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Arterial development is critical for proper blood flow, but the mechanisms mediating this process at the organ level remain unclear. Here, they show that a subpopulation of endothelial cells is important for formation of arterial endothelium in the intestine.

The role of vascular plasticity in brain function remains poorly understood. Here, the authors demonstrate that a significant portion of blood vessels in the adult brain periodically occlude and regress, a process that is associated with a reduction in neuronal activity.

Bone homeostasis and repair declines with ageing and the mechanisms regulating the relationship between bone growth and blood vessel formation have remained unknown; this mouse study identifies the endothelial cells that promote the formation of new bone, a small microvessel subtype that can be identified by high CD31 and high Emcn expression.

Here they show that ELMO2 is crucial for vascular development, with knockout mice being nonviable due to carotid artery aneurysms. ELMO2 regulates vascular smooth muscle cell behavior, offering insights into VMOS disease and potential treatment strategies.

Three-dimensional analysis of the intact bone marrow within whole long bones remains very challenging. Here, the authors present a method that stabilizes the marrow and provides subcellular resolution of fluorescent signals throughout the murine femur.

Notch signalling in endothelial cells of the bone induces change in the capillaries and mesenchymal stem cells of the environment to support haematopoietic stem cell amplification.

The Akt pathway integrates multiple signals, but whether it affects vasculature function is debatable. Here the authors show that Akt pathway shutdown in adult mouse endothelium causes destabilization of vasculature leading to cardiac and retinal dysfunction, due to decreased levels of Jagged1 and impaired Notch signaling.

Obesity leads to pathological expansion of white adipose tissue driving vascular dysfunction. Here, the authors utilize single-cell RNA sequencing to elucidate endothelial heterogeneity and demarcate key differences in obesity-associated vascular alterations in subcutaneous and visceral white adipose tissue.

Myocardin-related transcription factors (MRTFs) increase muscle growth and regeneration. Here, Hinkel et al. show that MRTFs also promote microvessel growth and maturation in chronic ischaemic disease of the heart or peripheral muscle by increasing the expression of the pro-angiongenic factors, CCN1 and CCN2.

Blood vessel growth in bone is revealed to require Notch signalling and involve a specialized form of angiogenesis that does not involve endothelial sprouts.

Mohanakrishnan et al. identify a distinct subset of post-arterial capillaries, termed type R. They show that type R capillaries contribute to trabecular bone formation in the diaphysis and respond to anti-osteoporosis treatments.

The formation of new blood vessels requires both polarized cell migration and coordinated control of endothelial cell contacts. Here, Cao and colleagues describe at the sub-cellular level the cytoskeletal and cell junction dynamics regulating these processes upon VEGF-induced cell elongation.

Skull bone marrow expands during adult life, exhibits lifelong vascular growth and increases its haematopoietic potential during ageing.

Arteries are vital blood vessels for our body and their growth and patterning are critical for proper blood flow. Here they use a retina model to show that a balance of EphB4 receptor and ephrin-B2 ligand integrate a well-wired molecular network to control arteriovenous patterning and vascular growth.

Fractured long bones regenerate through osteo-angiogenic coupling, but how calvarial bone healing occurs is not yet clear. Here they show that regenerating blood vessels separate from co-migrating progenitors in calvarial bones, resulting in osteoblasts mineralizing a previously vascularized lesion.

Sivaraj, Majev et al. demonstrate that the inactivation of Lats2 in endothelial cells triggers the upregulation of serum response factor and endothelial-to-mesenchymal transition, leading to myofibroblast formation, bone marrow fibrosis, osteosclerosis, impaired bone marrow function and extramedullary hematopoiesis.

Han et al. report the existence of neural stem cells (NSCs) outside the central nervous system and show that these peripheral NSCs display features similar to brain NSCs, including the ability to differentiate into mature neurons.

Pericytes and vascular smooth muscle cells are crucial for functional blood vessels, but the developmental sources of these cells are incompletely understood. Here, the authors show that endocardial endothelial cells give rise to cardiac mural cells, which are controlled by Wnt signalling.

The sprouting activity of filopodia emerging from endothelial sprouting cells needs to be compensated for in mature stable vessels. Adams and colleagues find that sprouting cells in mouse retinal vasculature show high VEGF uptake and VEGF receptor turnover, both essential for sprouting. These are inhibited by an aPKC-mediated decrease in VEGF receptor endocytosis in mature vessels, through a mechanism implicating clathrin-associated proteins, the transmembrane protein ephrin-B2 and the polarity factor PAR-3.

Developmental and regenerative bone formation require the removal of chondrocytes and matrix. Here the authors show that these processes involve mesenchymal stromal cell-derived septoclasts, which disappear after the completion of development but re-emerge during fracture healing.

Formation of new blood vessels and bone is coupled. Here the authors show that blood flow represents a key regulator of angiogenesis and endothelial Notch signalling in the bone, and that reactivation of Notch signalling in the endothelium of aged mice rejuvenates the bone.

The colonization of bone marrow by haematopoietic stem and progenitor cells is critical for lifelong blood cell formation. Here the authors report distinct features of fetal bone marrow and show that artery-derived signals promote haematopoietic colonization.

Pericytes are perivascular cells essential for blood-brain barrier maintenance. Here Diéguez-Hurtado et al. show that depletion of the transcription factor RBPJ in pericytes affects their molecular identity and disturbs endothelial cell behaviour, inducing the formation of vascular lesions in the brain.

Pericytes surround endothelial tubules and help maintain the integrity of blood vessels. Here the authors show that pericytes regulate lung morphogenesis via paracrine signalling controlled by components of the Hippo pathway.

The authors present SVclone, a computational method for inferring the cancer cell fraction of structural variants from whole-genome sequencing data.

Angiogenesis is a complex process that requires coordinated changes in endothelial cell behavior. Here the authors use Ribo-tag and RNA-Seq to determine temporal profiles of transcriptional activity during postnatal retinal angiogenesis, identifying transcriptional regulators of the process.

Pericytes are essential for the development, maintenance and function of vascular networks. Here, Eilken and colleagues show that expression of the decoy receptor VEGFR1 by pericytes spatially restricts VEGF signalling, thus regulating VEGF-induced endothelial cell sprouting in developing tissues.

Integrin-linked kinase (ILK) is an important mediator of integrin signaling. Here Park et al. show that mice with endothelial-specific deletion of Ilk develop vascular defects that resemble familial exudative vitreoretinopathy, and identify mutations in ILK in patients with exudative vitreoretinopathy suggesting a potential role in human pathogenesis.

Apelin is a G protein-coupled receptor ligand that is proteolytically converted into a 13-aa active peptide (A13) involved in a number of physiological processes, including inflammation. Here, the authors demonstrate that A13 reduces the severity of experimental autoimmune encephalitis by modulating leukocyte trafficking and inflammation.

Pitulescu et al. and Hasan et al. show that Dll4–Notch signalling in endothelial tip cells regulates angiogenesis through control of artery formation, linking sprouting angiogenesis and artery formation.

Whole-genome sequencing data for 2,778 cancer samples from 2,658 unique donors across 38 cancer types is used to reconstruct the evolutionary history of cancer, revealing that driver mutations can precede diagnosis by several years to decades.

Cancers evolve as they progress under differing selective pressures. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, the authors present the method TrackSig the estimates evolutionary trajectories of somatic mutational processes from single bulk tumour data.

The role of integrin β1 in angiogenesis is poorly understood. Here, the authors show that integrin β1 regulates murine angiogenesis and adherens junction integrity by controlling VE-cadherin localization, myosin light chain phosphorylation and the function of the Rap1/MRCK and Rho/Rho-kinase pathways.

Langen et al. identify a third capillary endothelial cell subtype, termed type E, that supports embryonic and early postnatal bone formation, and show that endothelial integrin β1 and laminin α5 are required for bone angiogenesis and osteogenesis.

Analyses of 2,658 whole genomes across 38 types of cancer identify the contribution of non-coding point mutations and structural variants to driving cancer.

Steve Brown and colleagues report an analysis of 20 phenotyping tests, including 413 data parameters, across 449 mutant mouse alleles. They identify widespread pleiotropy and assign putative functions to genes that lacked previous phenotypic annotation.

Bone marrow endothelial cells have dual roles in the regulation of haematopoietic stem cell maintenance and in the trafficking of blood cells between the bone marrow and the blood circulatory system; this study shows that these different functions are regulated by distinct types of endothelial blood vessels with different permeability properties, affecting the metabolic state of their neighbouring stem cells.

Integrative analyses of transcriptome and whole-genome sequencing data for 1,188 tumours across 27 types of cancer are used to provide a comprehensive catalogue of RNA-level alterations in cancer.

With the generation of large pan-cancer whole-exome and whole-genome sequencing projects, a question remains about how comparable these datasets are. Here, using The Cancer Genome Atlas samples analysed as part of the Pan-Cancer Analysis of Whole Genomes project, the authors explore the concordance of mutations called by whole exome sequencing and whole genome sequencing techniques.

The characterization of 4,645 whole-genome and 19,184 exome sequences, covering most types of cancer, identifies 81 single-base substitution, doublet-base substitution and small-insertion-and-deletion mutational signatures, providing a systematic overview of the mutational processes that contribute to cancer development.

The protein ephrin-B2 is known to be upregulated during angiogenesis — the growth of new blood vessels — but its precise function has been unclear. Here it is shown that signalling through ephrin-B2 controls vessel sprouting. Mechanistically, ephrin-B2 seems to function in part by regulating the internalization of vascular endothelial growth factor receptors (VEGFRs). The results indicate that blocking ephrin-B2 signalling might be an alternative to blocking VEGFR function to disrupt angiogenesis in tumours.

The flagship paper of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes Consortium describes the generation of the integrative analyses of 2,658 cancer whole genomes and their matching normal tissues across 38 tumour types, the structures for international data sharing and standardized analyses, and the main scientific findings from across the consortium studies.

An analysis of 2,954 genomes from 38 cancer subtypes identified 19,166 retrotransposition events in 35% of samples. Aberrant LINE-1 retrotranspositions can lead to the deletion of tumor-suppressor genes as well as the amplification of oncogenes.

Many tumours exhibit hypoxia (low oxygen) and hypoxic tumours often respond poorly to therapy. Here, the authors quantify hypoxia in 1188 tumours from 27 cancer types, showing elevated hypoxia links to increased mutational load, directing evolutionary trajectories.