Biomedical subjects

Evgeny A Minin

Publications and source records attributed to Evgeny A Minin.

5 recordsLinked to original sources

PubMed2006

Nitric oxide synthase is up-regulated in muscle fibers in muscular dystrophy.

Nitric oxide (NO) mediates fundamental physiological actions on skeletal muscle. The neuronal NO synthase isoform (NOS1) was reported to be located exclusively in the sarcolemma. Its loss from the sarcolemma was associated with development of Duchenne muscular dystrophy (DMD). However, new studies evidence that all three NOS isoforms-NOS1, NOS2, and NOS3-are co-expressed in the sarcoplasm both in normal and in DMD skeletal muscles. To address this controversy, we assayed NOS expression in DMD myofibers in situ cytophotometrically and found NOS expression in DMD myofibers up-regulated. These results support the hypothesis that NO deficiency with consequent muscle degeneration in DMD results from NO scavenging by superoxides rather than from reduced NOS expression.

Biopsy↗

PubMed2006

Nitric oxide synthase in muscular dystrophies: a re-evaluation.

Duchenne and Becker muscular dystrophies (DMD and BMD) are associated with decreased total nitric oxide (NO). However, mechanisms leading to NO deficiency with consequent muscle-cell degeneration remain unknown. To address this issue, we examined skeletal muscles of DMD and BMD patients for co-expression of NO synthase (NOS) with nitrotyrosine and transcription factor CREB, as well as with enzymes engaged in NO signaling. Employing immunocytochemical labeling, Western blotting and RT-PCR, we found that, in contrast to the most commonly accepted view, neuronal NOS was not restricted to the sarcolemma and that muscles of DMD and BMD patients retained all three NOS isoforms with an up-regulation of the inducible NOS isoform, CREB and nitrotyrosine. We suggest that enhanced nitrotyrosine immunostaining in muscle fibers as well as in the vasculature of DMD and BMD specimens reflects massive oxidative stress, resulting in withdrawal of NO from its regular physiological course via the scavenging actions of superoxides.

3',5'-Cyclic-GMP Phosphodiesterases↗

PubMed2005

L-Arginine-NO-cGMP signaling following acute liver injury in the rat.

The incidence of liver diseases has increased over the past few years. For this reason, the consequences of induced nitric oxide (NO) synthesis in liver damages warrant further studies. To address this issue, we investigated the expression of key enzymes engaged in the control of NO signaling in the rat liver after carbon tetrachloride (CCl4) intoxication and subsequent regeneration. CCl4 intoxication resulted in up-regulation of the entire NO signal transduction machinery. Expression patterns of arginase, soluble guanylyl cyclase and cyclic nucleotide phosphodiesterase revealed striking parallels with that of NO synthase (NOS). Co-expression of the major components of the l-arginine-NO-cGMP signaling cascade both in hepatocytes and in nonparenchymal cells indicates an autocrine rather than a paracrine fashion of NO signaling in the liver. Up-regulation of NOS after CCl4 intoxication fell behind the oxidative stress and was found to be associated with the initiation of parenchymal regeneration implying a beneficial effect of NO.

Animals↗

PubMed2005

Compartmentalization of NO signaling cascade in skeletal muscles.

Skeletal muscle functions regulated by NO are now firmly established. However, the literature on the compartmentalization of NO signaling in myocytes is highly controversial. To address this issue, we examined localization of enzymes engaged in L-arginine-NO-cGMP signaling in the rat quadriceps muscle. Employing immunocytochemical labeling complemented with tyramide signal amplification and electron microscopy, we found NO synthase expressed not only in the sarcolemma, but also along contractile fibers, in the sarcoplasmic reticulum and mitochondria. The expression pattern of NO synthase in myocytes showed striking parallels with the enzymes engaged in L-arginine-NO-cGMP signaling (arginase, phosphodiesterase, and soluble guanylyl cyclase). Our findings are indicative of an autocrine fashion of NO signaling in skeletal muscles at both cellular and subcellular levels, and challenge the notion that the NO generation is restricted to the sarcolemma.

Animals↗

PubMed2005

A multicolor fluorescence immunostaining technique for simultaneous antigen targeting.

A general problem in immunocytochemistry is the development of a reliable multiple immunolabeling method with primary antibodies originating from the same host species. Here, we briefly outline different approaches intended to close this technological gap and focus on multiple immunolabeling with monoclonal primary antibodies. To this end, we generated a basic universal protocol for the use of secondary antibodies selectively recognizing different isotypes/subclasses of monoclonal primary antibodies. This approach is widely applicable and offers a simple procedure for simultaneously detecting two or more antigens.

Animals↗