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Cellular stresses trigger autophagy to remove damaged macromolecules and organelles. Lysosomes ‘host’ multiple stress-sensing mechanisms that trigger the coordinated biogenesis of autophagosomes and lysosomes. For example, transcription factor (TF)EB, which regulates autophagy and lysosome biogenesis, is activated following the inhibition of mTOR, a lysosome-localized nutrient sensor. Here we show that reactive oxygen species (ROS) activate TFEB via a lysosomal Ca 2+ -dependent mechanism independent of mTOR. Exogenous oxidants or increasing mitochondrial ROS levels directly and specifically activate lysosomal TRPML1 channels, inducing lysosomal Ca 2+ release. This activation triggers calcineurin-dependent TFEB-nuclear translocation, autophagy induction and lysosome biogenesis. When TRPML1 is genetically inactivated or pharmacologically inhibited, clearance of damaged mitochondria and removal of excess ROS are blocked. Furthermore, TRPML1’s ROS sensitivity is specifically required for lysosome adaptation to mitochondrial damage. Hence, TRPML1 is a ROS sensor localized on the lysosomal membrane that orchestrates an autophagy-dependent negative-feedback programme to mitigate oxidative stress in the cell. Reactive oxygen species (ROS) damage cell components, necessitating their clearance through autophagy. Here, the authors show that ROS can induce autophagy by triggering TRPML1 to release Ca 2+ from the lysosomal lumen, in turn activating the autophagy and lysosomal biogenesis regulator TFEB.

The expression of pro-inflammatory substances is closely related to various diseases. Genistein (GEN), a soy isoflavone, has been proven to inhibit the production of pro-inflammatory substances in macrophages. This study aimed to determine whether GEN exerts its inhibitory effect on the expression of pro-inflammatory substances by suppressing the release of these substances via attenuating pyroptotic cell lysis. Mice were treated with lipopolysaccharide (LPS) and GEN. J774A.1 cells were treated with LPS, adenosine triphosphate (ATP), and GEN. The expression of pro-inflammatory cytokines and high mobility group box 1 (HMGB1) was measured by qRT-PCR and ELISA. The activation of caspase-1 (CASP1) and cleavage of gasdermin D (GSDMD) were determined by Western blot assay. Lactic dehydrogenase (LDH) assay and CCK8 assay were performed to determine the integrity of the cell membrane and cell viability. The concentration of intracellular potassium (K ) and the production of reactive oxygen species (ROS) were determined by the colorimetric method and flow cytometry, respectively. GEN inhibited the production of IL-1β and HMGB1 in LPS-challenged mice and LPS+ATP-treated mouse macrophages by inhibiting GSDMD-mediated pyroptotic cell lysis. Mechanistically, GEN could prevent the loss of intracellular K and the production of ROS caused by LPS+ATP treatment, thereby inhibiting the activation of CASP1. The pathological significance of the release of HMGB1 could be partially attributed to its ability to induce cell apoptosis. GEN inhibits CASP1/GSDMD-mediated pyroptotic cell lysis and the following release of pro-inflammatory substances by suppressing K loss and ROS production of macrophages.

Significance Lysosomes are the cell’s degradation center. To adapt to different environmental conditions, the cell has evolved a set of delicate mechanisms to rapidly change lysosome function, which is referred to as lysosomal adaptation. Notably, lysosomal adaptation is required for cell survival under low nutrient conditions. In this study, we identified TRPML1, a lysosomal Ca ²⁺-permeant ion channel, as an essential player required for lysosomal adaptation. The activity of TRPML1 is potently (up to 10-fold) and rapidly increased upon nutrient starvation. Furthermore, pharmacological inhibition or genetic deletion of TRPML1 completely abolished the effects of starvation on boosting the degradation capability of lysosomes. Upon nutrient starvation, autophagy digests unwanted cellular components to generate catabolites that are required for housekeeping biosynthesis processes. A complete execution of autophagy demands an enhancement in lysosome function and biogenesis to match the increase in autophagosome formation. Here, we report that mucolipin-1 (also known as TRPML1 or ML1), a Ca ²⁺ channel in the lysosome that regulates many aspects of lysosomal trafficking, plays a central role in this quality-control process. By using Ca ²⁺ imaging and whole-lysosome patch clamping, lysosomal Ca ²⁺ release and ML1 currents were detected within hours of nutrient starvation and were potently up-regulated. In contrast, lysosomal Na ⁺-selective currents were not up-regulated. Inhibition of mammalian target of rapamycin (mTOR) or activation of transcription factor EB (TFEB) mimicked a starvation effect in fed cells. The starvation effect also included an increase in lysosomal proteostasis and enhanced clearance of lysosomal storage, including cholesterol accumulation in Niemann–Pick disease type C (NPC) cells. However, this effect was not observed when ML1 was pharmacologically inhibited or genetically deleted. Furthermore, overexpression of ML1 mimicked the starvation effect. Hence, lysosomal adaptation to environmental cues such as nutrient levels requires mTOR/TFEB-dependent, lysosome-to-nucleus regulation of lysosomal ML1 channels and Ca ²⁺ signaling.

Rapamycin (Rap) and its derivatives, called rapalogs, are being explored in clinical trials targeting cancer and neurodegeneration. The underlying mechanisms of Rap actions, however, are not well understood. Mechanistic target of rapamycin (mTOR), a lysosome-localized protein kinase that acts as a critical regulator of cellular growth, is believed to mediate most Rap actions. Here, we identified mucolipin 1 (transient receptor potential channel mucolipin 1 [TRPML1], also known as MCOLN1), the principle Ca2+ release channel in the lysosome, as another direct target of Rap. Patch-clamping of isolated lysosomal membranes showed that micromolar concentrations of Rap and some rapalogs activated lysosomal TRPML1 directly and specifically. Pharmacological inhibition or genetic inactivation of mTOR failed to mimic the Rap effect. In vitro binding assays revealed that Rap bound directly to purified TRPML1 proteins with a micromolar affinity. In both healthy and disease human fibroblasts, Rap and rapalogs induced autophagic flux via nuclear translocation of transcription factor EB (TFEB). However, such effects were abolished in TRPML1-deficient cells or by TRPML1 inhibitors. Hence, Rap and rapalogs promote autophagy via a TRPML1-dependent mechanism. Given the demonstrated roles of TRPML1 and TFEB in cellular clearance, we propose that lysosomal TRPML1 may contribute a significant portion to the in vivo neuroprotective and anti-aging effects of Rap via an augmentation of autophagy and lysosomal biogenesis.

Trueperella pyogenes ( T. pyogenes ) is an important opportunistic pathogen in animals and can also cause diseases in humans. Previous studies have shown that T. pyogenes infection can upregulate the levels of pro-inflammatory cytokines, such as interleukin-1 beta (IL-1β), in host tissues. However, the underlying mechanisms are not yet fully understood. In the current study, we found that both inactivated T. pyogenes cells (iTP) and pyolysin (PLO, a major virulence factor of T. pyogenes ) can promote the transcription of the IL-1β gene both in vivo and in vitro . iTP-caused upregulation of IL-1β gene transcription is dependent on nuclear factor-kappa B (NF-κB). On the other hand, we determined that PLO, but not iTP, can promote the maturation of IL-1β by activating caspase-1-mediated processing of pro-IL-1β. Further, we confirmed that PLO can induce potassium ion (K + ) efflux in mouse macrophages, thereby activating caspase-1 in a Nod-like receptor protein 3 (NLRP3)-dependent manner. Blocking K + efflux or knocking down the expression of NLRP3 both inhibited caspase-1 activation and pro-IL-1β processing. Taken together, these findings demonstrate that T. pyogenes can promote IL-1β expression at both the transcriptional and post-translational levels in a murine macrophage model. These results significantly enhance our understanding of the pathogenesis of T. pyogenes and the interactions between T. pyogenes and host immune system.

The Epstein–Barr virus (EBV) is a prevalent virus linked to various diseases, including infectious mononucleosis (IM), nasopharyngeal carcinoma, and Hodgkin’s lymphoma. Over the past few decades, EBV diagnostic strategies have evolved significantly—progressing from traditional serological assays and histopathology to more sensitive and specific molecular techniques such as nucleic acid amplification and high-throughput sequencing (HTS). While conventional methods remain valuable for their accessibility and established clinical use, they are often limited by sensitivity, speed, and multiplexing capability. In contrast, emerging technologies, including isothermal amplification, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based diagnostics, multi-omics integration, and AI-assisted analysis, have demonstrated great promise in improving diagnostic accuracy, speed, and applicability in diverse clinical settings, including point-of-care testing (POCT). This review systematically explores the historical development of EBV diagnostic technologies, highlighting key milestones and future trends in precision medicine and global health readiness.

Induced pluripotent stem cell (iPSC) technology, in combination with electrophysiological characterization via multielectrode array (MEA), has facilitated the utilization of iPSC-derived motor neurons (iPSC-MNs) as highly valuable models for underpinning pathogenic mechanisms and developing novel therapeutic interventions for motor neuron diseases (MNDs). However, the challenge of MN adherence to the MEA plate and the heterogeneity presented in iPSC-derived cultures raise concerns about the reproducibility of the findings obtained from these cellular models. We discovered that one novel factor modulating the electrophysiological activity of iPSC-MNs is the extracellular matrix (ECM) used in the coating to support in vitro growth, differentiation and maturation of iPSC-MNs. The current study showed that two coating conditions, namely, Poly-L-ornithine/Matrigel (POM) and Polyethyleneimine (PEI) strongly promoted attachment of iPSC-MNs on MEA culture dishes compared to three other coating conditions, and both facilitated the maturation of iPSC-MNs as characterized by the detection of extensive electrophysiological activities from the MEA plates. POM coating accelerated the maturation of the iPSC-MNs for up to 5 weeks, which suits modeling of neurodevelopmental disorders. However, the application of PEI resulted in more even distribution of the MNs on the culture dish and reduced variability of electrophysiological signals from the iPSC-MNs in 7-week cultures, which permitted the detection of enhanced excitability in iPSC-MNs from patients with amyotrophic lateral sclerosis (ALS). This study provides a comprehensive comparison of five coating conditions and offers POM and PEI as favorable coatings for in vitro modeling of neurodevelopmental and neurodegenerative disorders, respectively.

The quality of cellular products used in biological research can directly impact the ability to obtain accurate results. Epstein–Barr virus (EBV) is a latent virus that spreads extensively worldwide, and cell lines used in experiments may carry EBV and pose an infection risk. The presence of EBV in a single cell line can contaminate other cell lines used in the same laboratory, affecting experimental results. We developed three EBV detection systems: (1) a polymerase chain reaction (PCR)-based detection system, (2) a recombinase polymerase amplification (RPA)-based detection system, and (3) a combined RPA-lateral flow assay (LFA) detection system. The minimum EBV detection limits were 1 × 103 copy numbers for the RPA-based and RPA-LFA systems and 1 × 104 copy numbers for the PCR-based system. Both the PCR and RPA detection systems were applied to 192 cell lines, and the results were consistent with those obtained by the EBV assay methods specified in the pharmaceutical industry standards of the People’s Republic of China. A total of 10 EBV-positive cell lines were identified. The combined RPA-LFA system is simple to operate, allowing for rapid result visualization. This system can be implemented in laboratories and cell banks as part of a daily quality control strategy to ensure cell quality and experimental safety and may represent a potential new technique for the rapid detection of EBV in clinical samples.

Parkinson’s disease (PD) is the second most common neurodegenerative disease, with significant socioeconomic burdens. One of the crucial pathological features of PD is the loss of dopaminergic neurons in the substantia nigra (SN). However, the exact pathogenesis remains unknown. Moreover, therapies to prevent neurodegenerative progress are still being explored. We performed bioinformatics analysis to identify candidate genes and molecular pathogenesis in the SN of patients with PD. We analyzed the expression profiles, GSE49036 and GSE7621, which included 31 SN tissues in PD samples and 17 SN tissues in healthy control samples, and identified 86 common differentially expressed genes (DEGs). Then, GO and KEGG pathway analyses of the identified DEGs were performed to understand the biological processes and significant pathways of PD. Subsequently, a protein-protein interaction network was established, with 15 hub genes and four key modules which were screened in this network. The expression profiles, GSE8397 and GSE42966, were used to verify these hub genes. We demonstrated a decrease in the expression levels of 14 hub genes in the SN tissues of PD samples. Our results indicated that, among the 14 hub genes, DRD2, SLC18A2, and SLC6A3 may participate in the pathogenesis of PD by influencing the function of the dopaminergic synapse. CACNA1E, KCNJ6, and KCNB1 may affect the function of the dopaminergic synapse by regulating ion transmembrane transport. Moreover, we identified eight microRNAs (miRNAs) that can regulate the hub genes and 339 transcription factors (TFs) targeting these hub genes and miRNAs. Subsequently, we established an mTF-miRNA-gene-gTF regulatory network. Together, the identification of DEGs, hub genes, miRNAs, and TFs could provide better insights into the pathogenesis of PD and contribute to the diagnosis and therapies.

Human cancer cell lines have an essential role in cancer research, but only authentic cell lines should be used as biological models. Authentication testing using short tandem repeat (STR) loci has shown that MGC-803 cells, which were reported to come from gastric adenocarcinoma, are similar to HeLa. In this study, we confirmed that the MGC-803 cell line contains genetic material from HeLa, including genetic sequence from human papilloma virus 18 (HPV18). Additional alleles were present on STR analysis that remained stable after extensive passaging and generation of mono-clones. This behavior is consistent with a hybrid cell line arising from cell–cell fusion. Further genetic analysis revealed that MGC-803 originated from donors with different genetic ancestries, one African (HeLa) and the other Asian. Transcriptomic analysis demonstrated that MGC-803 closely resembles HeLa and another nasopharyngeal–HeLa hybrid cell line CNE-2. Based on these findings, we conclude that MGC-803 is a hybrid cell line derived from HeLa and other cells, the latter derived from a different patient with Asian genetic ancestry.