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Inhibition of dipeptidyl peptidase 8/9 impairs preadipocyte differentiation.

Han R, Wang X, Bachovchin W, Zukowska Z, Osborn JW - Sci Rep (2015)

Bottom Line: Here we demonstrate that the DPP8/9 selective inhibitor 1G244 blocks adipogenesis in preadipocyte 3T3-L1 and 3T3-F422A, while DPP4 and FAP inhibitors have no effect.In addition, knockdown of DPP8 or DPP9 significantly impairs adipocyte differentiation in preadipocytes.These results indicate the importance of DPP8 and DPP9 on adipogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA.

ABSTRACT
Adipocytes are the primary cells in adipose tissue, and adipocyte dysfunction causes lipodystrophy, obesity and diabetes. The dipeptidyl peptidase (DPP) 4 family includes four enzymes, DPP4, DPP8, DPP9 and fibroblast activation protein (FAP). DPP4 family inhibitors have been used for the treatment of type 2 diabetes patients, but their role in adipocyte formation are poorly understood. Here we demonstrate that the DPP8/9 selective inhibitor 1G244 blocks adipogenesis in preadipocyte 3T3-L1 and 3T3-F422A, while DPP4 and FAP inhibitors have no effect. In addition, knockdown of DPP8 or DPP9 significantly impairs adipocyte differentiation in preadipocytes. We further uncovered that blocking the expression or activities of DPP8 and DPP9 attenuates PPARγ2 induction during preadipocyte differentiation. Addition of PPARγ agonist thiazolidinediones (TZDs), or ectopic expression of PPARγ2, is able to rescue the adipogenic defect caused by DPP8/9 inhibition in preadipocytes. These results indicate the importance of DPP8 and DPP9 on adipogenesis.

No MeSH data available.


Related in: MedlinePlus

Inhibition of DPP8 and DPP9 prevents PPARγ2 induction during 3T3-L1 differentiation.(A) PPARγ2, CEBPα, CEBPβ and CEBPδ mRNA levels were measured in control-shRNA-transduced 3T3-L1 cells (shCTL) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) at basal level. (B) PPARγ2 and CEBPα mRNA levels were measured in control-shRNA-transduced cells (shCTL.) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) after 48 hour treatment of DMI. CEBPβ and CEBPδ mRNA levels were measured after 6 hour treatment. (C) PPARγ2 and CEBPα mRNA levels were measured after 48 hour treatment of dexamethasone, isobutylmethylxanthine and insulin (DMI) with or without the DPP4 inhibitor MK-0431(DMI+MK-0431), the DPP8/9 inhibitor 1G244 (DMI+1G244), the FAP inhibitor 3099 (DMI+3099). CEBPβ and CEBPδ mRNA levels were measured in these cells after 6 hour treatment.
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f4: Inhibition of DPP8 and DPP9 prevents PPARγ2 induction during 3T3-L1 differentiation.(A) PPARγ2, CEBPα, CEBPβ and CEBPδ mRNA levels were measured in control-shRNA-transduced 3T3-L1 cells (shCTL) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) at basal level. (B) PPARγ2 and CEBPα mRNA levels were measured in control-shRNA-transduced cells (shCTL.) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) after 48 hour treatment of DMI. CEBPβ and CEBPδ mRNA levels were measured after 6 hour treatment. (C) PPARγ2 and CEBPα mRNA levels were measured after 48 hour treatment of dexamethasone, isobutylmethylxanthine and insulin (DMI) with or without the DPP4 inhibitor MK-0431(DMI+MK-0431), the DPP8/9 inhibitor 1G244 (DMI+1G244), the FAP inhibitor 3099 (DMI+3099). CEBPβ and CEBPδ mRNA levels were measured in these cells after 6 hour treatment.

Mentions: Next we sought to elucidate the mechanism of action of DPP8/9 in preadipocyte differentiation. PPARγ is the master regulator of adipocyte differentiation. Activation of PPARγ at an early stage is necessary and sufficient for adipogenesis4. We hypothesized that the effect of DPP8/9 inhibitor on adipogenesis was mediated by PPARγ. The expression PPARγ2 was significantly decreased in stable 3T3-L1 cell expressing shRNA sequences targeting both DPP8 and DPP9, compared to those expressing a control shRNA at basal level with no differentiation cocktail (DMI) (Fig. 4A). When treated with a differentiation cocktail DMI, PPARγ2 was markedly increased after 48 hours in 3T3-L1 cells (Fig. 4B). DMI induced expression of PPARγ2 was partly blocked with depletion of either DPP8 or DPP9. Since PPARγ gene is regulated by CEBPs4, we determined the effect of DPP8 or DPP9 depletion on the expression of CEBPα, CEBPβ and CEBPδ. We found that depletion of DPP8 or DPP9 also attenuated basal and DMI-induced CEBPα mRNA levels (Fig. 4A,B) but had no effect on expression of CEBPβ and CEBPδ (Fig. 4A,B). Knockdown of both DPP8 and DPP9 completely blocked the DMI induced expression of PPARγ2 and CEBPα (Fig. 4B) in 3T3-L1. In addition, the DPP8/9 inhibitor 1G244 attenuated DMI-induced PPARγ2 and CEBPα mRNA (Fig. 4C), but had no effect on the expression of CEBPβ and CEBPδ (Fig. 4C). On the other hand, DPP4 inhibitor MK-0431 and FAP inhibitor 3099 had no effect on DMI induced expression of CEBPα, CEBPβ, CEBPδ and PPARγ2 during 3T3-L1 differentiation (Fig. 4C).


Inhibition of dipeptidyl peptidase 8/9 impairs preadipocyte differentiation.

Han R, Wang X, Bachovchin W, Zukowska Z, Osborn JW - Sci Rep (2015)

Inhibition of DPP8 and DPP9 prevents PPARγ2 induction during 3T3-L1 differentiation.(A) PPARγ2, CEBPα, CEBPβ and CEBPδ mRNA levels were measured in control-shRNA-transduced 3T3-L1 cells (shCTL) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) at basal level. (B) PPARγ2 and CEBPα mRNA levels were measured in control-shRNA-transduced cells (shCTL.) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) after 48 hour treatment of DMI. CEBPβ and CEBPδ mRNA levels were measured after 6 hour treatment. (C) PPARγ2 and CEBPα mRNA levels were measured after 48 hour treatment of dexamethasone, isobutylmethylxanthine and insulin (DMI) with or without the DPP4 inhibitor MK-0431(DMI+MK-0431), the DPP8/9 inhibitor 1G244 (DMI+1G244), the FAP inhibitor 3099 (DMI+3099). CEBPβ and CEBPδ mRNA levels were measured in these cells after 6 hour treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4525143&req=5

f4: Inhibition of DPP8 and DPP9 prevents PPARγ2 induction during 3T3-L1 differentiation.(A) PPARγ2, CEBPα, CEBPβ and CEBPδ mRNA levels were measured in control-shRNA-transduced 3T3-L1 cells (shCTL) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) at basal level. (B) PPARγ2 and CEBPα mRNA levels were measured in control-shRNA-transduced cells (shCTL.) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) after 48 hour treatment of DMI. CEBPβ and CEBPδ mRNA levels were measured after 6 hour treatment. (C) PPARγ2 and CEBPα mRNA levels were measured after 48 hour treatment of dexamethasone, isobutylmethylxanthine and insulin (DMI) with or without the DPP4 inhibitor MK-0431(DMI+MK-0431), the DPP8/9 inhibitor 1G244 (DMI+1G244), the FAP inhibitor 3099 (DMI+3099). CEBPβ and CEBPδ mRNA levels were measured in these cells after 6 hour treatment.
Mentions: Next we sought to elucidate the mechanism of action of DPP8/9 in preadipocyte differentiation. PPARγ is the master regulator of adipocyte differentiation. Activation of PPARγ at an early stage is necessary and sufficient for adipogenesis4. We hypothesized that the effect of DPP8/9 inhibitor on adipogenesis was mediated by PPARγ. The expression PPARγ2 was significantly decreased in stable 3T3-L1 cell expressing shRNA sequences targeting both DPP8 and DPP9, compared to those expressing a control shRNA at basal level with no differentiation cocktail (DMI) (Fig. 4A). When treated with a differentiation cocktail DMI, PPARγ2 was markedly increased after 48 hours in 3T3-L1 cells (Fig. 4B). DMI induced expression of PPARγ2 was partly blocked with depletion of either DPP8 or DPP9. Since PPARγ gene is regulated by CEBPs4, we determined the effect of DPP8 or DPP9 depletion on the expression of CEBPα, CEBPβ and CEBPδ. We found that depletion of DPP8 or DPP9 also attenuated basal and DMI-induced CEBPα mRNA levels (Fig. 4A,B) but had no effect on expression of CEBPβ and CEBPδ (Fig. 4A,B). Knockdown of both DPP8 and DPP9 completely blocked the DMI induced expression of PPARγ2 and CEBPα (Fig. 4B) in 3T3-L1. In addition, the DPP8/9 inhibitor 1G244 attenuated DMI-induced PPARγ2 and CEBPα mRNA (Fig. 4C), but had no effect on the expression of CEBPβ and CEBPδ (Fig. 4C). On the other hand, DPP4 inhibitor MK-0431 and FAP inhibitor 3099 had no effect on DMI induced expression of CEBPα, CEBPβ, CEBPδ and PPARγ2 during 3T3-L1 differentiation (Fig. 4C).

Bottom Line: Here we demonstrate that the DPP8/9 selective inhibitor 1G244 blocks adipogenesis in preadipocyte 3T3-L1 and 3T3-F422A, while DPP4 and FAP inhibitors have no effect.In addition, knockdown of DPP8 or DPP9 significantly impairs adipocyte differentiation in preadipocytes.These results indicate the importance of DPP8 and DPP9 on adipogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA.

ABSTRACT
Adipocytes are the primary cells in adipose tissue, and adipocyte dysfunction causes lipodystrophy, obesity and diabetes. The dipeptidyl peptidase (DPP) 4 family includes four enzymes, DPP4, DPP8, DPP9 and fibroblast activation protein (FAP). DPP4 family inhibitors have been used for the treatment of type 2 diabetes patients, but their role in adipocyte formation are poorly understood. Here we demonstrate that the DPP8/9 selective inhibitor 1G244 blocks adipogenesis in preadipocyte 3T3-L1 and 3T3-F422A, while DPP4 and FAP inhibitors have no effect. In addition, knockdown of DPP8 or DPP9 significantly impairs adipocyte differentiation in preadipocytes. We further uncovered that blocking the expression or activities of DPP8 and DPP9 attenuates PPARγ2 induction during preadipocyte differentiation. Addition of PPARγ agonist thiazolidinediones (TZDs), or ectopic expression of PPARγ2, is able to rescue the adipogenic defect caused by DPP8/9 inhibition in preadipocytes. These results indicate the importance of DPP8 and DPP9 on adipogenesis.

No MeSH data available.


Related in: MedlinePlus