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LRP5 regulates human body fat distribution by modulating adipose progenitor biology in a dose- and depot-specific fashion.

Loh NY, Neville MJ, Marinou K, Hardcastle SA, Fielding BA, Duncan EL, McCarthy MI, Tobias JH, Gregson CL, Karpe F, Christodoulides C - Cell Metab. (2015)

Bottom Line: Equivalent knockdown of LRP5 in both progenitor types dose-dependently impaired β-catenin signaling and led to distinct biological outcomes: diminished gluteal and enhanced abdominal adipogenesis.These data highlight how depot differences in WNT/β-catenin pathway activity modulate human fat distribution via effects on adipocyte progenitor biology.They also identify LRP5 as a potential pharmacologic target for the treatment of cardiometabolic disorders.

View Article: PubMed Central - PubMed

Affiliation: Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK.

No MeSH data available.


Related in: MedlinePlus

Effect of LRP5 KD on Canonical and Non-Canonical WNT and Insulin Signaling Pathways in Abdominal and Gluteal SVCs(A) Western blots for pLRP5/6-Ser1490, active β-catenin, pJNK, and pCAMK2A and qRT-PCR analyses of AXIN2 and IL6, in control (shCON) and LRP5-KD (sh400) abdominal and gluteal immortalized SVCs. α-tubulin, total-JNK (tJNK), and total CAMK2A (tCAMK2A) were western blot loading controls. ∗p < 0.05, ∗∗p < 0.01.(B) Representative western blots of shCON and sh400 abdominal and gluteal immortalized SVCs stimulated with 100 nM insulin for indicated duration. ∗non-specific band, used as loading control.(C) INSR mRNA levels in shCON and sh400 abdominal and gluteal immortalized SVCs.(D) Representative western blots of shCON and sh400 abdominal and gluteal primary (1°) SVCs stimulated with 10 nM insulin for indicated duration. ∗non-specific band detected with anti-pIRS1 (Y612) rabbit pAb, ∗∗non-specific band detected with anti-LRP5 rabbit mAb, used as loading controls. Histogram data are means ± SEM. n = 5–7 independent experiments. qRT-PCR data were normalized to 18S. See also Figure S3.
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fig3: Effect of LRP5 KD on Canonical and Non-Canonical WNT and Insulin Signaling Pathways in Abdominal and Gluteal SVCs(A) Western blots for pLRP5/6-Ser1490, active β-catenin, pJNK, and pCAMK2A and qRT-PCR analyses of AXIN2 and IL6, in control (shCON) and LRP5-KD (sh400) abdominal and gluteal immortalized SVCs. α-tubulin, total-JNK (tJNK), and total CAMK2A (tCAMK2A) were western blot loading controls. ∗p < 0.05, ∗∗p < 0.01.(B) Representative western blots of shCON and sh400 abdominal and gluteal immortalized SVCs stimulated with 100 nM insulin for indicated duration. ∗non-specific band, used as loading control.(C) INSR mRNA levels in shCON and sh400 abdominal and gluteal immortalized SVCs.(D) Representative western blots of shCON and sh400 abdominal and gluteal primary (1°) SVCs stimulated with 10 nM insulin for indicated duration. ∗non-specific band detected with anti-pIRS1 (Y612) rabbit pAb, ∗∗non-specific band detected with anti-LRP5 rabbit mAb, used as loading controls. Histogram data are means ± SEM. n = 5–7 independent experiments. qRT-PCR data were normalized to 18S. See also Figure S3.

Mentions: We examined which WNT pathway(s) were responsible for the biological actions of LRP5. LRP5 KD in both abdominal and gluteal cells led to impaired canonical WNT signaling, as determined by decreased active β-catenin and phosphorylated (active) LRP5/6 protein levels and reduced expression of AXIN2, a universal β-catenin target gene (Figures 3A and S3E). Given that β-catenin is generally thought to restrain adipogenesis, these findings are prima facie counterintuitive to the block in differentiation seen in gluteal SVCs. We next examined whether non-canonical WNT pathways were differentially regulated following LRP5 KD in abdominal and gluteal progenitors. However, both PCP and WNT/Ca2+ signaling were modulated in a directionally uniform manner in LRP5-KD cells. Specifically, LRP5 KD using sh400 (i.e., the more efficient shRNA) led to increased JNK phosphorylation and elevated IL6 expression in both abdominal and gluteal SVCs, consistent with PCP pathway activation (Figure 3A). Conversely, the phosphorylated to total CAMK2A ratio was uniformly decreased in abdominal and gluteal LRP5-KD cells (Figures 3A, S3E, and S3F). LRP5 was shown to promote insulin signaling and adipogenesis in 3T3-L1 preadipocytes (Palsgaard et al., 2012). Hence, we asked whether insulin/IGF1 signaling was driving the actions of LRP5 on adipose progenitor biology. As shown in Figures 3B and S3G, however, neither basal nor stimulated phosphorylation of IRS1, AKT, or ERK1/2 following treatment with 100 nM insulin (i.e., the same dose used to induce adipogenesis) were altered with LRP5 KD. Consistent with these data, no baseline change in insulin receptor (INSR) gene expression was detected in response to LRP5 KD in either abdominal or gluteal SVCs (Figures 3C and S3H). We confirmed and extended these findings in LRP5-KD primary SVCs treated with a more physiological insulin dose (10 nM) (Figure 3D).


LRP5 regulates human body fat distribution by modulating adipose progenitor biology in a dose- and depot-specific fashion.

Loh NY, Neville MJ, Marinou K, Hardcastle SA, Fielding BA, Duncan EL, McCarthy MI, Tobias JH, Gregson CL, Karpe F, Christodoulides C - Cell Metab. (2015)

Effect of LRP5 KD on Canonical and Non-Canonical WNT and Insulin Signaling Pathways in Abdominal and Gluteal SVCs(A) Western blots for pLRP5/6-Ser1490, active β-catenin, pJNK, and pCAMK2A and qRT-PCR analyses of AXIN2 and IL6, in control (shCON) and LRP5-KD (sh400) abdominal and gluteal immortalized SVCs. α-tubulin, total-JNK (tJNK), and total CAMK2A (tCAMK2A) were western blot loading controls. ∗p < 0.05, ∗∗p < 0.01.(B) Representative western blots of shCON and sh400 abdominal and gluteal immortalized SVCs stimulated with 100 nM insulin for indicated duration. ∗non-specific band, used as loading control.(C) INSR mRNA levels in shCON and sh400 abdominal and gluteal immortalized SVCs.(D) Representative western blots of shCON and sh400 abdominal and gluteal primary (1°) SVCs stimulated with 10 nM insulin for indicated duration. ∗non-specific band detected with anti-pIRS1 (Y612) rabbit pAb, ∗∗non-specific band detected with anti-LRP5 rabbit mAb, used as loading controls. Histogram data are means ± SEM. n = 5–7 independent experiments. qRT-PCR data were normalized to 18S. See also Figure S3.
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fig3: Effect of LRP5 KD on Canonical and Non-Canonical WNT and Insulin Signaling Pathways in Abdominal and Gluteal SVCs(A) Western blots for pLRP5/6-Ser1490, active β-catenin, pJNK, and pCAMK2A and qRT-PCR analyses of AXIN2 and IL6, in control (shCON) and LRP5-KD (sh400) abdominal and gluteal immortalized SVCs. α-tubulin, total-JNK (tJNK), and total CAMK2A (tCAMK2A) were western blot loading controls. ∗p < 0.05, ∗∗p < 0.01.(B) Representative western blots of shCON and sh400 abdominal and gluteal immortalized SVCs stimulated with 100 nM insulin for indicated duration. ∗non-specific band, used as loading control.(C) INSR mRNA levels in shCON and sh400 abdominal and gluteal immortalized SVCs.(D) Representative western blots of shCON and sh400 abdominal and gluteal primary (1°) SVCs stimulated with 10 nM insulin for indicated duration. ∗non-specific band detected with anti-pIRS1 (Y612) rabbit pAb, ∗∗non-specific band detected with anti-LRP5 rabbit mAb, used as loading controls. Histogram data are means ± SEM. n = 5–7 independent experiments. qRT-PCR data were normalized to 18S. See also Figure S3.
Mentions: We examined which WNT pathway(s) were responsible for the biological actions of LRP5. LRP5 KD in both abdominal and gluteal cells led to impaired canonical WNT signaling, as determined by decreased active β-catenin and phosphorylated (active) LRP5/6 protein levels and reduced expression of AXIN2, a universal β-catenin target gene (Figures 3A and S3E). Given that β-catenin is generally thought to restrain adipogenesis, these findings are prima facie counterintuitive to the block in differentiation seen in gluteal SVCs. We next examined whether non-canonical WNT pathways were differentially regulated following LRP5 KD in abdominal and gluteal progenitors. However, both PCP and WNT/Ca2+ signaling were modulated in a directionally uniform manner in LRP5-KD cells. Specifically, LRP5 KD using sh400 (i.e., the more efficient shRNA) led to increased JNK phosphorylation and elevated IL6 expression in both abdominal and gluteal SVCs, consistent with PCP pathway activation (Figure 3A). Conversely, the phosphorylated to total CAMK2A ratio was uniformly decreased in abdominal and gluteal LRP5-KD cells (Figures 3A, S3E, and S3F). LRP5 was shown to promote insulin signaling and adipogenesis in 3T3-L1 preadipocytes (Palsgaard et al., 2012). Hence, we asked whether insulin/IGF1 signaling was driving the actions of LRP5 on adipose progenitor biology. As shown in Figures 3B and S3G, however, neither basal nor stimulated phosphorylation of IRS1, AKT, or ERK1/2 following treatment with 100 nM insulin (i.e., the same dose used to induce adipogenesis) were altered with LRP5 KD. Consistent with these data, no baseline change in insulin receptor (INSR) gene expression was detected in response to LRP5 KD in either abdominal or gluteal SVCs (Figures 3C and S3H). We confirmed and extended these findings in LRP5-KD primary SVCs treated with a more physiological insulin dose (10 nM) (Figure 3D).

Bottom Line: Equivalent knockdown of LRP5 in both progenitor types dose-dependently impaired β-catenin signaling and led to distinct biological outcomes: diminished gluteal and enhanced abdominal adipogenesis.These data highlight how depot differences in WNT/β-catenin pathway activity modulate human fat distribution via effects on adipocyte progenitor biology.They also identify LRP5 as a potential pharmacologic target for the treatment of cardiometabolic disorders.

View Article: PubMed Central - PubMed

Affiliation: Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK.

No MeSH data available.


Related in: MedlinePlus