Adipocytes are differentiated by various transcriptional cascades integrated on the master regulator, Pparγ. To discover new genes involved in adipocyte differentiation, preadipocytes were treated with three newly identified pro-adipogenic small molecules and GW7845 (a Pparγ agonist) for 24 hours and transcriptional profiling was analyzed. Four genes, Peroxisome proliferator-activated receptor γ (Pparγ), human complement factor D homolog (Cfd), Chemokine (C-C motif) ligand 9 (Ccl9), and GIPC PDZ Domain Containing Family Member 2 (Gipc2) were induced by at least two different small molecules but not by GW7845. Cfd and Ccl9 expressions were specific to adipocytes and they were altered in obese mice. Small hairpin RNA (shRNA) mediated knockdown of Cfd in preadipocytes inhibited lipid accumulation and expression of adipocyte markers during adipocyte differentiation. Overexpression of Cfd promoted adipocyte differentiation, increased C3a production, and led to induction of C3a receptor (C3aR) target gene expression. Similarly, treatments with C3a or C3aR agonist (C4494) also promoted adipogenesis. C3aR knockdown suppressed adipogenesis and impaired the pro-adipogenic effects of Cfd, further suggesting the necessity for C3aR signaling in Cfd-mediated pro-adipogenic axis. Together, these data show the action of Cfd in adipogenesis and underscore the application of small molecules to identify genes in adipocytes.

Hutchinson-Gilford progeria syndrome (HGPS) is caused by point mutations that increase utilization of an alternate splice donor site in exon 11 of LMNA (the gene encoding lamin C and prelamin A). The alternate splicing reduces transcripts for wild-type prelamin A and increases transcripts for a truncated prelamin A (progerin). Here, we show that antisense oligonucleotides (ASOs) against exon 11 sequences downstream from the exon 11 splice donor site promote alternate splicing in both wild-type and HGPS fibroblasts, increasing the synthesis of progerin. Indeed, wild-type fibroblasts transfected with these ASOs exhibit progerin levels similar to (or greater than) those in fibroblasts from HGPS patients. This progerin was farnesylated, as judged by metabolic labeling studies. The synthesis of progerin in wild-type fibroblasts was accompanied by the same nuclear shape and gene-expression perturbations observed in HGPS fibroblasts. An ASO corresponding to the 5' portion of intron 11 also promoted alternate splicing. In contrast, an ASO against exon 11 sequences 5' to the alternate splice site reduced alternate splicing in HGPS cells and modestly lowered progerin levels. Thus, different ASOs can be used to increase or decrease 'HGPS splicing'. ASOs represent a new and powerful tool for recreating HGPS pathophysiology in wild-type cells.