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Rudnicki, M.

Publications and source records attributed to Rudnicki, M..

3 recordsLinked to original sources

Sex-specific remodeling of the human adipose tissue vascular niche in obesity

AO_SCPLOWBSTRACTC_SCPLOWObesity remodels the subcutaneous adipose tissue (SAT) vasculature and contributes to cardiometabolic risk, yet potential sex differences in this process remain poorly defined. Here, we integrated single-nucleus transcriptomics and histological analyses of human SAT to reveal pronounced sexual dimorphism within the vascular niche. Obese males exhibit mural cell loss, increased collagen deposition, and inflammatory endothelial activation, including enhanced antigen presentation programs. In contrast, females display preserved mural coverage and increased lipid-handling and redox-adaptive pathways. These coordinated structural and transcriptional differences position the adipose endothelium as a sex-divergent regulator of obesity-associated cardiometabolic vulnerability.

cell biology↗

CreER activation transiently impairs angiogenesis by slowing endothelial proliferation

Tamoxifen-inducible gene targeting in mice with estrogen receptor-dependent Cre (CreER) recombinase has enormously advanced vascular biology research. However, CreER activation under the control of vascular endothelial promoters is now recognized to cause off-target effects that impair angiogenesis in the widely used perinatal mouse retina model. Although ubiquitously expressed CreER is also used to study retinal angiogenesis, it remains unknown whether it causes similar or more severe off-target effects compared to endothelial-selective CreER activation. Moreover, the cellular processes disrupted by CreER-induced endothelial toxicity remain to be identified. Here, we demonstrate that ubiquitous CreER activation in postnatal mice decreases body growth throughout the period of retinal angiogenesis and impairs retinal angiogenesis in a tamoxifen dose-dependent manner. We further show that CreER activation from both endothelial and ubiquitously expressed CreER transgenes suppresses endothelial cell proliferation downstream of p21/CDKNA1 upregulation. By contrast, we find that p21/CDKNA1 is not upregulated in quiescent adult retinal endothelium, and that CreER-induced postnatal angiogenesis defects recover two weeks after tamoxifen discontinuation. Altogether, our findings indicate that ubiquitous promoters should be avoided for CreER expression when studying endothelial genes, and that short-term retinal angiogenesis studies require endothelial CreER toxicity controls that may be less critical for adult vascular studies.

developmental biology↗

NRP1-expressing myeloid cells promote arteriogenesis in the ischemic limb

Peripheral arterial disease can cause limb threatening blood flow restriction, requiring amputation in up to a third of patients despite contemporary treatments. Stimulating new blood vessel growth in ischemic limbs using growth factors such as VEGF-A or supplying mixed cell populations via autologous transplantation has been investigated as a therapy for surgically intractable cases, but to date has proven ineffective in randomised controlled clinical studies. To identify more potent pro-arteriogenic cell populations, we have investigated VEGF-A responsive myeloid cell populations in a mouse model of severe hindlimb ischemia. We found that NRP1 ablation from monocytes and macrophages impaired arteriogenesis in the adductor muscle and flow recovery in the injured limb. Vice versa, the exogenous delivery of NRP1-expressing (but not NRP1-negative) macrophages enhanced arteriogenesis in the adductor and flow recovery in the ischemic limb in a VEGF signalling-dependent manner. Further, patient-derived NRP1-expressing monocytes promoted vascular morphogenesis ex vivo. As the levels of circulating NRP1-expressing monocytes were raised in patients with limb ischemia, the therapeutic delivery of autologous NRP1-expressing monocytes could be explored as a treatment for critical limb ischemia.

pathology↗