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The effects of acylation stimulating protein supplementation VS antibody neutralization on energy expenditure in wildtype mice.

Paglialunga S, Fisette A, Munkonda M, Gao Y, Richard D, Cianflone K - BMC Physiol. (2010)

Bottom Line: Again, there was no change in circulating insulin, adiponectin, CRP or TG levels, however, plasma free fatty acids were reduced (-48%, P < 0.05).In vitro, Anti-ASP effectively neutralized ASP stimulated fatty acid uptake.Therefore, ASP is a potent anabolic hormone that may also be a mediator of energy expenditure.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, G1V 4G5, Canada.

ABSTRACT

Background: Acylation stimulating protein (ASP) is an adipogenic hormone that stimulates triglyceride (TG) synthesis and glucose transport in adipocytes. Previous studies have shown that ASP-deficient C3 knockout mice are hyperphagic yet lean, as they display increased oxygen consumption and fatty acid oxidation compared to wildtype mice. In the present study, antibodies against ASP (Anti-ASP) and human recombinant ASP (rASP) were tested in vitro and in vivo. Continuous administration for 4 weeks via osmotic mini-pump of Anti-ASP or rASP was evaluated in wildtype mice on a high-fat diet (HFD) to examine their effects on body weight, food intake and energy expenditure.

Results: In mature murine adipocytes, rASP significantly stimulated fatty acid uptake (+243% vs PBS, P < 0.05) while Anti-ASP neutralized the rASP response. Mice treated with Anti-ASP showed elevated energy expenditure (P < 0.0001), increased skeletal muscle glucose oxidation (+141%, P < 0.001), reduced liver glycogen (-34%, P < 0.05) and glucose-6-phosphate content (-64%, P = 0.08) compared to control mice. There was no change in body weight, food intake, fasting insulin, adiponectin, CRP or TG levels compared to controls. Interestingly, HFD mice treated with rASP showed the opposite phenotype with reduced energy expenditure (P < 0.0001) and increased body weight (P < 0.05), cumulative food intake (P < 0.0001) and liver glycogen content (+59%, P < 0.05). Again, there was no change in circulating insulin, adiponectin, CRP or TG levels, however, plasma free fatty acids were reduced (-48%, P < 0.05).

Conclusion: In vitro, Anti-ASP effectively neutralized ASP stimulated fatty acid uptake. In vivo, Anti-ASP treatment increased whole body energy utilization while rASP increased energy storage. Therefore, ASP is a potent anabolic hormone that may also be a mediator of energy expenditure.

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Related in: MedlinePlus

Plasma antibody, IL-6, CRP and indirect calorimetry results for mice treated with ASP-neutralizing antibody or control antibody. Fasting plasma samples from NI-IgG treated mice (n = 6, white bars) and Anti-ASP treated mice (n = 7, black bars). (A) Polyclonal rabbit antibody detected in mouse plasma following 9 days and 4 weeks treatment. (B) Plasma IL-6 and (C) CRP levels at end of treatment. Results were analyzed by unpaired two-tailed t-test. (D) Energy expenditure measured over 24 hours for NI-IgG treated mice (n = 6, white squares) and Anti-ASP treated mice (n = 7, black squares). Results were analyzed by two-way ANOVA. Group and time P values are reported in graph, their interaction was not significant. Analysis of light and dark periods separately (2-way ANOVA) indicated a significant difference between Anti-ASP and NI-IgG for both time periods (P < 0.0001) (E) Light and dark phase energy expenditure calculated as the area-under the curve (AUC). (F) respiratory quotient (RQ) measured over 24 hours for NI-IgG treated mice (white squares) and Anti-ASP treated mice (black squares). Results were analyzed by two-way ANOVA. Group and time P values are reported in graph, their interaction was not significant. All values are presented as mean ± SEM, where * P < 0.05.
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Figure 2: Plasma antibody, IL-6, CRP and indirect calorimetry results for mice treated with ASP-neutralizing antibody or control antibody. Fasting plasma samples from NI-IgG treated mice (n = 6, white bars) and Anti-ASP treated mice (n = 7, black bars). (A) Polyclonal rabbit antibody detected in mouse plasma following 9 days and 4 weeks treatment. (B) Plasma IL-6 and (C) CRP levels at end of treatment. Results were analyzed by unpaired two-tailed t-test. (D) Energy expenditure measured over 24 hours for NI-IgG treated mice (n = 6, white squares) and Anti-ASP treated mice (n = 7, black squares). Results were analyzed by two-way ANOVA. Group and time P values are reported in graph, their interaction was not significant. Analysis of light and dark periods separately (2-way ANOVA) indicated a significant difference between Anti-ASP and NI-IgG for both time periods (P < 0.0001) (E) Light and dark phase energy expenditure calculated as the area-under the curve (AUC). (F) respiratory quotient (RQ) measured over 24 hours for NI-IgG treated mice (white squares) and Anti-ASP treated mice (black squares). Results were analyzed by two-way ANOVA. Group and time P values are reported in graph, their interaction was not significant. All values are presented as mean ± SEM, where * P < 0.05.

Mentions: Mice were treated by osmotic mini-pump for 4 weeks with neutralizing Anti-ASP or control non-immune IgG (NI-IgG). Plasma samples were taken 9 days after implantation of the osmotic pump and at the end of the study to track the amount of antibody delivered into circulation. Figure 2A shows that on day 9 rabbit NI-IgG and Anti-ASP antibodies were detected (~4% of starting material). However, by the end, the levels of both NI-IgG and Anti-ASP were greatly reduced (~0.1% of starting material). Since there was no difference in osmotic mini-pump rate for PBS, rabbit antibodies or rASP treatments (data not shown), reduced antibody levels may be attributed to enhanced antibody clearance. Anti-ASP blocking antibody treatment had no effect on mouse body weight (NI-IgG: 29.2 ± 0.4 g and Anti-ASP: 29.6 ± 0.3 g, NS, n = 6-7), average food intake (NI-IgG: 13.8 ± 0.5 kcal/day and Anti-ASP: 14.3 ± 0.5 kcal/day, NS, n = 6-7) or food efficiency (NI-IgG: 200.1 ± 21.2 kcal/g and Anti-ASP: 165.6 ± 25.8 kcal/g, NS, n = 6-7), consistent with our previous report during a 10 day study [17]. There was also no difference in adipose tissue depots, liver or spleen weight between the two groups (data not shown). IL-6 levels were slightly but significantly elevated in Anti-ASP mice (P < 0.05, Figure 2B). However, CRP levels, a marker of inflammation, were normal (Figure 2C). Anti-ASP did not have an effect on fasting glucose levels after nine days of treatment (NI-IgG: 6.22 ± 0.62 mmol/L and Anti-ASP: 6.58 ± 0.54 mmol/L, NS, n = 6-7). Furthermore, there was no difference in plasma adiponectin, insulin, C3, or lipid levels between the two groups at the end of the study (Table 1).


The effects of acylation stimulating protein supplementation VS antibody neutralization on energy expenditure in wildtype mice.

Paglialunga S, Fisette A, Munkonda M, Gao Y, Richard D, Cianflone K - BMC Physiol. (2010)

Plasma antibody, IL-6, CRP and indirect calorimetry results for mice treated with ASP-neutralizing antibody or control antibody. Fasting plasma samples from NI-IgG treated mice (n = 6, white bars) and Anti-ASP treated mice (n = 7, black bars). (A) Polyclonal rabbit antibody detected in mouse plasma following 9 days and 4 weeks treatment. (B) Plasma IL-6 and (C) CRP levels at end of treatment. Results were analyzed by unpaired two-tailed t-test. (D) Energy expenditure measured over 24 hours for NI-IgG treated mice (n = 6, white squares) and Anti-ASP treated mice (n = 7, black squares). Results were analyzed by two-way ANOVA. Group and time P values are reported in graph, their interaction was not significant. Analysis of light and dark periods separately (2-way ANOVA) indicated a significant difference between Anti-ASP and NI-IgG for both time periods (P < 0.0001) (E) Light and dark phase energy expenditure calculated as the area-under the curve (AUC). (F) respiratory quotient (RQ) measured over 24 hours for NI-IgG treated mice (white squares) and Anti-ASP treated mice (black squares). Results were analyzed by two-way ANOVA. Group and time P values are reported in graph, their interaction was not significant. All values are presented as mean ± SEM, where * P < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC2875207&req=5

Figure 2: Plasma antibody, IL-6, CRP and indirect calorimetry results for mice treated with ASP-neutralizing antibody or control antibody. Fasting plasma samples from NI-IgG treated mice (n = 6, white bars) and Anti-ASP treated mice (n = 7, black bars). (A) Polyclonal rabbit antibody detected in mouse plasma following 9 days and 4 weeks treatment. (B) Plasma IL-6 and (C) CRP levels at end of treatment. Results were analyzed by unpaired two-tailed t-test. (D) Energy expenditure measured over 24 hours for NI-IgG treated mice (n = 6, white squares) and Anti-ASP treated mice (n = 7, black squares). Results were analyzed by two-way ANOVA. Group and time P values are reported in graph, their interaction was not significant. Analysis of light and dark periods separately (2-way ANOVA) indicated a significant difference between Anti-ASP and NI-IgG for both time periods (P < 0.0001) (E) Light and dark phase energy expenditure calculated as the area-under the curve (AUC). (F) respiratory quotient (RQ) measured over 24 hours for NI-IgG treated mice (white squares) and Anti-ASP treated mice (black squares). Results were analyzed by two-way ANOVA. Group and time P values are reported in graph, their interaction was not significant. All values are presented as mean ± SEM, where * P < 0.05.
Mentions: Mice were treated by osmotic mini-pump for 4 weeks with neutralizing Anti-ASP or control non-immune IgG (NI-IgG). Plasma samples were taken 9 days after implantation of the osmotic pump and at the end of the study to track the amount of antibody delivered into circulation. Figure 2A shows that on day 9 rabbit NI-IgG and Anti-ASP antibodies were detected (~4% of starting material). However, by the end, the levels of both NI-IgG and Anti-ASP were greatly reduced (~0.1% of starting material). Since there was no difference in osmotic mini-pump rate for PBS, rabbit antibodies or rASP treatments (data not shown), reduced antibody levels may be attributed to enhanced antibody clearance. Anti-ASP blocking antibody treatment had no effect on mouse body weight (NI-IgG: 29.2 ± 0.4 g and Anti-ASP: 29.6 ± 0.3 g, NS, n = 6-7), average food intake (NI-IgG: 13.8 ± 0.5 kcal/day and Anti-ASP: 14.3 ± 0.5 kcal/day, NS, n = 6-7) or food efficiency (NI-IgG: 200.1 ± 21.2 kcal/g and Anti-ASP: 165.6 ± 25.8 kcal/g, NS, n = 6-7), consistent with our previous report during a 10 day study [17]. There was also no difference in adipose tissue depots, liver or spleen weight between the two groups (data not shown). IL-6 levels were slightly but significantly elevated in Anti-ASP mice (P < 0.05, Figure 2B). However, CRP levels, a marker of inflammation, were normal (Figure 2C). Anti-ASP did not have an effect on fasting glucose levels after nine days of treatment (NI-IgG: 6.22 ± 0.62 mmol/L and Anti-ASP: 6.58 ± 0.54 mmol/L, NS, n = 6-7). Furthermore, there was no difference in plasma adiponectin, insulin, C3, or lipid levels between the two groups at the end of the study (Table 1).

Bottom Line: Again, there was no change in circulating insulin, adiponectin, CRP or TG levels, however, plasma free fatty acids were reduced (-48%, P < 0.05).In vitro, Anti-ASP effectively neutralized ASP stimulated fatty acid uptake.Therefore, ASP is a potent anabolic hormone that may also be a mediator of energy expenditure.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, G1V 4G5, Canada.

ABSTRACT

Background: Acylation stimulating protein (ASP) is an adipogenic hormone that stimulates triglyceride (TG) synthesis and glucose transport in adipocytes. Previous studies have shown that ASP-deficient C3 knockout mice are hyperphagic yet lean, as they display increased oxygen consumption and fatty acid oxidation compared to wildtype mice. In the present study, antibodies against ASP (Anti-ASP) and human recombinant ASP (rASP) were tested in vitro and in vivo. Continuous administration for 4 weeks via osmotic mini-pump of Anti-ASP or rASP was evaluated in wildtype mice on a high-fat diet (HFD) to examine their effects on body weight, food intake and energy expenditure.

Results: In mature murine adipocytes, rASP significantly stimulated fatty acid uptake (+243% vs PBS, P < 0.05) while Anti-ASP neutralized the rASP response. Mice treated with Anti-ASP showed elevated energy expenditure (P < 0.0001), increased skeletal muscle glucose oxidation (+141%, P < 0.001), reduced liver glycogen (-34%, P < 0.05) and glucose-6-phosphate content (-64%, P = 0.08) compared to control mice. There was no change in body weight, food intake, fasting insulin, adiponectin, CRP or TG levels compared to controls. Interestingly, HFD mice treated with rASP showed the opposite phenotype with reduced energy expenditure (P < 0.0001) and increased body weight (P < 0.05), cumulative food intake (P < 0.0001) and liver glycogen content (+59%, P < 0.05). Again, there was no change in circulating insulin, adiponectin, CRP or TG levels, however, plasma free fatty acids were reduced (-48%, P < 0.05).

Conclusion: In vitro, Anti-ASP effectively neutralized ASP stimulated fatty acid uptake. In vivo, Anti-ASP treatment increased whole body energy utilization while rASP increased energy storage. Therefore, ASP is a potent anabolic hormone that may also be a mediator of energy expenditure.

Show MeSH
Related in: MedlinePlus