scholarly journals MiR-4792 regulates inflammatory responses in Cryptococcus neoformans infected microglia

2020 ◽  
Author(s):  
Jianghan Chen ◽  
Guotai Yao ◽  
Xiaoli Wang ◽  
Qing Hou ◽  
Rui Gao ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Inflammatory Cytokines ◽  
Cryptococcal Meningitis ◽  
Target Gene ◽  
Inflammatory Responses ◽  
Fungal Infections ◽  
Mapk Signaling ◽  
Microbial Infection ◽  
Bv2 Cells ◽  
Infected Cells

Abstract Background: Investigating the factors that influence inflammatory response of microglial cells is important to understand the pathogenesis of cryptococcal meningitis (CM). MicroRNA (miRNA) have been shown to play an important role in inducing host defenses and activating immune response in the process of microbial infection; however, the regulatory mechanisms of miRNAs in cryptococcal meningitis are poorly defined. In our previous analysis, we assessed the miRNA profiles of BV2 cells following Cryptococcus neoformans (C. neoformans) infection. In this study, we characterized the expression of miR-4792 in CM patients to further our understanding of the host response to pathogen infections. Results: miR-4792 was downregulated in BV2 cells infected with C. neoformans while its target gene EGFR was upregulated. Infected cells with up-regulated miR-4792 exhibited a trend towards decreased EGFR transcript expression, reduced MAPK signaling and a decreased secretion of inflammatory cytokines. Afterantifungal treatment in cryptococcal meningitis patients, the levels of miR-4792 in the CSF significantly increased, while the expression of EGFR significantly decreased. Conclusion: This study identified that miR-4792 and its target gene EGFR regulate the secretion of inflammatory cytokines in BV2 cells infected with C. neoformans. This furthers our knowledge of the inflammatoryresponses to fungal infections in the CNS.

scholarly journals MiR-4792 regulates inflammatory responses in Cryptococcus neoformans infected microglia

2020 ◽  
Author(s):  
Jianghan Chen ◽  
Guotai Yao ◽  
Xiaoli Wang ◽  
Qing Hou ◽  
Rui Gao ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Inflammatory Cytokines ◽  
Cryptococcal Meningitis ◽  
Inflammatory Responses ◽  
Fungal Infections ◽  
Mapk Signaling ◽  
Microbial Infection ◽  
Host Immune Responses ◽  
Egfr Expression ◽  
Bv2 Cells

Abstract Background: Investigating the factors that influence inflammatory response of microglial cells is important to understand the pathogenesis of cryptococcal meningitis (CM). MicroRNA (miRNA) have been shown to play an important role in inducing host defenses and activating immune response in the process of microbial infection; however, the regulatory mechanisms of miRNAs in cryptococcal meningitis are poorly defined. In our previous analysis, we assessed the miRNA profiles of BV2 cells following Cryptococcus neoformans (C. neoformans) infection. In this study, we characterized the expression of miR-4792 in CM patients to further our understanding of the host response to pathogen infections.Results: miR-4792 was downregulated in BV2 cells infected with C. neoformans while its target gene EGFR was upregulated. Infected cells with up-regulated miR-4792 exhibited decreased EGFR expression, reduced MAPK signaling and a decreased secretion of inflammatory cytokines. Following antifungal treatment in cryptococcal meningitis patients, the levels of miR-4792 in the CSF significantly increased, while the expression of EGFR significantly decreased.Conclusion: This study identified that miR-4792 and its target EGFR regulate the secretion of inflammatory cytokines in C. neoformans infected BV2 cells. This furthers our knowledge of the host immune responses to fungal infections in the CNS.

scholarly journals Protective Effect of Resveratrol Improves Systemic Inflammation Responses in LPS-Injected Lambs

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 872 ◽  
Author(s):  
Yanping Liang ◽  
Jianwei Zhou ◽  
Kaixi Ji ◽  
Hu Liu ◽  
Allan Degen ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Inflammatory Responses ◽  
Clinical Symptoms ◽  
Average Daily Gain ◽  
Clinical Signs ◽  
Blood Parameters ◽  
Mapk Signaling ◽  
Inflammatory Genes ◽  
Expression Levels ◽  
Daily Gain

Highly intensive livestock production often causes immune stress to animals, which makes them more susceptible to infections. The aim of this study was to examine whether resveratrol (Res) alleviates inflammation in lambs. In Experiment 1, 16 male lambs were injected with lipopolysaccharides (LPS) at an initial dose of 0.25, 1.25, and 2.5 μg/kg body weight (BW) for 9 days. Average daily gain and blood parameters were measured and clinical symptoms were recorded. In Experiment 2, 20 male lambs were injected intravenously with LPS (0 mg/kg) + Res (0 mg), LPS (2.5 μg /kg) + Res (0 mg, 82.5 mg, 165 mg, 330 mg), 4 h after LPS injection. Jugular blood was collected from each lamb to determine white blood cell (WBC) counts and the expression of inflammatory genes. In Experiment 1, all LPS-treated lambs showed clinical signs of sickness including rhinorrhea, lethargy, and shivering, and systemic inflammatory responses of increased inflammatory genes levels and cortisol concentration. The lambs had increased respiratory and heart rates and rectal temperature and decreased average daily gain and feed intake. In Experiment 2, resveratrol significantly reduced WBCs and the expression levels of several genes associated with inflammation response (TLR4, NF-κB, c-jun) and inhibited the signaling cascades of NF-κB and MAPKs by down-regulating the expression levels of inflammatory cytokines (IL-1β, IL-4, IL-6, TNF-α, IFN-γ) induced by LPS. Resveratrol attenuated the LPS-evoked inflammatory responses in lambs by suppressing expression levels of inflammatory cytokines, and blocking NF-κB and MAPK signaling pathways.

scholarly journals An Antivirulence Approach for Preventing Cryptococcus neoformans from Crossing the Blood-Brain Barrier via Novel Natural Product Inhibitors of a Fungal Metalloprotease

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Phylicia A. Aaron ◽  
Kiem Vu ◽  
Angie Gelli
Keyword(s):  
Cryptococcus Neoformans ◽  
Blood Brain Barrier ◽  
Cryptococcal Meningitis ◽  
Mammalian Cells ◽  
Large Scale ◽  
Fungal Infections ◽  
Antifungal Drugs ◽  
Brain Barrier ◽  
Content Type ◽  
Blood Brain

ABSTRACT Cryptococcus neoformans (Cn) is the leading cause of fungal meningitis, a deadly disease with limited therapeutic options. Dissemination to the central nervous system hinges on the ability of Cn to breach the blood-brain barrier (BBB) and is considered an attribute of Cn virulence. Targeting virulence instead of growth for antifungal drug development has not been fully exploited despite the benefits of this approach. Mpr1 is a secreted fungal metalloprotease not required for fungal growth, but rather, it functions as a virulence factor by facilitating Cn migration across the BBB. This central role for Mpr1, its extracellular location, and lack of expression in mammalian cells make Mpr1 a high-value target for an antivirulence approach aimed at developing therapeutics for cryptococcal meningitis. To test this notion, we devised a large-scale screen to identify compounds that prohibited Cn from crossing the BBB by selectively blocking Mpr1 proteolytic activity, without inhibiting the growth of Cn. A phytochemical natural product-derived library was screened to identify new molecular scaffolds of prototypes unique to a Cn microecosystem. Of the 240 pure natural products examined, 3 lead compounds, abietic acid, diosgenin, and lupinine inhibited Mpr1 proteolytic activity with 50% inhibitory concentration (IC50) values of <10 μM, displayed little to no mammalian cell toxicity, and did not affect Cn growth. Notably, the lead compounds blocked Cn from crossing the BBB, without damaging the barrier integrity, suggesting the bioactive molecules had no off-target effects. We propose that these new drug scaffolds are promising candidates for the development of antivirulence therapy against cryptococcal meningitis. IMPORTANCE Fungal infections like cryptococcal meningitis are difficult to resolve because of the limited therapies available. The small arsenal of antifungal drugs reflect the difficulty in finding available targets in fungi because like mammalian cells, fungi are eukaryotes. The limited efficacy, toxicity, and rising resistance of antifungals contribute to the high morbidity and mortality of fungal infections and further underscore the dire but unmet need for new antifungal drugs. The traditional approach in antifungal drug development has been to target fungal growth, but an attractive alternative is to target mechanisms of pathogenesis. An important attribute of Cryptococcus neoformans (Cn) pathogenesis is its ability to enter the central nervous system. Here, we describe a large-scale screen that identified three natural products that prevented Cn from crossing the blood-brain barrier by inhibiting the virulence factor Mpr1 without affecting the growth of Cn. We propose that compounds identified here could be further developed as antivirulence therapy that would be administered preemptively or serve as a prophylactic in patients at high risk for developing cryptococcal meningitis.

scholarly journals MiR-200c-3p inhibits LPS-induced M1 polarization of BV2 cells by targeting RIP2

2022 ◽  
Author(s):  
Lei Zhao ◽  
Xiaosong Liu ◽  
Jiankai Yang ◽  
Xiaoliang Wang ◽  
Xiaomeng Liu ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
M1 Polarization ◽  
Bv2 Cells ◽  
M1 Phenotype ◽  
Lps Treatment ◽  
Pro Inflammatory Cytokines

Abstract Background Microglia are important immune cells, which can be induced by lipopolysaccharide (LPS) into M1 phenotype that express pro-inflammatory cytokines. Some studies have shown that microRNAs play critical roles in microglial activation. Objective This study was designed to investigate the role of miR-200c-3p in regulating inflammatory responses of LPS-treated BV2 cells. Methods The expression of miR-200c-3p in BV2 cells was detected by real-time PCR. Receptor-interacting protein 2 (RIP2) was predicted as a target gene of miR-200c-3p. Their relationship was verified by dual-luciferase reporter assay. The function of miR-200c-3p and RIP2 in microglial polarization and NF-κB signaling was further evaluated. Results LPS treatment reduced miR-200c-3p expression in a dose-dependent and time-dependent manner in BV2 cells. LPS treatment increased the expression of M1 phenotype markers inducible nitric oxide synthase (iNOS) and major histocompatibility complex class (MHC)-II, promoted the release of pro-inflammatory cytokines interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, and enhanced the nuclear translocation and phosphorylation of nuclear factor-kappaB (NF-κB) p65. Reversely, miR-200c-3p mimics down-regulated the levels of these inflammatory factors. Furthermore, RIP2 was identified to be a direct target of miR-200c-3p. RIP2 knockdown had a similar effect to miR-200c-3p mimics. Overexpression of RIP2 eliminated the inhibitory effect of miR-200c-3p on LPS-induced M1 polarization and NF-κB activation in BV2 cells. Conclusions MiR-200c-3p mimics suppressed LPS-induced microglial M1 polarization and NF-κB activation by targeting RIP2. MiR-200c-3p/RIP2 might be a potential therapeutic target for the treatment of neuroinflammation-associated diseases.

scholarly journals Designing of RNA Molecule Translating for Activitable Melittin as Selective Targeting of Leishmania Infected Cells

2021 ◽  
Author(s):  
Soheila Akhzari ◽  
Sedigheh Nabian ◽  
Parviz Shayan ◽  
Ramin Mazaheri Nezhad Fard ◽  
Minoo Soltani ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Matrix Metalloproteinase ◽  
Inflammatory Cytokines ◽  
Inflammatory Responses ◽  
Inhibitory Effects ◽  
Complementary Sequences ◽  
Selective Targeting ◽  
Selective Expression ◽  
Infected Cells ◽  
Induction Of Apoptosis

Background: Leishmaniasis is characterized by strong inflammatory responses with high levels of inflammatory cytokines that induce microRNA 21 and matrix metalloproteinases. Melittin has inhibitory effects on proliferation of various cells via induction of apoptosis. Melittin can be integrated in cell membranes and induce apoptosis. Thus, designation of biomolecules for the selective destroy of the infected cells is a treatment option. One approach is the precise engineering of constructs for the selective expression of melittin in the infected cells. Methods: For this aim we designed a construct composing melittin nucleotide sequence and nucleotide sequence coding for polyanionic peptide function inhibitory element to further guarantee the selective function of melittin in inflamed tissues and infected cells, were included in a construct as melittin inhibitor via matrix metalloproteinase degradable linker. Results: Reverse complementary sequences were designed so melittin sequences for the selective targeting of Leishmania could be expressed in infected cells using cell microRNA machinery. Conclusion: Translation machinery in infected cells with increased miR-21 could translate melittin, MMP linker and polyanionic inhibitor through a non-canonical pathway. Then, the MMP linker is degraded and selective killing of Leishmania infected cells would happen.

scholarly journals Multilocus Sequence Typing Reveals A Unique Co-Dominant Population Structure of Cryptococcus Neoformans Var. Grubii in Vietnam

2017 ◽  
Author(s):  
Thanh Lam Tuan ◽  
Trieu Phan Hai ◽  
Sayaphet Rattanavong ◽  
Trinh Mai Nguyen ◽  
Anh Duong Van ◽  
...  
Keyword(s):  
Population Structure ◽  
Southeast Asia ◽  
East Asia ◽  
Cryptococcus Neoformans ◽  
Cryptococcal Meningitis ◽  
Multilocus Sequence Typing ◽  
Fungal Infections ◽  
Total N ◽  
Global Context ◽  
The Relationship

AbstractCryptococcosis is amongst the most important invasive fungal infections globally, with cryptococcal meningitis causing an estimated 180,000 deaths each year in HIV infected patients alone. Patients with other forms of immunosuppression are also at risk, and disease is increasingly recognized in apparently immunocompetent individuals. Cryptococcus neoformans var. grubii (serotype A, molecular type VNI) has a global distribution and is responsible for the majority of cases. Here, we used the consensus ISHAM Multilocus Sequence Typing (MLST) for C. neoformans to define the population structure of clinical isolates of Cryptococcus neoformans var. grubii from Vietnam (n=136) and Laos (n=81). We placed these isolates into the global context using published MLST data from 8 other countries (total N = 669). We observed a phylo-geographical relationship in which Laos was similar to its Southeast Asian neighbor Thailand in being dominated (83%) by Sequence Type (ST) 4 and its Single Locus Variant ST6. On the other hand, Vietnam was uniquely intermediate between Southeast Asia and East Asia having both ST4/ST6 (35%) and ST5 (48%) which causes the majority of cases in East Asia. Analysis of genetic distance (Fst) between different populations of Cryptococcus neoformans var. grubii supported the intermediate nature of the population from Vietnam. A strong association between ST5 and infection in apparently immunocompetent, HIV-uninfected patients was observed in Vietnam (OR: 7.97, [95%CI: 3.18-19.97], p < 0.0001). Our study emphasizes that Vietnam, with its intermediate Cryptococcus neoformans var. grubii population structure, provides the strongest epidemiological evidence of the relationship between ST5 and infection of HIV-uninfected patients. Human population genetic distances within the region suggest these differences in CNVG population across Southeast Asia are driven by ecological factors rather than host factors.Author summaryCryptococcus neoformans is a yeast that causes meningitis in people, usually with damaged immune systems. There are >180,000 deaths in HIV-infected patients each year, most occurring where there are the highest HIV/AIDS disease burdens. Vietnam and Laos have contributed significantly to clinical trials aiming to improve the treatment of cryptococcal meningitis, but the relationship of isolates from these countries to the global population is not yet described. Here, we address this knowledge gap by using Multilocus Sequence Typing to study the population of Cryptococcus neoformans var. grubii (CNVG) in Laos and Vietnam, with the specific aim of incorporating these populations into the wider global context. We found that, in most countries, a single lineage (family) of strains was responsible for most disease. The Vietnamese CNVG population was unusual in that 2 main lineages circulated at the same time. The Vietnamese CNVG population occupies a middle ground between Thailand/Laos in the west and China in the east. The differences in population structure moving from West to East are probably due to ecological differences. Disease in HIV uninfected patients was almost always due to members of a single family of strains (ST5).

scholarly journals Critical role for integrin-β4 in the attenuation of murine acute lung injury by simvastatin

2012 ◽  
Vol 303 (4) ◽  
pp. L279-L285 ◽  
Author(s):  
Weiguo Chen ◽  
Saad Sammani ◽  
Sumegha Mitra ◽  
Shwu Fan Ma ◽  
Joe G. N. Garcia ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Inflammatory Cytokines ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Mapk Signaling ◽  
Blue Dye ◽  
Blocking Antibody ◽  
Cell Counts ◽  
Integrin Β4

The statins are a class of 3-hydroxy-3-methylglutaryl-coenzyme A-reductase inhibitors that are recognized to have pleiotropic properties. We previously reported the attenuation of LPS-induced murine acute lung injury (ALI) by simvastatin in vivo and identified relevant effects of simvastatin on endothelial cell (EC) signaling, activation, and barrier function in vitro. In particular, simvastatin induces the upregulation of integrin-β4, which in turn inhibits EC inflammatory responses via attenuation of MAPK signaling. The role of integrin-β4 in murine ALI protection by simvastatin, however, is unknown. We initially confirmed a time- and dose-dependent effect of simvastatin on increased integrin-β4 mRNA expression in human lung EC with peak protein expression evident at 16 h. Subsequently, reciprocal immunoprecipitation demonstrated an attenuation of LPS-induced integrin-β4 tyrosine phosphorylation by simvastatin (5 μM, 16 h). Increased expression of EC inflammatory cytokines [IL-6, IL-8, monocyte chemoattractant protein (MCP)-1, regulated on activation normal T cell expressed and secreted (RANTES)] by LPS (500 ng/ml, 4 h) was also significantly attenuated by simvastatin pretreatment (5 μM, 16 h), but this effect was reversed by cotreatment with an integrin-β4-blocking antibody. Finally, although simvastatin (20 mg/kg) conferred significant protection in murine ALI as evidenced by decreased bronchoalveolar lavage fluid cell counts, protein, inflammatory cytokines (IL-6, IL-1β, MCP-1, RANTES), decreased Evans blue dye albumin extravasation in lung tissue, and changes on lung histology, these effects were reversed by the integrin-β4-blocking antibody (IV, 1 mg/kg, 2 h before LPS). These findings support integrin-β4 as an important mediator of ALI protection by simvastatin and implicate signaling by integrin-β4 as a novel therapeutic target in patients with ALI.

scholarly journals Comparisons of the Anti-Inflammatory Activity of Dendropanax morbifera LEV Leaf Extract Contents Based on the Collection Season and Concentration of Ethanol as an Extraction Solvent

2020 ◽  
Vol 10 (23) ◽  
pp. 8756
Author(s):  
Kyeong Jin Kim ◽  
Ji Sun Youn ◽  
Young-Jun Kim ◽  
Ji Yeon Kim
Keyword(s):  
Inflammatory Cytokines ◽  
Inflammatory Responses ◽  
Ethanol Extract ◽  
Mapk Signaling ◽  
Hot Water ◽  
Mitogen Activated Protein Kinase ◽  
Inflammatory Activity ◽  
Dendropanax Morbifera ◽  
Anti Inflammatory ◽  
Ethanol Extracts

This study aimed to compare the anti-inflammatory activity of 10-year-old Dendropanax morbifera LEV (DM) leaf extracts. The leaves were collected during different seasons (May, August, and November), and the extracts were prepared using different methods (hot water, 30% ethanol, or 60% ethanol). Lipopolysaccharide-stimulated RAW264.7 cells were treated with these extracts for 12 h. The anti-inflammatory effects were evaluated by measuring the production of nitrite; prostaglandin E2 (PGE2); and inflammatory cytokines such as interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha, in addition to the mRNA expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 and activation of the nuclear factor κB (NF-κB)/mitogen-activated protein kinase (MAPK) pathways. The amyrin and polyphenol compositions of the extracts were analyzed using a triple time-of-flight mass spectrometer and high-performance liquid chromatography. The 30% ethanol extract harvested in May and 60% ethanol extracts collected in August and November displayed the highest inhibitions of nitrite, PGE2, and inflammatory cytokines. The 60% ethanol extract harvested in August suppressed activation of the NF-κB and MAPK signaling pathways. The contents of amyrin and polyphenol compounds were highly dependent on the ethanol concentration used during each season. These results suggest that ethanol extracts of DM leaves may have the potential to regulate inflammatory responses.

scholarly journals Oleanolic Acid Acetate Exerts Anti-Inflammatory Activity via IKKα/β Suppression in TLR3-Mediated NF-κB Activation

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 4002 ◽  
Author(s):  
Hyung Jin Lim ◽  
Hyun-Jae Jang ◽  
Mi Hwa Kim ◽  
Soyoung Lee ◽  
Seung Woong Lee ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Oleanolic Acid ◽  
Inflammatory Cytokines ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Anti Inflammatory ◽  
Tlr3 Signaling

Oleanolic acid acetate (OAA), a major triterpenoid compound of Vigna angularis (azuki bean, V. angularis), has been shown to downregulate inflammatory responses in macrophages. Here, we show the molecular basis for the effect of OAA on Toll-like receptor (TLR) downstream signaling. OAA treatment significantly inhibited the secretion of embryonic alkaline phosphatase (SEAP) induced by polyinosinic acid (poly(I), TLR3 ligand) in a dose-dependent manner and without cytotoxicity in THP1-XBlue cells. In addition, OAA downregulated the gene expression of poly(I) induced pro-inflammatory cytokines and chemokines genes such as MCP-1, IL-1β, IL-8, VCAM-1 and ICAM-1. Furthermore, we found that the inhibition activity of OAA was accompanied by decreased activation of not only nuclear factor-kappa B (NF-κB) signaling but also mitogen-activated protein kinase (MAPK) signaling upon stimulation with the TLR3 agonist. Interestingly, the interaction of OAA with IκB kinase α/β (IKKα/β) strongly attenuated the production of certain proteins and inflammatory cytokines in the TLR3 signaling pathway, such as nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IkBα), extracellular regulated kinases (ERK), and p38, in an in vitro model. The action of OAA was regulated by TLR3, demonstrating that TLR3 plays a critical role in mediating the physiologically-relevant anti-inflammatory action of OAA and that the interaction with IKKα/β is modulated through TLR3. These results reveal new insight into the understanding of the regulatory mechanisms of the downstream TLR3 signaling pathway and consequent inflammatory responses that are involved in the development and progression of inflammatory diseases.

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