scholarly journals Activation of PKCε-ALDH2 Axis Prevents 4-HNE-Induced Pain in Mice

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1798
Author(s):  
Bárbara B. Martins ◽  
Natália G. Hösch ◽  
Queren A. Alcantara ◽  
Grant R. Budas ◽  
Che-Hong Chen ◽  
...  
Keyword(s):  
Small Molecules ◽  
Potential Treatment ◽  
Proof Of Concept ◽  
Aldehyde Dehydrogenase 2 ◽  
Nociceptive Behavior ◽  
Selective Activation ◽  
Mechanical Hypersensitivity ◽  
Inflammatory Conditions ◽  
Endogenous Production ◽  
Deficient Mice

Protein kinase Cε (PKCε) is highly expressed in nociceptor neurons and its activation has been reported as pro-nociceptive. Intriguingly, we previously demonstrated that activation of the mitochondrial PKCε substrate aldehyde dehydrogenase-2 (ALDH2) results in anti-nociceptive effects. ALDH2 is a major enzyme responsible for the clearance of 4-hydroxy-2-nonenal (4-HNE), an oxidative stress byproduct accumulated in inflammatory conditions and sufficient to induce pain hypersensitivity in rodents. Here we determined the contribution of the PKCε-ALDH2 axis during 4-HNE-induced mechanical hypersensitivity. Using knockout mice, we demonstrated that PKCε is essential for the nociception recovery during 4-HNE-induced hypersensitivity. We also found that ALDH2 deficient knockin mice display increased 4-HNE-induced nociceptive behavior. As proof of concept, the use of a selective peptide activator of PKCε (ΨεHSP90), which favors PKCε translocation to mitochondria and activation of PKCε-ALDH2 axis, was sufficient to block 4-HNE-induced hypersensitivity in WT, but not in ALDH2-deficient mice. Similarly, ΨεHSP90 administration prevented mechanical hypersensitivity induced by endogenous production of 4-HNE after carrageenan injection. These findings provide evidence that selective activation of mitochondrial PKCε-ALDH2 axis is important to mitigate aldehyde-mediated pain in rodents, suggesting that ΨεHSP90 and small molecules that mimic it may be a potential treatment for patients with pain.

scholarly journals Maintenance of Type 2 Response by CXCR6-Deficient ILC2 in Papain-Induced Lung Inflammation

2019 ◽  
Vol 20 (21) ◽  
pp. 5493 ◽  
Author(s):  
Meunier ◽  
Chea ◽  
Garrido ◽  
Perchet ◽  
Petit ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Nk Cell ◽  
Lymphoid Cells ◽  
Inflammatory Conditions ◽  
Airway Diseases ◽  
Type 2 Cytokines ◽  
Lymphoid Organogenesis ◽  
Deficient Mice

Innate lymphoid cells (ILC) are important players of early immune defenses in situations like lymphoid organogenesis or in case of immune response to inflammation, infection and cancer. Th1 and Th2 antagonism is crucial for the regulation of immune responses, however mechanisms are still unclear for ILC functions. ILC2 and NK cells were reported to be both involved in allergic airway diseases and were shown to be able to interplay in the regulation of the immune response. CXCR6 is a common chemokine receptor expressed by all ILC, and its deficiency affects ILC2 and ILC1/NK cell numbers and functions in lungs in both steady-state and inflammatory conditions. We determined that the absence of a specific ILC2 KLRG1+ST2– subset in CXCR6-deficient mice is probably dependent on CXCR6 for its recruitment to the lung under inflammation. We show that despite their decreased numbers, lung CXCR6-deficient ILC2 are even more activated cells producing large amount of type 2 cytokines that could drive eosinophilia. This is strongly associated to the decrease of the lung Th1 response in CXCR6-deficient mice.

scholarly journals Minimal mechanistic component of proteasome activation and prevention of impairment by pathological oligomers

2021 ◽  
Author(s):  
Janelle Chuah ◽  
Tifffany Thibaudeau ◽  
David Smith
Keyword(s):  
Small Molecules ◽  
Conformational Changes ◽  
Bound State ◽  
Proof Of Concept ◽  
Α Subunit ◽  
Gate Opening ◽  
Allosteric Mechanism ◽  
Dependent Mechanism ◽  
Degradation Of Peptides

Abstract Impairment of proteasomal function has been implicated in neurodegenerative diseases, justifying the need to understand how the proteasome is activated for protein degradation. Here, using biochemical and structural (cryo-EM) strategies in both archaeal and mammalian proteasomes, we further determine the HbYX(-motif)-dependent mechanism of proteasomal activation used by multiple proteasome-activating complexes including the 19S Particle. We identify multiple proteasome α subunit residues involved in HbYX-dependent activation, a point mutation that activates the proteasome by partially mimicking a HbYX-bound state, and conformational changes involved in gate-opening with a 2.0A structure. Through an iterative process of peptide synthesis, we successfully design a HbYX-like dipeptide mimetic as a robust tool to elucidate how the motif autonomously activates the proteasome. The mimetic induces near complete gate-opening at saturating concentration, activating mammalian proteasomal degradation of peptides and proteins. Findings using our peptide mimetic suggest the HbYX-dependent mechanism requires cooperative binding in at least two intersubunit pockets of the α ring. Collectively, the results presented here unambiguously demonstrate the lone role of the HbYX tyrosine in the allosteric mechanism of proteasome activation and offer proof of concept for the robust potential of HbYX-like small molecules to activate the proteasome.

scholarly journals Human miRNA miR-675 inhibits DUX4 expression and may be exploited as a potential treatment for Facioscapulohumeral muscular dystrophy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nizar Y. Saad ◽  
Mustafa Al-Kharsan ◽  
Sara E. Garwick-Coppens ◽  
Gholamhossein Amini Chermahini ◽  
Madison A. Harper ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Muscular Dystrophy ◽  
Small Molecules ◽  
Skeletal Muscles ◽  
Disease Gene ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Potential Treatment ◽  
Cell Models ◽  
Powerful Approach ◽  
Dominant Disease

AbstractFacioscapulohumeral muscular dystrophy (FSHD) is a potentially devastating myopathy caused by de-repression of the DUX4 gene in skeletal muscles. Effective therapies will likely involve DUX4 inhibition. RNA interference (RNAi) is one powerful approach to inhibit DUX4, and we previously described a RNAi gene therapy to achieve DUX4 silencing in FSHD cells and mice using engineered microRNAs. Here we report a strategy to direct RNAi against DUX4 using the natural microRNA miR-675, which is derived from the lncRNA H19. Human miR-675 inhibits DUX4 expression and associated outcomes in FSHD cell models. In addition, miR-675 delivery using gene therapy protects muscles from DUX4-associated death in mice. Finally, we show that three known miR-675-upregulating small molecules inhibit DUX4 and DUX4-activated FSHD biomarkers in FSHD patient-derived myotubes. To our knowledge, this is the first study demonstrating the use of small molecules to suppress a dominant disease gene using an RNAi mechanism.

scholarly journals Acid Sphingomyelinase Deficiency Ameliorates Farber Disease

2019 ◽  
Vol 20 (24) ◽  
pp. 6253 ◽  
Author(s):  
Nadine Beckmann ◽  
Katrin Anne Becker ◽  
Stephanie Kadow ◽  
Fabian Schumacher ◽  
Melanie Kramer ◽  
...  
Keyword(s):  
Therapeutic Target ◽  
Treatment Options ◽  
Acid Sphingomyelinase ◽  
Proof Of Concept ◽  
Lysosomal Storage ◽  
Acid Ceramidase ◽  
Farber Disease ◽  
Ceramidase Deficiency ◽  
Ceramide Accumulation ◽  
Deficient Mice

Farber disease is a rare lysosomal storage disorder resulting from acid ceramidase deficiency and subsequent ceramide accumulation. No treatments for Farber disease are clinically available, and affected patients have a severely shortened lifespan. We have recently reported a novel acid ceramidase deficiency model that mirrors the human disease closely. Acid sphingomyelinase is the enzyme that generates ceramide upstream of acid ceramidase in the lysosomes. Using our acid ceramidase deficiency model, we tested if acid sphingomyelinase could be a potential novel therapeutic target for the treatment of Farber disease. A number of functional acid sphingomyelinase inhibitors are clinically available and have been used for decades to treat major depression. Using these as a therapeutic for Farber disease, thus, has the potential to improve central nervous symptoms of the disease as well, something all other treatment options for Farber disease can’t achieve so far. As a proof-of-concept study, we first cross-bred acid ceramidase deficient mice with acid sphingomyelinase deficient mice in order to prevent ceramide accumulation. Double-deficient mice had reduced ceramide accumulation, fewer disease manifestations, and prolonged survival. We next targeted acid sphingomyelinase pharmacologically, to test if these findings would translate to a setting with clinical applicability. Surprisingly, the treatment of acid ceramidase deficient mice with the acid sphingomyelinase inhibitor amitriptyline was toxic to acid ceramidase deficient mice and killed them within a few days of treatment. In conclusion, our study provides the first proof-of-concept that acid sphingomyelinase could be a potential new therapeutic target for Farber disease to reduce disease manifestations and prolong survival. However, we also identified previously unknown toxicity of the functional acid sphingomyelinase inhibitor amitriptyline in the context of Farber disease, strongly cautioning against the use of this substance class for Farber disease patients.

Spinal disulfide HMGB1, but not all-thiol HMGB1, induces mechanical hypersensitivity in a TLR4-dependent manner

2015 ◽  
Vol 8 (1) ◽  
pp. 47-47 ◽  
Author(s):  
N.M. Agalave ◽  
S. AbdelMoaty ◽  
P. Lundback ◽  
U. Andersson ◽  
H. Harris ◽  
...  
Keyword(s):  
Intrathecal Injection ◽  
Animal Experiments ◽  
High Mobility ◽  
Disulfide Bridge ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Mechanical Hypersensitivity ◽  
Thiol Form ◽  
Lumbar Spinal ◽  
Deficient Mice

Abstract Aims Increasing evidence indicates that extracellular high mobility group box-1 protein (HMGB1) is involved in the pathogenesis of inflammatory and autoimmune disease. Data from our laboratory demonstrates that HMGB1 contributes to nociceptive behavior in a model of rheumatoid arthritis-induced pain. HMGB1 binds to multiple receptors, including toll like receptor (TLR) 2, TLR4 and receptor for advanced glycation end products (RAGE). When the cysteine in position C106 is in the reduced thiol form and C23 and C45 are engaged in a disulfide bridge (disulfide HMGB1), the molecule functions as a cytokine-inducing TLR4 ligand. In contrast, when these three cysteines are all reduced (all-thiol HMGB1), HMGB1 exclusively potentiates chemotactic activity via CXCR4. It is currently not well understood which receptor and which redox form of HMGB1 that mediates pain hypersensitivity and is therefore the aim of this study. Methods All animal work was carried out in accordance with protocol approved by the local ethics committee for animal experiments in Sweden. Balb/c, C57B/l6 (WT), Tlr2–/–, Tlr4–/– and Rage–/– male mice were used for this study. Disulfide (ds) and all thiol (at) form of HMGB1 were injected intrathecally (1 μg) and mechanical hypersensitivity assessed by von Frey filaments. Lumbar spinal cords were collected after i.t. injection of atHMGB1 and ds HMGB1 and mRNA levels for cytokine and glia markers assessed by quantitative PCR. Results In Balb/c and C57Bl/6 WT mice, i.t injection of dsHMGB1, but not atHMGB1, led to a significant reduction in mechanical thresholds. dsHMGB1 induced mechanical hypersensitivity 6 h after i.t. injection, which lasted for 5 days, compared to i.t. injection of saline. When dsHMGB1 was injected i.t. to Tlr4 deficient mice it did not induce mechanical hypersensitivity. In contrast Tlr2 and Rage deficient mice were still susceptible to dsHMGB1-induced mechanical hypersensitivity. Analysis of mRNA for cytokines and glial cell-associated factors in lumbar spinal cords revealed increased levels of Tnf, Ccl2, Cxcl1, Cxcl2, Gfap and Cd11b in mice injected with dsHMGB1, but not atHMGB1, with exception for Il1β and Cxcr3 that was induced also by atHMGB1. Intrathecal injection of dsHMGB1 to Tlr4–/– deficient mice, did not increase mRNA levels for Tnf, Il1β, Ccl2, Gfap and Cd11b. Conclusions We found the i.t. injection of the disulfide, but not the all-thiol, form of HMGB1 to induce pronouncedand long-lasting mechanical hypersensitivity, glial reactivity and cytokine induction in a TLR4-, but not TLR2- or RAGE-dependent manner. Thus our data indicates that, the redox state of HMGB1 is key for determining its nociceptive property and receptor usage and thus also the functional consequences of HMGB1 release. Agents interfering with extracellular HMGB1 may be considered in the development of new pain relieving therapeutics.

Differential requirement for A2a and A3 adenosine receptors for the protective effect of inosine in vivo

Blood ◽  
2003 ◽  
Vol 102 (13) ◽  
pp. 4472-4478 ◽  
Author(s):  
Gregorio Gomez ◽  
Michail V. Sitkovsky
Keyword(s):  
Protective Effect ◽  
Adenosine Receptors ◽  
Tissue Damage ◽  
Wild Type ◽  
In Vivo Models ◽  
Inflammatory Conditions ◽  
Severe Liver Damage ◽  
Lung Tissue Damage ◽  
Deficient Mice

AbstractInosine is an endogenous nucleoside with immunosuppressive properties that is known to inhibit the accumulation of proinflammatory cytokines and protect mice from endotoxin-induced inflammation and lung tissue damage. There are no known receptors specific for inosine, but A3 adenosine receptors (A3Rs) have been shown to bind inosine, resulting in mast cell degranulation and increased vascular permeability. The present study specifically addresses the requirement for A2aR and/or A3R for the protective effect of inosine in 2 experimental in vivo models of inflammatory disease. The data show that A3R is essential for protection against ConA-induced fulminant hepatitis since only A3R-expressing mice were protected by inosine whereas wild-type and A2aR-deficient mice exhibited severe liver damage even after administration of inosine. In addition, we show in a model of LPS-induced endotoxemia that inosine protected both A2aR-/- and A3R-/- mice from inflammation, but not A2aA3R double-null mice, indicating that in this model both A2aR and A3R were used by inosine. Thus, we demonstrate that A2a and A3 adenosine receptors are differentially utilized by inosine for the down-regulation of tissue damage under different inflammatory conditions in vivo. (Blood. 2003;102:4472-4478)

scholarly journals Assay Optimization and Screening of RNA-Protein Interactions by AlphaScreen

2007 ◽  
Vol 12 (7) ◽  
pp. 946-955 ◽  
Author(s):  
Nicholas L. Mills ◽  
Anang A. Shelat ◽  
R. Kiplin Guy
Keyword(s):  
Drug Discovery ◽  
Small Molecules ◽  
High Throughput ◽  
Protein Interactions ◽  
Proof Of Concept ◽  
Rna Molecules ◽  
Lead Compounds ◽  
Assay Optimization ◽  
Rna Targets ◽  
Hiv 1

The lack of lead compounds that specifically recognize and manipulate the function of RNA molecules limits our ability to consider RNA targets valid for drug discovery. Herein is reported a high-throughput biochemical screen for inhibitors of RNA-protein interactions based on AlphaScreen technology that incorporates several layers of specificity measurements into the primary screen. This screen was used to analyze approximately 5500 compounds from a collection of bioactive small molecules to detect inhibitors of the HIV-1 Rev-RRE and BIV Tat-TAR interactions. This proof-of-concept screen validates the assay as one that accurately identifies hit molecules and determines the selectivity of those hits. ( Journal of Biomolecular Screening 2007: 946-955)

Proteomic profiling in Lipocalin 2 deficient mice under normal and inflammatory conditions

2013 ◽  
Vol 78 ◽  
pp. 188-196 ◽  
Author(s):  
Kirsten Labbus ◽  
Marc Henning ◽  
Erawan Borkham-Kamphorst ◽  
Cordelia Geisler ◽  
Thorsten Berger ◽  
...  
Keyword(s):  
Lipocalin 2 ◽  
Proteomic Profiling ◽  
Inflammatory Conditions ◽  
Deficient Mice

scholarly journals Ex Vivo Enteroids Recapitulate In Vivo Citrulline Production in Mice

2018 ◽  
Vol 148 (9) ◽  
pp. 1415-1420 ◽  
Author(s):  
Xiaoying Wang ◽  
Yang Yuan ◽  
Inka C Didelija ◽  
Mahmoud A Mohammad ◽  
Juan C Marini
Keyword(s):  
Ex Vivo ◽  
Transcript Abundance ◽  
Mutant Mice ◽  
Ex Vivo Model ◽  
Endogenous Production ◽  
Gene Coding ◽  
Cycle Disorders ◽  
Deficient Mice

Abstract Background The endogenous production of arginine relies on the synthesis of citrulline by enteral ornithine transcarbamylase (OTC). Mutations in the gene coding for this enzyme are the most frequent cause of urea cycle disorders. There is a lack of correlation between in vivo metabolic function and DNA sequence, transcript abundance, or in vitro enzyme activity. Objective The goal of the present work was to test the hypothesis that enteroids, a novel ex vivo model, are able to recapitulate the in vivo citrulline production of wild-type (WT) and mutant mice. Methods Six-week-old male WT and OTC-deficient mice [sparse fur and abnormal skin (spf-ash) mutation] were studied. Urea and citrulline fluxes were determined in vivo, and OTC abundance was measured in liver and gut tissue. Intestinal crypts were isolated and cultured to develop enteroids. Ex vivo citrulline production and OTC abundance were determined in these enteroids. Results Liver OTC abundance was lower (mean ± SE: 0.16 ± 0.01 compared with 1.85 ± 0.18 arbitrary units; P < 0.001) in spf-ash mice than in WT mice, but there was no difference in urea production. In gut tissue, OTC was barely detectable in mutant mice; despite this, a lower but substantial citrulline production (67 ± 3 compared with 167 ± 8 µmol · kg−1 · h−1; P < 0.001) was shown in the mutant mice. Enteroids recapitulated the in vivo findings of a very low OTC content accompanied by a reduced citrulline production (1.07 ± 0.20 compared with 4.64 ± 0.44 nmol · µg DNA−1 · d−1; P < 0.001). Conclusions Enteroids recapitulate in vivo citrulline production and offer the opportunity to study the regulation of citrulline production in a highly manipulable system.

Sign in / Sign up

Export Citation Format

Share Document