Calpain activity in plasma of patients with essential tremor and Parkinson's disease: a pilot study.

Background: Essential tremor (ET) and Parkinson's disease (PD) are the two most common movement disorders in adults with similar clinical symptoms, which is hinting towards existence of coincident pathogenesis steps.Objectives: The objective of this report is to characterize the relationship between ET and PD severity and the activity of calcium-dependent proteases calpain in plasma.Methods: The study enrolled 12 volunteers for each condition: ET, PD, healthy. We evaluated the stage of PD on the H&Y scale in patients with PD, and the severity of tremor in patients with ET on the FTMS scale. IL-1ß, TNFα, IL6, IL10 were determined in plasma using ELISA. Calpain activity was measured using fluorescent substrate and zymography methods.Results: We demonstrated that the activity of calpains in plasma of patients with PD and ET increased 5.1 and 4.3 times, respectively. The increase of calpain activity in plasma of PD patients correlated with the content of IL-1ß, for ET such a connection was not found. At the advanced stages of PD calpain activity in plasma was significantly higher than that of the PD group at the early stage, and this increase was mediated by the increase in m-calpain activity. The increase in the tremor severity in ET did not lead to an increase in the activity of calpains in plasma.Conclusions: We observed general increase in the activity of calpains in plasma of both PD and ET patients that hints towards presence of the common steps in the pathogenesis of these diseases.

Platelet-derived calpain cleaves the endothelial protease-activated receptor 1 to induce vascular inflammation in diabetes.

Diabetes mellitus is a major risk factor for cardiovascular disease. Platelets from diabetic patients are hyperreactive and release microparticles that carry activated cysteine proteases or calpains. Whether platelet-derived calpains contribute to the development of vascular complications in diabetes is unknown. Here we report that platelet-derived calpain1 (CAPN1) cleaves the protease-activated receptor 1 (PAR-1) on the surface of endothelial cells, which then initiates a signaling cascade that includes the activation of the tumor necrosis factor (TNF)-α converting enzyme (TACE). The latter elicits the shedding of the endothelial protein C receptor and the generation of TNF-α, which in turn, induces intracellular adhesion molecule (ICAM)-1 expression to promote monocyte adhesion. All of the effects of CAPN1 were mimicked by platelet-derived microparticles from diabetic patients or from wild-type mice but not from CAPN1-/- mice, and were not observed in PAR-1-deficient endothelial cells. Importantly, aortae from diabetic mice expressed less PAR-1 but more ICAM-1 than non-diabetic mice, effects that were prevented by treating diabetic mice with a calpain inhibitor as well as by the platelet specific deletion of CAPN1. Thus, platelet-derived CAPN1 contributes to the initiation of the sterile vascular inflammation associated with diabetes via the cleavage of PAR-1 and the release of TNF-α from the endothelial cell surface.

Increased serum calpain activity is associated with HMGB1 levels in systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) or scleroderma is an intractable autoimmune disorder that affects multiple organs. The objectives were to investigate clinical correlations of serum calpain activity and high mobility group box 1 (HMGB1) levels with immunological and clinical traits. METHODS: A total of 31 patients with SSc, 20 age- and gender-matched healthy control subjects (HC), and 10 patients with other connective tissue diseases (CTD) were recruited in the study. We measured serum calpain activity and HMGB1 levels and analyzed the datasets (GSE40839, GSE48149, GSE76808, GSE81292, GSE33463, and GSE58095) from Gene Expression Omnibus (GEO) database to explore the potential mechanism by which calpain exerts its function through bioinformatics methods. RESULTS: Serum calpain activity was significantly increased in patients with SSc compared with those in HC and in patients with CTD and was correlated with serum HMGB1 levels, modified Rodnan skin score, erythrocyte sedimentation rate, mean platelet volume, and plateletcrit. Notably, serum calpain activity and HMGB1 levels in SSc patients with interstitial lung disease (ILD) were significantly higher than those in SSc patients without ILD. Serum calpain activity and HMGB1 levels could be the independent risk factors for SSc-ILD and novel biomarkers in patients with SSc. CONCLUSION: This is the first study that reports increased serum calpain activity and the correlation between calpain and HMGB1 in patients with SSc or SSc-ILD. The serum calpain activity and HMGB1 levels may serve as measures of ILD in patients with SSc. Also, calpain and HMGB1 could be potential therapeutic targets for patients with SSc or SSc-ILD in the future.

Cytokine/chemokine dysregulation in progressive MS patient is apparent and can be modulated by calpain inhibition.

This study examines the cytokine/chemokine profile of a 62-year-old African American male with progressive multiple sclerosis (MS). MRI images of the MS patient demonstrated generalized white matter involvement with multiple lesions in the periventricular area. A 42-plex Discovery Assay® (Eve Technologies) of the patient's plasma and peripheral blood mononuclear cells (PBMCs) supernatant or PBMC-derived T cell supernatant samples from two separate clinic visits revealed vastly differing cytokine/chemokine levels. In addition, certain cytokine/chemokine profiles had notable differences when compared to the larger patient group or patients' PBMCs treated with a calpain inhibitor in vitro. Interestingly, large numbers of cytokines/chemokines and growth factors in MS PBMCs are modulated by calpain inhibition, suggesting the clinical significance of these findings in designing better therapeutics against progressive MS.

Calpain cleaves phospholipid flippase ATP8A1 during apoptosis in platelets.

The asymmetric distribution of phospholipids in the plasma/organellar membranes is generated and maintained through phospholipid flippases in resting cells, but becomes disrupted in apoptotic cells and activated platelets, resulting in phosphatidylserine (PS) exposure on the cell surface. Stable PS exposure during apoptosis requires inactivation of flippases to prevent PS from being reinternalized. Here we show that flippase ATP8A1 is highly expressed in both murine and human platelets, but is not present in the plasma membrane. ATP8A1 is cleaved by the cysteine protease calpain during apoptosis, and the cleavage is prevented indirectly by caspase inhibition, involving blockage of calcium influx into platelets and subsequent calpain activation. In contrast, in platelets activated with thrombin and collagen and exposing PS, ATP8A1 remains intact. These data reveal a novel mechanism of flippase cleavage and suggest that flippase activity in intracellular membranes differs between platelets undergoing apoptosis and activation.

Trypanosoma cruzi immunoproteome: Calpain-like CAP5.5 differentially detected throughout distinct stages of human Chagas disease cardiomyopathy.

Chagas disease, caused by the protozoan Trypanosoma cruzi, affects millions of people worldwide, especially in Latin America. Approximately 30% of the cases evolve to the chronic symptomatic stage due to cardiac and/or digestive damage, generally accompanied by nervous system impairment. Given the higher frequency and severity of clinical manifestations related to cardiac tissue lesion, the goal of this study was the identification of proteins associated with the disease progression towards its cardiac form. Thus, T. cruzi bloodstream trypomastigotes proteins were submitted to immunoprecipitation using antibodies from patients with the asymptomatic or cardiac (stages B1 and C) forms of the disease and from healthy donors as control. Immunoreactive proteins were identified and quantified based on mass spectrometry analysis and shifts in the recognition profile were further evaluated. Compared to asymptomatic samples, IgG from stage C patients predominantly detected the I/6 autoantigen, whereas IgG from B1 patients resulted in higher yield of dihydrolipoamide acetyltransferase precursor, calpain cysteine peptidase, and two variants of CAP5.5. In this work, CAP5.5 recognition by serum immunoglobulin from patients with early cardiomyopathy generated a 23-fold abundance variation when compared to samples from asymptomatic patients, highlighting the participation of this protein in cardiac form progression of the disease. SIGNIFICANCE: While T. cruzi has become the major cause of infectious cardiomyopathy in Latin America, research groups have been struggling to find alternative treatment, vaccine candidates, and improved diagnostic tests. In addition, the absence of adequate biomarkers to assess cure and progression of disease is a major setback for clinical trials and patients monitoring. Therefore, our findings may contribute to a better understanding of T. cruzi pathogenesis and evaluation of suitable candidates for vaccine and diagnostic tests, besides the clinical applicability of the potential biomarkers for patient follow-up and prognosis. Finally, the identification of T. cruzi proteins recognized by IgG from healthy donors may contribute for the understanding and discovery of epitope conservation among a broad range of pathogens.

Vesicle-based secretion in schistosomes: Analysis of protein and microRNA (miRNA) content of exosome-like vesicles derived from Schistosoma mansoni.

Exosomes are small vesicles of endocytic origin, which are released into the extracellular environment and mediate a variety of physiological and pathological conditions. Here we show that Schistosoma mansoni releases exosome-like vesicles in vitro. Vesicles were purified from culture medium by sucrose gradient fractionation and fractions containing vesicles verified by western blot analyses and electron microscopy. Proteomic analyses of exosomal contents unveiled 130 schistosome proteins. Among these proteins are common exosomal markers such as heat shock proteins, energy-generating enzymes, cytoskeletal proteins, and others. In addition, the schistosome extracellular vesicles contain proteins of potential importance for host-parasite interaction, notably peptidases, signaling proteins, cell adhesion proteins (e.g., integrins) and previously described vaccine candidates, including glutathione-S-transferase (GST), tetraspanin (TSP-2) and calpain. S. mansoni exosomes also contain 143 microRNAs (miRNA), of which 25 are present at high levels, including miRNAs detected in sera of infected hosts. Quantitative PCR analysis confirmed the presence of schistosome-derived miRNAs in exosomes purified from infected mouse sera. The results provide evidence of vesicle-mediated secretion in these parasites and suggest that schistosome-derived exosomes could play important roles in host-parasite interactions and could be a useful tool in the development of vaccines and therapeutics.

Identification and Functional Validation of a Biomarker for the Diagnosis of Miltefosine Relapse during Visceral Leishmaniasis.

Miltefosine is the only orally administrable drug for the treatment of leishmaniasis. But in recent years, a decline in its efficacy points toward the emergence of resistance to this drug. Knowledge of biomarkers for miltefosine resistance may be beneficial for proper selection of treatment regimen. Splenic aspirates were collected and parasites cultured from patients relapsed after initial cure (N = 15) and successfully treated (N = 15) with miltefosine. Differential expression of genes in miltefosine-resistant strains was examined by DNA microarray and validated by real-time reverse transcription polymerase chain reaction and Western blotting. Of 669 upregulated genes, the cysteine protease-like protein of calpain family (GenBank: CBZ34784) was found to be significantly overexpressed in resistant parasite strains and only anti-calpain antibodies showed its presence in the sera of relapse patients through Western blotting. Calpain family cysteine protease-like protein can be useful as a potential biomarker of miltefosine unresponsiveness.

Calpain-1 regulates platelet function in a humanized mouse model of sickle cell disease.

One of the major contributors to sickle cell disease (SCD) pathobiology is the hemolysis of sickle red blood cells (RBCs), which release free hemoglobin and platelet agonists including adenosine 5'-diphosphate (ADP) into the plasma. While platelet activation/aggregation may promote tissue ischemia and pulmonary hypertension in SCD, modulation of sickle platelet dysfunction remains poorly understood. Calpain-1, a ubiquitous calcium-activated cysteine protease expressed in hematopoietic cells, mediates aggregation of platelets in healthy mice. We generated calpain-1 knockout Townes sickle (SSCKO) mice to investigate the role of calpain-1 in steady state and hypoxia/reoxygenation (H/R)-induced sickle platelet activation and aggregation, clot retraction, and pulmonary arterial hypertension. Using multi-electrode aggregometry, which measures platelet adhesion and aggregation in whole blood, we determined that steady state SSCKO mice exhibit significantly impaired PAR4-TRAP-stimulated platelet aggregation as compared to Townes sickle (SS) and humanized control (AA) mice. Interestingly, the H/R injury induced platelet hyperactivity in SS and SSCKO, but not AA mice, and partially rescued the aggregation defect in SSCKO mice. The PAR4-TRAP-stimulated GPIIb-IIIa (αIIbß3) integrin activation was normal in SSCKO platelets suggesting that an alternate mechanism mediates the impaired platelet aggregation in steady state SSCKO mice. Taken together, we provide the first evidence that calpain-1 regulates platelet hyperactivity in sickle mice, and may offer a viable pharmacological target to reduce platelet hyperactivity in SCD.

Abnormal activation of calpain and protein kinase Cα promotes a constitutive release of matrix metalloproteinase 9 in peripheral blood mononuclear cells from cystic fibrosis patients.

Matrix metalloproteinase 9 (MMP9) is physiologically involved in remodeling the extracellular matrix components but its abnormal release has been observed in several human pathologies. We here report that peripheral blood mononuclear cells (PBMCs), isolated from cystic fibrosis (CF) patients homozygous for F508del-cystic fibrosis transmembrane conductance regulator (CFTR), express constitutively and release at high rate MMP9 due to the alteration in their intracellular Ca(2+) homeostasis. This spontaneous and sustained MMP9 secretion may contribute to the accumulation of this protease in fluids of CF patients. Conversely, in PBMCs isolated from healthy donors, expression and secretion of MMP9 are undetectable but can be evoked, after 12 h of culture, by paracrine stimulation which also promotes an increase in [Ca(2+)]i. We also demonstrate that in both CF and control PBMCs the Ca(2+)-dependent MMP9 secretion is mediated by the concomitant activation of calpain and protein kinase Cα (PKCα), and that MMP9 expression involves extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) phosphorylation. Our results are supported by the fact that either the inhibition of Ca(2+) entry or chelation of [Ca(2+)]i as well as the inhibition of single components of the signaling pathway or the restoration of CFTR activity all promote the reduction of MMP9 secretion.

Identification of different domains of calpain and calpastatin from chicken blood and their role in post-mortem aging of meat during holding at refrigeration temperatures.

The aim of this study was to develop a simple, specific and rapid analytical method for accurate identification of calpain and calpastatin from chicken blood and muscle samples. The method is based on liquid-liquid extraction technique followed by casein Zymography detection. The target compounds were extracted from blood and meat samples by tris buffer, and purified and separated on anion exchange chromatography. It has been observed that buffer (pH 6.7) containing 50 mM tris-base appears to be excellent extractant as activity of analytes was maximum for all samples. The concentrations of µ-, m-calpain and calpastatin detected in the extracts of blood, breast and thigh samples were 0.28-0.55, 1.91-2.05 and 1.38-1.52 Unit/g, respectively. For robustness, the analytical method was applied to determine the activity of calpains (µ and m) in eighty postmortem muscle samples. It has been observed that µ-calpain activity in breast and thigh muscles declined very rapidly at 48 h and 24 h, respectively while activity of m-calpain remained stable. Shear force values were also declined with the increase of post-mortem aging showing the presence of ample tenderness of breast and thigh muscles. Finally, it is concluded that the method standardized for the detection of calpain and calpastatin has the potential to be applied to identify post-mortem aging of chicken meat samples.

Splanchnic tissues respond differently when piglets are offered a diet 30 % deficient in total sulfur amino acid for 10 days.

PURPOSE: A deficient total sulfur amino acid (TSAA) supply has been reported to differently affect the amino acid composition of tissues, but limited information is available about its effects on the morphology and metabolic properties of splanchnic tissues. METHODS: The amino acid composition, protein metabolism, glutathione concentration of the liver, proximal and distal jejunum, ileum and kidneys, and intestinal architecture were compared in 42-day-old piglets pair-fed either a diet deficient (TSAA-; 28 % deficiency) or sufficient (TSAA+) in TSAA for 10 days. RESULTS: The supply of TSAA had no effect on tissue weights, but influenced the amino acid composition in a tissue-dependent manner. Compared with animals receiving diet TSAA+, the concentrations of Met and Ser were higher in liver protein of TSAA- animals while the Cys concentration in protein was lower in the liver but higher in the distal jejunum. The TSAA supply had no effect on protein synthesis and proteolytic activities of tissues. Villus width and surface, and crypt surface were lower in the proximal jejunum of TSAA- versus TSAA+ pigs. Crypt surface in the ileum of TSAA- pigs was higher. Pigs receiving diet TSAA- had lower GSH and GSSG concentrations in the liver and proximal jejunum, but the GSH/GSSG ratio was decreased only in the liver. CONCLUSIONS: A greater nutritional priority appears to be given to splanchnic tissues so that its growth and protein metabolism can be maintained when the TSAA supply is limiting. The amino acid composition, glutathione status, and intestinal mucosa architecture are affected in a tissue-dependent manner.

Dicer cleavage by calpain determines platelet microRNA levels and function in diabetes.

RATIONALE: MicroRNAs (miRNAs) are short noncoding RNA species generated by the processing of longer precursors by the ribonucleases Drosha and Dicer. Platelets contain large amounts of miRNA that are altered by disease, in particular diabetes mellitus. OBJECTIVE: This study determined why platelet miRNA levels are attenuated in diabetic individuals and how decreased levels of the platelet-enriched miRNA, miR-223, affect platelet function. METHODS AND RESULTS: Dicer levels were altered in platelets from diabetic mice and patients, a change that could be attributed to the cleavage of the enzyme by calpain, resulting in loss of function. Diabetes mellitus in human subjects as well as in mice resulted in decreased levels of platelet miR-142, miR-143, miR-155, and miR-223. Focusing on only 1 of these miRNAs, miR-223 deletion in mice resulted in modestly enhanced platelet aggregation, the formation of large thrombi and delayed clot retraction compared with wild-type littermates. A similar dysregulation was detected in platelets from diabetic patients. Proteomic analysis of platelets from miR-223 knockout mice revealed increased levels of several proteins, including kindlin-3 and coagulation factor XIII-A. Whereas, kindlin-3 was indirectly regulated by miR-223, factor XIII was a direct target and both proteins were also altered in diabetic platelets. Treating diabetic mice with a calpain inhibitor prevented loss of platelet dicer as well as the diabetes mellitus-induced decrease in platelet miRNA levels and the upregulation of miR-223 target proteins. CONCLUSIONS: Thus, calpain inhibition may be one means of normalizing platelet miRNA processing as well as platelet function in diabetes mellitus.

Increased cerebrospinal fluid calpain activity and microparticle levels in Alzheimer's disease.

BACKGROUND: Calpain has been associated with the pathophysiology of Alzheimer's disease (AD) and with apoptotic neuronal cell death leading to microparticles (MPs) formation. METHODS: A total of 64 patients with AD and 52 age- and gender-matched cognitively healthy elderly controls were included in the study. We measured calpain activity and levels of MPs, amyloid beta (Aß1-42), h-tau, and p-tau181. RESULTS: AD patients showed significantly increased calpain activity and higher levels of MPs in cerebrospinal fluid (CSF) and significantly decreased calpain activity and lower levels of MPs in serum and plasma compared with healthy controls. Combined assessment of calpain activity and Aß1-42 levels in CSF improved diagnostic accuracy as compared with singular or combined traditional CSF biomarkers of AD. CONCLUSIONS: This is the first study showing increased calpain activity and microparticle levels in CSF of AD patients. Calpain activity could represent a novel diagnostic and prognostic biomarker and promising treatment target for AD.

Eryptosis in lead-exposed workers.

Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8µg/dl) and non-exposed workers (4.2µg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca(2+)]i and 1.6 times higher µ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (<0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca(2+)], µ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications.

Effects of physical restraint and electrical stunning on plasma corticosterone, postmortem metabolism, and quality of broiler breast muscle.

The objective of this study was to determine the effects of physical restraint and electrical stunning on plasma corticosterone, postmortem metabolism, and quality of broiler breast muscle. Before slaughter, a total of 160 Arbor Acres broilers were randomly categorized into 2 replicate pens (80 broilers per pen) and every pen was randomly divided into 4 groups (free struggle, physical restraint, free struggle and electrical stunning, and physical restraint and electrical stunning; n=20 per group). Glucose, lactate, and corticosterone were determined on blood plasma samples. Pectoralis major were removed after evisceration and used for determination of meat quality, energy metabolism, and calpain activity. In this study, reducing free struggle by physical restraint combined with electrical stunning improved (P<0.05) meat water holding capacity. Free struggle preslaughter and during bleeding increased (P<0.05) breast muscle redness, energy metabolism, and autolysis of µ/m-calpain and decreased (P<0.05) meat shear values. Physical restraint and electrical stunning decreased (P<0.05) plasma corticosterone level.

The role of intraplatelet reactive oxygen species in the regulation of platelet glycoprotein Ibα ectodomain shedding.

Glycoprotein (GP) Ibα ectodomain shedding has become a generally accepted negative regulatory mechanism of platelet function. Stimulation of platelet with either physiological or chemical compound results in GPIbα ectodomain shedding in vitro and in vivo, the mechanism, however, is not totally understood. Here we show, collagen, thrombin, and calcium ionophore A23187 induce reactive oxygen species (ROS) generation, and simultaneously incur GPIbα ectodomain shedding. ROS scavengers N-acetylcysteine (NAC) and dithiothreitol (DTT) abolish not only collagen, thrombin, and A23187 induced ROS production, but also GPIbα ectodomain shedding. Interestingly, a recognized calpain activator, dibucaine, induces both ROS production and GPIbα shedding, which are also obviously reduced by NAC and DTT. Furthermore, calpain inhibitors calpain inhibitor I and carbobenzoxy-valinyl-phenylalaninal, obviously reduce dibucaine, thrombin, and A23187-induced ROS generation. These data indicate that ROS plays a key role in collagen, thrombin, and A23187-induced GPIbα ectodomain shedding. Calpain is an up-stream regulator that regulates ROS-mediated GPIbα shedding.

Genetic polymorphism of the CAPN1 gene is associated with meat quality traits in Japanese quail.

1. The objective of the study was to investigate the polymorphisms in two regions of the calpain 1 (CAPN1) gene and their association with breast and thigh meat quality in Japanese quail (ultimate pH (pHu), lightness, redness, yellowness, drip loss, thawing-cooking loss, water holding capacity and shear force, SF). 2. Blood samples were collected randomly from 100 birds and DNA was extracted using a commercial kit. Genotypes were determined by PCR amplification followed by single-strand conformation polymorphism (SSCP) analysis. The effect of CAPN1 genotypes on meat quality traits were analysed using a general linear model (GLM) procedure. 3. Genotypes of the CAPN1 gene in the first region (217-bp) analysed were significantly associated with yellowness and SF. The TT genotype showed significantly higher yellowness and lower shear force (more tenderness) than CT and CC genotypes. Genotypes of the second region of the gene (intron 4, 800-bp) were significantly associated with pHu, redness and SF of the breast meat. The BB genotype showed significantly lower pHu and redness and higher SF (lower tenderness) than other genotypes. 4. Information on polymorphisms of the CAPN1 gene will eventually provide useful information for improving meat quality of Japanese quail through marker-assisted selection.