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The NF-kappaB inhibitor curcumin blocks sepsis-induced muscle proteolysis.

Poylin V, Fareed MU, O'Neal P, Alamdari N, Reilly N, Menconi M, Hasselgren PO - Mediators Inflamm. (2008)

Bottom Line: Protein breakdown rates were measured as release of tyrosine from incubated extensor digitorum longus muscles.Surprisingly, the upregulated expression of the ubiquitin ligases atrogin-1 and MuRF1 was not influenced by curcumin.When muscles from septic rats were treated with curcumin in vitro, proteasome-, calpain-, and cathepsin L-dependent protein breakdown rates were reduced, and nuclear NF-kappaB/p65 expression and activity as well as levels of phosphorylated (activated) p38 were decreased.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.

ABSTRACT
We tested the hypothesis that treatment of rats with curcumin prevents sepsis-induced muscle protein degradation. In addition, we determined the influence of curcumin on different proteolytic pathways that are activated in septic muscle (i.e., ubiquitin-proteasome-, calpain-, and cathepsin L-dependent proteolysis) and examined the role of NF-kappaB and p38/MAP kinase inactivation in curcumin-induced inhibition of muscle protein breakdown. Rats were made septic by cecal ligation and puncture or were sham-operated. Groups of rats were treated with three intraperitoneal doses (600 mg/kg) of curcumin or corresponding volumes of solvent. Protein breakdown rates were measured as release of tyrosine from incubated extensor digitorum longus muscles. Treatment with curcumin prevented sepsis-induced increase in muscle protein breakdown. Surprisingly, the upregulated expression of the ubiquitin ligases atrogin-1 and MuRF1 was not influenced by curcumin. When muscles from septic rats were treated with curcumin in vitro, proteasome-, calpain-, and cathepsin L-dependent protein breakdown rates were reduced, and nuclear NF-kappaB/p65 expression and activity as well as levels of phosphorylated (activated) p38 were decreased. Results suggest that sepsis-induced muscle proteolysis can be blocked by curcumin and that this effect may, at least in part, be caused by inhibited NF-kappaB and p38 activities. The results also suggest that there is not an absolute correlation between changes in muscle protein breakdown rates and changes in atrogin-1 and MuRF1 expression during treatment of muscle wasting.

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Treatment of incubated muscles in vitro with curcumin reduces sepsis-induced increase in protein breakdown. (a) Extensor digitorum longus muscles were harvested from rats 16 hours after sham-operation or CLP and incubated for 2 hours in the absence or presence of curcumin (100 μM) dissolved in 0.1% DMSO. Protein breakdown rates were measured as net release of tyrosine as described in Section 2. Results are means ± SEM with n = 8 in each group. *P < .05 versus all other groups by ANOVA. (b) Incubated muscles from septic rats (16 hours after CLP) were treated with different concentrations of curcumin for 2 hours followed by measurement of tyrosine release. Results are means ± SEM with n = 8  in each group except for “0 curcumin” which was pooled from 3 paired experiments (0 versus 50, 0 versus 100, and 0 versus 500 μM). Results are expressed as % of control.
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fig5: Treatment of incubated muscles in vitro with curcumin reduces sepsis-induced increase in protein breakdown. (a) Extensor digitorum longus muscles were harvested from rats 16 hours after sham-operation or CLP and incubated for 2 hours in the absence or presence of curcumin (100 μM) dissolved in 0.1% DMSO. Protein breakdown rates were measured as net release of tyrosine as described in Section 2. Results are means ± SEM with n = 8 in each group. *P < .05 versus all other groups by ANOVA. (b) Incubated muscles from septic rats (16 hours after CLP) were treated with different concentrations of curcumin for 2 hours followed by measurement of tyrosine release. Results are means ± SEM with n = 8 in each group except for “0 curcumin” which was pooled from 3 paired experiments (0 versus 50, 0 versus 100, and 0 versus 500 μM). Results are expressed as % of control.

Mentions: Having established that treatment of rats in vivo with curcumin blocked the sepsis-induced increase in muscle proteolysis, we next examined whether the drug has a direct effect in skeletal muscle. This was done by exposingincubated muscles to curcumin in vitro. When muscles from sham-operated andseptic rats were incubated in the presence of 100 μM curcumin, the increased protein degradation seen in septic muscle was reduced to control levels (Figure 5(a)). This result isimportant because it suggests that curcumin can exert anabolic effects incatabolic muscle by a direct effect and that muscle proteolysis that hasalready been increased by sepsis can be reversed by curcumin. Similar to the results observed in vivo, treatment with curcumin in vitro did not result in a significant inhibition of protein breakdown rates in muscles from sham-operated rats (Figure 5). Therefore, in subsequent experiments in the present study, designed to elucidate mechanisms by which curcumin exerts its effects in catabolic muscle, we used muscles from septic rats. Because treatment of incubated muscles from septic rats with different concentrations of curcumin suggested that a maximal effect was achieved with 100 μM curcumin (Figure 5(b)), this concentration wasused in subsequent experiments.


The NF-kappaB inhibitor curcumin blocks sepsis-induced muscle proteolysis.

Poylin V, Fareed MU, O'Neal P, Alamdari N, Reilly N, Menconi M, Hasselgren PO - Mediators Inflamm. (2008)

Treatment of incubated muscles in vitro with curcumin reduces sepsis-induced increase in protein breakdown. (a) Extensor digitorum longus muscles were harvested from rats 16 hours after sham-operation or CLP and incubated for 2 hours in the absence or presence of curcumin (100 μM) dissolved in 0.1% DMSO. Protein breakdown rates were measured as net release of tyrosine as described in Section 2. Results are means ± SEM with n = 8 in each group. *P < .05 versus all other groups by ANOVA. (b) Incubated muscles from septic rats (16 hours after CLP) were treated with different concentrations of curcumin for 2 hours followed by measurement of tyrosine release. Results are means ± SEM with n = 8  in each group except for “0 curcumin” which was pooled from 3 paired experiments (0 versus 50, 0 versus 100, and 0 versus 500 μM). Results are expressed as % of control.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2279164&req=5

fig5: Treatment of incubated muscles in vitro with curcumin reduces sepsis-induced increase in protein breakdown. (a) Extensor digitorum longus muscles were harvested from rats 16 hours after sham-operation or CLP and incubated for 2 hours in the absence or presence of curcumin (100 μM) dissolved in 0.1% DMSO. Protein breakdown rates were measured as net release of tyrosine as described in Section 2. Results are means ± SEM with n = 8 in each group. *P < .05 versus all other groups by ANOVA. (b) Incubated muscles from septic rats (16 hours after CLP) were treated with different concentrations of curcumin for 2 hours followed by measurement of tyrosine release. Results are means ± SEM with n = 8 in each group except for “0 curcumin” which was pooled from 3 paired experiments (0 versus 50, 0 versus 100, and 0 versus 500 μM). Results are expressed as % of control.
Mentions: Having established that treatment of rats in vivo with curcumin blocked the sepsis-induced increase in muscle proteolysis, we next examined whether the drug has a direct effect in skeletal muscle. This was done by exposingincubated muscles to curcumin in vitro. When muscles from sham-operated andseptic rats were incubated in the presence of 100 μM curcumin, the increased protein degradation seen in septic muscle was reduced to control levels (Figure 5(a)). This result isimportant because it suggests that curcumin can exert anabolic effects incatabolic muscle by a direct effect and that muscle proteolysis that hasalready been increased by sepsis can be reversed by curcumin. Similar to the results observed in vivo, treatment with curcumin in vitro did not result in a significant inhibition of protein breakdown rates in muscles from sham-operated rats (Figure 5). Therefore, in subsequent experiments in the present study, designed to elucidate mechanisms by which curcumin exerts its effects in catabolic muscle, we used muscles from septic rats. Because treatment of incubated muscles from septic rats with different concentrations of curcumin suggested that a maximal effect was achieved with 100 μM curcumin (Figure 5(b)), this concentration wasused in subsequent experiments.

Bottom Line: Protein breakdown rates were measured as release of tyrosine from incubated extensor digitorum longus muscles.Surprisingly, the upregulated expression of the ubiquitin ligases atrogin-1 and MuRF1 was not influenced by curcumin.When muscles from septic rats were treated with curcumin in vitro, proteasome-, calpain-, and cathepsin L-dependent protein breakdown rates were reduced, and nuclear NF-kappaB/p65 expression and activity as well as levels of phosphorylated (activated) p38 were decreased.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.

ABSTRACT
We tested the hypothesis that treatment of rats with curcumin prevents sepsis-induced muscle protein degradation. In addition, we determined the influence of curcumin on different proteolytic pathways that are activated in septic muscle (i.e., ubiquitin-proteasome-, calpain-, and cathepsin L-dependent proteolysis) and examined the role of NF-kappaB and p38/MAP kinase inactivation in curcumin-induced inhibition of muscle protein breakdown. Rats were made septic by cecal ligation and puncture or were sham-operated. Groups of rats were treated with three intraperitoneal doses (600 mg/kg) of curcumin or corresponding volumes of solvent. Protein breakdown rates were measured as release of tyrosine from incubated extensor digitorum longus muscles. Treatment with curcumin prevented sepsis-induced increase in muscle protein breakdown. Surprisingly, the upregulated expression of the ubiquitin ligases atrogin-1 and MuRF1 was not influenced by curcumin. When muscles from septic rats were treated with curcumin in vitro, proteasome-, calpain-, and cathepsin L-dependent protein breakdown rates were reduced, and nuclear NF-kappaB/p65 expression and activity as well as levels of phosphorylated (activated) p38 were decreased. Results suggest that sepsis-induced muscle proteolysis can be blocked by curcumin and that this effect may, at least in part, be caused by inhibited NF-kappaB and p38 activities. The results also suggest that there is not an absolute correlation between changes in muscle protein breakdown rates and changes in atrogin-1 and MuRF1 expression during treatment of muscle wasting.

Show MeSH
Related in: MedlinePlus