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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

Knockdown of DPP8 and DPP9 blocked adipocyte differentiation.(A) Gene expression analysis of DPP8 and DPP9 during 3T3L1 differentiation. 3T3L1 cells were cultured in 10% FBS (NC) or treated with dexamethasone, isobutylmethylxanthine and insulin (DMI) from day 0 to day 2 of differentiation, mRNA levels of DPP8 and DPP9 were measured by real time PCR. β-actin expression was used as an internal control. (B) Oil Red O staining of control-shRNA-transduced cells (shCTL) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) at day 8 of differentiation. (C) Adipocyte markers, FABP4, adiponectin (AdipoQ) and leptin, were measured by real time PCR at day 8 of differentiation. β-actin expression was used as an internal control.
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f3: Knockdown of DPP8 and DPP9 blocked adipocyte differentiation.(A) Gene expression analysis of DPP8 and DPP9 during 3T3L1 differentiation. 3T3L1 cells were cultured in 10% FBS (NC) or treated with dexamethasone, isobutylmethylxanthine and insulin (DMI) from day 0 to day 2 of differentiation, mRNA levels of DPP8 and DPP9 were measured by real time PCR. β-actin expression was used as an internal control. (B) Oil Red O staining of control-shRNA-transduced cells (shCTL) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) at day 8 of differentiation. (C) Adipocyte markers, FABP4, adiponectin (AdipoQ) and leptin, were measured by real time PCR at day 8 of differentiation. β-actin expression was used as an internal control.

Mentions: We next assessed the gene expression and enzyme activity of DPPs during adipocyte differentiation. The mRNA level of DPP4 and FAP were low after 48 hours of DMI treatment, whereas the DPP8 and DPP9 mRNA levels were much higher (supplementary Fig. 2A). Evidence suggest that majority of the DPPs activity during differentiation is through DPP8/9 as the DPP8/9 inhibitor 1G244 blocked 82% of total DPPs activity in 3T3-L1 cells; while MK-0431 blocked only 15% and 3099 blocked 20%, respectively (supplementary Fig. 2B). We tested whether DPP8/9 was a regulated component of the differentiation program and if its expression changed over the course of differentiation. Indeed, analysis of a time course of 3T3-L1 cell differentiation revealed that DPP8/9 mRNA expression was significantly increased during DMI treatment (Fig. 3A). Conversely, DPP4 and FAP mRNA expression were decreased (supplementary Fig. 3).


Inhibition of dipeptidyl peptidase 8/9 impairs preadipocyte differentiation.

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

Knockdown of DPP8 and DPP9 blocked adipocyte differentiation.(A) Gene expression analysis of DPP8 and DPP9 during 3T3L1 differentiation. 3T3L1 cells were cultured in 10% FBS (NC) or treated with dexamethasone, isobutylmethylxanthine and insulin (DMI) from day 0 to day 2 of differentiation, mRNA levels of DPP8 and DPP9 were measured by real time PCR. β-actin expression was used as an internal control. (B) Oil Red O staining of control-shRNA-transduced cells (shCTL) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) at day 8 of differentiation. (C) Adipocyte markers, FABP4, adiponectin (AdipoQ) and leptin, were measured by real time PCR at day 8 of differentiation. β-actin expression was used as an internal control.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f3: Knockdown of DPP8 and DPP9 blocked adipocyte differentiation.(A) Gene expression analysis of DPP8 and DPP9 during 3T3L1 differentiation. 3T3L1 cells were cultured in 10% FBS (NC) or treated with dexamethasone, isobutylmethylxanthine and insulin (DMI) from day 0 to day 2 of differentiation, mRNA levels of DPP8 and DPP9 were measured by real time PCR. β-actin expression was used as an internal control. (B) Oil Red O staining of control-shRNA-transduced cells (shCTL) and cells with DPP8/9 shRNAs (shDPP8, shDPP9) at day 8 of differentiation. (C) Adipocyte markers, FABP4, adiponectin (AdipoQ) and leptin, were measured by real time PCR at day 8 of differentiation. β-actin expression was used as an internal control.
Mentions: We next assessed the gene expression and enzyme activity of DPPs during adipocyte differentiation. The mRNA level of DPP4 and FAP were low after 48 hours of DMI treatment, whereas the DPP8 and DPP9 mRNA levels were much higher (supplementary Fig. 2A). Evidence suggest that majority of the DPPs activity during differentiation is through DPP8/9 as the DPP8/9 inhibitor 1G244 blocked 82% of total DPPs activity in 3T3-L1 cells; while MK-0431 blocked only 15% and 3099 blocked 20%, respectively (supplementary Fig. 2B). We tested whether DPP8/9 was a regulated component of the differentiation program and if its expression changed over the course of differentiation. Indeed, analysis of a time course of 3T3-L1 cell differentiation revealed that DPP8/9 mRNA expression was significantly increased during DMI treatment (Fig. 3A). Conversely, DPP4 and FAP mRNA expression were decreased (supplementary Fig. 3).

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