Pre-surgical miR-675-5p associates with the inflammatory response to surgery and increases inflammatory gene expression in vitro
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Background
A loss of muscle mass and strength is a marker of poor outcomes following surgery. Changes in
muscle gene expression following surgery are likely to contribute to post-surgical muscle loss, but
the mechanisms controlling these changes are not known. We have previously shown that miRNAs
associate with muscle loss in disease, including surgery, so may contribute to changes in gene
expression. We analysed the change in muscle gene expression following surgery and compared it
to pre- and post-surgical miRNA expression. We then analysed the effect of one of these miRNAs
(miR-675-5p) on gene expression in myoblasts in the presence and absence of an inflammatory
stimulus.
Methods
Differential gene expression analysis was performed on RNAseq data from rectus femoris biopsies
(n=18 male patients) pre- and post-surgery. Gene expression was compared with miRNA
expression in the same samples to identify patterns of mRNA expression associated with
physiology and miRNA expression. The effect of miR-675-5p on gene expression in the presence
and absence of TNF-a was determined in LHCN myoblasts by RNAseq.
Results
Post-surgery muscle had increased expression of gene sets associated with TNF-a signalling (2.7
fold) and MYC targets (2.7-fold). Loss of muscle mass and strength associated with MYC target
gene sets, but inflammatory gene sets only associated with loss of strength.
Comparing miRNA expression with post-surgery gene expression showed that pre-surgery miR
675-5p expression was most closely associated with post-surgical gene expression, indicating that
the pre-surgery phenotype is important in determining the response to surgery. Pre-surgery miR
675-5p correlated with change in gene expression in response to surgery (b=1.30, p<0.001), such
that individuals with the highest pre-surgery miR-675-5p had the largest change in gene expression in response to surgery.
In LHCN myoblasts miR-675-5p increased CCL2 protein release approximately 1.5-fold (p<0.001). RNAseq showed that, in the absence of TNF-a, transfection with miR-675-5p increased the expression of 3422 genes with greatest enrichment of the hypoxia, myogenesis and TNF-a signalling via NF-kB gene sets. In the presence of TNF-a, miR-675-5p increased the expression of 3403 genes and the most enriched gene sets were the same suggesting that miR-675-5p increases the inflammatory response. miR-675-5p also increased the expression of MuRF1 in the presence
and absence of TNF-a.
Conclusions
Male patients with higher pre-surgical expression of miR-675-5p experienced a larger increase in
inflammatory gene expression following surgery. MiR-675-5p increased inflammatory gene expression in myoblasts suggesting that it may contribute to the size of the inflammatory
response.
A loss of muscle mass and strength is a marker of poor outcomes following surgery. Changes in
muscle gene expression following surgery are likely to contribute to post-surgical muscle loss, but
the mechanisms controlling these changes are not known. We have previously shown that miRNAs
associate with muscle loss in disease, including surgery, so may contribute to changes in gene
expression. We analysed the change in muscle gene expression following surgery and compared it
to pre- and post-surgical miRNA expression. We then analysed the effect of one of these miRNAs
(miR-675-5p) on gene expression in myoblasts in the presence and absence of an inflammatory
stimulus.
Methods
Differential gene expression analysis was performed on RNAseq data from rectus femoris biopsies
(n=18 male patients) pre- and post-surgery. Gene expression was compared with miRNA
expression in the same samples to identify patterns of mRNA expression associated with
physiology and miRNA expression. The effect of miR-675-5p on gene expression in the presence
and absence of TNF-a was determined in LHCN myoblasts by RNAseq.
Results
Post-surgery muscle had increased expression of gene sets associated with TNF-a signalling (2.7
fold) and MYC targets (2.7-fold). Loss of muscle mass and strength associated with MYC target
gene sets, but inflammatory gene sets only associated with loss of strength.
Comparing miRNA expression with post-surgery gene expression showed that pre-surgery miR
675-5p expression was most closely associated with post-surgical gene expression, indicating that
the pre-surgery phenotype is important in determining the response to surgery. Pre-surgery miR
675-5p correlated with change in gene expression in response to surgery (b=1.30, p<0.001), such
that individuals with the highest pre-surgery miR-675-5p had the largest change in gene expression in response to surgery.
In LHCN myoblasts miR-675-5p increased CCL2 protein release approximately 1.5-fold (p<0.001). RNAseq showed that, in the absence of TNF-a, transfection with miR-675-5p increased the expression of 3422 genes with greatest enrichment of the hypoxia, myogenesis and TNF-a signalling via NF-kB gene sets. In the presence of TNF-a, miR-675-5p increased the expression of 3403 genes and the most enriched gene sets were the same suggesting that miR-675-5p increases the inflammatory response. miR-675-5p also increased the expression of MuRF1 in the presence
and absence of TNF-a.
Conclusions
Male patients with higher pre-surgical expression of miR-675-5p experienced a larger increase in
inflammatory gene expression following surgery. MiR-675-5p increased inflammatory gene expression in myoblasts suggesting that it may contribute to the size of the inflammatory
response.
Date Acceptance
2026-07-22
Citation
Journal of Cachexia, Sarcopenia and Muscle
ISSN
2190-5991
Publisher
Wiley
Journal / Book Title
Journal of Cachexia, Sarcopenia and Muscle
Copyright Statement
Copyright This paper is embargoed until publication. Once published the Version of Record (VoR) will be available on immediate open access.
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Publication Status
Accepted