Biology subjects

Mariniello, M.

Publications and source records attributed to Mariniello, M..

3 recordsLinked to original sources

bioRxiv2026

Base Editing as a Therapeutic Strategy for Autosomal Dominant Tubulointerstitial Kidney Disease caused by Pathogenic UMOD Variants

Autosomal dominant tubulointerstitial kidney disease caused by pathogenic UMOD variants (ADTKD-UMOD) is an untreatable monogenic kidney disease in which misfolded uromodulin is retained in the endoplasmic reticulum and exerts a toxic gain-of-function effect. Here we systematically evaluate the full spectrum of base editing strategies targeting the UMOD locus. Base editors corrected a representative missense patient variant, p.Cys170Tyr, with A-to-G conversion efficiencies of up to 83.4%, restoring uromodulin trafficking to the plasmamembrane in cell lines and in human 3D kidney tubuloids. Mutation-agnostic inactivation wasachieved by four routes: premature stop codon introduction, splice-site disruption, allele-specific stop codon introduction and promoter attenuation. Maximum on-target efficienciesranged from 44.1% to 71.9%, providing a strategy set applicable across the UMOD allelicspectrum. Endogenous UMOD expression is rarely recapitulated in human cell models,leaving strategies that act on the endogenous gene difficult to assess in patient cells. Wetherefore established CRISPR activation (CRISPRa) of the endogenous UMOD promoterand confirmed its ability to upregulate UMOD expression in human urine-derived cells. Thisapproach further enabled quantification of endogenous UMOD transcript reduction followingbase editing in HEK293 cells. These results establish base editing as a versatile approachfor ADTKD-UMOD and provide a primary human system for testing interventions targetingendogenous UMOD expression, from nucleic acid-based silencing to small molecules.

genetics↗

bioRxiv2022

Allelic and Gene Dosage Effects Involving Uromodulin Aggregates Drive Autosomal Dominant Tubulointerstitial Kidney Disease

Missense mutations in the UMOD gene encoding uromodulin cause autosomal dominant tubulointerstitial kidney disease (ADTKD), one of the most common monogenic kidney diseases. A pressing need for ADTKD is to bridge the gap between postulated gain-of-function mutations and organ damage - a prerequisite for therapeutic development. Based on two missense UMOD mutations associated with divergent progression of ADTKD, we generated UmodC171Y and UmodR186S knock-in mice that showed strong allelic and gene dosage effects, with distinct dynamic pathways impacting on uromodulin trafficking, formation of intracellular aggregates, activation of ER stress, unfolded protein and immune responses, kidney damage and progression to kidney failure. Deletion of the wild-type Umod allele in heterozygous UmodR186S mice increased the formation of uromodulin aggregates and ER stress, indicating a protective role of wild-type uromodulin. Studies in kidney tubular cells confirmed biochemical differences between distinct uromodulin aggregates, with activation of specific quality control and clearance mechanisms. Enhancement of autophagy by starvation and mTORC1 inhibition decreased the uromodulin aggregates, suggesting a therapeutic strategy. These studies substantiate a model for allelic effects and the role of toxic aggregates in the progression of ADTKD-UMOD, with relevance for toxic gain-of-function mechanisms and for strategies to improve clearance of mutant uromodulin.

genetics↗

bioRxiv2019

Synthetic lethality screening reveals FDA-approved drugs that overcome ATP7B-mediated tolerance of tumor cells to cisplatin

Tumor resistance to chemotherapy represents an important challenge in modern oncology. Although platinum (Pt)-based drugs have demonstrated excellent therapeutic potential, their effectiveness in a wide range of tumors is limited by the development of resistance mechanisms. One of these mechanisms includes increased cisplatin sequestration/efflux by the copper-transporting ATPase, ATP7B. However, targeting ATP7B to reduce Pt tolerance in tumors could represent a serious risk because suppression of ATP7B might compromise copper homeostasis, as happens in Wilson disease.\n\nTo circumvent ATP7B-mediated Pt tolerance we employed a high-throughput screen (HTS) of an FDA/EMA-approved drug library to detect safe therapeutic molecules that promote cisplatin toxicity in the resistant ovarian carcinoma cell line IGROV-CP20. Using a synthetic lethality approach we identified and validated three hits (Tranilast, Telmisartan and Amphotericin B) that could reduce cisplatin resistance. All three drugs induced Pt-mediated DNA damage and inhibited either expression or trafficking of ATP7B in a tumor-specific manner. Global transcriptome analyses showed that Tranilast and Amphotericin B affect expression of genes operating in several pathways that confer tolerance to cisplatin. In the case of Tranilast, these included key molecular players operating in the distribution of platinum to different intracellular compartments. In particular, Tranilast was found to suppress ATOX1 and, as a consequence, ATOX1-mediated trafficking of ATP7B in response to cisplatin.\n\nConsidering the well-known safety profiles of Tranilast, Telmisartan and Amphotericin B, these drugs emerge as potential candidates that might be used for the rapid development of new therapeutic strategies to overcome resistance of tumors to Pt-based chemotherapy.

cancer biology↗