Biology subjects

Ferro, V.

Publications and source records attributed to Ferro, V..

7 recordsLinked to original sources

bioRxiv2025

A Multimodal Adaptive Optical Microscope For In Vivo Imaging from Molecules to Organisms

Understanding biological systems requires observing features and processes across vast spatial and temporal scales, spanning nanometers to centimeters and milliseconds to days, often using multiple imaging modalities within complex native microenvironments. Yet, achieving this comprehensive view is challenging because microscopes optimized for specific tasks typically lack versatility due to inherent optical and sample handling trade-offs, and frequently suffer performance degradation from sample-induced optical aberrations in multicellular contexts. Here, we present MOSAIC, a reconfigurable microscope that integrates multiple advanced imaging techniques including light-sheet, label-free, super-resolution, and multi-photon, all equipped with adaptive optics. MOSAIC enables non-invasive imaging of subcellular dynamics in both cultured cells and live multicellular organisms, nanoscale mapping of molecular architectures across millimeter-scale expanded tissues, and structural/functional neural imaging within live mice. MOSAIC facilitates correlative studies across biological scales within the same specimen, providing an integrated platform for broad biological investigation.

cell biology↗

bioRxiv2025

NNMT promotes tubular senescence and fibrosis in chronic kidney disease

Chronic kidney disease (CKD) is a major global health issue, projected to become the fifth leading cause of mortality by 2040. Renal tubular cell senescence is a key driver of kidney fibrosis, the final manifestation of CKD. However, current treatment strategies, do not target senescent cells, as the underlying mechanisms driving this dysfunctional phenotype remain poorly described. Here, we identify nicotinamide-N-methyltransferase (NNMT), as a critical mediator of tubular senescence and fibrosis in CKD. Using human RNAseq profiles of CKD, we show that NNMT expression in the renal tubulointerstitium is strongly associated with CKD pathology and transcriptional signatures of cellular senescence. In human diabetic kidney disease biopsies, NNMT levels correlate with the senescence marker p21, kidney function decline, and fibrosis. Spatial transcriptomics further highlights that NNMT-positive tubules are senescent, fibrotic, and surrounded by a pro-inflammatory microenvironment. Preclinical models of early-stage CKD, show upregulation of NNMT and association with senescence. Overexpression of NNMT in TGF-{beta}-stimulated tubular epithelial cells promotes senescence and partial epithelial-to-mesenchymal transition (EMT), while inhibition of NNMT in kidney cells and organoids is protective. Altogether, we identify NNMT as a novel therapeutic target in the early stages of CKD with the potential to reduce tubular senescence, fibrosis and significantly slow disease progression.

cell biology↗

bioRxiv2023

Substrate reduction therapy in a Drosophila melanogaster model of Sanfilippo syndrome

Sanfilippo syndrome, or mucopolysaccharidosis (MPS) types A, B, C or D, are neurodegenerative lysosomal storage disorders resulting from the lack of a specific enzyme involved in heparan sulfate (HS) catabolism. Several treatments are under evaluation for these conditions including substrate reduction therapy, with the most studied compound of this class being the isoflavone genistein. However, recent outcomes from a Phase III clinical trial have shown that high dose oral genistein does not significantly improve neurodevelopmental outcomes in MPS III patients. Here, we have tested an N-acetylglucosamine (GlcNAc) analogue inhibitor, 4-deoxy-GlcNAc peracetate, at reducing HS accumulation in cells from patients with Sanfilippo syndrome as a novel substrate reduction therapy. We then confirmed the capacity of this compound to modulate substrate accumulation in vivo in a Sanfilippo Drosophila model. Treatment with this compound significantly reduced HS in cultured MPS IIIA patient fibroblasts in a time-dependent manner. Neuronal and ubiquitous knockdown Drosophila models of MPS IIIC displaying elevated heparan sulfate and behavioural defects exhibited reduced HS burden relative to vehicle-treated controls following oral feeding with the GlcNAc analogue inhibitor. These findings indicate that this compound may be beneficial in slowing the accumulation of HS and may represent a novel therapeutic for Sanfilippo syndrome.

neuroscience↗

bioRxiv2022

SARS-CoV-2 triggers complement activation through interactions with heparan sulfate

The complement system has been heavily implicated in severe COVID-19 with clinical studies revealing widespread gene induction, deposition, and activation. However, the mechanism by which complement is activated in this disease remains incompletely understood. Herein we examined the relationship between SARS-CoV-2 and complement by inoculating the virus in lepirudin-anticoagulated human blood. This caused progressive C5a production after 30 minutes and 24 hours, which was blocked entirely by inhibitors for factor B, C3, C5, and heparan sulfate. However, this phenomenon could not be replicated in cell-free plasma, highlighting the requirement for cell surface deposition of complement and interactions with heparan sulfate. Additional functional analysis revealed that complement-dependent granulocyte and monocyte activation was delayed. Indeed, C5aR1 internalisation and CD11b upregulation on these cells only occurred after 24 hours. Thus, SARS-CoV-2 is a non-canonical complement activator that triggers the alternative pathway through interactions with heparan sulfate.

immunology↗

bioRxiv2020

Pixatimod (PG545), a clinical-stage heparan sulfate mimetic, is a potent inhibitor of the SARS-CoV-2 virus

Heparan sulfate (HS) is a cell surface polysaccharide recently identified as a co-receptor with the ACE2 protein for recognition of the S1 spike protein on SARS-CoV-2 virus, providing a tractable new target for therapeutic intervention. Clinically-used heparins demonstrate inhibitory activity, but world supplies are limited, necessitating alternative solutions. Synthetic HS mimetic pixatimod is a drug candidate for cancer with immunomodulatory and heparanase-inhibiting properties. Here we show that pixatimod binds to and destabilizes the SARS-CoV-2 spike protein receptor binding domain (S1-RBD), and directly inhibits its binding to human ACE2, consistent with molecular modelling identification of multiple molecular contacts and overlapping pixatimod and ACE2 binding sites. Assays with multiple clinical isolates of live SARS-CoV-2 virus show that pixatimod potently inhibits infection of monkey Vero E6 and human bronchial epithelial cells at concentrations within its safe therapeutic dose range. Furthermore, in a K18-hACE2 mouse model pixatimod demonstrates that pixatimod markedly attenuates SARS-CoV-2 viral titer and COVID-19-like symptoms. This demonstration of potent anti-SARS-CoV-2 activity establishes proof-of-concept for targeting the HS-Spike protein-ACE2 axis with synthetic HS mimetics. Together with other known activities of pixatimod our data provides a strong rationale for its clinical investigation as a potential multimodal therapeutic to address the COVID-19 pandemic.

microbiology↗

bioRxiv2020

Heparanase promotes Syndecan-1 expression to mediate fibrillar collagen and mammographic density in human breast tissue cultured ex vivo.

Mammographic density (MD) is a strong and independent factor for breast cancer (BC) risk and is increasingly associated with BC progression. We have previously shown in mice that high MD, which is characterised by the preponderance of a fibrous stroma, facilitates BC xenograft growth and metastasis. This stroma is rich in extracellular matrix (ECM) factors, including heparan sulfate proteoglycans (HSPGs), such as the BC-associated syndecan-1 (SDC1). These proteoglycans tether growth factors, which are released by heparanase (HPSE). MD is positively associated with estrogen exposure and, in cell models, estrogen has been implicated in the upregulation of HPSE, the activity of which promotes SDC expression. Herein we describe a novel measurement approach (single-sided NMR) using a patient-derived explant (PDE) model of normal human (female) mammary tissue cultured ex vivo to investigate the role(s) of HPSE and SDC1 on MD. Relative HSPG gene and protein analyses determined in patient-paired high versus low MD tissues identified SDC1 and SDC4 as potential mediators of MD. Using the PDE model we demonstrate that HPSE promotes SDC1 rather than SDC4 expression and cleavage, leading to increased MD. In this model system, synstatin (SSTN), an SDC1 inhibitory peptide designed to decouple SDC1-ITGv{beta}3 parallel collagen alignment, reduced the abundance of fibrillar collagen as assessed by picrosirius red viewed under polarised light, and reduced MD. Our results reveal a potential role for HPSE in maintaining MD via its direct regulation of SDC1, which in turn physically tethers collagen into aligned fibres characteristic of MD. We propose that inhibitors of HPSE and/or SDC1 may afford an opportunity to reduce MD in high BC risk individuals and reduce MD-associated BC progression in conjunction with established BC therapies.

cancer biology↗

bioRxiv2018

Measurement of junctional tension in epithelial cells at the onset of primitive streak formation in the chick embryo via non-destructive optical manipulation

Oriented cell intercalations and cell shape changes are key determinants of large-scale epithelial cell sheet deformations occurring during gastrulation in many organisms. In several cases directional intercalation and cell shape changes have been shown to be associated with a planar cell polarity in the organisation of the actinmyosin cytoskeleton of epithelial cells. This polarised cytoskeletal organisation has been postulated to reflect the directional tension necessary to drive and orient directional cell intercalations. We have now further characterised and applied a recently introduced non-destructive optical manipulation technique to measure the tension in individual cell junctions in the epiblast of chick embryos in the early stages of primitive streak formation. We have measured junctional tension as a function of position and orientation. Junctional tension of mesendoderm cells, the tissue that drives the formation of the streak, is higher than tension of junctions of cells in other parts of the epiblast. Furthermore, in the mesendoderm junctional tension is higher in the direction of intercalation. The data are fitted best with a Maxwell model and we find that both junctional tension and relaxation time are dependent on myosin activity.

developmental biology↗