-
Analytical Chemistry Jun 2024Several reductases, including nitroreductase, are upregulated under hypoxic conditions characterized by an oxygen-deficient microenvironment. Given that hypoxia is a...
Several reductases, including nitroreductase, are upregulated under hypoxic conditions characterized by an oxygen-deficient microenvironment. Given that hypoxia is a prominent feature of solid tumors, our investigation focused on developing a bioconjugative probe designed for staining tissue under hypoxic conditions, particularly activated by nitroreductase. This probe, developed using our trigger-release-bioconjugation system rooted in the -quinone methide chemistry, exhibited selective activation by nitroreductase and fluorophore labeling within mitochondria and endoplasmic reticulum. As a result, it displayed sustained fluorescence that persisted even after washing steps in cells and tissues. We applied this innovative probe to stain mouse kidney tissue in an acute kidney injury model induced by inadequate oxygen supply. Among various organ tissues examined, only kidney tissue showed significantly higher fluorescence in the injury model compared with the control tissue, as revealed by two-photon microscopic imaging. This research presents a promising avenue for the development of practical staining agents for image-guided tumor surgery.
PubMed: 38940602
DOI: 10.1021/acs.analchem.4c01274 -
Frontiers in Bioscience (Landmark... Jun 2024The endoplasmic reticulum (ER) played an important role in the folding, assembly and post-translational modification of proteins. ER homeostasis could be disrupted by... (Review)
Review
The endoplasmic reticulum (ER) played an important role in the folding, assembly and post-translational modification of proteins. ER homeostasis could be disrupted by the accumulation of misfolded proteins, elevated reactive oxygen species (ROS) levels, and abnormal Ca2+ signaling, which was referred to ER stress (ERS). Ferroptosis was a unique programmed cell death model mediated by iron-dependent phospholipid peroxidation and multiple signaling pathways. The changes of mitochondrial structure, the damage of glutathione peroxidase 4 (GPX4) and excess accumulation of iron were the main characteristics of ferroptosis. ROS produced by ferroptosis can interfere with the activity of protein-folding enzymes, leading to the accumulation of large amounts of unfolded proteins, thus causing ERS. On the contrary, the increase of ERS level could promote ferroptosis by the accumulation of iron ion and lipid peroxide, the up-regulation of ferroptosis related genes. At present, the studies on the relationship between ferroptosis and ERS were one-sided and lack of in-depth studies on the interaction mechanism. This review aimed to explore the molecular mechanism of cross-talk between ferroptosis and ERS, and provide new strategies and targets for the treatment of liver diseases.
Topics: Ferroptosis; Humans; Endoplasmic Reticulum Stress; Liver Diseases; Reactive Oxygen Species; Animals; Signal Transduction; Iron; Lipid Peroxidation; Endoplasmic Reticulum
PubMed: 38940044
DOI: 10.31083/j.fbl2906221 -
Frontiers in Bioscience (Landmark... Jun 2024This study investigated the mechanism by which tazarotene-induced gene 1 (TIG1) inhibits melanoma cell growth. The main focus was to analyze downstream genes regulated...
BACKGROUND
This study investigated the mechanism by which tazarotene-induced gene 1 (TIG1) inhibits melanoma cell growth. The main focus was to analyze downstream genes regulated by TIG1 in melanoma cells and its impact on cell growth.
METHODS
The effects of TIG1 expression on cell viability and death were assessed using water-soluble tetrazolium 1 (WST-1) mitochondrial staining and lactate dehydrogenase release assays. RNA sequencing and Western blot analysis were employed to investigate the genes regulated by TIG1 in melanoma cells. Additionally, the correlation between expression and its downstream genes was analyzed in a melanoma tissue array.
RESULTS
TIG1 expression in melanoma cells was associated with decreased cell viability and increased cell death. RNA-sequencing (RNA-seq), quantitative reverse transcription PCR (reverse RT-QPCR), and immunoblots revealed that TIG1 expression induced the expression of Endoplasmic Reticulum (ER) stress response-related genes such as Homocysteine-responsive endoplasmic reticulum-resident ubiquitin-like domain member 1 (HERPUD1), Binding immunoglobulin protein (BIP), and DNA damage-inducible transcript 3 (DDIT3). Furthermore, analysis of the melanoma tissue array revealed a positive correlation between expression and the expression of , , and . Additionally, attenuation of the ER stress response in melanoma cells weakened the impact of TIG1 on cell growth.
CONCLUSIONS
TIG1 expression effectively hinders the growth of melanoma cells. TIG1 induces the upregulation of ER stress response-related genes, leading to an increase in caspase-3 activity and subsequent cell death. These findings suggest that the ability of retinoic acid to prevent melanoma formation may be associated with the anticancer effect of TIG1.
Topics: Humans; Endoplasmic Reticulum Stress; Melanoma; Cell Line, Tumor; Cell Survival; Gene Expression Regulation, Neoplastic; Cell Death; Apoptosis; Cell Proliferation; Membrane Proteins
PubMed: 38940043
DOI: 10.31083/j.fbl2906233 -
Frontiers in Pharmacology 2024Mitochondria-associated endoplasmic reticulum membranes (MAMs) act as physical membrane contact sites facilitating material exchange and signal transmission between... (Review)
Review
Mitochondria-associated endoplasmic reticulum membranes (MAMs) act as physical membrane contact sites facilitating material exchange and signal transmission between mitochondria and endoplasmic reticulum (ER), thereby regulating processes such as Calipid transport, mitochondrial dynamics, autophagy, ER stress, inflammation, and apoptosis, among other pathological mechanisms. Emerging evidence underscores the pivotal role of MAMs in cardiovascular diseases (CVDs), particularly in aging-related pathologies. Aging significantly influences the structure and function of the heart and the arterial system, possibly due to the accumulation of reactive oxygen species (ROS) resulting from reduced antioxidant capacity and the age-related decline in organelle function, including mitochondria. Therefore, this paper begins by describing the composition, structure, and function of MAMs, followed by an exploration of the degenerative changes in MAMs and the cardiovascular system during aging. Subsequently, it discusses the regulatory pathways and approaches targeting MAMs in aging-related CVDs, to provide novel treatment strategies for managing CVDs in aging populations.
PubMed: 38939842
DOI: 10.3389/fphar.2024.1389202 -
Research (Washington, D.C.) 2024Hepatocellular carcinoma (HCC) was characterized as being hypervascular. In the present study, we generated a single-cell spatial transcriptomic landscape of the...
Hepatocellular carcinoma (HCC) was characterized as being hypervascular. In the present study, we generated a single-cell spatial transcriptomic landscape of the vasculogenic etiology of HCC and illustrated overexpressed Golgi phosphoprotein 73 (GP73) HCC cells exerting cellular communication with vascular endothelial cells with high pro-angiogenesis potential via multiple receptor-ligand interactions in the process of tumor vascular development. Specifically, we uncovered an interactive GP73-mediated regulatory network coordinated with c-Myc, lactate, Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway, and endoplasmic reticulum stress (ERS) signals in HCC cells and elucidated its pro-angiogenic roles in vitro and in vivo. Mechanistically, we found that GP73, the pivotal hub gene, was activated by histone lactylation and c-Myc, which stimulated the phosphorylation of downstream STAT3 by directly binding STAT3 and simultaneously enhancing glucose-regulated protein 78 (GRP78)-induced ERS. STAT3 potentiates GP73-mediated pro-angiogenic functions. Clinically, serum GP73 levels were positively correlated with HCC response to anti-angiogenic regimens and were essential for a prognostic nomogram showing good predictive performance for determining 6-month and 1-year survival in patients with HCC treated with anti-angiogenic therapy. Taken together, the aforementioned data characterized the pro-angiogenic roles and mechanisms of a GP73-mediated network and proved that GP73 is a crucial tumor angiogenesis niche gene with favorable anti-angiogenic potential in the treatment of HCC.
PubMed: 38939041
DOI: 10.34133/research.0387 -
Frontiers in Physiology 2024The mechanisms underlying the occurrence and development of atherosclerosis (AS) are diverse, among which endoplasmic reticulum stress (ERS) is an important mechanism... (Review)
Review
The mechanisms underlying the occurrence and development of atherosclerosis (AS) are diverse, among which endoplasmic reticulum stress (ERS) is an important mechanism that should not be overlooked. However, up to now, there has been no bibliometric study on the relationship between ERS and AS. To understand the research progress in ERS and AS, this paper conducted a statistical analysis of publications in this field using bibliometrics. A total of 1,035 records were retrieved from the Web of Science Core Collection. CiteSpace, VOSviewer, and the R package "bibliometric" were used to analyze the spatiotemporal distribution, countries, authors, institutions, journals, references, and keywords of the literature, and to present the basic information of this field through visualized maps, as well as determine the collaboration relationships among researchers in this field. This field has gradually developed and stabilized over the past 20 years. The current research hotspots in this field mainly include the relationship between ERS and AS-related cells, the mechanisms by which ERS promotes AS, related diseases, and associated cytokines, etc. Vascular calcification, endothelial dysfunction, NLRP3 inflammasome, and heart failure represent the frontier research in this field and are becoming new research hotspots. It is hoped that this study will provide new insights for research and clinical work in the field of ERS and AS.
PubMed: 38938744
DOI: 10.3389/fphys.2024.1392454 -
Journal of Biomedical Science Jun 2024The endoplasmic reticulum (ER) employs stringent quality control mechanisms to ensure the integrity of protein folding, allowing only properly folded, processed and... (Review)
Review
The endoplasmic reticulum (ER) employs stringent quality control mechanisms to ensure the integrity of protein folding, allowing only properly folded, processed and assembled proteins to exit the ER and reach their functional destinations. Mutant proteins unable to attain their correct tertiary conformation or form complexes with their partners are retained in the ER and subsequently degraded through ER-associated protein degradation (ERAD) and associated mechanisms. ER retention contributes to a spectrum of monogenic diseases with diverse modes of inheritance and molecular mechanisms. In autosomal dominant diseases, when mutant proteins get retained in the ER, they can interact with their wild-type counterparts. This interaction may lead to the formation of mixed dimers or aberrant complexes, disrupting their normal trafficking and function in a dominant-negative manner. The combination of ER retention and dominant-negative effects has been frequently documented to cause a significant loss of functional proteins, thereby exacerbating disease severity. This review aims to examine existing literature and provide insights into the impact of dominant-negative effects exerted by mutant proteins retained in the ER in a range of autosomal dominant diseases including skeletal and connective tissue disorders, vascular disorders, neurological disorders, eye disorders and serpinopathies. Most crucially, we aim to emphasize the importance of this area of research, offering substantial potential for understanding the factors influencing phenotypic variability associated with genetic variants. Furthermore, we highlight current and prospective therapeutic approaches targeted at ameliorating the effects of mutations exhibiting dominant-negative effects. These approaches encompass experimental studies exploring treatments and their translation into clinical practice.
Topics: Humans; Endoplasmic Reticulum; Genes, Dominant; Endoplasmic Reticulum-Associated Degradation; Protein Folding; Mutation
PubMed: 38937821
DOI: 10.1186/s12929-024-01054-1 -
Toxicology Mechanisms and Methods Jun 2024Cyclosporine A (CsA) has shown efficacy against immunity-related diseases despite its toxicity in various organs, including the liver, emphasizing the need to elucidate...
Cyclosporine A (CsA) has shown efficacy against immunity-related diseases despite its toxicity in various organs, including the liver, emphasizing the need to elucidate its underlying hepatotoxicity mechanism. This study aimed to capture the alterations in genome-wide expression over time and the subsequent perturbations of corresponding pathways across species. Six data from humans, mice, and rats, including animal liver tissue, human liver microtissues, and two liver cell lines exposed to CsA toxic dose, were used. The microtissue exposed to CsA for 10 d was analyzed to obtain dynamically differentially expressed genes (DEGs). Single-time points data at 1, 3, 5, 7, and 28 d of different species were used to provide additional evidence. Using liver microtissue-based longitudinal design, DEGs that were consistently up- or down-regulated over time were captured, and the well-known mechanism involved in CsA toxicity was elucidated. Thirty DEGs that consistently changed in longitudinal data were also altered in 28-d rat in-house data with concordant expression. Some genes (e.g. , , ) showed good concordance with identified DEGs in 1-d and 7-d mouse data. Pathway analysis revealed up-regulations of protein processing, asparagine N-linked glycosylation, and cargo concentration in the endoplasmic reticulum. Furthermore, the down-regulations of pathways related to biological oxidations and metabolite and lipid metabolism were elucidated. These pathways were also enriched in single-time-point data and conserved across species, implying their biological significance and generalizability. Overall, the human organoids-based longitudinal design coupled with cross-species validation provides temporal molecular change tracking, aiding mechanistic elucidation and biologically relevant biomarker discovery.
PubMed: 38937256
DOI: 10.1080/15376516.2024.2371894 -
The Journal of Neuroscience : the... Jun 2024Many neurons including vasopressin (VP) magnocellular neurosecretory cells (MNCs) of the hypothalamic supraoptic nucleus (SON) generate afterhyperpolarizations (AHPs)...
Many neurons including vasopressin (VP) magnocellular neurosecretory cells (MNCs) of the hypothalamic supraoptic nucleus (SON) generate afterhyperpolarizations (AHPs) during spiking to slow firing, a phenomenon known as spike frequency adaptation. The AHP is underlain by Ca-activated K currents, and while slow component (sAHP) features are well described, its mechanism remains poorly understood. Previous work demonstrated that Ca influx through N-type Ca channels is the primary source of sAHP activation in SON oxytocin neurons, but no obvious channel coupling was described for VP neurons. Given this, we tested the possibility of an intracellular source of sAHP activation, namely the Ca-handling organelles endoplasmic reticulum (ER) and mitochondria in male and female wistar rats. We demonstrate that ER Ca depletion greatly inhibits sAHPs without a corresponding decrease in Ca signal. Caffeine sensitized AHP activation by Ca In contrast to ER, disabling mitochondria with CCCP or blocking mitochondria Ca uniporter (MCU) enhanced sAHP amplitude and duration, implicating mitochondria as a vital buffer for sAHP-activating Ca Block of mitochondria Na-dependent Ca release triphenylphosphonium (TPP) failed to affect sAHPs, indicating that mitochondria Ca doesn't contribute to sAHP activation. Together, our results support that ER Ca-induced Ca release activates sAHPs and mitochondria shape the spatiotemporal trajectory of the sAHP Ca buffering in VP neurons. Overall, this implicates organelle Ca, and specifically ER-mitochondria associated membrane contacts, as an important site of Ca microdomain activity that regulates sAHP signaling pathways. Thus, this site plays a major role in influencing VP firing activity and systemic hormonal release. The slow afterhyperpolarization (sAHP) is mediated by a Ca-dependent K current. Despite its critical role in regulating neuronal spiking, the Ca-dependent mechanisms leading to its activation and spatiotemporal shape remains poorly understood. Here we show that in vasopressin (VP) neurons, dynamic interactions in Ca handling between endoplasmic reticulum (ER) and mitochondria play a significant role in sAHP initiation ( ER Ca release) and its spatiotemporal waveform ( mitochondrial Ca uptake). Our results suggest that contact sites between ER and mitochondria represent Ca microdomains critically involved in initiating the first steps of sAHP generation in VP neurons. Given that changes in the sAHP have been linked to abnormal firing activity in various diseases, our results have both wide-range physiological and pathological implications.
PubMed: 38937101
DOI: 10.1523/JNEUROSCI.0003-24.2024 -
The Science of the Total Environment Jun 2024Crystalline silica (CS) particles are ubiquitously present in the environment, particularly in occupational settings, and exposure to respirable CS causes silicosis,...
Crystalline silica (CS) particles are ubiquitously present in the environment, particularly in occupational settings, and exposure to respirable CS causes silicosis, imposing a significant disease burden. However, the pathogenesis of silicosis remains unclear. Exposure to external stimuli, such as CS, leads to the accumulation of unfolded proteins and triggers endoplasmic reticulum (ER) stress, disrupting tissue immune homeostasis and accelerating pathological progression. While pulmonary macrophages phagocytose CS particles to initiate the immune response, the role of ER stress in this process is unknown. Herein, we used a murine model of silicosis to simulate the pathological progression from acute inflammation to fibrosis in silicosis and conducted in vivo pharmacological inhibition of ER stress to explore the underlying mechanism. Using flow cytometry, we further classified pulmonary macrophages into monocyte-like macrophages (monocytes), interstitial macrophages (IMs), and alveolar macrophages (AMs). Our results showed that CS-induced ER stress primarily contributed to the augmentation of IMs and thereby exerted a significant impact on pulmonary macrophages. Despite coexpressing M1- and M2-like markers, IMs predominantly exhibited an M1-like polarization state and played a proinflammatory role by expressing the cytokines pro-IL-1β and TNF-α during the pathological progression of silicosis. Additionally, IMs recruited by CS-induced ER stress also exhibited high expression of MHCII and exerted active immunomodulatory effects. Overall, our study demonstrates that ER stress induced by CS particles triggers a proinflammatory immune microenvironment dominated by IMs and reveals novel insights into the pulmonary toxicological effects of CS particles.
PubMed: 38936737
DOI: 10.1016/j.scitotenv.2024.174299