Biology subjects

Camillo, C.

Publications and source records attributed to Camillo, C..

5 recordsLinked to original sources

bioRxiv2026

Lung endothelial niche signaling governs self-renewal and fate transitions of human alveolar stem cells

Chronic lung diseases such as pulmonary fibrosis are characterized by the irreversible loss of alveolar type 1 (AT1) cells, yet the mechanisms governing human alveolar stem cell self-renewal and differentiation remain poorly defined. Here, we identify a lung endothelial niche that sustains the self-renewal of human alveolar type 2 (AT2) stem cells through MAPK signaling, enabling robust long-term expansion while preserving stem cell fate. Although YAP activation initiates AT1 transcriptional programs, it is insufficient to complete lineage maturation. We show that MAPK inhibition together with LATS inhibition promotes nuclear translocation of YAP, enhancing AT1 differentiation. Expanded human AT2 stem cells engraft in fibrotic lungs and contribute to alveolar regeneration while undergoing directed differentiation within diseased human lung tissue. Together, our findings define a niche-controlled signaling mechanism governing human alveolar stem cell fate and advance our understanding of alveolar regeneration.

cell biology↗

bioRxiv2025

In vivo imaging of reactive oxygen species after myocardial ischemia-reperfusion injury: a large animal multimodal imaging and transcriptomic study

BackgroundReactive oxygen species (ROS) contribute to myocardial ischemia-reperfusion injury (IRI), but in-vivo data on the spatial myocardial distribution and systemic effects of ROS after IRI remain limited. This multimodal CMR and PET/CT study aimed to non-invasively image ROS activity in a clinically-relevant swine model of IRI using [18F]ROStrace, a fluorine-18-labeled analogue of dihydroethidium (DHE), and to investigate regional changes in ROS activity in the infarcted myocardium during the subacute post-IRI phase. MethodsIRI was induced by percutaneous occlusion of the left anterior descending artery for 90 minutes in swine (N=9). CMR and whole-body PET/CT imaging with [18F]ROStrace were performed before myocardial infarction (MI) and 3-5 days post-MI to assess ROS in non-infarct myocardium, lungs, bone marrow, spleen and skeletal muscle. Late gadolinium enhanced CMR was performed to structurally characterize infarct regions. Post-MI, in vivo [18F]ROStrace signal in infarcted myocardium was compared with remote, non-infarcted myocardium and validated via ex vivo DHE fluorescent imaging. Bulk RNA-sequencing (RNA-seq) and Gene Ontology pathway analysis were conducted on biopsies from infarct and remote myocardial tissue to identify differentially expressed genes and pathways connected to oxidative stress. ResultsDuring the subacute phase following MI, [18F]ROStrace fractional uptake rate (FUR; min-1) was significantly increased in skeletal muscle, compared to baseline (0.011{+/-}0.003 vs 0.016{+/-}0.005, p=0.04), with a trend toward increased FUR in bone marrow (0.046{+/-}0.009 vs 0.056{+/-}0.011, p=0.12) and the left ventricular free wall (0.067{+/-}0.007 vs 0.073{+/-}0.010, p=0.15). Within the myocardium, [18F]ROStrace FUR ((min-1)/(mL/min/g)) was significantly higher in infarcted compared to non-infarcted myocardium regions (0.110{+/-}0.034, vs 0.148{+/-}0.035, p=0.0005). DHE staining confirmed elevated ROS levels in the infarcted myocardium. RNA-seq identified 8,707 differentially expressed genes between infarct and remote myocardium, with downregulated pathways in the infarct associated with mitochondrial function, cellular respiration, and metabolic adaptation. ConclusionThis study demonstrated MI ROS imaging using [18F]ROStrace using a whole-body PET/CT scanner and structural assessment with CMR. Systemic and myocardial increases in ROS activity were observed post-MI, accompanied by substantial molecular alterations in infarcted tissue. These findings show potential imaging strategies to evaluate therapeutic targets that can mitigate oxidative stress after MI.

bioengineering↗

bioRxiv2025

Comparison of oviposition and adult trapping to monitor wMel introgression for Wolbachia-based vector control

Wolbachia introgression into Aedes aegypti mosquito populations has been shown to be effective in preventing dengue and is being evaluated for WHO prequalification. Monitoring the long-term introgression of Wolbachia (wMel)-positive Aedes aegypti mosquitoes, however, requires labor-intensive and costly BG-Sentinel traps (BG-traps). More affordable alternatives, such as using oviposition traps (ovitraps), have not been fully evaluated. Ae. aegypti eggs and adults were collected from 124 ovitraps and 237 BG-traps, respectively, across 12 clusters in Belo Horizonte, Brazil from March to May 2023 as part of the EVITA Dengue trial. We used a qPCR assay to detect wMel in a sample of L3-L4 stage larvae (up to 29) that were reared from eggs in ovitraps and adults from BG-traps (up to 10 per BG-trap). We used mixed effects models to compare estimates of cluster-level wMel introgression from ovitrap and BG-trap data over time. Among 3,675 larvae reared from ovitraps, wMel prevalence was 0.50 (95% CI: 0.48-0.51). Among 1,244 adult Ae. aegypti tested from BG-traps, wMel prevalence was 0.45 (95% CI: 0.42-0.48). Cluster-level wMel introgression in larvae and adults was highly correlated (Spearmans r = 0.70, p = 6.71e-06). Multivariate analysis found that ovitrap estimates of introgression were associated with BG-trap estimates in the same month when models incorporated the previous months ovitrap wMel-positive count, the proportion of wMel in ovitraps in the current and previous month, and Ae. aegypti abundance. Leveraging this model, predicted wMel introgression from ovitrap data were highly correlated with observed introgression from BG-trap data (rs,counts=0.98, p=1.53e-14; rs,prevalences=0.82, p=0.11e-05) and provided greater precision than crude ovitrap-based estimates. These findings indicate that ovitrap-based monitoring represents a low cost, more efficient approach to evaluating introgression as the Wolbachia-based interventions are scaled up and implemented broadly in high burden regions for dengue and other arboviral diseases. Author SummaryDengue fever is a major global health burden, and one promising way to control it is by releasing Aedes aegypti mosquitoes infected with a bacteria called Wolbachia. This bacteria reduces the mosquitoes ability to spread dengue. However, monitoring the success of Wolbachia in mosquito populations over time requires expensive and labor-intensive traps. Our study explored a more affordable alternative: using oviposition traps (ovitraps), which collect mosquito eggs instead of adults. In Belo Horizonte, Brazil, we compared data from eggs collected in ovitraps with data from standard mosquito traps (BG-traps) that catch adult mosquitoes. By analyzing the mosquitoes for Wolbachia, we found that the egg-based method provided reliable estimates of Wolbachia levels in the mosquito population. These results suggest that ovitraps could be a cost-effective and efficient way to monitor Wolbachias spread. This approach could help improve dengue prevention efforts, making it easier for public health programs to track and expand this control strategy in areas where dengue is a major concern.

ecology↗

bioRxiv2021

RAGE antagonist peptide mitigates AGE-mediated endothelial hyperpermeability and accumulation of glycoxidation products in human ascending aortas and in a murine model of aortic aneurysm

BackgroundAortic dissection and aneurysm are the result of altered biomechanical forces associated with structural weakening of the aortic wall caused by genetic or acquired factors. Current guidelines recommend replacement of the ascending aorta when the diameter is >5.5 cm in tricuspid aortic valve patients. Aortopathies are associated with altered wall stress and stiffness as well as endothelial cell dysfunction and synthetic vascular smooth muscle cell (VSMC) phenotype. We reported that these mechanisms are mediated by glycoxidation products [Reactive oxygen species (ROS) and Advance Glycation End products (AGE)]. This study addresses the role of glycoxidation on endothelial function and AGE-mediated aortic stiffness. Hypothesis and aimsHere we investigate how circulating glycation products infiltrate the aortic wall via AGE-mediated endothelial hyperpermeability and contribute to both VSMC synthetic phenotype and extracellular matrix (ECM) remodeling in vivo and ex vivo. We also study how RAGE antagonist peptide (RAP) can rescue the effect of AGEs in vitro and in vivo in eNOS-/- vs WT mice. Methods and resultsHuman ascending aortas (n=30) were analyzed for AGE, ROS, and ECM markers. In vitro glycation was obtained by treating VSMC or human and murine aortas with glyoxal. Endothelial permeability was measured under glycation treatment. Vascular stiffness was measured by a pressure myograph comparing wild-type mice {+/-} glyoxal. eNOS-/- mice, a model of increased endothelial permeability, were treated for 28 days with hyperlipidemic diet {+/-} Angiotensin II (1000ng/kg/min) with or without anti-glycation treatment (RAP 20mg/kg). Echo data of aortic diameter were collected. Murine vascular stiffness was measured by a pressure myograph (n=5/group). Glycoxidation products were detected in all human aortas independently of aortic diameter, with stronger accumulation on the lumen and the adventitia layer. AGEs increased endothelial permeability, induce synthetic phenotypic switch in human VSMCs, and inhibit cell migration. RAP pre-treatment rescue the effect of glyoxal on endothelial cells. Ex vivo glycation treatment of murine arteries impacted on ECM and increased stiffness. Aortic stiffness was higher in eNOS-/- vs WT mice. Ang II-mediated aortopathies results in aortic dilation, and AGE/ROS accumulation, which is rescued by RAGE antagonist peptide treatment of eNOS-/- mice. ConclusionsGlycoxidation reaction mediate EC permeability, VSMCs phenotype, and ECM remodeling leading to dysfunctional microstructure of the ascending aorta, altered vascular stiffness and increasing aortic susceptibility to dilation and rupture. Moreover, we show that RAP can mitigate AGE-mediated endothelial hyper-permeability in vitro and impact on ascending aneurysm in vivo

physiology↗

bioRxiv2020

Latrophilin 2 controls vascular morphogenesis and function by inhibiting endothelial cell adhesion and YAP/TAZ mechanosignaling

Dynamic modulation of endothelial cell-to-cell and cell-to-extracellular matrix (ECM) adhesion is essential for blood vessel patterning and functioning. Yet, the molecular mechanisms involved in this process have not been completely deciphered. We identify the adhesion G protein-coupled receptor (ADGR) Latrophilin 2 (LPHN2) as a novel determinant of endothelial cell (EC) adhesion and barrier function. In cultured ECs, endogenous LPHN2 localizes at ECM contacts, signals through cAMP/Rap1, and inhibits focal adhesion (FA) formation and nuclear localization of YAP/TAZ transcriptional regulators, while promoting tight junction (TJ) assembly. ECs also express an endogenous LPHN2 ligand, fibronectin-leucine-rich transmembrane 2 (FLRT2), that prevents ECM-elicited EC behaviors in a LPHN2-dependent manner. Vascular ECs of lphn2a knock-out zebrafish embryos become abnormally stretched, display a hyperactive YAP/TAZ pathway, and lack proper intercellular TJs. Consistently, blood vessels are hyperpermeable and intravascularly injected cancer cells extravasate more easily in lphn2a null animals. Thus, LPHN2 ligands, such as FLRT2, may be therapeutically exploited to interfere with cancer metastatic dissemination. SUMMARYCamillo et al. show that the LPHN2 receptor, upon activation by FLRT2 ligand, inhibits focal adhesion formation and promotes tight junction assembly in endothelial cells. Blood vessels of lphn2a null animals are hyperpermeable and injected cancer cells extravasate more easily.

cell biology↗