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The chemical analysis of muscle biopsies from patients with Duchenne muscular dystrophy has revealed several abnormalities of calcium regulation. The calcium content of the muscle cells is elevated and the sarcoplasmic reticulum is less able to regulate the calcium within the cell. Furthermore, two calcium-binding proteins, including calsequestrin, were found to be abnormally low in Duchenne dystrophic muscle cells. To further investigate the abnormalities of calcium regulation in these cells, investigators have examined both the calcium-sensitive protein calmodulin and the calmodulin-dependent enzyme, calcium-ATPase. It was found that calmodulin is elevated in the muscle cells of Duchenne dystrophy patients, and the elevation is greater in early stages of the disease and in patients whose disease is progressing more slowly. Indeed, the calmodulin content in cases of advanced disease is within the normal range. Calcium-ATPase activity was reduced in the Duchenne muscle cells; the addition of more calmodulin in the laboratory did not succeed in raising the activity of this enzyme. The results indicate that abnormalities in calcium regulation are among the first changes to occur in the progression of Duchenne muscular dystrophy. The authors suggest that these abnormalities are involved in the progression of the disease. (Consumer Summary produced by Reliance Medical Information, Inc.)

Deficit of lamin A/C or emerin causes genetically transmitted Emery-Dreifuss muscular dystrophy (EDMD). As lamins are considered to be mediators of oxidative stress, the antioxidant/oxidant status was examined. The total oxidant/antioxidant status in serum was examined in 29 cases of Emery-Dreifuss muscular dystrophy. The study included 12 autosomal-dominant laminopathies (AD-EDMD), 17 X-linked emerinopathies (X-EDMD) and 20 age-matched normal subjects. Total oxidant status (TOS) was reduced in all cases, and the total antioxidant capacity (TAC) was found to be decreased in the majority of the patients (in 82.8%). A relationship between TOS level and disease progression was noted. No correlation between TOS/TAC level and cardiological or neurological parameters was detected. The results of the study indicate disturbances of redox balance in EDMD patients. Determination of TOS/TAC might help to assess the progress of the disease and the potential effectiveness of antioxidant therapy.

Tenascin-C (TN-C), a hexameric extracellular matrix glycoprotein, is a pleiotropic regulator of a variety of cell functions associated with embryogenesis, wound healing, cell proliferation, differentiation, motility, and nerve regeneration. Due to its role in remodeling processes, TN-C is involved with many pathologic states including cardiac and vascular diseases as well as inflammation and cancer. Assessment of circulating TN-C may help with identification of heart disease, especially in conjunction other cardiac biomarkers. It may be considered a specific biomarker useful in detecting cardiac pathology, especially in early disease stages and subsequent monitoring of cardiologic therapy. This review will highlight the biochemistry and usefulness of TN-C in clinical laboratory diagnostics to date., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Tenascin-C (TN-C), an extracellular matrix glycoprotein, is of diagnostic and prognostic value in different heart diseases. One such dilated cardiomyopathy (DCM) with conduction disturbances is one of the most serious manifestations in Emery-Dreifuss muscular dystrophy (EDMD). Herein we therefore detail work to evaluate the potential significance of circulating TN-C in patients with EDMD, speculating that it may define the cardiac dysfunction, especially in patients who may be cardiac asymptomatic, but still be at risk of sudden death., Material and Method: Serum levels of TN-C were quantified by sandwich immunoassay ELISA in 25 EDMD patients (10 with laminopathy-AD-EDMD and 15 with emerinopathy-X-EDMD), 8 X-EDMD carriers, 9 disease controls (patients with dystrophinopathy), and 15 age-matched healthy controls. Fourteen of the EDMD patients had repeated TN-C examinations after 3 to 7 years., Results: The levels of circulating TN-C were elevated in AD-EDMD and X-EDMD patients, as well as in some X-EDMD carriers, and patients with dystrophinopathy. The correlation between the TN-C level and left end-systolic ventricle diameter (LVDD) was significant in X-EDMD, while those with left atrium diameter (LAD) and the ejection fraction (EF) were not. In "follow-up" studies TN-C levels were not found to change over time in AD-EDMD, while rising in X-EDMD., Conclusions: The presented results indicate that assessments of circulating TN-C levels may help to identify EDMD patients at risk of dilated cardiomyopathy. TN-C might therefore be considered a candidate for a new biomarker, useful in detecting of cardiomyopathy and in further monitoring of the DCM therapy in patients with EDMD., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases, which are present in central and peripheral nervous system. They are considered to be involved in the pathogenesis of several neurological diseases, as multiple sclerosis, Alzheimer disease, and amyotrophic lateral sclerosis (ALS). The aim of the present study was to evaluate the application of the pattern recognition methods for the assessment of MMPs in serum of patients with ALS. Thirty patients with amyotrophic lateral sclerosis (ALS), in two subgroups: (i) with mild and (ii) severe progressing ALS, and 15 control healthy subjects were studied. The metalloproteinases MT-MMP-1, MMP-2, MMP-9 were examined. Additional variables (age of subjects and disease duration) were also analyzed by using a standard, parallel and hierarchical classifiers. Our results indicate that: (i) MMP-2 in serum may be an important marker for the evaluation of ALS progress; (ii) the set of two features {MT-MMP-1, MMP-9} may be helpful in differentiation between ALS and healthy subjects; (iii) the error rates obtained for the pair-wise linear classifier were similar to those received for the classifiers (standard, parallel, and hierarchical) based on k-NN rule. We conclude that the pattern recognition methods may be useful for the evaluation of significance MMPs as markers in neurodegenerative diseases, such as ALS.

In the pathogenesis of dilated cardiomyopathy (DCM) in Emery-Dreifuss muscular dystrophy (EDMD) matrix metalloproteinases (MMPs) are supposed to be involved and may have diagnostic/prognostic value. Serum levels of MT1-MMP, MMP-2 and MMP-9 were quantified by ELISA and zymography in 22 EDMD patients and 15 age-matched controls. In the autosomal-dominant EDMD MMP-2 and MT1-MMP were increased in all cases, and MMP-9 was increased in two of the eight examined patients. In the X-linked EDMD MMP-2 expression was increased in all the cases, MMP-9 level was elevated in 3 of the 14 cases, and MT1-MMP was decreased in eight of these patients. There was no evident correlation between the MMPs level and the different cardiac parameters including left-ventricular end-diastolic diameter, left atrial diameter and left ventricular ejection fraction in either form of EDMD. The presented results indicate that a changed level of matrix metalloproteinases, especially that of MMP-2 in serum, may be of value for detection of cardiac involvement in EDMD patients, especially in those patients with no evident subjective cardiac symptoms. Further follow-up studies of MMPs are needed to check if their determination is of value for monitoring of the progression of atrial/ventricular dilatation. MMPs determinations may also be useful for monitoring DCM treatment by synthetic MMPs inhibitors.

The pathogenesis of dilated cardiomyopathy in Emery- Dreifuss muscular dystrophy (EDMD) is still unknown. Autoimmune mechanisms have recently been taken into account. The aim of this investigation was to determine whether the level of circulating antibodies to heart proteins which were previously detected, correlates with disease progression. Troponin I was chosen as the target. Ten patients with EDMD and 10 age-matched normal controls were tested. An enzyme linked immunoassay (ELISA) technique was used to determine the possible relation between the level of anti-troponin I antibodies at diagnosis and at followup. Autoantibodies against troponin I were detected in all EDMD patients. At diagnosis the level was higher in the X-linked EDMD form (X-EDMD), as compared to the autosomal dominant form (AD-EDMD). At follow-up the elevated level of the autoantibodies persisted in all the EDMD cases. However, in the AD-EDMD form, the level was found to be significantly rising with disease progression, in the X-EDMD form, on the other hand, it was declining. No clear-cut relationship between the level of the circulating antibodies and cardiac symptomatology was present. Detection of anti-troponin I antibodies may provide a non-invasive marker of early stages of dilated cardiomyopathy in EDMD.

We present the results of biochemical and electron microscopic (EM) examinations of the spinal cord myelin from SOD1G93A transgenic Sprague Dawley rats in the early and late symptom-free period of the disease (60 and 93 days of life) and after four-leg paralysis has occurred (120 days of life). Biochemical and ultrastructural changes of myelin started already in the symptom-free period and become most pronounced in the paralyzed animals. Biochemical examinations indicated a decrease of lipids, phospholipids, cholesterol and cerebrosides. The pattern of particular phospholipids was in the normal range. A progressive decrease of the percentages of proteolipid, DM-20 and Wolfgram proteins was evident. Myelin basic proteins I and II were less affected. In EM,massive myelin disorganization was observed.

Dilated cardiomyopathy is one of the leading abnormalities in Emery-Dreifuss Muscular Dystrophy (EDMD). The pathogenesis of heart involvement in EDMD is, however, unknown. Autoimmune mechanisms have also to be taken into account. The aim of this study was to search for the presence of anti-heart antibodies in EDMD patients. The anti-heart auto-antibodies were detected in serum of 14 EDMD patients (the X-linked and the AD-Autosomal Dominant form). The control groups comprised 10 patients with Dilated Cardiomyopathy (DCM) and 10 healthy subjects. To screen serum for anti-heart antibodies against ventricular muscle proteins, they were separated by polyacrylamide gel electrophoresis, followed by Western blotting. In EDMD and DCM, IgG anti-heart antibodies against heart ventricular proteins were detected. In both diseases, 85 kD protein appeared to be the most immunogenic. Anti-troponin I (24 kD), anti-tropomyosin (35 kD) and anti-actin (43 kD) reactivity was less intense. There were significant differences in the reactivity of auto-antibodies between both EDMD forms, and also between EDMD and the DCM patients. No clear-cut correlation between the reactivity and frequency of the antibodies and clinical parameters of the EDMD patients was detected. The anti-heart proteins are reliable markers of immune involvement in dilated cardiomyopathy in the course of EDMD. Short- and long-term follow-up may define the role of anti-heart antibodies in predicting the susceptibility at risk of dilated cardiomyopathy in EDMD patients.

Aetiology and pathogenesis of amyotrophic lateral sclerosis (ALS) is still a mystery. Among several hypotheses autoimmune mechanisms are also taken into account. We report here our investigations of auto-antibodies against proteins of spinal cord cells in the cerebrospinal fluid (CSF) and serum of ALS patients. The results were correlated with the severity of disease course. The subjects were 57 ALS patients (29 severe, 28 mild) and 10 normal controls. The major finding in CSF was the presence of antibodies against a 70 kD protein in the majority of ALS patients. This protein was identified as neurofilament 68. The second protein of high reactivity and frequency of appearance was a 82 kD protein, which was identified as a-actinin. Less reactive and less frequent were antibodies directed against 55 kD and 40 kD proteins. They were immunologically defined to be related to desmin and actin, resp. The difference between the reactivity of anti-neurofilament and anti-desmin related protein in the severe and mild ALS groups was significant. More frequent were the anti-neurofilament antibodies in the severe ALS cases as compared to the milder ones. In normal CSF, antibodies directed against 55 kD, 70 kD and 82 kD proteins were present in traces and appeared in 5%, 20% and 10% of cases, respectively. In the serum of 30% of severe ALS patients traces of antibodies against 70 kD protein were detected. The morphological studies in the presence of CSF of ALS patients revealed pronounced immunoreactivity of spinal cord neurons, mainly within anterior horns. The significance of the presence of auto-antibodies in CSF of ALS patients against cellular proteins of the spinal cord is hard to define. It is conceivable that they appear as a secondary immunological consequence of neuronal death. It is also possible that they may accelerate the course of neuronal degeneration.

Emerin and lamins are nuclear proteins, which are missing or defective in Emery-Dreifuss muscular dystrophy (EDMD). The aim of this study was to test the expression of these proteins in skeletal muscles in the X-linked (X-EDMD) and autosomal dominant (AD-EDMD) form. The study group consisted of 11 patients with X-EDMD, 11 patients of the AD-EDMD and 20 age-matched normal subjects. Expression of emerin and lamins in muscles were analyzed by Western blotting and the immunocytochemical technique. Using the Western blotting procedure emerin was detected in traces in the X-linked form. In the majority of these cases (6/11) it was connected with a decreased concentration of lamin A, in four patients a lowered concentration of lamin C was present. Lamin B2 was either normal (8/11), or decreased (3/11). Deficit of lamin A was a characteristic feature for AD-EDMD in the majority of these cases (9/11), while in two of these patients a decrease of lamin C, in four cases a lowered level of emerin was also present. In one AD-EDMD patient of a decrease of lamin C, but normal lamin A was present. Following the immunocytochemical examination the decrease of lamin A/C in X-EDMD and of emerin in AD-EDMD was also observed. The above mentioned data demonstrated that in X-EDMD and AD-EDMD the deficit of the appropriate proteins is not restricted either to emerin or lamins. The defect is more widespread and results in disruption of several nuclear proteins. This study also indicated that for the diagnostic EDMD purposes the immunocytochemical detection of emerin/lamins has to be accomplished by quantitative immunochemical analyses of the above mentioned proteins.

Dystrophin, a product of a gene located at the chromosome Xp21 locus, is a cytoskeletal protein expressed in skeletal, cardiac and smooth muscles, and in the brain, and is located on the inner site of the plasma membrane. Dystrophin in the skeletal muscles is absent or appears only in traces in Duchenne dystrophy, it is reduced with normal/changed molecular weight in Becker dystrophy and it is absent/reduced in mdx mice. It is supposed that dystrophin acts either as a structural scaffold that supports mechanical stress in sarcolemma, or participates in regulating intracellular Ca2+ level. There are also data indicating that dystrophin takes part in force and signal transduction processes, in the aggregation of neurotransmitter receptors, and prevents an excessive generation of reactive oxygen free radical species. The main hypotheses indicate that lack of structural support, an excessive influx of Ca2+ ions into the muscle cell, or a combination of both these mechanisms in dystrophin-deficient muscle fibres, is responsible for muscle pathology in progressive muscular dystrophy. There are arguments supporting these hypotheses. There are, however, also data indicating that the presented arguments are doubtful. Despite recent advances in the knowledge of the pathogenesis of muscular dystrophies and the advent of modern techniques, we are still very far away from understanding what is the real function of dystrophin in muscle.

One of the hypotheses in amyotrophic lateral sclerosis (ALS) indicates on excitatory amino acids as the cause of neuronal death. Changes in their concentration in the tissues and body fluids may be the consequence of a defect in their transport, as well as abnormal activities of glutamate metabolizing enzymes. Abnormal synthesis/degradation of these enzymes and/or influence of activators/inhibitors should be taken into account. The activity of enzymes of glutamate metabolism of rat spinal cord in vitro in the presence of serum and cerebrospinal fluid (CSF) of 20 patients with ALS and 20 healthy controls was tested. In the presence of serum of the ALS patients glutaminase was significantly stimulated, instead of being inhibited; the inhibition of GABA aminotransferase, glutamate decaboxylase and aspartate aminotransferase was less evident than in the controls, glutamate dehydrogenase lost its activity more than in control conditions, the inhibition of glutamine synthetase was comparable to that when normal serum was applied. The activity of the enzymes in the presence of CSF of ALS patients was generally similar to that of normal CSF, except of glutaminase which was stimulated and GABA aminotransferase, which was inhibited stronger than in the presence of normal CSF. This study indicates, that changes in glutamate concentration in tissues and body fluids in ALS may be caused, at least partly, by abnormalities in the activity of glutamate metabolism enzymes, which are in turn induced by neurotoxic agents present in body fluids of ALS patients.

Glycoproteins in cerebrospinal fluid of 55 patients with amyotrophic lateral sclerosis (ALS), six disease controls (multifocal motor neuropathy, sensorimotor neuropathy, Guillain-Barré syndrome, spinal muscular atrophy type II, motor neuropathy with monoclonal gammopathy) and 20 healthy controls were separated by PAGE electrophoresis and then detected immunochemically with peanut agglutinin (PNA). In 36 amyotrophic lateral sclerosis patients the 262 kDa glycoprotein was significantly increased (over the normal mean +/- SD x 2), which was associated with a decrease in the 114 kDa fraction. In the remaining patients, both fractions were either equal in concentration or the 114 kDa glycoprotein predominated. In normal cerebrospinal fluid, the 114 kDa glycoprotein predominated over the other glycoproteins. The total amount of separated glycoproteins was increased in 15 amyotrophic lateral sclerosis patients. In 12 of them it was followed by an increase in the percentage of the 262 kDa glycoprotein. There was no correlation between the content of the peanut agglutinin-labelled glycoproteins and the patients' age, duration and severity of the disease. There was a correlation between the 262 kDa glycoprotein being increased in cerebrospinal fluid and the electrophysiological pattern of denervation seen in electromyographic study. The glycoproteins change, similar to that occurring in amyotrophic lateral sclerosis patients, was also observed in one case of multifocal motor neuropathy (MMN). We suggest that in amyotrophic lateral sclerosis and multifocal motor neuropathy, the peanut agglutinin-labelled glycoproteins are released in excess from the nervous tissues into the cerebrospinal fluid as a result of neuronal degeneration. The question to be answered is, whether the released glycoproteins are becoming targets for auto-antibodies.

Glycoconjugates in the serum of 73 patients with amyotrophic lateral sclerosis (ALS), 21 cases of other motor neuron diseases and 20 healthy controls were determined. Cerebrospinal fluid (CSF) was studied in 64, 7 and 10 of these subjects, respectively. The level of sialic acid containing glycoconjugates, detected by Maakia amurensis agglutinin (MAA), was decreased in the serum of 61.6% of the ALS patients, while in the CSF it was decreased, on average, in 75% of these cases. Only in single ALS cases was the concentration of these glycoconjugates increased. There was no correlation between the content of MAA-labelled glycoconjugates both in serum and CSF and the titre of sialic acid containing anti-GM1 gangliosides. The glycoconjugates, detected by peanut agglutinin (PNA) which recognizes the disaccharide galactose beta(1-3)N- acetylgalactosamine (GGN), were decreased in the serum of 78.1% of ALS patients, while in CSF they were increased in 54.7% of these cases. There was no correlation between the concentration of PNA-labelled glycoconjugates both in serum and CSF as well as the titre of antibodies against GGN-containing anti-GM1 and anti- AGM1 gangliosides. Changes in the level of the MAA- and PNA- labelled glycoconjugates, as well as the titre of anti-GM1 and anti-AGM1 gangliosides antibodies were not specific for ALS. They were also observed in some cases of other motor neuron diseases. The low level of the lectin-labelled glycoconjugates in serum and partly in CSF of the majority of ALS patients is possibly the consequence of their accelerated clearance and/or specific inactivation by the formation of immune complexes or epitope binding. Degeneration of neurons and muscle cells could also be responsible. The relatively low incidence of high anti- glycolipids antibodies titre may be, at least partly, connected with the low concentration of the appropriate antigens. The increased content of PNA-labelled glycoconjugates in the CSF of the majority of ALS patients, together with the low incidence of high titre of antibodies against the appropriate glycolipids, could indicate that in CSF this lectin binds to the GGN epitope of glycoproteins rather than to the GGN epitope of glycolipids., (Copyright 1999 Lippincott Williams & Wilkins)