Search Results (42,422)

Background/Objectives: Copper is an essential trace element for physiological processes related to reproduction, but its impact on the hypothalamic–pituitary–ovarian (HPOA) axis and its specific mechanism remain unclear. Methods: In vivo study: 21-day-old female Sprague Dawley (SD) rats were randomly assigned to five groups (n = 10 per group), with all groups fed a basal diet and supplemented with CuSO₄·5H₂O to achieve copper ion concentrations of 0, 15, 30, 45, or 60 mg/kg in the diet. During the second phase of proestrus, blood samples, hypothalamic tissues, pituitary tissues, and ovarian tissues were collected. In vitro study: Primary mixed hypothalamic neurons were isolated and cultured from fetal SD rats on embryonic day 17. After identification by NSE immunofluorescence staining, six copper ion concentration groups (0, 15.6, 31.2, 46.8, 62.4, and 78 μmol/L) were established. The optimal copper concentration for cell viability and GnRH secretion was screened using CCK-8 assay (Sangon, Shanghai, China) and ELISA (Mlbio, Shanghai, China). On this basis, the cells were treated with different concentrations of PKC agonist (PMA) and PKC inhibitor (chelerythrine). Cell viability was evaluated by CCK-8 assay, the expression level of PKC was detected by Western blot, and the optimal concentration with no obvious toxicity was selected for subsequent mechanism research. Results: Dietary copper dose-dependently regulated rat puberty onset; the 45 mg/kg copper group had the earliest onset, and showed significantly increased levels of reproduction-related hormones (GnRH, FSH, LH, E₂) in serum and HPOA axis. Hypothalamic transcriptomics revealed significantly enriched GnRH signaling pathways and GABAergic synaptic pathways. Mechanistically, this copper dose upregulated hypothalamic KISS-1, GPR54, and PKC (mRNA/protein), and downregulated GABA/GABA-R. Adding 46.8 μmol/L copper (as Cu²⁺, equivalent to optimal in vivo level) could activate the KISS-1/GPR54-GnRH system in hypothalamic neurons; regulating PKC activity could synchronously affect the expression of KISS-1, GPR54, GnRH, and GABA/GABA-R, with additional copper enhancing this effect in vitro experiments. Conclusions: This study demonstrates for the first time that dietary copper at 45 mg/kg promotes puberty onset in SD rats. The mechanism involves activation of the hypothalamic PKC pathway, which inhibits GABAergic neurotransmission while activating the KISS-1/GPR54-GnRH system, thereby enhancing HPOA axis activity and gonadotropin secretion. Full article

An overwhelming majority of cancers exhibit telomere length reduction and differentiation markers consistent with a post-stem cell of origin. On the other hand, telomere shortening/damage is believed to protect cells from malignant transformation through induction of apoptosis. However, increased cancer incidence in the absence of apoptotic factors like p53 may suggest a favorable role of telomere shortening/damage in cancer development. Some findings suggest that telomere shortening may induce architectural changes in telomeric chromatin, such as those underlying the telomere position effect that support telomere maintenance of some tumors Here, we propose that several signaling pathways, in conjunction with telomere shortening/damage, may result in the release of Rap1 from telomeres. Its subsequent interaction with the embryonic stem cell marker Zscan4 may support immortalization and malignant transformation of the target cell. Full article

Type I interferons (IFN-I) are pivotal effectors of innate immunity and constitute a central axis of host defense against pathogens. Sensing of exogenous or endogenous nucleic acids by pattern-recognition receptors—exemplified by Toll-like receptors—triggers transcriptional induction of IFN-I. Engagement of the heterodimeric IFN-I receptor on nucleated cells reprograms cellular states via canonical Janus kinase–signal transducer and activator of transcription (JAK–STAT) signaling as well as STAT-independent, noncanonical pathways. This axis is tempered by multilayered regulatory mechanisms, including epigenetic remodeling, and important aspects remain incompletely defined. Dysregulation of IFN-I activity underlies diverse autoimmune disorders, notably systemic lupus erythematosus, wherein IFN-responsive gene signatures stratify disease endotypes, reflect disease activity trajectories, and predict therapeutic responsiveness. In recent years, therapeutic strategies targeting this pathway are now available: anti-IFN-I receptor therapy for systemic lupus erythematosus (SLE) and JAK inhibition for rheumatoid arthritis (RA) and giant cell arteritis (GCA). Altogether, a refined understanding of the IFN-I axis furnishes a pragmatic framework for patient stratification, response prediction, and mechanism-informed therapy design across immune-mediated diseases. Full article

Pulmonary arterial hypertension (PAH) is a devastating cardiovascular disorder caused by right heart failure leading to premature death. The TGFBR2 and BMPR-II receptors, which are members of the TGF-β receptor family, are considered promising targets for developing novel drugs in PAH. Lupeol and ψ-taraxasterol, naturally occurring triterpene molecules with proven anti-inflammatory, anti-cancer, and cardioprotective activities, hold considerable potential in the treatment of PAH. Hence, the present study aimed to evaluate the impacts of lupeol and ψ-taraxasterol isolated from Cirsium sintenisii Freyn on the TGF-β and BMP pathways, aiming to determine their therapeutic values in PAH. The effects of the compounds were extensively investigated using both in silico and wet lab experiments, including reporter assays, RT-PCR/QPCR, Western blots, and cell proliferations assays. Both lupeol and ψ-taraxasterol demonstrated interactions with the majority of components of these signaling pathways, including the TGFBR2 and BMPR-II receptors, suggesting that both compounds were capable of modulating the BMP and TGF-β pathways. Data derived from reporter assays, RT-PCR/QPCR, and Western blots demonstrated that lupeol and ψ-taraxasterol inhibited the TGF-β signaling pathway by reducing the phosphorylation of the SMAD3 protein and the expression of pai-1 transcripts. Additionally, ψ-taraxasterol enhanced BMP signaling via regulating the phosphorylation of SMAD1/5 proteins and upregulated the expression of id-1 transcripts. Finally, lupeol and ψ-taraxasterol inhibited abnormal proliferation of mutant-type (bmpr2^R899X+/-) PAMSCs stimulated with the TGF-β1 ligand with no discernible effects on wild-type cells. This is the first comprehensive report outlining the potential therapeutic effects of lupeol and ψ-taraxasterol in PAH, which may have immediate experimental and clinical applications not only in PAH but also other BMP- and TGF-β-associated disorders. Full article

Cancer cells can sustain survival independently of exogenous growth factors. To investigate their adaptation to serum deprivation, we analyzed transcriptomic responses in two cancer cell lines. Transcriptome analysis revealed upregulation of mRNAs encoding cholesterol biosynthesis enzymes. This was a critical adaptive response, as a pharmacological inhibition of the pathway with statin triggered a robust apoptotic cell death accompanied by generation of a mitochondrial reactive oxygen species. The mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of cell growth, is known to be engaged in controlling lipid biosynthesis. We detected the high polysomal and preribosomal peaks not only in serum-containing medium but also under serum deprivation, indicating a high rate of protein synthesis and ribosomal biogenesis independent of serum. In addition, the inhibition of mTOR kinase activity substantially reduced polysome abundance, with a more pronounced effect in serum-deprived cancer cells. Notably, the mTOR kinase inhibition also prevented the upregulation of the cholesterol synthesis enzyme that established a direct link between mTOR activity, protein synthesis, and cholesterol biosynthesis. Together, our results show that cancer cells adapt to serum withdrawal by activating the cholesterol synthesis pathway through mTOR-dependent regulation of gene expression and protein synthesis, underscoring a critical mechanism of survival under serum withdrawal. Full article

Cadmium (Cd), an environmental toxin, may cause neurological disorders. We studied the role and activation mechanism of FoxO3a in Cd-induced oxidative stress. In addition to oxidative stress, Cd activated the antioxidant defense system in neuronal cells. Furthermore, by using Western blot and confocal microscopy, we found that Cd induced nuclear expression of FoxO3a. Importantly, knockdown of FoxO3a significantly suppressed its target SOD2 protein expression and elevated the level of intracellular ROS, ultimately reducing cell viability in Cd-exposed neuronal cells. These results suggest the protective effect of FoxO3a is associated with oxidative stress resistance. Then, we investigated the activation mechanism of FoxO3a. Our results indicate that the nuclear expression of FoxO3a by Cd may be independent of Akt, which is generally regarded as an important negative regulator of FoxO3a. Furthermore, we found that p38 regulated the nuclear expression of FoxO3a in Cd-exposed cells. Finally, we demonstrate that the p38-FoxO3a pathway inhibits Cd-induced oxidative stress. These signaling molecules may be used as a novel biological marker of Cd-induced oxidative stress and provide potential therapeutic approaches for it. Full article

Background. Dystroglycanopathies (DGPs) constitute a set of recessive, neuromuscular congenital dystrophies that result from impaired glycosylation of dystroglycan (DG). These disorders typically course with CNS alterations, which, alongside gradual muscular dystrophy, may include brain malformations, intellectual disability and a panoply of ocular defects. In this process, the protein products of 22 genes, collectively dubbed DGP-associated genes, directly or indirectly participate sequentially along a complex, branched biosynthetic pathway. POMGNT2 and POMGNT1 are two enzymes whose catalytic activity consists of transferring the same substrate, a molecule of N-acetylglucosamine (GlcNAc) to a common substrate, the O-mannosylated α subunit of DG. Despite their presumptive role in retinal homeostasis, there are currently no reports describing their expression pattern or function in this tissue. Purpose. This work focuses on POMGNT2 and POMGNT1 expression in the mammalian retina, and on the characterization of their distribution across retinal layers, and in the 661W photoreceptor cell line. Methods. The expression of POMGNT2 protein in different mammalian species’ retinas, including those of mice, rats, cows and monkeys, was assessed by immunoblotting. Additionally, POMGNT2 and POMGNT1 distribution profiles were analyzed using immunofluorescence confocal microscopy in retinal sections of monkeys and mice, and in 661W cultured cells. Results. Expression of POMGNT2 was detected in the neural retina of all species studied, being present in both cytoplasmic and nuclear fractions of the monkey and mouse, and in 661W cells. In the cytoplasm, POMGNT2 was concentrated in the endoplasmic reticulum (ER) and/or Golgi complex, depending on the species and cell type, whereas POMGNT1 accumulated only in the Golgi complex in both monkey and mouse retinas. Additionally, both proteins were present in the nucleus of the 661W cells, concentrating in the euchromatin and heterochromatin, as well as in nuclear PML and Cajal bodies, and nuclear speckles. Conclusions. Our results are indicative that POMGNT2 and POMGNT1 participate in the synthesis of O-mannosyl glycans added to α-dystroglycan in the ER and/or Golgi complex in the cytoplasm of mammalian retinal cells. Also, they could play a role in the modulation of gene expression at the mRNA level, which remains to be established, in a number of nuclear compartments in transformed retinal neurons. Full article

Objective: T cell exhaustion is a major mechanism of immune evasion in cancer, characterized by the sustained expression of multiple inhibitory receptors. This study aimed to evaluate the expression of immune checkpoints in peripheral and tumor-infiltrating CD8⁺ T cells from cervical cancer patients. Methods: We enrolled 104 participants: 37 treatment-naïve patients, 36 treated patients, and 31 age-matched healthy donors. Peripheral blood mononuclear cells (PBMCs) were isolated from all participants. Ten cervical biopsies were collected for tumor-infiltrating lymphocyte (TIL) isolation and paraffin fixation. Immune checkpoint expression was analyzed by multiparametric flow cytometry and immunohistochemistry. Results: In peripheral CD8⁺ T cells, we found a significant upregulation of exhaustion-associated markers PD-1, TIGIT, Tim-3, and LAG-3. In the tumor infiltrating lymphocytes, these same molecules, with the addition of NKG2A, were notably upregulated further. While BTLA and NKG2A showed no systemic changes, NKG2A increased in TILs and BTLA decreased in TILs. The co-expression of PD-1 with TIGIT, Tim-3, LAG-3, and NKG2A was notably enriched between 2- and 6-fold in TILs compared with patient PBMCs. The tumor microenvironment was highly immunosuppressive, characterized by enrichment with PD-1, PD-L1, and TIGIT; TIGIT was notably upregulated in locally advanced versus early-stage tumors. Conclusions: Our findings highlight the strongly immunosuppressive environment of cervical tumors in treatment-naïve patients and the presence of elevated inhibitory checkpoint expression in peripheral blood of both pre- and post-treatment patients. These results underscore the importance of investigating immune regulation within the tumor site itself and suggest that immune checkpoint co-expression may serve as a biomarker of T cell exhaustion and therapeutic resistance. Understanding how treatment alters these pathways could guide rational combination immunotherapies to restore CD8⁺ T cell function in cervical cancer. Full article

Cancer progression in skeletal muscle (SkM) is very rare, and mechanisms remain unclear. This study assessed the potential of SkM (myocyte)-derived EVs (C2C12-EVs) as anti-cancer agents. Using murine in vitro models, we showed that following treatment with C2C12-EVs, lung carcinoma cells failed to colonise SkM cells, and that C2C12-EVs selectively exerted apoptosis on cancer cells. Uptake of C2C12-EVs by carcinoma cells caused changes in lysosomal function and mitochondrial membrane properties inducing cell death with elevated caspase 3 and 9. The C2C12-EVs also inhibited cell proliferation, affecting cell cycle arrest at S phase and inhibited cell migration. Proteomic analysis of C2C12-EV cargoes highlighted functional enrichment pathways involved in lysozyme function, HIF-1 and PI3K-Akt signalling, regulation of actin cytoskeleton, pyruvate metabolism, platelet activation, and protein processing in ER. Decorin, a muscle cell-specific cytokine released from myocytes in response to stress, was significantly enriched in C2C12-EVs and may contribute to C2C12-EVs’ inhibitory activity on cancer cells. C2C12-EVs may suppress cancer and potentially be used as therapeutic agents for cancer metastasis. Full article

Long-duration space missions expose astronauts to galactic cosmic radiation (GCR), a complex spectrum of high-charge, high-energy (HZE) ions that pose significant risks of chronic tissue injury. To model these effects, we examined intestinal outcomes in wild-type mice 5 months after low-dose (50 cGy) 33-ion mixed-field GCR simulation (GCRsim). GCRsim induced sustained DNA double-strand breaks (DSBs) and oxidative stress, as shown by elevated γH2AX foci and 4-HNE staining. Intestinal epithelial cells (IECs) exhibited pronounced senescence, marked by increased SA-β-gal activity, p16 upregulation, LaminB1 loss, and induction of senescence-associated secretory phenotype (SASP) cytokines (Cxcl10, IL-6, IL-1β, Icam1). GCRsim also elevated circulating LINE-1 DNA and reduced expression of DNA-degrading nucleases (DNase2, TREX1), indicating impaired extracellular DNA clearance. Targeted molecular study revealed persistent activation of the cGAS–STING pathway, with elevated cGAS, STING, pTBK1, pIKKα/β, and nuclear pIRF3, pIRF7, and p65, consistent with chronic innate immune signaling. Functionally, GCRsim altered nutrient absorption gene expression—upregulating glucose transporters (Slc2a2, Slc2a5, Slc5a1) and gut hormones (Cck, Gip), while downregulating cholesterol/fat transporters (Npc1, Npc1l1). Biochemical markers supported intestinal injury, with decreased serum citrulline and increased intestinal fatty acid-binding protein (I-FABP), indicating barrier compromise. Collectively, these findings demonstrate that GCRsim drives sustained intestinal dysfunction, highlighting the need for countermeasures to protect GI health during deep-space missions. Full article

Background: Colorectal cancer (CRC) is the second leading cause of cancer-related mortality worldwide. The search for effective, new antineoplastic drugs with fewer side effects for the treatment of CRC continues, with marine-derived compounds emerging as promising candidates. Objectives: This study investigates the anticancer potential of Frondanol, a nutraceutical derived from the Atlantic Sea cucumber Cucumaria frondosa, known for its potent anti-inflammatory properties. Methods: Two human CRC cell lines, Caco-2 and HT-29, were used to test the effects of Frondanol using various in vitro approaches. Results: Frondanol significantly inhibited cell viability in a dose- and time-dependent manner. At a 1:10,000 dilution, viability decreased to around 30% in Caco-2 and 20% in HT-29 after 24 h, dropping to nearly 5% at 48 h. Furthermore, a clonogenic assay showed around 50% reduction in colony formation in both cell lines. Flow cytometry-based Annexin V staining revealed that Frondanol increased early apoptosis to ~5.2% in Caco-2 and ~9.4% in HT-29 cells, while cell cycle analysis showed accumulation of the sub G0 (apoptotic) phase increasing from 1.5% to 14.7% (Caco-2) and from 1.9% to 23.8% (HT-29). At the molecular level, Frondanol treatment significantly decreased anti-apoptotic protein B-cell lymphoma (Bcl)-2 expression while increasing the expression of the proapoptotic protein Bcl-2-associated X-protein. Additionally, Frondanol markedly induced cytochrome c release from the mitochondria and activated caspase-9, caspase-7, and caspase-3 after treatment, alongside cleavage of the caspase-3 substrate poly (ADP-ribose) polymerase. Frondanol inhibited 5-lipoxygenase activity, further contributing to its anticancer effects. Conclusions: In conclusion, Frondanol inhibits CRC cell proliferation and induces apoptosis through the mitochondrial pathway in vitro, suggesting that it is a potential nutraceutical for the prevention of human colorectal cancer or a valuable source of anticancer compounds. Full article

Tyrosine kinase inhibitors (TKIs), such as sunitinib and sorafenib, are standard treatments for renal cell carcinoma (RCC). However, most patients treated with these drugs eventually develop drug resistance and relapse; therefore, new treatment options for RCC are urgently required. Recent studies have focused on combination therapies targeting distinct molecular pathways that may produce synergistic effects and help overcome drug resistance in RCC. Niclosamide, an anthelmintic agent, is effective against various cancers; however, its potential in combination with sunitinib for treating RCC has not been evaluated. In this study, we assessed the therapeutic efficacy of niclosamide in combination with sunitinib against RCC and explored the underlying molecular mechanisms. Niclosamide alone inhibited RCC cell proliferation, whereas its combination with sunitinib produced a synergistic anticancer effect, both in vitro and in vivo. RNA sequencing (RNA-seq) and bioinformatic analyses showed that niclosamide modulated critical pathways, including BRIP1- and FANCA-mediated DNA repair and E2F2-regulated cell cycle progression. These findings provide proof-of-concept that niclosamide enhances TKI efficacy through modulation of DNA repair and cell cycle pathways, supporting the rationale for DNA damage response (DDR)-targeted combination strategies in RCC. Full article

Retinal ischemia is a key factor in the progression of vision-threatening ocular diseases, including central retinal artery/vein occlusion, exudative age-related macular degeneration (eAMD), and proliferative diabetic retinopathy. This study investigates the effects of paeoniflorin along with its related neuroprotective molecular pathways in the treatment of retinal ischemia. Free radical or ischemic-like damage was induced by incubating retinal pigment epithelium (RPE) cells for 24 h with 1 mM hydrogen peroxide (H₂O₂) or by subjecting retinal neuronal cells to 8 h of oxygen–glucose deprivation (OGD). Both treatments caused significant cell loss. Treatment with paeoniflorin significantly increased cell viability at 0.5 mM in both cell types. In a Wistar rat model of retinal ischemia and reperfusion (I/R) elicited by sustained high intraocular pressure (HIOP), pre-treatment with 0.5 mM paeoniflorin mitigated the ischemia-induced decline in ERG b-wave amplitude, reduction in whole and inner retinal thickness, loss of fluorogold-labeled retinal ganglion cells, and formation of apoptotic cells. Meanwhile, paeoniflorin effectively downregulated pro-neovascular mediators β-catenin, hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), and the pro-inflammatory/angiogenic biomarker angiopoietin-2 (Ang-2), producing effects similar to the Wnt/β-catenin inhibitor (dickkopf-related protein 1), anti-angiogenic pigment epithelium-derived factor (PEDF), and anti-VEGF Avastin (bevacizumab). These findings suggest that paeoniflorin may protect against retinal ischemia through its anti-inflammatory, anti-neovascular/angiogenic, antioxidative, and neuroprotective properties. Full article

Cardiac muscle has limited proliferative potential; therefore, loss of cardiomyocytes is irreversible and can cause or exacerbate heart failure. Although both pharmacological and non-pharmacological therapies are available, these interventions act primarily on surviving myocardium to manage symptoms and reduce—rather than reverse—adverse remodeling. The only curative option for end-stage heart failure remains heart transplantation; however, its clinical use is severely constrained by the shortage of donor organs. Consequently, regenerative therapies have gained increasing attention as potential novel treatments. Among these, cardiomyocytes derived from patient-specific pluripotent stem cells (PSCs) represent a particularly promising experimental platform for cardiac regeneration. To evaluate the potential of PSCs for cardiac repair through both in vivo and in vitro approaches, we (1) examined the hallmarks of cardiomyocyte maturation and the regulatory systems that coordinate these processes, (2) reviewed recent advances in maturation protocols and derivation techniques, (3) discussed how the cellular microenvironment enhances maturation and function, and (4) identified current barriers to clinical translation. Importantly, we integrated developmental biology with protocol design to provide a mechanistic foundation for PSC-based regeneration. Specifically, insights from cardiac development—such as signaling pathways governing proliferation, alignment, and excitation-contraction coupling—were explicitly linked to the refinement of PSC differentiation and maturation protocols. This developmental perspective allows us to bridge pathology and stem-cell methodology, explaining how disruptions in native cardiac maturation can inform strategies to produce functionally mature PSC-derived cardiomyocytes. Finally, we assessed the clinical prospects of PSC-derived cardiomyocytes, highlighting both the most recent advances and the persistent translational challenges that must be addressed before widespread therapeutic use. Full article

Objective: Previous reports showed that periodontopathic bacteria induce epithelial–mesenchymal transition (EMT) in oral squamous cell carcinoma (OSCC). Fisetin, a foodborne flavonoid, is reportedly associated with anticancer potential in various carcinogenic processes. This study aimed to elucidate the effects of fisetin on Fusobacterium nucleatum- and Porphyromonas gingivalis-induced EMT in OSCC cells. Methods: OSCC cells were co-cultured with live and heat-killed forms of F. nucleatum and P. gingivalis. The concentration of fisetin was set at 10 μM. Morphological changes in the OSCC cells were observed under a light microscope. Cell viability was measured using the Cell Counting Kit-8 assay, whereas migration was examined via wound healing. The mRNA expression of EMT-related markers was quantified using quantitative real-time polymerase chain reaction (PCR), and the expression of EMT-related markers and Wnt pathway-associated proteins was examined via Western blotting. Results: At a multiplicity of infection (MOI) of 300:1 for F. nucleatum and 100:1 for P. gingivalis, OSCC cell viability remained unchanged; however, wound closure rates increased significantly relative to the control. Likewise, treatment with fisetin (10 µM) did not materially alter viability; nevertheless, it attenuated promigratory effects induced by heat-killed periodontal pathogens at 3 h and 6 h. The OSCC cells exhibited EMT-like morphological changes after 6 h of co-culture with heat-killed pathogens. Consistently, reverse-transcriptase quantitative PCR and Western blot analyses showed increased expression of TWIST, ZEB1, and N-cadherin, accompanied by decreased E-cadherin expression, which was more pronounced in F. nucleatum than in P. gingivalis. However, fisetin reversed these trends. Moreover, co-culture with heat-killed pathogens markedly elevated β-catenin protein levels. In line with modulation of canonical Wnt/β-catenin signaling, fisetin and a Wnt inhibitor reduced β-catenin expression, whereas co-treatment with a Wnt agonist restored β-catenin levels in the presence of fisetin. Conclusions: Heat-killed F. nucleatum and P. gingivalis induced EMT in OSCC cells, with F. nucleatum exerting the strongest effect. Fisetin suppressed pathogen-driven EMT, at least partly via canonical Wnt/β-catenin signaling, highlighting its potential therapeutic value and warranting further investigation. Full article