More Like this

1. CD36‐Binding Amphiphilic Nanoparticles for Attenuation of α‐Synuclein‐Induced Microglial Activation

   https://doi.org/10.1002/anbr.202100120  

   Zhao, Nanxia ; Francis, Nicola L. ; Song, Shuang ; Kholodovych, Vladyslav ; Calvelli, Hannah R. ; Hoop, Cody L. ; Pang, Zhiping P. ; Baum, Jean ; Uhrich, Kathryn E. ; Moghe, Prabhas V. ( March 2022 , Advanced NanoBiomed Research)

   Neuroinflammation is one of the hallmarks contributing to Parkinson's disease (PD) pathology, where microglial activation occurs as one of the earliest events, triggered by extracellular α‐synuclein (aSYN) binding to the cluster of differentation 36 (CD36) receptor. Herein, CD36‐binding nanoparticles (NPs) containing tartaric acid–based amphiphilic macromolecules (AMs) are rationally designed to inhibit this aSYN–CD36 binding. In silico docking reveals that four AMs with varying alkyl side chain lengths present differential levels of CD36 binding affinity and that an optimal alkyl chain length promotes the strongest inhibitory activity toward aSYN–CD36 interactions. In vitro competitive binding assays indicate that the inhibitory activity of AM‐based NPs plateaus at intermediate side chain lengths of 12 and 18 carbons, supporting the in silico docking predictions. These intermediate‐length AM NPs also has significantly stronger effects on reducing aSYN internalization and inhibiting proinflammatory molecules tumor necrosis factor α (TNF‐α) and nitric oxide from aSYN‐challenged microglia. All four NPs modulate the gene expression of aSYN‐challenged microglia, downregulating proinflammatory genes TNF, interleukin 6 (IL‐6), and IL‐1β, and upregulating anti‐inflammatory genes transforming growth factor β (TGF‐β) and Arg1 expression. Herein, overall, a novel polymeric nanotechnology platform is represented that can be used to modulate aSYN‐induced microglial activation.

    

   more » « less
2. Circadian clock protein Rev-erbα regulates neuroinflammation

   https://doi.org/10.1073/pnas.1812405116  

   Griffin, Percy ; Dimitry, Julie M. ; Sheehan, Patrick W. ; Lananna, Brian V. ; Guo, Chun ; Robinette, Michelle L. ; Hayes, Matthew E. ; Cedeño, Michelle R. ; Nadarajah, Collin J. ; Ezerskiy, Lubov A. ; et al ( February 2019 , Proceedings of the National Academy of Sciences)

   Circadian dysfunction is a common attribute of many neurodegenerative diseases, most of which are associated with neuroinflammation. Circadian rhythm dysfunction has been associated with inflammation in the periphery, but the role of the core clock in neuroinflammation remains poorly understood. Here we demonstrate that Rev-erbα, a nuclear receptor and circadian clock component, is a mediator of microglial activation and neuroinflammation. We observed time-of-day oscillation in microglial immunoreactivity in the hippocampus, which was disrupted in Rev-erbα^−/−mice. Rev-erbα deletion caused spontaneous microglial activation in the hippocampus and increased expression of proinflammatory transcripts, as well as secondary astrogliosis. Transcriptomic analysis of hippocampus from Rev-erbα^−/−mice revealed a predominant inflammatory phenotype and suggested dysregulated NF-κB signaling. Primary Rev-erbα^−/−microglia exhibited proinflammatory phenotypes and increased basal NF-κB activation. Chromatin immunoprecipitation revealed that Rev-erbα physically interacts with the promoter regions of several NF-κB–related genes in primary microglia. Loss of Rev-erbα in primary astrocytes had no effect on basal activation but did potentiate the inflammatory response to lipopolysaccharide (LPS). In vivo, Rev-erbα^−/−mice exhibited enhanced hippocampal neuroinflammatory responses to peripheral LPS injection, while pharmacologic activation of Rev-erbs with the small molecule agonist SR9009 suppressed LPS-induced hippocampal neuroinflammation. Rev-erbα deletion influenced neuronal health, as conditioned media from Rev-erbα–deficient primary glial cultures exacerbated oxidative damage in cultured neurons. Rev-erbα^−/−mice also exhibited significantly altered cortical resting-state functional connectivity, similar to that observed in neurodegenerative models. Our results reveal Rev-erbα as a pharmacologically accessible link between the circadian clock and neuroinflammation.

    

   more » « less
3. Inflammasome Assays In Vitro and in Mouse Models

   https://doi.org/10.1002/cpim.107  

   Guo, Haitao ; Ting, Jenny P. ‐Y. ( October 2020 , Current Protocols in Immunology)

   This article presents assays that allow induction and measurement of activation of different inflammasomes in mouse macrophages, human peripheral blood mononuclear cell (PBMC) cultures, and mouse peritonitis and endotoxic shock models. Basic Protocol 1 describes how to prime the inflammasome in mouse macrophages with different Toll‐like receptor agonists and TNF‐α; how to induce NLRP1, NLRP3, NLRC4, and AIM2 inflammasome activation by their corresponding stimuli; and how to measure inflammasome activation‐mediated maturation of interleukin (IL)‐1β and IL‐18 and pyroptosis. Since the well‐established agonists for NLRP1 are inconsistent between mice and humans, Basic Protocol 2 describes how to activate the NLRP1 inflammasome in human PBMCs. Basic Protocol 3 describes how to purify, crosslink, and detect the apoptosis‐associated speck‐like protein containing a CARD (ASC) pyroptosome. Formation of the ASC pyroptosome is a signature of inflammasome activation. A limitation of ASC pyroptosome detection is the requirement of a relatively large cell number. Alternate Protocol 1 is provided to stain ASC pyroptosomes using an anti‐ASC antibody and to measure ASC specks by fluorescence microscopy in a single cell. Intraperitoneal injection of lipopolysaccharides (LPS) and inflammasome agonists will induce peritonitis, which is seen as an elevation of IL‐1β and other proinflammatory cytokines and an infiltration of neutrophils and inflammatory monocytes. Basic Protocol 4 describes how to induce NLRP3 inflammasome activation and peritonitis by priming mice with LPS and subsequently challenging them with monosodium urate (MSU). The method for measuring cytokines in serum and through peritoneal lavage is also described. Finally, Alternate Protocol 2 describes how to induce noncanonical NLRP3 inflammasome activation by high‐dose LPS challenge in a sepsis model. © 2020 Wiley Periodicals LLC.

   Basic Protocol 1: Priming and activation of inflammasomes in mouse macrophages

   Basic Protocol 2: Activation of human NLRP1 inflammasome by DPP8/9 inhibitor talabostat

   Basic Protocol 3: Purification and detection of ASC pyroptosome

   Alternate Protocol 1: Detection of ASC speck by immunofluorescence staining

   Basic Protocol 4: Activation of canonical NLRP3 inflammasome in mice by intraperitoneal delivery of MSU crystals

   Alternate Protocol 2: Activation of noncanonical NLRP3 inflammasome in mice by intraperitoneal delivery of LPS

    

   more » « less
4. Lactobacillus rhamnosus GG modifies the metabolome of pathobionts in gnotobiotic mice

   https://doi.org/10.1186/s12866-021-02178-2  

   Kim, Jinhee ; Balasubramanian, Iyshwarya ; Bandyopadhyay, Sheila ; Nadler, Ian ; Singh, Rajbir ; Harlan, Danielle ; Bumber, Amanda ; He, Yuling ; Kerkhof, Lee J. ; Gao, Nan ; et al ( December 2021 , BMC Microbiology)

   Abstract Background Lactobacillus rhamnosus GG (LGG) is the most widely used probiotic, but the mechanisms underlying its beneficial effects remain unresolved. Previous studies typically inoculated LGG in hosts with established gut microbiota, limiting the understanding of specific impacts of LGG on host due to numerous interactions among LGG, commensal microbes, and the host. There has been a scarcity of studies that used gnotobiotic animals to elucidate LGG-host interaction, in particular for gaining specific insights about how it modifies the metabolome. To evaluate whether LGG affects the metabolite output of pathobionts, we inoculated with LGG gnotobiotic mice containing Propionibacterium acnes, Turicibacter sanguinis, and Staphylococcus aureus (PTS). Results 16S rRNA sequencing of fecal samples by Ion Torrent and MinION platforms showed colonization of germ-free mice by PTS or by PTS plus LGG (LTS). Although the body weights and feeding rates of mice remained similar between PTS and LTS groups, co-associating LGG with PTS led to a pronounced reduction in abundance of P. acnes in the gut. Addition of LGG or its secretome inhibited P. acnes growth in culture. After optimizing procedures for fecal metabolite extraction and metabolomic liquid chromatography-mass spectrometry analysis, unsupervised and supervised multivariate analyses revealed a distinct separation among fecal metabolites of PTS, LTS, and germ-free groups. Variables-important-in-projection scores showed that LGG colonization robustly diminished guanine, ornitihine, and sorbitol while significantly elevating acetylated amino acids, ribitol, indolelactic acid, and histamine. In addition, carnitine, betaine, and glutamate increased while thymidine, quinic acid and biotin were reduced in both PTS and LTS groups. Furthermore, LGG association reduced intestinal mucosal expression levels of inflammatory cytokines, such as IL-1α, IL-1β and TNF-α. Conclusions LGG co-association had a negative impact on colonization of P. acnes , and markedly altered the metabolic output and inflammatory response elicited by pathobionts. 

   more » « less
5. Baseline mucus cytokines predict 22‐item Sino‐Nasal Outcome Test results after endoscopic sinus surgery

   https://doi.org/10.1002/alr.22449  

   Chowdhury, Naweed I. ; Li, Ping ; Chandra, Rakesh K. ; Turner, Justin H. ( October 2019 , International Forum of Allergy & Rhinology)

   Mucus cytokines have been linked to baseline metrics of quality of life and olfactory function in patients with chronic rhinosinusitis (CRS). However, their potential utility in predicting postoperative outcomes has not been assessed. Therefore, in this study we evaluated the role of mucus cytokines in predicting 22‐item Sino‐Nasal Outcomes Test (SNOT‐22) scores after endoscopic sinus surgery (ESS) in a prospective cohort of CRS patients.

   One hundred forty‐seven patients with CRS electing surgical therapy were enrolled in a longitudinal cohort study. Mucus was collected intraoperatively from the middle meatus and tested for interleukin (IL)‐1β, IL‐2, ‐4, ‐5, ‐6, ‐7,‐ 8, ‐9, ‐10, ‐12, ‐13, ‐17A, and ‐21; tumor necrosis factor (TNF)‐α; interferon‐γ; eotaxin; and RANTES (regulated‐on‐activation, normal T‐cell expressed and secreted) expression using a multiplex flow‐cytometric bead assay. Sixty‐two patients were followed postoperatively (average, 10.2 months) with baseline and follow‐up SNOT‐22 surveys. Stepwise multivariate linear regression was used to model relationships between baseline cytokines, phenotype, and average postoperative SNOT‐22 total and domain scores. A machine learning approach using a random forest algorithm was also used to investigate potential nonlinear relationships.

   IL‐5 was an independent predictor of postoperative total SNOT‐22 improvement (β = −8.8,p< 0.0001), whereas IL‐2 levels predicted postoperative worsening (β = 6.97,p= 0.0015). Similar relationships were also seen for postoperative SNOT‐22 domain scores. The overall model was also noted to be significant fit for the data (adjustedR²= 0.398,p< 0.0001). The random forest model similarly identified IL‐5, TNF‐α, IL‐13, and IL‐2 as major predictors of postoperative SNOT‐22 scores.

   Mucus cytokine profiles may help identify CRS patients who are likely to obtain postoperative improvement after ESS.

    

   more » « less