HAND2 is a novel obesity-linked adipogenic transcription factor regulated by glucocorticoid signalling

• Published in: Diabetologia Vol. 64; no. 8; pp. 1850 - 1865
• Main Authors: Giroud, Maude, Tsokanos, Foivos-Filippos, Caratti, Giorgio, Kotschi, Stefan, Khani, Sajjad, Jouffe, Céline, Vogl, Elena S., Irmler, Martin, Glantschnig, Christina, Gil-Lozano, Manuel, Hass, Daniela, Khan, Asrar Ali, Garcia, Marcos Rios, Mattijssen, Frits, Maida, Adriano, Tews, Daniel, Fischer-Posovszky, Pamela, Feuchtinger, Annette, Virtanen, Kirsi A., Beckers, Johannes, Wabitsch, Martin, Uhlenhaut, Henriette, Blüher, Matthias, Tuckermann, Jan, Scheideler, Marcel, Bartelt, Alexander, Herzig, Stephan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-08-2021; Springer Nature B.V
• Subjects: Adipocytes; Adipocytes - metabolism; Adipogenesis; Adipogenesis - physiology; Adipose tissue; Adipose Tissue, Brown - metabolism; Adult; Aged; Animal models; Animals; Basic Helix-Loop-Helix Transcription Factors - genetics; Clonal deletion; Cross-Sectional Studies; Dexamethasone; Diabetes; DNA microarrays; Energy metabolism; Female; Gene clusters; Gene deletion; Gene Expression Regulation - physiology; Gene Silencing; Glucocorticoids; Glucocorticoids - pharmacology; HAND2 gene; Human Physiology; Humans; Insulin; Insulin resistance; Internal Medicine; Lipolysis; Male; Medicine; Medicine & Public Health; Mesenchymal stem cells; Metabolic Diseases; Metabolism; Mice; Mice, Inbred C57BL; Mice, Knockout; Middle Aged; Molecular modelling; Neural crest; Obesity; Obesity - genetics; Real-Time Polymerase Chain Reaction; Signal Transduction; siRNA; Steroids; Tamoxifen; Transcription factors; Transcription Factors - genetics; Young Adult; Obesity; Dexamethasone; HAND2; hMADS; Glucocorticoid receptor; Adipocytes; Differentiation; Transcription factor; Human adipose tissue; Mesenchymal stem cells
• ISSN: 0012-186X; 1432-0428; 1432-0428
• DOI: 10.1007/s00125-021-05470-y

Aims/hypothesis
Adipocytes are critical cornerstones of energy metabolism. While obesity-induced adipocyte dysfunction is associated with insulin resistance and systemic metabolic disturbances, adipogenesis, the formation of new adipocytes and healthy adipose tissue expansion are associated with metabolic benefits. Understanding the molecular mechanisms governing adipogenesis is of great clinical potential to efficiently restore metabolic health in obesity. Here we investigate the role of heart and neural crest derivatives-expressed 2 (HAND2) in adipogenesis.
Methods
Human white adipose tissue (WAT) was collected from two cross-sectional studies of 318 and 96 individuals. In vitro, for mechanistic experiments we used primary adipocytes from humans and mice as well as human multipotent adipose-derived stem (hMADS) cells. Gene silencing was performed using siRNA or genetic inactivation in primary adipocytes from loxP and or tamoxifen-inducible Cre-ERT2 mouse models with Cre-encoding mRNA or tamoxifen, respectively. Adipogenesis and adipocyte metabolism were measured by Oil Red O staining, quantitative PCR (qPCR), microarray, glucose uptake assay, western blot and lipolysis assay. A combinatorial RNA sequencing (RNAseq) and ChIP qPCR approach was used to identify target genes regulated by HAND2. In vivo, we created a conditional adipocyte
Hand2
deletion mouse model using Cre under control of the
Adipoq
promoter (
Hand2
AdipoqCre
) and performed a large panel of metabolic tests.
Results
We found that HAND2 is an obesity-linked white adipocyte transcription factor regulated by glucocorticoids that was necessary but insufficient for adipocyte differentiation in vitro. In a large cohort of humans, WAT
HAND2
expression was correlated to BMI. The
HAND2
gene was enriched in white adipocytes compared with brown, induced early in differentiation and responded to dexamethasone (DEX), a typical glucocorticoid receptor (GR, encoded by
NR3C1
) agonist. Silencing of
NR3C1
in hMADS cells or deletion of GR in a transgenic conditional mouse model results in diminished
HAND2
expression, establishing that adipocyte HAND2 is regulated by glucocorticoids via GR in vitro and in vivo. Furthermore, we identified gene clusters indirectly regulated by the GR–HAND2 pathway. Interestingly, silencing of
HAND2
impaired adipocyte differentiation in hMADS and primary mouse adipocytes. However, a conditional adipocyte
Hand2
deletion mouse model using Cre under control of the
Adipoq
promoter did not mirror these effects on adipose tissue differentiation, indicating that HAND2 was required at stages prior to
Adipoq
expression.
Conclusions/interpretation
In summary, our study identifies HAND2 as a novel obesity-linked adipocyte transcription factor, highlighting new mechanisms of GR-dependent adipogenesis in humans and mice.
Data availability
Array data have been submitted to the GEO database at NCBI (GSE148699).
Graphical abstract