Search Results (731)

Tauopathies, including Alzheimer’s disease (AD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and frontotemporal lobar degeneration with tau pathology, are unified by pathogenic tau misfolding, post-translational modification, aggregation, and network-level spread. Yet decades of drug development that predominantly pursued single nodes (e.g., one kinase, one aggregation inhibitor, one monoclonal antibody epitope) have repeatedly delivered late-stage disappointments, underscoring a central lesson: tauopathy behaves less like a linear pathway and more like a coupled system of proteostasis failure, neuroinflammation, synaptic-mitochondrial stress, and metabolic dysregulation. This review examines rhizomes (notably Zingiberaceae genera such as Curcuma, Zingiber, Alpinia, Kaempferia, and Boesenbergia) as chemically diverse “multi-target platforms” whose bioactives can engage several tau-relevant nodes simultaneously. We synthesise evidence across tau phosphorylation (GSK-3β/CDK5 and upstream stress signalling), tau aggregation and seeding, autophagy-lysosome and proteasome pathways, redox-mitochondrial resilience, neuroinflammatory circuits (NF-κB/NLRP3), and neuro-metabolic signalling (insulin-PI3K-AKT, AMPK-mTOR). A translational lens is applied throughout, focusing on drug-likeness and CNS multiparameter optimisation; BBB permeability and efflux; metabolism and bioavailability constraints; and formulation strategies (nanoparticles, phytosomes, engineered exosomes) that may render rhizome-derived scaffolds more clinically plausible. We conclude that rhizomes offer credible mechanistic hypotheses for tau modulation, but progress depends on rigorous standardisation, realistic exposure matching, biomarker-driven study design, and a shift from “single-compound optimism” to network pharmacology with translational discipline. Full article

Objectives: Real-world information on relapsed and/or refractory multiple myeloma (rrMM) clinical management in Portugal is scarce. The CharisMMa Portugal study aimed to characterize rrMM patients through socio-demographic and clinical parameters and describe treatment patterns. Methods: This was an observational, cross-sectional, multicenter study with 62 rrMM patients routinely treated at seven hospitals in Portugal. Data were collected from medical records during clinical appointments (2020–2022) after written informed consent was obtained (ClincialTrials.gov ID-NCT04135963). Patients who were diagnosed with a symptomatic MM episode in the 6 months prior to study initiation and who received treatment before their last relapse episode were enrolled. Results: Most patients were male (54.8%) and living with relatives (90.3%), and almost 50% were independent. Roughly 70% of patients were classified as Revised MM International Staging System (R-ISS) Stage II at diagnosis, with a mean age of 65.76 (±9.24) years old. Most common SliM-CRAB (SLIM: sixty percent or more clonal plasma cells in the bone marrow (S), light chain ratio ≥100 (Li), and MRI-detected focal lesions (M); CRAB: hypercalcemia (C), renal insufficiency (R), anemia (A), and bone lesions (B)) signs were bone lesions (59%), and 62.9% of the patients had at least one comorbidity. At study initiation, 70.5% of patients were on second-line treatment, with monoclonal antibodies and proteasome inhibitors (PIs) + immunomodulators (IMiDs) as leading agents. Triplet regimens were the most common across all lines, while oral and oral + subcutaneous were the most prevalent routes of administration. Conclusions: Triple treatment combinations are common in rrMM management, with PIs and IMiDs frequently used, especially in first-line settings. The use of oral formulation is substantial, suggesting a step toward more patient-centric options. This characterization underscores the complexity of rrMM management and should inform stakeholders of strategies to standardize patient care across reference centers in Portugal. Full article

Bax, a key member of the B-cell lymphoma 2 (Bcl-2) protein family, is essential for inducing mitochondrial apoptosis. In this study, we employed yeast two-hybrid screening to identify ubiquitin-specific protease 49 (USP49) as a binding partner of Bax. Subsequent immunoprecipitation and glutathione S-transferase (GST) pull-down assays confirmed their direct interaction. Functional assays showed that USP49 reduces Bax polyubiquitination at multiple lysine residues within ubiquitin, with the strongest effects observed on K11, K29, K33, and K63 linkages. In contrast, its effect on K48-linked ubiquitination was weak and insufficient to influence Bax protein stability, indicating that USP49 does not regulate Bax abundance through proteasomal degradation. Instead, RT-qPCR analysis revealed that USP49 overexpression significantly increased Bax mRNA levels, and this effect was maintained under apoptosis stimuli (UV, H₂O₂, and STS), indicating transcriptional regulation largely independent of stress-induced damage, whereas its effect was modest and not statistically significant under starurosporine treatment. Collectively, these findings demonstrate that USP49 regulates Bax primarily through K29/K33/K63-linked ubiquitination and transcriptional upregulation, highlighting its role as a stress-responsive modulator of apoptosis and a potential therapeutic target in cancer. Moreover, under DNA damage condition (UV), USP49 overexpression marked enhanced apoptosis. Full article

Triploid turbot (Scophthalmus maximus) exhibit superior growth and survival, yet the molecular basis of their sterility—a key trait for aquaculture—remains largely unexplored. This study investigated ovarian development and transcriptomic profiles in diploid and triploid S. maximus at three key stages (6, 10, and 20 months post-hatch, mph) to elucidate the stage-specific molecular mechanisms underlying triploid sterility. Histological analysis revealed that diploid ovaries progressed through normal oogenesis to the early vitellogenic stage by 20 mph, whereas triploid ovaries were arrested at the oogonial stage, with only occasional primary oocytes and extensive connective tissue infiltration. Comparative transcriptomic analysis identified 13,305, 14,599, and 13,331 differentially expressed genes (DEGs) between triploid and diploid ovaries at 6, 10, and 20 mph, respectively. Functional enrichment analysis showed that DEGs were significantly associated with meiotic processes, cell cycle regulation, energy metabolism, and apoptosis. Key meiotic genes (spo11, dmc1, sycp3) were consistently upregulated in triploids across all stages, while the DNA repair gene rad51 was paradoxically downregulated, indicating attempted but aberrant meiotic initiation. Oogenesis regulators (gdf9, bmp15, pou5f3) and energy metabolism genes (ndufa11, sdha, cox5a) were significantly downregulated, whereas apoptosis-related genes (eif2ak3, apaf1) were upregulated. Notably, KEGG pathway analysis revealed stage-specific shifts from stress-induced apoptosis and p53 signaling at early stages to proteasome activation at later stages, suggesting a transition from active germ cell elimination to maintenance of cellular homeostasis in developmentally arrested ovaries. Collectively, these findings demonstrate that triploid sterility is associated with coordinated dysregulation of meiotic progression, metabolic, and apoptotic pathways, providing a high-resolution molecular framework for understanding reproductive failure in triploid fish and informing strategies for optimizing triploid production in aquaculture. Full article

Background/Objectives: This study investigates the induction of cuproptosis in A549 lung cancer cells by doxorubicin (DOX) complexes and the development of pH-responsive bovine serum albumin (BSA)-based nanocarriers for their delivery. We successfully synthesized and characterized two novel complexes: DOX–Cu, where DOX acts as a ligand for Cu(II), and DOX–BTZ, a conjugate formed between DOX and the proteasome inhibitor bortezomib (BTZ). Methods: Spectroscopic and NMR analyses were performed to confirm the formation of the complexes. In vitro assays were conducted to evaluate cytotoxicity in A549 cells, alongside assessment of DLAT aggregation as a marker of cuproptosis. The formulation of DOX into BSA nanoparticles (DOX–Cu@BSA NPs and DOX–BTZ@BSA NPs) was carried out to evaluate potential alleviation of DOX-induced cytotoxicity in cardiomyocytes in vitro. Fluorescence quenching and molecular docking studies were employed to investigate the binding interactions between the complexes and BSA. Cellular uptake experiments were performed to assess nanoparticle internalization into A549 cells. Results: Both complexes exhibited superior cytotoxicity against A549 cells compared to individual components. This enhanced cell death was associated with significant aggregation of dihydrolipoamide S-acetyltransferase (DLAT), a key marker of cuproptosis, suggesting the involvement of this copper-dependent cell death pathway. The BSA nanoparticles displayed favorable characteristics, including uniform size (~190 nm), high encapsulation efficiency (~75–79%), and colloidal stability. Crucially, they exhibited a pH-responsive drug release profile, with significantly accelerated release under acidic conditions (pH 5.7) mimicking the tumor microenvironment. Fluorescence quenching and molecular docking studies revealed strong, spontaneous binding between the complexes and BSA, primarily driven by hydrophobic interactions. Cellular uptake experiments confirmed efficient internalization of the nanoparticles into A549 cells. Conclusions: Collectively, this work offers a proof-of-concept for a strategy of utilizing BSA-based multidrug delivery systems for cuproptosis induction, offering a potential avenue to enhance therapeutic efficacy while reducing systemic toxicity in lung cancer treatment. Full article

Down syndrome (DS), caused by trisomy 21, is the most prevalent genetic condition associated with accelerated aging and near-universal development of early-onset Alzheimer’s disease (AD). Beyond gene-dosage imbalance, trisomy 21 induces widespread transcriptional, metabolic, and proteomic remodeling that establishes a chronic state of proteotoxic and oxidative stress from early development. Increasing evidence identifies DS as a disorder of proteostasis network failure, in which sustained translational pressure, redox disequilibrium, and degradation pathway insufficiency progressively erode cellular resilience. In the DS brain, persistent endoplasmic reticulum stress with PERK-dominant signaling, mitochondrial dysfunction characterized by oxidative phosphorylation deficits and excessive reactive oxygen species production, and impaired antioxidant responses create a highly vulnerable intracellular environment. Concomitantly, degradation systems become compromised: proteasomal catalytic activity declines, ubiquitin-dependent signaling is remodeled, and chronic mTOR hyperactivation suppresses autophagic and mitophagic flux. The coordinated impairment of the ubiquitin–proteasome system and autophagy establish a feed-forward cycle of proteotoxic accumulation and redox amplification. Within this framework, Alzheimer-like neuropathology in DS emerges not solely from amyloid precursor protein triplication but as the late manifestation of decades-long proteostasis exhaustion. Therapeutic strategies aimed at restoring global proteostasis and redox balance may therefore represent a more effective systems-level approach to mitigating neurodegeneration in DS. Full article

Bortezomib (BTZ), the first-generation proteasome inhibitor, has been approved for the treatment of relapsed, refractory, and newly diagnosed multiple myeloma. Despite its remarkable antitumor efficacy, BTZ treatment is severely limited by a high incidence of systemic adverse reactions, primarily due to its non-selective cytotoxicity toward rapidly dividing normal cells and its potent neurotoxic effects on peripheral neurons. Bortezomib-induced peripheral neurotoxicity (BIPN) manifests as neuropathic pain and sensory abnormalities, affecting up to 31% to 64% of patients and limiting BTZ’s clinical use. Currently, the underlying mechanisms of BIPN are poorly understood. To evaluate the effects of BTZ on the functions of peripheral nerves in mice, we administered an intraperitoneal injection treatment for four weeks. Results indicated that BIPN caused mechanical allodynia, gait abnormalities, and pathological changes in myelin and axons in mice. This study confirms that BTZ upregulates the expression of the activating transcription factor 3 (ATF3), which in turn mediates the increased expression of the copper transporter SLC31A1, causing dysregulation of intracellular copper ion homeostasis and subsequent copper accumulation, and ultimately inducing the development of peripheral neurotoxicity. Elevated intracellular copper concentration exerts a dual effect: it directly promotes the oligomerization of Dihydrolipoamide S-acetyltransferase (DLAT) and concurrently damages the iron–sulfur cluster protein ferredoxin 1 (FDX1), collectively triggering the onset of cuproptosis. Green tea has garnered attention for its rich content of catechins, with (−)-Epigallocatechin Gallate (EGCG) being the most abundant catechin present. This study uncovers the molecular mechanism by which EGCG inhibits BTZ-induced cuproptosis through targeted regulation of copper homeostasis. Analyses demonstrate that EGCG significantly downregulates the expression of the copper transporter SLC31A1, thereby effectively suppressing transmembrane influx of extracellular copper ions. This intervention markedly reduces intracellular copper overload, eliciting a dual regulatory effect: on one hand, the decreased copper concentration directly inhibits the oligomerization of DLAT; on the other hand, it effectively protects the iron–sulfur cluster protein FDX1 from damage. This study aims to systematically elucidate the molecular mechanisms underlying BIPN and to evaluate the therapeutic potential of EGCG in alleviating BIPN, offering a novel therapeutic strategy for the prevention and treatment of BIPN. Full article

Betaine-homocysteine methyltransferase (BHMT) is an enzyme involved in one-carbon metabolism and plays a crucial role in maintaining liver health. In this study, we investigated the impact of liver-specific deletion of BHMT on liver dysfunction using a mouse model. We generated BHMT floxed mice and bred them with albumin Cre to generate liver-specific BHMT knockout (BHMT LKO) mice. Liver tissues harvested from six-month-old chow-fed BHMT floxed and LKO mice were characterized through histological, biochemical, and molecular analyses. BHMT LKO mice displayed a complete loss of hepatic expression of BHMT mRNA, protein and enzyme activity. Histopathological analysis revealed the development of hepatic steatosis in BHMT LKO mice compared to the floxed mice. These morphological changes were supported by biochemical analysis showing elevated levels of hepatic triglycerides in conjunction with a profound decrease in the methylation potential (i.e., reduced S-adenosylmethionine (SAM): S-adenosylhomocysteine (SAH) ratio), which was mainly driven by a six- to sevenfold increase in SAH levels. BHMT LKO mice also exhibited increased lipid peroxidation and lysosomal dysfunction compared to floxed mice. Early signs of inflammation were seen in the livers of BHMT LKO mice of both sexes, as evident from significant increase in CD68-positive cells and interleukin 1β levels. Additionally, there was a moderate increase in fibrosis, as evidenced by the upregulated expression of α-smooth muscle actin and collagen II levels and the histological assessment of picrosirius red-stained liver sections of BHMT LKO mice of both sexes compared to their respective counterparts. These findings demonstrate that hepatic BHMT deficiency promotes lipid accumulation, lysosomal/proteasomal dysfunction, and early inflammatory and fibrotic changes in the liver by reducing the methylation potential. Collectively, our results underscore BHMT as a critical regulator of liver homeostasis and a potential therapeutic target in liver-related disorders. Full article

The present study investigated the effect of Ligula intestinalis L. infection on several components of the antioxidant system and on protein oxidation in the host fish, common bream Abramis brama L. In ligulosed bream, the hepatopancreatic antioxidant system response included a decrease in catalase (CAT) activity, an increase in glutathione S-transferase (GST) activity, and no change in superoxide dismutase (SOD) activity. The contents of molecular antioxidants in the organs of infected bream were inconsistent; for instance, hepatopancreatic α-tocopherol content was significantly lower, whereas retinol content was significantly higher than in uninfected individuals. In contrast, no significant differences were found in the α-tocopherol or retinol content in the skeletal muscles of infected and uninfected fish. The protein oxidation, estimated via protein carbonyl content, was unaffected by ligulosis, as was the activity of proteasomes. However, the activity of calpain, another protease, was significantly higher in the skeletal muscle of infected fish. Overall, the data reveal moderate and tissue-specific alterations in oxidative stress markers in A. brama infected with L. intestinalis, suggesting a complex host–parasite interaction that does not result in severe systemic oxidative damage under the studied conditions. Full article

Background: Idiopathic inflammatory myopathies (IIMs), characterized by muscle weakness and chronic inflammation, currently lack highly effective therapies. This study investigated the therapeutic potential and underlying mechanism of (5R)-5-hydroxytriptolide (LLDT-8), a triptolide derivative with reduced toxicity, using an experimental autoimmune myositis (EAM) mouse model and in vitro assays. Methods: Forty female BALB/c mice were randomly assigned to five groups: normal, vehicle, methylprednisolone (MP), LLDT-8 (0.0625 mg/kg), and LLDT-8 (0.125 mg/kg). EAM mice were treated with LLDT-8 (0.0625 or 0.125 mg/kg) or methylprednisolone as a positive control. Cellular experiments and molecular docking were performed to investigate potential mechanisms of LLDT-8. Results: LLDT-8 significantly attenuated clinicopathological features, including muscle weakness and pain sensitivity, while reducing serum levels of aspartate aminotransferase and lactate dehydrogenase. Histological analysis revealed that LLDT-8 reduced inflammatory cell infiltration and the presence of CD4⁺ and CD8⁺ T cells in muscle tissues. Mechanistically, LLDT-8 inhibited the expression of nucleotide-binding oligomerization domain receptor caspase recruitment domain 5 (NLRC5), a key transcriptional regulator of major histocompatibility complex-I (MHC-I). This suppression extended to downstream antigen presentation-related molecules, including the transporter associated with antigen processing and proteasome 20S subunit beta. Molecular docking further confirmed the high binding affinity of LLDT-8 to both NLRC5 and MHC-I. Conclusions: LLDT-8 alleviates inflammatory muscle injury by targeting the NLRC5/MHC-I signaling axis, suggesting it may be a promising therapeutic candidate for IIMs. Full article

Euonymus bungeanus is a highly valued ornamental tree/shrub species widely utilized in landscaping and afforestation in Northeast Asia, yet molecular studies on this species remain limited due to the lack of validated reference genes for reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). In this study, 16 candidate reference genes were selected based on classical plant reference genes and our previous transcriptome data. Their expression stability was comprehensively evaluated using 64 samples collected from diverse tissues and plants subjected to various abiotic stress/hormone treatments across multiple time points. Across all samples analyzed, PBG1 (20S proteasome beta subunit G1) exhibited the highest overall expression stability, followed by VAPD (vacuolar ATP synthase subunit D) and EIF4A (eukaryotic translation initiation factor 4A). For tissue-specific analysis, TSR2 (pre-rRNA-processing protein), VAPD, and PBG1 demonstrated the greatest stability. Under specific stress conditions, PBG1 and EIF4A were identified as the most stable genes under low- and high-temperature conditions. PP2A (protein phosphatase 2A) and TUB6 (beta-6 tubulin) were optimal for drought stress, while TSR2, SRP (nuclear speckle splicing regulatory-like protein), and PBG1 exhibited superior stability under salt stress. These findings establish a validated panel of reference genes enabling accurate and reliable gene expression normalization in E. bungeanus, thereby facilitating future functional genomics studies in this economically and ecologically important species. Full article

Although LRRK2 mutations modulate systemic glucose homeostasis and metabolic dysfunction precedes Parkinson’s disease (PD) motor symptoms; the way in which pathogenic variants of LRRK2 disrupt astrocytic glucose metabolism and organellar homeostasis remains poorly understood. Here, we demonstrate that LRRK2-I1371V mutation causes profound metabolic and organellar dysfunction in LRRK2-I1371V PD-iPSC-derived astrocytes and U87 cells overexpressing I1371V variant. LRRK2-I1371V astrocytes exhibit significantly reduced GLUT1 expression and cell surface localization, resulting in impaired glucose uptake and decreased lactate production. This metabolic insufficiency correlates with cascading mitochondrial dysfunction, characterized by membrane depolarization, elevated reactive oxygen species, enhanced ubiquitination and reduced proteasomal activity. Reduced LAMP1/LAMP2 expression, impaired lysosomal acidification, and selective cathepsin D deficiency were observed. Accumulation of undegraded cargo was confirmed by transmission electron microscopy upon α-synuclein exposure. ER stress was evident by upregulation of GADD34/CHOP, increased phospho-PERK, and reduced nascent protein synthesis. Increased ER–mitochondrial contact via MAMs and enhanced STIM1-ORAI3 clustering reflect compensatory but ultimately insufficient responses to energy stress. Our results reveal that LRRK2-I1371V induces glucose uptake deficits, leading to energy depletion and integrated ER–mitochondria–lysosome dysfunction, thus indicating restoration of astrocytic metabolic capacity as a potential therapeutic strategy for LRRK2-associated PD. Full article

Background/Objectives: EBV is an oncogenic virus linked to NPC and GC, driving cisplatin resistance. Resveratrol has anticancer activity, but its targets and mechanisms against EBV-positive cancers remain unclear. Methods: We assessed resveratrol’s cytotoxicity in EBV-positive cells via functional assays, identified targets by chemical similarity search and molecular docking, and validated PTPN1 via in vitro experiments and nude mouse xenograft models. Results: Resveratrol inhibited EBV-positive cell viability in a time- and concentration- dependent manner, with IC50 values ranging from 35.85 to 145.7 μM across different cell lines at 24–72 h. Apoptosis rates increased by approximately 2- to 4-fold after 80 μM resveratrol treatment for 24 h. Resveratrol directly targeted PTPN1 (docking score = −4.89) and promoted its degradation via the proteasome pathway, as MG132 reversed this effect. Notably, resveratrol synergized with cisplatin (combination index < 1) to reverse cisplatin resistance in both in vitro and in vivo models. Furthermore, resveratrol induced EBV lytic reactivation through ROS production, as evidenced by the increased expression of BZLF1, BMRF1, and BALF2, which was attenuated by the ROS scavenger NAC. Conclusions: Our findings identify PTPN1 as a direct anticancer target of resveratrol in EBV-positive cancers. Resveratrol enhances the therapeutic efficacy of cisplatin via PTPN1 proteasomal degradation and induces EBV lytic reactivation through ROS accumulation. These findings provide a mechanistic basis for the development of novel combination therapies targeting EBV-associated malignancies. Full article

Carbon dots offer excellent physico-chemical properties and biocompatibility for cancer theranostics systems, either as therapeutic agents themselves, or as potential drug carriers. It is, however, postulated that the drug carrier affects the mechanism of action and intracellular target molecules of a drug. Therefore, in the present study, we systematically evaluated protein alterations in HeLa cervical cancer cells after treatment with sulfur-doped carbon dots (S-CDs). Synchrotron Radiation μFTIR spectroscopy and label-free LC–MS/MS proteomics integrated with bioinformatics were used to assess molecular changes. μFTIR revealed a shift and increased intensity of α-helices, indicating structural changes in proteins as a result of the interaction between S-CDs and cells. Proteomic analysis identified 122 statistically significant (p ≤ 0.05) proteins with increased abundance and 61 with decreased abundance following S-CD exposure, many of which possess high α-helix content, consistent with μFTIR findings. Functional analyses showed that up-regulated proteins were enriched in molecular adaptor, transporter, and transcription regulator activities, particularly those involved in RNA metabolism and translation. Down-regulated proteins were dominated by protein-modifying enzymes and cytoskeletal components. Pathway enrichment analysis indicated alterations in mRNA processing, ribosomal pathways, translation factors, aminoacyl-tRNA biosynthesis, and proteasome degradation. Key hub proteins included ribosomal proteins and translation initiation factors. S-CD treatment led to opposite regulation of many proteins compared to their regulation in untreated HeLa cells including down-regulation of ribosomal proteins (RPS27L, RPS19, and RPS5), aminoacyl-tRNA biosynthesis proteins (IARS1, LARS1, and MARS1), and proteasome degradation proteins (PSMD2, PSMD3, and PSMD11), which aligns with the observed cytotoxic effect of S-CDs on cervical cancer cells. Overall, these results highlight significant proteomic and structural protein changes induced by S-CDs and support their potential for cervical cancer treatment, warranting further investigation of this nanomaterial’s biological applications. Full article

Parkinson’s disease (PD) is characterized by the progressive degeneration of dopaminergic neurons and the accumulation of α-synuclein-rich inclusions, largely resulting from impaired protein clearance mechanisms. Copper is an essential redox-active metal in the central nervous system (CNS), but alterations in its homeostasis can promote oxidative stress, mitochondrial dysfunction, and proteostatic failure. In vitro studies indicate that copper can promote α-synuclein misfolding, enhance oxidative stress, and interfere with both the ubiquitin–proteasome system (UPS) and the autophagy–lysosome pathway (ALP). In this review, we critically evaluate mechanistic evidence from cellular models, integrating available animal and clinical data to assess the biological significance of copper-mediated impairment of α-synuclein clearance. We highlight the current research, identify methodological limitations, and discuss whether copper imbalance acts as a primary pathogenic trigger or as a disease-modifying amplifier of proteostatic failure. Furthermore, we consider the translational implications of selectively modulating intracellular copper pools as a therapeutic strategy in PD. Finally, we will highlight unresolved issues, methodological limitations, and emerging targeted therapeutic prospects. Full article