Morphometry of skeletal muscle capillaries: the relationship between capillary ultrastructure and ageing in humans.
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BORIS DOI
Date of Publication
October 2016
Publication Type
Article
Division/Institute
Author
Koutsantonis, D. | |
Odriozola, A. | |
Zakrzewicz, A. | |
Weichert, A. | |
Baum, O. |
Subject(s)
Series
Acta physiologica
ISSN or ISBN (if monograph)
1748-1708
Publisher
Wiley
Language
English
Publisher DOI
PubMed ID
27174490
Uncontrolled Keywords
Description
AIM
To determine whether the ultrastructure of the capillary system in human skeletal muscle changes during advancing senescence, we evaluated the compartmental and subcompartmental organization of capillaries from vastus lateralis muscle (VL) biopsies of 41 non-diseased persons aged 23-75 years.
METHODS
From each VL biopsy, 38-40 randomly selected capillaries were assessed by transmission electron microscopy and subsequent morphometry with a newly established tablet-based image analysis technique.
RESULTS
Quantification of the compartmental organization revealed most indicators of the capillary ultrastructure to be only non-significantly altered (P > 0.05) over age. However, the peri-capillary basement membrane (BM) was thicker in the older participants than in the younger ones (P ≤ 0.05). Regression analysis revealed a bipartite relationship between the two parameters: a homogenous slight increase in BM thickness up to the age of approximately 50 years was followed by a second phase with more scattered BM thickness values. In 44.5% of the capillary profiles, projections/filopodia of the pericytes (PCs) traversed the BM and invaded endothelial cells (ECs) visible as PC pegs in pale cytoplasm holes (EC sockets). Strikingly, PC pegs were often in proximity to the EC nucleus. In PC profiles, sockets were likewise detected in 14.2% of the capillaries. Within these PC sockets, cellular profiles were frequently seen, which could be assigned to EC filopodia, internal PC curling or PC-PC interactions. Quantification of the occurrence of peg-socket junctions revealed the proportions of empty EC sockets and empty PC sockets to increase (P ≤ 0.05) during ageing.
CONCLUSION
Our investigation demonstrates advancing senescence to be associated with increase in BM thickness and loss of EC and PC filopodia length in skeletal muscle capillaries.
To determine whether the ultrastructure of the capillary system in human skeletal muscle changes during advancing senescence, we evaluated the compartmental and subcompartmental organization of capillaries from vastus lateralis muscle (VL) biopsies of 41 non-diseased persons aged 23-75 years.
METHODS
From each VL biopsy, 38-40 randomly selected capillaries were assessed by transmission electron microscopy and subsequent morphometry with a newly established tablet-based image analysis technique.
RESULTS
Quantification of the compartmental organization revealed most indicators of the capillary ultrastructure to be only non-significantly altered (P > 0.05) over age. However, the peri-capillary basement membrane (BM) was thicker in the older participants than in the younger ones (P ≤ 0.05). Regression analysis revealed a bipartite relationship between the two parameters: a homogenous slight increase in BM thickness up to the age of approximately 50 years was followed by a second phase with more scattered BM thickness values. In 44.5% of the capillary profiles, projections/filopodia of the pericytes (PCs) traversed the BM and invaded endothelial cells (ECs) visible as PC pegs in pale cytoplasm holes (EC sockets). Strikingly, PC pegs were often in proximity to the EC nucleus. In PC profiles, sockets were likewise detected in 14.2% of the capillaries. Within these PC sockets, cellular profiles were frequently seen, which could be assigned to EC filopodia, internal PC curling or PC-PC interactions. Quantification of the occurrence of peg-socket junctions revealed the proportions of empty EC sockets and empty PC sockets to increase (P ≤ 0.05) during ageing.
CONCLUSION
Our investigation demonstrates advancing senescence to be associated with increase in BM thickness and loss of EC and PC filopodia length in skeletal muscle capillaries.
File(s)
| File | File Type | Format | Size | License | Publisher/Copright statement | Content | |
|---|---|---|---|---|---|---|---|
| Bigler_et_al-2016-Acta_Physiologica.pdf | text | Adobe PDF | 1.82 MB | publisher | published |