Search Results (799)

Understanding how redox-active ligands coordinate to metal centers of different oxidation states is essential for applications ranging from metal remediation and recycling to drug discovery. In this study, coordination complexes of nickel(II), copper(II), and zinc(II) chloride salts were synthesized by mixing the salts with either arylazoformamide (AAF) or arylazothioformamide (ATF) ligands in toluene or methanol. The AAF and ATF ligands coordinate through their 1,3-heterodienes, N=N–C=O and N=N–C=S, respectively, and, due to their known strong binding, the piperidine and pyrrolidine formamide units were selected, as was the electron-donating methoxy group on the aryl ring. A total of 12 complexes were obtained, representing potential chelation events from ligand-driven oxidation of zerovalent metals and/or coordination of oxidized metal salts. The X-ray crystallography revealed a range of coordination patterns. Notably, the Cu(II)Cl₂ complexes, in the presence of ATF, produce [ATF-CuCl]₂ dimers, supporting a potential reduction event at the copper, while other metals with ATF and all metals with AAF remain in the 2+ oxidation state. Hirshfeld analysis was performed on all complexes, and it was found that most interactions across the complexes were dominated by H…H, followed by Cl…H/H…Cl, with metals showing very little to no interaction with other atoms. Spectroscopic techniques such as UV–VIS absorption, NMR (when diamagnetic), and FTIR, in addition to electrochemical studies support the metal–ligand coordination. Full article

Periodontal disease is a prevalent inflammatory disorder that can lead to severe oral complications. Recent studies increasingly underline the role of endoplasmic reticulum (ER) stress in its pathogenesis. Experimental models using inflammatory agents such as lipopolysaccharide (LPS), tumor necrosis factor-alpha (TNF-α), and ligature-induced periodontitis in rodents, as well as chemical hypoxia, have consistently demonstrated the activation of unfolded protein response (UPR) pathways in periodontal cells. Key ER stress markers, including CHOP, GRP78, PERK, and ATF6, were upregulated in periodontal ligament cells, stem cells, and gingival epithelial cells under these conditions. While ER stress in periodontitis is primarily associated with detrimental outcomes such as apoptosis and inflammation, it may also have a physiological role in bone remodeling via the PERK-eIF2α-ATF4 axis. Importantly, several ER stress-modulating agents—such as oridonin, melatonin, and exosomes derived from M2 macrophages—have shown therapeutic potential by reducing stress marker expression and limiting periodontal damage. These findings suggest that targeting ER stress may offer a novel therapeutic strategy. Future human studies are essential to determine whether a combined approach targeting inflammation and ER stress could more effectively halt or reverse periodontal tissue destruction, while also assessing the long-term safety of ER stress modulation. Full article

Background/Objectives: Prenatal exposure to famine can lead to lasting health effects through changes in DNA methylation. This study aims to evaluate the impact of prenatal exposure to the Chinses Great Famine (1959–1961) on human epigenome and the subsequent influence on blood lipids. Methods: We conducted an epigenome-wide association study (EWAS) of peripheral blood-based DNA methylation and prenatal exposure to the Chinese Great Famine as well as blood lipids among eight participants exposed to famine and eight sex-matched participants (born ≤ 3 years after the famine). Genome-wide DNA methylation sites were profiled using the Illumina EPIC BeadChip, which covers 850K methylation positions. Results: After EWAS analyses, seven probes in genes C8orf31, ELAVL1, U6, GBA2, SHOX2, SLC1A4, and NPHP4 reached p < 1 × 10⁻⁵. Of these, famine exposure was associated with decreased methylation levels of a GBA2 exonic probe cg08258661 (p = 4.9 × 10⁻⁶). After false discovery rate (FDR) correction, pathway enrichment analyses for genes harboring nominally significant (p < 0.05) probes identified 44 significant pathways (q < 0.05), and 5 pathways were related to lipid metabolism. After FDR correction in each pathway, probes cg02622866 (5’UTR of ATF2, p = 1.09 × 10⁻³), cg07316730 (body of GRB2, p = 1.32 × 10⁻³), and cg01105385 (body of PIK3R1, p = 1.94 × 10⁻³) in the PI2K-Akt signaling pathway were associated with blood LDL-C (q ≤ 0.04); probes cg09180702 (3’UTR of PIGQ, p = 9.21 × 10⁻⁵, and q = 0.04) and cg01421548 (body of HS3ST4, p = 5.23 × 10⁻⁵, and q = 0.01) in the metabolism pathway were associated with blood LDL-C and HDL-C, respectively; In addition, probe cg08460387 (5’UTR of MAN1C1, p = 1.09 × 10⁻⁴, and q = 0.02) in the vesicle-mediated transport pathway was associated with log-transformed blood triglycerides. Conclusions: Through an epigenetic study of the Chinese Great Famine, we identified six novel genes involved in lipid metabolism. Full article

Dry eye disease (DED) is a multifactorial condition characterized by insufficient tear film stability and ocular discomfort. Conventional artificial tears offer limited efficacy due to short precorneal residence time. This study aimed to develop and optimize ion-sensitive in situ gelling formulations based on low-acyl gellan gum (GG) and arabinogalactan (AG) to enhance retention and therapeutic efficacy in DED. Various buffer systems were screened to identify optimal gelation conditions upon interaction with artificial tear fluid (ATF). Formulations were characterized by pH, osmolality, wettability, thermal behavior, viscosity, and viscoelastic properties. A Design of Experiments (DoE) approach was employed to understand the influence of GG and AG concentrations on rheological behavior. The selected formulation, GG(0.1%)/AG(0.2%), demonstrated a significant viscosity increase upon ATF dilution, suitable viscoelastic properties, enhanced mucoadhesion compared to hyaluronic acid, improved ferning patterns, no cytotoxic effects, and stability over time. In vivo studies in rabbits confirmed prolonged precorneal retention of the fluorescently labeled formulation. These results suggest that the GG/AG-based hydrogel is a promising strategy for improving the performance of artificial tears in DED treatment. Full article

Background/Objectives: Taraxacum officinale F.H.Wigg. (Asteraceae), an edible plant and commonly used Chinese herbal medicine, has significant anti-inflammatory and antioxidant effects in the form of its root water extract (TRWE). Therefore, this study was designed to elucidate the principal pharmacological effects and underlying mechanisms of water extract from Taraxacum roots (TRWE) against cisplatin-induced nephrotoxicity through an integrated approach combining network pharmacology and experimental validation. Methods: Mechanistic prediction was performed using network pharmacology, molecular docking, and GeneMANIA-based functional analysis, followed by experimental validation via H&E staining, TUNEL, biochemical assays (blood urea nitrogen, BUN; creatinine, CRE; malondialdehyde, MDA; superoxide dismutase, SOD; and catalase, CAT), and Western blotting. Results: Network pharmacology identified 52 kidney injury-associated targets of Taraxacum. Functional enrichment analysis indicated their roles in apoptosis and endoplasmic reticulum stress, particularly through the PERK-mediated UPR pathway, suggesting the PERK/eIF2α/ATF4 axis as a potential key regulatory node. Animal experiments suggested that 100, 200, and 400 mg/kg inhibited cisplatin-induced increases in BUN, CRE, and MDA; restored SOD/CAT levels; and alleviated kidney apoptosis and endoplasmic reticulum stress via the PERK/eIF2α/ATF4 pathway. Molecular docking suggested strong binding of phytochemicals (caftaric acid, CTA; chlorogenic acid, CGA; caffeic acid, CA; and cichoric acid, CCA) to PERK, eIF2α, and ATF4. Conclusions: This study predicts that the PERK/eIF2α/ATF4 signaling pathway may be a critical mediator of TRWE’s potential renoprotective effects against cisplatin-induced acute kidney injury, offering a potential theoretical basis for further mechanistic exploration. Full article

An 8-week feeding trial was conducted to evaluate the potential of dietary soy isoflavones (SIF) to counteract growth inhibition, oxidative stress, endoplasmic reticulum stress, and inflammation induced by oxidized fish oil in Monopterus albus (initial body weight: 26.0 g). The fish were reared in outdoor pond-based net cages (2.0 m × 1.5 m × 1.5 m; 3 cages per treatment, 50 fish per cage) and fed five isonitrogenous and isolipidic experimental diets: a control diet (CON) containing 2.2% fresh fish oil, and oxidized fish oil diets (2.2% oxidized oil) supplemented with 0 (SIF0), 25 (SIF25), 50 (SIF50), or 100 (SIF100) mg/kg SIF. The fish were fed to satiation daily at 4:00 pm at a rate of 3–5% of initial body weight. Compared with the CON group, the SIF0 group showed significantly reduced growth performance, with a final weight gain rate of 84.13%, and decreased intestinal digestive enzyme activity. Hepatic superoxide dismutase (SOD) and catalase (CAT) activities declined to 1.78 U/mgprot and 4.13 U/mgprot, respectively, while serum glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) levels increased to 24.95 U/L and 37.56 U/L. The SIF0 diet also up-regulated the expression of hepatic endoplasmic reticulum stress-related genes (perk, ire1, atf6) and pro-inflammatory genes (tnfα, il-1β). Dietary SIF supplementation alleviated these adverse effects, with the most pronounced improvements observed at 50 mg/kg SIF based on overall performance. These results demonstrate that SIF can serve as a functional feed additive to mitigate oxidative stress and related metabolic disorders in M. albus. Full article

Astragali radix (AR) is a traditional Chinese herbal medicine derived from the roots of Astragalus membranaceus and A. mongholicus. AR exhibits a wide range of pharmacological activities, such as cardioprotective, hypoglycemic, antitumor, antiviral, and multi-organ restorative effects. Nearly 400 bioactive compounds have been identified in AR by phytochemical investigations, with astragalus polysaccharides (APS), astragalosides (I–IV), formononetin (FMN), and calycosin (CA) established as principal bioactive constituents. These components exhibit multifunctional mechanisms encompassing antioxidative stress, apoptotic suppression, autophagy regulation, anti-inflammation, and immune regulation, thereby exerting significant protective effects on critical organ systems such as the cardiovascular, renal, neural, hepatic, gastrointestinal, and immune systems. This review synthesized research over the past three decades, elucidating the organ protective mechanisms of AR through phytochemical profiling. Key findings demonstrated that FMN-mediated Nrf2 pathway activation could attenuate reactive oxygen species (ROS) generation, while astragaloside IV (AS-IV) could suppress endoplasmic reticulum stress by inactivating the PERK/ATF6/CHOP axis to ameliorate apoptosis. Additionally, comprehensive safety assessment and pharmacokinetic analysis also substantiated favorable bioavailability and toxicological profiles. To sum up, these findings provide a comprehensive theoretical basis and offer innovative strategies for preventing and treating complex diseases associated with multi-organ dysfunction, thereby facilitating future clinical applications. Full article

The perturbation of ER homeostasis by viral infection gives rise to the unfolded protein response (UPR), characterized by the activation of three signaling pathways. PERK, IRE1, and ATF6 have been identified as the primary mediators responsible for restoring homeostasis or leading to apoptosis in response to stress. Alphaarterivirus equid, known as equine arteritis virus (EAV), is a RNA virus with importance in the equine industry that could persist in semen and lead to abortions in pregnant mares. The present article explores the consequences of in vitro infection with the EAV Bucyrus strain on UPR. Employing RT-PCR, qPCR and Western blot, our investigation has revealed the activation of PERK and IRE1α pathways, whilst ATF6 has been suppressed. Furthermore, the p38α MAPK, caspase-12, and CHOP genes were found to be upregulated, demonstrating the induction of apoptosis. Finally, in the inhibition experiments, the PERK pathway was found to be implicated in the modulation of viral replication in the initial phases of infection. Conversely, the IRE1α pathway was identified as the predominant UPR pathway in EAV replication, as evidenced by the complete inhibition of replication observed in these experiments. Consequently, the further exploration of this UPR pathway is necessary to determine whether it can effectively suppress EAV replication. Full article

Background: Metabolic stress from amino acid (AA) insufficiency is increasingly linked to pathological angiogenesis, but specific essential AA (EAA) roles remain undefined. Neovascular age-related macular degeneration (AMD), a major cause of blindness driven by aberrant ocular neovascularization, has limited efficacy with current VEGFA-targeting therapies. We sought to identify specific EAAs that regulate pathological angiogenesis and dissect their mechanisms to propose new therapeutic strategies. Methods: Human retinal microvascular endothelial cells (HRMVECs) were used to identify angiogenesis-regulating amino acids through systematic EAA screening. The molecular mechanism was investigated using shRNA-mediated knockdown of key stress response regulators (HRI, PKR, PERK, GCN2) and ATF4. Angiogenesis was assessed via tubule formation and migration assays. Therapeutic potential was examined in a laser-induced choroidal neovascularization (CNV) mouse model, evaluated by fluorescein angiography and histomorphometry. Results: Deprivation of methionine, lysine, and threonine potently induced capillary-like tube formation (p < 0.01). Mechanistically, restriction of these three EAAs activated HRI and GCN2 kinases, converging on eIF2α phosphorylation to induce ATF4 and its target VEGFA. Dual, but not single, knockdown of HRI and GCN2 abolished eIF2α-ATF4 signaling and angiogenic responses. Restricting these EAAs exacerbated CNV area in mice. Conclusions: Our findings reveal a coordinated HRI/GCN2-ATF4-VEGFA axis linking EAA scarcity to vascular remodeling, establishing proof-of-concept for targeting this pathway in CNV. This work highlights the therapeutic potential of modulating specific AA availability or targeting the HRI/GCN2-ATF4 axis to treat CNV. Full article

Ethanol is a known neurotoxic agent that induces endoplasmic reticulum (ER) stress and apoptosis in nerve cells. The transcription factor CREB is crucial for cell survival under stress; however, its involvement in ethanol-induced endoplasmic reticulum (ER) stress remains poorly understood. We examined the effects of ethanol on wild-type PC12 cells and CREB-overexpressing PC12-CREB cells. Cell viability was evaluated by ATP assays, apoptosis was detected by Hoechst staining, and key proteins involved in ER stress and apoptotic signaling were analyzed by Western blot analysis. Ethanol treatment decreased cell viability and increased apoptosis in wild-type PC12 cells in a time-dependent manner. In contrast, PC12-CREB cells-maintained viability and showed significantly lower apoptotic cell numbers. Ethanol activated markers of ER stress (BiP, CHOP, ATF6) and pro-apoptotic pathways (phosphorylation of JNK and p38 MAPK) in wild-type cells. In CREB-overexpressing cells, CHOP induction and JNK activation were decreased, while the expression of the anti-apoptotic protein Mcl-1 was increased. CREB overexpression protects against ethanol-induced ER stress and apoptosis. This protective effect is mediated through modulation of unfolded protein response (UPR) signaling and regulation of pro-and anti-apoptotic gene expression. These findings underscore a potential role for CREB in attenuating ethanol-induced neurotoxicity. Full article

JUNB and JUND are two transcriptional factors (TFs) of increased interest in cancer, regulating the expression of genes associated with survival, proliferation, differentiation, migration, invasion, angiogenesis, adhesion, apoptosis, and cell cycle regulation. Together with c-JUN, they constitute the JUN family of TFs, acting as downstream effectors of the MAPKs, with established roles in carcinogenesis, disease progression, metastasis, and therapy resistance. Their phosphorylation leads to the formation of dimeric complexes with other TFs (from the JUN, FOS, or ATF families), thereby assembling the AP-1 complex, which exerts multifaceted influences on both normal and cancerous cells. JUNB and JUND are credited with both tumor-suppressing and oncogenic roles, since the outcome of their activation relies on the specific cancer type, disease stage, intracellular localization, and the expression of interacting cofactors. This narrative review explores the current understanding of JUNB and JUND roles within urological cancers (prostate, bladder, renal, and testicular cancer) as these malignancies, while distinct, share common genetic and/or environmental risk factors and varying degrees of androgen receptor (AR) dependency. The study discusses commonalities and differences in the expression patterns, mechanisms, and clinical implications of JUNB and JUND across urological cancers, thus highlighting their potential as prevention, diagnosis, prognosis, and treatment targets. Full article

Follicular development is recognized as a highly complex biological process regulated by multiple factors. Thyroid hormone (TH) is considered one of the key regulators of female reproduction, and its dysregulation can significantly impair follicular development. Epigallocatechin gallate (EGCG), the main active component of green tea, possesses strong antioxidant properties. Numerous studies have demonstrated that EGCG positively influences reproductive function in both humans and animals. However, whether EGCG directly affects follicular development under conditions of TH dysregulation remains poorly understood. The primary objective of this study was to investigate the impact of hyperthyroidism on ovarian development, examine whether EGCG could mitigate the adverse effects of TH dysregulation, and elucidate the underlying molecular mechanisms. In the T₄-induced hyperthyroidism rat model, ovarian tissues were serially sectioned for Hematoxylin-Eosin (HE) and Masson’s trichrome staining to assess morphological changes, and follicle numbers were quantified at each developmental stage. Granulosa cell (GC) viability, proliferation, and apoptosis induced by T₃ were evaluated using CCK8, EdU, and TUNEL assays, respectively. Antioxidant enzyme activity was measured, and the expression levels of related proteins were analyzed via Western blotting. Results showed that hyperthyroidism altered ovarian structure, significantly increasing the number of atretic follicles. Levels of antioxidant enzymes, including Superoxide Dismutase (SOD), Glutathione Peroxidase (GSH-PX), and Catalase (CAT), were markedly decreased, whereas the lipid peroxidation product malondialdehyde (MDA) was significantly elevated. Furthermore, all ERS-related proteins, phosphorylated Eukaryotic Initiation Factor 2 Alpha (p-eIF2α), Activating Transcription Factor 4 (ATF4), C/EBP homologous protein (CHOP), and Caspase-3, were upregulated, accompanied by decreased glucose-regulated protein 78 (GRP78) expression. Treatment with EGCG alleviated these detrimental effects of hyperthyroidism. At the cellular level, high concentrations of T₃ reduced GC viability and proliferation while increasing apoptosis. Reactive oxygen species levels were elevated, and GRP78 expression was decreased. Notably, all T₃-induced effects were reversed by EGCG treatment. In summary, this study demonstrates that hyperthyroidism induces oxidative stress in GCs, which triggers endoplasmic reticulum stress via the eIF2α/ATF4 pathway and leads to apoptosis. EGCG mitigates apoptosis by enhancing antioxidant capacity, thereby preserving ovarian function. These findings establish EGCG as a protective agent for maintaining ovarian health and fertility. Full article

Background: Gastrointestinal neuroectodermal tumour (GNET), also known as clear cell sarcoma (CCS) of the gastrointestinal tract, is a rare neural crest-derived malignancy characterized by EWSR1-ATF1 or EWSR1-CREB1 fusions. Due to its rarity, there is limited evidence and no established guidelines for standard management. GNET is aggressive, with high rates of local recurrence, metastasis, and mortality. Case Presentation: We report the case of a 46-year-old woman with a family history of gastrointestinal cancers who was diagnosed in 2020 with an intestinal GNET. She underwent a segmental enterectomy as the first step of multimodal therapy. After three years of follow-up, she developed hepatic and peritoneal metastases. In November 2023, she began combined therapy with the anti-VEGF tyrosine kinase inhibitor cabozantinib and the immune checkpoint inhibitor nivolumab. The patient has maintained stable disease for 18 months with good tolerance and no adverse events. Molecular analysis of the tumour, which showed an EWSR1-CREB1 fusion, supported the selection of targeted therapy and immunotherapy as the preferred treatment approach. Conclusions: Immunotherapy and targeted therapy show promise for GNET/CCS treatment, but clinical standards are lacking, and evidence comes primarily from case reports. Additional data are needed to determine the best sequence and combination of therapies for this very rare disease. Full article

Porcine Teschovirus (PTV) is a highly prevalent pathogen within swine populations, primarily associated with encephalitis, diarrhea, pneumonia, and reproductive disorders in pigs, thereby posing a significant threat to the sustainable development of the pig farming industry. In this study, a novel strain of PTV was isolated from the feces of a pig exhibiting symptoms of diarrhea, utilizing PK-15 cell lines. The structural integrity of the viral particles was confirmed via transmission electron microscopy, and the viral growth kinetics and characteristics were evaluated in PK-15 cells. High-throughput sequencing facilitated the acquisition of the complete viral genome, and subsequent phylogenetic analysis and full-genome alignment identified the strain as belonging to the PTV 2 genotype. Further investigation revealed that infection with the PTV-GXLZ2024 strain induces phosphorylation of the eukaryotic translation initiation factor 2α (eIF2α) in PK-15 cells, indicating activation of the unfolded protein response (UPR) through the PERK pathway, with minimal involvement of the IRE1 or ATF6 pathways. Notably, ATF4 protein expression was progressively downregulated throughout the infection, while downstream CHOP protein levels remained unchanged, indicating an incomplete UPR induced by PTV-GXLZ2024. Furthermore, PERK knockdown was found to enhance the replication of PTV-GXLZ2024. This study provides critical insights into the molecular mechanisms underlying PTV pathogenesis and establishes a foundation for future research into its evolutionary dynamics and interactions with host organisms. Full article