Biology subjects

Thornton, N.

Publications and source records attributed to Thornton, N..

3 recordsLinked to original sources

bioRxiv2025

Chlorotonils exhibit potent activity against Mycobacterium tuberculosis, while resistance is mediated by MmpR5-MmpL5

Treatment of Mycobacterium tuberculosis (Mtb) is challenging and requires administration of at least four different antibiotics. Unfortunately, multi-drug resistant Mtb strains continue to emerge, undermining the effectiveness of current treatment regimens and highlighting the urgent need for new therapeutics. In this study, we evaluated the potential of natural product-derived chlorotonils as anti-Mtb agents. We demonstrate that chlorotonils exhibit nanomolar potency against a range of attenuated and virulent Mtb strains. Mechanistic studies and resistance profiling in Mtb revealed that chlorotonils affect both lipid and energy metabolism. Through systems biology approaches, including the construction of an Mtb CRISPRi library specifically designed for chemical-genomic profiling, we identified MmpR5/MmpL5 as major driver of chlorotonil-resistance in Mtb leading also to cross-resistance with bedaquiline. Our findings highlight chlorotonils as valuable chemical tools to further dissect the role and function of the MmpS5-MmpL5 efflux pump in drug-resistant Mtb.

microbiology↗

bioRxiv2025

Development of a Clinically Relevant Rabbit Model of Acute Laryngeal Injury

ObjectivesAcute Laryngeal Injury (ALgI) is created as a result of endotracheal tube pressure ulcer formation leading to fibrosis and inflammation. This condition often leads to airway obstruction and voice and swallowing dysfunction. This study demonstrates a reliable animal model of ALgI to reproduce the acute wound process seen clinically, to explore the pathophysiology of this disease process, and serve as a reproducible injury suitable for the evaluation of therapeutic interventions. MethodsAn ALgI model was developed in New Zealand White rabbits using precise mucosal stripping of the posterior larynx, followed by intubation with an oversized 4.0 endotracheal tube for one hour to mimic intubation-associated trauma and pressure ischemia. Laryngoscopy and laryngeal harvest were performed two weeks post-injury for histologic and immunofluorescent evaluation. ResultsInjured rabbits demonstrated an eight-fold increase in posterior glottic thickness (1.57mm vs. 0.19mm in controls; p=0.0004) and eleven-fold increase in collagen content (1.93mm2 vs. 0.17mm2; p=0.005). Collagen subtype analysis revealed a shift toward active collagen within the injured larynx compared to the uninjured, with increased type III collagen (69.0%% vs. 26.1%; p<0.0001) and reduced type I collagen (27.2% vs. 73.9%; p<0.0001) in the posterior glottis, consistent with the proliferative phase of wound healing. Collagen fiber alignment analysis demonstrated increased coherency in injured tissues (0.36 vs. 0.21; p=0.023), indicating early organized collagen formation consistent with scar formation within the posterior glottis. ConclusionsThe model offers a robust platform for studying the acute pathogenesis of laryngeal injury and for testing the treatment options in the management of ALgI. Level of EvidenceLevel III

bioengineering↗

bioRxiv2016

A structural variant encoding hybrid glycophorins is associated with resistance to severe malaria

Plasmodium falciparum invades human red blood cells by a series of interactions between host and parasite surface proteins. Here we analyse whole genome sequence data from worldwide human populations, including 765 new genomes from across sub-Saharan Africa, and identify a diverse array of large copy number variants affecting the host invasion receptor genes GYPA and GYPB. We find that a nearby reported association with severe malaria is explained by a complex structural variant that involves the loss of GYPB and gain of two hybrid genes, each with a GYPB extracellular domain and GYPA intracellular domain. This variant reduces the risk of severe malaria by 40% and has recently risen in frequency in parts of Kenya. We show that the structural variant encodes the Dantu blood group antigen, and therefore a serologically distinct red cell phenotype. These findings demonstrate that structural variation of red blood cell invasion receptors is associated with natural resistance to P. falciparum malaria.

genomics↗