Scholarly Work - Microbiology & Cell Biology

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Phytochemical Composition and Biological Activity of the Essential Oil from Ericameria nauseosa Collected in Southwestern Montana, United States
(MDPI AG, 2024-07) Schepetkin, Igor A.; Özek, Gulmira; Özek, Temel; Kirpotina, Liliya N.; Khlebnikov, Andrei I.; Ayçiçek, Kevser; Lavin, Matthew; Quinn, Mark T.
Ericameria nauseosa (Pall. ex Pursh) G.L. Nesom & G.I. Baird) is used in traditional medicine to treat various diseases; however, little is known about the immunomodulatory activity of essential oil from this plant. Thus, we isolated essential oil from the aerial parts of E. nauseosa and evaluated their chemical composition and biological activity. Compositional analysis of E. nauseosa essential oil revealed that the main (>2%) components were γ-decalactone (13.3%), cryptone (9.4%), terpinen-4-ol (9.3%), (E)-methyl cinnamate (6.0%), T-cadinol (4.7%), spathulenol (3.6%), 8Z-2,3-dihydromatricaria ester (3.1%), β-phellandrene (3.0%), p-cymen-8-ol (2.2%), 3-ethoxy-2-cycloocten-1-one (2.2%), and trans-p-menth-2-en-1-ol (2.1%). Distinctive features were the lactones (up to 15%) and polyacetylenes (up to 3.1%), including (2Z,8Z)-matricaria ester and 8Z-2,3-dihydromatricaria ester. A comparison with other reported E. nauseosa essential oil samples showed that our samples were distinct from those collected in other areas of the country; however, they did have the most similarity to one sample collected in North Central Utah. Pharmacological studies showed that E. nauseosa essential oil activated human neutrophil Ca2+ influx, which desensitized these cells to subsequent agonist-induced functional responses. Based on our previously reported data that nerolidol, β-pinene, spathulenol, sabinene, and γ-terpinene were active in human neutrophils, these compounds are the most likely constituents contributing to this immunomodulatory activity. However, the relatively high amount of polyacetylenes may also contribute, as these compounds have been characterized as potent immunomodulators.
Understanding phycosomal dynamics to improve industrial microalgae cultivation
(Elsevier BV, 2024-01) Miller, Isaac R.; Bui, Huyen; Wood, Jessica B.; Fields, Matthew W.; Gerlach, Robin
Algal–bacterial interactions are ubiquitous in both natural and industrial systems, and the characterization of these interactions has been reinvigorated by potential applications in biosystem productivity. Different growth conditions can be used for operational functions, such as the use of low-quality water or high pH/alkalinity, and the altered operating conditions likely constrain microbial community structure and function in unique ways. However, research is necessary to better understand whether consortia can be designed to improve the productivity, processing, and sustainability of industrial-scale cultivations through different controls that can constrain microbial interactions for maximal light-driven outputs. The review highlights current knowledge and gaps for relevant operating conditions, as well as suggestions for near-term and longer-term improvements for large-scale cultivation and polyculture engineering.
Anti-Inflammatory Activity of Pyrazolo[1,5-a]quinazolines
(MDPI AG, 2024-05) Crocetti, Letizia; Khlebnikov, Andrei I.; Guerrini, Gabriella; Schepetkin, Igor A.; Melani, Fabrizio; Giovannoni, Maria Paola; Quinn, Mark T.
Chronic inflammation contributes to a number of diseases. Therefore, control of the inflammatory response is an important therapeutic goal. To identify novel anti-inflammatory compounds, we synthesized and screened a library of 80 pyrazolo[1,5-a]quinazoline compounds and related derivatives. Screening of these compounds for their ability to inhibit lipopolysaccharide (LPS)-induced nuclear factor κB (NF-κB) transcriptional activity in human THP-1Blue monocytic cells identified 13 compounds with anti-inflammatory activity (IC50 < 50 µM) in a cell-based test system, with two of the most potent being compounds 13i (5-[(4-sulfamoylbenzyl)oxy]pyrazolo[1,5-a]quinazoline-3-carboxamide) and 16 (5-[(4-(methylsulfinyl)benzyloxy]pyrazolo[1,5-a]quinazoline-3-carboxamide). Pharmacophore mapping of potential targets predicted that 13i and 16 may be ligands for three mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase 2 (ERK2), p38α, and c-Jun N-terminal kinase 3 (JNK3). Indeed, molecular modeling supported that these compounds could effectively bind to ERK2, p38α, and JNK3, with the highest complementarity to JNK3. The key residues of JNK3 important for this binding were identified. Moreover, compounds 13i and 16 exhibited micromolar binding affinities for JNK1, JNK2, and JNK3. Thus, our results demonstrate the potential for developing lead anti-inflammatory drugs based on the pyrazolo[1,5-a]quinazoline and related scaffolds that are targeted toward MAPKs.
Repair of CRISPR-guided RNA breaks enables site-specific RNA excision in human cells
(American Association for the Advancement of Science, 2024) Nemudraia, Anna; Nemudryi, Artem; Wiedenheft, Blake
Genome editing with CRISPR RNA-guided endonucleases generates DNA breaks that are resolved by cellular DNA repair machinery. However, analogous methods to manipulate RNA remain unavailable. We show that site-specific RNA breaks generated with type-III CRISPR complexes are repaired in human cells and that this repair can be used for programmable deletions in human transcripts to restore gene function. Collectively, this work establishes a technology for precise RNA manipulation with potential therapeutic applications.
The primate cortical LFP exhibits multiple spectral and temporal gradients and widespread task dependence during visual short-term memory
(American Physiological Society, 2024-06) Hoffman, Steven J.; Dotson, Nicholas M.; Lma, Vinicius; Gray, Charles M.
Although cognitive functions are hypothesized to be mediated by synchronous neuronal interactions in multiple frequency bands among widely distributed cortical areas, we still lack a basic understanding of the distribution and task dependence of oscillatory activity across the cortical map. Here, we ask how the spectral and temporal properties of the local field potential (LFP) vary across the primate cerebral cortex, and how they are modulated during visual short-term memory. We measured the LFP from 55 cortical areas in two macaque monkeys while they performed a visual delayed match to sample task. Analysis of peak frequencies in the LFP power spectra reveals multiple discrete frequency bands between 3 and 80 Hz that differ between the two monkeys. The LFP power in each band, as well as the sample entropy, a measure of signal complexity, display distinct spatial gradients across the cortex, some of which correlate with reported spine counts in cortical pyramidal neurons. Cortical areas can be robustly decoded using a small number of spectral and temporal parameters, and significant task-dependent increases and decreases in spectral power occur in all cortical areas. These findings reveal pronounced, widespread, and spatially organized gradients in the spectral and temporal activity of cortical areas. Task-dependent changes in cortical activity are globally distributed, even for a simple cognitive task.
The Diverse Evolutionary Histories of Domesticated Metaviral Capsid Genes in Mammals
(Oxford University Press, 2024-04) Henriques, William S.; Young, Janet M.; Nemudryi, Artem; Nemudraia, Anna
Selfish genetic elements comprise significant fractions of mammalian genomes. In rare instances, host genomes domesticate segments of these elements for function. Using a complete human genome assembly and 25 additional vertebrate genomes, we re-analyzed the evolutionary trajectories and functional potential of capsid (CA) genes domesticated from Metaviridae, a lineage of retrovirus-like retrotransposons. Our study expands on previous analyses to unearth several new insights about the evolutionary histories of these ancient genes. We find that at least five independent domestication events occurred from diverse Metaviridae, giving rise to three universally retained single-copy genes evolving under purifying selection and two gene families unique to placental mammals, with multiple members showing evidence of rapid evolution. In the SIRH/RTL family, we find diverse amino-terminal domains, widespread loss of protein-coding capacity in RTL10 despite its retention in several mammalian lineages, and differential utilization of an ancient programmed ribosomal frameshift in RTL3 between the domesticated CA and protease domains. Our analyses also reveal that most members of the PNMA family in mammalian genomes encode a conserved putative amino-terminal RNA-binding domain (RBD) both adjoining and independent from domesticated CA domains. Our analyses lead to a significant correction of previous annotations of the essential CCDC8 gene. We show that this putative RBD is also present in several extant Metaviridae, revealing a novel protein domain configuration in retrotransposons. Collectively, our study reveals the divergent outcomes of multiple domestication events from diverse Metaviridae in the common ancestor of placental mammals.
A concept for international societally relevant microbiology education and microbiology knowledge promulgation in society
(Wiley, 2024-05) Timmis, Kenneth et al.; Boyd, Eric S.
Sulfide oxidation by members of the Sulfolobales
(Oxford University Press, 2024-05) Fernandes-Martins, Maria C.; Colman, Daniel R.; Boyd, Eric S.
The oxidation of sulfur compounds drives the acidification of geothermal waters. At high temperatures (>80°C) and in acidic conditions (pH <6.0), oxidation of sulfide has historically been considered an abiotic process that generates elemental sulfur (S0) that, in turn, is oxidized by thermoacidophiles of the model archaeal order Sulfolobales to generate sulfuric acid (i.e. sulfate and protons). Here, we describe five new aerobic and autotrophic strains of Sulfolobales comprising two species that were isolated from acidic hot springs in Yellowstone National Park (YNP) and that can use sulfide as an electron donor. These strains significantly accelerated the rate and extent of sulfide oxidation to sulfate relative to abiotic controls, concomitant with production of cells. Yields of sulfide-grown cultures were ∼2-fold greater than those of S0-grown cultures, consistent with thermodynamic calculations indicating more available energy in the former condition than the latter. Homologs of sulfide:quinone oxidoreductase (Sqr) were identified in nearly all Sulfolobales genomes from YNP metagenomes as well as those from other reference Sulfolobales, suggesting a widespread ability to accelerate sulfide oxidation. These observations expand the role of Sulfolobales in the oxidative sulfur cycle, the geobiological feedbacks that drive the formation of acidic hot springs, and landscape evolution.
Naegleria fowleri Detected in Grand Teton National Park Hot Springs
(American Chemical Society, 2024-01) Barnhart, Elliot P.; Kinsey, Stacey M.; Wright, Peter R.; Caldwell, Sara L.; Hill, Vince; Kahler, Amy; Mattioli, Mia; Cornman, Robert S.; Iwanowicz, Deborah; Eddy, Zachary; Halonen, Sandra; Mueller, Rebecca; Peyton, Brent M.; Puzon, Geoffrey J.
The free-living thermophilic amoeba Naegleria fowleri (N. fowleri) causes the highly fatal disease primary amoebic meningoencephalitis. The environmental conditions that are favorable to the growth and proliferation of N. fowleri are not well-defined, especially in northern regions of the United States. In this study, we used culture-based methods and multiple molecular approaches to detect and analyzeN. fowleri and other Naegleria spp. in water, sediment, and biofilm samples from five hot spring sites in Grand Teton National Park, Wyoming, U.S.A. These results provide the first detections of N. fowleri in Grand Teton National Park and provide new insights into the distribution of pathogenic N. fowleri and other nonpathogenic Naegleria spp. in natural thermal water systems in northern latitudes.
Hydrophobic residues in S1 modulate enzymatic function and voltage sensing in voltage-sensing phosphatase
(Rockefeller University Press, 2024-05) Rayaprolu, Vamseedhar; Miettinen, Heini M.; Baker, William D.; Young, Victoria C.; Fisher, Matthew; Mueller, Gwendolyn; Rankin, William O.; Kelley, John T.; Ratzan, William J.; Leong, Lee Min; Davisson, Joshua A.; Baker, Bradley J.; Kohout, Susy C.
The voltage-sensing domain (VSD) is a four-helix modular protein domain that converts electrical signals into conformational changes, leading to open pores and active enzymes. In most voltage-sensing proteins, the VSDs do not interact with one another, and the S1–S3 helices are considered mainly scaffolding, except in the voltage-sensing phosphatase (VSP) and the proton channel (Hv). To investigate its contribution to VSP function, we mutated four hydrophobic amino acids in S1 to alanine (F127, I131, I134, and L137), individually or in combination. Most of these mutations shifted the voltage dependence of activity to higher voltages; however, not all substrate reactions were the same. The kinetics of enzymatic activity were also altered, with some mutations significantly slowing down dephosphorylation. The voltage dependence of VSD motions was consistently shifted to lower voltages and indicated a second voltage-dependent motion. Additionally, none of the mutations broke the VSP dimer, indicating that the S1 impact could stem from intra- and/or intersubunit interactions. Lastly, when the same mutations were introduced into a genetically encoded voltage indicator, they dramatically altered the optical readings, making some of the kinetics faster and shifting the voltage dependence. These results indicate that the S1 helix in VSP plays a critical role in tuning the enzyme’s conformational response to membrane potential transients and influencing the function of the VSD.
Ebselen analogues with dual human neutrophil elastase (HNE) inhibitory and antiradical activity
(Royal Society of Chemistry, 2024-01) Crocetti, Letizia; Catarzi, Francesca; Giovannoni, Maria Paola; Vergelli, Claudia; Bartolucci, Gianluca; Pallecchi, Marco; Paoli, Paola; Rossi, Patrizia; Lippi, Martina; Schepetkin, Igor A.; Quinn, Mark T.; Guerrini, Gabriella
Human neutrophil elastase (HNE) plays an essential role in host defense against bacteria but is also involved in several respiratory diseases. Recent reports suggest that compounds exhibiting a combination of HNE inhibitory activity with antiradical properties may be therapeutically beneficial for the treatment of respiratory diseases involving inflammation and oxidative stress. We report here the synthesis and biological evaluation of novel ebselen analogues exhibiting HNE inhibitory and antiradical activities. HNE inhibition was evaluated in an enzymatic system using human HNE, whereas antiradical activity was evaluated in a cell-based assay system using phorbol 12-myristate 13-acetate (PMA)-stimulated murine bone marrow leukocytes as the source of reactive oxygen species (ROS). HNE inhibition was due to the N–CO group targeting Ser195-OH at position 2 of the scaffold, while antiradical activity was due to the presence of the selenium atom. The most active compounds 4d, 4f, and 4j exhibited a good balance between anti-HNE (IC50 = 0.9–1.4 μM) and antiradical activity (IC50 = 0.05–0.7 μM). Additionally, the solid-state structure of 4d was determined and compared to that of the similar compound N-propionyl-1,2-benzisoselenazol-3(2H)-one.
Osteochondral fluid transport in an ex vivo system
(Elsevier BV, 2024-04) Hislop, Brady David; Mercer, Ara K.; Whitley, Alexandria G.; Myers, Erik P.; Mackin, Marie; Heveran, Chelsea M.; June, Ronald K.
Objective: Alterations to bone-to-cartilage fluid transport may contribute to the development of osteoarthritis (OA). Larger biological molecules in bone may transport from bone-to-cartilage (e.g., insulin, 5 kDa). However, many questions remain about fluid transport between these tissues. The objectives of this study were to (1) test for diffusion of 3 kDa molecular tracers from bone-to-cartilage and (2) assess potential differences in bone-to-cartilage fluid transport between different loading conditions. Design: Osteochondral cores extracted from bovine femurs (N = 10 femurs, 10 cores/femur) were subjected to either no-load (i.e., pure diffusion), pre-load only, or cyclic compression (5 ± 2% or 10 ± 2% strain) in a two-chamber bioreactor. The bone was placed into the bone compartment followed by a 3 kDa dextran tracer, and tracer concentrations in the cartilage compartment were measured every 5 min for 120 min. Tracer concentrations were analyzed for differences in beginning, peak, and equilibrium concentrations, loading effects, and time-to-peak tracer concentration. Results: Peak tracer concentration in the cartilage compartment was significantly higher compared to the beginning and equilibrium tracer concentrations. Cartilage-compartment tracer concentration and maximum fluorescent intensity were influenced by strain magnitude. No time-to-peak relationship was found between strain magnitudes and cartilage-compartment tracer concentration. Conclusion: This study shows that bone-to-cartilage fluid transport occurs with 3 kDa dextran molecules. These are larger molecules to move between bone and cartilage than previously reported. Further, these results demonstrate the potential impact of cyclic compression on osteochondral fluid transport. Determining the baseline osteochondral fluid transport in healthy tissues is crucial to elucidating the mechanisms OA pathology.
Respiratory viruses: New frontiers—a Keystone Symposia report
(Wiley, 2023-02) Cable, Jennifer et al.; Thomas, Mallory M.
Respiratory viruses are a common cause of morbidity and mortality around the world. Viruses like influenza, RSV, and most recently SARS-CoV-2 can rapidly spread through a population, causing acute infection and, in vulnerable populations, severe or chronic disease. Developing effective treatment and prevention strategies often becomes a race against ever-evolving viruses that develop resistance, leaving therapy efficacy either short-lived or relevant for specific viral strains. On June 29 to July 2, 2022, researchers met for the Keystone symposium “Respiratory Viruses: New Frontiers.” Researchers presented new insights into viral biology and virus–host interactions to understand the mechanisms of disease and identify novel treatment and prevention approaches that are effective, durable, and broad.
Volatile Composition, Antimicrobial Activity, and In Vitro Innate Immunomodulatory Activity of Echinacea purpurea (L.) Moench Essential Oils
(MDPI AG, 2023-10) Dosoky, Noura S.; Kirpotina, Liliya N.; Schepetkin, Igor A.; Khlebnikov, Andrei I.; Lisonbee, Brent L.; Black, Jeffrey L.; Woolf, Hillary; Thurgood, Trever L.; Graf, Brittany L.; Satyal, Prabodh; Quinn, Mark T.
Echinacea purpurea (L.) Moench is a medicinal plant commonly used for the treatment of upper respiratory tract infections, the common cold, sore throat, migraine, colic, stomach cramps, and toothaches and the promotion of wound healing. Based on the known pharmacological properties of essential oils (EOs), we hypothesized that E. purpurea EOs may contribute to these medicinal properties. In this work, EOs from the flowers of E. purpurea were steam-distilled and analyzed by gas chromatography–mass spectrometry (GC–MS), GC with flame-ionization detection (GC–FID), and chiral GC–MS. The EOs were also evaluated for in vitro antimicrobial and innate immunomodulatory activity. About 87 compounds were identified in five samples of the steam-distilled E. purpurea EO. The major components of the E. purpurea EO were germacrene D (42.0 ± 4.61%), α-phellandrene (10.09 ± 1.59%), β-caryophyllene (5.75 ± 1.72%), γ-curcumene (5.03 ± 1.96%), α-pinene (4.44 ± 1.78%), δ-cadinene (3.31 ± 0.61%), and β-pinene (2.43 ± 0.98%). Eleven chiral compounds were identified in the E. purpurea EO, including α-pinene, sabinene, β-pinene, α-phellandrene, limonene, β-phellandrene, α-copaene, β-elemene, β-caryophyllene, germacrene D, and δ-cadinene. Analysis of E. purpurea EO antimicrobial activity showed that they inhibited the growth of several bacterial species, although the EO did not seem to be effective for Staphylococcus aureus. The E. purpurea EO and its major components induced intracellular calcium mobilization in human neutrophils. Additionally, pretreatment of human neutrophils with the E. purpurea EO or (+)-δ-cadinene suppressed agonist-induced neutrophil calcium mobilization and chemotaxis. Moreover, pharmacophore mapping studies predicted two potential MAPK targets for (+)-δ-cadinene. Our results are consistent with previous reports on the innate immunomodulatory activities of β-caryophyllene, α-phellandrene, and germacrene D. Thus, this study identified δ-cadinene as a novel neutrophil agonist and suggests that δ-cadinene may contribute to the reported immunomodulatory activity of E. purpurea.
Antiviral responses in a Jamaican fruit bat intestinal organoid model of SARS-CoV-2 infection
(Springer Science and Business Media LLC, 2023-10) Hashimi, Marziah; Sebrell, T. Andrew; Hedges, Jodi F.; Snyder, Deann; Lyon, Katrina N.; Byrum, Stephanie D.; Mackintosh, Samuel G.; Crowley, Dan; Cherne, Michelle D.; Skwarchuk, David; Robison, Amanda; Sidar, Barkan; Kunze, Anja; Loveday, Emma K.; Taylor, Matthew P.; Chang, Connie B.; Wilking, James N.; Walk, Seth T.; Schountz, Tony; Jutila, Mark A.; Bimczok, Diane
Bats are natural reservoirs for several zoonotic viruses, potentially due to an enhanced capacity to control viral infection. However, the mechanisms of antiviral responses in bats are poorly defined. Here we established a Jamaican fruit bat (JFB, Artibeus jamaicensis) intestinal organoid model of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Upon infection with SARS-CoV-2, increased viral RNA and subgenomic RNA was detected, but no infectious virus was released, indicating that JFB organoids support only limited viral replication but not viral reproduction. SARS-CoV-2 replication was associated with significantly increased gene expression of type I interferons and inflammatory cytokines. Interestingly, SARS-CoV-2 also caused enhanced formation and growth of JFB organoids. Proteomics revealed an increase in inflammatory signaling, cell turnover, cell repair, and SARS-CoV-2 infection pathways. Collectively, our findings suggest that primary JFB intestinal epithelial cells mount successful antiviral interferon responses and that SARS-CoV-2 infection in JFB cells induces protective regenerative pathways.
Discovering unknown associations between prokaryotic receptors and their ligands
(Proceedings of the National Academy of Sciences, 2023-11) Dlakić, Mensur
The motility of microorganisms through the environment is driven by chemical gradients: They move towards nutrients and away from signals that indicate unfavorable conditions. This chemotaxis is mediated by transmembrane chemoreceptors that recognize one or many target molecules. In most cases, the encounter with a ligand is recorded by a periplasmic sensor domain, which in turn transmits a signal through the membrane to a cytoplasmic signaling domain (1). Under conditions of environmental stress, these signaling cascades may induce profound lifestyle changes from planktonic cells to a biofilm or from active to inactive cells (2). While it is relatively straightforward to annotate most prokaryotic chemoreceptors from the ever-increasing number of sequenced genomes and environmental samples, the identity of their binding partners is often not clear from protein sequence. As the specificity of downstream signaling events is determined by the sensor domain, it is critical to learn about novel pairings between ligands and their receptors. Using a range of computational and experimental approaches, Cerna-Vargas et al. show in PNAS that a subset of a wide-spread group of dCache_1 receptors evolved to recognize various types of biological amines.
Genome sequence, phylogenetic analysis, and structure-based annotation reveal metabolic potential of Chlorella sp. SLA-04
(Elsevier BV, 2023-01) Goemann, Calvin L.C.; Wilkinson, Royce; Henriques, William; Bui, Huyen; Goemann, Hannah M.; Carlson, Ross P.; Viamajala, Sridhar; Gerlach, Robin; Wiedenheft, Blake
Algae are a broad class of photosynthetic eukaryotes that are phylogenetically and physiologically diverse. Most of the phylogenetic diversity has been inferred from 18S rDNA sequencing since there are only a few complete genomes available in public databases. Here we use ultra-long-read Nanopore sequencing to determine a gapless, telomere-to-telomere complete genome sequence of Chlorella sp. SLA-04, previously described as Chlorella sorokiniana SLA-04. Chlorella sp. SLA-04 is a green alga that grows to high cell density in a wide variety of environments – high and neutral pH, high and low alkalinity, and high and low salinity. SLA-04's ability to grow in high pH and high alkalinity media without external CO2 supply is favorable for large-scale algal biomass production. Phylogenetic analysis performed using ribosomal DNA and conserved protein sequences consistently reveal that Chlorella sp. SLA-04 forms a distinct lineage from other strains of Chlorella sorokiniana. We complement traditional genome annotation methods with high throughput structural predictions and demonstrate that this approach expands functional prediction of the SLA-04 proteome. Genomic analysis of the SLA-04 genome identifies the genes capable of utilizing TCA cycle intermediates to replenish cytosolic acetyl-CoA pools for lipid production. We also identify a complete metabolic pathway for sphingolipid anabolism that may allow SLA-04 to readily adapt to changing environmental conditions and facilitate robust cultivation in mass production systems. Collectively, this work clarifies the phylogeny of Chlorella sp. SLA-04 within Trebouxiophyceae and demonstrates how structural predictions can be used to improve annotation beyond sequence-based methods.
Development of potent isoflavone-based formyl peptide receptor 1 (FPR1) antagonists and their effects in gastric cancer cell models
(Elsevier BV, 2023-12) Francavilla, Fabio; Sarcina, Federica; Schepetkin, Igor A.; Kirpotina, Lilya N.; Contino, Marialessandra; Schirizzi, Annalisa; De Leonardis, Giampiero; Khlebnikov, Andrei I.; D'Alessandro, Rosalba; Quinn, Mark T.; Lacivita, Enza; Leopoldo, Marcello
Formyl peptide receptor-1 (FPR1) is a G protein-coupled chemoattractant receptor that plays a crucial role in the trafficking of leukocytes into the sites of bacterial infection and inflammation. Recently, FPR1 was shown to be expressed in different types of tumor cells and could play a significant role in tumor growth and invasiveness. Starting from the previously reported FPR1 antagonist 4, we have designed a new series of 4H-chromen-2-one derivatives that exhibited a substantial increase in FPR1 antagonist potency. Docking studies identified the key interactions for antagonist activity. The most potent compounds in this series (24a and 25b) were selected to study the effects of the pharmacological blockade of FPR1 in NCl–N87 and AGS gastric cancer cells. Both compounds potently inhibited cell growth through a combined effect on cell proliferation and apoptosis and reduced cell migration, while inducing an increase in angiogenesis, thus suggesting that FPR1 could play a dual role as oncogene and onco-suppressor.
Neuroprotective Effects of Tryptanthrin-6-Oxime in a Rat Model of Transient Focal Cerebral Ischemia
(MDPI AG, 2023-07) Plotnikov, Mark B.; Chernysheva, Galina A.; Smol’yakova, Vera I.; Aliev, Oleg I.; Anishchenko, Anna M.; Ulyakhina, Olga A.; Trofimova, Eugene S.; Ligacheva, Anastasia A.; Anfinogenova, Nina D.; Osipenko, Anton N.; Kovrizhina, Anastasia R.; Khlebnikov, Andrei I.; Schepetkin, Igor A.; Drozd, Anastasia G.; Plotnikov, Evgenii V.; Atochin, Dmitriy N.; Quinn, Mark T.
The activation of c-Jun N-terminal kinase (JNK) plays an important role in stroke outcomes. Tryptanthrin-6-oxime (TRYP-Ox) is reported to have high affinity for JNK and anti-inflammatory activity and may be of interest as a promising neuroprotective agent. The aim of this study was to investigate the neuroprotective effects of TRYP-Ox in a rat model of transient focal cerebral ischemia (FCI), which involved intraluminal occlusion of the left middle cerebral artery (MCA) for 1 h. Animals in the experimental group were administered intraperitoneal injections of TRYP-Ox 30 min before reperfusion and 23 and 47 h after FCI. Neurological status was assessed 4, 24, and 48 h following FCI onset. Treatment with 5 and 10 mg/kg of TRYP-Ox decreased mean scores of neurological deficits by 35–49 and 46–67% at 24 and 48 h, respectively. At these doses, TRYP-Ox decreased the infarction size by 28–31% at 48 h after FCI. TRYP-Ox (10 mg/kg) reduced the content of interleukin (IL) 1β and tumor necrosis factor (TNF) in the ischemic core area of the MCA region by 33% and 38%, respectively, and attenuated cerebral edema by 11% in the left hemisphere, which was affected by infarction, and by 6% in the right, contralateral hemisphere 24 h after FCI. TRYP-Ox reduced c-Jun phosphorylation in the MCA pool at 1 h after reperfusion. TRYP-Ox was predicted to have high blood–brain barrier permeability using various calculated descriptors and binary classification trees. Indeed, reactive oxidant production was significantly lower in the brain homogenates from rats treated with TRYP-Ox versus that in control animals. Our data suggest that the neuroprotective activity of TRYP-Ox may be due to the ability of this compound to inhibit JNK and exhibit anti-inflammatory and antioxidant activity. Thus, TRYP-Ox may be considered a promising neuroprotective agent that potentially could be used for the development of new treatment strategies in cerebral ischemia.
Immunomodulatory Activity of Polysaccharides Isolated from Saussurea salicifolia L. and Saussurea frolovii Ledeb
(MDPI AG, 2023-09) Schepetkin, Igor A.; Danilets, Marina G.; Ligacheva, Anastasia A.; Trofimova, Evgenia S.; Selivanova, Natalia S.; Sherstoboev, Evgenii Yu.; Krivoshchekov, Sergei V.; Gulina, Ekaterina I.; Brazovskii, Konstantin S.; Kirpotina, Liliya N.; Quinn, Mark T.; Belousov, Mikhail V.
The genus Saussurea has been used in the preparation of therapies for a number of medical problems, yet not much is known about the therapeutic high-molecular-weight compounds present in extracts from these plants. Since polysaccharides are important in immune modulation, we investigated the chemical composition and immunomodulatory activity of Saussurea salicifolia L. and Saussurea frolovii Ledeb polysaccharides. Water-soluble polysaccharides from the aerial parts of these plants were extracted using water at pHs of 2 and 6 and subsequently precipitated in ethanol to obtain fractions SSP2 and SSP6 from S. salicifolia and fractions SSF2 and SSF6 from S. frolovii. The molecular weights of fractions SSP2, SSP6, SFP2, and SFP6 were estimated to be 143.7, 113.2, 75.3, and 64.3 kDa, respectively. The polysaccharides from S. frolovii contained xylose (67.1–71.7%) and glucose (28.3–32.9%), whereas the polysaccharides from S. frolovii contained xylose (63.1–76.7%), glucose (11.8–19.2%), galactose (4.7–8.3%), and rhamnose (6.8–9.4%). Fractions SSP2, SSP6, and SFP2 stimulated nitric oxide (NO) production by murine macrophages, and NO production induced by SSP2, SSP6, and SFP2 was not inhibited by polymyxin B treatment of the fractions, whereaspolymyxin B treatment diminished the effects of SFP6, suggesting that SFP6 could contain lipopolysaccharide (LPS). The LPS-free fractions SSP2, SSP6, and SFP2 had potent immunomodulatory activity, induced NO production, and activated transcription factors NF-κB/AP-1 in human monocytic THP-1 cells and cytokine production by human MonoMac-6 monocytic cells, including interleukin (IL)-1α, IL-1β, IL-6, granulocyte macrophage colony-stimulating factor (GM-CSF), interferon-γ, monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor (TNF). These data suggest that at least part of the beneficial therapeutic effects reported for water extracts of the Saussurea species are due to the modulation of leukocyte functions by polysaccharides.

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