Search Results (277)

The enzyme γ-glutamyl transpeptidase (GGT), located on the surface of cellular membranes, hydrolyzes extracellular glutathione (GSH) to guarantee the recycling of cysteine and maintain intracellular redox homeostasis. High expression levels of GGT on tumor cells are associated with increased cell proliferation and resistance against chemotherapy. Therefore, GGT inhibitors have potential as adjuvants in treating GGT-positive tumors; however, most have been abandoned during clinical trials due to toxicity. Recent studies indicate marine-derived ovothiols as more potent non-competitive GGT inhibitors, inducing a mixed cell-death phenotype of apoptosis and autophagy in GGT-overexpressing cell lines, such as the chronic B leukemic cell HG-3, while displaying no toxicity towards non-proliferative cells. In this work, we characterize the activity of two synthetic ovothiol analogs, L-5-sulfanylhistidine and iso-ovothiol A, in GGT-positive cells, such as HG-3 and HL-60 cells derived from acute promyelocytic leukemia. The two compounds inhibit the activity of membrane-bound GGT, without altering cell vitality nor inducing cytotoxic autophagy in HG-3 cells. We provide evidence that a portion of L-5-sulfanylhistidine enters HG-3 cells and acts as a redox regulator, contributing to the increase in intracellular GSH. On the other hand, ovothiol A, which is mostly sequestered by external membrane-bound GGT, induces intracellular ROS increase and the consequent autophagic pathways. These findings provide the basis for developing ovothiol derivatives as adjuvants in treating GGT-positive tumors’ chemoresistance. Full article

Background and Objectives: Colorectal cancer (CRC) is one of the most frequently diagnosed malignancies worldwide. Although chemotherapy is an effective treatment for colorectal cancer (CRC), its effectiveness is frequently hindered by the emergence of resistant cancer cells. Studies have demonstrated a linkage between drug resistance and the pregnane X receptor (PXR), which influences the metabolism and the transport of chemotherapeutic agents. Likewise, autophagy is also a well-established mechanism that contributes to chemotherapy resistance, and it is closely tied to tumor progression. This pre-clinical study aims to investigate the role of mtKRAS-dependent autophagy with PXR expression after treatment with Irinotecan in colorectal cancer. Methods: CRC lines were treated with specific inhibitors, such as 3-methyladeninee, hydroxychloroquine PI-103, and irinotecan hydrochloride, and subjected to various assays, including MTT for cell viability, Western blot for protein expression, siRNA-mediated PXR knock-out, and confocal microscopy for autophagic vacuole visualization. Protein quantification, gene knockdown, and subcellular localization studies were performed under standardized conditions to investigate treatment effects on autophagy and apoptosis pathways. Conclusions: Our experiments showed that PXR knockdown does not alter autophagy levels following Irinotecan treatment, but it promotes apoptotic cell death despite elevated autophagy. Moreover, late-stage autophagy inhibition reduces PXR expression, whereas induction through PI3K/AKT/mTOR inhibition leads to increased expression of PXR. Our experiments uncover a mechanism by which autophagy facilitates the nuclear translocation of the PXR, thereby promoting resistance to Irinotecan across multiple cell lines. Full article

Organ functions generally decline with age, but the ovary is a prototypical organ that undergoes functional loss over time. Autophagy plays a crucial role in maintaining organ homeostasis, and age-related upregulation of the autophagy inhibitor protein, Rubicon, has been linked to cellular and tissue dysfunction. This review describes how granulosa cell autophagy supports follicular growth and oocyte selection and maturation by regulating cellular energy metabolism and protein quality control. We then introduce the role of selective autophagy, including mitophagy or lipophagy, in steroidogenesis and cellular remodeling during luteinization. In aged ovaries, Rubicon accumulation suppresses autophagic flux, leading to diminished oxidative-stress resilience and enhanced DNA damage. Moreover, impaired autophagy drives the accumulation of ATP citrate lyase, which correlates with poor oocyte quality and reduced ovarian reserve. Following fertilization, oocytes further upregulate autophagy to provide the energy required for blastocyst transition. Conversely, in infertility-related disorders, such as premature ovarian insufficiency, endometriosis, and polycystic ovary syndrome, either deficient or excessive autophagy contributes to disease pathogenesis. Both autophagy inhibitors (e.g., Rubicon) and activators (e.g., Beclin1) could be emerging as promising biomarkers for assessing ovarian autophagy status. Therapeutically, Rubicon inhibition by trehalose in aged ovaries and autophagy suppression by agents such as hydroxychloroquine in polycystic ovary syndrome and endometriosis hold potential. Establishing robust methods to evaluate ovarian autophagy will be essential for translating these insights into targeted treatments. Full article

HMG-CoA reductase inhibitors, statins, are extensively used to treat hyperlipidemia, coronary artery disease, and other atherosclerotic disorders. However, one of the common side effects of statin therapy is a mild elevation in liver aminotransferases, observed in less than 3% of patients. Atorvastatin and simvastatin, in particular, are most frequently associated with statin-induced liver injury, leading to treatment discontinuation. Recent research has highlighted the antioxidant and anti-inflammatory properties of glucagon-like peptide-1 receptor (GLP-1R) activation in protecting against liver injury. Nonetheless, the potential protective effects of liraglutide (LIRA), a GLP-1R agonist, against atorvastatin (ATO)-induced liver dysfunction have not been fully elucidated. In this context, the present study aimed to investigate the protective role of LIRA in mitigating ATO-induced liver injury in rats, offering new insights into managing statin-associated hepatotoxicity. Indeed, LIRA treatment improved liver function enzymes and attenuated histopathological alterations. LIRA treatment enhanced antioxidant defenses by increasing Nrf2 content and superoxide dismutase (SOD) activity, while reducing NADPH oxidase. Additionally, LIRA suppressed inflammation by downregulating the HMGB1/TLR-4/RAGE axis and inhibiting the protein expression of pY323-MAPK p38 and pS635-NFκB p65 content resulting in decreased proinflammatory cytokines (TNF-α and IL-1β). Furthermore, LIRA upregulated GLP-1R gene expression and promoted autophagic influx via the activation of the pS473-Akt/pS486-AMPK/pS758-ULK1/Beclin-1 signaling cascade, along with inhibiting apoptosis by reducing caspase-3 content. In conclusion, LIRA attenuated ATO-induced oxidative stress and inflammation via activation of the Nrf-2/SOD cascade and inhibition of the HMGB1/TLR-4/RAGE /MAPK p38/NFκB p65 axis. In parallel, LIRA stimulated autophagy via the AMPK/ULK1/Beclin-1 axis and suppressed apoptosis, thus restoring the balance between autophagy and apoptosis. Full article

Salt stress is one of the most common factors reducing the productivity of crops. We tested the effect of Rapamycin, an mTOR inhibitor and autophagy inducer, for the possible amelioration of high-salinity stress in Eruca sativa. We analyzed the germination rate, the macro- and micro-morphology of seedlings, and the ultrastructure of cotyledons with a Transmission Electron Microscope. The most striking observation was that salt stress blocked the catabolism of the lipid droplets stored in the embryos of E. sativa, also dramatically reducing the starch storage capability in the plastids. As a consequence, lipid droplets remained in the developing seedlings until a late stage. On the contrary, the catabolism of the lipid storage in the embryos in the presence of rapamycin and salt stress was comparable to the control, even if the starch stored in the plastids was lower. Rapamycin-induced autophagic activity was shown by characteristic ultrastructural changes, such as increased membrane recycling. Part of this activity was interpreted as pexophagy, i.e., the autophagy of peroxisomes, where an increase in their turnover rate could be necessary to maintain an active glyoxylate cycle. Full article

Alzheimer’s disease (AD) and schizophrenia are traditionally considered distinct clinical entities, yet growing evidence highlights substantial overlap in their molecular and neuroinflammatory pathogenesis. This review explores current insights into the shared and divergent mechanisms underlying these disorders, with emphasis on neuroinflammation, autophagy dysfunction, blood–brain barrier (BBB) disruption, and cognitive impairment. We examine key signaling pathways, particularly spleen tyrosine kinase (SYK), the mechanistic (or mammalian) target of rapamycin (mTOR), and the S100 calcium-binding protein B (S100B)/receptor for advanced glycation end-products (RAGE) axis, that link glial activation, excitatory/inhibitory neurotransmitter imbalances, and impaired proteostasis across both disorders. Specific biomarkers such as S100B, matrix metalloproteinase 9 (MMP9), and soluble RAGE show promise for stratifying disease subtypes and predicting treatment response. Moreover, psychiatric symptoms frequently precede cognitive decline in both AD and schizophrenia, suggesting that mood and behavioral disturbances may serve as early diagnostic indicators. The roles of autophagic failure, cellular senescence, and impaired glymphatic clearance are also explored as contributors to chronic inflammation and neurodegeneration. Current treatments, including cholinesterase inhibitors and antipsychotics, primarily offer symptomatic relief, while emerging therapeutic approaches target upstream molecular drivers, such as mTOR inhibition and RAGE antagonism. Finally, we discuss the future potential of personalized medicine guided by genetic, neuroimaging, and biomarker profiles to optimize diagnosis and treatment strategies in both AD and schizophrenia. A greater understanding of the pathophysiological convergence between these disorders may pave the way for cross-diagnostic interventions and improved clinical outcomes. Full article

The rapid emergence of resistance limits the application of proteasome inhibitors against solid tumors, despite their effectiveness in the treatment of hematological malignancies. Resistant phenotypes are complex and multifaceted, and, thus, the mechanisms involved have not been adequately described. In this study, a Bortezomib-resistant prostate cancer cell line is created by using the PC-3 cell as a prostate carcinoma model of high metastatic potential. The main biochemical differences and adaptations exhibited by the resistant cells revolve around apoptosis evasion, autophagy induction (functioning as a ubiquitin-proteasome system substitute), expression of epithelial-to-mesenchymal transition markers, and increased aggressiveness. Broad-spectrum signaling pathway analyses also reveal an upregulation and activation of Nf-κB, STAT3, cJun, and Elk1 transcription factors in the resistant cells. Additionally, intracellular reactive oxygen species assays reveal a downregulation in resistant cells, which is theorized to be a consequence of metabolic changes, increased autophagic flux, and antioxidative enzyme action. These findings expand our understanding of proteasome inhibitor resistance and highlight key kinases and transcription factors as novel potential therapeutic targets. Effective inhibition of resistance-specific pathways could re-sensitize the cells to proteasome inhibitors, thus surpassing current therapeutic limitations. Full article

Resistance to tyrosine kinase inhibitors (TKIs, e.g., sorafenib and lenvatinib) presents a significant hurdle for hepatocellular carcinoma (HCC) treatment, underscoring the need to decipher the underlying mechanisms for improved therapeutic strategies. MicroRNAs (miRNAs) have emerged as critical modulators in HCC progression and TKI resistance. In this study, we report a positive correlation between the expression levels of a tumor suppressor miRNA, miR-142-3p, and increased sensitivity to sorafenib and lenvatinib, supported by clinical data from the BIOSTORM HCC cohort. Overexpression of miR-142-3p in TKI-resistant HCC cells significantly inhibited proliferation and colony formation, induced apoptosis, increased cell cycle arrest at the G2 phase, and reduced migration and invasion by reversing epithelial–mesenchymal transition. Notably, combining miR-142-3p with lenvatinib synergistically inhibited growth in both inherent and acquired TKI-resistant HCC cells by modulating critical signaling pathways, including STAT3, PI3K/AKT, MAPK, YAP1, and by impeding autophagic influx. RNA-sequencing of a TKI-resistant HCC cell line ± miR-142-3p overexpression identified YES1 and TWF1 as direct downstream target genes of miR-142-3p, both of which are key genes associated with drug resistance in HCC. Small interfering RNA (siRNA)-mediated knockdown of these genes mirrored the antitumor effects of miR-142-3p and enhanced TKI sensitivity, with YES1 knockdown decreasing YAP1 phosphorylation, and TWF1 knockdown inhibiting autophagy. Collectively, these findings indicate that restoring miR-142-3p expression or targeting its downstream effectors YES1 and TWF1 offers a promising strategy to overcome drug resistance and improve therapeutic outcome in HCC. Full article

Lysosomal dysfunction has emerged as a central contributor to the pathogenesis of cardiovascular diseases (CVDs), particularly due to its involvement in chronic inflammation, lipid dysregulation, and oxidative stress. This review highlights the multifaceted roles of lysosomes in CVD pathophysiology, focusing on key mechanisms such as NLRP3 inflammasome activation, TFEB-mediated autophagy regulation, ferroptosis, and the role of apolipoprotein M (ApoM) in preserving lysosomal integrity. Additionally, we discuss how impaired lysosomal acidification, mediated by V-ATPase, contributes to lipid-induced cardiac dysfunction. Therapeutically, several pharmacological agents, such as statins, SGLT2 inhibitors, TRPML1 agonists, resveratrol, curcumin, and ferroptosis modulators (e.g., GLS1 activators and icariin), have demonstrated promise in restoring lysosomal function, enhancing autophagic flux, and reducing inflammatory and oxidative injury in both experimental models and early clinical settings. However, key challenges remain, including limitations in drug delivery systems, the absence of lysosome-specific biomarkers, and insufficient clinical validation of these strategies. Future research should prioritize the development of reliable diagnostic tools for lysosomal dysfunction, the optimization of targeted drug delivery, and large-scale clinical trials to validate therapeutic efficacy. Incorporating lysosome-modulating approaches into standard cardiovascular care may offer a new precision medicine paradigm for managing CVD progression. Full article

The dysregulation of the Hippo signaling pathway leads to the aberrant activation of oncogenic YAP and TAZ, driving tumor progression. In breast cancer, this disruption promotes proliferation and metastasis. This study investigates the effects of CA3, a selective YAP inhibitor, on the proteome of triple-negative breast cancer MDA-MB-231 and luminal-A-like MCF7 cells. Proteomic changes were analyzed via nano-LC-MS/MS, while cytotoxicity, apoptosis, and autophagy were assessed through WST-1 assays, flow cytometry, and Western blot analyses. Bioinformatics tools were employed to identify enriched pathways. MDA-MB-231 cells exhibited an increased expression of DNA repair proteins (p < 0.05), indicating a compensatory response to maintain genomic stability. In contrast, MCF7 cells showed a downregulation of DNA repair factors (p < 0.005). Additionally, metabolic reprogramming was apparent in MCF7 cells (p < 0.001). Apoptosis assays revealed a rise in cell death, while cell cycle analysis indicated pronounced G1-phase arrest in MDA-MB-231 cells (p < 0.01). Moreover, autophagic suppression was particularly evident in MCF7 cells. This study, for the first time, provides evidence that breast cancer subtypes exhibit distinct dependencies on YAP-driven pathways, revealing potential therapeutic vulnerabilities. Targeting Hippo signaling alongside DNA repair in triple-negative breast cancer or combining YAP inhibition with metabolic blockade in luminal breast cancer holds significant potential to enhance treatment efficacy. Full article

Age-related hearing loss (ARHL) is a highly prevalent, burdensome sensorineural hearing loss closely associated with impaired autophagic influx. Our previous studies revealed that neuritin, a neurotrophic factor primarily expressed in the central nervous system, could alleviate drug-induced damages in hair cells (HCs) and spiral ganglion neurons. However, its effects on ARHL and whether these effects are closely related to autophagy remain unclear. Using the Nrn1 knock-in mice and cultured cochlear basilar membrane (CBM) of the neonatal mouse, we show that neuritin could restore aging-associated hearing loss and alleviate senescence-associated damage in the cochlea. Overexpression of neuritin in support cells (SCs) alleviates the loss of cochlear HCs and nerve fibers, reducing the damage to spiral ganglion neurons and the shifts in ABR’s high-frequency threshold. Furthermore, conditional overexpression of neuritin in SCs improves autophagic influx by upregulating the expression of microtubule-associated protein 1 light chain 3 type B (LCB3) protein and downregulating the expression of p21 protein. In cultured neonatal mouse CBM, neuritin administration significantly inhibits D-galactose-induced HC loss, cellular apoptosis, and ROS production and promotes autophagic influx. These effects were weakened when the autophagy inhibitor 3-MA was added. In summary, our results confirm the therapeutic potential of neuritin treatment for ARHL. Full article

Sphingomyelin nanoemulsions (SNs) are promising drug delivery systems with potential for treating challenging tumors, including non-small cell lung cancer (NSCLC), which has a poor prognosis and a 5-year survival rate below 5%. Understanding the toxicity mechanisms and intracellular behavior of SNs is crucial for optimizing their therapeutic application. This study aims to investigate the interaction between SNs and A549 lung adenocarcinoma cells, focusing on their cytotoxic effects and mechanisms of cellular toxicity. SNs were synthesized and characterized for size, surface charge, and stability. A549 cells were treated with varying concentrations of SNs, and cellular uptake pathways were assessed using inhibitors of energy-dependent processes. Cytotoxicity was evaluated through an alamarBlue assay to determine the IC₅₀ value after 24 h. Mechanisms of toxicity, including lysosomal and mitochondrial involvement, were examined using co-localization studies, mitochondrial membrane potential assays, and markers of apoptosis. SNs exhibited rapid cellular uptake via energy-dependent pathways. The IC₅₀ concentration for A549 cells was 0.89 ± 0.15 mg/mL, suggesting favorable cytocompatibility compared to other nanocarriers. At IC₅₀, SNs induced apoptosis characterized by lysosomal damage, mitochondrial membrane permeabilization, and the release of apoptotic factors. These effects disrupted autophagic flux and contributed to cell death, demonstrating potential for overcoming drug resistance. Resveratrol-loaded SNs showed enhanced cytotoxicity, supporting their application as targeted drug delivery vehicles. This study highlights the potential of SNs as efficient drug delivery systems for NSCLC therapy, offering insights into their cellular interactions and toxicity mechanisms. These findings pave the way for the rational design of SN-based therapeutic platforms for cancer and other mitochondria-related diseases. Full article

Autophagy is a critical mechanism by which methamphetamine (METH) induces neuronal damage and neurotoxicity. Prolonged METH exposure can result in the accumulation of autophagosomes within cells. The autophagy process encompasses several essential vesicle-related biological steps, collectively referred to as the autophagic flux. However, the precise mechanisms by which METH modulates the autophagic flux and the underlying pathways remain to be elucidated. In this study, we utilized a chronic METH exposure mouse model and cell model to demonstrate that METH treatment leads to an increase in p62 and LC3B-II and the accumulation of autophagosomes in striatal neurons and SH-SY5Y cells. To assess autophagic flux, this study utilized autophagy inhibitors and inducers. The results demonstrated that the lysosomal inhibitor chloroquine exacerbated autophagosome accumulation; however, blocking autophagosome formation with 3-methyladenine did not prevent METH-induced autophagosome accumulation. Compared to the autophagy activator rapamycin, METH significantly reduced autophagosome–lysosome fusion, leading to autophagosome accumulation. Rab7a is a critical regulator of autophagosome–lysosome fusion. Although Rab7a expression was upregulated in SH-SY5Y cells and brain tissues after METH treatment, immunoprecipitation experiments revealed weakened interactions between Rab7a and the lysosomal protein RILP. Overexpression of active Rab7a (Rab7a Q67L) significantly alleviated the METH-induced upregulation of LC3-II and p62. PTEN, a key regulator of Rab7a dephosphorylation, was downregulated following METH treatment, resulting in decreased Rab7a dephosphorylation and reduced Rab7a activity, thereby contributing to autophagosome accumulation. We further investigated the role of neuronal exosomes in the autophagy process. Our results demonstrated that the miRNA expression profiles in exosomes released by METH-induced SH-SY5Y cells were significantly altered, with 122 miRNAs upregulated and 151 miRNAs downregulated. KEGG and GO enrichment analyses of these differentially expressed miRNAs and their target genes revealed significant associations with the autophagy pathway and potential regulation of PTEN expression. Our experiments confirmed that METH-induced exosomes reduced PTEN expression levels and decreased Rab7a dephosphorylation, thereby exacerbating autophagic flux impairment and autophagosome accumulation. In conclusion, our study indicated that METH and its induced neuronal exosomes downregulate PTEN expression, leading to reduced Rab7a dephosphorylation. This, in turn, hinders the fusion of autophagosomes and lysosomes, ultimately resulting in autophagic flux impairment and neuronal damage. Full article

The aging population is steadily increasing, with aging and age-related diseases serving as major risk factors for morbidity, mortality, and economic burden. Peanuts, known as the “longevity nut” in China, have been shown to offer various health benefits, with peanut skin extract (PSE) emerging as a key compound of interest. This study investigates the bioactive compound in PSE with anti-aging potential and explores its underlying mechanisms of action. Procyanidin A1 (PC A1) was isolated from PSE, guided by the K6001 yeast replicative lifespan model. PC A1 prolonged the replicative lifespan of yeast and the yeast-like chronological lifespan of PC12 cells. To further confirm its anti-aging effect, cellular senescence, a hallmark of aging, was assessed. In senescent cells induced by etoposide (Etop), PC A1 alleviated senescence by reducing ROS levels, decreasing the percentage of senescent cells, and restoring proliferative capacity. Transcriptomics analysis revealed that PC A1 induced apoptosis, reduced senescence-associated secretory phenotype (SASP) factors, and modulated the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. The antioxidative capacity of PC A1 was also evaluated, showing enhanced resistance to oxidative stress in PC12 cells by reducing reactive oxygen species (ROS) and malondialdehyde (MDA) levels and increasing superoxide dismutase (SOD) activity. Moreover, PC A1 induced autophagy, as evidenced by an increase in fluorescence-labeled autophagic compartments and confirmation via Western blot analysis of autophagy-related proteins. In addition, the treatment of an autophagy inhibitor abolished the antioxidative stress and senescence-alleviating effects of PC A1. These findings reveal that PC A1 extended lifespans and alleviated cellular senescence by enhancing oxidative stress resistance and inducing autophagy, positioning it as a promising candidate for further exploration as a geroprotective agent. Full article

Cinnamaldehyde (CIN), which is a cosmetic fragrance allergen regulated by the European Union, can induce allergic contact dermatitis in consumers, reducing their quality of life. Autophagy may be associated with the dendritic cell (DC) response to chemical sensitizers. We hypothesized that CIN would activate DCs through autophagy during skin sensitization. In this study, Tohoku Hospital Pediatrics-1 cells (THP-1 cells) were used as an in vitro DC model, and we evaluated the expression of cell activation markers, intracellular oxidative stress, and autophagy pathway-related genes in response to CIN in THP-1 cells. CIN exposure activated THP-1 cells, which presented increases in CD54 and CD86 expression and ROS generation. Transcriptomic analysis revealed that the genes that were differentially expressed after CIN stimulation were mostly associated with autophagy. The autophagy markers LC3B, p62, and ATG5 had upregulated mRNA and protein levels after CIN exposure. Furthermore, the effects of the autophagy inhibitor Baf-A1 and the autophagy activator rapamycin were investigated on CIN-treated cells. Pretreatment with Baf-A1 in THP-1 cells impaired autophagic flux and dramatically promoted cell activation and oxidative stress triggered by CIN. Conversely, rapamycin inhibited cell activation and the ROS content in CIN-challenged cells while increasing autophagy levels via a reduction in mTOR expression. These results suggest that the autophagy pathway has a pivotal influence on the regulation of CIN-induced activation in THP-1 cells, which provides new insight into the pathogenesis and precise therapeutic strategies for ACD. Full article