Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells

This study was designed to examine the autophagy in sino-atrial (SA) nodal cells from the normal adult mouse heart. Autophagy is the cellular process responsible for the degradation and recycling of long-lived and/or damaged cytoplasmic components by lysosomal digestion. In the heart, autophagy is k...

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Main Authors:	Omatsu-Kanbe, Mariko, Yamamoto, Takefumi, Matsuura, Hiroshi
Format:	Online
Language:	English
Published:	Japan Society of Histochemistry and Cytochemistry 2011
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3210427/

id	pubmed-3210427
recordtype	oai_dc
spelling	pubmed-32104272011-11-17 Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells Omatsu-Kanbe, Mariko Yamamoto, Takefumi Matsuura, Hiroshi Regular Article This study was designed to examine the autophagy in sino-atrial (SA) nodal cells from the normal adult mouse heart. Autophagy is the cellular process responsible for the degradation and recycling of long-lived and/or damaged cytoplasmic components by lysosomal digestion. In the heart, autophagy is known to occur at a low level under physiological conditions, but to become upregulated when cells are exposed to certain stresses, such as ischemia. We examined whether the basal level of autophagy in SA nodal cells was different from that in ventricular or atrial myocytes. An ultrastructural analysis revealed that the SA nodal cells contained a number of autophagic vacuoles (autophagosomes) with various stages of degradation by lysosomal digestion, whereas the number of those in ventricular or atrial myocytes was either negligible or very small. The immunostaining of autophagosome marker microtubule-associated protein 1 light chain 3 (LC3) and lysosome marker lysosome-associated membrane protein 1 (LAMP1) indicated that the content of both autophagosomes and lysosomes were much greater in SA nodal cells than in ordinary cardiomyocytes. Our results provide evidence that the autophagy is active in normal SA nodal cells, which is not a stress-activated process but a constitutive event in the mouse heart. Japan Society of Histochemistry and Cytochemistry 2011-10-26 2011-08-10 /pmc/articles/PMC3210427/ /pubmed/22096262 http://dx.doi.org/10.1267/ahc.11030 Text en © 2011 The Japan Society of Histochemistry and Cytochemistry This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Omatsu-Kanbe, Mariko Yamamoto, Takefumi Matsuura, Hiroshi
spellingShingle	Omatsu-Kanbe, Mariko Yamamoto, Takefumi Matsuura, Hiroshi Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells
author_facet	Omatsu-Kanbe, Mariko Yamamoto, Takefumi Matsuura, Hiroshi
author_sort	Omatsu-Kanbe, Mariko
title	Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells
title_short	Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells
title_full	Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells
title_fullStr	Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells
title_full_unstemmed	Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells
title_sort	autophagy is constitutively active in normal mouse sino-atrial nodal cells
description	This study was designed to examine the autophagy in sino-atrial (SA) nodal cells from the normal adult mouse heart. Autophagy is the cellular process responsible for the degradation and recycling of long-lived and/or damaged cytoplasmic components by lysosomal digestion. In the heart, autophagy is known to occur at a low level under physiological conditions, but to become upregulated when cells are exposed to certain stresses, such as ischemia. We examined whether the basal level of autophagy in SA nodal cells was different from that in ventricular or atrial myocytes. An ultrastructural analysis revealed that the SA nodal cells contained a number of autophagic vacuoles (autophagosomes) with various stages of degradation by lysosomal digestion, whereas the number of those in ventricular or atrial myocytes was either negligible or very small. The immunostaining of autophagosome marker microtubule-associated protein 1 light chain 3 (LC3) and lysosome marker lysosome-associated membrane protein 1 (LAMP1) indicated that the content of both autophagosomes and lysosomes were much greater in SA nodal cells than in ordinary cardiomyocytes. Our results provide evidence that the autophagy is active in normal SA nodal cells, which is not a stress-activated process but a constitutive event in the mouse heart.
publisher	Japan Society of Histochemistry and Cytochemistry
publishDate	2011
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3210427/
_version_	1611485872248586240

Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells

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