Limits...
The E3 ubiquitin ligase TRIM62 and inflammation-induced skeletal muscle atrophy.

Schmidt F, Kny M, Zhu X, Wollersheim T, Persicke K, Langhans C, Lodka D, Kleber C, Weber-Carstens S, Fielitz J - Crit Care (2014)

Bottom Line: Trim62 was expressed in myocytes, and its overexpression activated the atrophy-inducing activator protein 1 signal transduction pathway.Knockdown of Trim62 by small interfering RNA inhibited lipopolysaccharide-induced interleukin 6 expression.It could play a role in the pathogenesis of ICUAW by activating and maintaining inflammation in myocytes.

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: ICU-acquired weakness (ICUAW) complicates the disease course of critically ill patients. Inflammation and acute-phase response occur directly within myocytes and contribute to ICUAW. We observed that tripartite motif-containing 62 (TRIM62), an E3 ubiquitin ligase and modifier of inflammation, is increased in the skeletal muscle of ICUAW patients. We investigated the regulation and function of muscular TRIM62 in critical illness.

Methods: Twenty-six critically ill patients with Sequential Organ Failure Assessment scores ≥8 underwent two skeletal muscle biopsies from the vastus lateralis at median days 5 and 15 in the ICU. Four patients undergoing elective orthopedic surgery served as controls. TRIM62 expression and protein content were analyzed in these biopsies. The kinetics of Trim62, Atrogin1 and MuRF1 expression were determined in the gastrocnemius/plantaris and tibialis anterior muscles from mouse models of inflammation-, denervation- and starvation-induced muscle atrophy to differentiate between these contributors to ICUAW. Cultured myocytes were used for mechanistic analyses.

Results: TRIM62 expression and protein content were increased early and remained elevated in muscles from critically ill patients. In all three animal models, muscular Trim62 expression was early and continuously increased. Trim62 was expressed in myocytes, and its overexpression activated the atrophy-inducing activator protein 1 signal transduction pathway. Knockdown of Trim62 by small interfering RNA inhibited lipopolysaccharide-induced interleukin 6 expression.

Conclusions: TRIM62 is activated in the muscles of critically ill patients. It could play a role in the pathogenesis of ICUAW by activating and maintaining inflammation in myocytes.

Trial registration: Current Controlled Trials ID: ISRCTN77569430 (registered 13 February 2008).

Show MeSH

Related in: MedlinePlus

MuscularTRIM62expression in critically ill patients. (A) Quantitative RT-PCR analyses of tripartite motif–containing 62 (TRIM62) expression in vastus lateralis muscles of orthopedic control patients (n =4) and patients with ICU-acquired weakness (ICUAW) at early (day 5, n =26) and late (day 15, n =14) time points. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression was used as the reference. Data shown are relative expression and fold changes compared to control patients. Data presented in box plots are medians and 25th and 75th percentiles. **P <0.01. (B) Immunoblots of proteins from vastus lateralis muscles of orthopedic control and critically ill patients at early (day 5) and late (day 15) time points using anti-TRIM62 antibody. GAPDH was used as loading control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4231194&req=5

Fig1: MuscularTRIM62expression in critically ill patients. (A) Quantitative RT-PCR analyses of tripartite motif–containing 62 (TRIM62) expression in vastus lateralis muscles of orthopedic control patients (n =4) and patients with ICU-acquired weakness (ICUAW) at early (day 5, n =26) and late (day 15, n =14) time points. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression was used as the reference. Data shown are relative expression and fold changes compared to control patients. Data presented in box plots are medians and 25th and 75th percentiles. **P <0.01. (B) Immunoblots of proteins from vastus lateralis muscles of orthopedic control and critically ill patients at early (day 5) and late (day 15) time points using anti-TRIM62 antibody. GAPDH was used as loading control.

Mentions: The study protocol (Additional file 2: Figure S1), data on patients’ characteristics (Additional file 1: Table S1) and treatment (Additional file 1: Table S2) are provided. The data from our microarray have been deposited in the National Center for Biotechnology Information Gene Expression Omnibus (GEO) database [GEO:GSE53702] (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE53702). We found a 3.9-fold upregulation of TRIM62 [13]. We performed qRT-PCR in a subset of our recently published ICU patients [8] at the early (day 5, n =26) and late (day 15, n =14) time points and orthopedic controls (n =4) to confirm these data. Continuous upregulation of muscular TRIM62 mRNA was confirmed for both time points of critical illness (P <0.01) (Figure 1A). Immunoblot analysis showed that muscular TRIM62 protein was increased at the early time point and remained elevated until the late time point in critically ill patients (Figure 1B). In contrast, Atrogin1 and MuRF1 expression was significantly increased in the early and returned to control levels in the late biopsy specimens in these patients as recently reported [8].Figure 1


The E3 ubiquitin ligase TRIM62 and inflammation-induced skeletal muscle atrophy.

Schmidt F, Kny M, Zhu X, Wollersheim T, Persicke K, Langhans C, Lodka D, Kleber C, Weber-Carstens S, Fielitz J - Crit Care (2014)

MuscularTRIM62expression in critically ill patients. (A) Quantitative RT-PCR analyses of tripartite motif–containing 62 (TRIM62) expression in vastus lateralis muscles of orthopedic control patients (n =4) and patients with ICU-acquired weakness (ICUAW) at early (day 5, n =26) and late (day 15, n =14) time points. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression was used as the reference. Data shown are relative expression and fold changes compared to control patients. Data presented in box plots are medians and 25th and 75th percentiles. **P <0.01. (B) Immunoblots of proteins from vastus lateralis muscles of orthopedic control and critically ill patients at early (day 5) and late (day 15) time points using anti-TRIM62 antibody. GAPDH was used as loading control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4231194&req=5

Fig1: MuscularTRIM62expression in critically ill patients. (A) Quantitative RT-PCR analyses of tripartite motif–containing 62 (TRIM62) expression in vastus lateralis muscles of orthopedic control patients (n =4) and patients with ICU-acquired weakness (ICUAW) at early (day 5, n =26) and late (day 15, n =14) time points. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression was used as the reference. Data shown are relative expression and fold changes compared to control patients. Data presented in box plots are medians and 25th and 75th percentiles. **P <0.01. (B) Immunoblots of proteins from vastus lateralis muscles of orthopedic control and critically ill patients at early (day 5) and late (day 15) time points using anti-TRIM62 antibody. GAPDH was used as loading control.
Mentions: The study protocol (Additional file 2: Figure S1), data on patients’ characteristics (Additional file 1: Table S1) and treatment (Additional file 1: Table S2) are provided. The data from our microarray have been deposited in the National Center for Biotechnology Information Gene Expression Omnibus (GEO) database [GEO:GSE53702] (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE53702). We found a 3.9-fold upregulation of TRIM62 [13]. We performed qRT-PCR in a subset of our recently published ICU patients [8] at the early (day 5, n =26) and late (day 15, n =14) time points and orthopedic controls (n =4) to confirm these data. Continuous upregulation of muscular TRIM62 mRNA was confirmed for both time points of critical illness (P <0.01) (Figure 1A). Immunoblot analysis showed that muscular TRIM62 protein was increased at the early time point and remained elevated until the late time point in critically ill patients (Figure 1B). In contrast, Atrogin1 and MuRF1 expression was significantly increased in the early and returned to control levels in the late biopsy specimens in these patients as recently reported [8].Figure 1

Bottom Line: Trim62 was expressed in myocytes, and its overexpression activated the atrophy-inducing activator protein 1 signal transduction pathway.Knockdown of Trim62 by small interfering RNA inhibited lipopolysaccharide-induced interleukin 6 expression.It could play a role in the pathogenesis of ICUAW by activating and maintaining inflammation in myocytes.

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: ICU-acquired weakness (ICUAW) complicates the disease course of critically ill patients. Inflammation and acute-phase response occur directly within myocytes and contribute to ICUAW. We observed that tripartite motif-containing 62 (TRIM62), an E3 ubiquitin ligase and modifier of inflammation, is increased in the skeletal muscle of ICUAW patients. We investigated the regulation and function of muscular TRIM62 in critical illness.

Methods: Twenty-six critically ill patients with Sequential Organ Failure Assessment scores ≥8 underwent two skeletal muscle biopsies from the vastus lateralis at median days 5 and 15 in the ICU. Four patients undergoing elective orthopedic surgery served as controls. TRIM62 expression and protein content were analyzed in these biopsies. The kinetics of Trim62, Atrogin1 and MuRF1 expression were determined in the gastrocnemius/plantaris and tibialis anterior muscles from mouse models of inflammation-, denervation- and starvation-induced muscle atrophy to differentiate between these contributors to ICUAW. Cultured myocytes were used for mechanistic analyses.

Results: TRIM62 expression and protein content were increased early and remained elevated in muscles from critically ill patients. In all three animal models, muscular Trim62 expression was early and continuously increased. Trim62 was expressed in myocytes, and its overexpression activated the atrophy-inducing activator protein 1 signal transduction pathway. Knockdown of Trim62 by small interfering RNA inhibited lipopolysaccharide-induced interleukin 6 expression.

Conclusions: TRIM62 is activated in the muscles of critically ill patients. It could play a role in the pathogenesis of ICUAW by activating and maintaining inflammation in myocytes.

Trial registration: Current Controlled Trials ID: ISRCTN77569430 (registered 13 February 2008).

Show MeSH
Related in: MedlinePlus