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Biology subjects

Cano, I.

Publications and source records attributed to Cano, I..

4 recordsLinked to original sources

SIRT5 acts in the tumor microenvironment via endothelial cell metabolism to support breast cancer growth

Triple-negative breast cancer (TNBC) is characterized by aggressive progression and poor prognosis, partly due to abnormal angiogenesis. While the metabolic reprogramming of tumor cells is well characterized, the metabolic regulation of tumor-associated endothelial cells (ECs) remains unclear. Here, we identified the mitochondrial deacylase SIRT5, which has established tumor-promoting roles in TNBC cells, as a key regulator of endothelial metabolic homeostasis and tumor angiogenesis. SIRT5-deficient host mice showed significant defects in supporting the growth of orthotopic SIRT5-proficient mammary tumor transplants, and the resulting neoplasms showed defects in tumor vascularization. In a 3D microfluidic vessel-on-chip model, SIRT5 loss compromised vascular barrier integrity and EC sprouting. Mechanistically, SIRT5-deficient ECs exhibited diminished mitochondrial respiratory capacity but apparently normal glycolysis. SIRT5 loss also caused increased mitochondrial reactive oxygen species levels, and a mitochondrial antioxidant rescued the endothelial cell defects following SIRT5 loss, indicating that SIRT5-mediated mitochondrial redox homeostasis in the tumor microenvironment is necessary to maintain vascular function. Orthotopic co-transplantation of TNBC and EC cells with or without SIRT5 knockdown demonstrated that endothelial SIRT5 promotes increased tumor growth in vivo. These results suggest that targeting SIRT5 offers a potential therapeutic strategy to disrupt tumor angiogenesis and suppress TNBC progression by targeting the metabolic vulnerabilities of the tumor endothelium.

cancer biology↗

Endomucin knockout leads to delayed retinal vascular development and reduced ocular pathological neovascularization

Endomucin (EMCN), an endothelial-specific glycocalyx component highly expressed in capillary and venous endothelium, plays a critical role in regulating VEGF receptor 2 (VEGFR2) endocytosis and downstream VEGF signaling. Using the first global EMCN knockout mouse model, we investigated the effects of EMCN deficiency on retinal vascularization during development and pathological angiogenesis. We found relatively high expression of EMCN in choroidal capillaries and retinal vasculature. Emcn-/- mice exhibited delayed retinal vascularization at postnatal day 5, with fewer tip cells and reduced vessel density. Ultrastructural examination revealed disrupted and reduced fenestrations in choroidal capillary endothelium. In an oxygen-induced retinopathy model, while Emcn-/- mice showed no significant difference in avascular area compared to Emcn+/+ mice at postnatal day 12, there was a significant reduction in neovascular tufts in Emcn-/- mice at postnatal day 17. Similarly, in a laser-induced choroidal neovascularization model, Emcn-/- mice showed a significant reduction in vascular leakage and lesion size. These findings suggest that EMCN plays a critical role in both vascular development and pathological neovascularization, highlighting its potential as a target for anti-angiogenic therapies.

pathology↗

Deletion of the endothelial glycocalyx component endomucin leads to impaired glomerular structure and function

BackgroundEndomucin (EMCN), an endothelial-specific glycocalyx component, was found to be highly expressed by the endothelium of the renal glomerulus. We reported an anti-inflammatory role of EMCN and its involvement in the regulation of vascular endothelial growth factor (VEGF) activity through modulating VEGF receptor 2 (VEGFR2) endocytosis. The goal of this study is to investigate the phenotypic and functional effects of EMCN deficiency using the first global EMCN knockout mouse model. MethodsGlobal EMCN knockout mice were generated by crossing EMCN-floxed mice with ROSA26-Cre mice. Flow cytometry was employed to analyze infiltrating myeloid cells in the kidneys. The ultrastructure of the glomerular filtration barrier was examined by transmission electron microscopy, while urinary albumin, creatinine, and total protein levels were analyzed from freshly collected urine samples. Expression and localization of EMCN, EGFP, CD45, CD31, CD34, podocin, albumin, and -smooth muscle actin were examined by immunohistochemistry. Mice were weighed regularly, and their systemic blood pressure was measured using a non-invasive tail-cuff system. Glomerular endothelial cells and podocytes were isolated by fluorescence-activated cell sorting for RNA-seq. Transcriptional profiles were analyzed to identify differentially expressed genes in both endothelium and podocytes, followed by gene ontology analysis of up- and down-regulated genes. Protein levels of EMCN, albumin, and podocin were quantified by Western blot. ResultsEMCN-/- mice were viable with no gross anatomical defects in kidneys. The EMCN-/- mice exhibited increased infiltration of CD45+ cells, with an increased proportion of Ly6GhighLy6Chigh myeloid cells and higher VCAM-1 expression. EMCN-/- mice displayed albuminuria with increased albumin in the Bowmans space compared to the EMCN+/+ littermates. Glomeruli in EMCN-/- mice revealed fused and effaced podocyte foot processes and disorganized endothelial fenestrations. We found no significant difference in blood pressure between EMCN knockout mice and their wild-type littermates. RNA-seq of glomerular endothelial cells revealed downregulation of cell-cell adhesion and MAPK/ERK pathways, along with glycocalyx and extracellular matrix remodeling. In podocytes, we observed reduced VEGF signaling and alterations in cytoskeletal organization. Notably, there was a significant decrease in both mRNA and protein levels of podocin, a key component of the slit diaphragm. ConclusionOur study demonstrates a critical role of the endothelial marker EMCN in supporting normal glomerular filtration barrier structure and function by maintaining glomerular endothelial tight junction and homeostasis and podocyte function through endothelial-podocyte crosstalk.

pathology↗

Identification of a pharmaceutical biostasis inducer that slows metabolism in multiple vertebrates that do not hibernate

Drugs that induce reversible slowing of metabolic and physiological processes would have great value for organ preservation, especially for organs with high susceptibility to hypoxia-reperfusion injury, such as the heart. Using whole-organism screening of metabolism, mobility, and development in Xenopus, we identified an existing drug, SNC80, that rapidly and reversibly slows biochemical and metabolic activities while preserving cell and tissue viability. Although SNC80 was developed as a delta opioid receptor activator, we discovered that its ability to slow metabolism is independent of its opioid modulating activity as a novel SNC80 analog (WB3) with almost 1,000 times less delta opioid receptor binding activity is equally active. Metabolic suppression was also achieved using SNC80 in microfluidic human organs-on-chips, as well as in explanted whole porcine hearts and limbs, demonstrating the cross-species relevance of this approach and potential clinical relevance for surgical transplantation. Pharmacological induction of physiological slowing in combination with organ perfusion transport systems may offer a new therapeutic approach for tissue and organ preservation for transplantation, trauma management, and enhancing patient survival in remote and low-resource locations.

bioengineering↗