Peptidase Inhibitors Research Articles

Triazole scaffold-based DPP-IV Inhibitors for the management of Type-II Diabetes Mellitus: Insight into Molecular Docking and SAR.

Diabetes mellitus, characterized as a chronic metabolic disorder or a polygenic syndrome; is increasing at a very fast pace among every group of the population worldwide. It arises due to the inability of the body to produce enough insulin (the hormone responsible for controlling blood sugar levels) or inability to utilize the insulin, leading to hyperglycaemic condition, which, if left uncontrolled gives rise to chronic microvascular and macrovascular complications like retinopathy, neuropathy, nephropathy, coronary artery disease, cognitive impairment, etc. Several therapeutic approaches are available for the treatment of diabetes; among which dipeptidyl peptidase (DPP-IV) inhibitors (gliptins) hold a significant place. DPP-IV is a multifunctional enzyme or a serine exopeptidase that plays an imperative role in cleaving bioactive molecules. DPP-IV causes the breakdown of incretin hormone (GLP-1: Glucagon-like peptide 1 and GIP: Glucose-dependent insulinotropic peptide) that is essential for controlling glycaemic levels in the body. Inhibition of DPP-IV enzyme (DPP-IV inhibitors: Sitagliptin, Saxagliptin, Linagliptin, Alogliptin) prevents this breakdown, thereby controlling blood glucose levels and saving the patients from deleterious effects of prolonged hyperglycaemic conditions. Triazole-based DPP-IV inhibitors are a significant class of drugs used to treat Type 2 diabetes mellitus in a dose-dependent manner. Clinical trials have demonstrated their efficacy as monotherapy or in combination with other antidiabetic agents. This review highlights the molecular docking studies and structure-activity relationship of potential synthetic derivatives that may act as lead molecules for future drug discovery and yield drug molecules with enhanced efficacy, potency and reduced toxicity profile.

Wuzi-Yanzong-Wan Prevents the Defect of Cell-Cell Junctions between Sertoli-Germ Cells by Up-Regulating the Expression of TAp73.

The TAp73 gene is an anti-cancer gene that also affects the junction between Sertoli and germ cells. Inhibition of this gene causes infertility in male mice. Our previous research proved that Wuzi-Yanzong-Wan (WZYZW) can protect spermatogenesis and maturation by preventing TAp73 inhibition. This study aimed to investigate the effect of drug-containing serum of WZYZW on the defect of cell-cell junctions in the Sertoli-germ cells co-culture system in vitro. LC-HRMS was used to analyze the content of active ingredients in WZYZWmedicated serum. Then, primary extraction and co-culture of germ cells and Sertoli cells were carried out. Co-cultured cells were added with PFT-α to induce the TAp73 inhibition model, with WZYZW-medicated serum at 2.5%, 5%, and 10% treated in parallel. Sloughing of germ cells from Sertoli cells was calculated. Transmission electron microscopy (TEM), Immunofluorescence, qRT-PCR, and western blot methods were employed. The drug-containing serum of WZYZW contained schisandrin, hyperoside, geniposidic acid, ellagic acid, and quercetin. Using TEM assay, we observed restoration of the desmosomelike (Des), tight junctions (TJ), and basal ectoplasmic specialization (ES) structure following WZYZW treatment. WZYZW caused inhibition of peptidase and protease inhibitors (tissue inhibitor of metalloproteinase-1 (TIMP1), Serpina3n) by immunofluorescence analysis. Western blot and qRT-PCR analysis revealed that WZYZW was able to ameliorate the expressions of peptidase and protease inhibitors and cell adhesion factors, such as TAp73, TIMP1, Serpina3n, Desmocollin-3, N-cadherin, and Nectin-2. WZYZW-medicated serum could prevent the defect of cell-cell junctions between Sertoli-germ cells co-culture system in vitro by up-regulating the expression of TAp73.

Truncated NPY-based NPY(Y1)R-specific radiopeptides: Improved in vivo PET tumor imaging by application of peptidase inhibitors

The neuropeptide Y receptor subtype 1 (NPY(Y1)R) exhibits high expression rates on human breast cancer and is therefore an important target structure for the sensitive and specific visualization and characterization of the disease by Positron Emission Tomography (PET). However, imaging of this receptor type has been of limited success so far due to the low stability of peptide-based NPY-derived NPY(Y1)R-specific radiotracer candidates due to in vivo degradation. Given the challenges in stabilizing these agents, our study sought to explore whether the stability of NPY(Y1)R-specific radiopeptides could be enhanced. We aimed to achieve this by either modifying the peptide structure with various molecular scaffolds or by applying peptidase inhibitors. This evaluation aimed to identify the optimal approach for achieving effective NPY(Y1)R-specific imaging in the following. To validate our approach, we systematically investigated four new truncated 68Ga-labeled analogs of NPY and the reference compound [68Ga]Ga-[Lys4(Nε-DOTA)]BVD15, bearing different molecular scaffolds such as a DOTA or NODA-GA chelator, a 4-APipAc linker, a Bip unit, and an N-terminal Lys(lauryl) group. The four new radiotracers as well as the reference compound were obtained in high chemical and radiochemical yields with molar activities of 33–39 GBq/μmol. The radiopeptides exhibited varying logD7.4 values, ranging from −3.37 ± 0.09 to +0.35 ± 0.11, and showed different levels of stability in human serum and liver microsomes, depending on their molecular structure. Subsequently, the influence of the peptidase inhibitors actinonin, phosphoramidon, captopril and E−64 on the in vitro stability of the radiotracers was investigated. In these studies, only actinonin demonstrated a positive effect on the stability of all radiopeptides. In contrast, phosphoramidon yielded variable results, and neither captopril nor E−64 showed a significant stabilizing effect.Consequently, the effect of actinonin administration on the in vivo PET/CT imaging results of the most promising ligand [68Ga]Ga-[Lys4(Nε-NODA-GA)]BVD15 ([68Ga]Ga-2) was investigated in a T47D tumor-bearing xenograft mouse model, followed by ex vivo biodistribution studies. In these experiments, the administration of 250 μg actinonin resulted in a significantly increased uptake of [68Ga]Ga-2 in the T47D tumor (5.9 ± 1.0 % ID/g (with actinonin) instead of 3.1 ± 0.9 % ID/g (without actinonin) at 2h p.i.), and an increase in tumor-to-muscle ratios from 1.8 to 4.0 upon co-administration of the inhibitor.The results impressively demonstrate the positive influence of actinonin on the in vivo stability of the NPY(Y1)R-specific radiopeptide [68Ga]Ga-2, resulting in an increased tumor accumulation and improved tumor-to-background ratios. These findings thus provide important incentive for further advancement of NPY(Y1)R-specific tumor imaging using PET.

Optimization of ultrasound-assisted extraction method of Syzygium cumini leaves based on extraction yield, content of bioactive compound, and inhibition of dipeptidyl peptidase IV enzyme activity using response surface methodology

Syzygium cumini leaves show potential to be developed as herbal medicine products against diabetes mellitus due to their high polyphenol contents. S. cumini was optimized using response surface methodology and Box–Behnken design with solvent solid ratio, solvent concentration, time and temperature, extraction yield, total flavonoid content (TFC), total phenolic content (TPC), and dipeptidyl peptidase IV (DPP-IV) enzyme inhibitory activity to obtain an effective and optimal extraction method. The conditions were achieved using a 70% ethanol solvent for the extraction, with a solvent–solid ratio of 21 v/w and run at 20°C for 30 min. The results showed an extraction yield of 83.875%, with TFCs measuring at 3.068 mg QE/g, TPCs of 65.029 mg GAE/g, and DPP-IV enzyme inhibition activity of 66.079%. Further analysis of the phytochemical profile using untargeted liquid chromatography-high-resolution mass spectrometry showed the presence of amine, amide, and fatty acid derivatives as major constituents. In addition, major flavonoids observed were myricetin and myricitrin, accounting for 0.2%. Ursolic acid and 25-azacholesterol accounted for 1.03% of the phenolics detected.

Vaccinia virus F1Lblocks the ribotoxic stress response to subvert ZAKα-dependent NLRP1 inflammasome activation.

Inflammasomes are essential for host defense, recognizing foreign or stress signals to trigger immune responses, including maturation of IL-1 family cytokines and pyroptosis. Here, NLRP1 is emerging as an important sensor of viral infection in barrier tissues. NLRP1 is activated by various stimuli, including viral double-stranded (ds) RNA, ribotoxic stress, and inhibition of dipeptidyl peptidases 8 and 9 (DPP8/9). However, certain viruses, most notably the vaccinia virus, have evolved strategies to subvert inflammasome activation or effector functions. Using the modified vaccinia virus Ankara (MVA) as a model, we investigated how the vaccinia virus inhibits inflammasome activation. We confirmed that the early gene F1L plays a critical role in inhibiting NLRP1 inflammasome activation. Interestingly, it blocks dsRNA and ribotoxic stress-dependent NLRP1 activation without affecting its DPP9-inhibition-mediated activation. Complementation and loss-of-function experiments demonstrated the sufficiency and necessity of F1L in blocking NLRP1 activation. Furthermore, we found that F1L-deficient, but not wild-type MVA, induced ZAKα activation. Indeed, an F1L-deficient virus was found to disrupt protein translation more prominently than an unmodified virus, suggesting that F1L acts in part upstream of ZAKα. These findings underscore the inhibitory role of F1L on NLRP1 inflammasome activation and provide insight into viral evasion of host defenses and the intricate mechanisms of inflammasome activation.

Bioactive Peptides from Corn (Zea mays L.) with the Potential to Decrease the Risk of Developing Non-Communicable Chronic Diseases: In Silico Evaluation.

Studies have shown that corn (Zea mays L.) proteins, mainly α-zein, have the potential to act on therapeutic targets related to non-communicable chronic diseases, such as high blood pressure and type 2 diabetes. Enzymatic hydrolysis of proteins present in foods can result in a great diversity of peptides with different structures and possible bioactivities. A review of recent scientific research papers was performed to show evidence of the bioactive properties of corn peptides by in vitro assays. The α-zein amino acid sequences were identified in the UniProtKB protein database and then analyzed in the BIOPEP database to simulate enzymatic digestion and verify the potential biological action of the resulting peptides. The peptides found in the BIOPEP database were categorized according to the probability of presenting biological action using the PeptideRanker database. The aim was to use existing data to identify in silico the potential for obtaining biologically active peptides from α-zein, the main storage protein of corn. The analysis showed that the majority of peptide fragments were related to the inhibition of angiotensin-converting enzyme, followed by the inhibition of dipeptidyl peptidase IV and dipeptidyl peptidase III. Many drugs used to treat high blood pressure and type 2 diabetes work by inhibiting these enzymes, suggesting that corn peptides could be potential alternative agents. In vitro studies found that the primary bioactivity observed was antioxidative action. Both in vitro and in silico approaches are valuable for evaluating the bioactive properties resulting from protein hydrolysis, such as those found in α-zein. However, conducting in vitro studies based on prior in silico evaluation can be more efficient and cost-effective.

Design, Synthesis, molecular dynamic analysis, and In-Vivo anti-diabetic evaluation of novel hydrazine carboximidamide derivatives

Diabetes is one of the most rapidly growing health problems globally, and researchers working hard to develop novel efficient therapies against it. In this regard, hydrazine carboximidamide has a great deal of attention owing to its diverse biological activities. Herein, a new series of N, N-disubstituted hydrazine carboximidamide derivatives was designed, synthesized, and assessed for their antidiabetic activity. Docking studies were performed to initially evaluate the binding of the designed compounds to the target enzyme. It was found that all of the pivotal ligand-enzyme interactions, including the interactions with Glu205/Glu206 aminoacids were observed in docking studies. The molecular dynamic analysis showed that the antidiabetic activity of the newly developed compounds may be implemented through the inhibition of dipeptidyl peptidase 4 (DPP-4), an important target that involves enhancing insulin release and suppressing glucagon discharge from the pancreas. The target molecules were synthesized practically and all the newly-developed chemical structures were confirmed via spectrophotometric methods, including IR, LC-MS, 1H NMR, and 13C NMR techniques. Finally, the in-vivo studies were carried out to confirm the results obtained from the docking and molecular dynamics studies. Compounds 6b and 6d demonstrated improved glucose tolerance through oral glucose tolerance tests in NMRI mice (at a dose of 10 mg/kg). Furthermore, prolonged administration of compounds 6b and 6d to diabetic Wistar rats for 14 days led to a noteworthy reduction in blood levels of glucose, akin to the effects observed with sitagliptin, a standard diabetes medication.

Talabostat, fibroblast activation protein inhibitor, attenuates inflammation and fibrosis in systemic sclerosis.

Systemic sclerosis (SSc) is a connective tissue disorder characterized by excessive fibrosis, where activated fibroblasts play a pivotal role in disease progression. This study aimed to investigate the potential of Talabostat, a small molecule inhibitor of dipeptidyl peptidases, in alleviating fibrosis and inflammation associated with SSc pathogenesis. Dermal fibroblasts were obtained from skin biopsies of ten diffuse cutaneous SSc patients and healthy controls. These fibroblasts were subjected to treatment with either TGF-β alone or in combination with Talabostat. Immunofluorescence staining was conducted to evaluate FAPα and α-SMA protein levels. The expression of activated fibroblast markers (FAPα and ACAT2), pro-fibrotic (COL1A1 and COL1A2), anti-fibrotic (MMP1, MMP2, and MMP9), and inflammatory (IL-6 and TGFβ1) related genes was measured by quantitative real-time PCR. Talabostat-treated fibroblasts were assessed for their migratory capacity using a scratch assay and for their viability through MTT assay and Annexin V staining. The basal expression of COL1A1 and TGFβ1 was notably higher in healthy subjects, while MMP1 expression showed a significant increase in SSc patients. Furthermore, TGF-β stimulation led to upregulation of activated fibroblast markers, pro-fibrotic, and inflammatory-related genes in SSc-derived fibroblasts, which were attenuated upon Talabostat treatment. Interestingly, Talabostat treatment resulted in an upregulation of MMP9 expression. Moreover, Talabostat exhibited a concentration-dependent inhibition of activated fibroblast viability in both healthy and SSc fibroblasts, and suppressed fibroblast migration specifically in SSc patients. In summary, Talabostat modulates fibrotic genes in SSc, thereby inhibiting myofibroblast differentiation, activation, and migration. These findings suggest promising therapeutic avenues for targeting fibrosis in SSc.

A Novel Kunitz Trypsin Inhibitor from Enterolobium gummiferum Seeds Exhibits Antibiofilm Properties against Pathogenic Yeasts.

Plant peptidase inhibitors play crucial roles in plant defence mechanisms and physiological processes. In this study, we isolated and characterised a Kunitz trypsin inhibitor from Enterolobium gummiferum seeds named EgPI (E. gummiferum peptidase inhibitor). The purification process involved two chromatography steps using size exclusion and hydrophobic resins, resulting in high purity and yield. EgPI appeared as a single band of ~20 kDa in SDS-PAGE. Under reducing conditions, the inhibitor exhibited two polypeptide chains, with 15 and 5 kDa. Functional characterisation revealed that EgPI displayed an inhibition stoichiometry of 1:1 against trypsin, with a dissociation constant of 8.4 × 10-9 mol·L-1. The amino-terminal sequencing of EgPI revealed the homology with Kunitz inhibitors. Circular dichroism analysis provided insights into the secondary structure of EgPI, which displayed the signature typical of Kunitz inhibitors. Stability studies demonstrated that EgPI maintained the secondary structure necessary to exhibit its inhibitory activity up to 70 °C and over a pH range from 2 to 8. Microbiological screening revealed that EgPI has antibiofilm properties against pathogenic yeasts at 1.125 μmol·L-1, and EgPI reduced C. albicans biofilm formation by 82.7%. The high affinity of EgPI for trypsin suggests potential applications in various fields. Furthermore, its antibiofilm properties recommended its usefulness in agriculture and antimicrobial therapy research, highlighting the practical implications of our research.

Angiotensin Receptors and Neprilysin Inhibitors on Myocardial Remodeling in Patients with Acute Myocardial Infarction after Percutaneous Coronary Intervention

Heart failure (HF) is a leading cause of late morbidity and mortality after acute myocardial infarction worldwide. Myocardial remodeling is an important mechanism in the development of chronic heart failure. Development of the HF phenotype in these patients arise from a complex, progressive, molecular and cellular transformation called “ventricular remodeling”. In this paper, the research progress of myocardial remodeling is summarized. Left ventricular remodeling is characterized by a progressive increase in both end-diastolic (LVEDV) and end-systolic volumes (LVESV). Cardium remodeling is due to an increased activity of cardiac fibroblasts in response to different soluble fibrogenic mediators. ARNI can inhibit the biological activity of brain natriuretic peptide enzyme, prevent the deactivation of natriuretic peptide and increase its concentration. The inhibition of brain natriuretic peptidase and the increase of natriuretic peptide level by ARNI is an important means to treat heart failure and fight against ventricular remodeling, and the inhibition of RAAS system over activation is also of great significance to delay myocardial remodeling. much of the observed clinical benefit of sacubitril/valsartan therapy in patients with HFrEF, HFpEF and in the post-myocardial infarction setting is likely related to significant reverse cardiac remodeling.

Pharmacologic inhibition of dipeptidyl peptidase 1 (cathepsin C) does not block in vitro granzyme-mediated target cell killing by CD8 T or NK cells.

Recently developed small-molecule inhibitors of the lysosomal protease dipeptidyl peptidase 1 (DPP1), also known as cathepsin C (CatC), can suppress suppurative inflammation in vivo by blocking the processing of zymogenic (pro-) forms of neutrophil serine proteases (NSPs), including neutrophil elastase, proteinase 3, and cathepsin G. DPP1 also plays an important role in activating granzyme serine proteases that are expressed by cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. Therefore, it is critical to determine whether DPP1 inhibition can also cause off-target suppression of CTL/NK-cell-mediated killing of virus-infected or malignant cells. Herein, we demonstrate that the processing of human granzymes A and B, transitioning from zymogen to active proteases, is not solely dependent on DPP1. Thus, the killing of target cells by primary human CD8+ T cells, NK cells, and gene-engineered anti-CD19 CAR T cells was not blocked in vitro even after prior exposure to high concentrations of the reversible DPP1 inhibitor brensocatib. Consistent with this observation, the turnover of model granzyme A/B peptide substrates in the human CTL/NK cell lysates was not significantly reduced by brensocatib. In contrast, preincubation with brensocatib almost entirely abolished (>90%) both the cytotoxic activity of mouse CD8+ T cells and granzyme substrate turnover. Overall, our finding that the effects of DPP1 inhibition on human cytotoxic lymphocytes are attenuated in comparison to those of mice indicates that granzyme processing/activation pathways differ between mice and humans. Moreover, the in vitro data suggest that human subjects treated with reversible DPP1 inhibitors, such as brensocatib, are unlikely to experience any appreciable deficits in CTL/NK-cell-mediated immunities.

Epigallocatechin gallate alleviates non-alcoholic fatty liver disease through the inhibition of the expression and activity of Dipeptide kinase 4

BackgroundNon-alcoholic fatty liver disease (NAFLD) has emerged as the most prevalent glocal cause of chronic hepatic disease, with incidence rates that continue to rise steadily. Treatment options for affected patients are currently limited to dietary changes and exercise interventions, with no drugs having been licensed for the treatment of this disease. There is thus a pressing need for the development of novel therapeutic strategies. Work from our group suggests that the primary bioactive ingredient in green tea, epigallocatechin gallate (EGCG), may help reduce liver fat content and protect against hepatic injury through the inhibition of dipeptidyl peptidase 4 (DPP4) expression and activity. The study investigated the potential pathways by which EGCG may improve NAFLD, identified the sites of interaction between EGCG and DPP4, and proposed novel clinical treatment strategies. MethodsA clinical randomized controlled trial was conducted to investigate the potential efficacy of EGCG in NAFLD patients. The study compared relevant indices before and after EGCG administration. Animal models of NAFLD were constructed using male C57BL/6J mice fed a high-fat diet to observe the ameliorative effects of EGCG on the livers of the model mice and to investigate the potential pathways by which EGCG alleviates NAFLD. The interaction mechanism between EGCG and DPP4 was investigated using oleic acid and palmitic acid-treated HepG2 cell lines. Plasmids in which different sites had been disrupted were used to identify the effective interaction sites. ResultsECGC was found to suppress the accumulation of lipids, inhibit inflammation, remediate dysregulated lipid metabolism, and improve the pathogenesis of NAFLD via the inhibition of the expression and activity of DPP4. ConclusionsThe study results indicate that EGCG has a positive impact on improving NAFLD. These results highlight promising new opportunities to safely and effectively treat NAFLD in the clinic. Study id numberChiCTR2300076741; https://www.chictr.org.cn/

The genome-wide response of Dermatophagoides pteronyssinus to cystatin A, a peptidase inhibitor from human skin, sheds light on its digestive physiology and allergenicity.

The digestive physiology of house dust mites (HDMs) is particularly relevant for their allergenicity since many of their allergens participate in digestion and are excreted into faecal pellets, a main source of exposure for allergic subjects. To gain insight into the mite dietary digestion, the genome of the HDM Dermatophagoides pteronyssinus was screened for genes encoding peptidases (n = 320), glycosylases (n = 77), lipases and esterases (n = 320), peptidase inhibitors (n = 65) and allergen-related proteins (n = 52). Basal gene expression and transcriptional responses of mites to dietary cystatin A, a cysteine endopeptidase inhibitor with previously shown antinutritional effect on mites, were analysed by RNAseq. The ingestion of cystatin A resulted in significant regulation of different cysteine endopeptidase and glycosylase genes. One Der p 1-like and two cathepsin B-like cysteine endopeptidase genes of high basal expression were induced, which suggests their prominent role in proteolytic digestion together with major allergen Der p 1. A number of genes putatively participating in the interaction of mites with their microbiota and acquired by horizontal gene transfer were repressed, including genes encoding the peptidase Der p 38, two 1,3-beta-glucanases, a lysozyme and a GH19 chitinase. Finally, the disruption of mite digestion resulted in the regulation of up to 17 allergen and isoallergen genes. Altogether, our results shed light on the putative role of specific genes in digestion and illustrate the connection between the digestive physiology of HDM and allergy.

The monodomain Kunitz protein EgKU-7 from the dog tapeworm Echinococcus granulosus is a high-affinity trypsin inhibitor with two interaction sites.

Typical Kunitz proteins (I2 family of the MEROPS database, Kunitz-A family) are metazoan competitive inhibitors of serine peptidases that form tight complexes of 1:1 stoichiometry, mimicking substrates. The cestode Echinococcus granulosus, the dog tapeworm causing cystic echinococcosis in humans and livestock, encodes an expanded family of monodomain Kunitz proteins, some of which are secreted to the dog host interface. The Kunitz protein EgKU-7 contains, in addition to the Kunitz domain with the anti-peptidase loop comprising a critical arginine, a C-terminal extension of ∼20 amino acids. Kinetic, electrophoretic, and mass spectrometry studies using EgKU-7, a C-terminally truncated variant, and a mutant in which the critical arginine was substituted by alanine, show that EgKU-7 is a tight inhibitor of bovine and canine trypsins with the unusual property of possessing two instead of one site of interaction with the peptidases. One site resides in the anti-peptidase loop and is partially hydrolyzed by bovine but not canine trypsins, suggesting specificity for the target enzymes. The other site is located in the C-terminal extension. This extension can be hydrolyzed in a particular arginine by cationic bovine and canine trypsins but not by anionic canine trypsin. This is the first time to our knowledge that a monodomain Kunitz-A protein is reported to have two interaction sites with its target. Considering that putative orthologs of EgKU-7 are present in other cestodes, our finding unveils a novel piece in the repertoire of peptidase-inhibitor interactions and adds new notes to the evolutionary host-parasite concerto.

Dipeptidyl Peptidase-4 (DPP-4) Inhibitors: New Oral Medications for the Treatment of Type 2 Diabetes

Type 2 diabetes (T2D) is a metabolic disorder characterized by hyperglycaemia, insulin resistance at peripheral target tissues, and pancreatic β-cell dysfunction. It is a global health problem with epidemic proportions and a huge economic burden. The dipeptidyl peptidase (DPP-4) inhibitors are a new class of antihyperglycaemic agents that are developed for the treatment of T2D. Many clinical studies have suggested that DPP-4 inhibitors (gliptins) are safe from cardiovascular perspective, and may also possess cardioprotective effect. These are regulators of inflammation and metabolism, and also prevent the proteolytic breakdown. These reduce postprandial glucose with minimal risk of hypoglycaemia and gastrointestinal adverse effects. These increase biologically intact forms of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), both of which enhance glucose-induced insulin secretion from pancreatic β-cells. These medications become popular and are widely used worldwide for their efficacy, safety, weight neutrality, and tolerability. This article reviews basic studies of the DPP-4 inhibitors in briefly for the management of T2D.

Higher Expression of Lympho-epithelial Kazal-type-Related Inhibitor-1 Fragments and Decreased Desquamation in the Lesional Skin of Nummular Eczema.

Nummular eczema, a chronic dermatitis characterized by coin-shaped lesions, was first documented in 1857. However, its pathophysiological characteristics are still not well known. To investigate differences in the regulation of the desquamation process in the stratum corneum of lesional and nonlesional skin of patients with nummular eczema and healthy control subjects, tape-stripped stratum corneum samples from patients with nummular eczema and healthy volunteers were analysed using immunofluorescence staining and western blot analysis. In the nummular eczema lesional skin, expression of desmoglein-1, desmocollin-1, and corneodesmosin exhibited a disorganized, dense or partially diffuse non-peripheral pattern with increased intensity, compared with the peripheral patterns observed in healthy or nonlesional skin, suggesting the impaired desquamation process in nummular eczema. Furthermore, although the expression of the desquamation-related serine proteases, kallikrein-related peptidase 7 and 5, was increased in nummular eczema lesional skin, the immunofluorescence staining of lympho-epithelial Kazal-type-related inhibitor-1, an endogenous inhibitor of various kallikrein-related peptidases, and its fragments were significantly increased in the nummular eczema lesional skin, suggesting its contribution to the inhibition of corneodesmosomal degradation. Therefore, the increased detection of corneodesmosomal proteins in nummular eczema lesions may be due to the increased amount of the fragments of lympho-epithelial Kazal-type-related inhibitor-1, which could contribute to delayed desquamation.

The ecotin-like peptidase inhibitor of Trypanosoma cruzi prevents TMPRSS2-PAR2-TLR4 crosstalk downmodulating infection and inflammation.

Trypanosoma cruzi is the causative agent of Chagas disease, a chronic pathology that affects the heart and/or digestive system. This parasite invades and multiplies in virtually all nucleated cells, using a variety of host cell receptors for infection. T. cruzi has a gene that encodes an ecotin-like inhibitor of serine peptidases, ISP2. We generated ISP2-null mutants (Δisp2) in T. cruzi Dm28c using CRISPR/Cas9. Epimastigotes of Δisp2 grew normally invitro but were more susceptible to lysis by human serum compared to parental and ISP2 add-back lines. Tissue culture trypomastigotes of Δisp2 were more infective to human muscle cells invitro, which was reverted by the serine peptidase inhibitors aprotinin and camostat, suggesting that host cell epitheliasin/TMPRSS2 is the target of ISP2. Pretreatment of host cells with an antagonist to the protease-activated receptor 2 (PAR2) or an inhibitor of Toll-like receptor 4 (TLR4) selectively counteracted the increased cell invasion by Δisp2, but did not affect invasion by parental and add-back lines. The same was observed following targeted gene silencing of PAR2, TLR4 or TMPRSS2 in host cells by siRNA. Furthermore, Δisp2 caused increased tissue edema in a BALB/c mouse footpad infection model after 3 h differently to that observed following infection with parental and add-back lines. We propose that ISP2 contributes to protect T. cruzi from the anti-microbial effects of human serum and to prevent triggering of PAR2 and TLR4 in host cells, resulting in the modulation of host cell invasion and contributing to decrease inflammation during acute infection.

Enhancing the nutritional and bioactive benefits of faba bean flour by combining preprocessing and thermoplastic extrusion: A comprehensive study on digestion-resistant peptides

This research assessed how three preprocessing techniques [soaking (S), soaking and reconstitution (SR), and soaking and dehulling (SD)] impact the protein digestibility and bioactivity of faba bean flours when combined with thermoplastic extrusion. Samples were compared against a control (C) of extruded faba bean flour without preprocessing. Applying preprocessing techniques followed by extrusion diminished antinutrient levels while enhancing protein hydrolysis and in vitro bioactivity in higher extent compared to C. Specifically, SD combined with extrusion was the most effective, achieving an 80% rate of protein hydrolysis and uniquely promoting the release of gastric digestion-resistant proteins (50-70 kDa). It also resulted in the highest release of small peptides (<3kDa, 22.51%) and free amino acids (15.50%) during intestinal digestion. Moreover, while all preprocessing techniques increased antioxidant (ABTS radical-scavenging), antidiabetic, and anti-hypertensive activities, SD extruded flour displayed the highest levels of dipeptidyl peptidase inhibition (DPP-IVi, IC50=13.20 µg/mL), pancreatic α-amylase inhibition (IC50=8.59 mg/mL), and angiotensin I-converting enzyme inhibition (ACEi, IC50=1.71 mg protein/mL). As a result, it was selected for further peptide and in silico bioactive analysis. A total of 24 bioactive peptides were identified in intestinal digests from SD extruded flour, all with potential DPP-IVi and ACEi activities, and six were also predicted as antioxidant peptides. VIPAGYPVAIK and GLTETWNPNHPEL were highlighted as resistant bioactive peptides with the highest antidiabetic and antioxidant potential. Our findings demonstrated that combining preprocessing (particularly SD) and thermoplastic extrusion enhances protein digestibility in faba beans and promotes the release of beneficial bioactive peptides in the intestine.

Diverse Pharmacological Potential of Pyridazine Analogs against Various Diseases.

Pyridazinone analogs possess diverse types of pharmacological activities, such as anticancer, antimicrobial, anticonvulsant, analgesic, anti-inflammatory, antioxidant, antihypertensive, antisecretory, antiulcer, and other useful pharmacological activities. They also possess cyclooxygenase (COX) inhibitors, dipeptidyl peptidase inhibitors, phosphodiesterase inhibitors, glutamate transporter activators, adenosine receptor antagonists, serotonin receptors antagonists, lipooxygenase, cholinesterase, vasodilator, and anesthetics. Pyridazine rings are the essential structure for some marketed drugs, such as pimobendan, levosimendan as a cardiotonic drug, and emorfozan as an analgesic and anti-inflammatory (Non-steroidal anti-inflammatory drug) agent. So, researchers all over the world have paid attention to synthesizing various pyridazinone compounds mainly due to the ease of design and synthesis of different analogs and variables in the pharmacological responses. This review article focuses on the pharmacological activities of different pyridazine analogs.

Network-based screening identifies sitagliptin as an antitumor drug targeting dendritic cells

BackgroundDendritic cell (DC)-mediated antigen presentation is essential for the priming and activation of tumor-specific T cells. However, few drugs that specifically manipulate DC functions are available. The identification of drugs...