Pictolysin-III, a Hemorrhagic Type-III Metalloproteinase Isolated from Bothrops pictus (Serpentes: Viperidae) Venom, Reduces Mitochondrial Respiration and Induces Cytokine Secretion in Epithelial and Stromal Cell Lines

From the venom of the Bothrops pictus snake, an endemic species from Peru, we recently have described toxins that inhibited platelet aggregation and cancer cell migration. In this work, we characterize a novel P-III class snake venom metalloproteinase, called pictolysin-III (Pic-III). It is a 62 kDa proteinase that hydrolyzes dimethyl casein, azocasein, gelatin, fibrinogen, and fibrin. The cations Mg2+ and Ca2+ enhanced its enzymatic activity, whereas Zn2+ inhibited it. In addition, EDTA and marimastat were also effective inhibitors. The amino acid sequence deduced from cDNA shows a multidomain structure that includes a proprotein, metalloproteinase, disintegrin-like, and cysteine-rich domains. Additionally, Pic-III reduces the convulxin- and thrombin-stimulated platelet aggregation and in vivo, it has hemorrhagic activity (DHM = 0.3 µg). In epithelial cell lines (MDA-MB-231 and Caco-2) and RMF-621 fibroblast, it triggers morphological changes that are accompanied by a decrease in mitochondrial respiration, glycolysis, and ATP levels, and an increase in NAD(P)H, mitochondrial ROS, and cytokine secretion. Moreover, Pic-III sensitizes to the cytotoxic BH3 mimetic drug ABT-199 (Venetoclax) in MDA-MB-231 cells. To our knowledge, Pic-III is the first SVMP reported with action on mitochondrial bioenergetics and may offer novel opportunities for promising lead compounds that inhibit platelet aggregation or ECM–cancer-cell interactions.</p

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Efecto protector de la melatonina y del tratamiento tópico con la mezcla eutéctica de lidocaína y prilocaína en un modelo de isquemia reperfusión en el colgajo cutáneo microvascularizado en ratas Protective effect of melatonin and the lidocaine and prilocaine eutectic mixture in an ischemia reperfusion injury model in the microvascular cutaneous flap in rats

El síndrome de isquemia reperfusión es el conjunto de sucesos desarrollados desde la instauración de la isquemia en un tejido hasta su posterior reperfusión. Se trata de una condición limitante y, hasta la fecha, inevitable, en toda cirugía que implique una revascularización tisular. En un intento por buscar medidas terapéuticas frente al estrés oxidativo desarrollado durante este síndrome en los colgajos microvascularizados, se valoró la acción del antioxidante melatonina y de los anestésicos locales lidocaína y prilocaína en un modelo de isquemia reperfusión en el colgajo epigástrico microvascularizado en ratas. Tanto el indol como los fármacos vasoactivos poseen un efecto protector en el tratamiento del síndrome de isquemia reperfusión, desde un punto de vista bioquímico e histológico, destacando su acción sinérgica manifestada principalmente como un incremento en la neovascularización tisular.<br>Ischemia-reperfusion injury is a set of events developed since the introduction of ischemia in a tissue to subsequent reperfusion. It is a limiting condition and, to date, inevitable in any surgery involving tissue revascularization. In an attempt to find therapeutic measures against oxidative stress developed during this syndrome in microvascular flaps, we evaluated the antioxidant action of melatonin and local anesthetics lidocaine and prilocaine in a model of ischemia reperfusion in the microvascularized epigastric flap in rats. The indole and vasoactive drugs have a protective effect in the treatment of ischemia reperfusion injury, from both a biochemical and histological view, emphasizing their synergistic action mainly manifested as an increase in tissue neovascularization