Biology subjects

Hukriede, N. A.

Publications and source records attributed to Hukriede, N. A..

3 recordsLinked to original sources

bioRxiv2023

Genetically engineering endothelial niche in human kidney organoids enables multilineage maturation, vascularization, and de novo cell types

Vascularization plays a critical role in organ maturation and cell type development. Drug discovery, organ mimicry, and ultimately transplantation in a clinical setting thereby hinges on achieving robust vascularization of in vitro engineered organs. Here, focusing on human kidney organoids, we overcome this hurdle by combining an inducible ETS translocation variant 2 (ETV2) human induced pluripotent stem cell (iPSC) line, which directs endothelial fate, with a non-transgenic iPSC line in suspension organoid culture. The resulting human kidney organoids show extensive vascularization by endothelial cells with an identity most closely related to endogenous kidney endothelia. Vascularized organoids also show increased maturation of nephron structures including more mature podocytes with improved marker expression, foot process interdigitation, an associated fenestrated endothelium, and the presence of renin+ cells. The creation of an engineered vascular niche capable of improving kidney organoid maturation and cell type complexity is a significant step forward in the path to clinical translation. Furthermore, this approach is orthogonal to native tissue differentiation paths, hence readily adaptable to other organoid systems and thus has the potential for a broad impact on basic and translational organoid studies. Translational StatementDeveloping therapies for patients with kidney diseases relies on a morphologically and physiologically representative in vitro model. Human kidney organoids are an attractive model to recapitulate kidney physiology, however, they are limited by the absence of a vascular network and mature cell populations. In this work, we have generated a genetically inducible endothelial niche that, when combined with an established kidney organoid protocol, induces the maturation of a robust endothelial cell network, induces a more mature podocyte population, and induces the emergence a functional renin population. This advance significantly increases the clinical relevance of human kidney organoids for etiological studies of kidney disease and future regenerative medicine strategies. Graphical AbstractGenetically engineered endothelial niche induces mature cell populations in human kidney organoids O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=100 SRC="FIGDIR/small/542848v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1b129d4org.highwire.dtl.DTLVardef@313ae3org.highwire.dtl.DTLVardef@111c91org.highwire.dtl.DTLVardef@16a8d45_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2023

Xenopus Ssbp2 is required for embryonic pronephros morphogenesis and terminal differentiation

The nephron, functional unit of the vertebrate kidney, is specialized in metabolic wastes excretion and body fluids osmoregulation. Given the high evolutionary conservation of gene expression and segmentation patterning between mammalian and amphibian nephrons, the Xenopus laevis pronephric kidney offers a simplified model for studying nephrogenesis. The Lhx1 transcription factor plays several roles during embryogenesis, regulating target genes expression by forming multiprotein complexes with LIM binding protein 1 (Ldb1). However, few Lhx1-Ldb1 cofactors have been identified for kidney organogenesis. By tandem-affinity purification from kidney-induced Xenopus animal caps, we identified single-stranded DNA binding protein 2 (Ssbp2) interacts with the Ldb1-Lhx1 complex. Ssbp2 is expressed in the Xenopus pronephros, and knockdown prevents normal morphogenesis and differentiation of the glomus and the convoluted renal tubules. We demonstrate a role for a member of the Ssbp family in kidney organogenesis and provide evidence of a fundamental function for the Ldb1-Lhx1-Ssbp transcriptional complexes in embryonic development.

developmental biology↗

bioRxiv2018

Enhancing acute kidney injury regeneration by promoting cellular dedifferentiation in zebrafish

Acute kidney injury (AKI) is a serious disorder for which there is no approved pharmaceutical treatment. Following injury, native nephrons display limited regenerative capabilities, relying on the dedifferentiation and proliferation of renal tubular epithelial cells (RTECs) that survive the insult. Previously, we identified 4-(phenylthio)butanoic acid (PTBA), a histone deacetylase inhibitor (HDI) that enhances renal recovery and showed that PTBA treatment increased RTEC proliferation and reduced renal fibrosis. Here, we investigated the regenerative mechanisms of PTBA in zebrafish models of larval renal injury and adult cardiac injury. With respect to renal injury, we showed that delivery of PTBA using an esterified prodrug (UPHD25) increases the reactivation of the renal progenitor gene Pax2a, enhances dedifferentiation of RTECs, reduces Kidney injury molecule-1 expression, and lowers the number of infiltrating macrophages. Further, we find that the effects of PTBA on RTEC proliferation depend upon retinoic acid signaling and demonstrate the therapeutic properties of PTBA are not restricted to the kidney but also increase cardiomyocyte proliferation and decrease fibrosis following cardiac injury in adult zebrafish. These studies provide key mechanistic insights into how PTBA enhances tissue repair in models of acute injury and lay the groundwork for translating this novel HDI into the clinic.\n\nSUMMARY STATEMENTMortality associated with acute kidney injury (AKI) is in part due to limited treatments available to ameliorate kidney injury. We identified a compound that enhances AKI recovery by promoting cellular dedifferentiation.

pharmacology and toxicology↗