TF (transcription factor) Prdm16 (positive regulatory domain-containing protein 16) regulates hematopoietic and neuronal stem cell homeostasis, adipose differentiation, and cardiac development. Its ro Show more
TF (transcription factor) Prdm16 (positive regulatory domain-containing protein 16) regulates hematopoietic and neuronal stem cell homeostasis, adipose differentiation, and cardiac development. Its role in the circulatory system extends beyond the heart, as Prdm16 loss in arterial endothelial cells (ECs) impairs arterial reperfusion of ischemic mouse limbs due to endothelial dysfunction, and Zebrafish were used to analyze vascular development, arteriovenous endothelial specification, and the emergence of arteriovenous malformations in the absence or presence of Prdm16 or Notch signaling. Lentiviral-mediated Prdm16 overexpression in human endothelial (progenitor) cells was coupled to qRT-PCR (real-time quantitative polymerase chain reaction), Western blot, and transcriptional profiling to document Prdm16's importance for arterial lineage specification. Coimmunoprecipitation in HEK293 (human embryonic kidney 293) cells was performed to assess physical interaction between Prdm16 and the Notch pathway. Existing mouse and human data sets were reanalyzed to evaluate Prdm16 expression in mammalian arteriovenous malformations. Prdm16 actively promotes arterial EC identity while suppressing venous fate. Like in mice, Prdm16 is expressed by arterial ECs early during vascular development in zebrafish, where it synergistically coordinates arterial development together with canonical notch signaling, as their combined loss in zebrafish leads to arteriovenous malformations. PRDM16's arterializing effect on human ECs is dependent on canonical Notch activity, as it is blunted in the presence of canonical Notch inhibitors and potentiated in the presence of delta-like ligand 4. Mechanistically, Prdm16 does not increase the protein levels of the cleaved intracellular domain of Notch receptors (notch intracellular domain) but rather potentiates the effect of the latter via physical and functional interaction. Prdm16 further finetunes Notch signaling and arterial development by complexing with Hey2 (Hes-related family bHLH TF with YRPW motif 2), the basic helix-loop-helix TF acting downstream of canonical Notch during arterial lineage specification and development. Together, our data demonstrate an intricate interplay between Prdm16 and Notch in ECs and indicate that Prdm16 signaling may constitute a novel therapeutic target for arteriovenous malformations. Show less
Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease for which the genetic contribution is incompletely understood. We conducted a joint analysis of 5,523,934 imputed SNPs in two n Show more
Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease for which the genetic contribution is incompletely understood. We conducted a joint analysis of 5,523,934 imputed SNPs in two newly-genotyped progressive supranuclear palsy cohorts, primarily derived from two clinical trials (Allon davunetide and NNIPPS riluzole trials in PSP) and a previously published genome-wide association study (GWAS), in total comprising 1646 cases and 10,662 controls of European ancestry. We identified 5 associated loci at a genome-wide significance threshold P < 5 × 10 In total, we identified 6 additional significant or suggestive SNP associations with PSP, and discovered genetic overlap with other neurodegenerative diseases. These findings clarify the pathogenesis and genetic architecture of PSP. Show less