Biology subjects

Banks, K. M.

Publications and source records attributed to Banks, K. M..

3 recordsLinked to original sources

bioRxiv2025

GATA6 Mediates Endoderm and Mesoderm Progenitor Fate Driven by WNT and NODAL Signaling

During gastrulation, NODAL and WNT signaling drives distinct gene regulatory networks (GRNs) to promote pluripotency exit, specify progenitor fate, and direct lineage differentiation. Here, we employ murine embryonic stem cell directed differentiation toward endoderm and mesoderm lineages to reveal a crucial role of GATA6 during anterior primitive streak-derived progenitor segregation. GATA6 is known to direct by default extra-embryonic endoderm. To promote definitive endoderm fate, GATA6 reinforces the endoderm GRN driven by NODAL while repressing the mesoderm GRN through down-regulation of WNT activity. During progression of mesoderm differentiation, GATA6 induces a switch in the transcriptional output regulated by WNT, promoting lateral mesoderm specification and repression of paraxial mesoderm fate. Thus, this single transcription factor mediates formation of four distinct tissue types, depending on integration of NODAL/WNT activities. Regulation of Eomes and T/Bra expression during anterior primitive streak progression is an essential function of GATA6 during the specification of endoderm or mesoderm fate.

developmental biology↗

bioRxiv2024

GATA6 regulates WNT and BMP programs to pattern precardiac mesoderm during the earliest stages of human cardiogenesis

Haploinsufficiency for GATA6 is associated with congenital heart disease (CHD) with variable comorbidity of pancreatic or diaphragm defects, although the etiology of disease is not well understood. Here, we used cardiac directed differentiation from human embryonic stem cells (hESCs) as a platform to study GATA6 function during early cardiogenesis. GATA6 loss-of-function hESCs had a profound impairment in cardiac progenitor cell (CPC) specification and cardiomyocyte (CM) generation due to early defects during the mesendoderm and lateral mesoderm patterning stages. Profiling by RNA-seq and CUT&RUN identified genes of the WNT and BMP programs regulated by GATA6 during early mesoderm patterning. Furthermore, interactome analysis detected GATA6 binding with developmental transcription factors and chromatin remodelers suggesting cooperative regulation of cardiac lineage gene accessibility. We show that modulating WNT and BMP inputs during the first 48 hours of cardiac differentiation is sufficient to partially rescue CPC and CM defects in GATA6 heterozygous and homozygous mutant hESCs. This study provides evidence of the regulatory functions for GATA6 directing human precardiac mesoderm patterning during the earliest stages of cardiogenesis to further our understanding of haploinsufficiency causing CHD and the co-occurrence of cardiac and other organ defects caused by human GATA6 mutations.

developmental biology↗

bioRxiv2022

An evolutionarily conserved pacemaker role for HCN ion channels in smooth muscle

Although HCN ion channels are well established to underlie cardiac pacemaker activity, their role in smooth muscle organs remains controversial. HCN expressing cells are localized to renal pelvic smooth muscle (RPSM) pacemaker tissues of the murine upper urinary tract and HCN channel conductance is required for peristalsis. To date, however, the Ih pacemaker current conducted by HCN channels has never been detected in these cells, raising questions on the identity of RPSM pacemakers. Indeed, the RPSM pacemaker mechanisms of the unique multicalyceal upper urinary tract exhibited by humans remains unknown. Here, we developed immunopanning purification protocols and demonstrate that 96% of isolated HCN+ cells exhibit Ih. Single molecule STORM to whole-tissue imaging showed HCN+ cells express single HCN channels on their plasma membrane and integrate into the muscular syncytium. By contrast, PDGFR-+ cells exhibiting the morphology of ICC gut pacemakers were shown to be vascular mural cells. Translational studies in the homologous human and porcine multicalyceal upper urinary tracts showed that contractions and pacemaker depolarizations originate in proximal calyceal RPSM. Critically, HCN+ cells were shown to integrate into calyceal RPSM pacemaker tissues, and HCN channel block abolished electrical pacemaker activity and peristalsis of the multicalyceal upper urinary tract. Cumulatively, these studies demonstrate that HCN ion channels play a broad, evolutionarily conserved pacemaker role in both cardiac and smooth muscle organs and have implications for channelopathies as putative etiologies of smooth muscle disorders.

physiology↗