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- ItemThe alarmin interleukin-1α triggers secondary degeneration through reactive astrocytes and endothelium after spinal cord injury([London] : Nature Publishing Group UK, 2022) Bretheau, Floriane; Castellanos-Molina, Adrian; Bélanger, Dominic; Kusik, Maxime; Mailhot, Benoit; Boisvert, Ana; Vallières, Nicolas; Lessard, Martine; Gunzer, Matthias; Liu, Xiaoyu; Boilard, Éric; Quan, Ning; Lacroix, SteveSpinal cord injury (SCI) triggers neuroinflammation, and subsequently secondary degeneration and oligodendrocyte (OL) death. We report that the alarmin interleukin (IL)−1α is produced by damaged microglia after SCI. Intra-cisterna magna injection of IL-1α in mice rapidly induces neutrophil infiltration and OL death throughout the spinal cord, mimicking the injury cascade seen in SCI sites. These effects are abolished through co-treatment with the IL-1R1 antagonist anakinra, as well as in IL-1R1-knockout mice which demonstrate enhanced locomotor recovery after SCI. Conditional restoration of IL-1R1 expression in astrocytes or endothelial cells (ECs), but not in OLs or microglia, restores IL-1α-induced effects, while astrocyte- or EC-specific Il1r1 deletion reduces OL loss. Conditioned medium derived from IL-1α-stimulated astrocytes results in toxicity for OLs; further, IL-1α-stimulated astrocytes generate reactive oxygen species (ROS), and blocking ROS production in IL-1α-treated or SCI mice prevented OL loss. Thus, after SCI, microglia release IL-1α, inducing astrocyte- and EC-mediated OL degeneration.
- ItemThe human TRPA1 intrinsic cold and heat sensitivity involves separate channel structures beyond the N-ARD domain([London] : Nature Publishing Group UK, 2022) Moparthi, Lavanya; Sinica, Viktor; Moparthi, Vamsi K.; Kreir, Mohamed; Vignane, Thibaut; Filipovic, Milos R.; Vlachova, Viktorie; Zygmunt, Peter M.TRP channels sense temperatures ranging from noxious cold to noxious heat. Whether specialized TRP thermosensor modules exist and how they control channel pore gating is unknown. We studied purified human TRPA1 (hTRPA1) truncated proteins to gain insight into the temperature gating of hTRPA1. In patch-clamp bilayer recordings, ∆1–688 hTRPA1, without the N-terminal ankyrin repeat domain (N-ARD), was more sensitive to cold and heat, whereas ∆1–854 hTRPA1, also lacking the S1–S4 voltage sensing-like domain (VSLD), gained sensitivity to cold but lost its heat sensitivity. In hTRPA1 intrinsic tryptophan fluorescence studies, cold and heat evoked rearrangement of VSLD and the C-terminus domain distal to the transmembrane pore domain S5–S6 (CTD). In whole-cell electrophysiology experiments, replacement of the CTD located cysteines 1021 and 1025 with alanine modulated hTRPA1 cold responses. It is proposed that hTRPA1 CTD harbors cold and heat sensitive domains allosterically coupled to the S5–S6 pore region and the VSLD, respectively.
- ItemGlycolytic flux control by drugging phosphoglycolate phosphatase([London] : Nature Publishing Group UK, 2022) Jeanclos, Elisabeth; Schlötzer, Jan; Hadamek, Kerstin; Yuan-Chen, Natalia; Alwahsh, Mohammad; Hollmann, Robert; Fratz, Stefanie; Yesilyurt-Gerhards, Dilan; Frankenbach, Tina; Engelmann, Daria; Keller, Angelika; Kaestner, Alexandra; Schmitz, Werner; Neuenschwander, Martin; Hergenröder, Roland; Sotriffer, Christoph; von Kries, Jens Peter; Schindelin, Hermann; Gohla, AntjeTargeting the intrinsic metabolism of immune or tumor cells is a therapeutic strategy in autoimmunity, chronic inflammation or cancer. Metabolite repair enzymes may represent an alternative target class for selective metabolic inhibition, but pharmacological tools to test this concept are needed. Here, we demonstrate that phosphoglycolate phosphatase (PGP), a prototypical metabolite repair enzyme in glycolysis, is a pharmacologically actionable target. Using a combination of small molecule screening, protein crystallography, molecular dynamics simulations and NMR metabolomics, we discover and analyze a compound (CP1) that inhibits PGP with high selectivity and submicromolar potency. CP1 locks the phosphatase in a catalytically inactive conformation, dampens glycolytic flux, and phenocopies effects of cellular PGP-deficiency. This study provides key insights into effective and precise PGP targeting, at the same time validating an allosteric approach to control glycolysis that could advance discoveries of innovative therapeutic candidates.
- ItemTargeting cardiomyocyte ADAM10 ectodomain shedding promotes survival early after myocardial infarction([London] : Nature Publishing Group UK, 2022) Klapproth, Erik; Witt, Anke; Klose, Pauline; Wiedemann, Johanna; Vavilthota, Nikitha; Künzel, Stephan R.; Kämmerer, Susanne; Günscht, Mario; Sprott, David; Lesche, Mathias; Rost, Fabian; Dahl, Andreas; Rauch, Erik; Kattner, Lars; Weber, Silvio; Mirtschink, Peter; Kopaliani, Irakli; Guan, Kaomei; Lorenz, Kristina; Saftig, Paul; Wagner, Michael; El-Armouche, AliAfter myocardial infarction the innate immune response is pivotal in clearing of tissue debris as well as scar formation, but exaggerated cytokine and chemokine secretion with subsequent leukocyte infiltration also leads to further tissue damage. Here, we address the value of targeting a previously unknown a disintegrin and metalloprotease 10 (ADAM10)/CX3CL1 axis in the regulation of neutrophil recruitment early after MI. We show that myocardial ADAM10 is distinctly upregulated in myocardial biopsies from patients with ischemia-driven cardiomyopathy. Intriguingly, upon MI in mice, pharmacological ADAM10 inhibition as well as genetic cardiomycyte-specific ADAM10 deletion improves survival with markedly enhanced heart function and reduced scar size. Mechanistically, abolished ADAM10-mediated CX3CL1 ectodomain shedding leads to diminished IL-1β-dependent inflammation, reduced neutrophil bone marrow egress as well as myocardial tissue infiltration. Thus, our data shows a conceptual insight into how acute MI induces chemotactic signaling via ectodomain shedding in cardiomyocytes.