Biology subjects

Wingert, R. A.

Publications and source records attributed to Wingert, R. A..

5 recordsLinked to original sources

bioRxiv2024

Emx2 is an essential regulator of ciliated cell development across embryonic tissues

Cilia are hair-like organelles with vital physiological roles, and ciliogenesis defects underlie a range of severe congenital malformations and human diseases. Here, we report that the empty spiracles homeobox gene 2 (emx2) transcription factor is essential for cilia development across multiple embryonic tissues including the ear, neuromasts and Kupffers vesicle (KV), which establishes left/right axial pattern. emx2 deficient embryos manifest altered fluid homeostasis and kidney defects including decreased multiciliated cells (MCCs), revealing that emx2 is essential to properly establish several renal lineages as well. Further, emx2 deficiency disrupted ciliogenesis on renal monociliated cells and MCCs, and led to aberrant basal body positioning in kidney cells. Interestingly, we discovered that emx2 deficiency was associated with reduced expression of key factors which regulate prostaglandin biosynthesis: the transcriptional regulator peroxisome proliferator-activated receptor gamma 1 alpha (ppargc1a) and its downstream target prostaglandin-endoperoxide synthase 1 (ptgs1), which encodes a crucial enzyme for production of the prostanoid ligand prostaglandin E2 (PGE2). Importantly, both ciliogenesis and renal fate changes were rescued when emx2 deficient embryos were provided with PGE2 or transcripts encoding ptgs1 or ppargc1a. Taken together, our findings reveal new essential roles of emx2 in cilia development across several tissues, and identify emx2 as a critical, novel regulator of prostaglandin biosynthesis during renal development and ciliogenesis.

developmental biology↗

bioRxiv2021

Esrrγa regulates nephron development and ciliogenesis by controlling prostaglandin synthesis and cooperation with Ppargc1a

Cilia are essential for the ontogeny and function of many tissues, including the kidney. In mammals, Esrr{gamma} has been previously established as a significant determinant of renal health, with decreased expression linked to age related dysfunction, cyst formation, and kidney disease. Here, we report that the Esrr{gamma} vertebrate ortholog estrogen related receptor gamma a (esrr{gamma}a) is essential for proper cell fate choice within kidney functional units (nephrons) as well as ciliogenesis. Deficiency of esrr{gamma}a resulted in nephrons with alterations in proximodistal segmentation and a decreased multiciliated epithelial cell populace. Surprisingly, esrr{gamma}a deficiency disrupted renal ciliogenesis and caused a similar abrogation within the developing node and otic vesicle--all defects that occurred independently of changes in cell polarity or basal body organization. These phenotypes were consistent with interruptions in prostaglandin signaling, and we found that ciliogenesis was rescued in esrr{gamma}a deficient embryos with exogenous PGE2 or through overexpression of the cyclooxygenase enzyme Ptgs1. Through genetic interaction studies, we found that peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (ppargc1a), which acts upstream of Ptgs1-mediated prostaglandin synthesis, has a synergistic relationship with esrr{gamma}a in the ciliogenic pathway. These data position esrr{gamma}a as a novel link between ciliogenesis and nephrogenesis through regulation of prostaglandin signaling and cooperation with ppargc1a, and highlight esrr{gamma}a as a potential new target for future ciliopathic treatments.

developmental biology↗

bioRxiv2020

osr1 maintains renal progenitors and regulates podocyte development by promoting wnt2ba through antagonism of hand2

Knowledge about the genetic pathways that control renal cell lineage development is essential to better understand the basis of congenital malformations of the kidney and design regenerative medicine therapies. The embryonic zebrafish kidney, or pronephros, contains two nephrons that are conserved with humans. Recently, the transcription factors Osr1 and Hand2 were found to exert antagonistic influences to balance kidney specification (Perens et al., 2016). Here, we performed a forward genetic screen in zebrafish to identify nephrogenesis regulators, where whole genome sequencing of the novel oceanside (ocn) mutant revealed a nonsense mutation in osr1. ocn mutants evince severe pronephros defects including abrogation of podocytes and proximal tubule cells. Our studies reveal that osr1 is not needed to specify renal progenitors, but rather required to maintain their survival. Additionally, osr1 is requisite for expression of the canonical Wnt ligand wnt2ba, where wnt2ba is expressed in the intermediate mesoderm (IM) and later restricts to podocytes. Deficiency of wnt2ba reduced podocyte progenitors, where overexpression of wnt2ba was sufficient to rescue the podocyte lineage as well as osr1 loss of function. Finally, we demonstrate that reciprocal antagonism between osr1 and hand2 mediates podocyte development specifically by controlling wnt2ba expression in the IM. Together, our data show that Osr1 is essential for a sequence of temporal functions that mediate the survival and lineage decisions of IM progenitors, and subsequently the maintenance of podocytes and proximal tubule epithelium in the embryonic nephron.

developmental biology↗

bioRxiv2020

Kctd15 regulates nephron segment development by repressing Tfap2a activity

A functional vertebrate kidney relies on structural units called nephrons, which are epithelial tubules that contain a sequence of segments each expressing a distinct repertoire of solute transporters. To date, the transcriptional codes driving regional specification, solute transporter program activation, and terminal differentiation of segment populations remain poorly understood. We demonstrate for the first time that the KCTD15 paralogs, kctd15a and kctd15b, function in concert to restrict distal early (DE)/thick ascending limb (TAL) segment lineage assignment in the developing zebrafish pronephros by repressing Tfap2a activity. During renal ontogeny, expression of these factors co-localized with tfap2a in distal tubule precursors. kctd15 loss primed nephron cells to adopt distal fates by driving expansions in slc12a1, kcnj1a.1, and stc1 marker expression. These phenotypes were resultant of Tfap2a hyperactivity, where kctd15a/b-deficient embryos exhibited increased abundance of this transcription factor. Interestingly, tfap2a reciprocally promoted kctd15 transcription, unveiling a circuit of autoregulation operating in nephron progenitors. Concomitant kctd15b knockdown with tfap2a overexpression produced genetic synergy and further expanded the DE population. Our study provides strong evidence that a transcription factor-repressor feedback module employs tight regulation of Tfap2a and Kctd15 kinetics to control nephron segment fate choice and differentiation during kidney development.

developmental biology↗

bioRxiv2018

Tfap2a is a novel gatekeeper of differentiation in renal progenitors during kidney development

Renal functional units known as nephrons undergo patterning events during development that create a segmental array of cellular populations with discrete physiological tasks. Knowledge about the terminal differentiation programs of each nephron segment has central importance for understanding kidney disease and to advance regenerative medicine, as mammalian nephrons grown in organoid cultures from pluripotent cells fail to terminally differentiate. Here, from a novel forward genetic screen using zebrafish we report the discovery that transcription factor AP-2 alpha (tfap2a) coordinates a gene regulatory network that controls the progression of nephron distal segment progenitors into the differentiated state. Overexpression of tfap2a rescued differentiation in mutants and caused ectopic expression of distal segment markers in wild-type nephrons, indicating tfap2a is sufficient to instigate the distal segment differentiation program. tfap2a/2b deficiency exacerbated distal nephron segment differentiation defects, revealing functional redundancy where tfap2a has a dominant role upstream of its family member. With further genetic studies, we assembled a blueprint of the tfap2a gene regulatory network during nephrogenesis. We demonstrate that tfap2a acts downstream of Iroquois homeobox 3b, a conserved distal lineage transcription factor. tfap2a controls a circuit consisting of irx1a, tfap2b, and genes encoding solute transporters that dictate the specialized metabolic functions of the distal nephron segments, and we show for the first time that this regulatory node is distinct from the pathway circuits controlling aspects such as apical-basal polarity and ciliogenesis during the differentiation process. Thus, our studies reveal new insights into the genetic control of differentiation, where tfap2a regulates the suite of segment transporter traits. These findings have relevance for understanding renal birth defects, as well as efforts to recapitulate nephrogenesis in vivo to make functional units that can facilitate organoid applications such as drug discovery and regenerative therapies.\n\nSummary StatementHere, we report for the first time that transcription factor AP-2 alpha (tfap2a) controls the progression from nephron progenitor into the fully differentiated state. This fundamentally deepens our knowledge about the genetic control of kidney development.

developmental biology↗