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Biology subjects

Shusta, E. V.

Publications and source records attributed to Shusta, E. V..

5 recordsLinked to original sources

Forward Programming Identifies Inducers of Blood-Brain Barrier Properties in Human Pluripotent Stem Cell-Derived Endothelial Cells

Brain microvascular endothelial cells (BMECs) forming the blood-brain barrier (BBB) maintain brain homeostasis through specialized properties such as tight junctions, efflux transporters, and low levels of transcytosis. However, mechanisms governing induction of BBB properties during development remain poorly understood. We mined single-cell RNA sequencing datasets to identify transcription factors (TFs) critical for BBB development. Forty-four TFs were overexpressed in human pluripotent stem cell-derived endothelial cells cultured in the presence of the Wnt pathway agonist CHIR99021 to identify TFs capable of directing acquisition of BBB properties via forward programming. Individual TFs, including KLF2, KLF4, FOXF1, FOXF2, ZIC2, ZIC3, NR4A1, NR4A2, FOXC1, and FOXQ1, induced distinct BBB-like gene expression patterns. Combinations of these TFs induced many canonical BBB genes, yielding ECs with reduced endocytosis, increased efflux activity, and improved barrier function. The resultant forward programmed CNS-like ECs (fpCECs) offer promising tools for modeling human BBB development and neurovascular disease and for drug screening.

cell biology↗

Activity-dependent regulation of vascular cholesterol metabolism acts as a negative feedback mechanism for neurovascular coupling

Brain function is dependent on a continuous supply of bloodborne oxygen and nutrients. Because neurons require a greater supply of oxygen and nutrients when active, there is increased local blood flow following neuronal activity. The underlying mechanisms of this hyperemia are termed neurovascular coupling (NVC). Many complex processes contribute to NVC, and there is still much unknown about how vascular physiology adapts to changes in neuronal activity and blood flow. Here we show that neuronal activity increases brain endothelial expression of genes related to cholesterol synthesis and uptake in vivo, and that shear stress is sufficient for upregulation of these genes in vitro. We previously found that treatment with PLX5622 induces upregulation of the same cassette of cholesterol-related genes in brain endothelial cells. In the present study, we find that increasing brain endothelial cholesterol synthesis and/or uptake, either with PLX5622 or targeted AAV-mediated expression of LDLR, inhibits brain arteriole dilation in response to capillary K+ stimulation, and this deficit is rescued by cholesterol depletion. Together, these data suggest that neuronal activity regulates brain endothelial cholesterol, which in turn blocks endothelial retrograde signaling and vasodilation, thus acting as a negative feedback mechanism for NVC.

neuroscience↗

Wnt signaling mediates acquisition of blood-brain barrier properties in naïve endothelium derived from human pluripotent stem cells

Endothelial cells (ECs) in the central nervous system (CNS) acquire their specialized blood-brain barrier (BBB) properties in response to extrinsic signals, with Wnt/{beta}-catenin signaling coordinating multiple aspects of this process. Our knowledge of CNS EC development has been advanced largely by animal models, and human pluripotent stem cells (hPSCs) offer the opportunity to examine BBB development in an in vitro human system. Here we show that activation of Wnt signaling in hPSC-derived naive endothelial progenitors, but not in matured ECs, leads to robust acquisition of canonical BBB phenotypes including expression of GLUT-1, increased claudin-5, and decreased PLVAP. RNA-seq revealed a transcriptome profile resembling ECs with CNS-like characteristics, including Wnt-upregulated expression of LEF1, APCDD1, and ZIC3. Together, our work defines effects of Wnt activation in naive ECs and establishes an improved hPSC-based model for interrogation of CNS barriergenesis.

neuroscience↗

Derivation of Isogenic Mesodermal and Ectomesodermal Chondrocytes from Human Induced Pluripotent Stem Cells for Articular Cartilage Regeneration

Generating phenotypic chondrocytes from human pluripotent stem cells through driving developmental lineage-specific differentiation remains to be of great interest in the field of cartilage regeneration. In this study, we derived chondrocytes from human induced pluripotent stem cells (hiPSCs) along the mesodermal or ectomesodermal lineages to prepare isogenic mesodermal cell-derived chondrocytes (MC-Chs) or neural crest cell-derived chondrocytes (NCC-Chs), respectively, and further evaluated differences in their cellular and molecular characteristics and cartilage repair capabilities. Our results showed that both lineage-derived chondrocytes expressed hyaline cartilage-associated markers and were capable of forming hyaline cartilage-like tissue ectopically and at joint defects. Moreover, NCC-Chs showed the absence of markers of hypertrophic chondrocytes and revealed a closer morphological resemblance to articular chondrocytes and a greater capability of producing glycosaminoglycans and collagen type 2 at cartilage defects compared to MC-Chs. It was found that the profile of global transcript expression of NCC-Chs more closely resembled that of native chondrocytes (NCs) than that of MC-Chs. Induced by additional growth factors identified through the analysis of transcriptome comparison to NCs, both MC-Chs and NCC-Chs showed a further increase in the phenotype of hyaline cartilage chondrocytes. Results of this study reveal differences in cellular and molecular characteristics and cartilage repair capabilities between isogenic hiPSC-derived MC-Chs and NCC-Chs and demonstrate that chondrocytes derived from hiPSCs along the ectomesodermal lineage are a potential cell source for articular cartilage regeneration.

developmental biology↗

Human pluripotent stem cell-derived brain pericyte-like cells induce blood-brain barrier properties

Brain pericytes play an important role in the formation and maintenance of the neurovascular unit (NVU), and their dysfunction has been implicated in central nervous system (CNS) disorders. While human pluripotent stem cells (hPSCs) have been used to model other components of the NVU including brain microvascular endothelial cells (BMECs), astrocytes, and neurons, cells having brain pericyte-like phenotypes have not been described. In this study, we generated neural crest stem cells (NCSCs), the embryonic precursor to forebrain pericytes, from human pluripotent stem cells (hPSCs) and subsequently differentiated NCSCs to brain pericyte-like cells. The brain pericyte-like cells expressed marker profiles that closely resembled primary human brain pericytes, and they self-assembled with endothelial cells to support vascular tube formation. Importantly, the brain pericyte-like cells induced blood-brain barrier (BBB) properties in BMECs, including barrier enhancement and reduction of transcytosis. Finally, brain pericyte-like cells were incorporated with iPSC-derived BMECs, astrocytes, and neurons to form an isogenic human NVU model that should prove useful for the study of the BBB in CNS health, disease, and therapy.

neuroscience↗