Dermatologic Changes in Experimental Model of Long COVID.

The coronavirus disease-19 (COVID-19) pandemic, declared in early 2020, has left an indelible mark on global health, with over 7.0 million deaths and persistent challenges. While the pharmaceutical industry raced to develop vaccines, the emergence of mutant severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) strains continues to pose a significant threat. Beyond the immediate concerns, the long-term health repercussions of COVID-19 survivors are garnering attention, particularly due to documented cases of cardiovascular issues, liver dysfunction, pulmonary complications, kidney impairments, and notable neurocognitive deficits. Recent studies have delved into the pathophysiological changes in various organs following post-acute infection with murine hepatitis virus-1 (MHV-1), a coronavirus, in mice. One aspect that stands out is the impact on the skin, a previously underexplored facet of long-term COVID-19 effects. The research reveals significant cutaneous findings during both the acute and long-term phases post-MHV-1 infection, mirroring certain alterations observed in humans post-SARS-CoV-2 infection. In the acute stages, mice exhibited destruction of the epidermal layer, increased hair follicles, extensive collagen deposition in the dermal layer, and hyperplasticity of sebaceous glands. Moreover, the thinning of the panniculus carnosus and adventitial layer was noted, consistent with human studies. A long-term investigation revealed the absence of hair follicles, destruction of adipose tissues, and further damage to the epidermal layer. Remarkably, treatment with a synthetic peptide, SPIKENET (SPK), designed to prevent Spike glycoprotein-1 binding with host receptors and elicit a potent anti-inflammatory response, showed protection against MHV-1 infection. Precisely, SPK treatment restored hair follicle loss in MHV-1 infection, re-architected the epidermal and dermal layers, and successfully overhauled fatty tissue destruction. These promising findings underscore the potential of SPK as a therapeutic intervention to prevent long-term skin alterations initiated by SARS-CoV-2, providing a glimmer of hope in the battle against the lingering effects of the pandemic.

Laccase Engineering: Redox Potential Is Not the Only Activity-Determining Feature in the Metalloproteins.

Laccase, one of the metalloproteins, belongs to the multicopper oxidase family. It oxidizes a wide range of substrates and generates water as a sole by-product. The engineering of laccase is important to broaden their industrial and environmental applications. The general assumption is that the low redox potential of laccases is the principal obstacle, as evidenced by their low activity towards certain substrates. Therefore, the primary goal of engineering laccases is to improve their oxidation capability, thereby increasing their redox potential. Even though some of the determinants of laccase are known, it is still not entirely clear how to enhance its redox potential. However, the laccase active site has additional characteristics that regulate the enzymes' activity and specificity. These include the electrostatic and hydrophobic environment of the substrate binding pocket, the steric effect at the substrate binding site, and the orientation of the binding substrate with respect to the T1 site of the laccase. In this review, these features of the substrate binding site will be discussed to highlight their importance as a target for future laccase engineering.

Recent advances in the role of neutrophils and neutrophil extracellular traps in acute pancreatitis.

Pancreatitis is an inflammatory disease, which is triggered by adverse events in acinar cells of the pancreas. After the initial injury, infiltration of neutrophils in pancreas is observed. In the initial stages of pancreatitis, the inflammation is sterile. It has been shown that the presence of neutrophils at the injury site can modulate the disease. Their depletion in experimental animal models of the acute pancreatitis has been shown to be protective. But information on mechanism of contribution to inflammation by neutrophils at the injury site is not clear. Once at injury site, activated neutrophils release azurophilic granules containing proteolytic enzymes and generate hypochlorous acid which is a strong microbicidal agent. Additionally, emerging evidence shows that neutrophil extracellular traps (NETs) are formed which consist of decondensed DNA decorated with histones, proteases and granular and cytosolic proteins. NETs are considered mechanical traps for microbes, but there is preliminary evidence to indicate that NETs, which constitute a special mechanism of the neutrophil defence system, play an adverse role in pancreatitis by contributing to the pancreatic inflammation and distant organ injury. This review presents the overall current information about neutrophils and their role including NETs in acute pancreatitis (AP). It also highlights current gaps in knowledge which should be explored to fully elucidate the role of neutrophils in AP and for therapeutic gains.

Recent Advances in Repurposing Disulfiram and Disulfiram Derivatives as Copper-Dependent Anticancer Agents.

Copper (Cu) plays a pivotal role in cancer progression by acting as a co-factor that regulates the activity of many enzymes and structural proteins in cancer cells. Therefore, Cu-based complexes have been investigated as novel anticancer metallodrugs and are considered as a complementary strategy for currently used platinum agents with undesirable general toxicity. Due to the high failure rate and increased cost of new drugs, there is a global drive towards the repositioning of known drugs for cancer treatment in recent years. Disulfiram (DSF) is a first-line antialcoholism drug used in clinics for more than 65 yr. In combination with Cu, it has shown great potential as an anticancer drug by targeting a wide range of cancers. The reaction between DSF and Cu ions forms a copper diethyldithiocarbamate complex (Cu(DDC)2 also known as CuET) which is the active, potent anticancer ingredient through inhibition of NF-κB and ubiquitin-proteasome system as well as alteration of the intracellular reactive oxygen species (ROS). Importantly, DSF/Cu inhibits several molecular targets related to drug resistance, stemness, angiogenesis and metastasis and is thus considered as a novel strategy for overcoming tumour recurrence and relapse in patients. Despite its excellent anticancer efficacy, DSF has proven unsuccessful in several cancer clinical trials. This is likely due to the poor stability, rapid metabolism and/or short plasma half-life of the currently used oral version of DSF and the inability to form Cu(DDC)2 at relevant concentrations in tumour tissues. Here, we summarize the scientific rationale, molecular targets, and mechanisms of action of DSF/Cu in cancer cells and the outcomes of oral DSF ± Cu in cancer clinical trials. We will focus on the novel insights on harnessing the immune system and hypoxic microenvironment using DSF/Cu complex and discuss the emerging delivery strategies that can overcome the shortcomings of DSF-based anticancer therapies and provide opportunities for translation of DSF/Cu or its Cu(DDC)2 complex into cancer therapeutics.

Enzyme engineering: Reshaping the biocatalytic functions.

Enzyme engineering is a powerful tool to fine-tune the enzymes. It is a technique by which the stability, activity, and specificity of the enzymes can be altered. The characteristic properties of an enzyme can be amended by immobilization and protein engineering. Among them, protein engineering is the most promising, as in addition to amending the stability and activity, it is the only way to modulate the specificity and stereoselectivity of enzymes. The current review sheds light on protein engineering and the approaches applied for it on the basis of the degree of knowledge of structure and function of enzymes. Enzymes, which have been engineered are also discussed in detail and categorized on the basis of their respective applications. This will give a better insight into the revolutionary changes brought by protein engineering of enzymes in various industrial and environmental processes.

Guar gum blended alginate/agarose hydrogel as a promising support for the entrapment of peroxidase: Stability and reusability studies for the treatment of textile effluent.

Ginger peroxidase (GP) was entrapped into the hydrogels of guar gum (GG)-alginate/agarose and these immobilized GP preparations were employed for the treatment of textile effluent. GG is a natural hydrophilic polysaccharide, the average size of which increases in its hydrated form that helps in retaining the enzyme inside the entrapping support. Therefore, the activity retention by alginate-guar gum (ANGG) and agarose-guar gum (AGG) was higher than that of alginate and agarose alone. ANGG-GP and AGG-GP were highly stable against various physical and chemical denaturants during the decolorization of textile effluent. As compared to free GP, both the immobilized preparations were more efficient in the decolorization of textile effluent in batch processes. After 10th repeated use in batch processes, ANGG-GP and AGG-GP was quite effective in removing up to 68% and 55% of the color from textile effluent, respectively. Continuous packed bed reactors containing ANGG-GP and AGG-GP were able to decolorize around 80% and 69% of the effluent color, respectively, even after 30 days of their continuous operation at room temperature (30 °C). Genotoxicity of textile effluent was significantly reduced after GP mediated decolorization.

Immobilization of peroxidase on polypyrrole-cellulose-graphene oxide nanocomposite via non-covalent interactions for the degradation of Reactive Blue 4 dye.

In the present study novel polypyrrole-cellulose-graphene oxide nanocomposite (PCeGONC) was employed for the immobilization of ginger peroxidase (GP) via simple adsorption mechanism. Immobilization of enzyme on the obtained support resulted in enhancement of the enzyme activity. The recovery of activity was 128% of the initial activity. Consequently, in 3 h stirred batch treatment, PCeGONC bound GP exhibited higher decolorization efficiency (99%) for Reactive Blue 4 (RB 4) dye as compared to free GP (88%). The immobilized GP exhibited higher operational stability and retained approximately 72% of its initial activity even after ten sequential cycles of dye decolorization in batch process. The kinetic characterization of PCeGONC bound GP revealed slightly lower Km and 3.3 times higher Vmax compared to free GP. Degraded products were identified on the basis of GC-MS analysis and degradation pathway was proposed accordingly which confirms enzymatic breakdown of RB 4 into low molecular weight compounds. Genotoxic assessment of GP treated RB 4 revealed significant reduction of its genotoxic potential. In-silico analysis identified that binding site of PCeGONC on enzyme is distinct and lies far away from the active site of the enzyme. Furthermore, it also revealed higher affinity of 1-hydroxybenzotriazole (a redox mediator) and RB 4 for PCeGONC bound enzyme as compared to the free enzyme. This is in consensus with the observed decrease in Km of the immobilized GP.