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Aim Myocardial infarction remains the leading cause of heart failure. The adult human heart lacks the capacity to undergo endogenous regeneration. New blood vessel growth is integral to regenerative medicine necessitating a comprehensive understanding of the pathways that regulate vascular regeneration. We sought to define the transcriptomic dynamics of coronary endothelial cells following ischaemic injuries in the developing and adult mouse and human heart and to identify new mechanistic insights and targets for cardiovascular regeneration. Methods and results We carried out a comprehensive meta-analysis of integrated single-cell RNA-sequencing data of coronary vascular endothelial cells from the developing and adult mouse and human heart spanning healthy and acute and chronic ischaemic cardiac disease. We identified species-conserved gene regulatory pathways aligned to endogenous neovascularization. We annotated injury-associated temporal shifts of the endothelial transcriptome and validated four genes: VEGF-C, KLF4, EGR1, and ZFP36. Moreover, we showed that ZFP36 regulates human coronary endothelial cell proliferation and defined that VEGF-C administration in vivo enhances clonal expansion of the cardiac vasculature post-myocardial infarction. Finally, we constructed a coronary endothelial cell meta-atlas, CrescENDO, to empower future in-depth research to target pathways associated with coronary neovascularization. Conclusion We present a high-resolution single-cell meta-atlas of healthy and injured coronary endothelial cells in the mouse and human heart, revealing a suite of novel targets with great potential to promote vascular regeneration, and providing a rich resource for therapeutic development. [ABSTRACT FROM AUTHOR]

Aims  To investigate the change in atherosclerotic plaque volume in patients with chronic kidney disease (CKD) and declining renal function, using coronary computed tomography angiography (CCTA). Methods and results In total, 891 participants with analysable serial CCTA and available glomerular filtration rate (GFR, derived using Cockcroft–Gault formulae) at baseline (CCTA 1) and follow-up (CCTA 2) were included. CKD was defined as GFR <60 mL/min/1.73 m2. Declining renal function was defined as ≥10% drop in GFR from the baseline. Quantitative assessment of plaque volume and composition were performed on both scans. There were 203 participants with CKD and 688 without CKD. CKD was associated with higher baseline total plaque volume, but similar plaque progression, measured by crude (57.5 ± 3.4 vs. 65.9 ± 7.7 mm3/year, P  = 0.28) or annualized (17.3 ± 1.0 vs. 19.9 ± 2.0 mm3/year, P  = 0.25) change in total plaque volume. There were 709 participants with stable GFR and 182 with declining GFR. Declining renal function was independently associated with plaque progression, with higher crude (54.1 ± 3.2 vs. 80.2 ± 9.0 mm3/year, P  < 0.01) or annualized (16.4 ± 0.9 vs. 23.9 ± 2.6 mm3/year, P  < 0.01) increase in total plaque volume. In CKD, plaque progression was driven by calcified plaques whereas in patients with declining renal function, it was driven by non-calcified plaques. Conclusion Decline in renal function was associated with more rapid plaque progression, whereas the presence of CKD was not. [ABSTRACT FROM AUTHOR]

Objective We aimed to define the potential complications of intra-articular steroid injections into the lateral C1-2 articulations and safety margins to the relevant structures. Methods A total of 488 contrast-enhanced computed tomography angiogram (CTA) "arch to vertex" studies were retrospectively reviewed for theoretical intersection of the vertebral artery or thecal sac and distance of the named structures from the anticipated/theoretical trajectory of injection into the lateral C1-C2 joint. Results Patients were 60.4±15.8 years old and 55.5% male. In total, seven vertebral arteries and 11 thecal sac theoretical intersections were found. In cases without a direct intersection, the distance from the trajectory (range) was 0.71±0.18 (0.22–1.44) cm to the vertebral artery and 0.6±0.22 (0.14–1.8) cm to the thecal sac. Conclusions Although injection of steroid into the lateral C1-C2 articulation for pain management has historically been reported to carry risk of severe complications due to close proximity and location variability of surrounding structures, our study quantifies the potential risk of such injections. Further, our analysis suggests that preprocedural imaging should be considered. [ABSTRACT FROM AUTHOR]

A bstract The high risk of insertional oncogenesis reported in clinical trials using integrating retroviral vectors to genetically modify hematopoietic stem and progenitor cells (HSPCs) requires the development of safety strategies to minimize risks associated with novel cell and gene therapies. The ability to ablate genetically modified cells in vivo is desirable, should an abnormal clone emerge. Inclusion of 'suicide genes' in vectors to facilitate targeted ablation of vector-containing abnormal clones in vivo is one potential safety approach. We tested whether the inclusion of the 'inducible Caspase-9' (iCasp9) suicide gene in a gamma-retroviral vector facilitated efficient elimination of vector-containing HSPCs and their hematopoietic progeny in vivo long-term, in an autologous non-human primate transplantation model. Following stable engraftment of iCasp9 expressing hematopoietic cells in rhesus macaques, administration of AP1903, a chemical inducer of dimerization able to activate iCasp9, specifically eliminated vector-containing cells in all hematopoietic lineages long-term, suggesting activity at the HSPC level. Between 75% and 94% of vector-containing cells were eliminated by well-tolerated AP1903 dosing, but lack of complete ablation was linked to lower iCasp9 expression in residual cells. Further investigation of resistance mechanisms demonstrated upregulation of Bcl-2 in hematopoietic cell lines transduced with the vector and resistant to AP1903 ablation. These results demonstrate both the potential and the limitations of safety approaches using iCasp9 to HSPC-targeted gene therapy settings, in a model with great relevance to clinical development. S tem C ells 2015;33:91-100 [ABSTRACT FROM AUTHOR]

Previous murine studies have suggested that retroviral multidrug resistance 1 (MDR1) gene transfer may be associated with a myeloproliferative disorder. Analyses at a clonal level and prolonged long-term follow-up in a model with more direct relevance to human biology were lacking. In this study, we analyzed the contribution of individual CD34-selected peripheral blood progenitor cells to long-term rhesus macaque hematopoiesis after transduction with a retroviral vector either expressing the multidrug resistance 1 gene (HaMDR1 vector) or expressing the neomycin resistance (NeoR) gene (G1Na vector). We found a total of 122 contributing clones from 8 weeks up to 4 years after transplantation. One hundred two clones contained the G1Na vector, whereas only 20 clones contained the HaMDR1 vector. Here, we show for the first time realtime polymerase chain reaction based quantification of individual transduced cell clones constituting 0.0008% ± 0.0003% to 0.0041% ± 0.00032% of primate peripheral blood cells. No clonal dominance was observed. [ABSTRACT FROM AUTHOR]