Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Structural basis of the potency and selectivity of Urotoxin, a potent Kv1 blocker from scorpion venom

Urotoxin (α-KTx 6), a peptide from venom of the Australian scorpion Urodacus yaschenkoi, is the most potent inhibitor of Kv1.2 described to date (IC50 = 160 pM). The native peptide also inhibits Kv1.1, Kv1.3 and KCa3.1 with nanomolar affinity but its low abundance in venom precluded further studies of its actions. Here we produced recombinant Urotoxin (rUro) and characterized the molecular determinants of Kv1 channel inhibition. The 3D structure of rUro determined using NMR spectroscopy revealed a canonical cysteine-stabilised α/β (CSα/β) fold. Functional assessment of rUro using patch-clamp electrophysiology revealed the importance of C-terminal amidation for potency against Kv1.1-1.3 and Kv1.5. Neutralization of the putative pore-blocking K25 residue in rUro by mutation to Ala resulted in a major decrease in rUro potency against all Kv channels tested, without perturbing the toxin\u27s structure. Reciprocal mutations in the pore of Uro-sensitive Kv1.2 and Uro-resistant Kv1.5 channels revealed a direct interaction between Urotoxin and the Kv channel pore. Our experimental work supports postulating a mechanism of action in which occlusion of the permeation pathway by the K25 residue in Urotoxin is the basis of its Kv1 inhibitory activity. Docking analysis was consistent with occlusion of the pore by K25 and the requirement of a small, non-charged amino acid in the Kv1 channel vestibule to facilitate toxin-channel interactions. Finally, computational studies revealed key interactions between the amidated C-terminus of Urotoxin and a conserved Asp residue in the turret of Kv1 channels, offering a potential rationale for potency differences between native and recombinant Urotoxin

Knockdown of the Drosophila GTPase Nucleostemin 1 Impairs Large Ribosomal Subunit Biogenesis, Cell Growth, and Midgut Precursor Cell Maintenance

Mammalian nucleostemin (NS) is a nucleolar guanosine triphosphate-binding protein implicated in cell cycle progression, stem cell proliferation, and ribosome assembly. Drosophila melanogaster contains a four-member nucleostemin family (NS1–4). NS1 is the closest orthologue to human NS; it shares 33% identity and 67% similarity with human NS. We show that NS1 has intrinsic GTPase and ATPase activity and that it is present within nucleoli of most larval and adult cells. Endogenous NS1 and lightly expressed green fluorescent protein (GFP)-NS1 enrich within the nucleolar granular regions as expected, whereas overexpressed GFP-NS1 localized throughout the nucleolus and nucleoplasm, and to several transcriptionally active interbands of polytene chromosomes. Severe overexpression correlated with the appearance of melanotic tumors and larval/pupal lethality. Depletion of 60% of NS1 transcripts also lead to larval and pupal lethality. NS1 protein depletion>95 correlated with the loss of imaginal island (precursor) cells in the larval midgut and to an apparent block in the nucleolar release of large ribosomal subunits in terminally differentiated larval midgut polyploid cells. Ultrastructural examination of larval Malpighian tubule cells depleted for NS1 showed a loss of cytoplasmic ribosomes and a concomitant appearance of cytoplasmic preautophagosomes and lysosomes. We interpret the appearance of these structures as indicators of cell stress response