Tfe3 and Tfeb Transcriptionally Regulate Peroxisome Proliferator-Activated Receptor γ2 Expression in Adipocytes and Mediate Adiponectin and Glucose Levels in Mice

ABSTRACT

Members of the MiT transcription factor family are pivotal regulators of several lineage-selective differentiation programs. We show that two of these, Tfeb and Tfe3, control the regulator of adipogenesis, peroxisome proliferator-activated receptor γ2 (Pparγ2). Knockdown of Tfeb or Tfe3 expression during in vitro adipogenesis causes dramatic downregulation of Pparγ2 expression as well as adipogenesis. Additionally, we found that these factors regulate Pparγ2 in mature adipocytes. Next, we demonstrated that Tfeb and Tfe3 act directly by binding to consensus E-boxes within the Pparγ transcriptional regulatory region. This transcriptional control also exists in vivo, as we discovered that wild-type mice in the fed state increased their expression of Tfe3, Tf3b, and Pparγ in white adipose tissue. Furthermore, Tfe3 knockout (Tfe3KO) mice in the fed state failed to upregulate Pparγ and the adiponectin gene, a Pparγ-dependent gene, confirming the in vivo role for Tfe3. Lastly, we found that blood glucose is elevated and serum adiponectin levels are suppressed in the Tfe3KO mice, indicating that the Tfe3/Tfeb/Pparγ2 axis may contribute to whole-body energy balance. Thus, we offer new insights into the upstream regulation of Pparγ by Tfe3/Tf3b and propose that targeting these transcription factors may offer opportunities to complement existing approaches for the treatment of diseases that have dysregulated energy metabolism.

KEYWORDS:

• adipocyte
• transcription
• Tfeb
• Tfe3
• Pparγ
• development
• Tfe3KO mouse

View correction statement:

Erratum for Salma et al., “Tfe3 and Tfeb Transcriptionally Regulate Peroxisome Proliferator-Activated Receptor γ2 Expression in Adipocytes and Mediate Adiponectin and Glucose Levels in Mice”

ACKNOWLEDGMENTS

We thank Eiríkur Steingrímsson, Neal G. Copeland, and Nancy A. Jenkins for the Tfe3KO mice. We thank Eric Campeau for providing all lentivirus vectors used in this study and Carol Dacwag for technical help with tissue ChIPs. We thank members of the Fisher lab, Kyle Nitzsche, and Rajini Mudhasani for critical discussion and comments.

This work was supported by American Heart Association fellowship (AHA) number 0726015T to N.S., partially supported by the PhRMA Foundation and by grant number R01CA163336 from the National Cancer Institute to J.S.S., and supported by funds from the Melanoma Research Alliance, the Dr. Miriam and Sheldon Adelson Medical Research Foundation, the NIH (RO1-AR043369 and R01CA150226), the U.S.-Israel Binational Science Foundation, and the Doris Duke Medical Research Foundation to D.E.F.

ADDENDUM IN PROOF

While this study was in final preparation for publication, Pastore et al. published related findings that Tfe3 regulates whole-body metabolism in cooperation with Tfeb (N. Pastore et al., EMBO Mol Med 9:605–621, 2017, https://doi.org/10.15252/emmm.201607204). In agreement with the findings of Pastore et al., we found that the Tfe3KO mouse is metabolically imbalanced and that Tfeb plays a cooperative role. Nevertheless, the results of Pastore et al. relating to Tfe3KO mouse fat metabolism were not consistent with our results in many important respects. They did not find significant differences in body weight in Tfe3KO mice versus control mice; they found that Tfe3KO mouse fat mass was 50% higher than that in wild-type (WT) mice; they found a significant reduction in liver weight; they did not find significant reduction in AdipoQ levels; and they found significant decreases in blood glucose levels. Regardless, both studies showed the importance of MiT transcription factors in metabolism. In our study we demonstrated that fat metabolism is linked to the MiT factor via direct control of fat master regulator Pparγ2. We predict that a selective fat reduction of Tfeb or Mitf in the Tfe3KO mouse might clarify the individual contribution of this family of transcription factors in whole-body metabolism.