Hydromethylthionine rescues synaptic SNARE proteins in a mouse model of tauopathies : interference by cholinesterase inhibitors

The authors acknowledge Malgorzata Wydrych and Joanna Lewandowska for the technical support with perfusion of mice and collection of brains, and of Soumya Palliyil Soman for the development of the s1D12 antibody.Peer reviewe

Differential compartmental processing and phosphorylation of pathogenic human tau and native mouse tau in the Line 66 model of frontotemporal dementia

Funding Information: Funding and additional information—This work was supported by EMPIR programme in Research Project 15HLT02 ReMiND cofinanced by the Participating States and the European Union's Horizon 2020 research and innovation programme (to N. L.). Work was also supported by WisTa Laboratories Ltd. (to V. M., D. L., M. M., C. R. H., G. R., C. M. W., F. T., and K. S.). Conflict of interest—This work was sponsored by WisTa Laboratories Ltd., an affiliate of TauRx Therapeutics Ltd. C. R. H. and C. M. W. are employees and officers of TauRx Therapeutics Ltd.Peer reviewedPublisher PD

Mechanisms of anticholinesterase interference with tau aggregation inhibitor activity in a tau-transgenic mouse model

AVAILABILITY OF DATA AND MATERIALS The data that support the findings of this study are available from the corresponding author [CMW], upon reasonable request. FUNDING This study was sponsored entirely by WisTa Laboratories Ltd. under the following grants: PAR1395, PAR1561, PAR1562, PAR1577 and PAR1763. The sponsor was involved in the design of the study; in the collection, analysis and interpretation of data; and in the writing of the report. The corresponding author had full access to all the data and had final responsibility for submission of the report for publication.Peer reviewedPostprin

Prävention eines kardialen Remodelings nach experimentellem Myokardinfarkt. Die Rolle der Angiotensin II Typ 2 Rezeptor Stimulation und der Modulation der MMP/TIMP Achse

This work summarizes our observations on the prevention of cardiac remodelling after experimental myocardial infarction (MI). MI remains a leading cause of morbidity and mortality worldwide and hence requires further therapeutic investigations. In the late phase of MI, adverse post-ischemic cardiac remodeling is characterized by fibrotic processes, collagen deposition and extracellular matrix degradation. The cardiac renin-angiotensin-aldosterone system (RAAS) plays an important role in post-ischemic pathological processes via AT1 receptor subtype (AT1R) activation. The AT2 receptor (AT2R) counteracts the AT1R. Therefore, we studied the effects of the AT2R stimulation by the direct non-peptide agonist C21 in the experimental model of MI in the rat 6 weeks after coronary artery ligation (P1). Treatment with C21 prevented left ventricular dilatation and dysfunction as evidenced by an improvement of cardiac systolic and diastolic parameters. Moreover, the AT2R stimulation decreased interstitial fibrosis and collagen accumulation. The anti-fibrotic effect was associated with a down-regulation of the pro-fibrotic cytokine Transforming Growth Factor beta 1 (TGF-β1) in the heart. Increased matrix metalloproteinase 9 (MMP9) levels and decreased tissue inhibitor of metalloproteases 1 (TIMP1) protein evidenced the proteolytic dysbalance. This dysbalance was ameliorated by C21 by activating TIMP1 which, in turn, inhibited MMP9. Collectively, these findings provide evidence of cardioprotective effects of the AT2R stimulation in the late phase post MI. The second study (P2) investigated the effects of the selective cannabinoid-1 receptor (CB1R) antagonist rimonabant in the rat model of MI and experimental metabolic syndrome. Blocking of the CB1R improved systolic and diastolic cardiac functions in the early and late stage after myocardial infarction, decreased pulse wave reflections and reduced cardiac remodelling. Importantly, CB1R blockade was also cardioprotective in rats with metabolic syndrome. Inhibition of proteolysis and decreased collagen accumulation due to reduced expression of TGF-β1 are the main mechanisms involved in the protective action of CB1 receptor blockade in the heart. We have also investigated the role of the kallikrein-kininogen-kinin system in the regulation of MMPs and TIMPs (P3). The cleaved form of high molecular weight kininogen (HKa) regulated the expression of MMP9, MMP2 and TIMPs in vascular smooth muscle cells. HKa reduced the IL-1α-stimulated release of MMP9 and MMP2.  These results demonstrate that HKa affects the regulation of MMPs/TIMPs axis. Hence, HKa may also be a potential drug target for treatment of cardiovascular diseases. In summary, modulating of cardiac MMPs/TIMPs axis and prevention of TGF-β1 associated fibrosis obviate left ventricular remodelling and promote functional improvement after MI.Diese Arbeit fasst unsere Beobachtungen über die Prävention von kardialem Remodeling nach experimentellem Myokardinfarkt zusammen. Herzinfarkt stellt die Hauptursache für Morbidität und Mortalität weltweit dar und erfordert weitere therapeutische Untersuchungen. In der Spätphase des Herzinfarktes ist postischämisches kardiales Remodeling durch fibrotische Prozesse, Kollagenablagerung und extrazelluläre Matrixdegradation gekennzeichnet. Das kardiale Renin-Angiotensin-Aldosteron-System (RAAS) spielt eine wichtige Rolle in den postischämischen pathologischen Prozessen durch die AT1-Rezeptor-Subtyp (AT1R) Aktivierung. Der AT2-Rezeptor (AT2R) wirkt dem AT1R entgegen. Daher untersuchten wir die Effekte der Stimulation mit dem direkten nicht- peptidischen AT2R-Agonist C21 in einem experimentellen Infarkt-Modell in Ratten 6 Wochen nach Koronararterien-Ligatur (P1). Die Therapie mit C21 hat die Dilatation des linken Ventrikels und die Dysfunktion durch eine Verbesserung der kardialen systolischen und diastolischen Parameter unterbunden. Außerdem verringerte die AT2R Stimulation die interstitielle Fibrose und Kollagenakkumulation. Die antifibrotische Wirkung war mit einer Hemmung des pro-fibrotischen Zytokins Transforming growth factor β1 (TGF-β1) im Herzgewebe assoziiert. Erhöhte Matrix-Metalloproteinase 9 (MMP9)-Niveaus und eine reduzierte Tissue inhibitor of metalloproteases 1 (TIMP1)-Expression auf Proteinebene belegten die proteolytische Dysbalance im postischämischen Herzgewebe. Dieses Ungleichgewicht wurde mit C21 durch TIMP1-Aktivierung, die wiederum MMP9 hemmte, verbessert. Zusammenfassend weisen diese Ergebnisse auf kardioprotektive Wirkungen der AT2R Stimulation in der Spätphase des Myokardinfarkts hin. Die zweite Studie (P2) untersuchte die Effekte des selektiven Cannabinoid-1-Rezeptor (CB1R) Antagonisten Rimonabant im Rattenmodell eines MI und eines experimentellen metabolischen Syndroms. Die Blockade des CB1R verbesserte die systolischen und diastolischen Herzfunktionen in der frühen und späten Phase nach MI, reduzierte die Pulswellenreflexionen und das kardiale Remodeling. Wichtig ist, dass die CB1R Blockade auch kardioprotektiv bei Ratten mit metabolischem Syndrom Wirkung zeigte.  Die Hemmung der Proteolyse und die verminderte Kollagenakkumulation durch reduzierte TGF-β1-Expression stellen die Hauptmechanismen der Schutzwirkung der CB1-Rezeptor-Blockade im Herz dar. Die Rolle des Kallikrein- Kininogen-Kinin Systems in der Regulation von MMPs und TIMPs wurde auch untersucht (P3). Die gespaltene Form von hochmolekularem Kininogen (HKa) regulierte die Genexpression des MMP9, MMP2 und TIMPs in glatten Gefäßmuskelzellen. HKa verminderte die IL-1α-stimulierte MMP9 und MMP2- Freisetzung. Diese Ergebnisse zeigten, dass HKa die MMPs/TIMPs-Achse moduliert. Daher kann HKa auch als mögliches Zielmolekül für die Behandlung von kardiovaskulären Krankheiten dienen. Zusammenfassend eliminiert die Modulation der kardialen MMPs/TIMPs-Achse und die Prävention von TGF-β1- assoziierter Fibrose das linksventrikuläre kardiale Remodeling und fördert die Funktionsverbesserung nach einem Myokardinfarkt

The (pro)renin receptor mediates constitutive PLZF-independent pro-proliferative effects which are inhibited by bafilomycin but not genistein

The (pro)renin receptor [(P)RR] is crucial for cardio-renal pathophysiology. The distinct molecular mechanisms of this receptor are still incompletely understood. The (P)RR is able to interact with different signalling proteins such as promyelocytic leukemia zinc finger protein (PLZF) and Wnt receptors. Moreover, domains of the (P)RR are essential for V-ATPase activity. V-ATPase- and Wnt-mediated effects imply constitutive, i.e., (pro)renin-independent functions of the (P)RR. Regarding ligand-dependent (P)RR signalling, the role of prorenin glycosylation is currently unknown. Therefore, the aim of this study was to analyse the contribution of constitutive (P)RR activity to its cellular effects and the relevance of prorenin glycosylation on its ligand activity. We were able to demonstrate that high glucose induces (P)RR signal transduction whereas deglycosylation of prorenin abolishes its intrinsic activity in neuronal and epithelial cells. By using siRNA against (P)RR or PLZF as well as the PLZF translocation blocker genistein and the specific V-ATPase inhibitor bafilomycin, we were able to dissect three distinct sub-pathways downstream of the (P)RR. The V-ATPase function is ligand-independently associated with strong pro-proliferative effects whereas prorenin causes moderate proliferation in vitro. In contrast, PLZF per se [i.e., in the absence of (pro)renin] does not interfere with cell number

Cannabinoid receptor 1 inhibition improves cardiac function and remodelling after myocardial infarction and in experimental metabolic syndrome

The cannabinoid receptors, CB1 and CB2, are expressed in the heart, but their role under pathological conditions remains controversial. This study examined the effect of CB1 receptor blockade on cardiovascular functions after experimental MI and in experimental metabolic syndrome. MI was induced in Wistar rats by permanent ligation of the left coronary artery. Treatment with the CB1 receptor antagonist rimonabant (10 mg/kg i.p. daily) started 7 days before or 6 h after MI and continued for 6 weeks. Haemodynamic parameters were measured via echocardiography and intracardiac Samba catheter. CB1 blockade improved systolic and diastolic heart function, decreased cardiac collagen and hydroxyproline content and down-regulated TGF-beta 1. Additionally, rimonabant decreased arterial stiffness, normalised QRS complex duration and reduced brain natriuretic peptide levels in serum. In primary cardiac fibroblasts, rimonabant decreased MMP-9 activity and TGF-beta 1 expression. Furthermore, rimonabant improved depressed systolic function of spontaneously hypertensive obese rats and reduced weight gain. Blocking of CB1 receptor with rimonabant improves cardiac functions in the early and late stages after MI, decreases arterial stiffness and reduces cardiac remodelling. Rimonabant also has cardioprotective actions in rats characterised by the metabolic syndrome. Inhibition of proteolysis and TGF-beta 1 expression and reduced collagen content by rimonabant may attenuate destruction of the extracellular matrix and decrease fibrosis after MI

Immunoproteasome subunit ß5i/LMP7-deficiency in atherosclerosis

Abstract Management of protein homeostasis by the ubiquitin-proteasome system is critical for atherosclerosis development. Recent studies showed controversial results on the role of immunoproteasome (IP) subunit β5i/LMP7 in maintenance of protein homeostasis under cytokine induced oxidative stress. The present study aimed to investigate the effect of β5i/LMP7-deficiency on the initiation and progression of atherosclerosis as a chronic inflammatory, immune cell driven disease. LDLR−/−LMP7−/− and LDLR−/− mice were fed a Western-type diet for either 6 or 24 weeks to induce early and advanced stage atherosclerosis, respectively. Lesion burden was similar between genotypes in both stages. Macrophage content and abundance of polyubiquitin conjugates in aortic root plaques were unaltered by β5i/LMP7-deficiency. In vitro experiments using bone marrow-derived macrophages (BMDM) showed that β5i/LMP7-deficiency did not influence macrophage polarization or accumulation of polyubiquitinated proteins and cell survival upon hydrogen peroxide and interferon-γ treatment. Analyses of proteasome core particle composition by Western blot revealed incorporation of standard proteasome subunits in β5i/LMP7-deficient BMDM and spleen. Chymotrypsin-, trypsin- and caspase-like activities assessed by using short fluorogenic peptides in BMDM whole cell lysates were similar in both genotypes. Taken together, deficiency of IP subunit β5i/LMP7 does not disturb protein homeostasis and does not aggravate atherogenesis in LDLR−/− mice