Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Mdm2 widens its repertoire

The p53 tumor suppressor protein is a DNA damage responsive transcription factor that affects diverse cellular processes which include transcription, DNA synthesis and repair, cell cycle arrest, senescence and apoptosis. The Mdm2 oncoprotein is a primary regulator of p53, mediating p53 control via ubiquitin-dependent proteasomal degradation. During DNA damage, the interaction between p53 and Mdm2 is reduced, which allows p53 levels to accumulate. p53 activity is tightly controlled and regulated at a multiplicity of levels, and the importance of co-factors that influence p53 activity is becoming increasingly evident. Recent studies have highlighted the role of Mdm2 in the control of p53 co-factors. Thus, Mdm2 targets JMY, a p53 co-factor, for ubiquitin-dependent Mdm2 targets JMY, a p53 co-factor, for ubiquitin-dependent proteasomal degradation and in doing so overcomes the ability of JMY to augment the p53 response. These results define a new functional relationship between control of p53 activity and Mdm2, and suggest that transcription co-factors which facilitate the p53 response are important targets through which Mdm2 mediates its oncogenic activity

The p53 response: Emerging levels of co-factor complexity

DNA damage triggers a checkpoint response that involves a myriad of cellular responses including cell cycle arrest, DNA repair, and apoptosis, and defects in the DNA damage response pathway lead to tumour development [1]. The tumour suppressor protein p53 is a key player in the checkpoint response to DNA damage, and the precise regulation of p53 is critical for both the checkpoint response and the suppression of tumourigenesis. This is highlighted by the fact that the p53 gene is one of the most commonly mutated genes in human cancer; approximately 50% of human cancers contain p53 mutations while the other half are thought to contain alterations in components of the p53 pathway [2]. p53 is a nuclear transcription factor that affects cellular functions which include transcription, DNA synthesis and repair, cell cycle arrest, senescence, and apoptosis [3]. The central region of p53 contains the DNA-binding domain (DBD), the amino (N)-terminal region harbours a transcriptional activation domain together with a polyproline-rich region, and the carboxyl (C)-terminal region contains a regulatory domain which includes a nuclear localisation signal (NLS) and an oligomerisation function [4]. Under normal conditions, p53 is held in a latent inactive state but undergoes a significant increase in protein stability upon exposure to DNA damage. DNA damage stabilises p53 in part via the DNA damage signalling pathway that involves the sensor kinases, including ATM and ATR, and effector kinases, like Chk1 and Chk2, which leads to the transcriptional regulation of a variety of genes involved in cell cycle control and apoptosis [1] and [4]. Since the activation of p53 causes cell cycle arrest and apoptosis, aberrant activation of p53 would have dire consequences for an organism. p53 is therefore tightly controlled, and its activity is regulated at a multiplicity of levels. Whilst post-translational modification plays an important role in p53 regulation [5], an increasing array of co-factors are now known to influence p53 activity. Here, we will discuss our current understanding of the emerging co-factor complexity involved in regulating the p53 response

Characterisation of chicken TES and its role in cell spreading and motility

Previously we identified TES as a candidate tumour suppressor gene that is located at human chromosome 7q31.1. More recently, we and others have shown TES to encode a novel LIM domain protein that localises to focal adhesions. Here, we present the cloning and functional analysis of the chicken orthologue of TES, cTES. The TES proteins are highly conserved between chicken and human, showing 89% identity at the amino acid level. We show that the cTES protein localised at focal adhesions, actin stress fibres, and sites of cell-cell contact, and GST-cTES can pull-down zyxin and actin. To investigate a functional role for cTES, we looked at the effect of its overexpression on cell spreading and cell motility. Cells overexpressing cTES showed increased cell spreading on fibronectin, and decreased cell motility, compared to RCAS vector transfected control cells. The data from our studies with cTES support our previous findings with human TES and further implicate TES as a member of a complex of proteins that function together to regulate cell adhesion and additionally demonstrate a role for TES in cell motility

TES is a novel focal adhesion protein with a role in cell spreading

Previously, we identified TES as a novel candidate tumour suppressor gene that mapped to human chromosome 7q31.1. In this report we demonstrate that the TES protein is localised at focal adhesions, actin stress fibres and areas of cell-cell contact. TES has three C-terminal LIM domains that appear to be important for focal adhesion targeting. Additionally, the N-terminal region is important for targeting TES to actin stress fibres. Yeast two-hybrid and biochemical analyses yielded interactions with several focal adhesion and/or cytoskeletal proteins including mena, zyxin and talin. The fact that TES localises to regions of cell adhesion suggests that it functions in events related to cell motility and adhesion. In support of this, we demonstrate that fibroblasts stably overexpressing TES have an increased ability to spread on fibronectin

Early stroke risk and ABCD2 score performance in tissue- vs time-defined TIA: A multicenter study

OBJECTIVES: Stroke risk immediately after TIA defined by time-based criteria is high, and prognostic scores (ABCD2 and ABCD3-I) have been developed to assist management. The American Stroke Association has proposed changing the criteria for the distinction between TIA and stroke from time-based to tissue-based. Research using these definitions is lacking. In a multicenter observational cohort study, we have investigated prognosis and performance of the ABCD2 score in TIA, subcategorized as tissue-positive or tissue-negative on diffusion-weighted imaging (DWI) or CT imaging according to the newly proposed criteria. METHODS: Twelve centers provided data on ABCD2 scores, DWI or CT brain imaging, and follow-up in cohorts of patients with TIA diagnosed by time-based criteria. Stroke rates at 7 and 90 days were studied in relation to tissue-positive or tissue-negative subcategorization, according to the presence or absence of brain infarction. The predictive power of the ABCD2 score was determined using area under receiver operator characteristic curve (AUC) analyses. RESULTS: A total of 4,574 patients were included. Among DWI patients (n = 3,206), recurrent stroke rates at 7 days were 7.1%(95% confidence interval 5.5-9.1) after tissue-positive and 0.4% (0.2-0.7) after tissue-negative events (p diff < 0.0001). Corresponding rates in CT-imaged patients were 12.8% (9.3-17.4) and 3.0% (2.0-4.2), respectively (p diff < 0.0001). The ABCD2 score had predictive value in tissue-positive and tissue-negative events (AUC = 0.68 [95% confidence interval 0.63-0.73] and 0.73 [0.67-0.80], respectively; p sig < 0.0001 for both results, p diff = 0.17). Tissue-positive events with low ABCD2 scores and tissue-negative events with high ABCD2 scores had similar stroke risks, especially after a 90-day follow-up. CONCLUSIONS: Our findings support the concept of a tissue-based definition of TIA and stroke, at least on prognostic grounds

Systemic infection of petunia by mechanical inoculation with tomato golden mosaic virus

Aangetoond werd dat Petunia hybrida systemisch kan worden geïnfecteerd met het 'tomato golden mosaic virus' (TGMV), een virus dat behoort tot de groep van de geminivirussen. Mechanische inoculatie van petuniaplanten met TGMV gaf in de systemisch geïnfecteerde bladeren symptomen, die eerder in een aantal andere Solanaceae waren waargenomen. Daar in eerdere proeven petunia niet met TGMV kon worden geïnfecteerd en DNA-replicatie en symptoomontwikkeling wel optrad in, voor de beide genomen van het virus, transgene planten, werd gesuggereerd dat het hier een geval betrof van uitbreiding van de waardplantenreeks. De hier gepresenteerde resultaten kunnen echter tot andere conclusies leiden. Het is namelijk mogelijk, dat bepaalde F-hybriden van petunia resistenter zijn tegen het virus. Verschillen in de symptoomontwikkeling zijn echter ook niet uit te sluiten en zouden veroorzaakt kunnen worden door premunitie als gevolg van de aanwezigheid van het manteleiwit in opnieuw geïnfecteerde cellen.Peer reviewe