Calpain inhibition by peptide epoxides.
Ontology highlight
ABSTRACT:
SUBMITTER: Parkes C
PROVIDER: S-EPMC1152644 | biostudies-other | 1985 Sep
REPOSITORIES: biostudies-other
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Project description:Over recent years, accumulated evidence suggests that autophagy induction is protective in animal models of a number of neurodegenerative diseases. Intense research in the field has elucidated different pathways through which autophagy can be upregulated and it is important to establish how modulation of these pathways impacts upon disease progression in vivo and therefore which, if any, may have further therapeutic relevance. In addition, it is important to understand how alterations in these target pathways may affect normal physiology when constitutively modulated over a long time period, as would be required for treatment of neurodegenerative diseases. Here we evaluate the potential protective effect of downregulation of calpains. We demonstrate, in Drosophila, that calpain knockdown protects against the aggregation and toxicity of proteins, like mutant huntingtin, in an autophagy-dependent fashion. Furthermore, we demonstrate that, overexpression of the calpain inhibitor, calpastatin, increases autophagosome levels and is protective in a mouse model of Huntington's disease, improving motor signs and delaying the onset of tremors. Importantly, long-term inhibition of calpains did not result in any overt deleterious phenotypes in mice. Thus, calpain inhibition, or activation of autophagy pathways downstream of calpains, may be suitable therapeutic targets for diseases like Huntington's disease.
| S-EPMC4326573 | biostudies-literature
Project description:Calpains are ubiquitous pro-inflammatory proteases, whose activity is controlled by calpastatin, their specific inhibitor. Transgenic mice over-expressing rabbit calpastatin (CalpTG) are protected against vascular remodelling and angiotensin II-dependent inflammation. We hypothesized that specific calpain inhibition would protect against aging-related lesions in arteries and kidneys. We analysed tissues from 2-months and 2-years-old CalpTG and wild-type mice and performed high throughput RNA-Sequencing of kidney tissue in aged mice. In addition, we analysed inflammatory response in the kidney of aged CalpTG and wild-type mice, and in both in vivo (monosodium urate peritonitis) and in vitro models of inflammation. At two years, CalpTG mice had preserved kidney tissue, less vascular remodelling and less markers of senescence than wild-type mice. Nevertheless, CalpTG mice lifespan was not extended, due to the development of lethal spleen tumors. Inflammatory pathways were less expressed in aged CalpTG mice, especially cytokines related to NF-κB and NLRP3 inflammasome activation. CalpTG mice had reduced macrophage infiltration with aging and CalpTG mice produced less IL-1α and IL-1β in vivo in response to inflammasome activators. In vitro, macrophages from CalpTG mice produced less IL-1α in response to particulate activators of inflammasome. Calpains inhibition protects against inflammaging, limiting kidney and vascular lesions related to aging.
| S-EPMC5556007 | biostudies-other
Project description:Neurologic complications associated with viral encephalitis, including seizures and cognitive impairment, are a global health issue, especially in children. We previously showed that hippocampal injury during acute picornavirus infection in mice is associated with calpain activation and is the result of neuronal death triggered by brain-infiltrating inflammatory monocytes. We therefore hypothesized that treatment with a calpain inhibitor would protect neurons from immune-mediated bystander injury. C57BL/6J mice infected with the Daniel's strain of Theiler's murine encephalomyelitis virus were treated with the FDA-approved drug ritonavir using a dosing regimen that resulted in plasma concentrations within the therapeutic range for calpain inhibition. Ritonavir treatment significantly reduced calpain activity in the hippocampus, protected hippocampal neurons from death, preserved cognitive performance, and suppressed seizure escalation, even when therapy was initiated 36 hours after disease onset. Calpain inhibition by ritonavir may be a powerful tool for preserving neurons and cognitive function and preventing neural circuit dysregulation in humans with neuroinflammatory disorders.
| S-EPMC4921808 | biostudies-literature
Project description:ObjectivesCalpain activation during ischemia is known to play critical roles in myocardial remodeling. We hypothesize that calpain inhibition (CI) may serve to reverse and/or prevent fibrosis in chronically ischemic myocardium.MethodsYorkshire swine were fed a high-cholesterol diet for 4 weeks followed by placement of an ameroid constrictor on the left circumflex artery to induce myocardial ischemia. 3 weeks later, animals received either: no drug; high-cholesterol control group (CON; n = 8); low-dose CI (0.12 mg/kg; LCI, n = 9); or high-dose CI (0.25 mg/kg; HCI, n = 8). The high-cholesterol diet and CI were continued for 5 weeks, after which myocardial tissue was harvested. Tissue samples were analyzed by western blot for changes in protein content.ResultsIn the setting of hypercholesterolemia and chronic myocardial ischemia, CI decreased the expression of collagen in ischemic and nonischemic myocardial tissue. This reduced collagen content was associated with a corresponding decrease in Jak/STAT/MCP-1 signaling pathway, suggesting a role for Jak 2 signaling in calpain activity. CI also decreases the expression of focal adhesion proteins (vinculin) and stabilizes the expression of cytoskeletal and structural proteins (N-cadherin, α-fodrin, desmin, vimentin, filamin, troponin-I). CI had no significant effect on metabolic and hemodynamic parameters.ConclusionsCalpain inhibition may be a beneficial medical therapy to decrease collagen formation in patients with coronary artery disease and associated comorbidities.
| S-EPMC7529741 | biostudies-literature
Project description:Background:The molecular pattern of severe burn-induced acute lung injury, characterized by cell structure damage and leukocyte infiltration, remains unknown. This study aimed to determine whether calpain, a protease involved in both processes, mediates severe burn-induced acute lung injury. Methods:Rats received full-thickness scald burns covering 30% of the total body surface area, followed by instant fluid resuscitation. MDL28170 (Tocris Bioscience), an inhibitor of calpain, was given intravenously 1 h before or after the scald burn. The histological score, wet/dry weight ratio, and caspase-3 activity were examined to evaluate the degree of lung damage. Calpain activity and its source were detected by an assay kit and immunofluorescence staining. The proteolysis of membrane skeleton proteins ?-fodrin and ankyrin-B, which are substrates of calpain, was measured by Western blot. Results:Time-course studies showed that tissue damage reached a peak between 1 and 6 h post-scald burn and gradually diminished at 24 h. More importantly, calpain activity reached peak levels at 1 h and was maintained until 24 h, paralleled by lung damage to some extent. Western blot showed that the levels of the proteolyzed forms of ?-fodrin and ankyrin-B correlated well with the degree of damage. MDL28170 at a dose of 3 mg/kg b. w. given 1 h before burn injury not only antagonized the increase in calpain activity but also ameliorated scald burn-induced lung injury, including the degradation of ?-fodrin and ankyrin-B. Immunofluorescence images revealed calpain 1 and CD45 double-positive cells in the lung tissue of rats exposed to scald burn injury, suggesting that leukocytes were a dominant source of calpain. Furthermore, this change was blocked by MDL28170. Finally, MDL28170 given at 1 h post-scald burn injury significantly ameliorated the wet/dry weight ratio compared with burn injury alone. Conclusions:Calpain, a product of infiltrating leukocytes, is a mediator of scald burn-induced acute lung injury that involves enhancement of inflammation and proteolysis of membrane skeleton proteins. Its late effects warrant further study.
| S-EPMC6174571 | biostudies-literature
Project description:Calpain is an intracellular Ca(2+)-regulated protease system whose substrates include proteins involved in proliferation, survival, migration, invasion, and sensitivity to therapeutic drugs. Genetic disruption of calpain attenuated the tumorigenic potential of breast cancer cells and hypersensitized cells to 17AAG, an inhibitor of the molecular chaperone HSP90. Calpain-1 or -2 overexpression rendered cells resistant to 17AAG, whereas downregulation or inhibition of calpain-1/2 led to increased cell death in multiple breast cancer cell lines, including models of HER2(+) (SKBR3) and triple-negative basal-cell-like (MDA-MB-231) breast cancer. In an MDA-MB-231 orthotopic xenograft model, calpain knockdown or 17AAG treatment independently attenuated tumor growth and metastasis, while the combination was most effective. Calpain knockdown was associated with increased 17AAG-induced degradation of the HSP90 clients cyclin D1 and AKT and multidrug resistance protein 2, which correlated with increased expression of antimitogenic p27(KIP1) and proapoptotic BIM proteins. Like other therapeutics, 17AAG can be effluxed by specific ABC transporters. Calpain expression positively correlated with the expression of P glycoprotein in mouse embryonic fibroblasts. Importantly, we show that calpain affects ABC transporter function and efflux of clinically relevant doxorubicin. These observations provide a compelling rationale for exploring the combination of calpain inhibition with new or existing cancer therapeutics.
| S-EPMC4946432 | biostudies-literature
Project description:Calpain proteases drive intracellular signal transduction via specific proteolysis of multiple substrates upon Ca(2+)-induced activation. Recently, dUTPase, an enzyme essential to maintain genomic integrity, was identified as a physiological calpain substrate in Drosophila cells. Here we investigate the potential structural/functional significance of calpain-activated proteolysis of human dUTPase.Limited proteolysis of human dUTPase by mammalian m-calpain was investigated in the presence and absence of cognate ligands of either calpain or dUTPase. Significant proteolysis was observed only in the presence of Ca(II) ions, inducing calpain action. The presence or absence of the dUTP-analogue ?,?-imido-dUTP did not show any effect on Ca(2+)-calpain-induced cleavage of human dUTPase. The catalytic rate constant of dUTPase was unaffected by calpain cleavage. Gel electrophoretic analysis showed that Ca(2+)-calpain-induced cleavage of human dUTPase resulted in several distinctly observable dUTPase fragments. Mass spectrometric identification of the calpain-cleaved fragments identified three calpain cleavage sites (between residues (4)SE(5); (7)TP(8); and (31)LS(32)). The cleavage between the (31)LS(32) peptide bond specifically removes the flexible N-terminal nuclear localization signal, indispensable for cognate localization.Results argue for a mechanism where Ca(2+)-calpain may regulate nuclear availability and degradation of dUTPase.
| S-EPMC3098232 | biostudies-literature
Project description:Aim: To understand the role of DEK1 in Arabidopsis development. Background: DEK1 has an essential role during embryogenesis and is involved in the maintenance of the epidermis. Tissues: Comparison of wild-type and ADEK1 calpain-overexpressing line. 9 samples were used in this experiment.
2009-12-09 | E-GEOD-19268 | biostudies-arrayexpress
Project description:AimsThe present study was to investigate the role of calpain in reactive oxygen species (ROS) production in endothelial cells and endothelium-dependent vascular dysfunction under experimental conditions of diabetes.Methods and resultsExposure to high glucose activated calpain, induced apoptosis and reduced nitric oxide (NO) production without changing eNOS protein expression, its phosphorylation and dimers formation in primary human umbilical vein endothelial cells (HUVECs). These effects of high glucose correlated with intracellular ROS production and mitochondrial superoxide generation. Selectively scavenging mitochondrial superoxide increased NO production in high glucose-stimulated HUVECs. Inhibition of calpain using over-expression of calpastatin or pharmacological calpain inhibitor prevented high glucose-induced ROS production, mitochondrial superoxide generation and apoptosis, which were concurrent with an elevation of NO production in HUVECs. In mouse models of streptozotocin-induced type-1 diabetes and OVE26 type-1 diabetic mice, calpain activation correlated with an increase in ROS production and peroxynitrite formation in aortas. Transgenic over-expression of calpastatin reduced ROS production and peroxynitrite formation in diabetic mice. In parallel, diabetes-induced reduction of endothelium-dependent relaxation in aortic ring was reversed by over-expression of calpastatin in mouse models of diabetes. However, the protective effect of calpastatin on endothelium-dependent relaxation was abrogated by eNOS deletion in diabetic mice.ConclusionsThis study suggests that calpain may play a role in vascular endothelial cell ROS production and endothelium-dependent dysfunction in diabetes. Thus, calpain may be an important therapeutic target to overcome diabetes-induced vascular dysfunction.
| S-EPMC4045988 | biostudies-literature
Project description:Hypertrophic scars, the most common complication of burn injuries, are characterized by excessive deposition of fibroblast-derived extracellular matrix proteins. Calpain, a calcium-dependent protease, is involved in the fibroblast proliferation and extracellular matrix production observed in certain fibrotic diseases. However, its role in the formation of post-burn hypertrophic skin scars remains largely unknown. Here, calpain expression and activity were assessed in skin fibroblasts obtained directly from patients with third-degree burns, who consequently developed post-burn hypertrophic scars. Furthermore, the antifibrotic effect of calpastatin, an endogenous calpain inhibitor, was evaluated in human fibroblasts and a murine burn model. The activity, mRNA levels, and protein levels of calpain were markedly higher in fibroblasts from the burn wounds of patients than in normal cells. Selective calpain inhibition by calpastatin markedly reduced not only the proliferation of burn-wound fibroblasts but also the mRNA and protein expression of calpain, transforming growth factor-beta 1, α-smooth muscle actin, type I and type III collagens, fibronectin, and vimentin in burn-wound fibroblasts. The anti-scarring effects of calpastatin were validated using a murine burn model by molecular, histological, and visual analyses. This study demonstrates the pathological role of calpain and the antifibrotic effect of calpastatin via calpain inhibition in post-burn hypertrophic scar formation.
| S-EPMC8199077 | biostudies-literature