Gene network expression of whole blood leukocytes in dairy cows with different milk yield at dry-off

Dairy cows at dry-off undergo several management and physiological changes, resulting in alterations in plasma biomarkers of inflammation, oxidative stress, and immune system. High milk yield at the end of lactation exacerbates these responses. The underlying mechanism of these changes has yet to be elucidated. We hypothesized altered leukocyte gene expression after dry-off and different responses in cows with different milk yield. Thirteen Holstein dairy cows were sampled at the turn of dry-off to investigated whole blood leukocyte gene expression and were grouped according to the average milk yield during the last week of lactation: low (< 15 kg/d) and high milk yield (> 15 kg/d). Blood samples were collected in PAXgene tubes (Preanalytix, Hombrechtikon, Switzerland) at -7, 7, and 34 days from dry-off (DFD) to measure mRNA abundance of 37 genes. Normalized gene abundance data were subjected to MIXED model ANOVA (SAS Institute Inc., Cary, NC). Compared with -7 DFD, at 7 DFD RNA abundance of lipoxygenase genes (ALOX5, ALOX15) and myeloperoxidase (MPO) increased, and that of the antioxidant gene (SOD2) decreased. Meanwhile, genes related to recognition and immune mediation (CD16, MYD88, TLR2), migration and cell adhesion (CX3CR1, ITGAL, ITGB2, TLN1), and the antimicrobial gene MMP9 were downregulated at 7 or 34 DFD, whereas the antimicrobial IDO1 gene was upregulated. Compared with low-producing cows, cows with high milk yield at dry-off cows had upregulated expression of the pro-inflammatory cytokines IL8 and IL18 and a greater reduction in transcript abundance of the toll-like receptor (TLR) recognition-related gene TLR2. Overall, the dry-off confirmed to be a phase of intense changes, triggering an inflammatory response and somewhat suppressing leukocyte immune function. In cows with high milk yield during the week before dry-off, the inflammatory response was exacerbated.

Postischemic Neuroprotection Associated With Anti-Inflammatory Effects by Mesenchymal Stromal Cell-Derived Small Extracellular Vesicles in Aged Mice

Background and Purpose: Small extracellular vesicles (sEVs) obtained from mesenchymal stromal cells (MSCs) were shown to induce ischemic neuroprotection in mice by modulating the brain infiltration of leukocytes and, specifically polymorphonuclear neutrophils. So far, effects of MSC-sEVs were only studied in young ischemic rodents. We herein examined the effects of MSC-sEVs in aged mice. Methods: Male and female C57Bl6/j mice (8–10 weeks or 15–24 months) were exposed to transient intraluminal middle cerebral artery occlusion. Vehicle or sEVs (equivalent of 2×10 6 MSCs) were intravenously administered. Neurological deficits, ischemic injury, blood-brain barrier integrity, brain leukocyte infiltration, and blood leukocyte responses were evaluated over up to 7 days. Results: MSC-sEV delivery reduced neurological deficits, infarct volume, brain edema, and neuronal injury in young and aged mice of both sexes, when delivered immediately postreperfusion or with 6 hours delay. MSC-sEVs decreased leukocyte and specifically polymorphonuclear neutrophil, monocyte, and macrophage infiltrates in ischemic brains of aged mice. In peripheral blood, the number of monocytes and activated T cells was significantly reduced by MSC-sEVs. Conclusions: MSC-sEVs induce postischemic neuroprotection and anti-inflammation in aged mice.

The Effect of Insect Repellent Exposure on Leukocyte Profile and Histopathologic Findings in Lungs

Organophosphate compounds in insect repellent have a role in contributing to mosquito mortality but have toxic effects for humans when exposed for a long time. The research is aimed to analyze the effect of insect repellent exposure in blood leukocyte profile and histopathologic findings in lungs. The study used thirty males Rattus novergicus, which were divided into three groups, such as electric liquid insect repellent (P1) with contain 0.031% dimefluthrin, anti-mosquito coils (P2) with 0.014% dimefluthrin, and electric mat mosquito repellent with 0.566% dimefluthrin for 8 hours in 20 days respectively. Leukocyte profiles were determined by using the blood smear method, and the lung’s health was identified by histopathologic findings. Based on the results study showed mosquito coils exposure increase the lymphocytes count. Meanwhile, the electric liquid-repellent increased the basophil’s numbers. The electric mat exposure had more eosinophils, neutrophils stab, neutrophils segment, and monocytes in the blood. The leukocyte profile of each group showed there were no statistically significant differences (P-value > 0.05). Based on histopathology, lung findings showed that the electric mat exposure contributed to cells degeneration 7.5% and pleural thickening 30%. The higher dimefluthrin concentrations in insect repellents could affect leukocyte profile and lungs health.

FOXO3, Telomere Dynamics, and Healthy Brain Aging: A COBRE Study

Human longevity is linked to genetic, cellular, and other complex biological and psychosocial traits. Aging is typically accompanied by gradual brain atrophy and cognitive decline, but the mechanisms are unclear. Cellular aging, characterized by telomere shortening and altered telomerase activity, is related to mortality and brain aging. Decelerated brain aging is associated with greater peripheral blood leukocyte telomere length (LTL) and, we hypothesize, may be linked to FOXO3 genotype. We will use MRI to assess brain structure and function cross-sectionally in 100 Kuakini Honolulu Heart Program Offspring. Atrophy and disrupted functional connectivity, markers of brain aging, will be examined in relation to FOXO3 and LTL. Associations between brain structural and functional differences, FOXO3 genotype and LTL will be investigated over a wide range of ages, controlling for other biological and psychosocial factors. Results may provide insight into mechanisms influencing the rate of brain aging, and may eventually extend human healthspan.

Polystyrene microplastic particles induce endothelial activation

Due to its increasing production, durability and multiple applications, plastic is a material we encounter every day. Small plastic particles from the μm to the mm range are classified as microplastics and produced for cosmetic and medical products, but are also a result of natural erosion and decomposition of macroplastics. Although being omnipresent in our environment and already detected in various organisms, less is known about the effects of microplastics on humans in general, or on vascular biology in particular. Here we investigated the effects of carboxylated polystyrene microplastic particles (PS, 1 μm) on murine endothelial and immune cells, which are both crucially involved in vascular inflammation, using in vitro and in vivo approaches. In vitro, PS induced adhesion molecule expression in endothelial cells with subsequent adhesion of leukocytes both under static and flow conditions. In monocytic cells, PS enhanced pro-inflammatory cytokine expression and release. Accordingly, administering mice with PS led to enhanced aortic expression of cytokines and adhesion molecules. Furthermore, we identified neutrophils as the PS-clearing blood leukocyte population. The findings from this study for the first time indicate polystyrene microplastic as a new environmental risk factor for endothelial inflammation.

A Proteomic Analysis of the Effects of Yessotoxin and Di-Desulfoyessotoxin on Yeast and Mammalian Cells

<p>Yessotoxin (YTX) is a disulfated polycyclic polyether, produced by dinoflagellate algae. It is known to accumulate in edible shellfish, raising concerns about its potential risk to human health. YTX was initially classified as a diarrhetic shellfish poisoning toxin, due to commonly being extracted alongside toxins of this variety. However, YTX does not induce any of the effects characteristic of this group. A separate category for YTXs was established by the European Commission in 2002 and a limit of 1 mg/kg of shellfish meat was established. YTX has been shown to be an apoptosis inducer in a variety of cell lines in vitro. It has also been shown to be lethal to mice when administered by intra-peritoneal injection. However, when administered orally only limited toxicity is observed. The di-desulfated derivative (dsYTX) has also been shown to be lethal to mice following intra-peritoneal injection. However it causes damage mainly to the liver, whereas YTX appears to target the heart. The mechanism of action of YTX is still unknown. The goals of this project were to use proteomic techniques, to examine the effects of YTX and dsYTX on Saccharomyces cerevisiae and human promyelocytic leukemic blood leukocyte (HL60) cells. Young et al. (2009) showed that the major proteins affected by YTX in HepG2 cells were heterogeneous ribonucleoproteins (hnRNPs), lamins, cathepsins and heat shock proteins. HnRNPs had not previously been identified as possible targets of YTX. Alterations of hnRNP levels were also seen in HL60 cells treated with microtubule stabilising agents, peloruside A or paclitaxel (Wilmes et al., 2011, 2012). No differences in cell morphology or significant changes in protein abundance were observed when S. cerevisiae cells were exposed to YTX. A small number of significant changes in abundance were detected when these cells were exposed to dsYTX. The small number of protein changes seen is possibly due to poor toxin entrance into the cell through the yeast cell wall, lack of protein targets structurally homologous to those found in mammalian cells, or fast removal of the toxin through export pumps. Twenty-four hour incubation of HL60 cells with YTX resulted in increased cell death but no change in cell morphology. Treatment with dsYTX caused cells to aggregate into clusters and a 24% decrease in the number of live cells. Increases were found in the abundance of β-actin, hnRNP A and BiP proteins in response to dsYTX treatment. Decreases in these proteins were seen in HepG2 cells treated with YTX for 24 hours. As seen in S. cerevisiae cells, dsYTX had a greater effect in HL60 cells compared with YTX. Overall, the results provide some support for the previously identified effect on hnRNPs in mammalian cells exposed to YTX.</p>

A Proteomic Analysis of the Effects of Yessotoxin and Di-Desulfoyessotoxin on Yeast and Mammalian Cells

<p>Yessotoxin (YTX) is a disulfated polycyclic polyether, produced by dinoflagellate algae. It is known to accumulate in edible shellfish, raising concerns about its potential risk to human health. YTX was initially classified as a diarrhetic shellfish poisoning toxin, due to commonly being extracted alongside toxins of this variety. However, YTX does not induce any of the effects characteristic of this group. A separate category for YTXs was established by the European Commission in 2002 and a limit of 1 mg/kg of shellfish meat was established. YTX has been shown to be an apoptosis inducer in a variety of cell lines in vitro. It has also been shown to be lethal to mice when administered by intra-peritoneal injection. However, when administered orally only limited toxicity is observed. The di-desulfated derivative (dsYTX) has also been shown to be lethal to mice following intra-peritoneal injection. However it causes damage mainly to the liver, whereas YTX appears to target the heart. The mechanism of action of YTX is still unknown. The goals of this project were to use proteomic techniques, to examine the effects of YTX and dsYTX on Saccharomyces cerevisiae and human promyelocytic leukemic blood leukocyte (HL60) cells. Young et al. (2009) showed that the major proteins affected by YTX in HepG2 cells were heterogeneous ribonucleoproteins (hnRNPs), lamins, cathepsins and heat shock proteins. HnRNPs had not previously been identified as possible targets of YTX. Alterations of hnRNP levels were also seen in HL60 cells treated with microtubule stabilising agents, peloruside A or paclitaxel (Wilmes et al., 2011, 2012). No differences in cell morphology or significant changes in protein abundance were observed when S. cerevisiae cells were exposed to YTX. A small number of significant changes in abundance were detected when these cells were exposed to dsYTX. The small number of protein changes seen is possibly due to poor toxin entrance into the cell through the yeast cell wall, lack of protein targets structurally homologous to those found in mammalian cells, or fast removal of the toxin through export pumps. Twenty-four hour incubation of HL60 cells with YTX resulted in increased cell death but no change in cell morphology. Treatment with dsYTX caused cells to aggregate into clusters and a 24% decrease in the number of live cells. Increases were found in the abundance of β-actin, hnRNP A and BiP proteins in response to dsYTX treatment. Decreases in these proteins were seen in HepG2 cells treated with YTX for 24 hours. As seen in S. cerevisiae cells, dsYTX had a greater effect in HL60 cells compared with YTX. Overall, the results provide some support for the previously identified effect on hnRNPs in mammalian cells exposed to YTX.</p>

364. Individualized Prognostics in COVID-19 Facilitated by Computer Recognition of Blood Leukocyte Subsets

Background To determine whether CBC differentials of COVID+ inpatients can predict, at admission, both maximum oxygen requirements (MOR) and 30-day mortality. Methods Based on an approved IRB protocol, CBC differentials from the first 3 days of hospitalization of 12 SARS CoV-2 infected patients were retrospectively extracted from hospital records and analyzed with a privately owned Pattern Recognition Software (PRS, US Patent 10,429,389 B2) previously validated in sepsis, HIV, and hantavirus infections. PRS partitions the data into subsets immunologically dissimilar from one another, although internally similar. Results Regardless of the angle considered, the classic analysis −which measured the percentages of lymphocytes, monocytes, and neutrophils− did not distinguish outcomes (A). In contrast, non-overlapping patterns generated by the PRS differentiated 3 (left, vertical, and right) groups of patients (B). One subset was only composed of survivors (B). The remaining subsets included the highest oxygenation requirements (B). At least two immunologically interpretable, multi-cellular indicators distinguished the 3 data subsets with statistically significant differences (C, p≤ 0.05). Survivors (the left subset) showed lower N/L and/or higher M/L ratios than non-survivors (the vertical subset, C).Therefore, PRS partitioned the data into subsets that displayed both biological and significant differences. Because it offers visually explicit information, clinicians do not require a specialized training to interpret PRS-generated results. CBCs vs. outcomes - Software-analyzed CBCs vs. outcomes Conclusion (1) Analysis of blood leukocyte data predicts MOR and 30-d mortality. (2) Real time PRS analysis facilitates personalized medical decisions. (3) PRS measures two dimensions rarely assessed: multi-cellularity and dynamics. (4) Even with very small datasets, PRS may achieve statistical significance. (5) Larger COVID+ infected cohort is being analyzed for potential commercialization. Disclosures Claudia R. Libertin, MD, Gilead (Grant/Research Support)