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Molecular Neurodegeneration Jun 2024LRRK2-targeting therapeutics that inhibit LRRK2 kinase activity have advanced to clinical trials in idiopathic Parkinson's disease (iPD). LRRK2 phosphorylates Rab10 on...
BACKGROUND
LRRK2-targeting therapeutics that inhibit LRRK2 kinase activity have advanced to clinical trials in idiopathic Parkinson's disease (iPD). LRRK2 phosphorylates Rab10 on endolysosomes in phagocytic cells to promote some types of immunological responses. The identification of factors that regulate LRRK2-mediated Rab10 phosphorylation in iPD, and whether phosphorylated-Rab10 levels change in different disease states, or with disease progression, may provide insights into the role of Rab10 phosphorylation in iPD and help guide therapeutic strategies targeting this pathway.
METHODS
Capitalizing on past work demonstrating LRRK2 and phosphorylated-Rab10 interact on vesicles that can shed into biofluids, we developed and validated a high-throughput single-molecule array assay to measure extracellular pT73-Rab10. Ratios of pT73-Rab10 to total Rab10 measured in biobanked serum samples were compared between informative groups of transgenic mice, rats, and a deeply phenotyped cohort of iPD cases and controls. Multivariable and weighted correlation network analyses were used to identify genetic, transcriptomic, clinical, and demographic variables that predict the extracellular pT73-Rab10 to total Rab10 ratio.
RESULTS
pT73-Rab10 is absent in serum from Lrrk2 knockout mice but elevated by LRRK2 and VPS35 mutations, as well as SNCA expression. Bone-marrow transplantation experiments in mice show that serum pT73-Rab10 levels derive primarily from circulating immune cells. The extracellular ratio of pT73-Rab10 to total Rab10 is dynamic, increasing with inflammation and rapidly decreasing with LRRK2 kinase inhibition. The ratio of pT73-Rab10 to total Rab10 is elevated in iPD patients with greater motor dysfunction, irrespective of disease duration, age, sex, or the usage of PD-related or anti-inflammatory medications. pT73-Rab10 to total Rab10 ratios are associated with neutrophil degranulation, antigenic responses, and suppressed platelet activation.
CONCLUSIONS
The extracellular serum ratio of pT73-Rab10 to total Rab10 is a novel pharmacodynamic biomarker for LRRK2-linked innate immune activation associated with disease severity in iPD. We propose that those iPD patients with higher serum pT73-Rab10 levels may benefit from LRRK2-targeting therapeutics that mitigate associated deleterious immunological responses.
Topics: Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Parkinson Disease; Animals; Humans; Mice; Rats; rab GTP-Binding Proteins; Inflammation; Female; Phosphorylation; Mice, Transgenic; Male; Middle Aged; Aged; Severity of Illness Index
PubMed: 38862989
DOI: 10.1186/s13024-024-00738-4 -
Molecular Therapy : the Journal of the... Jun 2024This study demonstrates the potential of using biological nanoparticles to deliver RNA therapeutics targeting programmed death-ligand 1 (PD-L1) as a treatment strategy...
This study demonstrates the potential of using biological nanoparticles to deliver RNA therapeutics targeting programmed death-ligand 1 (PD-L1) as a treatment strategy for cholangiocarcinoma (CCA). RNA therapeutics offer prospects for intracellular immune modulation, but effective clinical translation requires appropriate delivery strategies. Milk-derived nanovesicles were decorated with epithelial cellular adhesion molecule (EpCAM) aptamers and used to deliver PD-L1 small interfering RNA (siRNA) or Cas9 ribonucleoproteins directly to CCA cells. In vitro, nanovesicle treatments reduced PD-L1 expression in CCA cells while increasing degranulation, cytokine release, and tumor cell cytotoxicity when tumor cells were co-cultured with T cells or natural killer cells. Similarly, immunomodulation was observed in multicellular spheroids that mimicked the tumor microenvironment. Combining targeted therapeutic vesicles loaded with siRNA to PD-L1 with gemcitabine effectively reduced tumor burden in an immunocompetent mouse CCA model compared with controls. This proof-of-concept study demonstrates the potential of engineered targeted nanovesicle platforms for delivering therapeutic RNA cargoes to tumors, as well as their use in generating effective targeted immunomodulatory therapies for difficult-to-treat cancers such as CCA.
PubMed: 38859589
DOI: 10.1016/j.ymthe.2024.06.006 -
Cellular Physiology and Biochemistry :... May 2024Adrenaline quickly inhibits the release of histamine from mast cells. Besides β2-adrenergic receptors, several in vitro studies also indicate the involvement of...
BACKGROUND/AIMS
Adrenaline quickly inhibits the release of histamine from mast cells. Besides β2-adrenergic receptors, several in vitro studies also indicate the involvement of α-adrenergic receptors in the process of exocytosis. Since exocytosis in mast cells can be detected electrophysiologically by the changes in the membrane capacitance (Cm), its continuous monitoring in the presence of drugs would determine their mast cell-stabilizing properties.
METHODS
Employing the whole-cell patch-clamp technique in rat peritoneal mast cells, we examined the effects of adrenaline on the degranulation of mast cells and the increase in the Cm during exocytosis. We also examined the degranulation of mast cells in the presence or absence of α-adrenergic receptor agonists or antagonists.
RESULTS
Adrenaline dose-dependently suppressed the GTP-γ-S-induced increase in the Cm and inhibited the degranulation from mast cells, which was almost completely erased in the presence of butoxamine, a β2-adrenergic receptor antagonist. Among α-adrenergic receptor agonists or antagonists, high dose prazosin, a selective α1-adrenergic receptor antagonist, significantly reduced the ratio of degranulating mast cells and suppressed the increase in the Cm. Additionally, prazosin augmented the inhibitory effects of adrenaline on the degranulation of mast cells.
CONCLUSION
This study provided electrophysiological evidence for the first time that adrenaline dose-dependently inhibited the process of exocytosis, confirming its usefulness as a potent mast cell-stabilizer. The pharmacological blockade of α1-adrenergic receptor by prazosin synergistically potentiated such mast cell-stabilizing property of adrenaline, which is primarily mediated by β2-adrenergic receptors.
Topics: Animals; Mast Cells; Epinephrine; Rats; Prazosin; Cell Degranulation; Male; Exocytosis; Patch-Clamp Techniques; Adrenergic alpha-1 Receptor Antagonists; Rats, Wistar
PubMed: 38852193
DOI: 10.33594/000000703 -
BMJ Open Jun 2024Perioperative anaphylaxis (POA) can lead to significant complications. Therefore, accurate identification of allergens for POA patients is critical to ensure the safety...
INTRODUCTION
Perioperative anaphylaxis (POA) can lead to significant complications. Therefore, accurate identification of allergens for POA patients is critical to ensure the safety of future surgical and anaesthetic procedures. Existing perioperative allergen detection methods face challenges in sensitivity and specificity. The passive mast cell activation test (pMAT) has recently emerged as a potential diagnostic tool. Our study aims to evaluate the diagnostic efficacy of pMAT for identifying perioperative allergens, with a focus on non-depolarising neuromuscular blocking agents, the most common culprits of POA.
METHODS AND ANALYSIS
This prospective diagnostic accuracy study will measure the diagnostic accuracy of pMAT in POA patients. Participants will undergo skin testing (ST), basophil activation testing (BAT) and pMAT. The diagnostic validity of pMAT will be assessed based on the results of ST and BAT. The assessment of diagnostic accuracy will include sensitivity, specificity, likelihood ratios, and false-positive and false-negative rates while measurement of the consistency rate will assess reliability.
ETHICS AND DISSEMINATION
This study has been approved by the Institutional Review Board of China-Japan Friendship Hospital (2023-KY-247). Results will be disseminated through academic presentations and peer-reviewed journal publications and will provide valuable scientific data and some new insights into the diagnostic accuracy of pMAT.
Topics: Humans; Anaphylaxis; Prospective Studies; Allergens; Reproducibility of Results; Mast Cells; Skin Tests; Neuromuscular Blocking Agents; Sensitivity and Specificity; Basophil Degranulation Test; Perioperative Period
PubMed: 38851228
DOI: 10.1136/bmjopen-2024-085212 -
Biomolecules & Therapeutics Jul 2024Apoptosis signal-regulating kinase 1 (ASK1) is an upstream signaling molecule in oxidative stress-induced responses. Because oxidative stress is involved in asthma...
Apoptosis signal-regulating kinase 1 (ASK1) is an upstream signaling molecule in oxidative stress-induced responses. Because oxidative stress is involved in asthma pathogenesis, ASK1 gene deficiency was investigated in animal models of allergic asthma. However, there is no study to investigate whether ASK1 inhibitors could be applied for asthma to date. Selonsertib, a potent and selective ASK1 inhibitor, was applied to BALB/c mice of an ovalbumin (OVA)-induced allergic asthma model. Selonsertib suppressed antigen-induced degranulation of RBL-2H3 mast cells in a concentration-dependent manner. The administration of selonsertib both before OVA sensitization and OVA challenge significantly reduced airway hyperresponsiveness, and suppressed eosinophil numbers and inflammatory cytokine levels in the bronchoalveolar lavage fluid. Histopathologic examination elucidated less inflammatory responses and reduced mucin-producing cells around the peribronchial regions of the lungs. Selonsertib also suppressed the IgE levels in serum and the protein levels of IL-13 in the bronchoalveolar lavage fluid. These results suggest that selonsertib may ameliorate allergic asthma by suppressing immune responses and be applicable to allergic asthma.
PubMed: 38844790
DOI: 10.4062/biomolther.2023.203 -
Journal of Nuclear Medicine : Official... Jul 2024Natural killer (NK) cells can kill cancer cells via antibody-dependent cell-mediated cytotoxicity (ADCC): a tumor-associated IgG antibody binds to the Fcγ receptor CD16...
Natural killer (NK) cells can kill cancer cells via antibody-dependent cell-mediated cytotoxicity (ADCC): a tumor-associated IgG antibody binds to the Fcγ receptor CD16 on NK cells via the antibody Fc region and activates the cytotoxic functions of the NK cell. Here, we used PET imaging to assess NK cell migration to human epidermal growth factor receptor 2 (HER2)-positive HCC1954 breast tumors, examining the influence of HER2-targeted trastuzumab antibody treatment on NK cell tumor accumulation. Human NK cells from healthy donors were expanded ex vivo and labeled with [Zr]Zr-oxine. In vitro experiments compared the phenotypic markers, viability, proliferation, migration, degranulation, and ADCC behaviors of both labeled (Zr-NK) and unlabeled NK cells. Female mice bearing orthotopic human breast HCC1954 tumors were administered Zr-NK cells alongside trastuzumab treatment or a sham treatment and then scanned using PET/CT imaging over 7 d. Flow cytometry and γ-counting were used to analyze the presence of Zr-NK cells in liver and spleen tissues. Zr cell radiolabeling yields measured 42.2% ± 8.0%. At an average specific activity of 16.7 ± 4.7 kBq/10 cells, Zr-NK cells retained phenotypic and functional characteristics including CD56 and CD16 expression, viability, migration, degranulation, and ADCC capabilities. In vivo PET/CT studies indicated predominant accumulation of Zr-NK cells in the liver and spleen. Ex vivo analyses of liver and spleen tissues indicated that the administered human Zr-NK cells retained their radioactivity in vivo and that Zr did not transfer to cells of murine soft tissues, thus validating this Zr PET method for NK cell tracking. Notably, Zr-NK cells migrated to HER2-positive tumors, both with and without trastuzumab treatment. Trastuzumab treatment was associated with an increased Zr-NK cell signal at days 1 and 3 after injection. In vitro, Zr-NK cells maintained key cellular and cytotoxic functions. In vivo, Zr-NK cells trafficked to HER2-postive tumors, with trastuzumab treatment correlating with enhanced Zr-NK infiltration. This study demonstrates the feasibility of using PET to image Zr-NK cell infiltration into solid tumors.
Topics: Killer Cells, Natural; Zirconium; Animals; Mice; Humans; Radioisotopes; Female; Cell Line, Tumor; Trastuzumab; Positron Emission Tomography Computed Tomography; Receptor, ErbB-2; Positron-Emission Tomography; Isotope Labeling; Cell Movement; Breast Neoplasms
PubMed: 38844362
DOI: 10.2967/jnumed.124.267876 -
Allergy Jun 2024
PubMed: 38841822
DOI: 10.1111/all.16190 -
Haematologica Jun 2024Philadelphia chromosome-positive B-cell precursor acute lymphoblastic leukemia (Ph+ BCPALL) is a high-risk acute lymphoblastic leukemia subtype characterized by the...
Asciminib stands out as the superior tyrosine kinase inhibitor to combine with anti-CD20 monoclonal antibodies for the treatment of CD20+ Philadelphia-positive B-cell precursor acute lymphoblastic leukemia in preclinical models.
Philadelphia chromosome-positive B-cell precursor acute lymphoblastic leukemia (Ph+ BCPALL) is a high-risk acute lymphoblastic leukemia subtype characterized by the presence of BCR::ABL1 fusion gene. Tyrosine kinase inhibitors (TKIs) combined with chemotherapy are established as the first-line treatment. Additionally, rituximab (RTX), an anti-CD20 monoclonal antibody (mAb) is administered in adult BCP-ALL patients with ≥20% of CD20+ blasts. In this study, we observed a marked prevalence of CD20 expression in patients diagnosed with Ph+ BCP-ALL, indicating a potential widespread clinical application of RTX in combination with TKIs. Consequently, we examined the influence of TKIs on the antitumor effectiveness of anti-CD20 mAbs by evaluating CD20 surface levels and conducting in vitro functional assays. All tested TKIs were found to uniformly downregulate CD20 on leukemic cells, diminishing the efficacy of RTX-mediated complement-dependent cytotoxicity. Interestingly, these TKIs displayed varied effects on NK cell-mediated antibody-dependent cytotoxicity and macrophage phagocytic function. While asciminib demonstrated no inhibition of effector cell functions, dasatinib notably suppressed the anti-CD20-mAb-mediated NK cell cytotoxicity and macrophage phagocytosis of BCP-ALL cells. Dasatinib and ponatinib also decreased NK cell degranulation in vitro. Importantly, oral administration of dasatinib, but not asciminib, compromised NK cell activity within patients' blood, determined by ex vivo degranulation assay. Our results indicate that asciminib might be preferred over other TKIs for combination therapy with anti-CD20 mAbs.
PubMed: 38841802
DOI: 10.3324/haematol.2023.284853 -
Frontiers in Pharmacology 2024Ginseng leaves are known to contain high concentrations of bioactive compounds, such as ginsenosides, and have potential as a treatment for various conditions, including...
Ginseng leaves are known to contain high concentrations of bioactive compounds, such as ginsenosides, and have potential as a treatment for various conditions, including fungal infections, cancer, obesity, oxidative stress, and age-related diseases. This study assessed the impact of ginseng leaf extract (GLE) on mast cell-mediated allergic inflammation and atopic dermatitis (AD) in DNCB-treated mice. GLE reduced skin thickness and lymph node nodules and suppressed the expression and secretion of histamine and pro-inflammatory cytokines. It also significantly lowered the production of inflammatory response mediators including ROS, leukotriene C4 (LTC4), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). GLE inhibited the phosphorylation of MAPKs (ERK, P38, JNK) and the activation of NF-κB, which are both linked to inflammatory cytokine expression. We demonstrated that GLE's inhibitory effect on mast cell-mediated allergic inflammation is due to the blockade of the NF-κB and inflammasome pathways. Our findings suggest that GLE can be an effective therapeutic agent for mast-cell mediated and allergic inflammatory conditions.
PubMed: 38841363
DOI: 10.3389/fphar.2024.1403285 -
Drug Discoveries & Therapeutics Jun 2024This study aims to investigate the antiallergic effects of Shiikuwasha (Citrus depressa Hayata) leaf and peel extracts by examining the regulation of degranulation and...
Shiikuwasha leaf and peel extracts inhibit allergic reactions by suppressing degranulation in RBL-2H3 rat basophilic leukemia cells and immunoglobulin production in mouse spleen lymphocytes.
This study aims to investigate the antiallergic effects of Shiikuwasha (Citrus depressa Hayata) leaf and peel extracts by examining the regulation of degranulation and inflammatory cytokine production from rat basophilic leukemia (RBL-2H3) cells and antigen-specific antibody production in sensitized mouse spleen lymphocytes. In vivo antiallergic activity was evaluated using the passive cutaneous anaphylaxis (PCA) reaction model. Extracts of Shiikuwasha leaves and peel were prepared using 80% methanol and dissolved in dimethylsulfoxide. The dinitrophenyl-human serum albumin-induced β-hexosaminidase levels in immunoglobulin (Ig) E-sensitized RBL-2H3 cells were assessed using enzymatic assays. Cytokine production was measured by enzyme-linked immunosorbent assay. Antibody production capacity was evaluated using lymphocytes isolated from spleens of type I allergy model mice. Lymphocytes were cultured for 72 h with Shiikuwasha extracts, and ovalbumin-specific IgE, IgG1, and IgG2a levels were measured. Shiikuwasha leaf and peel extract significantly reduced β-hexosaminidase release and suppressed interleukin-4 and tumor necrosis factor-α production from RBL-2H3 cells. Ovalbumin-specific IgE and IgG1 production decreased in Shiikuwasha extract-treated lymphocytes. These extracts also significantly suppressed the PCA reaction. Shiikuwasha leaf and peel extract reduce degranulation in RBL-2H3 cells and antibody production in spleen-derived lymphocytes and therefore exhibit antiallergic effects.
PubMed: 38839286
DOI: 10.5582/ddt.2024.01016