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α -1 antitrypsin (A1AT) is a 52 kDa acute-phase glycoprotein belonging to the serine protease inhibitor superfamily (SERPIN). It is primarily synthesized by hepatocytes and to a lesser extent by monocytes, macrophages, intestinal epithelial cells, and bronchial epithelial cells. A1AT is encoded by SERPINA1 locus, also known as PI locus, highly polymorphic with at least 100 allelic variants described and responsible for different A1AT serum levels and function. A1AT inhibits a variety of serine proteinases, but its main target is represented by Neutrophil Elastase (NE). However, recent attention has been directed towards its immune-regulatory and homeostatic activities. A1AT exerts immune-regulatory effects on different cell types involved in innate and adaptive immunity. Additionally, it plays a role in metal and lipid metabolism, contributing to homeostasis. An adequate comprehension of these mechanisms could support the use of A1AT augmentation therapy in many disorders characterized by a chronic immune response. The aim of this review is to provide an up-to-date understanding of the molecular mechanisms and regulatory pathways responsible for immune-regulatory and homeostatic activities of A1AT. This knowledge aims to support the use of A1AT in therapeutic applications. Furthermore, the review summarizes the current state of knowledge regarding the application of A1AT in clinical and laboratory settings human and animal models. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular disease was the leading cause of death worldwide in 2021, with atherosclerotic cardiovascular disease, encompassing hypercholesterolemia, being a major contributing factor. A range of lipid-lowering medications is used for the management of hyperlipidemia, but the use of statins is considered as standard therapy. Unfortunately, some patients do not respond to this therapy, necessitating novel therapeutic approaches. Tafolecimab is a novel proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibody that inhibits the binding of PCSK9 with low-density lipoprotein receptors (LDLRs) and increases LDLR recycling, and thus it indirectly lowers circulating low-density lipoprotein cholesterol (LDL-C) levels by increasing LDL-C uptake. The primary objective of this study is to assess the efficacy of tafolecimab in reducing LDL-C levels. Methods: A thorough search was conducted on Medline (PubMed), Cochrane CENTRAL, Scopus, and Google Scholar from inception until December 2023. Review Manager was used for statistical analysis. The random effects model was used to calculate risk ratios (RRs), mean differences (MDs), and 95% confidence intervals (CIs). Heterogeneity was assessed using the Higgins I2 index. The risk of bias was assessed using Cochrane's RoB 2 tool. This review has been registered with PROSPERO (CRD42023471020). Results: A total of four Chinese studies matched the inclusion criteria and were included in this review. A total of 726 patients were included in this review, out of which 476 patients were males. Out of four, three studies that studied the efficacy of 450 mg tafolecimab every 4 weeks in patients (n = 462) as compared to placebo (n = 224) were included in the meta-analysis. According to the pooled results, tafolecimab caused a significant decrease in LDL-C levels from baseline to week 12 as compared to placebo (MD = − 63.78, 95% CI − 65.88 to − 61.68, p value < 0.00001, I2 = 97%). The pooled results showed that more patients achieved ≥ 50% reductions in LDL-C levels (RR = 52.33, 95% CI 18.51–147.95, p value < 0.00001, I2 = 0%) and LDL-C < 1.8 mmol/L (RR = 17.27, 95% CI 9.59–31.11, p value < 0.00001, I2 = 0%) at week 12 in the tafolecimab group than the placebo group. Additionally, tafolecimab also caused a robust decrease in non-HDL-C, apolipoprotein B, and lipoprotein(a) levels from baseline to week 12 compared to placebo. The overall risk of bias was low, as determined by the RoB 2 tool. Conclusions: Tafolecimab showed promising lipid-lowering efficacy and a well-tolerated safety profile. Our findings suggest its potential as an innovative therapeutic option for individuals with hypercholesterolemia; however, significant heterogeneity was observed in some results, making it difficult to come to a firm conclusion. Therefore, large-scale randomized trials are required to confirm our findings, particularly exploring the most effective dosage regimens across varied populations. Registration: PROSPERO identifier number CRD42023471020. [ABSTRACT FROM AUTHOR]

Fall armyworm (Spodoptera frugiperda), a devastating pest, poses massive threat to maize (Zea mays L.) production worldwide. This study was aimed to evaluate the status of phenolics and defensive enzymes in wild (teosinte), inbred (CML 72, LM 24) and backcross derived maize line, BC (LM 24 × teosinte) exposed to fall armyworm infestation. The activities of polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), tyrosine ammonia lyase (TAL), β-1,3 glucanase, chitinase and protease inhibitor were determined. The contents of total phenols, flavonoids, ortho- dihydroxy phenols and lignin were also determined. The high stress tolerance efficiency of teosinte was attributed to the high activities of POD, PAL and TAL in its leaves during infestation that increased the content of total phenols and enhanced lignification. Additionally, it had high β-glucanase activity for the hydrolysis of glucans in the cell wall of pest. BC (LM 24 × teosinte) attained some of the unique features of teosinte as both the genotypes had comparable POD, β-glucanase, chitinase and protease inhibitor activities and equivalent levels of total phenols and lignin in their infested leaves that were relatively higher than those of LM 24. CML 72 differed significantly from LM 24 in its stress tolerance mechanism as it had maximum activities of β-glucanase, chitinase and protease inhibitor in its infested leaves. It may be concluded that teosinte followed by BC (LM 24 × teosinte) showed maximum tolerance to pest infestation. The inbred lines, LM 24 and CML 72 showed moderate tolerance to stress conditions by adopting varied mechanisms. [ABSTRACT FROM AUTHOR]

Hepatitis C virus (HCV) chronically infects approximately 170 million people worldwide and is a known etiological agent of hepatocellular carcinoma (HCC). The molecular mechanisms of HCV-mediated carcinogenesis are not fully understood. This review article focuses on the oncogenic potential of NS3, a viral protein with transformative effects on cells, although the precise mechanisms remain elusive. Unlike the more extensively studied Core and NS5A proteins, NS3's roles in cancer development are less defined but critical. Research indicates that NS3 is implicated in several carcinogenic processes such as proliferative signaling, cell death resistance, genomic instability and mutations, invasion and metastasis, tumor-related inflammation, immune evasion, and replicative immortality. Understanding the direct impact of viral proteins such as NS3 on cellular transformation is crucial for elucidating HCV's role in HCC development. Overall, this review sheds light on the molecular mechanisms used by NS3 to contribute to hepatocarcinogenesis, and highlights its significance in the context of HCV-associated HCC, underscoring the need for further investigation into its specific molecular and cellular actions. [ABSTRACT FROM AUTHOR]

Background: While the Sodium-glucose co-transporter 2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP4) are widely used for the glycemic control in type 2 diabetes mellitus, the differences in the effects of SGLT2 inhibitors and DPP4 inhibitors on energy intake and diabetes-related indicators are unclear. Methods: This was a subanalysis of the CANTABILE study which compared the effects of canagliflozin and teneligliptin on metabolic factors in Japanese patients with Type 2 diabetes. The changes at 24 weeks from the baseline of the diabetes-related indicators including Hemoglobin A1c (HbA1c), energy intake and body weight were compared between the canagliflozin and teneligliptin groups. Results: Seventy-five patients in the canagliflozin group and 70 patients in the teneligliptin group were analyzed. A significant decrease in HbA1c was observed in both groups. In the teneligliptin group, although energy intake was significantly reduced, there was no significant change in body weight. Conversely, in the canagliflozin group, although energy intake tended to increase, body weight significantly decreased. Conclusion: Canagliflozin and teneligliptin have different effects on the dietary status of patients with Type 2 diabetes. Our result suggests that canagliflozin can manage blood glucose without weight gain, even with increased energy intake. [ABSTRACT FROM AUTHOR]

Background: Metastatic melanoma stands out as the most lethal form of skin cancer because of its high propensity to spread and its remarkable resistance to treatment methods. Methods: In this review article, we address the incidence of melanoma worldwide and its staging phases. We thoroughly investigate the different melanomas and their associated risk factors. In addition, we underscore the principal therapeutic goals and pharmacological methods that are currently used in the treatment of melanoma. Results: The implementation of targeted therapies has contributed to improving the approach to patients. However, because of the emergence of resistance early in treatment, overall survival and progression-free periods continue to be limited. Conclusions: We provide new insights into plant serine protease inhibitor therapeutics, supporting high-throughput drug screening soon, and seeking a complementary approach to explain crucial mechanisms associated with melanoma. [ABSTRACT FROM AUTHOR]

Background Pre–diabetes mellitus (DM) is associated with proteinuria, a risk factor for chronic kidney disease. While people with human immunodeficiency virus (HIV; PWH) have a higher risk of proteinuria than people without HIV (PWOH), it is unknown whether incident proteinuria differs by HIV serostatus among prediabetic persons. Methods The urine protein-to-creatinine ratio was measured at semiannual visits among men in the Multicenter AIDS Cohort Study since April 2006. Men with pre-DM on or after April 2006 and no prevalent proteinuria or use of antidiabetic medications were included. Pre-DM was defined as a fasting glucose level of 100–125 mg/dL confirmed within a year by a repeated fasting glucose or hemoglobin A1c measurement of 5.7%–6.4%. Incident proteinuria was defined as a urine protein-to-creatinine ratio (UPCR) >200 mg/g, confirmed within a year. We used Poisson regression models to determine whether incident proteinuria in participants with pre-DM differed by HIV serostatus and, among PWH, whether HIV-specific factors were related to incident proteinuria. Results Between 2006 and 2019, among 1276 men with pre-DM, proteinuria developed in 128 of 613 PWH (21%) and 50 of 663 PWOH (8%) over a median 10-year follow-up. After multivariable adjustment, the incidence of proteinuria in PWH with pre-DM was 3.3 times (95% confidence interval, 2.3–4.8 times) greater than in PWOH (P <.01). Among PWH, current CD4 cell count <50/µL (P <.01) and current use of protease inhibitors (P =.03) were associated with incident proteinuria, while lamivudine and integrase inhibitor use were associated with a lower risk. Conclusions Among men with pre-DM, the risk of incident proteinuria was 3 times higher in PWH. Strategies to preserve renal function are needed in this population. [ABSTRACT FROM AUTHOR]

Introduction: The human immunodeficiency virus (HIV) remains a significant global health concern, with a reported high infection rate of 38.4 million cases globally; an estimated 2 million new infections and approximately 700,000 HIV/ AIDS-related deaths were reported in 2021. Despite the advent of anti-retroviral therapy (ART), HIV/AIDS persists as a chronic disease. To combat this, several studies focus on developing inhibitors targeting various stages of the HIV infection cycle, including HIV-1 protease. This study aims to synthesize and characterize novel glyco diphenylphosphino metal complexes with potential HIV inhibitory properties. Method: A series of new gold(I) thiolate derivatives and three bimetallic complexes, incorporating amino phosphines and thiocarbohydrate as auxiliary ligands, were synthesized using procedures described by Jiang, et al. (2009) and Coetzee et al. (2007). Structural elucidation and purity assessment of the synthesized compounds (1-11) were conducted using micro-analysis, NMR, and infrared spectrometry. Results and Discussion: Using molecular modeling techniques, three of the metal complexes were identified as potential HIV protease inhibitors, exhibiting strong binding affinity interactions with binding pocket residues. These inhibitors demonstrated an ability to inhibit the flexibility of the flap regions of the HIV protease, similar to the known HIV protease inhibitor, darunavir. This study sheds light on the promising avenues for the development of novel therapeutic agents against HIV/AIDS. [ABSTRACT FROM AUTHOR]

The protease Mpro (referred to as 3CLpro or 3CL protease) is a cysteine protease that is highly conserved in coronavirus and is indispensable for viral replication. Because there is no homologous protein for MPro in the human body, SARSCoV-2 3CL protease is an ideal target against coronavirus. Bletilla striata (Reich. Bf.) is a well-known form of Traditional Chinese Medicine and can exert many pharmacological effects, including hemostasis, anti-microbial and anti-virus activities. Our preliminary screening showed that the n-butanol component of a methanol extract of B. striata exhibited potent inhibitory activity against SARSCoV-2 3CL protease (58.82% at 200 µg/mL). In this study, we biologically evaluated ten isolated chemical compounds from B. striata and investigated the inhibitory activities of its constituents on SARS-CoV-2 3CL protease. Following bioactivity-guided fractionation, four bibenzyls (1, 4, 6 and 7), three phenols (5, 8 and 9), two anthraquinones (2 and 3) and one glucosyloxybenzyl 2-isobutylmalate (10) were isolated and evaluated for their ability to inhibit SARSCoV-2 3CL protease by fluorescence resonance energy transfer (FRET) analysis. The binding mode between compounds and enzymes was investigated by molecular docking and Saturation Transfer Differences - nuclear magnetic resonance (STD-NMR). Moreover, Pleiobibenzynin B (7), Blestritin B, Gymconopin D (4), Physcion, 3'-O-methyl dioscin III (6), Gastrodin (8) and caffeic acid (5) all exhibited inhibitory activity against 3CL protease in vitro. The four bibenzyls (1, 4, 6 and 7) exhibited good inhibitory activity against SARS-CoV-2 3CL protease (7.37-39.86 µM). These findings identify potential new inhibitors against SARS-CoV-2 3CL protease, which offers promising lead compounds for the development of novel anti-SARS-CoV-2 drugs. [ABSTRACT FROM AUTHOR]

The emergence of drug‐resistant viruses and novel strains necessitates the rapid development of novel antiviral therapies. This need was particularly demanding during the COVID‐19 pandemic. While de novo drug development is a time‐consuming process, repurposing existing approved medications offers a more expedient approach. In our prior in silico screening of the DrugBank database, fidaxomicin emerged as a potential SARS‐CoV‐2 papain‐like protease inhibitor. This study extends those findings by investigating fidaxomicin‘s antiviral properties in vitro. Our results support further exploration of fidaxomicin as a therapeutic candidate against SARS‐CoV‐2, given its promising in vitro antiviral activity and favorable safety profile. [ABSTRACT FROM AUTHOR]

Digestive midgut protease activity in fifth instar larvae (L5) of Helicoverpa armigera was investigated under controlled conditions, where, an artificial diet containing different concentrations (0.005 µg/g - 0.3 µg/g) of Cry1Ac (Crystalline ä-endotoxin from class A, subclass c) toxin was fed. Here, the Bacillus thuringiensis (Bt) cotton seeds were used as Cry1Ac toxin source that was determined using Envirologix ELISA (Enzyme Linked Immunosorbent Assay) kit. The results showed an increase in the general midgut proteases as well as specific proteases activity linked to enzymes such as trypsin-, chymotrypsin-, elastase-, and leucine aminopeptidase-like with the increasing toxin content of the diet. However, carboxypeptidase-A and carboxypeptidase-B protease activity remained unaltered as a consequence of the incorporation of Cry1Ac toxin in the diet, which is also reported to be absent in midgut of H. armigera as evident in the control group. [ABSTRACT FROM AUTHOR]

Objectives: To describe the pharmacokinetic (PK) characteristics of nirmatrelvir/ritonavir in renal transplant recipients and explore the potential factors that related to the PK variance of nirmatrelvir/ritonavir and its interaction with calcineurin inhibitor (CNI). Methods: Renal transplant recipients treated with CNI and nirmatrelvir/ritonavir were prospectively enrolled. Steady-state plasma concentrations of nirmatrelvir/ritonavir were determined by high-performance liquid chromatography-tandem mass spectrometry, and the PK parameters were calculated using non-compartmental analysis. Spearman correlation analysis was used for exploring influencing factors. Results: A total of eight recipients were enrolled; for nirmatrelvir and ritonavir, AUC/dose was 0.24179 ± 0.14495 and 0.06196 ± 0.03767 μg·h·mL-1·mg-1. Red blood cell (RBC), hematocrit (Ht), hemoglobins (Hb), and creatinine clearance (Ccr) were negatively correlated with AUC/dose of nirmatrelvir, while Ccr, CYP3A5 genotype, and CYP3A4 genotype were related to the AUC/dose of ritonavir. Ccr was negatively correlated with the C0/dose of tacrolimus (TAC) after termination of nirmatrelvir/ritonavir (rs = -0.943, p = 0.008). Conclusions: The PK characteristics of nirmatrelvir/ritonavir vary greatly among renal transplant recipients. Factors including Ccr and CYP3A5 genotype were related to the in vivo exposure of nirmatrelvir/ritonavir. During the whole process before and after nirmatrelvir/ritonavir therapy, it is recommended to adjust the CNI basing on renal function to avoid CNI toxicity exposure. [ABSTRACT FROM AUTHOR]

Linseed, also known as flax is an important oilseed crop with many potential uses in paint, textile, food and pharmaceutical industries. Susceptibility to bud fly (Dasyneura lini Barnes) infestation is a serious biotic concern leading to severe yield penalty in linseed. Protease inhibitors (PIs) are potential candidates that activate during the insect-pest attack and modulate the resistance. In the present study, we explored the PI candidates in the linseed genome and a total of 100 LuPI genes were identified and grouped into five distinct subgroups. The analysis of cis-acting elements revealed that almost all LuPI promoters contain several regulatory elementary related to growth and development, hormonal regulation and stress responses. Across the subfamilies of PIs, the specific domains are consistently found conserved in all protein sequences. The tissue-specific in-silico expression pattern via RNA-seq revealed that all the genes were regulated during different stress. The expression through qRT-PCR of 15 genes revealed the significant up-regulation of LuPI-24, LuPI-40, LuPI-49, LuPI-53, and LuPI-63 upon bud fly infestation in resistant genotype EC0099001 and resistant check variety Neela. This study establishes a foundation resource for comprehending the structural, functional, and evolutionary dimensions of protease inhibitors in linseed. [ABSTRACT FROM AUTHOR]

Tick Anticoagulant Peptide (TAP), a 60-amino acid protein from the soft tick Ornithodoros moubata, inhibits activated coagulation factor X (fXa) with almost absolute specificity. Despite TAP and Bovine Pancreatic Trypsin Inhibitor (BPTI) (i.e., the prototype of the Kunitz-type protease inhibitors) sharing a similar 3D fold and disulphide bond topology, they have remarkably different amino acid sequence (only ~24% sequence identity), thermal stability, folding pathways, protease specificity, and even mechanism of protease inhibition. Here, fully active and correctly folded TAP was produced in reasonably high yields (~20%) by solid-phase peptide chemical synthesis and thoroughly characterised with respect to its chemical identity, disulphide pairing, folding kinetics, conformational dynamics, and fXa inhibition. The versatility of the chemical synthesis was exploited to perform structure–activity relationship studies on TAP by incorporating non-coded amino acids at positions 1 and 3 of the inhibitor. Using Hydrogen–Deuterium Exchange Mass Spectrometry, we found that TAP has a remarkably higher conformational flexibility compared to BPTI, and propose that these different dynamics could impact the different folding pathway and inhibition mechanisms of TAP and BPTI. Hence, the TAP/BPTI pair represents a nice example of divergent evolution, while the relative facility of TAP synthesis could represent a good starting point to design novel synthetic analogues with improved pharmacological profiles. [ABSTRACT FROM AUTHOR]

Dabigatran etexilate (DABE) is a lipophilic double alkyl ester prodrug of dabigatran (DAB) which is a serine protease inhibitor used clinically as an anticoagulant. Recently, translocation of serine protease enzymes, including trypsin, from the gut into the mesenteric lymph and then blood has been associated with organ failure in acute and critical illnesses (ACIs). Delivery of DABE into mesenteric lymph may thus be an effective strategy to prevent organ failure in ACIs. Most drugs access the mesenteric lymph in low quantities following oral administration, as they are rapidly transported away from the intestine via the blood. Here, we examine the potential to deliver DABE into the mesenteric lymph by promoting association with lymph lipid transport pathways via co-administration with a lipid-based formulation (LBF). A series of self-emulsifying LBFs were designed and tested in vitro for their potential to form stable DABE loaded emulsions and keep DABE solubilised and stable over time in simulated gastrointestinal conditions. The LBFs were found to form fine emulsions with a droplet size of 214 ± 30 nm and DABE was stable in the formulation. The stability of DABE in vitro in simulated intestinal conditions, plasma and lymph samples was also evaluated to ensure stability in collected samples and to evaluate whether the prodrug is likely to release active DAB. Ultimately, a highly uniform and stable self-emulsifying Type III A LBF of DABE was chosen for progression into in vivo studies in male Sprague Dawley rats to confirm the lymphatic uptake and plasma pharmacokinetics. Both in vitro and in vivo in plasma and lymph, DABE was rapidly converted to an intermediate and DAB. The main species present in vivo in both plasma and lymph was DAB and mass transport of DABE and DAB in lymph was minimal (∼0.5 % of dose). Importantly, the concentration of DABE in lymph was substantially (20–176 fold) higher than in plasma, supporting that if the prodrug were stable and did not convert to DAB in the intestine, it would be lymphatically transported. Future studies will therefore focus on optimizing the design of the prodrug and formulation to improve stability during absorption and further promote lymphatic uptake. [Display omitted] • Dabigatran etexilate (DABE) was formulated into a novel stable lipid-based formulation to enhance its lymphatic uptake. • The lipid-based formulation provided protection against degradation of DABE in simulated intestinal digestion conditions. • DABE showed some lymphatic uptake following intestinal administration in the lipid-based formulation but this appeared limited by intestinal instability of DABE. [ABSTRACT FROM AUTHOR]

The present work details the synthesis of several intriguing nitrogenous heterocycles utilizing a cyano-N-aryl-acetamide-reagent, notably chlorinated thiazolidine, thiophene and 2-iminochromene derivatives. Thus, the precursor 2-cyano-N-(2,4-dichlorophenyl) acetamide 1 underwent the reaction with phenyl isothiocyanate in DMF/KOH to afford the intermediate salt 3, which reacted in situ with several α-halogenated reagents 4a-c like ethylchloroacetate,α-bromoethylpropionate and α-bromo ethyl butaneoate and afforded the corresponding 4-thiazolidinnone derivatives (6a–c, yield%; 67–85), thiophene derivatives (11;yield 80%) and (15, yield 77%) obtained from the reaction of 3 with α- chloroacetyl acetone 9 and ethyl 2-chloro-3-oxobutanoate 12.Novel series of different 4-thiazolidinones(16a–e; yield%; 65–84) were obtained via condensation of 6a with different aldehydes. Finally, the reaction of compound 1 with different bifunctional reagents, such as salicylaldehyde derivatives and 2-hydroxynaphthaldehyde, in ethanol furnished the iminochromenes (17a,b; yield %77,80) and (18; yield 85%). In addition, molecular docking studies of the prepared molecules were carried out against papain-like protease (PLpro) to identify novel promising inhibitors of Coronavirus Disease COVID-19. The binding affinity of the best docked compounds 16c and 16a toward the target enzyme was − 9.6 and − 8.9 kcal/mole, respectively. In silico-docking-Studies indicate, that compounds 16c and 16a have the potential as antiviral against COVID-19. [ABSTRACT FROM AUTHOR]

Objectives: Our aim was to determine the prevalence and characteristics of people with HIV on antiretroviral therapy (ART) with multidrug resistance (MDR; confirmed resistance to three or more [or resistance to two or more plus contraindication to one or more] core ART classes) and limited treatment options (LTOs) in Spain. Methods: This was an observational, retrospective, multicentre, cross‐sectional chart review study undertaken in five reference Spanish centres. Participants were people with HIV on ART with MDR and LTOs (detectable viral load [HIV‐RNA >200 copies/mL], treatment‐limiting drug–drug interaction [DDI], or intolerance precluding the use of one or more ART classes). Prevalence, demographic/clinical characteristics, and treatment options were assessed. Logistic regression analyses were used to identify MDR‐associated variables. Results: Of 14 955 screened people with HIV, 69 (0.46%) presented with MDR and 23 (0.15%) had LTOs. The population analysed was 73.9% male with a median age of 54.0 years; the median time since HIV diagnosis was 26.5 years, and median CD4+ cell count was 511.0 cells/μL. The only factor significantly associated with MDR (univariate analysis) was CD4+ cell count. Injection drug use was the most common transmission route. Comorbidities (mainly endocrine and cardiovascular disorders; 34.8% affecting HIV management) and concomitant treatments were frequent. No recent opportunistic infections were reported. Patients had been exposed to the following ART: nucleoside analogue reverse transcriptase inhibitors (100%), protease inhibitors (95.6%), non‐nucleoside analogue reverse transcriptase inhibitors (87.0%), and integrase strand transfer inhibitors (82.6%). The available fully active drugs were dolutegravir (39.1%), bictegravir (30.4%), and raltegravir (21.7%). Conclusions: The prevalence of people with HIV with MDR and LTOs in Spain is very low, with approximately half of those studied not exhibiting virological suppression. Low CD4+ cell counts were associated with MDR. These findings may help address the impact and treatment needs of these patients and prevent clinical progression and transmission of MDR HIV. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is an opportunistic pathogen that causes severe infections in compromised hosts. P. aeruginosa infections are difficult to treat because of the inherent ability of the bacteria to develop antibiotic resistance, secrete a variety of virulence factors, and form biofilms. The secreted aminopeptidase (PaAP) is an emerging virulence factor, key in providing essential low molecular weight nutrients and a cardinal modulator of biofilm development. PaAP is therefore a new potential target for therapy of P. aeruginosa infections. The present review summarizes the current knowledge of PaAP, with special emphasis on its biochemical and enzymatic properties, activation mechanism, biological roles, regulation, and structure. Recently developed specific inhibitors and their potential as adjuncts in the treatment of P. aeruginosa infections are also described. [ABSTRACT FROM AUTHOR]

Respiratory viral infections (VRTIs) rank among the leading causes of global morbidity and mortality, affecting millions of individuals each year across all age groups. These infections are caused by various pathogens, including rhinoviruses (RVs), adenoviruses (AdVs), and coronaviruses (CoVs), which are particularly prevalent during colder seasons. Although many VRTIs are self-limiting, their frequent recurrence and potential for severe health complications highlight the critical need for effective therapeutic strategies. Viral proteases are crucial for the maturation and replication of viruses, making them promising therapeutic targets. This review explores the pivotal role of viral proteases in the lifecycle of respiratory viruses and the development of protease inhibitors as a strategic response to these infections. Recent advances in antiviral therapy have highlighted the effectiveness of protease inhibitors in curtailing the spread and severity of viral diseases, especially during the ongoing COVID-19 pandemic. It also assesses the current efforts aimed at identifying and developing inhibitors targeting key proteases from major respiratory viruses, including human RVs, AdVs, and (severe acute respiratory syndrome coronavirus-2) SARS-CoV-2. Despite the recent identification of SARS-CoV-2, within the last five years, the scientific community has devoted considerable time and resources to investigate existing drugs and develop new inhibitors targeting the virus's main protease. However, research efforts in identifying inhibitors of the proteases of RVs and AdVs are limited. Therefore, herein, it is proposed to utilize this knowledge to develop new inhibitors for the proteases of other viruses affecting the respiratory tract or to develop dual inhibitors. Finally, by detailing the mechanisms of action and therapeutic potentials of these inhibitors, this review aims to demonstrate their significant role in transforming the management of respiratory viral diseases and to offer insights into future research directions. [ABSTRACT FROM AUTHOR]

Objective We aimed to assess the effects of neuroserpin and its combination with hypothermia on hypoxic-ischemic (HI) brain injury in neonatal rats. Neuroserpin is an axon-secreted serine protease inhibitor and is important for brain development, neuronal survival, and synaptic plasticity. Study Design Male Wistar–Albino rats on postnatal day 7 (P7) were randomly divided into five groups: sham group (n = 10), (HI; n = 10), hypoxic-ischemic hypothermia (HIH; n = 10), hypoxic-ischemic neuroserpin (HIN; n = 10), and hypoxic-ischemic neuroserpin-hypothermia (HINH; n = 10). The P7 rat brain's maturation is similar to a late preterm human brain at 34 to 36 weeks of gestation. HI was induced in rats on P7 as previously described. A single dose of 0.2 µM neuroserpin (HINH and HIN) or an equivalent volume of phosphate-buffered saline (sham, HIH, and HI) was administered intraventricularly by a Hamilton syringe immediately after hypoxia. In the follow-up, pups were subjected to systemic hypothermia or normothermia for 2 hours. Euthanasia was performed for histopathological evaluation on P10. Apoptosis was detected by caspase-3 activity and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining and was counted in the hippocampus. Results In comparison to the HI group, the TUNEL-positive and caspase-3-positive neurons in the sham, HIN, HIH, and HINH groups were considerably lower (13.4 ± 1.0 vs. 1.9 ± 0.9, 6.0 ± 0.9, 5.3 ± 1.6, and 4.0 ± 1.1; p < 0.001) and (13.5 ± 1.7 vs. 1.2 ± 0.7, 9.1 ± 2.7, 4.8 ± 1.0, and 3.9 ± 1.6; p < 0.001). HIN, HIH, and HINH, compared to the sham group, showed more TUNEL-positive and caspase-3-positive neurons (6.0 ± 0.9, 5.3 ± 1.6, 4.0 ± 1.1 vs. 1.9 ± 0.9 and 9.1 ± 2.7, 4.8 ± 1.0, 3.9 ± 1.6 vs. 1.2 ± 0.7; p < 0.001). The HINH group (synergistic effect) had significantly fewer TUNEL-positive neurons and caspase-3-positive neurons than the HIN group (4.0 ± 1.1 vs. 6.0 ± 0.9 and 3.9 ± 1.6 vs. 9.1 ± 2.7; p < 0.001). Conclusion Our study showed that both neuroserpin alone and as an adjuvant treatment for hypothermia may have a neuroprotective effect on brain injury. Key Points Neuroserpin decreased brain injury. Neuroserpin showed a synergistic effect when used as an adjuvant treatment for hypothermia. The neuroprotective effect of neuroserpine was related to its antiapoptotic properties. [ABSTRACT FROM AUTHOR]

The Trichinella spiralis novel cystatin (TsCstN) inhibits cathepsin L (CatL) activity and inflammation of macrophages during lipopolysaccharide (LPS) induction. To identify the protease inhibitory region, this study applied an in silico modeling approach to simulate truncation sites of TsCstN (Ts01), which created four truncated forms, including TsCstNΔ1–39 (Ts02), TsCstNΔ1–71 (Ts03), TsCstNΔ1–20, Δ73–117 (Ts04), and TsCstNΔ1–20, Δ42–117 (Ts05). The superimposition of these truncates modeled with AlphaFold Colab indicated that their structures were more akin to Ts01 than those modeled with I-TASSER. Moreover, Ts04 exhibited the closest resemblance to the structure of Ts01. The recombinant Ts01 (rTs01) and truncated proteins (rTs02, rTs03, and rTs04) were successfully expressed in a prokaryotic expression system while Ts05 was synthesized, with sizes of approximately 14, 12, 8, 10, and 2.5 kDa, respectively. When determining the inhibition of CatL activity, both rTs01 and rTs04 effectively reduced CatL activity in vitro. Thus, the combination of the α1 and L1 regions may be sufficient to inhibit CatL. This study provides comprehensive insights into TsCstN, particularly regarding its protein function and inhibitory domains against CatL. [ABSTRACT FROM AUTHOR]

Antinutrients, also known as anti-nutritional factors (ANFs), are compounds found in many plant-based foods that can limit the bioavailability of nutrients or can act as precursors to toxic substances. ANFs have controversial effects on human health, depending mainly on their concentration. While the positive effects of these compounds are well documented, the dangers they pose and the approaches to avoid them have not been discussed to the same extent. There is no dispute that many ANFs negatively alter the absorption of vitamins, minerals, and proteins in addition to inhibiting some enzyme activities, thus negatively affecting the bioavailability of nutrients in the human body. This review discusses the chemical properties, plant bioavailability, and deleterious effects of anti-minerals (phytates and oxalates), glycosides (cyanogenic glycosides and saponins), polyphenols (tannins), and proteinaceous ANFs (enzyme inhibitors and lectins). The focus of this study is on the possibility of controlling the amount of ANF in food through fermentation. An overview of the most common biochemical pathways for their microbial reduction is provided, showing the genetic basis of these phenomena, including the active enzymes, the optimal conditions of action, and some data on the regulation of their synthesis. [ABSTRACT FROM AUTHOR]

During the first years of COVID‐19 pandemic, X‐ray structures of the coronavirus drug targets were acquired at an unprecedented rate, giving hundreds of PDB depositions in less than a year. The main protease (Mpro) of severe acute respiratory syndrome‐related coronavirus 2 (SARS‐CoV‐2) is the primary validated target of direct‐acting antivirals. The selection of the optimal ensemble of structures of Mpro for the docking‐driven virtual screening campaign was thus non‐trivial and required a systematic and automated approach. Here we report a semi‐automated active site RMSD based procedure of ensemble selection from the SARS‐CoV‐2 Mpro crystallographic data and virtual screening of its inhibitors. The procedure was compared with other approaches to ensemble selection and validated with the help of hand‐picked and peer‐reviewed activity‐annotated libraries. Prospective virtual screening of non‐covalent Mpro inhibitors resulted in a new chemotype of thienopyrimidinone derivatives with experimentally confirmed enzyme inhibition. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether visceral adipose tissue‐derived serine protease inhibitor (vaspin) can alleviate the inhibitory effect of high‐glucose (HG) culture on the proliferation and osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) and to preliminarily explore the underlying mechanisms. Background: High glucose produces damage to the regeneration of periodontal tissue of PDLSCs. The expression level of vaspin in periodontal tissue is high in periodontitis patients and effectively reduced after initial therapy of periodontal diseases. However, the effect of vaspin on PDLSCs remains unknown. Materials and Methods: PDLSCs were cultured in media augmented with 5.5 or 25.0 mM concentrations of glucose to elucidate the impact and mechanism of vaspin on PDLSCs under high glucose in vitro. Proliferation was measured by Cell Counting Kit‐8 (CCK8) assay. Osteogenesis of PDLSCs was assessed by alkaline phosphatase (ALP) staining, ALP activity, and Alizarin Red staining. Quantitative real‐time polymerase chain reaction (qRT‐PCR) and western blot (WB) were used to investigate the osteo‐specific markers. Then, the molecular impact of vaspin in the presence/absence of HG on PDLSCs physiology was determined with TGF‐β1/Smad signaling pathway as the main focus. Results: It was revealed that the proliferation and osteogenic differentiation (OD) of PDLSCs under HG was reduced, and by adding vaspin the anti‐osteogenic impact of HG was relieved. Moreover, vaspin enhanced TGF‐β1/Smad signaling pathway activity. Pretreatment with TGF‐β1 inhibitor blocked vaspin‐triggered TGF‐β1/Smad signal activation and minimized the vaspin‐induced protective effect against HG‐inhibited growth and OD. Conclusions: In summary, vaspin observably reduces HG‐mediated inhibition of PDLSCs OD by modulating the TGF‐β1/Smad signaling pathway. Vaspin may be a potential therapeutic for periodontal tissue regeneration in diabetic patients. [ABSTRACT FROM AUTHOR]

Serine protease inhibitors (serpins) participate in the regulation of inflammation, blood coagulation, and complement activation in humans. This research aimed to identify and characterize such inhibitors of the human liver fluke Opisthorchis viverrini. Parasite proteins that might contribute to the modulation of host physiology are of particular interest, especially as chronic opisthorchiasis increases the risk of developing biliary cancer. BLAST was used to find hypothetical serpins predicted from the parasite genome data. RNA extraction and reverse transcriptase PCR were used to isolate a serpin cDNA and to determine developmental transcript abundance. The evolutionary relation to other trematode serpins was revealed by phylogenetic analysis. Recombinant serpin was expressed in Escherichia coli and used to test the immunoreactivity of human opisthorchiasis sera and the inhibition of human serine proteases. A substantial serpin family with high sequence divergence among the members was found in the genus Opisthorchis. A serpin, different from previously analyzed trematode serpins, was cloned. The transcript was only detected in metacercariae and newly excysted juveniles. Human opisthorchiasis sera showed statistically significant reactivity to recombinant serpin. The serpin caused moderate inhibition of thrombin and low inhibition of kallikrein and chymotrypsin. This parasite serpin could be further evaluated as a diagnostic tool for early infection. Kallikrein and thrombin are involved in fibrinolysis; therefore, further research should explore the effects of the parasite serpin on this process. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic-led worldwide healthcare crisis necessitates prompt societal, ecological, and medical efforts to stop or reduce the rising number of fatalities. Numerous mRNA based vaccines and vaccines for viral vectors have been licensed for use in emergencies which showed 90% to 95% efficacy in preventing SARS-CoV-2 infection. However, safety issues, vaccine reluctance, and skepticism remain major concerns for making mass vaccination a successful approach to treat COVID-19. Hence, alternative therapeutics is needed for eradicating the global burden of COVID-19 from developed and low-resource countries. Repurposing current medications and drug candidates could be a more viable option for treating SARS-CoV-2 as these therapies have previously passed a number of significant checkpoints for drug development and patient care. Besides vaccines, this review focused on the potential usage of alternative therapeutic agents including antiviral, antiparasitic, and antibacterial drugs, protease inhibitors, neuraminidase inhibitors, and monoclonal antibodies that are currently undergoing preclinical and clinical investigations to assess their effectiveness and safety in the treatment of COVID-19. Among the repurposed drugs, remdesivir is considered as the most promising agent, while favipiravir, molnupiravir, paxlovid, and lopinavir/ritonavir exhibited improved therapeutic effects in terms of elimination of viruses. However, the outcomes of treatment with oseltamivir, umifenovir, disulfiram, teicoplanin, and ivermectin were not significant. It is noteworthy that combining multiple drugs as therapy showcases impressive effectiveness in managing individuals with COVID-19. Tocilizumab is presently employed for the treatment of patients who exhibit COVID-19-related pneumonia. Numerous antiviral drugs such as galidesivir, griffithsin, and thapsigargin are under clinical trials which could be promising for treating COVID-19 individuals with severe symptoms. Supportive treatment for patients of COVID-19 may involve the use of corticosteroids, convalescent plasma, stem cells, pooled antibodies, vitamins, and natural substances. This study provides an updated progress in SARS-CoV-2 medications and a crucial guide for inventing novel interventions against COVID-19. [ABSTRACT FROM AUTHOR]

Serine proteases (SPs) are distributed among all living cells accounting for almost one-third of all proteases. Dysregulation of SPs during inflammation and/or infection can result in devastating consequences, such as skin and lung inflammation, neuroinflammation, arthritis, as well as metastasis of cancerous cells. Such activities are tightly regulated by various inhibitors known as serine protease inhibitors (SERPIN). The thermodynamic investigations previously revealed that L-ascorbic acid binds to trypsin more firmly than pepsin and the binding force of L-ascorbic acid is driven by hydrogen bonds and van der Waals forces. However, the physiochemical effects of such interaction on trypsin and/or pepsin have not yet been reported. Ascorbic acid, also known as vitamin C, is one of the essential nutrients and most common food supplements, fortificants, and preservatives. The aim of this study was to explore the inhibitory effects of ascorbic acid on serine proteases at various concentrations on the in-vitro digestion and/or hydrolysis of intercellular matrix of cell monolayer and human serum albumin (HSA). The inhibitory effects of ascorbic on trypsin are investigated by qualitative and quantitative analysis using SDS-PAGE imaging and NIH densitometric software. Upon the addition of ascorbic acid in both indicator systems, the detachment and/or dissociation of cell monolayer and the digestion of HSA were inhibited in the presence of EDTA-Trypsin. The inhibitory effect of ascorbic acid on the digestion of intercellular matrix and/or hydrolysis of HSA showed a dose-dependent trend until it reached the maximum extent of inhibition. At an equal concentration (2.5mg/mL) ascorbic acid and EDTA-Trypsin exhibited the most potent inhibitory effect on the in vitro digestion of protein either in the form of intercellular matrix in cell monolayer and/or HSA respectively. Overall, our results based on two indicator systems strongly indicate that ascorbic acid may function as a serine protease inhibitor (SERPIN) beyond other important functions. [ABSTRACT FROM AUTHOR]

Objective: Routine viral load and drug resistance testing are well supported in most resource-rich settings and provide valuable benefits in the clinical care of PLWH in these communities. Undoubtedly, there exist financial and political constraints for the scale-up of viral load and drug resistance testing in Sub-Saharan Africa. To achieve the global UNAIDS 95/95/95 targets, there is the need to bridge this inequity in patient care and allow for a universal approach that leaves no community behind. Methods: Venous blood from 96 PLWH on second-line ART from Korle-Bu Teaching Hospital were collected and processed into plasma for CD4+ T- cell and viral load assessments. Ribonucleic acid (RNA) was extracted from stored plasma and the protease gene amplified, sequenced and analyzed for subtype and drug resistance mutations using the Stanford HIV drug resistance database. Results: Out of the 96 PLWH, 37 experienced virological failure with 8 patients' samples successfully sequenced. The predominant HIV-1 subtype identified was CRF02_AG (6/8, 75.0%) with 12.5% (1/8) each of CFR06_cpx infection and one case unable to subtype. The major PI resistance mutations identified were; M46I, I54V, V82A, I47V, I84V and L90M. Conclusions: Persons living with HIV who had experienced virologic failure in this study harboured drug resistance mutations to PI, thus compromise the effectiveness of the drugs in the second line. Resistance testing is strongly recommended prior to switching to a new regimen. This will help to inform the choice of drug and to achieve optimum therapeutic outcome among PLWH in Ghana. Highlights: Protease inhibitors (PI) are prescribed for patients failing on reverse transcriptase-based regimen without adequate monitoring for viral load and drug resistance testing. The study provides evidence of PI resistance mutations and their implications for the relatively fewer individuals on PI-based regimen in the era of dolutegravir (DTG) use. Close monitoring on all HIV infected patients on PI is needed. [ABSTRACT FROM AUTHOR]

Background: Camostat mesylate, an oral serine protease inhibitor, is a powerful TMPRSS2 inhibitor and has been reported as a possible antiviral treatment against COVID-19. Therefore, we aim to assess the safety and efficacy of camostat mesylate for COVID-19 treatment. Methods: A systematic review and meta-analysis synthesizing randomized controlled trials from PubMed, Scopus, Embase, Cochrane, Web of Science, clinical trials.gov, and medrxiv until June 2023. The outcomes were pooled using Mean difference (MD) for continuous outcomes and risk ratio (RR) for dichotomous outcomes. The protocol is registered in PROSPERO with ID CRD42023439633. Results: Nine RCTs, including 1,623 patients, were included in this analysis. There was no difference between camostat mesylate and placebo in producing negative PCR test results at 1–7 days (RR: 0.76, 95% CI: [0.54, 1.06] P = 0.1), 8–14 days (RR: 1.02, 95% CI: [0.84, 1.23] P = 0.87), or 15–21 days (RR: 0.99, 95% CI: [0.82, 1.19] P = 0.90); clinical resolution of symptoms at 1–7 days (RR: 0.94 (95% CI: 0.58, 1.53) P = 0.81), 8–14 days (RR: 0.91, 95% CI: [0.74, 1.11] P = 0.33,), or 15–21 days (RR: 0.77, 95% CI: [0.40, 1.51] P = 0.45); and time to symptom improvement (MD:-0.38 weeks (95% CI: [-1.42, 0.66] P = 0.47, I2 = 85%). Conclusion: Camostat mesylate did not improve clinical outcomes in patients with COVID-19, compared to placebo. [ABSTRACT FROM AUTHOR]

Simple Summary: This review highlights SerpinB3's multifaceted roles in liver disease, from fibrosis, carcinogenesis and immune modulation to cell death protection. In different types of cancer its overexpression correlates with tumor aggressiveness; however, in acute oxidative stress conditions, SerpinB3 promotes cell survival. Novel therapeutic strategies targeting SerpinB3 through its upstream regulators are under development, while its therapeutic potential in acute medical conditions has also been proposed. SerpinB3, a member of the serine-protease inhibitor family, has emerged as a crucial player in various physiological and pathological processes. Initially identified as an oncogenic factor in squamous cell carcinomas, SerpinB3's intricate involvement extends from fibrosis progression and cancer to cell protection in acute oxidative stress conditions. This review explores the multifaceted roles of SerpinB3, focusing on its implications in fibrosis, metabolic syndrome, carcinogenesis and immune system impairment. Furthermore, its involvement in tissue protection from oxidative stress and wound healing underscores its potential as diagnostic and therapeutic tool. Recent studies have described the therapeutic potential of targeting SerpinB3 through its upstream regulators, offering novel strategies for cancer treatment development. Overall, this review underscores the importance of further research to fully elucidate the mechanisms of action of SerpinB3 and to exploit its therapeutic potential across various medical conditions. [ABSTRACT FROM AUTHOR]

Background Long-acting (LA) injectable therapy with cabotegravir (CAB) and rilpivirine (RPV) is currently used as maintenance treatment for human immunodeficiency virus type 1, and has a low risk for virological failure (VF). Although the risk is low, the circumstances and impact of VF in the real-world setting merit further evaluation. Methods We performed an in-depth clinical, virological, and pharmacokinetic analysis on the reasons behind and the impact of VF during LA CAB/RPV therapy in 5 cases from the Netherlands. Genotypic resistance testing was performed after the occurrence of VF, and drug plasma (trough) concentrations were measured after VF was established and on any other samples to assess on-treatment drug levels. CAB and RPV drug levels that were below the first quartile of the population cutoff (≤Q1) were considered to be low. Results Five cases who were eligible for LA CAB/RPV experienced VF despite a low predicted risk at baseline. Genotypic resistance testing revealed extensive selection of nonnucleoside reverse transcriptase inhibitor–associated mutations in all cases, and integrase strand transfer inhibitor mutations in 4 cases. All cases displayed low drug levels of either CAB, RPV, or both during the treatment course, likely contributing to the occurrence of VF. In 3 cases, we were able to identify the potential mechanisms behind these low drug levels. Conclusions This is the first in-depth multiple case analysis of VF on LA CAB/RPV therapy in a real-world setting. Our observations stress the need to be aware for (evolving) risk factors and the yield of a comprehensive clinical, virological, and pharmacokinetic approach in case of failure. [ABSTRACT FROM AUTHOR]

Mucus injury associated with goblet cell (GC) depletion constitutes an early event in inflammatory bowel disease (IBD). Using single-cell sequencing to detect critical events in mucus dysfunction, we discover that the Kazal-type serine protease inhibitor SPINK4 is dynamically regulated in colitic intestine in parallel with disease activities. Under chemically induced colitic conditions, the grim status in Spink4-conditional knockout mice is successfully rescued by recombinant murine SPINK4. Notably, its therapeutic potential is synergistic with existing TNF-α inhibitor infliximab in colitis treatment. Mechanistically, SPINK4 promotes GC differentiation using a Kazal-like motif to modulate EGFR-Wnt/β-catenin and -Hippo pathways. Microbiota-derived diacylated lipoprotein Pam2CSK4 triggers SPINK4 production. We also show that monitoring SPINK4 in circulation is a reliable noninvasive technique to distinguish IBD patients from healthy controls and assess disease activity. Thus, SPINK4 serves as a serologic biomarker of IBD and has therapeutic potential for colitis via intrinsic EGFR activation in intestinal homeostasis. The early stages of inflammatory bowel disease involve mucus injury and depletion of goblet cells. Here, the authors show that SPINK4 could serve as a serological biomarker of IBD and holds therapeutic potential for goblet cell regeneration via intrinsic EGFR activation under colitic conditions [ABSTRACT FROM AUTHOR]

Serine protease inhibitors (serpins) include thousands of structurally conserved proteins playing key roles in many organisms. Mutations affecting serpins may disturb their conformation, leading to inactive forms. Unfortunately, conformational consequences of serpin mutations are difficult to predict. In this study, we integrate experimental data of patients with mutations affecting one serpin with the predictions obtained by AlphaFold and molecular dynamics. Five SERPINC1 mutations causing antithrombin deficiency, the strongest congenital thrombophilia were selected from a cohort of 350 unrelated patients based on functional, biochemical, and crystallographic evidence supporting a folding defect. AlphaFold gave an accurate prediction for the wild-type structure. However, it also produced native structures for all variants, regardless of complexity or conformational consequences in vivo. Similarly, molecular dynamics of up to 1000 ns at temperatures causing conformational transitions did not show significant changes in the native structure of wild-type and variants. In conclusion, AlphaFold and molecular dynamics force predictions into the native conformation at conditions with experimental evidence supporting a conformational change to other structures. It is necessary to improve predictive strategies for serpins that consider the conformational sensitivity of these molecules. [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) continues to be a global threat due to its ability to evolve and generate new subvariants, leading to new waves of infection. Additionally, other coronaviruses like Middle East respiratory syndrome coronavirus (MERS-CoV, formerly known as hCoV-EMC), which first emerged in 2012, persist and continue to present a threat of severe illness to humans. The continued identification of novel coronaviruses, coupled with the potential for genetic recombination between different strains, raises the possibility of new coronavirus clades of global concern emerging. As a result, there is a pressing need for pan-CoV therapeutic drugs and vaccines. After the extensive optimization of an HCV protease inhibitor screening hit, a novel 3CLPro inhibitor (MK-7845) was discovered and subsequently profiled. MK-7845 exhibited nanomolar in vitro potency with broad spectrum activity against a panel of clinical SARS-CoV-2 subvariants and MERS-CoV. Furthermore, when administered orally, MK-7845 demonstrated a notable reduction in viral burdens by >6 log orders in the lungs of transgenic mice infected with SARS-CoV-2 (K18-hACE2 mice) and MERS-CoV (K18-hDDP4 mice). [ABSTRACT FROM AUTHOR]

Taspase 1 is a unique protease not only pivotal for embryonic development but also implicated in leukemias and solid tumors. As such, this enzyme is a promising while still challenging therapeutic target, and with its protein structure featuring a flexible loop preceding the active site a versatile model system for drug development. Supramolecular ligands provide a promising complementary approach to traditional small‐molecule inhibitors. Recently, the multivalent arrangement of molecular tweezers allowed the successful targeting of Taspase 1’s surface loop. With this study we now want to take the next logic step und utilize functional linker systems that not only allow the implementation of novel properties but also engage in protein surface binding. Consequently, we chose two different linker types differing from the original divalent assembly: a backbone with aggregation‐induced emission (AIE) properties to enable monitoring of binding and a calix[4]arene scaffold initially pre‐positioning the supramolecular binding units. With a series of four AIE‐equipped ligands with stepwise increased valency we demonstrated that the functionalized AIE linkers approach ligand binding affinities in the nanomolar range and allow efficient proteolytic inhibition of Taspase 1. Moreover, implementation of the calix[4]arene backbone further enhanced the ligands’ inhibitory potential, pointing to a specific linker contribution. [ABSTRACT FROM AUTHOR]

Transitioning from pediatric to adult care remains a challenge for adolescents and young adults with perinatally-acquired HIV (AYA-PHIV). We assessed treatment outcomes and mortality among Thai AYA-PHIV. The study included AYA-PHIV who reached age 18–24 years who started antiretroviral treatment during childhood at five pediatric HIV clinics across Thailand. From November 2020–July 2021, data were gathered from a cohort database, medical records, and the Thai National AIDS Program. Of 811 eligible AYA-PHIV, 93% were alive; median age 22.3 years (IQR 20.6–23.7), treatment duration 16.1 years (IQR 13.4–18.0). Current HIV care was provided in adults (71%) and pediatric clinics (29%). Treatment regimens included non-nucleoside reverse transcriptase inhibitors (55%), protease inhibitors (36%), and integrase inhibitors (8%); 78% had HIV RNA <200 copies/ml. Of the 7.0% who died, median age at death was 20.8 years (IQR 20.6–22.1); 88% were AIDS-related death. Mortality after age 18 was 1.76 per 100-person years (95% confidence interval 1.36–2.28). Those with CD4 <200 cell/mm3 at age 15 had higher risk of mortality (adjusted hazard ratio 6.16, 95% CI 2.37–16.02). In conclusion, the high mortality among Thai AYA-PHIV indicated the need for better systems to support AYA-PHIV during the transition to adulthood. [ABSTRACT FROM AUTHOR]

Aprotinin is a broad-spectrum inhibitor of human proteases that has been approved for the treatment of bleeding in single coronary artery bypass surgery because of its potent antifibrinolytic actions. Following the outbreak of the COVID-19 pandemic, there was an urgent need to find new antiviral drugs. Aprotinin is a good candidate for therapeutic repositioning as a broad-spectrum antiviral drug and for treating the symptomatic processes that characterise viral respiratory diseases, including COVID-19. This is due to its strong pharmacological ability to inhibit a plethora of host proteases used by respiratory viruses in their infective mechanisms. The proteases allow the cleavage and conformational change of proteins that make up their viral capsid, and thus enable them to anchor themselves by recognition of their target in the epithelial cell. In addition, the activation of these proteases initiates the inflammatory process that triggers the infection. The attraction of the drug is not only its pharmacodynamic characteristics but also the possibility of administration by the inhalation route, avoiding unwanted systemic effects. This, together with the low cost of treatment (≈2 Euro/dose), makes it a good candidate to reach countries with lower economic means. In this article, we will discuss the pharmacodynamic, pharmacokinetic, and toxicological characteristics of aprotinin administered by the inhalation route; analyse the main advances in our knowledge of this medication; and the future directions that should be taken in research in order to reposition this medication in therapeutics. [ABSTRACT FROM AUTHOR]

Since the outbreak of the COVID-19 pandemic caused by the SARS-CoV-2 virus, there has been a pressing need for effective and accessible antiviral agents. Aminocaproic acid (Epsilon-aminocaproic acid, EACA), known primarily for its antifibrinolytic properties, has recently been in the spotlight for its potential cytotoxic and antiviral capabilities. This study aims to evaluate the in vitro cytotoxicity and antiviral activity of EACA against SARS-CoV-2.An in-depth in vitro analysis was conducted in isolated laboratories to determine the cytotoxic effects of EACA on cell cultures and its potential to inhibit SARS-CoV-2 replication. Assays to assess the direct in-vitro antiviral activity of EACA against the virus were performed (Vero E6 cell culture), considering viral entry inhibition and protein interaction disruption. The cytotoxic concentration (TTC50) for EACA on Vero E6 cell culture was set at 35,128 µg/ml (p = 0.05). EACA at concentrations of 1093 µg/ml, 2187 µg/ml, 4375 µg/ml, 8750 µg/ml, 17500 µg/ml, 25000 µg/ml, and 35000 µg/ml does not have therapeutic or virus inhibitory activity against the SARS-CoV-2 virus at a dose of 100 TCD50/0.2 ml. The use of EACA for the treatment or prevention of SARS-CoV-2 may not be effective. This highlights the need to continue searching for other effective candidates from the protease inhibitors group. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: The legume crop cowpea is grown worldwide, but 90% of the world's total share is produced in Africa. It is a promising species due to its resilience properties, balance of macro and micronutrients and presence of health‐promoting bioactive compounds. In African countries, cowpea has a crucial role in guaranteeing food security as a subsistence crop for families and commercial income for small farmers. The discovery of compounds with high nutraceutical value and bioactive properties supports socio‐economic policies to improve health and nutrition, especially in low‐ and middle‐income countries. In turn, this encourages biodiversity protection and crop enhancement programmes. Summary: Bowman–Birk protease inhibitors (BBIs) are a restricted group of small proteins in plants mainly involved in defence mechanisms against pests. BBIs are demonstrated to be active components capable of reducing the viabilities of different cancer cell lines. BBI bioactivity is directly linked to the inhibition capacity, but the variability and the efficiency against the physiological targets of different BBI isoforms remain still unexplored.We analysed the natural genetic diversity of two main genes encoding BBI trypsin‐trypsin (BBI‐TT) and trypsin‐chymotrypsin (BBI‐TC) in wild and domesticated cowpea samples mainly spread in Sub‐Saharan Africa. We analysed DNA sequences and respective amino acidic isoforms/isoproteins to explore signs of natural selection and haplotype relationships. Moreover, we calculated the binding energy between BBIs and their biological targets to identify which are the most efficient inhibitors and their geographical locations.We found a high level of haplotype diversity for both genes, almost exclusively in wild accessions and detected positive and negative selection signals in the amino acid sequences. Furthermore, in the wild diversity pool, some BBI‐TT and BBI‐TC mature proteins were potentially better interactors with the physiological targets.The long interaction between plant‐pathogen has selected new and useful isoforms in wild lineages that have allowed the chances of survival of the species to improve. On the other hand, the domestication process has produced an intense bottleneck leaving only poorly efficient BBI variants. In addition to providing information on the natural diversity and evolution of BBIs, our work discusses the potential applications in agriculture and human health. [ABSTRACT FROM AUTHOR]

The sea cucumber is an essential nutrient source and a significant economic marine resource associated with successful aquaculture. However, sea cucumbers are highly susceptible to autolysis induced by endogenous protease after postmortem, and the phenomenon of body wall “melting” occurs, which seriously affects the food quality of products and the degree of acceptance by consumers. To satisfy the growing demand for fresh or processed sea cucumbers, we must clarify the autolysis mechanism of sea cucumbers and the methods to achieve autolysis regulation. In this paper, the factors leading to the quality deterioration and texture softening of sea cucumbers are reviewed, with emphasis on enzymatic characteristics, the autolysis mechanism, the effects of autolysis on the physicochemical properties of the body wall of the sea cucumber, and the development of potential natural protease inhibitors. We aim to provide some reference in future preservation and processing processes for sea cucumbers, promote new processing and preservation technologies, and advance the sea cucumber industry’s development. [ABSTRACT FROM AUTHOR]

The prevalence of hyperlipidemia has increased significantly due to genetic, dietary, nutritional and pharmacological factors, and has become one of the most common pathological conditions in humans. Hyperlipidemia can lead to a range of diseases such as atherosclerosis, stroke, coronary heart disease, myocardial infarction, diabetes, and kidney failure, etc. High circulating low-density lipoprotein cholesterol (LDL-C) is one of the causes of hyperlipidemia. LDL-C in the blood binds to LDL receptor (LDLR) and regulates cholesterol homeostasis through endocytosis. In contrast, proprotein convertase subtilisin/kexin type 9 (PCSK9) mediates LDLR degradation via the intracellular and extracellular pathways, leading to hyperlipidemia. Targeting PCSK9-synthesizing transcription factors and downstream molecules are important for development of new lipid-lowering drugs. Clinical trials regarding PCSK9 inhibitors have demonstrated a reduction in atherosclerotic cardiovascular disease events. The purpose of this review was to explore the target and mechanism of intracellular and extracellular pathways in degradation of LDLR and related drugs by PCSK9 in order to open up a new pathway for the development of new lipid-lowering drugs. [ABSTRACT FROM AUTHOR]

Abstract Linseed, also known as flax is an important oilseed crop with many potential uses in paint, textile, food and pharmaceutical industries. Susceptibility to bud fly (Dasyneura lini Barnes) infestation is a serious biotic concern leading to severe yield penalty in linseed. Protease inhibitors (PIs) are potential candidates that activate during the insect-pest attack and modulate the resistance. In the present study, we explored the PI candidates in the linseed genome and a total of 100 LuPI genes were identified and grouped into five distinct subgroups. The analysis of cis-acting elements revealed that almost all LuPI promoters contain several regulatory elementary related to growth and development, hormonal regulation and stress responses. Across the subfamilies of PIs, the specific domains are consistently found conserved in all protein sequences. The tissue-specific in-silico expression pattern via RNA-seq revealed that all the genes were regulated during different stress. The expression through qRT-PCR of 15 genes revealed the significant up-regulation of LuPI-24, LuPI-40, LuPI-49, LuPI-53, and LuPI-63 upon bud fly infestation in resistant genotype EC0099001 and resistant check variety Neela. This study establishes a foundation resource for comprehending the structural, functional, and evolutionary dimensions of protease inhibitors in linseed.

Abstract Objective Routine viral load and drug resistance testing are well supported in most resource-rich settings and provide valuable benefits in the clinical care of PLWH in these communities. Undoubtedly, there exist financial and political constraints for the scale-up of viral load and drug resistance testing in Sub-Saharan Africa. To achieve the global UNAIDS 95/95/95 targets, there is the need to bridge this inequity in patient care and allow for a universal approach that leaves no community behind. Methods Venous blood from 96 PLWH on second-line ART from Korle-Bu Teaching Hospital were collected and processed into plasma for CD4+ T- cell and viral load assessments. Ribonucleic acid (RNA) was extracted from stored plasma and the protease gene amplified, sequenced and analyzed for subtype and drug resistance mutations using the Stanford HIV drug resistance database. Results Out of the 96 PLWH, 37 experienced virological failure with 8 patients’ samples successfully sequenced. The predominant HIV-1 subtype identified was CRF02_AG (6/8, 75.0%) with 12.5% (1/8) each of CFR06_cpx infection and one case unable to subtype. The major PI resistance mutations identified were; M46I, I54V, V82A, I47V, I84V and L90M. Conclusions Persons living with HIV who had experienced virologic failure in this study harboured drug resistance mutations to PI, thus compromise the effectiveness of the drugs in the second line. Resistance testing is strongly recommended prior to switching to a new regimen. This will help to inform the choice of drug and to achieve optimum therapeutic outcome among PLWH in Ghana.

Antiviral therapeutics to treat SARS-CoV-2 are needed to diminish the morbidity of the ongoing COVID-19 pandemic. A well-precedented drug target is the main viral protease (MPro ), which is targeted by an approved drug and by several investigational drugs. Emerging viral resistance has made new inhibitor chemotypes more pressing. Adopting a structure-based approach, we docked 1.2 billion non-covalent lead-like molecules and a new library of 6.5 million electrophiles against the enzyme structure. From these, 29 non-covalent and 11 covalent inhibitors were identified in 37 series, the most potent having an IC50 of 29 and 20 μM, respectively. Several series were optimized, resulting in low micromolar inhibitors. Subsequent crystallography confirmed the docking predicted binding modes and may template further optimization. While the new chemotypes may aid further optimization of MPro inhibitors for SARS-CoV-2, the modest success rate also reveals weaknesses in our approach for challenging targets like MPro versus other targets where it has been more successful, and versus other structure-based techniques against MPro itself.