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Biology subjects

Castiglione, A.

Publications and source records attributed to Castiglione, A..

5 recordsLinked to original sources

A TSST 1 structural motif disrupts endothelial programs required for vascular regeneration.

Staphylococcus aureus causes profound vascular damage during infection, where it inflicts vascular injury across organs and generates lesions that fail to heal. Superantigens are major virulence factors in S. aureus infections, yet their direct effects on vascular repair remain unclear. We provide evidence that TSST-1 disrupts endothelial regeneration through coordinated mechanisms. TSST-1 interferes with collective directed migration, impairing endothelial cell directional persistence and preventing re-endothelialization in vitro. These defects stem from cytoskeletal disorganization, characterized by stress fiber accumulation and loss of lamellipodia, and broad suppression of motility-associated secreted factors. In an ex vivo aortic ring assay, TSST-1 suppresses angiogenic sprouting and generates dysmorphic vascular networks. Proteomic profiling reveals a shift toward matrix rigidity, adhesion stabilization, and overall suppression of angiogenesis. These activities map to a conserved dodecapeptide motif. Hence, TSST-1 suppression of vascular repair may convert sites of tissue injury into persistently non-healing niches suited for S. aureus persistence.

cell biology↗

Pre-clinical evaluation of a gene therapy candidate for SOD1-ALS shows improved survival and signs of inflammation in the CNS of treated mice.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by motor neurons loss (MN). In 15-20% of familial ALS cases, mutations in the superoxide dismutase 1 (SOD1) gene are the underlying cause. Targeting human SOD1 (hSOD1) toxicity has emerged as a promising approach to treat SOD1-ALS. We previously demonstrated the efficacy of an exon-skipping strategy using a self-complementary AAVrh10-U7-hSOD1 vector in SOD1G93A mice achieving significant hSOD1 silencing. In this study, we optimized the therapeutic protocol by conducting a dose-finding and biodistribution study of scAAVrh10-U7-hSOD1 following a single intracerebroventricular injection in adult SOD1G93A mice. Our findings demonstrate a dose-dependent reduction in mutant hSOD1 levels in the cortex, spinal cord, and peripheral tissues, sustained for up to 60 days post-injection. In vivo, some adverse effects were noted mostly at the highest dose, with inflammation early post-injection and persistent microglial activation in the brain observed around the injection site. Importantly, the medium-dose treatment extended mean survival by up to 27% with a much milder early toxicity, which will provide a great possibility for future applications. Additionally, no major off-target effects were observed in human cell models, highlighting the targeting specificity of this approach and the potential safety for translation. These findings confirm and extend the therapeutic potential of scAAVrh10-U7-hSOD1 gene therapy while emphasizing the need for further technological development to minimize adverse effects and maximize potential clinical benefit.

pharmacology and toxicology↗

CSF1R regulates monocyte subset differentiation and intracellular metabolism.

Monocytes are key circulating effectors of vascular homeostasis, innate immunity and inflammation. Following their generation in mouse bone marrow, classical (Ly6Chigh) monocytes are mobilized into the blood circulation where they mature into non-classical (Ly6Clow) patrolling monocytes or are recruited into peripheral tissues where they differentiate into tissue resident or inflammatory macrophages. Monocytes and macrophages express CSF1R (CD115), the receptor for lineage-specific growth factors CSF1 and IL34. Here, we report that acute CSF1R blockade or genetic deletion negatively interferes with monocyte intracellular metabolism and reduces blood Ly6Clow monocytes in part by blunting differentiation of Ly6Chigh monocytes. Based upon lineage-specific deletion of GFPT1 (Glutamine-Fructose-6-Phosphate Transaminase 1), the hexosamine biosynthetic pathway (HBP) is identified as a novel regulator of CSF1R expression and monocyte subset diversity. Our findings provide new insights into the link between CSF1R signaling, metabolic regulation, and monocyte survival and differentiation.

immunology↗

CD226+ adipose tissue macrophages arise from MDP-derived monocytes and regulate lipid metabolism.

Macrophages are innate immune cells present in all tissues, in which they participate in immune responses and maintenance of tissue homeostasis. They develop either from embryonic precursors or from circulating monocytes, and their origin impacts their functions. We previously observed robust recruitment of monocytes to brown adipose tissue in which they could differentiation into two distinct macrophage subsets identifiable by CD206 or CD226 expression. In the present study, we investigated monocyte differentiation pathways in brown adipose tissue and the function of monocyte-derived macrophages. Fate mapping analysis revealed a low contribution of GMP- and a high contribution of MDP-derived monocytes to the CD226high macrophage subset. Importantly, adoptive transfer experiments demonstrate that MDP- but not GMP-derived monocytes are pre-conditioned to give rise to CD226high macrophages. We found that MDP-derived CD226high macrophages were also present in other tissues including peritoneal cavity, adrenal glands and all adipose depots. CD226high macrophages were regulated by both GM-CSF and CSF1R. Genetic depletion of CD226high macrophages caused increased BAT and plasma triglyceride content. We thus identify CD226high MDP-derived macrophages as a new myeloid cell type conserved across tissues and tied to lipid metabolism homeostasis.

immunology↗

Top-down control of water intake by the endocannabinoid system

Water intake is regulated by neocortical top-down circuits, but their identity and the cellular mechanisms involved are scantly known. Here, we show that endogenous activation of type-1 cannabinoid receptors (CB1) promotes water intake and that endocannabinoid modulation of excitatory projections from the anterior cingulate cortex to the basolateral amygdala is sufficient to guarantee physiological drinking. These data reveal a new circuit involved in the homeostatic control of water intake.

neuroscience↗