Target Proteins Research Articles

From Tyrosine Kinases to Tyrosine Phosphatases: New Therapeutic Targets in Cancers and Beyond

Protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) regulate the level of tyrosine phosphorylation in proteins. PTKs are key enzymes that catalyze the transfer of an ATP phosphoric acid to a tyrosine residue on target protein substrates. Protein tyrosine phosphatases (PTPs) are responsible for the dephosphorylation of tyrosine residues and play a role in countering PTK overactivity. As widespread oncogenes, PTKs were once considered to be promising targets for therapy. However, tyrosine kinase inhibitors (TKIs) now face a number of challenges, including drug resistance and toxic side effects. Treatment strategies now need to be developed from a new perspective. In this review, we assess the current state of TKIs and highlight the role of PTPs in cancer and other diseases. With the advances of allosteric inhibition and the development of multiple alternative proprietary drug strategies, the reputation of PTPs as “undruggable” targets has been overturned, and they are now considered viable therapeutic targets. We also discuss the strategies and prospects of PTP-targeted therapy, as well as its future development.

Diacylglycerol kinase is a keystone regulator of signaling relevant to the pathophysiology of asthma.

Signal transduction by G protein-coupled receptors (GPCRs), receptor tyrosine kinases (RTKs) and immunoreceptors converge at the activation of phospholipase C (PLC) for the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). This is a point for second-messenger bifurcation where DAG via protein kinase C (PKC) and IP3 via calcium activate distinct protein targets and regulate cellular functions. IP3 signaling is regulated by multiple calcium influx and efflux proteins involved in calcium homeostasis. A family of lipid kinases belonging to DAG kinases (DGKs) converts DAG to phosphatidic acid (PA), negatively regulating DAG signaling and pathophysiological functions. PA, through a series of biochemical reactions, is recycled to produce new molecules of PIP2. Therefore, DGKs act as a central switch in terminating DAG signaling and resynthesis of membrane phospholipids precursor. Interestingly, calcium and PKC regulate the activation of α and ζ isoforms of DGK that are predominantly expressed in airway and immune cells. Thus, DGK forms a feedback and feedforward control point and plays a crucial role in fine-tuning phospholipid stoichiometry, signaling, and functions. In this review, we discuss the previously underappreciated complex and intriguing DAG/DGK-driven mechanisms in regulating cellular functions associated with asthma, such as contraction and proliferation of airway smooth muscle (ASM) cells and inflammatory activation of immune cells. We highlight the benefits of manipulating DGK activity in mitigating salient features of asthma pathophysiology and shed light on DGK as a molecule of interest for heterogeneous diseases such as asthma.

Integrative network pharmacology, molecular docking, and dynamic simulation analysis of a polyherbal formulation for potential therapeutic impact on prostate cancer

BackgroundProstate cancer (PCa) remains a significant health concern globally, prompting a continual search for novel therapeutic strategies. In this study, we employed a comprehensive approach combining network pharmacology, molecular docking and dynamic simulation to explore the potential impact of a polyherbal formulation on PCa. MethodsUtilizing comprehensive network pharmacology approaches, we elucidated the complex interactions between the bioactive compounds within the polyherbal formulation and key targets associated with PCa progression, highlighting their multitarget mechanisms through integrated protein‒protein interaction and KEGG pathway analyses. Molecular docking simulation studies were performed to predict the binding affinities and modes of interaction between the identified bioactive compounds and their respective protein targets. ResultsComplex connections comprising 486 nodes and 845 edges were found by the compound-target network analysis. Significant interactions were observed, and the average node degree was 4.23. KEGG research revealed that PCa and the PI3K-Akt signalling pathway are implicated in modulating prostate cancer. The Quercetin docking investigations revealed that the binding energies for AR and PIK3R1 were −9 and −9.5 kcal/mol, respectively. Based on the results of the MD simulations, it appears that tiny molecules and proteins have formed stable complexes with low fluctuations. ConclusionIn conclusion, this comprehensive method emphasises the value of network pharmacology in conjunction with molecular docking and dynamic simulation in revealing the anti-PCa therapeutic potential of polyherbal formulations, opening up new possibilities for the creation of efficient anti-cancer medicines.

CaAOS as a hub gene based on physiological and transcriptomic analyses of cold-resistant and cold-sensitive pepper cultivars

The yield and quality of pepper are considerably influenced by the cold conditions. Herein, we performed morphological, physiological and transcriptomic analyses by using two pepper seedlings, ‘2379’ (cold-resistant) and ‘2380’ (cold-sensitive). Briefly, 60 samples from each cultivar were analyzed at four distinct time points (0, 6, 24 and 48 h) at 5 °C in darkness. The physiological indices and activities of enzymes exhibited marked differences between the two cultivars. Transcriptomic analysis indicated that, compared to the control group, 11,415 DEGs were identified in ‘2379’ and ‘2380’ at 24 h. In the early stage, the number of DEGs in ‘2379’ was 5.68 times higher than that in ‘2380’, potentially explaining the observed differences in tolerance to colds. Processes such as protein targeting to membranes, jasmonic acid (JA)–mediated signalling, cold response and abscisic acid–activated signalling were involved. Subsequently, we identified a hub gene, CaAOS, that is involved in JA biosynthesis, positively influences cold tolerance and is a target of CaMYC2. Variations in the GC-motif of the CaAOS's promoter may influence the expression levels of CaAOS under cold treatment. The result of this study may lead to the development of more effective strategies for enhancing cold tolerance, potentially benefitting pepper breeding in cold regions.

Targeting the Coronavirus SARS‑CoV‑2’s Envelope, Nucleocapsid, and Spike/ Spike RBD Protein: Computational Insight from Multiple Bioactive Compounds as Potential Anti-Viral Drug Candidates

Global health, social, and economic systems have been seriously threatened by the coronavirus disease (COVID-19) pandemic. In addition to the increasing number of deaths, thousands of COVID-19 survivors continue to experience life-altering illness. This study aimed to evaluate multiple bioactive compounds from various indigenous medicinal plants against the structural proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including the envelope, nucleocapsid, and spike/spike receptor-binding domain (RBD) proteins, in search of potential antiviral drug candidates. Computational analysis was used to screen for binding affinities and assess chemical interactions between ligands and target proteins. The findings revealed the top three potential compounds to bind to the envelope protein (cafestol, kahweol, and ledene), nucleocapsid protein (cafestol, kahweol, and thearubigin), spike protein (tannic acid, eugeniin, and kahweol), and spike RBD protein (kahweol, cafestol, and tannic acid). Moreover, the study identified four types of plants that contain potential bioactive compounds against SARS-CoV-2 structural proteins, including black tea (Camellia sinensis), clove (Syzygium aromaticum), common bean (Phaseolus vulgaris), and star anise (Illicium verum). Interestingly, kahweol exhibited possible binding activity against all four target proteins. This result suggests that bioactive compounds from the listed medicinal plants could potentially be developed into antiviral drugs against COVID-19.

Targeting the Coronavirus SARS‑CoV‑2’s Envelope, Nucleocapsid, and Spike/ Spike RBD Protein: Computational Insight from Multiple Bioactive Compounds as Potential Anti-Viral Drug Candidates

Global health, social, and economic systems have been seriously threatened by the coronavirus disease (COVID-19) pandemic. In addition to the increasing number of deaths, thousands of COVID-19 survivors continue to experience life-altering illness. This study aimed to evaluate multiple bioactive compounds from various indigenous medicinal plants against the structural proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including the envelope, nucleocapsid, and spike/spike receptor-binding domain (RBD) proteins, in search of potential antiviral drug candidates. Computational analysis was used to screen for binding affinities and assess chemical interactions between ligands and target proteins. The findings revealed the top three potential compounds to bind to the envelope protein (cafestol, kahweol, and ledene), nucleocapsid protein (cafestol, kahweol, and thearubigin), spike protein (tannic acid, eugeniin, and kahweol), and spike RBD protein (kahweol, cafestol, and tannic acid). Moreover, the study identified four types of plants that contain potential bioactive compounds against SARS-CoV-2 structural proteins, including black tea (Camellia sinensis), clove (Syzygium aromaticum), common bean (Phaseolus vulgaris), and star anise (Illicium verum). Interestingly, kahweol exhibited possible binding activity against all four target proteins. This result suggests that bioactive compounds from the listed medicinal plants could potentially be developed into antiviral drugs against COVID-19.

Quercetin attenuated ropivacaine-induced neurotoxicity in SH-SY5Y cells through upregulating Pim1 and enhancing autophagy

BackgroundRopivacaine (Rop) is a local anesthetic that is widely used but is also potentially harmful. Quercetin (Quer) is a flavonoid component found in many plants and traditional Chinese medicines. It possesses anti-oxidant, anti-inflammatory, antitumor, and neuroprotective properties as a pharmaceutical. In Rop-induced neurotoxicity, the functions and molecular basis of Quer remain unclear. MethodsCell viability and proliferation were assessed using CCK-8 and 5-ethynyl-2′-deoxyuridine (EdU) incorporation assays, respectively. Apoptosis and autophagy were defined by both morphological criteria and markers such as caspase3 cleavage and monodansylcadaverine (MDC) staining. Western blot and immunofluorescence staining were evaluated. The target proteins were then predicted using molecular docking and validated at the cellular and protein levels. ResultsQuer was shown to significantly reduce Rop-induced viability inhibition and apoptosis in SH-SY5Y cells in a dose-dependent manner. Moreover, Quer reduced Rop-induced cytotoxicity by stimulating autophagy in SH-SY5Y cells by targeting the Pim1 protein, which was accomplished via the AMPK/mTOR pathway. ConclusionQuer relieved Rop-induced neurotoxicity in SH-SY5Y cells through upregulating Pim1 and enhancing autophagy, indicating that Quer may have potential therapeutic applications in the treatment of Rop-induced neurotoxicities.

Research Progress in the Regulation of the ABA Signaling Pathway by E3 Ubiquitin Ligases in Plants.

E3 ubiquitin ligases (UBLs), as enzymes capable of specifically recognizing target proteins in the process of protein ubiquitination, play crucial roles in regulating responses to abiotic stresses such as drought, salt, and temperature. Abscisic acid (ABA), a plant endogenous hormone, is essential to regulating plant growth, development, disease resistance, and defense against abiotic stresses, and acts through a complex ABA signaling pathway. Hormone signaling transduction relies on protein regulation, and E3 ubiquitin ligases play important parts in regulating the ABA pathway. Therefore, this paper reviews the ubiquitin-proteasome-mediated protein degradation pathway, ABA-related signaling pathways, and the regulation of ABA-signaling-pathway-related genes by E3 ubiquitin ligases, aiming to provide references for further exploration of the relevant research on how plant E3 ubiquitin ligases regulate the ABA pathway.

Tailoring Fibroblast-Activation Protein Targeting for Theranostics: A Comparative Preclinical Evaluation of the 68Ga- and 177Lu-Labeled Monomeric and Dimeric Fibroblast-Activation Protein Inhibitors DOTA.SA.FAPi and DOTAGA.(SA.FAPi)2.

FAP radiopharmaceuticals show promise for cancer diagnosis; however, their limited tumor residency hinders treatment. This study compared two FAPi derivatives, DOTA.SA.FAPi and DOTAGA.(SA.FAPi)2, labeled with gallium-68 and lutetium-177, aiming to determine an optimum combination for creating theranostic pairs. The radiotracers were studied for lipophilicity, binding to human serum proteins, and binding to human cancer-associated fibroblasts (CAFs) in vitro, including saturation and internalization/externalization studies. PET/SPECT/CT and biodistribution studies were conducted in PC3 and U87MG xenografts for [68Ga]Ga-DOTA.SA.FAPi and [68Ga]Ga-DOTAGA.(SA.FAPi)2. [177Lu]Lu-DOTA.SA.FAPi and [177Lu]Lu-DOTAGA.(SA.FAPi)2, were evaluated in PC3 xenografts. Biodistribution studies of [68Ga]Ga-DOTA.SA.FAPi were performed in healthy male and female mice. All radiotracers exhibited strong binding to FAP. Their internalization rate was fast while only [177Lu]Lu-DOTAGA.(SA.FAPi)2 was retained longer in CAFs. [68Ga]Ga-DOTAGA.(SA.FAPi)2 and [177Lu]Lu-DOTAGA.(SA.FAPi)2 displayed elevated lipophilicity and affinity for human serum proteins compared to [68Ga]Ga-DOTA.SA.FAPi and [177Lu]Lu-DOTA.SA.FAPi. In vivo studies revealed slower washout of [68Ga]Ga-DOTAGA.(SA.FAPi)2 within 3 h compared to [68Ga]Ga-DOTA.SA.FAPi. The tumor-to-tissue ratios of [68Ga]Ga-DOTAGA.(SA.FAPi)2 versus [68Ga]Ga-DOTA.SA.FAPi did not exhibit any significant differences. [177Lu]Lu-DOTAGA.(SA.FAPi)2 maintained a significant tumor uptake even after 96 h p.i. compared to [177Lu]Lu-DOTA.SA.FAPi. Dimeric compounds hold promise for therapy, while monomers are better suited for diagnostics. Finding the right combination is essential for effective disease management.

Identification of a mimotope of a complex gp41 Human Immunodeficiency VIrus epitope related to a non-structural protein of Hepacivirus previously implicated in Kawasaki disease.

We have previously isolated a highly mutated VH1-02 antibody termed group C 76-Q13-6F5 (6F5) that targets a conformational epitope on gp41. 6F5 has the capacity to mediate Ab dependent cell cytotoxicity (ADCC). When the VH1-02 group C 76 antibodies variable chain sequence was reverted to germline (76Canc), this still retained ADCC activity. Due to this ability for the 76Canc germline antibody to functionally target this epitope, we sought to identify a protein target for vaccine development. Initially, we interrogated peptide targeting by screening a microarray containing 29,127 linear peptides. Western blot and ELISAs were used to confirm binding and explore human serum targeting. Autoimmune targeting was further interrogated on a yeast-displayed human protein microarray. 76Canc specifically recognized a number of acidic peptides. Meme analysis identified a peptide sequence similar to a non-structural protein of Hepacivirus previously implicated in Kawasaki disease (KD). Binding was confirmed to top peptides, including the Hepacivirus-related and KD-related peptide. On serum competitions studies using samples from children with KD compared to controls, targeting of this epitope showed no specific correlation to having KD. Human protein autoantigen screening was also reassuring. This study identifies a peptide that can mimic the gp41 epitope targeted by 76C group antibodies (i.e. a mimotope). We show little risk of autoimmune targeting including any inflammation similar to KD, implying non-specific targeting of this peptide during KD. Development of such peptides as the basis for vaccination should proceed cautiously.

Xylosyltransferase Bump-and-hole Engineering to Chemically Manipulate Proteoglycans in Mammalian Cells.

Mammalian cells orchestrate signalling through interaction events on their surfaces. Proteoglycans are an intricate part of these interactions, carrying large glycosaminoglycan polysaccharides that recruit signalling molecules. Despite their importance in development, cancer and neurobiology, a relatively small number of proteoglycans have been identified. In addition to the complexity of glycan extension, biosynthetic redundancy in the first protein glycosylation step by two xylosyltransferase isoenzymes XT1 and XT2 complicates annotation of proteoglycans. Here, we develop a chemical genetic strategy that manipulates the glycan attachment site of cellular proteoglycans. By employing a tactic termed bump- and-hole engineering, we engineer the two isoenzymes XT1 and XT2 to specifically transfer a chemically modified xylose analogue to target proteins. The chemical modification contains a bioorthogonal tag, allowing the ability to visualise and profile target proteins modified by both transferases in mammalian cells. The versatility of our approach allows pinpointing glycosylation sites by tandem mass spectrometry, and exploiting the chemical handle to manufacture proteoglycans with defined GAG chains for cellular applications. Engineered XT enzymes permit a view into proteoglycan biology that is orthogonal to conventional techniques in biochemistry.

New Method for Obtaining Carboxylic Derivatives of Oxazolo[5,4-b]pyridine Based on 3-Aminopyridine-2(1H)-ones

Current methods for synthesis of oxazolo[5,4-b]- and oxazolo[4,5-b]pyridines have several limitations, such as severe reaction conditions, lengthy reaction times, low yields and concurrent formation of side reaction products. This article presents the results of study focused on a one-step method for the synthesis of new derivatives of oxazolo[5,4-b]pyridine incorporating an aliphatic carboxylic group as a linker. During the investigation of acylation reactions of 3-aminopyridine-2(1H)-ones with cyclic anhydrides of dicarboxylic acids (succinic, maleic and glutaric), it was found that the monoamides formed at the initial stage undergo intramolecular cyclization yielding derivatives of oxazolo[5,4-b]pyridine. Subsequently, the reaction conditions were studied and optimized to achieve the target compounds with high yield and purity. The potential anti-inflammatory activity of the obtained derivatives of oxazolo[5,4-b]pyridine was evaluated by molecular docking method using AutoDock Vina software. Compounds 11-14b exhibited higher binding affinity with the selected target protein Prostaglandin synthase-2 (1CX2) compared to the reference anti-inflammatory drug diclofenac. Thus, taking into account the results of in silico analyses, the newly synthesized oxazolo[5,4-b]pyridine derivatives based on 3-aminopyridine-2(1H)-ones are promising candidates for further investigation of their potential anti-inflammatory activity through in vivo methods.

Multitargeted molecular docking and dynamics simulation of thymol-based chalcones against cancer protein markers: Synthesis, characterization, and computational study

Cancer prevention has become a significant public health concern in the 21st century, ranking as the second leading cause of global mortality following cardiovascular diseases. Despite prominent advancements in treatment, addressing cancer remains a substantial public health challenge, necessitating precise interventions tailored to diverse cancer types. The targeting of Epidermal Growth Factor Receptor (EGFR) has emerged as a fundamental strategy in modern cancer therapy due to its critical role in oncogenesis. Chalcones, a subclass of flavonoids, are promising anticancer agents due to their ability to target multiple cellular pathways implicated in cancer progression. The presence of α, β-unsaturated carbonyl moiety is a key structural feature attributed to their biological activity. This study presents an efficient synthesis approach for chalcone derivatives 4a-f designed from natural thymol. The synthesized compounds were further characterized by HRMS, 1H and 13C NMR spectral data, and further evaluated for in silico studies through molecular docking, molecular dynamic simulation, and ADMET screening. All the designed compounds 4a-f displayed favourable physicochemical properties and ADMET profiles. Molecular docking revealed favourable interactions between compounds 4a-f and the EGFR target protein. Compound 4d (p-nitro) and 4b (p-methyl) showed the more favourable docking score with low energy conformation (-8.02 kcal/mol), (-7.42 kcal/mol) respectively compared to the standard drug Gefitinib. Molecular dynamic simulations confirmed the stability of compounds 4d and 4b, exhibiting consistent structural stability in ligand-protein complexes throughout the 100 ns simulation. Acceptable RMSF values for amino acid residues indicated structural integrity and a stable protein-ligand interaction. The study identified 4d and 4b as promising leads for targeting EGFR.

Role of ubiquitination in the occurrence and development of osteoporosis (Review).

The ubiquitin (Ub)‑proteasome system (UPS) plays a pivotal role in maintaining protein homeostasis and function to modulate various cellular processes including skeletal cell differentiation and bone homeostasis. The Ub ligase E3 promotes the transfer of Ub to the target protein, especially transcription factors, to regulate the proliferation, differentiation and survival of bone cells, as well as bone formation. In turn, the deubiquitinating enzyme removes Ub from modified substrate proteins to orchestrate bone remodeling. As a result of abnormal regulation of ubiquitination, bone cell differentiation exhibits disorder and then bone homeostasis is affected, consequently leading to osteoporosis. The present review discussed the role and mechanism of UPS in bone remodeling. However, the specific mechanism of UPS in the process of bone remodeling is still not fully understood and further research is required. The study of the mechanism of action of UPS can provide new ideas and methods for the prevention and treatment of osteoporosis. In addition, the most commonly used osteoporosis drugs that target ubiquitination processes in the clinic are discussed in the current review.

Integrating network pharmacology and experimental verification to reveal the anti-inflammatory ingredients and molecular mechanism of pycnogenol.

Introduction: Pycnogenol (PYC), a standardized extract from French maritime pine, has traditionally been used to treat inflammation. However, its primary active components and their mechanisms of action have not yet been determined. Methods: This study employed UPLC-MS/MS (Ultra-high performance liquid chromatography-tandem mass spectrometry) and network pharmacology to identify the potential active components of PYC and elucidate their anti-inflammatory mechanisms by cell experiments. Results: 768 PYC compounds were identified and 19 anti-inflammatory compounds were screened with 85 target proteins directly involved in the inflammation. PPI (protein-protein interaction) analysis identified IL6, TNF, MMP9, IL1B, AKT1, IFNG, CXCL8, NFKB1, CCL2, IL10, and PTGS2 as core targets. KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis suggested that the compound in PYC might exert anti-inflammatory effects through the IL17 and TNF signal pathways. Cell experiments determined that PYC treatment can reduce the expression of IL6 and IL1β to relieve inflammation in LPS (lipopolysaccharide)-induced BV2 cells. Conclusion: PYC could affect inflammation via multi-components, -targets, and -mechanisms.

Antifungal Potential of Endophytic Metabolites Derived from Staphylococcus: An In-Vitro and In-Silico Approach

Introduction: Nature is full of surprises; it gives us problems along with solutions, but the only condition is that it needs to be explored. The ability of endophytes to tackle pathogens is one such example that falls within the context of the current work. In the current study, we have assessed the antifungal potential of endophytic bacterial metabolites of medicinal importance through in-vitro and in-silico studies. Materials and Methods: Bioactive metabolites from Staphylococcus species, an endophytic bacterium, were extracted to assess their antifungal potential through disc diffusion assays and minimum inhibitory concentration determination. Gas Chromatography-Mass Spectroscopy characterized the diverse composition of the endophytic extracts. The interactions between these metabolites and target proteins, such as CYP51B in Aspergillus fumigatus, were revealed by in-silico studies, which included molecular docking and dynamics simulations. This provided a thorough understanding of the antifungal qualities inherent in endophytic bacterial metabolites. Results: The research findings highlighted that the zone of inhibition (ZOI) exhibited by the crude extract from Staphylococcus endophytes (23.6±1.24 mm) is comparable to that of the control, Voriconazole (23±0.82 mm). Additionally, the minimum inhibitory concentration of the crude extract (0.21±0.06 mg/ml) is lower than the control (0.33±0.11 mg/ml). Notably, among the 45 identified endophytic metabolites, Pyrrolo [1,2-a]pyrazine-1,4-dione, hexahydro-3- (phenylmethyl), demonstrated superior inhibition efficacy against CYP51B (PDB Id: 4UYM) of Aspergillusfumigatusascompared to Voriconazole. These findings emphasized the potential of the identified metabolite as a promising antifungal agent. Conclusion: The endophytic metabolite, Pyrrolo [1,2-a]pyrazine-1,4-dione, hexahydro-3- (phenylmethyl), showcased significant antifungal potential as a therapeutic agent against fungal infections.

FDA Approved Niraparib-based Virtual Screening and Molecular Docking Studies to Discover Novel 6NRF Protein Modulator for Ovarian Cancer

The abstract summarizes the findings of a comprehensive analysis of chemical compounds, focusing on their potential therapeutic relevance in ovarian cancer treatment. Utilizing data from the ChEMBL database, pharmacophore-based screening identified compounds with promising activity against ovarian cancer, with notable catching scores ranging from 0.556 to 1.000. Crystallographic refinement metrics highlighted improvements in structural accuracy and quality following PDB-REDO refinement, with reductions in R and R-free values and significant enhancements in bond length RMS Z-scores. Molecular docking studies revealed predicted binding affinities ranging from -9.6 to -8.4, indicating strong interactions with target proteins. ADME analysis of niraparib, a lead compound, demonstrated favorable physicochemical properties and pharmacokinetic profiles, with Lipinski, Ghose, Veber, and Egan’s rules for drug-likeness and bioavailability met. Toxicity prediction models identified potential organ toxicity endpoints, with neurotoxicity, respiratory toxicity, and immunotoxicity showing active involvement. These findings underscore the complexity of structure-activity relationships and the importance of predictive models in guiding drug discovery efforts and ensuring safety profiles. Overall, this study provides valuable insights into the landscape of PARP inhibitors and their potential in advancing personalized medicine approaches for ovarian cancer therapy.

The Effects and Mechanism of ATM Kinase Inhibitors in Toxoplasma gondii.

Toxoplasma gondii, an important opportunistic pathogen, underscores the necessity of developing novel therapeutic drugs and identifying new drug targets. Our findings indicate that the half-maximal inhibitory concentrations (IC50) of KU60019 and CP466722 (abbreviated as KU and CP) against T. gondii are 0.522 μM and 0.702 μM, respectively, with selection indices (SI) of 68 and 10. Treatment with KU and CP affects the in vitro growth of T. gondii, inducing aberrant division in the daughter parasites. Transmission electron microscopy reveals that KU and CP prompt the anomalous division of T. gondii, accompanied by cellular enlargement, nuclear shrinkage, and an increased dense granule density, suggesting potential damage to parasite vesicle transport. Subsequent investigations unveil their ability to modulate the expression of certain secreted proteins and FAS II (type II fatty acid synthesis) in T. gondii, as well as including the dot-like aggregation of the autophagy-related protein ATG8 (autophagy-related protein 8), thereby expediting programmed death. Leveraging DARTS (drug affinity responsive target stability) in conjunction with 4D-Label-free quantitative proteomics technology, we identified seven target proteins binding to KU, implicated in pivotal biological processes such as the fatty acid metabolism, mitochondrial ATP transmission, microtubule formation, and Golgi proteins transport in T. gondii. Molecular docking predicts their good binding affinity. Furthermore, KU has a slight protective effect on mice infected with T. gondii. Elucidating the function of those target proteins and their mechanism of action with ATM kinase inhibitors may potentially enhance the treatment paradigm for toxoplasmosis.

Unlocking Novel Therapeutic Avenues: Drug Repurposing and Virtual Screening for Breast Cancer Targeting the Estrogen Receptor

This study explores the potential of drug repurposing for breast cancer therapy through virtual screening of Food and Drug Administration (FDA)-approved drugs against breast cancer-related targets. The estrogen receptor alpha ligand-binding domain, a key player in breast cancer progression, served as the primary target for virtual screening. Utilizing the DrugRep Virtual Screening Server and AutoDockVina, several compounds were identified with high binding affinities to the target protein. Notably, estradiol, benzhydrocodone, and ezetimibe emerged as top hits, showcasing diverse physicochemical properties and suggesting novel therapeutic possibilities. The structural fidelity of the estrogen receptor complex was validated through PDB-REDO refinement, enhancing the reliability of the binding interactions predicted. These findings underscore the potential of drug repurposing as a strategy for uncovering new therapeutic options in breast cancer treatment, warranting further biological validation and clinical exploration

Identification and characterization of plasma proteins associated with intra-amniotic inflammation and/or infection in women with preterm labor

This study aimed to identify plasma proteins that could serve as potential biomarkers for microbial invasion of the amniotic cavity (MIAC) or intra-amniotic inflammation (IAI) in women with preterm labor (PTL). A retrospective cohort comprised singleton pregnant women with PTL (24–34 weeks) who underwent amniocentesis. Pooled plasma samples were analyzed by label-free liquid chromatography-tandem mass spectrometry for proteome profiling in a nested case–control study (concomitant MIAC/IAI cases vs. non-MIAC/IAI controls [n = 10 per group]). Eight target proteins associated with MIAC/IAI were further verified by immunoassays in a large cohort (n = 230). Shotgun proteomic analysis revealed 133 differentially expressed proteins (fold change > 1.5, P < 0.05) in the plasma of MIAC/IAI cases. Further quantification confirmed that the levels of AFP were higher and those of kallistatin and TGFBI were lower in the plasma of women with MIAC and that the levels of kallistatin and TGFBI were lower in the plasma of women with IAI than in those without these conditions. The area under the curves of plasma AFP, kallistatin, and TGFBI ranged within 0.67–0.81 with respect to each endpoint. In summary, plasma AFP, kallistatin, and TGFBI may represent valuable non-invasive biomarkers for predicting MIAC or IAI in women with PTL.