Nanomaterials to target defenses

The goal of this review is to evaluate recent advances in understanding the pivotal roles of Cullin-3 (CUL3) in blood pressure regulation with a focus on its actions in the kidney and blood vessels.
Cul3-based ubiquitin ligase regulates renal electrolyte transport, vascular tone, and redox homeostasis by facilitating the normal turnover of (1) with-no-lysine kinases in the distal nephron, (2) RhoA and phosphodiesterase 5 in the vascular smooth muscle, and (3) nuclear factor E2-related factor 2 in antioxidant responses. CUL3 mutations identified in familial hyperkalemic hypertension (FHHt) yield a mutant protein lacking exon 9 (CUL3∆9) which displays dual gain and loss of function. CUL3∆9 acts in a dominant manner to impair CUL3-mediated substrate ubiquitylation and degradation. The consequent accumulation of substrates and overactivation of downstream signaling cause FHHt through increased sodium reabsorption, enhanced vasoconstriction, and decreased vasodilation. CUL3 ubiquitin ligase maintains normal caing cause FHHt through increased sodium reabsorption, enhanced vasoconstriction, and decreased vasodilation. CUL3 ubiquitin ligase maintains normal cardiovascular and renal physiology through posttranslational modification of key substrates which regulate blood pressure. Interference with CUL3 disturbs these key downstream pathways. Further understanding the spatial and temporal specificity of how CUL3 functions in these pathways is necessary to identify novel therapeutic targets for hypertension.
Angiotensin-converting enzyme 2 (ACE2), a specific high-affinity angiotensin II-hydrolytic enzyme, is the vector that facilitates cellular entry of SARS-CoV-1 and the novel SARS-CoV-2 coronavirus. SARS-CoV-2, which crossed species barriers to infect humans, is highly contagious and associated with high lethality due to multi-organ failure, mostly in older patients with other co-morbidities.
Accumulating clinical evidence demonstrates that the intensity of the infection and its complications are more prominent in men. click here It has been postulated that potential functional modulation of ACE2 by estrogen may explain the sex difference in morbidity and mortality. We review here the evidence regarding the role of estrogenic hormones in ACE2 expression and regulation, with the intent of bringing to the forefront potential mechanisms that may explain sex differences in SARS-CoV-2 infection and COVID-19 outcomes, assist in management of COVID-19, and uncover new therapeutic strategies.
Accumulating clinical evidence demonstrates that the intensity of the infection and its complications are more prominent in men. It has been postulated that potential functional modulation of ACE2 by estrogen may explain the sex difference in morbidity and mortality. We review here the evidence regarding the role of estrogenic hormones in ACE2 expression and regulation, with the intent of bringing to the forefront potential mechanisms that may explain sex differences in SARS-CoV-2 infection and COVID-19 outcomes, assist in management of COVID-19, and uncover new therapeutic strategies.
Covid-19 infection poses a serious challenge for immune-compromised patients with inflammatory autoimmune systemic diseases. We investigated the clinical-epidemiological findings of 1641 autoimmune systemic disease Italian patients during the Covid-19 pandemic.
This observational multicenter study included 1641 unselected patients with autoimmune systemic diseases from three Italian geographical areas with different prevalence of Covid-19 [high in north (Emilia Romagna), medium in central (Tuscany), and low in south (Calabria)] by means of telephone 6-week survey. Covid-19 was classified as (1) definite diagnosis of Covid-19 disease presence of symptomatic Covid-19 infection, confirmed by positive oral/nasopharyngeal swabs; (2) highly suspected Covid-19 disease presence of highly suggestive symptoms, in absence of a swab test.
A significantly higher prevalence of patients with definite diagnosis of Covid-19 disease, or with highly suspected Covid-19 disease, or both the conditions together, was observedthe generally mild Covid-19 disease manifestations, and the limited availability of virological testing. • Patients with "connective tissue diseases" show a significantly higher prevalence of Covid-19, possibly due to deeper immune-system impairment, with respect to "inflammatory arthritis group". • Covid-19 is more frequent in the subgroup of autoimmune systemic diseases patients without ongoing conventional synthetic disease-modifying anti-rheumatic drugs, mainly hydroxyl-chloroquine and methotrexate, which might play some protective role against the most harmful manifestations of Covid-19.Phospholipases are important probes for understanding structure-function relationships of membrane proteins. Many neurotoxins have phospholipase activity, and they have been recognized to be potential therapeutic agents for biological warfare. Understanding the modes of action of these enzymes is important for the development of effective therapeutic strategies. Human secretory phospholipases A2 (sPLA2) interact with cellular membranes and catalyze the hydrolysis of phosphate ester bonds of phospholipids. The activity of these enzymes increases tremendously upon binding to a hydrophobic interface. Using molecular dynamics (MD) simulations in implicit solvent and membrane environments, we investigated alterations in structure and conformation of human sPLA2 upon its interaction with a membrane that may be associated with the activation of the enzyme. In 50 ns MD simulations, starting from six different initial orientations of the protein relative to the membrane surface, the enzyme consistently adopted a membrane-bound configuration in close agreement with the known experimental data. The simulations also reproduced the experimentally determined distribution of hydrophobic and polar side chains on the interfacial binding surface. Differences in the dynamic behavior of the enzyme between the solvent and membrane-bound states were observed. In nonpolar media, the enzyme underwent major conformational rearrangements, which exposed the active site to the membrane. The increased mobility of the surface loop and the β-wing regions is required for the conformational change, which is essentially induced by the movement of N-terminal helix. Several active site residues underwent structural changes that reorganize the binding site for substrate catalysis. Overall, the results provided a valuable insight into the interfacial behavior of sPLA2 enzyme and suggested that membrane binding is essential but insufficient for sPLA2 activation.