Microbiology & Cell Biology
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Item Neutrophil Immunomodulatory Activity of Farnesene, a Component of Artemisia dracunculus Essential Oils(MDPI AG, 2022-05) Schepetkin, Igor A.; Özek, Gulmira; Özek, Temel; Kirpotina, Liliya N.; Khlebnikov, Andrei I.; Klein, Robyn A.; Quinn, Mark T.Despite their reported therapeutic properties, not much is known about the immunomodulatory activity of essential oils present in Artemisia species. We isolated essential oils from the flowers and leaves of five Artemisia species: A. tridentata, A. ludoviciana, A. dracunculus, A. frigida, and A. cana. The chemical composition of the Artemisia essential oil samples had similarities and differences as compared to those previously reported in the literature. The main components of essential oils obtained from A. tridentata, A. ludoviciana, A. frigida, and A. cana were camphor (23.0–51.3%), 1,8-cineole (5.7–30.0%), camphene (1.6–7.7%), borneol (2.3–14.6%), artemisiole (1.2–7.5%), terpinen-4-ol (2.0–6.9%), α-pinene (0.8–3.9%), and santolinatriene (0.7–3.5%). Essential oils from A. dracunculus were enriched in methyl chavicol (38.8–42.9%), methyl eugenol (26.1–26.4%), terpinolene (5.5–8.8%), (E/Z)-β-ocimene (7.3–16.0%), β-phellandrene (1.3–2.2%), p-cymen-8-ol (0.9–2.3%), and xanthoxylin (1.2–2.2%). A comparison across species also demonstrated that some compounds were present in only one Artemisia species. Although Artemisia essential oils were weak activators of human neutrophils, they were relatively more potent in inhibiting subsequent neutrophil Ca2+ mobilization with N-formyl peptide receptor 1 (FPR1) agonist fMLF- and FPR2 agonist WKYMVM, with the most potent being essential oils from A. dracunculus. Further analysis of unique compounds found in A. dracunculus showed that farnesene, a compound with a similar hydrocarbon structure as lipoxin A4, inhibited Ca2+ influx induced in human neutrophils by fMLF (IC50 = 1.2 μM), WKYMVM (IC50 = 1.4 μM), or interleukin 8 (IC50 = 2.6 μM). Pretreatment with A. dracunculus essential oils and farnesene also inhibited human neutrophil chemotaxis induced by fMLF, suggesting these treatments down-regulated human neutrophil responses to inflammatory chemoattractants. Thus, our studies have identified farnesene as a potential anti-inflammatory modulator of human neutrophils.Item Innate Immunomodulatory Activity of Cedrol, a Component of Essential Oils Isolated from Juniperus Species(MDPI AG, 2021-12) Özek, Gulmira; Schepetkin, Igor A.; Yermagambetova, Moldir; Özek, Temel; Kirpotina, Liliya N.; Almerekova, Shyryn S.; Abugalieva, Saule I.; Khlebnikov, Andrei I.; Quinn, Mark T.Little is known about the immunomodulatory activity of essential oils isolated from Juniperus species. Thus, we isolated essential oils from the cones and leaves of eight juniper species found in Montana and in Kazakhstan, including J. horizontalis, J. scopolorum, J. communis, J. seravschanica, J. sabina, J. pseudosabina, J. pseudosabina subsp. turkestanica, and J. sibirica. We report here the chemical composition and innate immunomodulatory activity of these essential oils. Compositional analysis of the 16 samples of Juniper essential oils revealed similarities and differences between our analyses and those previously reported for essential oils from this species. Our studies represent the first analysis of essential oils isolated from the cones of four of these Juniper species. Several essential oil samples contained high levels of cedrol, which was fairly unique to three Juniper species from Kazakhstan. We found that these essential oils and pure (+)-cedrol induced intracellular Ca2+ mobilization in human neutrophils. Furthermore, pretreatment of human neutrophils and N-formyl peptide receptor 1 and 2 (FPR1 and FPR2) transfected HL60 cells with these essential oils or (+)-cedrol inhibited agonist-induced Ca2+ mobilization, suggesting these responses were desensitized by this pretreatment. In support of this conclusion, pretreatment with essential oils from J. seravschanica cones (containing 16.8% cedrol) or pure (+)-cedrol inhibited human neutrophil chemotaxis to N-formyl peptide. Finally, reverse pharmacophore mapping predicted several potential kinase targets for cedrol. Thus, our studies have identified cedrol as a novel neutrophil agonist that can desensitize cells to subsequent stimulation by N-formyl peptide.Item Novel c-Jun N-Terminal Kinase (JNK) Inhibitors with an 11H-Indeno[1,2-b]quinoxalin-11-one Scaffold(MDPI AG, 2021-09) Liakhov, Serhii A.; Schepetkin, Igor A.; Karpenko, Olexander S.; Duma, Hanna I.; Haidarzhy, Nadiia M.; Kirpotina, Liliya N.; Kovrizhina, Anastasia R.; Khlebnikov, Andrei I.; Bagryanskaya, Irina Y.; Quinn, Mark T.c-Jun N-terminal kinase (JNK) plays a central role in stress signaling pathways implicated in important pathological processes, including rheumatoid arthritis and ischemia-reperfusion injury. Therefore, inhibition of JNK is of interest for molecular targeted therapy to treat various diseases. We synthesized 13 derivatives of our reported JNK inhibitor 11H-indeno[1,2-b]quinoxalin-11-one oxime and evaluated their binding to the three JNK isoforms and their biological effects. Eight compounds exhibited submicromolar binding affinity for at least one JNK isoform. Most of these compounds also inhibited lipopolysaccharide (LPS)-induced nuclear factor-κB/activating protein 1 (NF-κB/AP-1) activation and interleukin-6 (IL-6) production in human monocytic THP1-Blue cells and human MonoMac-6 cells, respectively. Selected compounds (4f and 4m) also inhibited LPS-induced c-Jun phosphorylation in MonoMac-6 cells, directly confirming JNK inhibition. We conclude that indenoquinoxaline-based oximes can serve as specific small-molecule modulators for mechanistic studies of JNKs, as well as potential leads for the development of anti-inflammatory drugs.Item Therapeutic Effect of Novel Cyanopyrrolidine-Based Prolyl Oligopeptidase Inhibitors in Rat Models of Amnesia(Frontiers Media SA, 2021-12) Zolotov, Nikolay N.; Schepetkin, Igor A.; Voronina, Tatyana A.; Pozdnev, Vladimir F.; Khlebnikov, Andrei I.; Krylova, Irina V.; Quinn, Mark T.Prolyl oligopeptidase (POP) is a large cytosolic serine peptidase that is altered in patients with Alzheimer’s disease, Parkinsonian syndrome, muscular dystrophies, and other denervating diseases. Thus, POP may represent a relevant therapeutic target for treatment of neuropsychiatric disorders and neurodegenerative diseases. Here, we report the characterization of five novel cyanopyrrolidine-based compounds (BocTrpPrdN, BocGlyPrdN, CbzMetPrdN, CbzGlnPrdN, and CbzAlaPrdN) and show that they are potent inhibitors of POP and are predicted to penetrate the blood-brain barrier (BBB). Indeed, we show that CbzMetPrdN penetrates the rat BBB and effectively inhibits POP in the brain when administered intraperitoneally. Furthermore, molecular modeling confirmed these compounds likely inhibit POP via interaction with the POP catalytic site. We evaluated protective effects of the cyanopyrrolidine-based POP inhibitors using scopolamine- and maximal electroshock-induced models of amnesia in rats and showed that BocTrpPrdN, BocGlyPrdN, CbzMetPrdN, and CbzGlnPrdN significantly prolonged conditioned passive avoidance reflex (CPAR) retention time when administered intraperitoneally (1 and 2 mg/kg) before evaluation in both models of amnesia, although CbzAlaPrdN was not effective in scopolamine-induced amnesia. Our data support previous reports on the antiamnesic effects of prolinal-based POP inhibitors and indicate an important role of POP in the regulation of learning and memory processes in the CNS.Item Vaginal microbiota of American Indian women and associations with measures of psychosocial stress(Public Library of Science, 2021-12) Borgogna, Joanna-Lynn C.; Anastario, Michael; Firemoon, Paula; Rink, Elizabeth; Ricker, Adriann; Ravel, Jacques; Brotman, Rebecca M.; Yeoman, Carl J.Molecular-bacterial vaginosis (BV) is characterized by low levels of vaginal Lactobacillus species and is associated with higher risk of sexually transmitted infections (STI). Perceived psychosocial stress is associated with increased severity and persistence of infections, including STIs. American Indians have the highest rates of stress and high rates of STIs. The prevalence of molecular-BV among American Indian women is unknown. We sought to evaluate measures of psychosocial stress, such as historic loss (a multigenerational factor involving slavery, forced removal from one’s land, legally ratified race-based segregation, and contemporary discrimination) and their association with the vaginal microbiota and specific metabolites associated with BV, in 70 Northwestern Plains American Indian women. Demographics, perceived psychosocial stressors, sexual practices, and known BV risk factors were assessed using a modified version of the American Indian Service Utilization, Psychiatric Epidemiology, Risk and Protective Factors Project survey. Self-collected mid-vaginal swabs were profiled for bacterial composition by 16S rRNA gene amplicon sequencing and metabolites quantified by targeted liquid-chromatography mass spectrometry. Sixty-six percent of the participants were classified as having molecular-BV, with the rest being either dominated by L. crispatus (10%) or L. iners (24%). High levels of lifetime trauma were associated with higher odds of having molecular-BV (adjusted Odds Ratio (aOR): 2.5, 95% Credible Interval (CrI): 1.1–5.3). Measures of psychosocial stress, including historic loss and historic loss associated symptoms, were significantly associated with lifestyle and behavioral practices. Higher scores of lifetime trauma were associated with increased concentrations of spermine (aFC: 3.3, 95% CrI: 1.2–9.2). Historic loss associated symptoms and biogenic amines were the major correlates of molecular-BV. Historical loss associated symptoms and lifetime trauma are potentially important underlying factors associated with BV.Item Host Lung Environment Limits Aspergillus fumigatus Germination through an SskA-Dependent Signaling Response(American Society for Microbiology, 2021-12) Kirkland, Marina E.; Stannard, McKenzie; Kowalski, Caitlin H.; Mould, Dallas; Caffrey-Carr, Alayna; Temple, Rachel M.; Ross, Brandon S.; Lofgren, Lotus A.; Stajich, Jason E.; Cramer, Robert A.; Obar, Joshua J.Aspergillus fumigatus isolates display significant heterogeneity in growth, virulence, pathology, and inflammatory potential in multiple murine models of invasive aspergillosis. Previous studies have linked the initial germination of a fungal isolate in the airways to the inflammatory and pathological potential, but the mechanism(s) regulating A. fumigatus germination in the airways is unresolved. To explore the genetic basis for divergent germination phenotypes, we utilized a serial passaging strategy in which we cultured a slow germinating strain (AF293) in a murine-lung-based medium for multiple generations. Through this serial passaging approach, a strain emerged with an increased germination rate that induces more inflammation than the parental strain (herein named LH-EVOL for lung homogenate evolved). We identified a potential loss-of-function allele of Afu5g08390 (sskA) in the LH-EVOL strain. The LH-EVOL strain had a decreased ability to induce the SakA-dependent stress pathway, similar to AF293 ΔsskA and CEA10. In support of the whole-genome variant analyses, sskA, sakA, or mpkC loss-of-function strains in the AF293 parental strain increased germination both in vitro and in vivo. Since the airway surface liquid of the lungs contains low glucose levels, the relationship of low glucose concentration on germination of these mutant AF293 strains was examined; interestingly, in low glucose conditions, the sakA pathway mutants exhibited an enhanced germination rate. In conclusion, A. fumigatus germination in the airways is regulated by SskA through the SakA mitogen-activated protein kinase (MAPK) pathway and drives enhanced disease initiation and inflammation in the lungs.Item Comparison of Preservation and Extraction Methods on Five Taxonomically Disparate Coral Microbiomes(Frontiers Media SA, 2021-07) Pratte, Zoe A.; Kellogg, Christina A.All animals are host to a multitude of microorganisms that are essential to the animal’s health. Host-associated microbes have been shown to defend against potential pathogens, provide essential nutrients, interact with the host’s immune system, and even regulate mood. However, it can be difficult to preserve and obtain nucleic acids from some host-associated microbiomes, making studying their microbial communities challenging. Corals are an example of this, in part due to their potentially remote, underwater locations, their thick surface mucopolysaccharide layer, and various inherent molecular inhibitors. This study examined three different preservatives (RNAlater, DNA/RNA Shield, and liquid nitrogen) and two extraction methods (the Qiagen PowerBiofilm kit and the Promega Maxwell RBC kit with modifications) to determine if there was an optimum combination for examining the coral microbiome. These methods were employed across taxonomically diverse coral species, including deep-sea/shallow, stony/soft, and zooxanthellate/azooxanthellate: Lophelia pertusa, Paragorgia johnsoni, Montastraea cavernosa, Porites astreoides, and Stephanocoenia intersepta. Although significant differences were found between preservative types and extraction methods, these differences were subtle, and varied in nature from coral species to coral species. Significant differences between coral species were far more profound than those detected between preservative or extraction method. We suggest that the preservative types presented here and extraction methods using a bead-beating step provide enough consistency to compare coral microbiomes across various studies, as long as subtle differences in microbial communities are attributed to dissimilar methodologies. Additionally, the inclusion of internal controls such as a mock community and extraction blanks can help provide context regarding data quality, improving downstream analyses.Item Elasmobranch microbiomes: emerging patterns and implications for host health and ecology(Springer Science and Business Media LLC, 2021-09) Perry, Cameron T.; Pratte, Zoe A.; Clavere-Graciette, Ana; Ritchie, Kim B.; Hueter, Robert E.; Newton, Alisa L.; Fischer, G. Christopher; Dinsdale, Elizabeth A.; Doane, Michael P.; Wilkinson, Krystan A.; Bassos-Hull, Kim; Lyons, Kady; Dove, Alistair D. M.; Hoopes, Lisa A.; Stewart, Frank J.Elasmobranchs (sharks, skates and rays) are of broad ecological, economic, and societal value. These globally important fishes are experiencing sharp population declines as a result of human activity in the oceans. Research to understand elasmobranch ecology and conservation is critical and has now begun to explore the role of body-associated microbiomes in shaping elasmobranch health. Here, we review the burgeoning efforts to understand elasmobranch microbiomes, highlighting microbiome variation among gastrointestinal, oral, skin, and blood-associated niches. We identify major bacterial lineages in the microbiome, challenges to the field, key unanswered questions, and avenues for future work. We argue for prioritizing research to determine how microbiomes interact mechanistically with the unique physiology of elasmobranchs, potentially identifying roles in host immunity, disease, nutrition, and waste processing. Understanding elasmobranch–microbiome interactions is critical for predicting how sharks and rays respond to a changing ocean and for managing healthy populations in managed care.Item Unexpected diversity of Endozoicomonas in deep-sea corals(Inter-Research Science Center, 2021-09) Kellogg, Christina A.; Pratte, Zoe A.The deep ocean hosts a large diversity of azooxanthellate cold-water corals whose associated microbiomes remain to be described. While the bacterial genus Endozoicomonas has been widely identified as a dominant associate of tropical and temperate corals, it has rarely been detected in deep-sea corals. Determining microbial baselines for these cold-water corals is a critical first step to understanding the ecosystem services their microbiomes contribute, while providing a benchmark against which to measure responses to environmental change or anthropogenic effects. Samples of Acanthogorgia aspera, A. spissa, Desmophyllum dianthus, and D. pertusum (Lophelia pertusa) were collected from western Atlantic sites off the US east coast and from the northeastern Gulf of Mexico. Microbiomes were characterized by 16S rRNA gene amplicon surveys. Although D. dianthus and D. pertusum have recently been combined into a single genus due to their genetic similarity, their microbiomes were significantly different. The Acanthogorgia spp. were collected from submarine canyons in different regions, but their microbiomes were extremely similar and dominated by Endozoicomonas. This is the first report of coral microbiomes dominated by Endozoicomonas occurring below 1000 m, at temperatures near 4°C. D. pertusum from 2 Atlantic sites were also dominated by distinct Endozoicomonas, unlike D. pertusum from other sites described in previous studies, including the Gulf of Mexico, the Mediterranean Sea and a Norwegian fjord.Item Chemical Stimulants and Stressors Impact the Outcome of Virus Infection and Immune Gene Expression in Honey Bees (Apis mellifera)(Frontiers Media SA, 2021-10) Parekh, Fenali; Daughenbaugh, Katie F.; Flenniken, Michelle L.Western honey bees (Apis mellifera) are ecologically, agriculturally, and economically important plant pollinators. High average annual losses of honey bee colonies in the US have been partially attributed to agrochemical exposure and virus infections. To examine the potential negative synergistic impacts of agrochemical exposure and virus infection, as well as the potential promise of phytochemicals to ameliorate the impact of pathogenic infections on honey bees, we infected bees with a panel of viruses (i.e., Flock House virus, deformed wing virus, or Sindbis virus) and exposed to one of three chemical compounds. Specifically, honey bees were fed sucrose syrup containing: (1) thyme oil, a phytochemical and putative immune stimulant, (2) fumagillin, a beekeeper applied fungicide, or (3) clothianidin, a grower-applied insecticide. We determined that virus abundance was lower in honey bees fed 0.16 ppb thyme oil augmented sucrose syrup, compared to bees fed sucrose syrup alone. Parallel analysis of honey bee gene expression revealed that honey bees fed thyme oil augmented sucrose syrup had higher expression of key RNAi genes (argonaute-2 and dicer-like), antimicrobial peptide expressing genes (abaecin and hymenoptaecin), and vitellogenin, a putative honey bee health and age indicator, compared to bees fed only sucrose syrup. Virus abundance was higher in bees fed fumagillin (25 ppm or 75 ppm) or 1 ppb clothianidin containing sucrose syrup relative to levels in bees fed only sucrose syrup. Whereas, honey bees fed 10 ppb clothianidin had lower virus levels, likely because consuming a near lethal dose of insecticide made them poor hosts for virus infection. The negative impact of fumagillin and clothianidin on honey bee health was indicated by the lower expression of argonaute-2, dicer-like, abaecin, and hymenoptaecin, and vitellogenin. Together, these results indicate that chemical stimulants and stressors impact the outcome of virus infection and immune gene expression in honey bees.