Abstract 190: Mesenchymal Stromal Cells (MSCs) Regulate Neutrophil Extracellular Traps (NETs) Through Adenosine

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Rebecca Levit ◽  
Eric Shin ◽  
LanFang Wang ◽  
Kai Xu
Keyword(s):  
Fold Increase ◽  
Innate Immune ◽  
Dependent Manner ◽  
Extracellular Traps ◽  
Sytox Green ◽  
Healthy Donors ◽  
A Cell ◽  
Anti Inflammatory ◽  
Dose Dependent

Background: NETs released by neutrophils may be an important component of inflammation in MI/R. NETs consist of extruded DNA, histone, and other chromatin components and are pro-thrombotic and pro-inflammatory. MSCs as a cell therapy for MI/R may act by modulating the innate immune response including NETs. MSCs convert pro-inflammatory ATP into anti-inflammatory adenosine (ADO) via CD 73, a 5’ ectonucleotidase. Objective: To investigate the role of MSCs in regulating NETs through ADO production. Methods: Neutrophils were freshly isolated from peripheral blood of healthy donors. Human bone marrow derived MSCs were grown under standard conditions. Neutrophils were stimulated to produce NETs by PMA (1 μg/ml) and quantified by Sytox green fluorescence. Some neutrophils were also treated with MSCs or ADO. Results: Neutrophils treated with PMA had a 1.9±0.19, (p<0.05) fold increase in NET formation as quantified by Sytox green florescence. Treatment with MSCs in 1:10 ratio prevented increased NET production in response to PMA (1.02±0.12 fold increase). Pretreatment of MSCs with a CD 73 inhibitor APCP reduced their ability to prevent NET formation in some donors (1.62±0.10). ADO decreased NET formation in a dose dependent manner. Conclusion: MSCs may inhibit NET formation through ADO signaling and could be an important mechanism of MSC anti-inflammatory effects in MI/R. Future studies will investigate the ability of MSCs to inhibit NET formation in MI/R.

Neutrophils in cardiovascular disease: warmongers, peacemakers, or both?

2021 ◽  
Author(s):  
Gopalkrishna Sreejit ◽  
Jillian Johnson ◽  
Robert M Jaggers ◽  
Albert Dahdah ◽  
Andrew J Murphy ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Innate Immune ◽  
Sterile Inflammation ◽  
Immune Memory ◽  
Dependent Manner ◽  
Cell Type ◽  
Complex Behaviour ◽  
One Dimensional ◽  
A Cell

Abstract Neutrophils, the most abundant of all leucocytes and the first cells to arrive at the sites of sterile inflammation/injury act as a double-edged sword. On one hand, they inflict a significant collateral damage to the tissues and on the other hand, they help facilitate wound healing by a number of mechanisms. Recent studies have drastically changed the perception of neutrophils from being simple one-dimensional cells with an unrestrained mode of action to a cell type that display maturity and complex behaviour. It is now recognized that neutrophils are transcriptionally active and respond to plethora of signals by deploying a wide variety of cargo to influence the activity of other cells in the vicinity. Neutrophils can regulate macrophage behaviour, display innate immune memory, and play a major role in the resolution of inflammation in a context-dependent manner. In this review, we provide an update on the factors that regulate neutrophil production and the emerging dichotomous role of neutrophils in the context of cardiovascular diseases, particularly in atherosclerosis and the ensuing complications, myocardial infarction, and heart failure. Deciphering the complex behaviour of neutrophils during inflammation and resolution may provide novel insights and in turn facilitate the development of potential therapeutic strategies to manage cardiovascular disease.

CCR1 Inhibition Impairs Osteoclast Activity and Interaction with Myeloma Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3494-3494
Author(s):  
Sonia Vallet ◽  
Noopur Raje ◽  
Kenji Ishitsuka ◽  
Teru Hideshima ◽  
Klaus Podar ◽  
...  
Keyword(s):  
Cell Migration ◽  
Fold Increase ◽  
Pit Formation ◽  
Inflammatory Protein ◽  
Healthy Donors ◽  
Direct Cytotoxicity ◽  
Dose Dependent Fashion ◽  
Dose Dependent ◽  
Modest Effect

Abstract Multiple Myeloma (MM) is characterized by increased osteoclasts (OC) activity leading to severe bone disease. Several inducers of OC number and activity have been identified, including several key chemokines. In particular, macrophage inflammatory protein-1α (MIP-1α) and RANTES activate CCR1 and CCR5, resulting in increased osteoclastogenesis (Oba et al. Exp Hematol. 2005) and increased OC motility (Yu X. J Bone Miner Res. 2004) These studies underscore the role of CCR1 in promoting osteoclastogenesis. Here we demonstrate the effects of inhibition of CCR1 with a specific receptor antagonist (MLN3897, Millenium Pharmaceuticals) on normal mature OC. Mature OC were obtained by stimulating PBMC of healthy donors with RANKL and MCSF (50 ng/ml) for three weeks. OC expressed high levels of CCR1 and secreted both MIP-1α (1 ng/ml +/− 1.8) and RANTES (12 pg/ml +/− 0.66), suggesting an autocrine effect of these chemokines. Analyzing the bone resorptive ability with a pit formation assay, we observed that MLN3897 impaired OC function in a dose-dependent fashion (at 10 nM: 20% of reduction in resorbed area, at 100 nM: 50% of reduction). We then studied the effects of CCR1 inhibition on OC viability by analyzing nuclear integrity with Hoechst33258 staining. After 12 hours of cytokine-deprivation, MLN3897 enhanced OC nuclear fragmentation and condensation, suggesting a role for CCR1 ligands in OC survival. We next studied the interactions between OC and MM cells. Because OC secrete several chemoattractants, we studied their ability to stimulate RPMI8226 MM cell migration. We first confirmed high expression levels of CCR1 on RPMI8226 MM cells by flow cytometry (86% compared to isotype control). Inhibition of CCR1 with MLN3897 did not induce any direct cytotoxicity or growth arrest of these cells. We then studied the effects of OC on RPMI8226 MM cells. We observed that OC potently stimulated migration of RPMI8226 MM cells (8-fold increase), which was almost completely blocked by treatment with MLN3897. In contrast, MIP-1α alone induced only a modest effect on migration: the highest effective concentration (0.5 ng/ml) induced only a 2-fold increase. Neutralizing MIP-1α antibody partially reversed these effects, suggesting that other factors may contribute to this migratory effect. Our data therefore demonstrate that CCR1 inhibition by MLN3897 impairs mature OC survival and activity. Although MLN3897 does not have any direct antiMM activity, it affects MM-OC interactions and inhibits MM cell migration to OC. Ongoing studies are further characterizing the effects of CCR1 inhibition on MM-OC interactions in order to provide the framework for its clinical evaluation in MM.

scholarly journals MicroRNA-106a Inhibits Autophagy Process and Antimicrobial Responses by Targeting ULK1, ATG7, and ATG16L1 During Mycobacterial Infection

2021 ◽  
Vol 11 ◽  
Author(s):  
Kunmei Liu ◽  
Dantong Hong ◽  
Fan Zhang ◽  
Xin Li ◽  
Meng He ◽  
...  
Keyword(s):  
Immune Response ◽  
Electron Microscope ◽  
Mycobacterial Infection ◽  
Inhibitory Effect ◽  
Innate Immune ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Transmission Electron ◽  
Dose Dependent

Autophagy is a key element of innate immune response against invading pathogens including Mycobacterium tuberculosis (M. tuberculosis). The emerging roles of microRNAs in regulating host antimicrobial responses against M. tuberculosis have gained widespread attention. However, the process by which miRNAs specifically influence antibacterial autophagy during mycobacterial infection is largely uncharacterized. In this study, we demonstrate a novel role of miR-106a in regulating macrophage autophagy against M. tuberculosis. H37Ra infection leads to downregulation of miR-106a in a time- and dose-dependent manner and concomitant upregulation of its three targets (ULK1, ATG7, and ATG16L1) in THP-1 macrophages. MiR-106a could inhibit autophagy activation and antimicrobial responses to M. tuberculosis by targeting ULK1, ATG7, and ATG16L1. Overexpression of miR-106a dramatically inhibited H37Ra-induced activation of autophagy in human THP-1 macrophages, whereas inhibitors of miR-106a remarkably promoted H37Ra-induced autophagy. The inhibitory effect of miR-106a on autophagy process during mycobacterial infection was also confirmed by Transmission Electron Microscope (TEM) observation. More importantly, forced expression of miR-106a increased mycobacterial survival, while transfection with miR-106a inhibitors attenuated the survival of intracellular mycobacteria. Taken together, these data demonstrated that miR-106a functioned as a negative regulator in autophagy and antimicrobial effects by targeting ULK1, ATG7, and ATG16L1 during M. tuberculosis infection, which may provide a potential target for developing diagnostic reagents or antibacterials against tuberculosis.

Abstract P210: (Pro)Renin Receptor Regulates Potassium Homeostasis via Intrarenal Aldosterone

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Chuanming Xu ◽  
Aihua Lu ◽  
Hong Wang ◽  
Hui Fang ◽  
Li Zhou ◽  
...  
Keyword(s):  
Protein Expression ◽  
Potential Role ◽  
Fold Increase ◽  
Dependent Manner ◽  
Sd Rats ◽  
High K ◽  
Functional Implications ◽  
Calcium Activated Potassium Channel ◽  
Dose Dependent

It has been shown that transgenic overexpression of human (pro)renin receptor (PRR) results in elevated aldosterone (Aldo) level with unclear functional implications. The present study examined a potential role of renal PRR during high K + (HK) loading. In normal SD rats, a 1-week HK intake (5% KCl in diet) induced a 3.4-fold increase in renal protein expression of full-length PRR and 4.2-fold increase in urinary excretion of soluble PRR (sPRR). Administration of PRO20, a decoy peptide antagonist of PRR, at 700 μg/kg/d via i.p. injections, to K + -loaded animals elevated plasma K + level (5.72+0.08 vs. 4.84±0.18 mM, p<0.05) and decreased urinary K + excretion (2.52+0.11 vs. 3.43+0.19 mmol/24h, p<0.05), accompanied with a 26.2% reduction of urinary aldosterone (Aldo) excretion. HK downregulated NCC protein expression (57.8%) and upregulated renal protein expression of aldosterone synthase CYP11B2 (229%), ROMK (156%), calcium-activated potassium channel subunit alpha-1 (α-BK) (367%), α-Na + -K + -ATPase (596%), and β-ENaC (155%), all of which were significantly blunted by PRO20 (by 50 - 70%). The same maneuvers were applied to adrenalectomized (ADX) rats. Although plasma Aldo was extremely low and also unresponsive to HK loading, urinary Aldo excretion was elevated by 274% with this treatment, which was abolished by PRO20. The HK-induced responses of the above K + and Na + transporting proteins in ADX rats all persisted and also remained sensitive to PRO20. Additionally, spironolactone treatment in ADX rats was still effective in inhibiting kaliuresis induced by HK loading, resulting in hyperkalemia (Plasma K+: 5.13±0.07 vs. 4.19±0.27 mM, p<0.05). In primary rat IMCD cells, exposure to 10 mM KCl for 24 h augmented PRR protein expression and sPRR release in a time- and dose-dependent manner. HK upregulated Aldo release in parallel with increased CYP11B2 protein expression, which were both attenuated by PRO20 or PRR siRNA. A recombinant sPRR, sPRR-His, stimulated Aldo release and CYP11B2 expression. Taken together, we conclude that HK increased renal PRR expression that stimulates renal synthesis of Aldo that coordinates the response of renal membrane Na + and K + transporting proteins to facilitate K + secretion.

Amelioration of Carbon Tetrachloride-Induced Liver Injury by Citrus Leaf Extract

2019 ◽  
Vol 17 (4) ◽  
pp. 426-431
Author(s):  
Jin Xuezhu ◽  
Li Jitong ◽  
Nie Leigang ◽  
Xue Junlai
Keyword(s):  
Carbon Tetrachloride ◽  
Leaf Extract ◽  
Hepatic Injury ◽  
The Body ◽  
Dependent Manner ◽  
Weight Changes ◽  
Citrus Leaf ◽  
Dose Dependent ◽  
And Oxidative Stress

The main purpose of this study is to investigate the role of citrus leaf extract in carbon tetrachloride-induced hepatic injury and its potential molecular mechanism. Carbon tetrachloride was used to construct hepatic injury animal model. To this end, rats were randomly divided into 4 groups: control, carbon tetrachloride-treated, and two carbon tetrachloride + citrus leaf extract-treated groups. The results show that citrus leaf extract treatment significantly reversed the effects of carbon tetrachloride on the body weight changes and liver index. Besides, treatment with citrus leaf extract also reduced the levels of serum liver enzymes and oxidative stress in a dose-dependent manner. H&E staining and western blotting suggested that citrus leaf extract could repair liver histological damage by regulating AMPK and Nrf-2.

scholarly journals High-dose Glycerol Monolaurate Up-Regulated Beneficial Indigenous Microbiota without Inducing Metabolic Dysfunction and Systemic Inflammation: New Insights into Its Antimicrobial Potential

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1981 ◽  
Author(s):  
Qiufen Mo ◽  
Aikun Fu ◽  
Lingli Deng ◽  
Minjie Zhao ◽  
Yang Li ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Systemic Inflammation ◽  
Body Weight Gain ◽  
High Dose ◽  
Dependent Manner ◽  
Glucose And Lipid Metabolism ◽  
Glycerol Monolaurate ◽  
Indigenous Microbiota ◽  
Anti Inflammatory ◽  
Dose Dependent

Glycerol monolaurate (GML) has potent antimicrobial and anti-inflammatory activities. The present study aimed to assess the dose-dependent antimicrobial-effects of GML on the gut microbiota, glucose and lipid metabolism and inflammatory response in C57BL/6 mice. Mice were fed on diets supplemented with GML at dose of 400, 800 and 1600 mg kg−1 for 4 months, respectively. Results showed that supplementation of GML, regardless of the dosages, induced modest body weight gain without affecting epididymal/brown fat pad, lipid profiles and glycemic markers. A high dose of GML (1600 mg kg−1) showed positive impacts on the anti-inflammatory TGF-β1 and IL-22. GML modulated the indigenous microbiota in a dose-dependent manner. It was found that 400 and 800 mg kg−1 GML improved the richness of Barnesiella, whereas a high dosage of GML (1600 mg kg−1) significantly increased the relative abundances of Clostridium XIVa, Oscillibacter and Parasutterella. The present work indicated that GML could upregulate the favorable microbial taxa without inducing systemic inflammation and dysfunction of glucose and lipid metabolism.

scholarly journals The Role of the Pathogen Dose and PI3Kγ in Immunometabolic Reprogramming of Microglia for Innate Immune Memory

2021 ◽  
Vol 22 (5) ◽  
pp. 2578
Author(s):  
Trim Lajqi ◽  
Christian Marx ◽  
Hannes Hudalla ◽  
Fabienne Haas ◽  
Silke Große ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Immune Tolerance ◽  
Immune Cells ◽  
Low Dose ◽  
Innate Immune ◽  
Immune Memory ◽  
Innate Immune Cells ◽  
Atp Production ◽  
Dose Dependent

Microglia, the innate immune cells of the CNS, exhibit long-term response changes indicative of innate immune memory (IIM). Our previous studies revealed IIM patterns of microglia with opposing immune phenotypes: trained immunity after a low dose and immune tolerance after a high dose challenge with pathogen-associated molecular patterns (PAMP). Compelling evidence shows that innate immune cells adopt features of IIM via immunometabolic control. However, immunometabolic reprogramming involved in the regulation of IIM in microglia has not been fully addressed. Here, we evaluated the impact of dose-dependent microglial priming with ultra-low (ULP, 1 fg/mL) and high (HP, 100 ng/mL) lipopolysaccharide (LPS) doses on immunometabolic rewiring. Furthermore, we addressed the role of PI3Kγ on immunometabolic control using naïve primary microglia derived from newborn wild-type mice, PI3Kγ-deficient mice and mice carrying a targeted mutation causing loss of lipid kinase activity. We found that ULP-induced IIM triggered an enhancement of oxygen consumption and ATP production. In contrast, HP was followed by suppressed oxygen consumption and glycolytic activity indicative of immune tolerance. PI3Kγ inhibited glycolysis due to modulation of cAMP-dependent pathways. However, no impact of specific PI3Kγ signaling on immunometabolic rewiring due to dose-dependent LPS priming was detected. In conclusion, immunometabolic reprogramming of microglia is involved in IIM in a dose-dependent manner via the glycolytic pathway, oxygen consumption and ATP production: ULP (ultra-low-dose priming) increases it, while HP reduces it.

scholarly journals PapRIV, a BV-2 microglial cell activating quorum sensing peptide

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yorick Janssens ◽  
Nathan Debunne ◽  
Anton De Spiegeleer ◽  
Evelien Wynendaele ◽  
Marta Planas ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Cell Model ◽  
Dependent Manner ◽  
Communication Signals ◽  
Gram Positive Bacteria ◽  
A Cell ◽  
Gastro Intestinal Tract

AbstractQuorum sensing peptides (QSPs) are bacterial peptides produced by Gram-positive bacteria to communicate with their peers in a cell-density dependent manner. These peptides do not only act as interbacterial communication signals, but can also have effects on the host. Compelling evidence demonstrates the presence of a gut-brain axis and more specifically, the role of the gut microbiota in microglial functioning. The aim of this study is to investigate microglial activating properties of a selected QSP (PapRIV) which is produced by Bacillus cereus species. PapRIV showed in vitro activating properties of BV-2 microglia cells and was able to cross the in vitro Caco-2 cell model and reach the brain. In vivo peptide presence was also demonstrated in mouse plasma. The peptide caused induction of IL-6, TNFα and ROS expression and increased the fraction of ameboid BV-2 microglia cells in an NF-κB dependent manner. Different metabolites were identified in serum, of which the main metabolite still remained active. PapRIV is thus able to cross the gastro-intestinal tract and the blood–brain barrier and shows in vitro activating properties in BV-2 microglia cells, hereby indicating a potential role of this quorum sensing peptide in gut-brain interaction.

scholarly journals Lumican Inhibits Osteoclastogenesis and Bone Resorption by Suppressing Akt Activity

2021 ◽  
Vol 22 (9) ◽  
pp. 4717
Author(s):  
Jin-Young Lee ◽  
Da-Ae Kim ◽  
Eun-Young Kim ◽  
Eun-Ju Chang ◽  
So-Jeong Park ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Map Kinases ◽  
Osteoclast Differentiation ◽  
Dependent Manner ◽  
Dual Action ◽  
Dose Dependent ◽  
Resorptive Activity

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.

Role of extracellular calcium and calmodulin in prolactin secretion induced by hyposmolarity, thyrotropin-releasing hormone, and high K+ in GH4C1 cells

1990 ◽  
Vol 123 (2) ◽  
pp. 218-224 ◽  
Author(s):  
Xiangbing Wang ◽  
Noriyuki Sato ◽  
Monte A. Greer ◽  
Susan E. Greer ◽  
Staci McAdams
Keyword(s):  
Smooth Muscle ◽  
Muscle Relaxant ◽  
Prolactin Secretion ◽  
Thyrotropin Releasing Hormone ◽  
Dependent Manner ◽  
Cell Toxicity ◽  
High K ◽  
Dose Dependent ◽  
Smooth Muscle Relaxant

Abstract. The mechanism by which 30% medium hyposmolarity induces PRL secretion by GH4C1 cells was compared with that induced by 100 nmol/l TRH or 30 mmol/l K+. Removing medium Ca2+, blocking Ca2+ channels with 50 μmol/l verapamil, or inhibiting calmodulin activation with 20 μmol/l trifluoperazine, 10 μmol/l chlorpromazine or 10 μmol/l pimozide almost completely blocked hyposmolarity-induced secretion. The smooth muscle relaxant, W-7, which is believed relatively specific in inhibiting the Ca2+-calmodulin interaction, depressed hyposmolarity-induced PRL secretion in a dose-dependent manner (r = −0.991, p<0.01 ). The above drugs also blocked or decreased high K+-induced secretion, but had much less effect on TRH-induced secretion. Secretion induced by TRH, hyposmolarity, or high K+ was optimal at pH 7.3-7.65 and was significantly depressed at pH 6.0 or 8.0, indicating that release of hormone induced by all 3 stimuli is due to an active cell process requiring a physiologic extracellular pH and is not produced by nonspecific cell toxicity. The data suggest hyposmolarity and high K+ may share some similarities in their mechanism of stimulating secretion, which is different from that of TRH.

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