Project description:Brain pericytes are critical for regulating endothelial barrier function and activity, thus ensuring adequate blood flow to the brain. How the developmental acquisition of pericytes to naked endothelium is regulated, is largely unknown, but is relevant to disorders where vessels are poorly stabilized. Although pericytes are derived from neural crest and mesoderm, brain pericytes from both origins are currently indistinguishable; the genetic pathways leading to a convergent pericyte phenotype are unknown. We show here that a precursor population expressing the transcription factor nkx3.1 with origins in both NCC and mesoderm, develops into brain pericytes. We identify the gene signature of these precursors and show that an nkx3.1, foxf2a, and cxcl12b -expressing pericyte precursor population is present around the cxcr4 expressing basilar artery, and that these cells later spread throughout the brain. Cxcl12b- Cxcr4 signaling is required for pericyte attachment and differentiation but not for later pericyte development. Further, both nkx3.1 and cxcl12b are necessary and sufficient in regulating pericyte number. Thus, we have defined an undescribed population of pericyte precursors and identified genes critical for their differentiation.
Project description:Brain pericytes are critical for regulating endothelial barrier function and activity, thus ensuring adequate blood flow to the brain. How the developmental acquisition of pericytes to naked endothelium is regulated, is largely unknown, but is relevant to disorders where vessels are poorly stabilized. Although pericytes are derived from neural crest and mesoderm, brain pericytes from both origins are currently indistinguishable; the genetic pathways leading to a convergent pericyte phenotype are unknown. We show here that a precursor population expressing the transcription factor nkx3.1 with origins in both NCC and mesoderm, develops into brain pericytes. We identify the gene signature of these precursors and show that an nkx3.1, foxf2a, and cxcl12b -expressing pericyte precursor population is present around the cxcr4 expressing basilar artery, and that these cells later spread throughout the brain. Cxcl12b- Cxcr4 signaling is required for pericyte attachment and differentiation but not for later pericyte development. Further, both nkx3.1 and cxcl12b are necessary and sufficient in regulating pericyte number. Thus, we have defined an undescribed population of pericyte precursors and identified genes critical for their differentiation.
Project description:Bulk RNA-Seq datasets supporting a common precursor expression program leading to brain pericyte differentiation from neural crest and mesoderm
Project description:Brain pericytes are one of the critical cell types that regulate endothelial barrier function and activity, thus ensuring adequate blood flow to the brain. The genetic pathways guiding undifferentiated cells into mature pericytes are not well understood. We show here that pericyte precursor populations from both neural crest and head mesoderm of zebrafish express the transcription factor nkx3.1 develop into brain pericytes. We identify the gene signature of these precursors and show that an nkx3.1-, foxf2a-, and cxcl12b-expressing pericyte precursor population is present around the basilar artery prior to artery formation and pericyte recruitment. The precursors later spread throughout the brain and differentiate to express canonical pericyte markers. Cxcl12b-Cxcr4 signaling is required for pericyte attachment and differentiation. Further, both nkx3.1 and cxcl12b are necessary and sufficient in regulating pericyte number as loss inhibits and gain increases pericyte number. Through genetic experiments, we have defined a precursor population for brain pericytes and identified genes critical for their differentiation. This SuperSeries is composed of the SubSeries listed below.
Project description:Pericytes and endothelial cells (ECs) are building blocks of blood vessels. While the contributions of ECs to tumor angiogenesis and the tumor microenvironment are well established and multiple drugs that targeting ECs have been developed for clinic use to treat cancers, the underlying mechanisms of pericyte in supporting tumor vessel and in shaping tumor microenvironment remains largely unexplored and no pericyte targeting strategies have been approved yet. This study employs targeted deletion of the NO receptor sGC in pericytes and utilizes single-cell RNA sequencing to elucidate its impact on the tumor microenvironment. The results unveil a disruptive effect on EC-pericyte interactions, subsequently impeding Notch-mediated intercellular crosstalk and prompting extensive transcriptomic reprogramming in both cell types. This vascular alteration further relays to neighboring cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) through paracrine signaling, collectively suppressing tumor growth. Importantly, the inhibition of pericyte sGC has limited influence on quiescent vessels but significantly sensitizes angiogenic vessels to anti-angiogenic treatment. In conclusion, this study underscores the vital role of pericytes in governing tumor vessels and the tumor microenvironment, suggesting that targeting pericyte sGC holds promise for enhancing anti-angiogenic therapy.
Project description:Proteomics analysis can reveal the differences of protein expression between mural cells (known as pericytes) from normal adjacent tissues (NPC) and tumors (TPC), implying the effectiveness of pericyte to tumor.
Project description:We report the identification of a cell population that shares pericyte, stromal and stemness features, does not harbour the KrasG12D mutation and drives tumoral growth in vitro and in vivo. We termed these cells pericyte stem cells (PeSCs) and defined them as CD45-EPCAM-CD29+CD106+CD24+CD44+ cells. Our data reveals the existence of a cell population that instruct immunosuppressive myeloid cell responses to bypass PD-1 targeting and thus suggest potential new approaches for overcoming resistance to immunotherapy in clinical settings.
Project description:Background: Pericytes regulate vessel stabilization and function and their loss is associated with diseases such as diabetic retinopathy or cancer. Despite their physiological importance, pericyte function and molecular regulation during angiogenesis remain poorly understood. Methods: To decipher the transcriptomic programs of pericytes during angiogenesis, we crossed the Pdgfrb(BAC)-CreERT2 into the RiboTagflox/flox mice. Pericyte morphological changes were assessed in mural cell-specific R26-mTmG reporter mice, in which low doses of tamoxifen allowed labeling of single cell pericytes at high resolution. To study the role of phosphoinositide 3-kinase (PI3K) signaling in pericyte biology during angiogenesis, we used genetic mouse models which allow selective inactivation of PI3Kα and PI3Kβ isoforms and their negative regulator PTEN (phosphate and tensin homologue deleted on chromosome ten, PTEN) in mural cells. Results: At the onset of angiogenesis, pericytes exhibit molecular traits of cell proliferation and activated PI3K signaling, whereas during vascular remodeling pericytes upregulate genes involved in mature pericyte cell function, together with a remarkable decrease in PI3K signaling. Immature pericytes showed stellate shape and high proliferation, and mature pericytes were quiescent and elongated. Unexpectedly, we demonstrate that the PI3Kβ, but not PI3Kα, regulates pericyte proliferation and maturation during vessel formation. Genetic PI3Kβ inactivation in pericytes triggered early pericyte maturation. Conversely, unleashing PI3K signaling by means of PTEN deletion delayed pericyte maturation. Pericyte maturation was necessary to undergo vessel remodeling during angiogenesis. Conclusions: Our results identify new molecular and morphological traits associated to pericyte maturation and uncover PI3Kβ activity as a checkpoint to ensure appropriate vessel formation. In turn, our results may open new therapeutic opportunities to regulate angiogenesis in pathological processes through the manipulation of pericyte PI3Kβ activity.