Limits...
Lopinavir/Ritonavir Impairs Physical Strength in Association with Reduced Igf1 Expression in Skeletal Muscle of Older Mice.

Wong S, Bhasin S, Serra C, Yu Y, Deng L, Guo W - J AIDS Clin Res (2013)

Bottom Line: Spontaneous movements were also reduced in Kaletra-treated old mice.Kaletra reduced IGF-1 expression in all muscle groups tested for the old and in cultured myotubes but to a less extent in the muscle of young animals.This effect was worse in older animals than in normal young adults.

View Article: PubMed Central - PubMed

Affiliation: Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function promoting Anabolic Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, USA.

ABSTRACT

Background: Late-middle age HIV patients are prone to fatigue despite effective viral control by antiretroviral therapies. Rodent models to recapitulate this phenotype are still not available.

Hypothesis: Drug treatment may compromise muscle strength and physical performance more in older individuals with pre-existing metabolic disorders than normal young ones.

Methods: Kaletra was given to overweight male mice at late-middle age and normal young adults; both on a rodent diet containing 30% fat calorie. Body composition and grip strength were measured at baseline and after drug treatment. Rota-rod running, insulin and glucose tolerance were measured at the end of the experiment. Drug effect on metabolic activity and spontaneous movements were assessed using the metabolic cage system. Representative muscle and fat tissue were analyzed for protein and mRNA expression. Selected findings were tested using murine C2C12 myotubes.

Results: Kaletra reduced grip strength in both young and older mice but impaired rotarod performance only in the old. Spontaneous movements were also reduced in Kaletra-treated old mice. Kaletra reduced IGF-1 expression in all muscle groups tested for the old and in cultured myotubes but to a less extent in the muscle of young animals. Reduced IGF-1 expression correlated with increased expression of muscle-specific atrogene MAFbx and MuRF1. Kaletra also increased abdominal fat mass markedly in the old animals and to a less extend in the young.

Conclusion: Long-term Kaletra intake aggravated abdominal obesity and impaired muscle strength. This effect was worse in older animals than in normal young adults.

No MeSH data available.


Related in: MedlinePlus

Effects of Kaletra on muscle IGF1-related molecular changes in skeletal muscle and cultured myotubes(A) Messenger RNA expression of IGF-1Ea and related muscle atrogenes in tibialis anterior (TA), quadriceps (Quad) and gastrocnemius (Gastro) muscle groups. Expression of each gene was first normalized to house-keeping gene HPRT and presented as a fraction of the control. (B, left panel) Western analysis of phosphor-Foxo3aser318/321, phosphor-Foxo1ser256, and total Foxo3a in quadriceps muscle, with GAPDH as loading control. (B, right panel) Western analysis for phosphor-mTORser2448, phosphor-eiF4Gser1108, phosphor-eiF4Bser422, and phosphor-S6ser235/236 in quadriceps, with GAPDH as loading control. Results are representative of N = 6 for each group with three of each group for display. (C) Expression of IGF1, myogenin (MyoG), MAFbx and MuRF1 in cultured C2C12 myotubes exposed to different concentration of lopinavir (lopinavir:ritonavir = 4:1). The experiment was repeated twice in duplicates. Results were normalized to house-keeping gene HPRT and shown as means+/− se, a > b > c, p < 0.05, analyzed by One-way ANOVA with post hoc Tukey’s test. (D) Western analysis of C2C12 myotubes treated with low and high dose of IGF1 for the phosphorylation of relevant downstream targets. Myotubes were pre-incubated with lopinavir/ritonavir (4:1) at 3 ug/ml of lopinavir in 2% horse serum for 24 h. Cells were then washed with serum-free medium and incubated with serum-free medium added the same concentration of lopinavir/ritonavir for two hours. IGF1 was then added and cells were harvested after 30 mins. Results are representative of three independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4524660&req=5

Figure 4: Effects of Kaletra on muscle IGF1-related molecular changes in skeletal muscle and cultured myotubes(A) Messenger RNA expression of IGF-1Ea and related muscle atrogenes in tibialis anterior (TA), quadriceps (Quad) and gastrocnemius (Gastro) muscle groups. Expression of each gene was first normalized to house-keeping gene HPRT and presented as a fraction of the control. (B, left panel) Western analysis of phosphor-Foxo3aser318/321, phosphor-Foxo1ser256, and total Foxo3a in quadriceps muscle, with GAPDH as loading control. (B, right panel) Western analysis for phosphor-mTORser2448, phosphor-eiF4Gser1108, phosphor-eiF4Bser422, and phosphor-S6ser235/236 in quadriceps, with GAPDH as loading control. Results are representative of N = 6 for each group with three of each group for display. (C) Expression of IGF1, myogenin (MyoG), MAFbx and MuRF1 in cultured C2C12 myotubes exposed to different concentration of lopinavir (lopinavir:ritonavir = 4:1). The experiment was repeated twice in duplicates. Results were normalized to house-keeping gene HPRT and shown as means+/− se, a > b > c, p < 0.05, analyzed by One-way ANOVA with post hoc Tukey’s test. (D) Western analysis of C2C12 myotubes treated with low and high dose of IGF1 for the phosphorylation of relevant downstream targets. Myotubes were pre-incubated with lopinavir/ritonavir (4:1) at 3 ug/ml of lopinavir in 2% horse serum for 24 h. Cells were then washed with serum-free medium and incubated with serum-free medium added the same concentration of lopinavir/ritonavir for two hours. IGF1 was then added and cells were harvested after 30 mins. Results are representative of three independent experiments.

Mentions: Insulin-like growth factor IGF-1Ea is a locally produced autocrine/paracrine that promotes muscle repair and regeneration while suppressing catabolism, which also contributes to muscle strength [28–30]. As shown in Figure 4A, IGF-1Ea was down regulated by Kaletra in all three muscle groups tested, with a reciprocal correlation with expression of MuRF1 and MAFbx, two of the muscle-specific E3 ubiquitin ligases typically up-regulated in acute muscle atrophy [28]. Western analysis shows that Kaletra reduced phosphorylation (inactivated form) of Foxo3a and, to a less extent, Foxo1, the downstream target of IGF1 and also the transcription factors of MuRF1 and MAFbx. As shown in Figure 4B (right panel), loss of muscle IGF-1Ea was associated with reduced phosphorylation (activated form) of mTOR, the master anabolic regulator, and its downstream target eiF4G, implying that long-term treatment with Kaletra negatively regulates protein translation in muscle. However, Kaletra equally inhibited not every component in this pathway. For instance, Kaletra (Figure 4B) did not reduce phosphorylation (activated form) of eiF4B and S6. The discordance may suggest activation of endogenous compensatory mechanism at various levels trying to maintain protein translation, which might explain the relatively well-maintained muscle mass (Figure 2B).


Lopinavir/Ritonavir Impairs Physical Strength in Association with Reduced Igf1 Expression in Skeletal Muscle of Older Mice.

Wong S, Bhasin S, Serra C, Yu Y, Deng L, Guo W - J AIDS Clin Res (2013)

Effects of Kaletra on muscle IGF1-related molecular changes in skeletal muscle and cultured myotubes(A) Messenger RNA expression of IGF-1Ea and related muscle atrogenes in tibialis anterior (TA), quadriceps (Quad) and gastrocnemius (Gastro) muscle groups. Expression of each gene was first normalized to house-keeping gene HPRT and presented as a fraction of the control. (B, left panel) Western analysis of phosphor-Foxo3aser318/321, phosphor-Foxo1ser256, and total Foxo3a in quadriceps muscle, with GAPDH as loading control. (B, right panel) Western analysis for phosphor-mTORser2448, phosphor-eiF4Gser1108, phosphor-eiF4Bser422, and phosphor-S6ser235/236 in quadriceps, with GAPDH as loading control. Results are representative of N = 6 for each group with three of each group for display. (C) Expression of IGF1, myogenin (MyoG), MAFbx and MuRF1 in cultured C2C12 myotubes exposed to different concentration of lopinavir (lopinavir:ritonavir = 4:1). The experiment was repeated twice in duplicates. Results were normalized to house-keeping gene HPRT and shown as means+/− se, a > b > c, p < 0.05, analyzed by One-way ANOVA with post hoc Tukey’s test. (D) Western analysis of C2C12 myotubes treated with low and high dose of IGF1 for the phosphorylation of relevant downstream targets. Myotubes were pre-incubated with lopinavir/ritonavir (4:1) at 3 ug/ml of lopinavir in 2% horse serum for 24 h. Cells were then washed with serum-free medium and incubated with serum-free medium added the same concentration of lopinavir/ritonavir for two hours. IGF1 was then added and cells were harvested after 30 mins. Results are representative of three independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4524660&req=5

Figure 4: Effects of Kaletra on muscle IGF1-related molecular changes in skeletal muscle and cultured myotubes(A) Messenger RNA expression of IGF-1Ea and related muscle atrogenes in tibialis anterior (TA), quadriceps (Quad) and gastrocnemius (Gastro) muscle groups. Expression of each gene was first normalized to house-keeping gene HPRT and presented as a fraction of the control. (B, left panel) Western analysis of phosphor-Foxo3aser318/321, phosphor-Foxo1ser256, and total Foxo3a in quadriceps muscle, with GAPDH as loading control. (B, right panel) Western analysis for phosphor-mTORser2448, phosphor-eiF4Gser1108, phosphor-eiF4Bser422, and phosphor-S6ser235/236 in quadriceps, with GAPDH as loading control. Results are representative of N = 6 for each group with three of each group for display. (C) Expression of IGF1, myogenin (MyoG), MAFbx and MuRF1 in cultured C2C12 myotubes exposed to different concentration of lopinavir (lopinavir:ritonavir = 4:1). The experiment was repeated twice in duplicates. Results were normalized to house-keeping gene HPRT and shown as means+/− se, a > b > c, p < 0.05, analyzed by One-way ANOVA with post hoc Tukey’s test. (D) Western analysis of C2C12 myotubes treated with low and high dose of IGF1 for the phosphorylation of relevant downstream targets. Myotubes were pre-incubated with lopinavir/ritonavir (4:1) at 3 ug/ml of lopinavir in 2% horse serum for 24 h. Cells were then washed with serum-free medium and incubated with serum-free medium added the same concentration of lopinavir/ritonavir for two hours. IGF1 was then added and cells were harvested after 30 mins. Results are representative of three independent experiments.
Mentions: Insulin-like growth factor IGF-1Ea is a locally produced autocrine/paracrine that promotes muscle repair and regeneration while suppressing catabolism, which also contributes to muscle strength [28–30]. As shown in Figure 4A, IGF-1Ea was down regulated by Kaletra in all three muscle groups tested, with a reciprocal correlation with expression of MuRF1 and MAFbx, two of the muscle-specific E3 ubiquitin ligases typically up-regulated in acute muscle atrophy [28]. Western analysis shows that Kaletra reduced phosphorylation (inactivated form) of Foxo3a and, to a less extent, Foxo1, the downstream target of IGF1 and also the transcription factors of MuRF1 and MAFbx. As shown in Figure 4B (right panel), loss of muscle IGF-1Ea was associated with reduced phosphorylation (activated form) of mTOR, the master anabolic regulator, and its downstream target eiF4G, implying that long-term treatment with Kaletra negatively regulates protein translation in muscle. However, Kaletra equally inhibited not every component in this pathway. For instance, Kaletra (Figure 4B) did not reduce phosphorylation (activated form) of eiF4B and S6. The discordance may suggest activation of endogenous compensatory mechanism at various levels trying to maintain protein translation, which might explain the relatively well-maintained muscle mass (Figure 2B).

Bottom Line: Spontaneous movements were also reduced in Kaletra-treated old mice.Kaletra reduced IGF-1 expression in all muscle groups tested for the old and in cultured myotubes but to a less extent in the muscle of young animals.This effect was worse in older animals than in normal young adults.

View Article: PubMed Central - PubMed

Affiliation: Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function promoting Anabolic Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, USA.

ABSTRACT

Background: Late-middle age HIV patients are prone to fatigue despite effective viral control by antiretroviral therapies. Rodent models to recapitulate this phenotype are still not available.

Hypothesis: Drug treatment may compromise muscle strength and physical performance more in older individuals with pre-existing metabolic disorders than normal young ones.

Methods: Kaletra was given to overweight male mice at late-middle age and normal young adults; both on a rodent diet containing 30% fat calorie. Body composition and grip strength were measured at baseline and after drug treatment. Rota-rod running, insulin and glucose tolerance were measured at the end of the experiment. Drug effect on metabolic activity and spontaneous movements were assessed using the metabolic cage system. Representative muscle and fat tissue were analyzed for protein and mRNA expression. Selected findings were tested using murine C2C12 myotubes.

Results: Kaletra reduced grip strength in both young and older mice but impaired rotarod performance only in the old. Spontaneous movements were also reduced in Kaletra-treated old mice. Kaletra reduced IGF-1 expression in all muscle groups tested for the old and in cultured myotubes but to a less extent in the muscle of young animals. Reduced IGF-1 expression correlated with increased expression of muscle-specific atrogene MAFbx and MuRF1. Kaletra also increased abdominal fat mass markedly in the old animals and to a less extend in the young.

Conclusion: Long-term Kaletra intake aggravated abdominal obesity and impaired muscle strength. This effect was worse in older animals than in normal young adults.

No MeSH data available.


Related in: MedlinePlus