Biology subjects

Poletti, V.

Publications and source records attributed to Poletti, V..

3 recordsLinked to original sources

bioRxiv2026

Alveolar niche disruption and aberrant epithelial reprogramming are early hallmarks of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease in which the earliest cellular events driving fibrosis remain poorly defined. Here, we analyzed lung samples from three independent and unique cohorts of patients with early disease and preserved lung function (Florence, NIH, Forli), applying an integrated multi-modal approach combining single-nucleus RNA sequencing, bulk transcriptomics, immunostaining, and spatial transcriptomics. Single nuclear RNA sequencing of samples obtained by diagnostic bronchoscopic cryobiopsy (Florence, n= 22) revealed that early IPF is characterized by a marked shift in alveolar epithelial composition, with loss of AT1 and AT2 cells and the emergence of aberrant basaloid cells and alveolar epithelial intermediate cells. These populations exhibited transcriptional programs associated with epithelial plasticity and profibrotic signaling and closely resembled those observed in end-stage IPF. Higher proportions of aberrant basaloid and alveolar epithelial intermediate cells were associated with subsequent disease progression, whereas AT2 cell abundance correlated with preserved lung function. Fibrotic CTHRC1+ fibroblasts are largely restricted to advanced disease, while endothelial remodeling and inflammatory fibroblast states are already evident in early IPF. Spatial transcriptomic analyses confirmed early disruption of the alveolar niche, with replacement of normal epithelial-capillary interactions by aberrant epithelial and venous endothelial cells (Forli, n= 24); the findings were replicated through single cell RNA sequencing of samples obtained by video assisted thoracoscopy two decades earlier (NIH n=9). Together, these findings identify that alveolar niche remodeling with loss of its normal components, and emergence of aberrant basaloid cells are features of early IPF, highlighting epithelial dysfunction as a key potential target for therapeutic interventions in early disease.

genomics↗

bioRxiv2022

Novel lentiviral vectors for gene therapy of sickle cell disease combining gene addition and gene silencing strategies

Sickle cell disease (SCD) is due to a mutation in the {beta}-globin (HBB) gene causing the production of the toxic sickle hemoglobin (HbS, a2{beta}S2). Transplantation of autologous hematopoietic stem/progenitor cells (HSPCs) transduced with lentiviral vectors (LVs) expressing an anti-sickling {beta}-globin ({beta}AS) is a promising treatment; however, it is only partially effective and patients still present elevated HbS levels. Here, we developed a bifunctional LV expressing {beta}AS3-globin and an artificial microRNA (amiR) specifically downregulating {beta}S-globin expression with the aim of reducing HbS levels and favoring {beta}AS3 incorporation into Hb tetramers. Efficient transduction of SCD HSPC by the bifunctional LV led to a substantial decrease of {beta}S-globin transcripts in HSPC-derived erythroid cells, a significant reduction of HbS+ red cells and effective correction of the sickling phenotype, outperforming {beta}AS gene addition and BCL11A gene silencing strategies. The bifunctional LV showed a standard integration profile and neither the HSPC viability, engraftment and multi-lineage differentiation nor the erythroid transcriptome and miRNAome were affected by the treatment, confirming the safety of this therapeutic strategy. In conclusion, the combination of gene addition and gene silencing strategies can improve the efficacy of current LV-based therapeutic approaches without increasing the mutagenic vector load, thus representing a novel treatment for SCD.

genetics↗

bioRxiv2022

An innovative hematopoietic stem cell gene therapy approach benefits CLN1 disease in the mouse model

Hematopoietic stem and progenitor cells (HSPCs) can lead to the establishment of a long-lasting microglia-like progeny in the brain of properly myeloablated hosts. We exploited this approach to treat the severe CLN1 neurodegenerative disorder, which is the most aggressive form of neuronal ceroid lipofuscinoses, due to deficiency of palmitoyl-protein thioesterase 1 (hPPT1). We here provide first evidence that: i) transplantation of wild type HSPCs exerts a partial but long-lasting mitigation of the symptoms; ii) transplantation of HSPCs over-expressing hPPT1 by lentiviral gene transfer enhances therapeutic benefit as compared to wild type cell transplant, with first demonstration of such a dose-effect benefit for a purely neurodegenerative condition like CLN1 disease; iii) transplantation of hPPT1 over-expressing HSPCs by a novel intracerebroventricular (ICV) approach is sufficient to transiently ameliorate CLN1 disease symptomatology in the absence of hematopoietic tissue engraftment of the transduced cells; and iv) the combinatorial transplantation of transduced HSPCs intravenously and ICV results in the most robust therapeutic benefit among the tested approaches on both pre-symptomatic as well as symptomatic animals. Overall, these findings provide first evidence of the efficacy and feasibility of this novel approach to treat CLN1 disease and possibly other neurodegenerative conditions, paving the way for its future clinical application.

neuroscience↗