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At least 1,045 records · Page 58
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Vascular endothelial growth factor receptor-1 (FLT1) interactions with amyloid-beta in Alzheimer’s disease: A putative biomarker of amyloid-induced vascular damage

We have identified FLT1 as a protein that changes during Alzheimer's disease (AD) whereby higher brain protein levels are associated with more amyloid, more tau, and faster longitudinal cognitive decline. Given FLT1's role in angiogenesis and immune activation, we hypothesized that FLT1 is upregulated in response to amyloid pathology, driving a vascular-immune cascade resulting in neurodegeneration and cognitive decline. We sought to determine (1) if in vivo FLT1 levels (CSF and plasma) associate with biomarkers of AD neuropathology or differ between diagnostic staging in an aged cohort enriched for early disease, and (2) whether FLT1 expression interacts with amyloid on downstream outcomes, such as phosphorylated tau levels and cognitive performance. Additionally, we sought to replicate FLT1 interactions in the brain. The results showed that higher levels of FLT1 in CSF and post-mortem brain tissue related to increased tau, particularly among amyloid positive individuals. These analyses help clarify the potential utility of FLT1 as a biomarker among individuals with evidence of brain amyloidosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

When your cap matters: structural insights into self vs non-self recognition of 5' RNA by immunomodulatory host proteins

Cytosolic recognition of viral RNA is important for host innate immune responses. Differential recognition of self vs non-self RNA is a considerable challenge as the inability to differentiate may trigger aberrant immune responses. Recent work identified the composition of the RNA 5', including the 5' cap and its methylation state, as an important determinant of recognition by the host. Furthermore, recent studies have advanced our understanding of the modified 5' RNA recognition and viral antagonism of RNA receptors. Here, we will discuss RIG-I and IFIT proteins as examples of host proteins that detect dsRNA and ssRNA, respectively.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

The concept of bio-corona in modulating the toxicity of engineered nanomaterials (ENM)

Besides the wide use of engineered nanomaterials (ENM) in technical products, their application spectrum in biotechnology and biomedicine is steadily increasing. In complex physiological environments the physico-chemical properties and the behavior of nanoparticles (NPs) are challenging to characterize. Biomolecules rapidly adsorb to the nanomaterial, leading to the formation of the protein/biomolecule corona, which critically affects the nanomaterials' (patho)biological and technical identities. This formation can trigger an immune response and affect nanoparticles' toxicity and targeting capabilities. In this review, we provide a survey of recent findings on the (protein)corona-nanoparticle interaction and discuss how the corona modulates both cytotoxicity and the immune response as well as to improve the efficacy of targeted delivery of nanocarriers. - Highlights: • “Nanotoxicology” has emerged an autonomous field with an explosive growth. • Nanomaterials adsorb (bio)molecules forming the so-called (bio)molecule corona. • (Fine-)tune of the corona composition could enable new possibilities in nanomedicine.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Effects of acute ethanol exposure on cytokine production by primary airway smooth muscle cells

Both chronic and binge alcohol abuse can be significant risk factors for inflammatory lung diseases such as acute respiratory distress syndrome and chronic obstructive pulmonary disease. However, metabolic basis of alcohol-related lung disease is not well defined, and may include key metabolites of ethanol [EtOH] in addition to EtOH itself. Therefore, we investigated the effects of EtOH, acetaldehyde [ACE], and fatty acid ethyl esters [FAEEs] on oxidative stress, endoplasmic reticulum (ER) stress, AMP-activated protein kinase (AMPK) signaling and nuclear translocation of phosphorylated (p)-NF-κB p65 in primary human airway smooth muscle (HASM) cells stimulated to produce cytokines using LPS exposure. Both FAEEs and ACE induced evidence of cellular oxidative stress and ER stress, and increased p-NF-κB in nuclear extracts. EtOH and its metabolites decreased p-AMPKα activation, and induced expression of fatty acid synthase, and decreased expression of sirtuin 1. In general, EtOH decreased secretion of IP-10, IL-6, eotaxin, GCSF, and MCP-1. However, FAEEs and ACE increased these cytokines, suggesting that both FAEEs and ACE as compared to EtOH itself are proinflammatory. A direct effect of EtOH could be consistent with blunted immune response. Collectively, these two features of EtOH exposure, coupled with the known inhibition of innate immune response in our model might explain some clinical manifestations of EtOH exposure in the lung. - Highlights: • Metabolic basis for EtOH toxicity was studied in human airway smooth muscle (HASM) cells. • In HASM cells, EtOH metabolites were found to be relatively more toxic than EtOH itself. • EtOH metabolites mediate deactivation of AMPK via oxidative stress and ER stress. • EtOH metabolites were found to be more proinflammatory than EtOH itself in HASM cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Differences in allergic inflammatory responses between urban PM2.5 and fine particle derived from desert-dust in murine lungs

The biological and chemical natures of materials adsorbed onto fine particulate matter (PM2.5) vary by origin and passage routes. The exacerbating effects of the two samples—urban PM2.5 (U-PM2.5) collected during the hazy weather in a Chinese city and fine particles (ASD-PM2.5) collected during Asian sand dust (ASD) storm event days in Japan—on murine lung eosinophilia were compared to clarify the role of toxic materials in PM2.5. The amounts of β-glucan and mineral components were higher in ASD-PM2.5 than in U-PM2.5. On the other hand, organic chemicals, including polycyclic aromatic hydrocarbons (PAHs), were higher in U-PM2.5 than in ASD-PM2.5. When BALB/c mice were intratracheally instilled with U-PM2.5 and ASD-PM2.5 (total 0.4 mg/mouse) with or without ovalbumin (OVA), various biological effects were observed, including enhancement of eosinophil recruitment induced by OVA in the submucosa of the airway, goblet cell proliferation in the bronchial epithelium, synergic increase of OVA-induced eosinophil-relevant cytokines and a chemokine in bronchoalveolar lavage fluid, and increase of serum OVA-specific IgG1 and IgE. Data demonstrate that U-PM2.5 and ASD-PM2.5 induced allergic inflammatory changes and caused lung pathology. U-PM2.5 and ASD-PM2.5 increased F4/80{sup +} CD11b{sup +} cells, indicating that an influx of inflammatory and exudative macrophages in lung tissue had occurred. The ratio of CD206 positive F4/80{sup +} CD11b{sup +} cells (M2 macrophages) in lung tissue was higher in the OVA + ASD-PM2.5 treated mice than in the OVA + U-PM2.5 treated mice. These results suggest that the lung eosinophilia exacerbated by both PM2.5 is due to activation of a Th2-associated immune response along with induced M2 macrophages and the exacerbating effect is greater in microbial element (β-glucan)-rich ASD-PM2.5 than in organic chemical-rich U-PM2.5. - Highlights: • The aggravating effects of urban-PM2.5 and desert-PM2.5 on lung eosinophilia were compared. • Both PM2.5 enhanced Th2-immune response along with induced M2 macrophages. • The effect is greater in desert-PM2.5 than in organic chemical-rich urban-PM2.5. • Desert-PM2.5 may cause greater effects upon human respiratory health than urban-PM2.5.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Smoking-related microRNAs and mRNAs in human peripheral blood mononuclear cells

Teenager smoking is of great importance in public health. Functional roles of microRNAs have been documented in smoke-induced gene expression changes, but comprehensive mechanisms of microRNA-mRNA regulation and benefits remained poorly understood. We conducted the Teenager Smoking Reduction Trial (TSRT) to investigate the causal association between active smoking reduction and whole-genome microRNA and mRNA expression changes in human peripheral blood mononuclear cells (PBMC). A total of 12 teenagers with a substantial reduction in smoke quantity and a decrease in urine cotinine/creatinine ratio were enrolled in genomic analyses. In Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA), differentially expressed genes altered by smoke reduction were mainly associated with glucocorticoid receptor signaling pathway. The integrative analysis of microRNA and mRNA found eleven differentially expressed microRNAs negatively correlated with predicted target genes. CD83 molecule regulated by miR-4498 in human PBMC, was critical for the canonical pathway of communication between innate and adaptive immune cells. Our data demonstrated that microRNAs could regulate immune responses in human PBMC after habitual smokers quit smoking and support the potential translational value of microRNAs in regulating disease-relevant gene expression caused by tobacco smoke. - Highlights: • We conducted a smoke reduction trial program and investigated the causal relationship between smoke and gene regulation. • MicroRNA and mRNA expression changes were examined in human PBMC. • MicroRNAs are important in regulating disease-causal genes after tobacco smoke reduction.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

MicroRNA-mediated Th2 bias in methimazole-induced acute liver injury in mice

MicroRNA (miRNA) is a class of small non-coding RNAs containing approximately 20 nucleotides that negatively regulate target gene expression. Little is known about the role of individual miRNAs and their targets in immune- and inflammation-related responses in drug-induced liver injury. In the present study, involvement of miRNAs in the T helper (Th) 2-type immune response was investigated using a methimazole (MTZ)-induced liver injury mouse model. Co-administration of L-buthionine-S,R-sulfoximine and MTZ induced acute hepatocellular necrosis and elevated plasma levels of alanine aminotransferase (ALT) from 4 h onward in female Balb/c mice. The hepatic mRNA expression of Th2 promotive factors was significantly increased concomitantly with plasma ALT levels. In contrast, the hepatic mRNA expression of Th2 suppressive factors was significantly decreased during the early phase of liver injury. Comprehensive profiling of hepatic miRNA expression was analyzed before the onset of MTZ-induced liver injury. Using in silico prediction of miRNAs that possibly regulate Th2-related genes and subsequent quantification, we identified up-regulation of expression of miR-29b-1-5p and miR-449a-5p. Among targets of these miRNAs, down-regulation of Th2 suppressive transcription factors, such as SRY-related HMG-box 4 (SOX4) and lymphoid enhancer factor-1 (LEF1), were observed from the early phase of liver injury. In conclusion, negative regulation of the expression of SOX4 by miR-29b-1-5p and that of LEF1 by miR-449a-5p is suggested to play an important role in the development of Th2 bias in MTZ-induced liver injury. - Highlights: • Methimazole induced hepatic Th2 bias in the pathogenesis of liver injury in mice. • Rapid down-regulation of SOX4 and LEF1 may initiate and/or maintain hepatic Th2 bias. • Negative regulation of SOX4 by miR-29b-1-5p and LEF1 by miR-449a-5p was suggested.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Lack of TAK1 in dendritic cells inhibits the contact hypersensitivity response induced by trichloroethylene in local lymph node assay

Trichloroethylene (TCE) is a ubiquitous environmental contaminant. Occupational TCE exposure has been associated with severe, generalized contact hypersensitivity (CHS) skin disorder. The development of CHS depends on innate and adaptive immune functions. Transforming growth factor-β activated kinase-1 (TAK1) controls the survival of dendritic cells (DCs) that affect the immune system homeostasis. We aimed to investigate the role of TAK1 activity in DC on TCE-induced CHS response. Control mice and DC-specific TAK1 deletion mice were treated with 80% (v/v) TCE using local lymph node assay (LLNA) to establish a TCE-induced CHS model. The draining lymph nodes (DLNs) were excised and the lymphocytes were measure for proliferation by BrdU-ELISA, T-cell phenotype analysis by flow cytometry and signaling pathway activation by western blot. The ears were harvested for histopathological analysis. Control mice in the 80% TCE group displayed an inflammatory response in the ears, increased lymphocyte proliferation, elevated regulatory T-cell and activated T-cell percentages, and more IFN-γ producing CD8{sup +} T cells in DLNs. In contrast to control mice, DC-specific TAK1 deletion mice in the 80% TCE group showed an abolished CHS response and this was associated with defective T-cell expansion, activation and IFN-γ production. This effect may occur through Jnk and NF-κB signaling pathways. Overall, this study demonstrates a pivotal role of TAK1 in DCs in controlling TCE-induced CHS response and suggests that targeting TAK1 function in DCs may be a viable approach to preventing and treating TCE-related occupational health hazards. - Highlights: • Lack of TAK1 in DC caused an abolished TCE-induced CHS response. • TAK1 in DCs was essential to maintain the homeostasis of T cells in TCE-induced CHS. • Intact TAK1 in DCs was critical to promote T-cell priming in TCE-induced CHS. • DC-specific TAK1 deficiency abolished the TCE-mediated phosphorylation of Jnk.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Comparative health effects in mice of Libby amphibole asbestos and a fibrous amphibole from Arizona

This project developed from studies demonstrating that Libby Amphibole Asbestos (LAA) causes a non-typical set of health outcomes not generally reported for asbestos, including systemic autoimmunity and an unusual and devastating lamellar pleural thickening that progresses to severe pulmonary dysfunction and death. Further, mineral fiber mixtures with some similarities to LAA have recently been discovered in southern Nevada and northwestern Arizona, where the material exists in extensive recreational areas and is present in yards, roads, parking lots and school yards. The objective was to compare the health outcomes in mice exposed to either LAA or the fibrous amphiboles collected in Arizona at the Lake Mead National Recreational Area at very low doses to represent environmental exposures. In this study, the fibrous amphibole asbestos sample from Arizona (AzA) is composed of winchite (69%), actinolite (22%), and non-amphibole minerals (9%) and has a mean aspect ratio of 16.7 ± 0.9. Fibrous amphibole asbestos from Libby (LAA) is composed of winchite (70%), richterite (9%), tremolite (5%), and non-amphibole minerals (16%) with a mean aspect ratio of 8.4 ± 0.7. C57BL/6 mice were exposed by oropharyngeal aspiration to fiber suspensions at a very low dose of 3 μg/mouse. After seven months, both LAA- and AzA-exposed mice had indices of chronic immune dysfunction related to a T{sub H}17 cytokine profile, with B cell activation, autoantibody production and proteinuria, suggesting kidney involvement. In addition, both exposures led to significant lung and pleural fibrosis. These data suggest that there is risk of pulmonary disease and autoimmune outcomes with environmental exposure to amphibole asbestos, and that this is not limited to Libby, Montana. - Highlights: • Health effects of Arizona versus Libby amphibole asbestos were comparable in mice. • Both fibers led to immune changes consistent with autoimmune dysfunction. • Both fibers caused significant increases in interstitial and pleural fibrosis. • Novel sources of asbestos could pose health risks even at low exposure levels.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Enhancement of antigen-specific CD4 + and CD8 + T cell responses using a self-assembled biologic nanolipoprotein particle vaccine

To address the need for vaccine platforms that induce robust cell-mediated immunity, we investigated the potential of utilizing self-assembling biologic nanolipoprotein particles (NLPs) as an antigen and adjuvant delivery system to induce antigen-specific murine T cell responses. Here, we utilized OT-I and OT-II TCR-transgenic mice to investigate the effects of NLP-mediated delivery of the model antigen ovalbumin (OVA) on T cell activation. Delivery of OVA with the TLR4 agonist monophosphoryl lipid A (MPLA) in the context of NLPs significantly enhanced the activation of both CD4 + and CD8 + T cells in vitro compared to co-administration of free OVA and MPLA. Upon intranasal immunization of mice harboring TCR-transgenic cells, NLPs enhanced the adjuvant effects of MPLA and the in vivo delivery of OVA, leading to significantly increased expansion of CD4 + and CD8 + T cells in lung-draining lymph nodes. Therefore, NLPs are a promising vaccine platform for inducing T cell responses following intranasal administration.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Cross-reactive immunogenicity of group A streptococcal vaccines designed using a recurrent neural network to identify conserved M protein linear epitopes

The M protein of group A streptococci (Strep A) is a major virulence determinant and protective antigen. The N-terminal sequence of the protein defines the more than 200 M types of Strep A and also contains epitopes that elicit opsonic antibodies, some of which cross-react with heterologous M types. Current efforts to develop broadly protective M protein-based vaccines are directed at identifying potential cross-protective epitopes located in the N-terminal regions of cluster-related M proteins for use as vaccine antigens. In this study, we have used a comprehensive approach using the recurrent neural network ABCpred and IEDB epitope conservancy analysis tools to predict 16 residue linear B-cell epitopes from 117 clinically relevant M types of Strep A (~88% of global Strep A infections). Furthermore, to examine the immunogenicity of these epitope-based vaccines, nine peptides that together shared ≥60% sequence identity with 37 heterologous M proteins were incorporated into two recombinant hybrid protein vaccines, in which the epitopes were repeated 2 or 3 times, respectively. The combined immune responses of immunized rabbits showed that the vaccines elicited significant levels of antibodies against all nine vaccine epitopes present in homologous N-terminal 1–50 amino acid synthetic M peptides, as well as cross-reactive antibodies against 16 of 37 heterologous M peptides predicted to contain similar epitopes. The epitope-specificity of the cross-reactive antibodies was confirmed by ELISA inhibition assays and functional opsonic activity was assayed in HL-60-based bactericidal assays. The results provide important information for the future design of broadly protective M protein-based Strep A vaccines.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

A heterologous prime-boosting strategy with replicating Vaccinia virus vectors and plant-produced HIV-1 Gag/dgp41 virus-like particles

Showing modest efficacy, the RV144 HIV-1 vaccine clinical trial utilized a non-replicating canarypox viral vector and a soluble gp120 protein boost. Here we built upon the RV144 strategy by developing a novel combination of a replicating, but highly-attenuated Vaccinia virus vector, NYVAC-KC, and plant-produced HIV-1 virus-like particles (VLPs). Both components contained the full-length Gag and a membrane anchored truncated gp41 presenting the membrane proximal external region with its conserved broadly neutralizing epitopes in the pre-fusion conformation. We tested different prime/boost combinations of these components in mice and showed that the group primed with NYVAC-KC and boosted with both the viral vectors and plant-produced VLPs have the most robust Gag-specific CD8 T cell responses, at 12.7% of CD8 T cells expressing IFN-γ in response to stimulation with five Gag epitopes. The same immunization group elicited the best systemic and mucosal antibody responses to Gag and dgp41 with a bias towards IgG1. - Highlights: • We devised a prime/boost anti HIV-1 vaccination strategy modeled after RV144. • We used plant-derived virus-like particles (VLPs) consisting of Gag and dgp41. • We used attenuated, replicating vaccinia virus vectors expressing the same antigens. • The immunogens elicited strong cellular and humoral immune responses.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Kobuvirus VP3 protein restricts the IFN-β-triggered signaling pathway by inhibiting STAT2-IRF9 and STAT2-STAT2 complex formation

Emerged porcine kobuvirus (PKV) has adversely affected the global swine industry since 2008, but the etiological biology of PKV is unclear. Screening PKV-encoded structural and non-structural proteins with a type I IFN-responsive luciferase reporter showed that PKV VP3 protein inhibited the IFN-β-triggered signaling pathway, resulting in the decrease of VSV-GFP replication. QPCR data showed that IFN-β downstream cytokine genes were suppressed without cell-type specificity as well. The results from biochemical experiments indicated that PKV VP3 associated with STAT2 and IRF9, and interfered with the formation of the STAT2-IRF9 and STAT2-STAT2 complex, impairing nuclear translocation of STAT2 and IRF9. Taken together, these data reveal a new mechanism for immune evasion of PKV. - Highlights: •PKV VP3 inhibits the IFN-β-triggered signaling pathway. •VP3 associates with STAT2 and IRF9. •VP3 blocks the STAT2-IRF9 nuclear translocation. •VP3 utilizes a novel strategy for innate immune evasion.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

Evaluation of two inoculation routes of an adenovirus-mediated viral protein inhibitor in a Crimean-Congo hemorrhagic fever mouse model

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne nairovirus with a wide geographic spread that can cause severe and lethal disease. No specific medical countermeasures are approved to combat this illness. The CCHFV L protein contains an ovarian tumor (OTU) domain with a cysteine protease thought to modulate cellular immune responses by removing ubiquitin and ISG15 post-translational modifications from host and viral proteins. Viral deubiquitinases like CCHFV OTU are attractive drug targets, as blocking their activity may enhance cellular immune responses to infection, and potentially inhibit viral replication itself. We previously demonstrated that the engineered ubiquitin variant CC4 is a potent inhibitor of CCHFV replication in vitro. A major challenge of the therapeutic use of small protein inhibitors such as CC4 is their requirement for intracellular delivery, e.g., by viral vectors. In this study, we examined the feasibility of in vivo CC4 delivery by a replication-deficient recombinant adenovirus (Ad-CC4) in a lethal CCHFV mouse model. Since the liver is a primary target of CCHFV infection, we aimed to optimize delivery to this organ by comparing intravenous (tail vein) and intraperitoneal injection of Ad-CC4. While tail vein injection is a traditional route for adenovirus delivery, in our hands intraperitoneal injection resulted in higher and more widespread levels of adenovirus genome in tissues, including, as intended, the liver. However, despite promising in vitro results, neither route of in vivo CC4 treatment resulted in protection from a lethal CCHFV infection.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Mitochondrial reactive oxygen species mediate the lipopolysaccharide-induced pro-inflammatory response in human gingival fibroblasts

Although periodontal diseases are initiated by bacteria that colonize the tooth surface and gingival sulcus, the host response is believed to play an essential role in the breakdown of connective tissue and bone. Mitochondrial reactive oxygen species (mtROS) have been proposed to regulate the activation of the inflammatory response by the innate immune system. However, the role of mtROS in modulating the response of human gingival fibroblasts (HGFs) to immune stimulation by lipopolysaccharides (LPS) has yet to be fully elucidated. Here, we showed that LPS from Porphyromonas gingivalis stimulated HGFs to increase mtROS production, which could be inhibited by treatment with a mitochondrial-targeted exogenous antioxidant (mito-TEMPO) or transfection with manganese superoxide dismutase (MnSOD). A time-course study revealed that an increase in the concentration of mtROS preceded the expression of inflammatory cytokines in HGFs. Mito-TEMPO treatment or MnSOD transfection also significantly prevented the LPS-induced increase of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α. Furthermore, suppressing LPS-induced mtROS generation inhibited the activation of p38, c-Jun N-terminal kinase, and inhibitor of nuclear factor-κB kinase, as well as the nuclear localization of nuclear factor-κB. These results demonstrate that mtROS generation is a key signaling event in the LPS-induced pro-inflammatory response of HGFs. - Highlights: • Inflammation is thought to promote pathogenic changes in periodontitis. • We investigated mtROS as a regulator of inflammation in gingival fibroblasts. • Targeted antioxidants were used to inhibit mtROS production after LPS challenge. • Inhibiting mtROS generation suppressed the secretion of pro-inflammatory cytokines. • JNK, p38, IKK, and NF-κB were shown to act as transducers of mtROS signaling.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Inflammatory responses of stromal fibroblasts to inflammatory epithelial cells are involved in the pathogenesis of bovine mastitis

Hypernomic secretion of epithelial cytokines has several effects on stromal cells. The contributions of inflammatory epithelial cells to stromal fibroblasts in bovine mammary glands with mastitis remain poorly understood. Here, we established an inflammatory epithelial cell model of bovine mastitis with gram-negative lipopolysaccharide (LPS) and gram-positive lipoteichoic acid (LTA) bacterial cell wall components. We characterized immune responses of mammary stromal fibroblasts induced by inflammatory epithelial cells. Our results showed that inflammatory epithelial cells affected stromal fibroblast characteristics by increasing inflammatory mediator expression, elevating extracellular matrix protein deposition, decreasing proliferation capacity, and enhancing migration ability. The changes in stromal fibroblast proliferation and migration abilities were mediated by signal molecules, such as WNT signal pathway components. LPS- and LTA-induced inflammatory epithelial cells triggered different immune responses in stromal fibroblasts. Thus, in mastitis, bovine mammary gland stromal fibroblasts were affected by inflammatory epithelial cells and displayed inflammation-specific changes, suggesting that fibroblasts play crucial roles in bovine mastitis. - Highlights: • Inflammatory BMEs affect the properties of BMFs during mastitis. • BMEs inhibited the proliferation and promoted the migration of BMFs. • BMEs enhanced secretion of inflammatory mediators and deposition of ECM in BMFs. • Changes of the properties of BMFs were mediated by specific signal molecules.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Hypoxia regulates microRNA expression in the human carotid body

The carotid body (CB) is the key sensing organ for physiological oxygen levels in the body. Under conditions of low oxygen (hypoxia), the CB plays crucial roles in signaling to the cardiorespiratory center in the medulla oblongata for the restoration of oxygen homeostasis. How hypoxia regulates gene expression in the human CB remains poorly understood. While limited information on transcriptional regulation in animal CBs is available, the identity and impact of important post-transcriptional regulators such as non-coding RNAs, and in particular miRNAs are not known. Here we show using ex vivo experiments that indeed a number of miRNAs are differentially regulated in surgically removed human CB slices when acute hypoxic conditions were applied. Analysis of the hypoxia-regulated miRNAs shows that they target biological pathways with upregulation of functions related to cell proliferation and immune response and downregulation of cell differentiation and cell death functions. Comparative analysis of the human CB miRNAome with the global miRNA expression patterns of a large number of different human tissues showed that the CB miRNAome had a unique profile which reflects its highly specialized functional status. Nevertheless, the human CB miRNAome is most closely related to the miRNA expression pattern of brain tissues indicating that they may have the most similar developmental origins. - Highlights: • Hypoxia triggers differential expression of many miRNAs in the human carotid body. • This can lead to the upregulation of proliferation and immune response functions. • CB expression profile in the carotid body resembles the miRNA expression pattern in the brain. • miRNAs are involved in the regulation of carotid body functions including oxygen sensing.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Exosomes from Osteosarcoma and normal osteoblast differ in proteomic cargo and immunomodulatory effects on T cells

Background: Canine osteosarcoma (OSA) is the most common cancer of the appendicular skeleton and is associated with high metastatic rate to the lungs and poor prognosis. Recent studies have shown the impact of malignant-derived exosomes on immune cells and the facilitation of immune evasion. In the current study, we have characterized the proteomic profile of exosomes derived from healthy osteoblasts and osteosarcoma cell lines. We investigated the direct impact of these exosomes on healthy T cells. Results: Proteomic cargo of the malignant exosomes was markedly different from osteoblastic exosomes and contained immunosuppressive proteins including TGF-β, α fetoprotein and heat shock proteins. OSA exosomes directly attenuated the rate of T cell proliferation, increased a regulatory (FoxP3+) CD4+ phenotype and diminished the expression of the activation marker CD25+ on CD8+ cells. Exosomes of osteoblasts also demonstrated a direct impact on T cells, but to a lesser degree. Conclusions: Osteosarcoma-derived exosomes compared to normal osteoblasts contain an immunomodulatory cargo, which reduced the rate of T cell proliferation and promoted T regulatory phenotype. Osteoblast-derived exosomes can also reduce T cell activity, but to lesser degree compared to OSA exosomes and without promoting a T regulatory phenotype. - Highlights: • Proteomic profiles of osteoblasts and osteosarcoma exosomes have been characterized. • Malignant exosomes have immunosuppressive phenotype. • Osteosarcoma exosomes inhibit CD4{sup +} and CD8{sup +} T cell proliferation and activation. • Osteosarcoma exosomes can upregulate the expression of FOXP3 and CD25{sup +} in CD4{sup +} T cells.

60 APPLIED LIFE SCIENCES↗