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

Proteomic analysis reveals differentially expressed proteins in the rat frontal cortex after methamphetamine treatment

Methamphetamine (MA) is an addictive psycho-stimulant and the illicit use of the drug is escalating. In the present study, we examined protein expression profiles in the rat frontal cortex exposed to a total of eight MA injections (1 mg/kg, intraperitoneal) using 2-DE based proteomics. We investigated protein changes occurring in both the cytosolic fraction and the membrane fraction. 2-DE analysis resulted in 62 cytosolic and 44 membrane protein spots that were differentially regulated in the frontal cortex of rats exposed to MA when compared to control animals. Of these spots, 47 cytosolic and 42 membrane proteins were identified respectively, using ESI-Quad-TOF, which included ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCH-L1), β-synuclein, 78 kDa glucose-regulated protein (GRP 78), γ-enolase, dihydropyrimidase- related protein 2 (DRP 2), complexin 2 and synapsin II. These proteins are associated with protein degradation, redox regulation, energy metabolism, cellular growth, cytoskeletal modifications and synaptic function. Proteomic research may be useful in exploring the complex underlying molecular mechanisms of MA dependence. © 2009 Springer Science+Business Media, LLC.Articl

Early maternal separation followed by later stressors leads to dysregulation of the HPA-axis and increases in hippocampal NGF and NT-3 levels in a rat model.

Early adverse life events, followed by subsequent stressors, appear to increase susceptibility for subsequent onset of psychiatric disorders in humans. The molecular mechanisms that underlie this phenomenon remain unclear, but dysregulation of the HPA axis and alterations in neurotrophic factors have been implicated. The present study investigated the effects in rodents of early maternal separation, followed by stress in adolescence and adulthood on later HPA-axis activity and hippocampal neurotrophin levels (brain-derived neurotrophic factor, nerve growth factor, and neurotrophin-3). Animals subjected to repeated stressors showed a significant decrease in basal ACTH (p < 0.05) and CORT (p < 0.05) levels when compared to controls, as well as significantly increased levels of NGF in the dorsal (p < 0.001) and ventral hippocampus (p < 0.01), and of NT-3 in the dorsal hippocampus (p < 0.01). Dysregulation of the HPA axis after multiple stressors is consistent with previous preclinical and clinical work. Given that neurotrophins are important in neuronal survival and plasticity, it is possible to speculate that their elevation reflects a compensatory mechanism.Articl