<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>The free radical nitric oxide (NO) and Ca<sup>2+</sup> are critical regulators of skeletal muscle exercise performance and fatigue. The major source of NO in skeletal muscle cells is the neuronal form of the enzyme Nitric oxide synthase (nNOS). One of the most peculiar characteristics of the Nurse cell of <italic>Trichinella spiralis</italic> (<italic>T. spiralis</italic>) is the complete loss of the contractile capabilities of its derivative striated muscle fiber. The aim of the present study was to clarify the expression of nNOS protein and mRNA in striated muscles during the muscle phase of <italic>T. spiralis</italic> infection in mice. Muscle tissue samples were collected from mice at days 0, 14, 24, and 35 post infection (d.p.i.). The expression of nNOS was investigated by immunohistochemistry, and the expression levels of mRNA of mouse Nitric oxide synthase 1 (<italic>Nos1)</italic> by real-time PCR. The presence of nNOS protein was still well observable in the disintegrated sarcoplasm at the early stage of infection. The cytoplasm of the developing and mature Nurse cell showed the absence of this protein. At least at the beginning of the Nurse cell development, <italic>Trichinella</italic> uses the same repairing process of skeletal muscle cell, induced after any trauma and this corroborates very well our results concerning the nNOS expression on day 14 p.i. At a later stage, however, we could suggest that the down-regulation of nNOS in the Nurse cell of <italic>T. spiralis</italic> either serves a protective function or is an outcome of the genetic identity of the Nurse cell.</p>
</abstract>

The free radical nitric oxide (NO) and Ca2+ are critical regulators of skeletal muscle exercise performance and fatigue. The major source of NO in skeletal muscle cells is the neuronal form of the enzyme Nitric oxide synthase (nNOS). One of the most peculiar characteristics of the Nurse cell of Trichinella spiralis (T. spiralis) is the complete loss of the contractile capabilities of its derivative striated muscle fiber. The aim of the present study was to clarify the expression of nNOS protein and mRNA in striated muscles during the muscle phase of T. spiralis infection in mice. Muscle tissue samples were collected from mice at days 0, 14, 24, and 35 post infection (d.p.i.). The expression of nNOS was investigated by immunohistochemistry, and the expression levels of mRNA of mouse Nitric oxide synthase 1 (Nos1) by real-time PCR. The presence of nNOS protein was still well observable in the disintegrated sarcoplasm at the early stage of infection. The cytoplasm of the developing and mature Nurse cell showed the absence of this protein. At least at the beginning of the Nurse cell development, Trichinella uses the same repairing process of skeletal muscle cell, induced after any trauma and this corroborates very well our results concerning the nNOS expression on day 14 p.i. At a later stage, however, we could suggest that the down-regulation of nNOS in the Nurse cell of T. spiralis either serves a protective function or is an outcome of the genetic identity of the Nurse cell.

Down-regulation of neuronal form of Nitric oxide synthase in the Nurse cell of <italic>Trichinella spiralis</italic>

Department of Pathology, Faculty of Medicine

Helminthologia

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Down-regulation of neuronal form of Nitric oxide synthase in the Nurse cell of 

The free radical nitric oxide (NO) and Ca2+ are critical regulators of skeletal muscle exercise performance and fatigue. The major source of NO in skeletal...

Down-regulation of neuronal form of Nitric oxide synthase in the Nurse cell of Trichinella spiralis

Article Category: Research Article

Published Online: Apr 23, 2024

Page range: 40 - 45

Received: Aug 24, 2023

Accepted: Nov 16, 2023

DOI: https://doi.org/10.2478/helm-2024-0003

Keywords
nNOS, Nurse cell, skeletal muscle,

© 2024 R. Milcheva et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Down-regulation of neuronal form of Nitric oxide synthase in the Nurse cell of Trichinella spiralis

Article Category: Research Article

Published Online: Apr 23, 2024

Page range: 40 - 45

Received: Aug 24, 2023

Accepted: Nov 16, 2023

DOI: https://doi.org/10.2478/helm-2024-0003

KeywordsnNOS, Nurse cell, skeletal muscle,

© 2024 R. Milcheva et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
nNOS, Nurse cell, skeletal muscle,