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Patients with Skraban‐Deardorff syndrome (SKDEAS), a neurodevelopmental syndrome associated with a spectrum of developmental and intellectual delays and disabilities, harbor diverse mutations in WDR26, encoding a subunit of the multiprotein CTLH E3 ubiquitin ligase complex. Structural studies revealed that homodimers of WDR26 bridge two core‐CTLH E3 complexes to generate giant, hollow oval‐shaped supramolecular CTLH E3 assemblies. Additionally, WDR26 mediates CTLH E3 complex binding to subunit YPEL5 and functions as substrate receptor for the transcriptional repressor HBP1. Here, we mapped SKDEAS‐associated mutations on a WDR26 structural model and tested their functionality in complementation studies using genetically engineered human cells lacking CTLH E3 supramolecular assemblies. Despite the diversity of mutations, 15 of 16 tested mutants impaired at least one CTLH E3 complex function contributing to complex assembly and interactions, thus providing first mechanistic insights into SKDEAS pathology. [ABSTRACT FROM AUTHOR]

In view of emerging drug-resistant tuberculosis (TB), host-directed adjunct therapies are urgently needed to improve treatment outcomes with currently available anti-TB therapies. One approach is to interfere with the formation of lipid-laden 'foamy' macrophages in the host, as they provide a nutrient-rich host cell environment for Mycobacterium tuberculosis (Mtb). Here, we provide evidence that Wnt family member 6 (WNT6), a ligand of the evolutionarily conserved Wingless/Integrase 1 (WNT) signaling pathway, promotes foam cell formation by regulating key lipid metabolic genes including acetylCoA carboxylase 2 (ACC2) during pulmonary TB. Using genetic and pharmacological approaches, we demonstrated that lack of functional WNT6 or ACC2 significantly reduced intracellular triacylglycerol (TAG) levels and Mtb survival in macrophages. Moreover, treatment of Mtb-infected mice with a combination of a pharmacological ACC2 inhibitor and the anti-TB drug isoniazid (INH) reduced lung TAG and cytokine levels, as well as lung weights, compared with treatment with INH alone. This combination also reduced Mtb bacterial numbers and the size of mononuclear cell infiltrates in livers of infected mice. In summary, our findings demonstrate that Mtb exploits WNT6/ACC2-induced storage of TAGs in macrophages to facilitate its intracellular survival, a finding that opens new perspectives for host-directed adjunctive treatment of pulmonary TB., Introduction Tuberculosis (TB) is the leading cause of death from a single bacterial agent (1). The current increase in numbers of patients affected by multidrug-resistant and rifampicin-resistant TB (2) severely [...]

Gepotidacin is a novel, bactericidal, first‐in‐class triazaacenaphthylene antibiotic in late‐phase development for uncomplicated urinary tract infection and uncomplicated urogenital gonorrhea. Two clinical studies were conducted to assess the pharmacokinetics (PK) and interethnic comparisons of oral gepotidacin (free‐base and to‐be‐marketed mesylate formulations) administered as single doses ranging from 1500 to 3000 mg in fed and fasted states, and as 2 × 3000‐mg doses given 12 hours apart under fed conditions in healthy participants of Japanese ancestry. Dose proportionality was observed in plasma exposures, and comparable area under the concentration‐time curve (AUC) and maximum concentration were observed in fed and fasted states. Interethnic comparisons for Japanese versus non‐Japanese participant data showed slightly higher plasma maximum concentration (7%‐30%) yet similar plasma AUCs; slightly lower urine AUCs (11%‐18%) were observed. The slightly higher plasma exposures in healthy Japanese versus White participants in the same study were attributed to lower mean body weights (64 kg versus ≈80 kg). Adverse events were primarily gastrointestinal, and when administered with food, gastrointestinal tolerability was improved. Overall, the gepotidacin PK and safety‐risk profiles in healthy Japanese support potential evaluation of the global clinical doses in future studies. [ABSTRACT FROM AUTHOR]

Aims: This study implements a physiologically‐based pharmacokinetic (PBPK) modelling approach to investigate inter‐ethnic differences in imatinib pharmacokinetics and dosing regimens. Methods: A PBPK model of imatinib was built in the Simcyp Simulator (version 17) integrating in vitro drug metabolism and clinical pharmacokinetic data. The model accounts for ethnic differences in body size and abundance of drug‐metabolising enzymes and proteins involved in imatinib disposition. Utility of this model for prediction of imatinib pharmacokinetics was evaluated across different dosing regimens and ethnic groups. The impact of ethnicity on imatinib dosing was then assessed based on the established range of trough concentrations (Css,min). Results: The PBPK model of imatinib demonstrated excellent predictive performance in describing pharmacokinetics and the attained Css,min in patients from different ethnic groups, shown by prediction differences that were within 1.25‐fold of the clinically‐reported values in published studies. PBPK simulation suggested a similar dose of imatinib (400–600 mg/d) to achieve the desirable range of Css,min (1000–3200 ng/mL) in populations of European, Japanese and Chinese ancestry. The simulation indicated that patients of African ancestry may benefit from a higher initial dose (600–800 mg/d) to achieve imatinib target concentrations, due to a higher apparent clearance (CL/F) of imatinib compared to other ethnic groups; however, the clinical data to support this are currently limited. Conclusion: PBPK simulations highlighted a potential ethnic difference in the recommended initial dose of imatinib between populations of European and African ancestry, but not populations of Chinese and Japanese ancestry. [ABSTRACT FROM AUTHOR]