SARS-CoV-2, the causative agent of the ongoing COVID-19, has spread worldwide since it was first identified in November 2019 in Wuhan. Since then, it was already demonstrated an exuberant inflammation, cytokine storm, endothelium dysfunction, platelets hyperactivation and aggregation, following T cell exhaustion leading to severe multi-organ damage and death of COVID-19 patients. Here, we sought to identify molecular biomarkers of disease severity in a Brazilian cohort of COVID-19 patients by measuring the serum levels of endogenous danger signals. Our data revealed that ICU patients that are critically ill, at the early hyperinflammatory phase of COVID-19 (around 12-25 days after hospital admission) display higher serum levels of the classical alarmin HMGB1. Serum levels of HMGB1 were positively correlated with cys-leukotrienes, D-dimer, AST, and ALT. Notably, we verified that HMGB1 levels above 125.4 ng/mL is the cut off that distinguishes the patients that are at higher risk of death. Serum levels of extracellular ATP, PGE<2, LTB4, cys-LTs, and tissue factor were also elevated in the serum of ICU patients. In conclusion, we propose that serum levels of HMGB1 serve as prognostic biomarker of risk of death in patients suffering from severe COVID-19.

Homeobox genes encode transcriptional factors, usually involved in molecular control of plant developmental patterns. They can be divided into several classes according to conserved sequences within the homeobox region and the presence of specific additional sequences. Based on these conserved sequences, we developed a search procedure to identify possible homeobox genes in the Eucalyptus Genome Sequencing Project Consortium (FORESTs) database. We were able to identify 50 Eucalyptus sequences (EST-contigs) containing the homeodomain sequence. Phylogenetic analysis was applied to this ESTs-contigs and 44 of them were found to have similarities with one of three well-known homeobox classes: Bell, Knox and HD-Zip, and their sub-classes. However, no EST-contig grouped with the fourth important homeobox class, the PHD-finger homeobox. On the other hand, two sequences have showed pronounced similarity to the Arabidopsis thaliana Wuschel gene, considered an "atypical" homeobox gene. Hierarchical clustering analysis of the expression pattern of these putative Eucalyptus homeobox genes revealed the presence of ten distinct expression groups. Combining phylogenetic analysis and expression patterns for some of the Eucalyptus genes revealed interesting aspects about some of the potential homeobox genes, which might lead to a better understanding of the Eucalyptus biology and to biotechnological applications.

The severe acute respiratory syndrome coronavirus 2, the agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic, has spread worldwide since it was first identified in November 2019 in Wuhan, China. Since then, progress in pathogenesis linked severity of this systemic disease to the hyperactivation of network of cytokine-driven pro-inflammatory cascades. Here, we aimed to identify molecular biomarkers of disease severity by measuring the serum levels of inflammatory mediators in a Brazilian cohort of patients with COVID-19 and healthy controls (HCs). Critically ill patients in the intensive care unit were defined as such by dependence on oxygen supplementation (93% intubated and 7% face mask), and computed tomography profiles showing ground-glass opacity pneumonia associated to and high levels of D-dimer. Our panel of mediators included HMGB1,