) are well-known risk factors for the development and progression of EC. Metformin is a biguanide used in the treatment of T2DM patients and off label in women with PCOS. Moreover, metformin displays anti-tumor and anti-proliferative effects in various cancer types, including EC. In that regards BCL2L11, CDH1 and CDKN1A play an important role in apoptotic pathways, proliferation and invasion processes. Study design, size, duration The EC cells were cultured in normal (5.5 mmol/L) or high (17 mmol/L) glucose medium supplemented with 10 nmol/L ß-estradiol. The cells were treated with low dose metformin (1.0 mmol/L) for 2, 6, 24, 48 and 168 h (7 d). In addition, EC cells were treated with a combination of metformin and insulin (100 ng/mL) or remained untreated. Five independent experiments were fulfilled and untreated cells served as controls. Participants/materials, setting, methods The study was accomplished using two different human EC cell lines. HEC–1A represents an estrogen-independent EC, whereas Ishikawa represents the more common, estrogen-dependent EC. Proteins were extracted, quantified with a BCA assay, and the protein expression of BCL2L11, CDH1 and CDKN1A was analyzed by western blots. Furthermore, total RNA was extracted, transcribed to cDNA and Taqman real-time PCR was carried out to measure the expression of the associated genes, using fold change (FC) as parameter. Main results and the role of chance The expression of the selected genes, analyzed by RT-PCR, changed in both cell lines over time as follows: After 6 h, metformin induced a decrease in the expression of BCL2L11 (FC = 0.7) and CDH1 (FC = 0.75), whereas the expression of CDKN1A slightly increased (FC = 0.95–1.35). After 24 h, BCL2L11 expression increased in normal glucose groups (FC = 1.3, high glucose: FC = 0.93) and CDH1 expression decreased in combination with metformin and high glucose (FC = 0.7, normal glucose: FC = 1.1). CDKN1A expression was increased by metformin in both cell lines after 24 h (FC = 1.2–1.8). After 48 h of metformin treatment, expression for all three genes was only slightly changed (FC = 0.9–1.0). After 7 d it was observed that the combination of high glucose and metformin (i.e. like obese T2DM patients) led to an increased expression of BCL2L11, CDH1 and CDKN1A (FC = 1.4–2.9) in the presence and absence of insulin, whereas metformin induced a decreased expression of CDH1 and CDKN1A (FC = 0.5–0.75) in normal glucose medium. BCL2L11, CDH1 and CDKN1A expression was investigated at the protein level as well. Limitations, reasons for caution The results cannot be directly transferred to metformin treatment of patients, since the study was carried out in vitro. Additionally, further studies including more timepoints would indicate a more precisely gene and protein expression over time. Wider implications of the findings: This is the first in vitro study showing the temporal changes of BCL2L11, CDH1 and CDKN1A expression, genes related to tumorigenesis due to low dose metformin over time, suggesting differentially pathways in long term metformin treatment using physiologically achievable metformin levels. Trial registration number Not applicable

The Role of BDNF in Experimental and Clinical Traumatic Brain Injury.

Traumatic brain injury is one of the leading causes of mortality and morbidity in the world with no current pharmacological treatment. The role of BDNF in neural repair and regeneration is well established and has also been the focus of TBI research. Here, we review experimental animal models assessing BDNF expression following injury as well as clinical studies in humans including the role of BDNF polymorphism in TBI. There is a large heterogeneity in experimental setups and hence the results with different regional and temporal changes in BDNF expression. Several studies have also assessed different interventions to affect the BDNF expression following injury. Clinical studies highlight the importance of BDNF polymorphism in the outcome and indicate a protective role of BDNF polymorphism following injury. Considering the possibility of affecting the BDNF pathway with available substances, we discuss future studies using transgenic mice as well as iPSC in order to understand the underlying mechanism of BDNF polymorphism in TBI and develop a possible pharmacological treatment.

The Making of Long-Lasting Memories: A Fruit Fly Perspective

Understanding the nature of the molecular mechanisms underlying memory formation, consolidation, and forgetting are some of the fascinating questions in modern neuroscience. The encoding, stabilization and elimination of memories, rely on the structural reorganization of synapses. These changes will enable the facilitation or depression of neural activity in response to the acquisition of new information. In other words, these changes affect the weight of specific nodes within a neural network. We know that these plastic reorganizations require de novo protein synthesis in the context of Long-term memory (LTM). This process depends on neural activity triggered by the learned experience. The use of model organisms like Drosophila melanogaster has been proven essential for advancing our knowledge in the field of neuroscience. Flies offer an optimal combination of a more straightforward nervous system, composed of a limited number of cells, and while still displaying complex behaviors. Studies in Drosophila neuroscience, which expanded over several decades, have been critical for understanding the cellular and molecular mechanisms leading to the synaptic and behavioral plasticity occurring in the context of learning and memory. This is possible thanks to sophisticated technical approaches that enable precise control of gene expression in the fruit fly as well as neural manipulation, like chemogenetics, thermogenetics, or optogenetics. The search for the identity of genes expressed as a result of memory acquisition has been an active interest since the origins of behavioral genetics. From screenings of more or less specific candidates to broader studies based on transcriptome analysis, our understanding of the genetic control behind LTM has expanded exponentially in the past years. Here we review recent literature regarding how the formation of memories induces a rapid, extensive and, in many cases, transient wave of transcriptional activity. After a consolidation period, transcriptome changes seem more stable and likely represent the synthesis of new proteins. The complexity of the circuitry involved in memory formation and consolidation is such that there are localized changes in neural activity, both regarding temporal dynamics and the nature of neurons and subcellular locations affected, hence inducing specific temporal and localized changes in protein expression. Different types of neurons are recruited at different times into memory traces. In LTM, the synthesis of new proteins is required in specific subsets of cells. This de novo translation can take place in the somatic cytoplasm and/or locally in distinct zones of compartmentalized synaptic activity, depending on the nature of the proteins and the plasticity-inducing processes that occur. We will also review recent advances in understanding how localized changes are confined to the relevant synapse. These recent studies have led to exciting discoveries regarding proteins that were not previously involved in learning and memory processes. This invaluable information will lead to future functional studies on the roles that hundreds of new molecular actors play in modulating neural activity.

Mapping immune variation and var gene switching in naive hosts infected with Plasmodium falciparum.

Falciparum malaria is clinically heterogeneous and the relative contribution of parasite and host in shaping disease severity remains unclear. We explored the interaction between inflammation and parasite variant surface antigen (VSA) expression, asking whether this relationship underpins the variation observed in controlled human malaria infection (CHMI). We uncovered marked heterogeneity in the host response to blood challenge; some volunteers remained quiescent, others triggered interferon-stimulated inflammation and some showed transcriptional evidence of myeloid cell suppression. Significantly, only inflammatory volunteers experienced hallmark symptoms of malaria. When we tracked temporal changes in parasite VSA expression to ask whether variants associated with severe disease rapidly expand in naive hosts, we found no transcriptional evidence to support this hypothesis. These data indicate that parasite variants that dominate severe malaria do not have an intrinsic growth or survival advantage; instead, they presumably rely upon infection-induced changes in their within-host environment for selection.

Abstract P430: Inflammatory Survival Gene Expression Patterns Differentiate Favorable and Unfavorable Outcomes Following Surgical Intervention in Intracerebral Hemorrhage

Background and Aims: Surgical management of intracerebral (ICH) remains controversial due to unclear benefit. In this study, we analyzed temporal changes in expression of proinflammatory and anti-inflammatory survival genes to discern the molecular differences between favorable and unfavorable outcomes after surgery. Methods: Venous blood collected in Paxgene Blood RNA from ICH patients before surgery at ‘early’ (Day 0-2) and at ‘delayed’ (Day 3-5) timepoints. Extracted total RNA was used for real-time Taqman PCR analysis for anti-inflammatory, survival genes superoxide dismutase 1(SOD1), COX-2, IL-10, peroxisome proliferator activated receptor gamma (PPARG), TGF-B1, and IL-10. The pro-inflammatory genes included arginase-1 (ARG1), TNF, IL-1B, monocyte/macrophage activity markers (CD36, CD163) and NF-kB members (NFKB1, NFKB2, RELA, RELB, REL, NFKBIA). Relative fold changes were determined after normalizing to GAPDH. 90-day Modified Rankin Score (mRS) were collected and classified as favorable, mRS 0-3 (n=4) and unfavorable, mRS 4-6 (n=8). Statistical analysis was carried out by Welch’s ANOVA test (p<0.05). Results: Mean age was 56.25yrs (SD 19.7). ICH location was 10 deep nuclei (thalamus or basal ganglia), 1 cerebellum, and 1 lobar. ICH volume was lower in the mRS 0-3 group (24.15ml SD21.2 vs 35.8ml SD 31.7 p=0.68). All patients had a decompressive hemicraniectomy and 7 included hematoma evacuation. Overall, the NFkB family gene expression was increased at ‘delayed’ relative to the early time points in both groups. However, RELB expression was significantly higher at the early time point of mRS 0-3 compared to mRS 4-6 group. Expression of ARG1, SOD1, COX2, IL-1B, IL-10, TGF-B1, PPARG and CD36 increased significantly at the delayed compared to the early time point. In the unfavorable outcome group (mRS 4-6), TNF expression increased significantly at the delayed timepoints compared to mRS 0-3 which was unchanged. Conclusions: The studied genes were highly expressed and differed significantly between time points. TNF was significantly expressed at the delayed time point in the mRS 4-6 group but unchanged in the mRS 0-3 group. Further studies will explore the role of TNF and related genes in patient selection and outcomes for surgical management of ICH.

Abstract P51: Temporal Changes In Nitric Oxide Synthase Isoform Expression And Function In Spontaneously Hypertensive Stroke Prone Rats

Introduction: Nitric oxide (NO) has been implicated in the pathogenesis of cerebral small vessel disease (cSVD). NO is produced by three NO synthase (NOS) isoforms including endothelial (eNOS), neuronal (nNOS), and inducible (iNOS). While eNOS has been implicated in cSVD pathologies that occur in Spontaneously Hypertensive Stroke Prone Rats (SHRSP), cSVD model, the mechanistic role and temporal changes of NOS isoform expression including eNOS in relation to cSVD development in SHRSP remains unknown. We aimed to characterize the temporal changes of NOS isoforms expression in SHRSP from the asymptomatic stage until the development of cSVD lesions. Methods: 20 SHRSP and 20 Wistar Kyoto (WKY) male rats were studied. Systolic blood pressure (SBP) was measured weekly using tail-cuff plethysmography. Half of the groups were euthanized at 7 weeks of age and the remaining rats were followed until 24 weeks of age. Routine histology and immunohistochemistry were performed for eNOS, nNOS, iNOS, superoxide radicals (DHE), NO (DAF) and Iba1 for microglia activation. Results: At 7 weeks, SBP was not significantly different between the groups (WKY 106.6±5.4 vs SHRSP 120.8±5.4, P=0.06). SHRSP developed hypertension between 9-11 weeks and maintained it throughout the experiment (SBP (21 weeks): WKY 134.8±5.4 vs 168.9±5.4, P<0.0001). Brain histology was largely negative for cSVD lesions at 7 weeks. At 24 weeks, histology showed areas of demyelination, microbleed formation, arteriosclerosis and hemosiderin deposits in SHRSP. At 7 weeks, compared to WKY, eNOS and nNOS expression were 50% and 30% lower in SHRSP (P=0.0038 and 0.0211, respectively). iNOS expression was 93% higher in SHRSP (P=0.0068). Superoxide levels were 133% higher in SHRSP (P<0.0001) and NO was 40% lower in SHRSP (P<0.0008). At 24 weeks, all of these differences became larger. Iba-1 expression was 25% higher at 7 weeks and became 97% higher in SHRSP at 24 weeks (P<0.0001). Conclusions: SHRSP show significant differences in NOS isoform expression with loss of NO and gain of superoxide production early in life prior to development of cSVD lesions. Superoxide overproduction and related oxidant stress may lead to NOS dysfunction and uncoupling which may trigger cSVD onset and point towards potential future therapies.

Response of the thyroid axis and appetite-regulating peptides to fasting and overfeeding in goldfish (Carassius auratus)

The thyroid axis is a major regulator of metabolism and energy homeostasis in vertebrates. There is conclusive evidence in mammals for the involvement of the thyroid axis in the regulation of food intake, but in fish, this link is unclear. In order to assess the effects of nutritional status on the thyroid axis in goldfish, Carassius auratus, we examined brain and peripheral transcripts of genes associated with the thyroid axis [thyrotropin-releasing hormone (TRH), thyrotropin-releasing hormone receptors (TRH-R type 1 and 2), thyroid stimulating hormone beta (TSHβ), deiodinase enzymes (DIO2, DIO3) and UDP-glucoronsyltransferase (UGT)] and appetite regulators [neuropeptide Y (NPY), proopiomelanocortin (POMC), agouti-related peptide (AgRP) and cholecystokinin (CCK)] in fasted and overfed fish for 7 and 14 day periods. We show that the thyroid axis responds to overfeeding, with an increase of brain TRH and TSHβ mRNA expression after 14 days, suggesting that overfeeding might activate the thyroid axis. In fasted fish, hepatic DIO3 and UGT transcripts were downregulated from 7 to 14 days, suggesting a time-dependent inhibition of thyroid hormone degradation pathways. Nutritional status had no effect on circulating levels of thyroid hormone. Central appetite-regulating peptides exhibited temporal changes in mRNA expression, with decreased expression of the appetite-inhibiting peptide POMC from 7 to 14 days for both fasted and overfed fish, with no change in central NPY or AgRP, or intestinal CCK transcript expression. Compared to control fish, fasting increased AgRP mRNA expression at both 7 and 14 days, and POMC expression was higher than controls only at 7 days. Our results indicate that nutritional status time-dependently affects the thyroid axis and appetite regulators, although no clear correlation between thyroid physiology and appetite regulators could be established. Our study helps to fill a knowledge gap in current fish endocrinological research on the effects of energy balance on thyroid metabolism and function.

Molecular characterization, expression and functional analysis of acyl-CoA-binding protein gene family in maize (Zea mays)

BackgroundAcyl-CoA-binding proteins (ACBPs) possess a conserved acyl-CoA-binding (ACB) domain that facilitates binding to acyl-CoA esters and trafficking in eukaryotic cells. Although the various functions of ACBP have been characterized in several plant species, their structure, molecular evolution, expression profile, and function have not been fully elucidated in Zea mays L.ResultsGenome-wide analysis identified nine ZmACBP genes in Z. mays, which could be divided into four distinct classes (class I, class II, class III, and class IV) via construction of a phylogenetic tree that included 48 ACBP genes from six different plant species. Transient expression of a ZmACBP-GFP fusion protein in tobacco (Nicotiana tabacum) epidermal cells revealed that ZmACBPs localized to multiple different locations. Analyses of expression profiles revealed that ZmACBPs exhibited temporal and spatial expression changes during abiotic and biotic stresses. Eight of the nine ZmACBP genes were also found to have significant association with agronomic traits in a panel of 500 maize inbred lines. The heterologous constitutive expression of ZmACBP1 and ZmACBP3 in Arabidopsis enhanced the resistance of these plants to salinity and drought stress, possibly through alterations in the level of lipid metabolic and stress-responsive genes.ConclusionThe ACBP gene family was highly conserved across different plant species. ZmACBP genes had clear tissue and organ expression specificity and were responsive to both biotic and abiotic stresses, suggesting their roles in plant growth and stress resistance.

Temporal changes in Egr-1 and c-fos expression in rat models of myocardial ischemia.

The pathological diagnosis of sudden cardiac death caused by myocardial ischemia is a difficult problem. Relevant evidence shows that the expression of Egr-1 and c-fos undergo changes in the early stage of myocardial ischemia, but the detailed temporal variation of them is not clear. Therefore, the aim of this study was to observe the temporal changes in mRNA and protein expression of Egr-1 and c-fos in ischemic myocardium in rats. Sixty-six Sprague-Dawley rats were divided into the control group, the early myocardial ischemia (EMI) group, the sham operated group and the allergy group. The EMI rats were further divided into eight subgroups according to the different time points (30 min and 1, 2, 4, 8, 12, 24, and 48 h) after modeling. The mRNA and protein of Egr-1 and c-fos of each group were detected by real-time quantitative polymerase chain reaction and immunohistochemistry, respectively. In the EMI group, Egr-1 mRNA in ischemic myocardium rose 30 min after ischemia and peaked at 2 h; the plateau was maintained up to 8 h after ischemia, and then returned to the baseline level at 12 h. The c-fos mRNA in ischemic myocardium demonstrated a consistent changing curve with that of Egr-1. The mRNA of Egr-1 and c-fos showed no significant changes in the control group, the sham operated group and the allergy group. Immunohistochemistry showed that Egr-1 protein in the myocardial ischemic area was slightly positive 30 min after ischemia, and then strongly positive at 4 and 8 h, decreased at 12 h, and was negative at 24 h. The changing trends of c-fos protein were almost the same as that of Egr-1. Immunohistochemistry of Egr-1 and c-fos protein were all negative in the control group, the sham operated group and the allergy group. The mRNA and protein expression of Egr-1 and c-fos presented rapid and temporal changes after myocardial ischemia, and this may be helpful in distinguishing sudden death induced by myocardial ischemia from that of allergy.

Temporal changes in DNA methylation and RNA expression in a small song bird: within- and between-tissue comparisons

BackgroundDNA methylation is likely a key mechanism regulating changes in gene transcription in traits that show temporal fluctuations in response to environmental conditions. To understand the transcriptional role of DNA methylation we need simultaneous within-individual assessment of methylation changes and gene expression changes over time. Within-individual repeated sampling of tissues, which are essential for trait expression is, however, unfeasible (e.g. specific brain regions, liver and ovary for reproductive timing). Here, we explore to what extend between-individual changes in DNA methylation in a tissue accessible for repeated sampling (red blood cells (RBCs)) reflect such patterns in a tissue unavailable for repeated sampling (liver) and how these DNA methylation patterns are associated with gene expression in such inaccessible tissues (hypothalamus, ovary and liver). For this, 18 great tit (Parus major) females were sacrificed at three time points (n = 6 per time point) throughout the pre-laying and egg-laying period and their blood, hypothalamus, ovary and liver were sampled.ResultsWe simultaneously assessed DNA methylation changes (via reduced representation bisulfite sequencing) and changes in gene expression (via RNA-seq and qPCR) over time. In general, we found a positive correlation between changes in CpG site methylation in RBCs and liver across timepoints. For CpG sites in close proximity to the transcription start site, an increase in RBC methylation over time was associated with a decrease in the expression of the associated gene in the ovary. In contrast, no such association with gene expression was found for CpG site methylation within the gene body or the 10 kb up- and downstream regions adjacent to the gene body.ConclusionTemporal changes in DNA methylation are largely tissue-general, indicating that changes in RBC methylation can reflect changes in DNA methylation in other, often less accessible, tissues such as the liver in our case. However, associations between temporal changes in DNA methylation with changes in gene expression are mostly tissue- and genomic location-dependent. The observation that temporal changes in DNA methylation within RBCs can relate to changes in gene expression in less accessible tissues is important for a better understanding of how environmental conditions shape traits that temporally change in expression in wild populations.

Proteome Landscape of Epithelial-to-Mesenchymal Transition (EMT) of Retinal Pigment Epithelium Shares Commonalities With Malignancy-Associated EMT

Stress and injury to the retinal pigment epithelium (RPE) often lead to dedifferentiation and epithelial-to-mesenchymal transition (EMT). These processes have been implicated in several retinal diseases, including proliferative vitreoretinopathy, diabetic retinopathy, and age-related macular degeneration. Despite the importance of RPE-EMT and the large body of data characterizing malignancy-related EMT, comprehensive proteomic studies to define the protein changes and pathways underlying RPE-EMT have not been reported. This study sought to investigate the temporal protein expression changes that occur in a human-induced pluripotent stem cell–based RPE-EMT model. We utilized multiplexed isobaric tandem mass tag labeling followed by high-resolution tandem MS for precise and in-depth quantification of the RPE-EMT proteome. We have identified and quantified 7937 protein groups in our tandem mass tag–based MS analysis. We observed a total of 532 proteins that are differentially regulated during RPE-EMT. Furthermore, we integrated our proteomic data with prior transcriptomic (RNA-Seq) data to provide additional insights into RPE-EMT mechanisms. To validate these results, we have performed a label-free single-shot data-independent acquisition MS study. Our integrated analysis indicates both the commonality and uniqueness of RPE-EMT compared with malignancy-associated EMT. Our comparative analysis also revealed that multiple age-related macular degeneration–associated risk factors are differentially regulated during RPE-EMT. Together, our integrated dataset provides a comprehensive RPE-EMT atlas and resource for understanding the molecular signaling events and associated biological pathways that underlie RPE-EMT onset. This resource has already facilitated the identification of chemical modulators that could inhibit RPE-EMT, and it will hopefully aid in ongoing efforts to develop EMT inhibition as an approach for the treatment of retinal disease.

Spatial and Temporal Changes in PD-L1 Expression in Cancer: The Role of Genetic Drivers, Tumor Microenvironment and Resistance to Therapy.

Immunotherapies blocking immune inhibitory receptors programmed cell death-1 (PD-1) and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) on T-cells have dramatically improved patient outcomes in a range of advanced cancers. However, the lack of response, and the development of resistance remain major obstacles to long-term improvements in patient outcomes. There is significant interest in the clinical use of biomarkers to improve patient selection, and the expression of PD-1 ligand 1 (PD-L1) is often reported as a potential biomarker of response. However, accumulating evidence suggests that the predictive value of PD-L1 expression in tumor biopsies is relatively low due, in part, to its complex biology. In this review, we discuss the biological consequences of PD-L1 expression by various cell types within the tumor microenvironment, and the complex mechanisms that regulate PD-L1 expression at the genomic, transcriptomic and proteomic levels.

Sepsis Induces Deregulation of IL-13 Production and PD-1 Expression in Lung Group 2 Innate Lymphoid Cells.

Deregulation of the immune system in sepsis plays the central role in the pathogenesis of multiple organ failure including septic lung injury. Group 2 innate lymphoid cells (ILC2s) have emerged as a new player in regulating immune homeostasis in the lung; however, the role of ILC2s in lung injury in sepsis remains poorly understood. Here, we investigated temporal changes in stimulatory and inhibitory receptor expression and intracellular type 2 cytokine expression of ILC2s in the lung using a cecal ligation and puncture mouse sepsis model. We found that IL-13 production by ILC2s, which were predominately composed of the resident natural ILC2 subset rather than the migratory inflammatory ILC2 subset, was reduced in the lungs of sepsis mice on day 1 and gradually restored through day 7. Although the expression levels of ST2 and inducible T-cell costimulator (stimulatory receptors) were high, IL-13 production by ILC2s was reduced while showing high programmed cell death 1 (PD-1) (inhibitory receptor) expression. Furthermore, using IL-33 knockout mice, we have shown that IL-33 regulates the capacity of ILC2s to produce IL-13, possibly through the modulation of ST2 and PD-1 expression and signaling in the septic lung. To the best of our knowledge, this is the first report showing differential costimulatory/inhibitory receptor expression on ILC2s in a septic lung in the context of an IL-33/IL-13 pathway-mediated type 2 immune response in the progression and resolution of inflammation. Our present findings contribute to a better understanding of the underlying immunological mechanism of ILC2s and may fill the critical knowledge gap regarding immune homeostasis in the lung that hampers the development of new therapeutic strategies for sepsis-induced acute lung injury.

Analysis of Virus and Host Proteomes During Productive HSV-1 and VZV Infection in Human Epithelial Cells.

Herpes simplex virus 1 (HSV-1) and varicella-zoster virus (VZV) are two closely related human alphaherpesviruses that persistently infect most adults worldwide and cause a variety of clinically important diseases. Herpesviruses are extremely well adapted to their hosts and interact broadly with cellular proteins to regulate virus replication and spread. However, it is incompletely understood how HSV-1 and VZV interact with the host proteome during productive infection. This study determined the temporal changes in virus and host protein expression during productive HSV-1 and VZV infection in the same cell type. Results demonstrated the temporally coordinated expression of HSV-1 and VZV proteins in infected cells. Analysis of the host proteomes showed that both viruses affected extracellular matrix composition, transcription, RNA processing and cell division. Moreover, the prominent role of epidermal growth factor receptor (EGFR) signaling during productive HSV-1 and VZV infection was identified. Stimulation and inhibition of EGFR leads to increased and decreased virus replication, respectively. Collectively, the comparative temporal analysis of viral and host proteomes in productively HSV-1 and VZV-infected cells provides a valuable resource for future studies aimed to identify target(s) for antiviral therapy development.

MON-725 Transcriptome Profiling in Postnatal Pituitary Gland Identifies Cell Type-Driven Sex-Specific Changes

The pituitary gland is integral to the regulation of growth, metabolism, puberty, reproduction, and stress responses. Previously, we found that many genes associated with age-at-menarche in genome-wide association studies (GWAS) displayed increasingly sex-biased expression across the pubertal transition in the mouse pituitary. However, whether this trend exists beyond puberty-related genes was not known. In addition, the regulatory mechanisms underlying these gene expression changes remained to be explored. To answer these questions, we profiled the transcriptome, including microRNAs, of mouse pituitary in both sexes across pubertal transition in an unbiased manner and leveraged a recently published pituitary single cell transcriptome to explore cellular composition changes. We found that the most dynamic temporal changes in both mRNA and miRNA expression occur prior to puberty, underscoring a role for regulation of early pituitary postnatal development. We also observed ~900 genes displaying sex-biased expression patterns, arising during early development and becoming increasingly biased across puberty, including known sex-biased genes such as Fshb and Lhb. However, sex differences in miRNA expression are less pronounced, only 13 miRNAs were found to be sex-biased, suggesting lesser contribution of miRNAs to sex-biased gene expression relative to other forms of regulation. To assess whether pituitary cellular composition could underlie changes in gene expression across pubertal transition, we performed single cell deconvolution of our bulk pituitary gland gene expression. Interestingly, we found that sex differences in cell proportions were estimated to emerge across puberty: a greater proportion of lactotropes was found among females, and greater proportions of gonadotropes and somatotropes were found among males. We observed sex-biased expression patterns of marker genes for these cell types, including Prl, Fshb, and Gh. This finding suggests that cell proportion differences between sexes likely contribute to whole pituitary transcriptome changes we observed, however, to what extent remains to be studied. Together our study indicates that miRNAs play a substantial role in regulation of pituitary postnatal development but that differences in cellular composition may contribute more robustly to sex-biased gene expression.

Time-series expression profiling of sugarcane leaves infected with Puccinia kuehnii reveals an ineffective defense system leading to susceptibility.

Successful orange rust development on sugarcane can potentially be explained as suppression of the plant immune system by the pathogen or delayed plant signaling to trigger defense responses. Puccinia kuehnii is an obligate biotrophic fungus that infects sugarcane leaves causing a disease called orange rust. It spread out to other countries resulting in reduction of crop yield since its first outbreak. One of the knowledge gaps of that pathosystem is to understand the molecular mechanisms altered in susceptible plants by this biotic stress. Here, we investigated the changes in temporal expression of transcripts in pathways associated with the immune system. To achieve this purpose, we used RNA-Seq to analyze infected leaf samples collected at five time points after inoculation. Differential expression analyses of adjacent time points revealed substantial changes at 12, 48h after inoculation and 12days after inoculation, coinciding with the events of spore germination, haustoria post-penetration and post-sporulation, respectively. During the first 24h, a lack of transcripts involved with resistance mechanisms was revealed by underrepresentation of hypersensitive and defense response related genes. However, two days after inoculation, upregulation of genes involved with immune response regulation provided evidence of some potential defense response. Events related to biotic stress responses were predominantly downregulated in the initial time points, but expression was later restored to basal levels. Genes involved in carbohydrate metabolism showed evidence of repression followed by upregulation, possibly to ensure the pathogen nutritional requirements were met. Our results support the hypothesis that P. kuehnii initially suppressed sugarcane genes involved in plant defense systems. Late overexpression of specific regulatory pathways also suggests the possibility of an inefficient recognition system by a susceptible sugarcane genotype.

The Regulation of Heme Metabolism in Myocytes by Hypoxia and Ischemia: Substrate‐Enzyme Dyssynchrony

Current strategies for the treatment of acute myocardial infarction (AMI) are limited therefore better pharmacological interventions are needed to improve cardiac function post‐injury. Overexpression of the enzyme heme oxygenase‐1 (HMOX1) has been shown to exert cytoprotective effects in models of acute myocardial infarction and represents a highly attractive therapeutic target. HMOX1 is the stress‐inducible enzyme responsible for the catabolism of heme, the functional backbone by which oxygen is carried in proteins like hemoglobin and cytochromes in the electron transport chain. As a potent inducer of HMOX1 and an FDA‐approved heme‐surrogate for the treatment of porphyria, hemin represents a novel treatment strategy for AMI.Translation of HMOX1‐targeted therapeutics to the clinic has been stymied by a singular focus on HMOX1 and an incomplete understanding of fundamental heme metabolism regulation in response to hypoxia, ischemia or pharmacological stimulation with hemin. To date, studies investigating hemin pharmacology and its use in models of ischemic injury are limited. The objective of the present study was to provide a temporal and pharmacokinetic characterization of the changes in heme regulatory enzyme expression in response to hemin and ischemic cardiac injury (i.e. AMI).Echocardiographic, hemodynamic and protein quantification analyses were performed in male CD‐1 mice following a single intraperitoneal hemin injection, permanent ligation AMI, or daily hemin treatment pre‐ or post‐AMI with corresponding sham and vehicle controls. Temporal changes in left ventricular heme regulatory enzyme expression were measured in response to hemin and AMI. This is the first study to holistically characterize the effects of either AMI and/or hemin on endogenous heme regulation in the myocardium.Hemin markedly increased HMOX1 levels and instigated isoform switching between heme‐synthesizing enzymes in the left ventricle of healthy mice. This isoform switching was further observed with AMI and suggests a progressive increase in heme bioavailability with ischemic injury. Interestingly, HMOX1 — a heme and stress‐inducible enzyme — was induced at only 3 days post‐AMI and did not increase concomitantly with heme‐synthesizing enzymes.Echocardiographic analyses showed preserved left ventricular morphology and cardiac output with hemin administration both pre‐ and post‐AMI. Invasive hemodynamics revealed preserved left ventricular function in mice administered daily hemin when initiated 3h pre‐AMI but not when initiated 2h post‐AMI. Similarly, hemin administration significantly increased H9C2 cardiomyotubule viability when administered prior to H2O2‐mediated injury but not with simultaneous or 2h post‐injury hemin administration. This suggests that time‐dependent mechanisms are involved in conferring hemin‐mediated cardioprotection and could suggest differential mechanisms related to myocyte survival and cardiac remodelling.Support or Funding InformationNatural Sciences and Engineering Research Council of Canada, Nova Scotia Health Research Foundation

Characterization of Cystoisospora suis sexual stages in vitro

BackgroundThe porcine coccidium Cystoisospora suis is characterized by a complex life-cycle during which asexual multiplication is followed by sexual development with two morphologically distinct cell types, the micro- and macrogametes. Genes related to the sexual stages and cell cycle progression were previously identified in related Apicomplexa. Dynein light chain type 1 and male gamete fusion factor HAP2 are restricted to microgametes. Tyrosine-rich proteins and oocyst wall proteins are a part of the oocyst wall. The Rad51/Dmc1-like protein and Nima-related protein kinases are associated with the cell cycle and fertilization process. Here, the sexual stages of C. suis were characterized in vitro morphologically and for temporal expression changes of the mentioned genes to gain insight into this poorly known phase of coccidian development.MethodsSexual stages of C. suis developing in vitro in porcine intestinal epithelial cells were examined by light and electron microscopy. The transcriptional levels of genes related to merozoite multiplication and sexual development were evaluated by quantitative real-time PCR at different time points of cultivation. Transcription levels were compared for parasites in culture supernatants at 6–9 days of cultivation (doc) and intracellular parasites at 6–15 doc.ResultsSexual stage of C. suis was detected during 8–11 doc in vitro. Microgamonts (16.8 ± 0.9 µm) and macrogamonts (16.6 ± 1.1 µm) are very similar in shape and size. Microgametes had a round body (3.5 ± 0.5 µm) and two flagella (11.2 ± 0.5 µm). Macrogametes were spherical with a diameter of 12.1 ± 0.5 µm. Merozoite gene transcription peaked on 10 doc and then declined. Genes related to the sexual stages and cell cycle showed an upregulation with a peak on 13 doc, after which they declined.ConclusionsThe present study linked gene expression changes to the detailed morphological description of C. suis sexual development in vitro, including fertilization, meiosis and oocyst formation in this unique model for coccidian parasites. Following this process at the cellular and molecular level will elucidate details on potential bottlenecks of C. suis development (applicable for coccidian parasites in general) which could be exploited as a novel target for control.