Search Results (313)

Background/Objectives: Advanced-stage hepatocellular carcinoma is characterized by a very poor prognosis; thus, highly effective medication is still needed. Often overexpressed heat shock protein 90 is a promising target due to its pivotal role in carcinogenesis. Methods: Antiproliferative effects of 246TMP-3SF5 on HepG2 and HuH-7 cells were assessed by crystal violet staining. Apoptosis was evaluated via subG1 peak, caspase-3 activity and PARP cleavage, and ferroptosis via ROS, glutathione and malondialdehyde levels. Migration was assessed by scratch assay, and in ovo models were used to study angiogenesis and drug effects on microtumors. CAM vascular networks were quantified by semi-automatic segmentation, morphometric and box-counting fractal analysis. Molecular docking and molecular dynamics simulation of heat shock protein 90 were carried out using Autodock Vina and Gromacs respectively. Results: Profound dose- and time-dependent antiproliferative effects of 246TMP-3SF5 against HCC cell lines were observed, revealing low micromolecular IC₅₀ values and selectivity for carcinoma cells with selectivity indices > 1. A significant increase in the sub-G1 peak, key effector caspase-3 activity, as well as cleavage of PARP strongly suggested apoptosis playing a crucial role in the antiproliferative effects. Additionally, HuH-7 cells revealed an elevation of reactive oxygen species and both cell lines showed significant glutathione depletion concomitant with an increase in malondialdehyde concentration upon treatment. The observed effect could be partially reversed by applying ferrostatin-1, suggesting ferroptosis as an additional relevant mode of action. Changes in the cell cycle as well as impaired tumor cell migration were observed. Upon treatment, angiogenesis was impaired and mass of microtumors was significantly reduced. Quantitative CAM analysis showed that vascularized area fraction increased in controls but decreased under both 17-AAG and 246TMP-3SF5. Likewise global mean vessel width decreased relative to controls, while box-counting dimension was reduced under 246TMP-3SF5. Molecular docking and molecular dynamics simulation analysis predicts 246TMP-3SF5 to be binding in catalytic site of heat shock protein 90. Conclusions: 246TMP-3SF5 is a promising novel inhibitor meriting further research as a potential treatment against hepatocellular carcinoma. Full article

Protein Phosphatase 5 (PP5) is an evolutionarily conserved serine/threonine phosphatase with a unique tetratricopeptide domain. It has been implicated in a wide range of cellular processes in mammals, but its function in plants is unknown. Here, we uncovered that Arabidopsis PP5 is required for immunity mediated by the nucleotide-binding leucine-rich repeat immune receptor protein SUMM2. Loss-of-function mutations in PP5 suppress the autoimmune phenotypes caused by the activation of SUMM2 due to the disruption of the MEKK1-MKK1/MKK2-MPK4 kinase cascade. Further biochemical analysis revealed that SUMM2 interacts with Heat Shock Protein 90 (HSP90) and PP5, and SUMM2 level is reduced in pp5 knockout mutant plants, suggesting that PP5 promotes the accumulation of SUMM2, likely through its association with the HSP90 chaperone complex. Full article

Heat shock protein 90 (HSP90) is a molecular chaperone essential for maintaining the stability of many oncogenic client proteins. Although several HSP90 inhibitors (HSP90i) have entered clinical trials, their use has been limited by toxicity and resistance, underscoring the need for improved therapeutic strategies. In this study, we assessed the therapeutic potential of a new HSP90i, SP11, in T-cell acute lymphoblastic leukemia (T-ALL) in vitro and in the DLA mouse model in vivo, using single-cell transcriptomic profiling. Single-cell RNA sequencing showed that SP11 treatment reduces key oncogenic drivers, including MYC, BCL2, and stemness-related genes, consistent with impaired leukemic survival programs. In the DLA mouse model, SP11-mediated HSP90 inhibition was associated with alterations in the tumor microenvironment, including increased immune cell representation and enrichment of cytokine- and antigen-presentation-related transcriptional pathways. Despite these antitumor effects, a distinct subpopulation of cells continued to express or re-express MYC and BCL2, suggesting the development of early adaptive resistance. Consistent with these findings, an SP11-resistant MOLT4 cell line maintained high levels of MYC and BCL2 at both the transcript and protein levels, maintained CD44 expression, and exhibited altered inflammatory cytokine signaling. Functional studies confirmed that pharmacological inhibition of BCL2 notably increased SP11 sensitivity, supporting a rational combination strategy. Collectively, our results show that SP11 may exert both tumor-intrinsic and immune-modulating effects and reveal transcriptionally defined adaptive cellular states linked to resistance. This study provides mechanistic in sights into responses to HSP90 inhibition and supports combination approaches for improving therapeutic outcomes in T-ALL. Full article

Allergic rhinitis (AR) is one of the most prevalent allergic disorders worldwide. Current pharmacological treatments are often limited by suboptimal efficacy and notable adverse effects. Herbal medicines, with their multi-component and multi-target therapeutic characteristics, have attracted increasing attention. Artemisia ordosica Krasch. (AOK), a traditional Chinese/Mongolian medicine has demonstrated immunomodulatory, antioxidant, and anti-inflammatory activities. The anti-AR potential of AOK extract fractions was evaluated using in vitro mast cell degranulation inhibition assays, network pharmacology analysis, molecular docking, and molecular dynamics simulations to elucidate underlying pharmacological mechanisms. The P815 mast cell model induced by compound 48/80 was employed to assess the inhibitory activity and cytotoxicity of different extract fractions. Among the tested fractions, the ethyl acetate fraction exhibited the most potent inhibitory effect on mast cell degranulation without significant cytotoxicity. Network pharmacology analysis identified 254 potential AR-related targets of AOK, with Signal Transducer and Activator of Transcription 3(STAT3), Src protein(SRC), Tumor protein 53(TP53), AKT Serine/Threonine Kinase 1(AKT1), Heat Shock Protein 90 Alpha Family Class A Member 1(HSP90AA1), Estrogen Receptor 1(ESR1), and Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha(PIK3CA) identified as key hub proteins. Gene Ontology and KEGG pathway enrichment analyses indicated that AOK primarily modulated inflammatory and oxidative stress-related processes through the lipid and atherosclerosis, hypoxia-inducible factor-1, and AGE-RAGE signaling pathways. Molecular docking and dynamics simulations demonstrated strong binding affinities and stable interactions between major active constituents, particularly hydroxygenkwanin, and key targets such as SRC. The ethyl acetate fraction of AOK extract exhibited significant mast cell degranulation inhibitory activity, likely mediated via a synergistic multi-component, multi-target mechanism involving regulation of inflammatory and immune-related signaling pathways. These findings provide a pharmacological basis for the potential application of AOK in AR treatment. Full article

Plant viruses can cause substantial yield losses, yet disease severity often varies between seasons because plants frequently experience heat or cold episodes before infection. In this study, we tested whether such temperature conditions affect the plant’s redox balance and alter its response to Tomato bushy stunt virus (TBSV) infection in Nicotiana benthamiana. Plants were exposed to short-term heat and cold stress, after which they recovered before virus inoculation. Following this, we assessed the reactive oxygen species (ROS) content, lipid peroxidation (LPO), oxidative DNA damage, stress-related proteins, redox-associated enzymes, and antioxidant metabolites. TBSV led to non-parallel ROS responses during infection, with consistently elevated hydrogen peroxide in infected plants but reduced superoxide relative to corresponding mock controls. Heat pre-exposure caused pronounced LPO that decreased further after infection, whereas cold pre-exposure stabilized malondialdehyde near levels observed at 25 °C. Both thermal stress and infection increased 8-oxo-dG and were associated with distinct changes in 8-oxoguanine glycosylase abundance. Infection strongly induced heat shock protein 90 (and moderately heat shock protein 70), while prior heat limited further chaperone induction by TBSV. These results indicate that viral infection develops within and is limited by the host’s oxidative state, where redox homeostasis may restrict infection-related processes, and infection leads to changes in this redox environment that are favorable for its development. Full article

The silkworm, Bombyx mori, is a model organism with significant agricultural and economic importance, but it is threatened by Bombyx mori nucleopolyhedrovirus (BmNPV). A crucial chaperone, heat shock protein 90 (HSP90), can also facilitate the proliferation of viruses, and our previous quantitative acetylome analysis revealed that lysines 550 and 567 in the carboxyl-terminal domain (CTD) of Bombyx mori HSP90 (BmHSP90) were significantly deacetylated following BmNPV infection, but the underlying mechanism remained unknown. In this study, deacetylation-mimetic (K to R) mutants of BmHSP90 exhibited increased dimerization and chaperone activity compared with the wild-type. In addition, the mutants also exhibited higher affinity for actin, promoting F-actin polymerization. Collectively, these changes facilitated BmNPV replication and progeny virion production. This study reveals that the deacetylation of BmHSP90 at K550 and K567 mediates crucial host–virus interactions, providing novel insights into potential antiviral strategies. Full article

Metallothioneins (MTs) and heat shock protein 70 (HSP70) are key regulators of cellular stress response and metal homeostasis and play important roles in tumor biology. The aim of this study was to examine their expression patterns and potential prognostic significance in different molecular subtypes of breast cancer (BC), with special emphasis on triple-negative breast cancer (TNBC) and the Luminal A subtype, compared with benign breast lesions (fibroadenomas). A total of 90 tissue samples were included, and the expression of MTs in the cytoplasm and nucleus and HSP70 in the nucleus of tumor cells was analyzed immunohistochemically and correlated with clinicopathological features and treatment outcomes. Distinct expression patterns of HSP70 and MTs were observed between malignant and benign samples, as well as among the analyzed molecular subtypes of BC, suggesting their involvement in cellular adaptive mechanisms associated with malignant transformation. TNBC was characterized by less favorable clinicopathological features compared to the Luminal A subtype, including higher histological grade, increased proliferative activity, and a higher incidence of recurrence and metastatic disease. Survival analyses confirmed a worse outcome for patients with TNBC, while HSP70 and MTs expression did not show independent prognostic value in multivariate models. In conclusion, although HSP70 and MTs play important biological roles in the cellular response to stress and tumor adaptation, their expression in this study does not represent an independent prognostic indicator of clinical outcome. Nevertheless, the observed expression patterns provide insight into the complex mechanisms of tumor adaptation and emphasize the need for integrative approaches in BC biomarker research. Full article

Background: The Qingyuan partridge chicken is a high-quality local chicken breed in China. Its weight gain directly affects breeding efficiency. This study used RNA sequencing to analyze gene expression dynamics in the breast muscle tissue of Qingyuan partridge chickens at 1, 35, 70, and 105 days of age. Methods: This study employed RNA-sequencing, integrated with differential expression analysis, weighted gene co-expression network analysis (WGCNA), and short time-series expression miner (STEM) analysis, to systematically investigate the transcriptomic dynamics in breast muscle tissue across four developmental stages. Results: Phenotypic analysis revealed a significant increase in both body weight (BW) and breast muscle weight with age (p < 0.05). Transcriptomic analysis identified 3521 genes specifically expressed at the age of one day compared with the other 3 ages. These were significantly enriched in pathways related to ribosomal biosynthesis, cytoskeletal regulation, and cell proliferation (p < 0.05). Turquoise and black modules were identified by WGCNA, containing 1563 hub genes, which significantly correlated with BW. Integration of differentially expressed genes and STEM analysis selected 26 BW-related key genes closely associated with muscle growth, including calmodulin 2 (CALM2), heat shock protein 90 alpha family class A member 1 (HSP90AA1), and cholinergic receptor nicotinic delta subunit (CHRND). Protein–protein interaction analysis revealed two functional networks centered around these genes. Enrichment analysis of the STEM profiles indicated that upregulated genes were significantly enriched in autophagy and the ErbB, FoxO, mTOR, and insulin signaling pathways, while genes related to the ribosome, cell cycle, and PPAR signaling pathways were downregulated. Conclusions: This study identified BW-related key genes and pathways, enriching our knowledge of the functional maintenance of chicken BW. Full article

We present a computational study that precedes the potential interactions between SARS-CoV-2 helicase (NSP13) and selected host proteins implicated in chaperone-assisted folding and polyamine metabolism. Using structure-based modelling and protein–protein docking (BioLuminate v4.6), followed by all-atom molecular dynamics (MD) simulations (GROMACS v2018.6), and comparative MM-GBSA scoring (HawkDock v2), we evaluated the stability and interface properties of NSP13 complexes with cytosolic heat shock proteins; heat shock protein 40 (HSP40), heat shock protein 70 (HSP70), heat shock protein 90 (HSP90) and the polyamine biosynthesis enzyme ornithine decarboxylase (ODC). Docking, MD, and interface analyses indicate distinct complex behaviours: HSP70-NSP13 complexes sampled compact conformations, HSP90-NSP13 ensembles displayed greater conformational heterogeneity but more favourable comparative MM-GBSA estimates, and ODC-NSP13 interfaces were comparatively well packed. Per-residue contact mapping identified a small set of recurrent NSP13 residues, Lys22 and Asn51, as putative interaction hotspots. The reported findings herein generate testable hypotheses about NSP13 recruitment of host chaperones and modulation of polyamine metabolism that may inform downstream experimental studies. Full article

Background: Atherosclerosis (AS) serves as the primary pathological basis for cardiovascular disease-related deaths worldwide, posing a severe threat to public health security. Heat shock protein 90 (HSP90) plays a crucial regulatory role in the pathological progression of AS, emerging as a potential target for anti-atherosclerosis drug development in recent years. Calenduloside E (CE) is a pentacyclic triterpenoid saponin isolated from Aralia elata (Miq.) Seem. Previous studies have confirmed its anti-atherosclerotic activity, but its weak efficacy and narrow therapeutic index limit its clinical application. In this study, the CE scaffold was hybridized with a ticagrelor-derived fragment to enhance anti-atherosclerotic activity. In this study, the CE scaffold was hybridized with a ticagrelor fragment to achieve improved activity. Methods: Based on the principle of molecular hybridization, CE was linked to the active fragment of ticagrelor via a PEG chain. Ten CE derivatives were synthesized by modifying the sugar substituents. In vitro experiments were conducted to detect cytotoxicity and protective activity against ox-LDL-induced HUVECs injury. Molecular docking and Surface Plasmon Resonance (SPR) assays were used to evaluate the interaction between CE derivatives and the known target HSP90β. Combined with Microscale Thermophoresis (MST), SwissTargetPrediction, and molecular docking, other potential targets of CE derivatives were identified. Results: In the ox-LDL-induced HUVECs injury model, all compounds except C2 and C9 exhibited protective activity. Among these compounds, compound C5 exhibited the optimal protective effect, with an EC₅₀ value of 1.44 μM. Molecular docking results revealed that both C5 and CE could bind to HSP90β by forming hydrogen bonds with the key amino acid Asp93. Additionally, SPR results indicated that C5 and CE had similar binding affinities to HSP90β, with dissociation constants (K_D) of 1.73 μM and 1.72 μM, respectively. MST demonstrated that C5 binds to HSP90β with an affinity 111 times higher than that of ticagrelor. SwissTargetPrediction and molecular docking identified P2Y12 as another potential target of derivative C5. Conclusions: Compound C5 exerts protective effect against ox-LDL-induced HUVECs injury by targeting HSP90β. Its effective concentration is significantly improved compared with that of the parent CE, which provides a possibility for reducing clinical dosage and toxic side effects in subsequent studies. Furthermore, C5 may exert its effects by targeting another potential target, P2Y12, offering references for the rational design of novel anti-atherosclerotic drugs. Full article

ATP hydrolysis drives essential processes across biology, from nucleic acid translocation and conformational switching to signal transduction. The GHKL ATPase family—DNA Gyrase B, Heat Shock Protein 90 (Hsp90), Histidine Kinases, and MutL homologs—shares a Bergerat-fold that couples nucleotide binding and hydrolysis to conformational changes, dimerization, and signaling. Despite their diverse roles, GHKL proteins rely on common ATP-dependent principles. Within this family, MutLα (MLH1-PMS2 in humans, Mlh1-Pms1 in yeast) is central to eukaryotic mismatch repair, where it provides the endonuclease activity needed for strand incision and coordinates interactions with other repair partners. MutLα exemplifies how the Bergerat-fold has been adapted to regulate DNA interactions, partner communication, and protein turnover on DNA. By examining MutLα through the lens of other GHKL proteins, we can clarify how ATP binding and hydrolysis drive its conformational dynamics, nuclease activation, and regulation within its pathway, highlighting how conserved mechanistic strategies are repurposed across biological systems. Full article

Marrubium vulgare L. is a medicinal plant widely used in traditional medicine, with emerging evidence of anticancer potential. This study investigated its bioactive compounds as inhibitors of Heat Shock Protein 90 alpha (Hsp90α), a molecular chaperone essential for oncogenic protein stability. Organic and aqueous extracts were profiled using high-performance liquid chromatography–mass spectrometry (HPLC–MS), revealing a diverse phytochemical composition. Identified compounds were screened against the full-length crystal structure of Hsp90α using a structure-based computational workflow that included extra-precision and domain-specific molecular docking, molecular dynamics (MD) simulations, and MM/GBSA binding free energy calculations. Pharmacokinetic and toxicity profiles were evaluated through ADMET predictions. This study elucidated the chemical composition of the plant and identified two hit compounds: Forsythoside B bound preferentially to the middle domain, potentially interfering with client protein interactions, and chlorogenic acid targeted the C-terminal domain, which regulates dimerization and allosteric activity. Both ligands displayed stable protein–ligand interactions during MD and favorable ADMET properties. These findings provide the first integrated chemical and computational prediction framework, suggesting that some M. vulgare metabolites may interact with Hsp90, highlighting its potential as a source of novel anticancer scaffolds and laying the groundwork for experimental validation and drug development. Full article

The yield and quality of rubber tree latex are affected by environmental stresses and plant hormone stimulation. Heat shock protein 90 (HSP90) is widely involved in various developmental processes and stress responses in plants, especially in drought stress. In this study, we cloned the HbHSP90.3 gene and characterized its expression pattern in different tissues and mechanical wounding treatments of the rubber tree and found that it is highly expressed in latex and responds to mechanical wounding treatment. To reveal the roles of plant hormones and HSP90.3 protein in the drought resistance process of rubber trees. Treatment with the specific HSP90 protein inhibitor geldanamycin (GDA) and yeast expression experiments demonstrated that HbHSP90.3 has a relieving effect on water deficit in rubber trees. The expression pattern showed that the HbHSP90.3 gene was closely related to hormone signaling, especially for Indole acid (IAA) and Zeatin (ZT) induction under different plant hormone treatments. Protein interaction analysis showed that HbHSP90.3 interacted with the suppressor of the G2 allele of skp1 (HbSGT1b). Taken together, HbHSP90.3 interacts with HbSGT1b in the nucleus and plays a key role in water deficit. Full article

Macadamia integrifolia is a vital cash crop. The shells of its nuts serve multiple purposes in both agricultural practices and waste management initiatives. In this research, transcriptome analysis was carried out on three macadamia nut varieties with significantly different shell thicknesses, namely ‘A38’, ‘Guire No.1’ (‘GR1’), and HAES842 (‘842’), at the same stage of maturity. The results revealed remarkable differences in their gene expression profiles. A total of 4311 novel genes were identified, among which 1631 were functionally annotated. Analyses using Gene Ontology (GO), Clusters of Orthologous Groups (COGs), and the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that the main categories of differentially expressed genes (DEGs) were associated with plant–pathogen interactions. Additionally, 10 members of the heat shock protein 90 (MiHSP90) family were identified and classified into subgroups A, B, and C by comparing them with the HSP90 gene family members of Arabidopsis and rice. Among these, the MiHSP90.1, MiHSP90.2, and MiHSP90.9 proteins were differentially highly expressed in the three macadamia nut varieties. These findings provide fundamental insights into the regulatory mechanisms underlying shell formation in macadamia nuts. Full article

Background: Heat shock protein 90 (HSP90) is a molecular chaperone that stabilizes numerous oncogenic proteins and supports tumor survival. Small molecules targeting HSP90 offer a novel approach to overcome drug resistance and immune suppression in breast cancer. Methods: A novel thiazolyl benzodiazepine (TB) containing a hydrazone moiety was evaluated in breast cancer cell lines (ER⁺ MCF-7, TNBC MDA-MB-231, and HER2⁺ SK-BR-3). Cytotoxicity was assessed using the CCK-8 assay, followed by PCR sequencing, flow cytometry, RT-qPCR, protein profiling, and HSP90 binding assays. Results: TB showed the strongest activity in MCF-7 cells (IC₅₀ = 7.21 µM) compared to MDA-MB-231 (IC₅₀ = 28.07 µM) and SK-BR-3 (IC₅₀ = 12.8 µM) cells. Mechanistic studies showed that TB binds to HSP90 (Kd = 3.10 µM), leading to disruption of the oncogenic signal. TB induced G2/M cell cycle arrest, promoted apoptosis via Bax and Caspase-3 activation, and suppressed cancer stem cell markers (NANOG, OCT4, SOX2). Additionally, TB activated immune-related pathways via ERK/MAPK signaling and upregulated genes such as SMAD2, SMAD3, and JUN.Conclusions: TB functions as an HSP90 inhibitor with dual anticancer and immunomodulatory properties in Estrogen Receptor-Positive (ER⁺) breast cancer cells. These findings suggest that TB represents a promising scaffold for the development of multi-targeted breast cancer therapies. Full article