Endoplasmic reticulum stress and unfolded protein response in cardiovascular diseases

Farnesol Improves Endoplasmic Reticulum Stress and Hepatic Metabolic Dysfunction Induced by Tunicamycin in Mice

Endoplasmic reticulum (ER) stress significantly affects liver metabolism, often leading to disorders such as hepatic steatosis. Tunicamycin (TM), a known ER stress inducer, is frequently used to model metabolic stress, but its specific effects on liver energy homeostasis remain unclear. This study investigates how farnesol (FOH), a natural compound with antioxidant and anti-inflammatory properties, counteracts TM-induced ER stress and its associated metabolic disruptions in the liver. Using both primary hepatocytes and a mouse model, this study demonstrates that TM treatment caused upregulation of ER stress markers, including ATF4, and disrupted genes related to lipid metabolism and gluconeogenesis. Co-treatment with FOH reduced these stress markers and restored the expression of metabolic genes. In vivo, FOH treatment alleviated oxidative stress, reduced lipid accumulation, and restored normal glycogen and lipid metabolism. Histological analysis further confirmed that FOH preserved liver architecture and minimized cellular damage. FOH also stabilized serum lipid profiles and modulated key metabolic biomarkers, suggesting its protective role against TM-induced liver injury. These findings suggest that FOH has therapeutic potential in mitigating ER stress-related metabolic dysfunctions, offering promising insights for the treatment of liver diseases linked to metabolic stress.

Irisin Mitigates Doxorubicin-Induced Cardiotoxicity by Reducing Oxidative Stress and Inflammation via Modulation of the PERK-eIF2α-ATF4 Pathway

Purpose

Doxorubicin (DOX), an anthracycline antibiotic, has limited clinical use due to its pronounced cardiotoxicity. Irisin, a myokine known for its metabolic regulation, has shown therapeutic effects on cardiovascular disease. This study investigates the potential cardioprotective function of irisin in reducing the cardiac injury induced by DOX.

Methods

In vitro, H9c2 cells were pretreated with irisin (20 nM) for 24 hours before exposure to DOX (1 μM). In vivo, C57BL/6 mice were administered DOX (5 mg/kg/week, i.p.) for 4 weeks, reaching a cumulative dose of 20 mg/kg. Irisin (1 mg/kg/ 3 days, i.p.) was administered to the mice both 7 days prior to and during DOX injection.Cardiac function was evaluated by echocardiography, and cardiac histology was assessed using HE, WGA, and Masson staining. Myocardial injury markers were quantified using ELISA, and apoptosis was analyzed via TUNEL staining. Oxidative stress was determined by measuring antioxidase activity, MDA and GSH levels, and DHE staining, while mitochondrial superoxide production was assessed using MitoSOX Red. Mitochondrial morphology and function evaluated using transmission electron microscopy and Seahorse analysis, respectively Inflammatory cytokines were quantified in serum and cell supernatants. The role of the PERK-eIF2α-ATF4 pathway mediated by irisin was investigated by Western blot. Using adeno-associated virus serotype-9 carrying mouse FNDC5 shRNA (AAV9-shFNDC5) further validated the protective role of irisin in DOX-induced myocardial injury.

Results

Irisin reduced DOX-induced cardiac dysfunction and fibrosis. Moreover, irisin mitigated oxidative stress and inflammation through inhibiting the PERK-eIF2α-ATF4 pathway activated by DOX, thus preserving mitochondrial function. While cardiac FNDC5 knockdown exacerbated DOX-induced heart injury and PERK-eIF2α-ATF4 activation, which was partially reversed by irisin.

Conclusion

Irisin mitigates oxidative stress and inflammation by modulating the PERK-eIF2α-ATF4 pathway, highlighting its potential as a prospective approach for combating DOX-induced cardiotoxicity.

Methylglyoxal Formation-Metabolic Routes and Consequences

Methylglyoxal (MGO), a by-product of glycolysis, plays a significant role in cellular metabolism, particularly under stress conditions. However, MGO is a potent glycotoxin, and its accumulation has been linked to the development of several pathological conditions due to oxidative stress, including diabetes mellitus and neurodegenerative diseases. This paper focuses on the biochemical mechanisms by which MGO contributes to oxidative stress, particularly through the formation of advanced glycation end products (AGEs), its interactions with antioxidant systems, and its involvement in chronic diseases like diabetes, neurodegeneration, and cardiovascular disorders. MGO exerts its effects through multiple signaling pathways, including NF-κB, MAPK, and Nrf2, which induce oxidative stress. Additionally, MGO triggers apoptosis primarily via intrinsic and extrinsic pathways, while endoplasmic reticulum (ER) stress is mediated through PERK-eIF2α and IRE1-JNK signaling. Moreover, the activation of inflammatory pathways, particularly through RAGE and NF-κB, plays a crucial role in the pathogenesis of these conditions. This study points out the connection between oxidative and carbonyl stress due to increased MGO formation, and it should be an incentive to search for a marker that could have prognostic significance or could be a targeted therapeutic intervention in various diseases.

Signaling pathways behind the biological effects of tanshinone IIA for the prevention of cancer and cardiovascular diseases

Tanshinone IIA (Tan IIA) is a well-known fat-soluble diterpenoid found in Salvia miltiorrhiza, recognized for its various biological effects. The molecular signaling pathways of Tan IIA have been investigated in different diseases, including the anti-inflammatory, hepatoprotective, renoprotective, neuroprotective effects, and fibrosis prevention. This article provides a brief overview of the signaling pathways related to anti-cancer and cardioprotective effects of Tan IIA. It shows that Tan IIAs anti-cancer ability has good expectation through multiplicity mechanisms affecting various aspects' tumor biology. The major pathways involved in its anti-cancer effects include inhibition of PI3/Akt, MAPK, and p53/p21 signaling which leads to enhancement of immune responses and increased radiation sensitivity. Some essential pathways responsible for cardioprotective effects induced by Tan IIA are PI3/AKT activation, MAPK, and SIRT1 promoting protection against ischemia/reperfusion injury in myocardial cells as well as inhibiting pathological remodeling processes. Finally, the article underscores the complex and specific signaling pathways influenced by Tan IIA. The PI3/Akt and MAPK pathways play critical roles in the anti-cancer and cardioprotective effects of Tan IIA. Particularly, Tan IIA suppresses the proliferation of malignancies in cancerous cells but stimulates protective mechanisms in normal cardiovascular cells. These findings highlight the importance of investigating molecular signaling pathways in evaluating the therapeutic potential of natural products. Studying about signaling pathways is vital in understanding the therapeutic aspects of Tan IIA and its derivatives as anti-cancer and cardio-protective agents. Further research is necessary to understand these complex mechanisms.

Cadmium-Induced Kidney Apoptosis Based on the IRE1α-XBP1 Signaling Pathway and the Protective Effect of Quercetin

Cadmium (Cd) is an important environmental pollutant that can enter the body and inflict kidney damage. Quercetin (Que) is a natural flavonoid compound that can alleviate kidney damage in Cd-treated rats, but the specific mechanism is unclear. Herein, 24 male Sprague-Dawley rats were divided into four groups, namely the control, Cd, Cd + Que, and Que groups. Four weeks later, the rats were anesthetized with ether and were euthanized; then, their blood was collected and their kidneys were removed. Renal function markers were measured. Kidney tissue structure was observed by HE staining, cell apoptosis was detected by the TUNEL method, and mRNA and protein expression levels in the IRE1α-XBP1 apoptosis signaling pathway were analyzed by RT-PCR and Western blotting. Results showed that the Cd treatment group exhibited decreased renal dysfunction and pathologic injury. Cd-induced tissue damage and cell apoptosis and significantly increased the mRNA and protein expression levels (p < 0.01) related to the IRE1α-XBP1 signaling pathway. Compared with the Cd group, the Cd + Que group exhibited increased renal dysfunction. Conversely, kidney tissue damage and renal cell apoptosis decreased, and the mRNA and protein expression levels of IRE1α and XBP1 significantly decreased (p < 0.01). Cd treatment inflicted renal damage. Therefore, Que can restore the kidney tissue damage and alleviate the cell apoptosis caused by Cd through the inhibition of the IRE1α-XBP1 signaling pathway.

Canagliflozin differentially modulates carfilzomib-induced endoplasmic reticulum stress in multiple myeloma and endothelial cells

Carfilzomib (CFZ), a second-generation proteasome inhibitor, is a key treatment for multiple myeloma (MM), but its use is associated with significant cardiovascular adverse events (CVAEs), including heart failure and hypertension. Endothelial dysfunction is believed to contribute to these CVAEs. Building on our previous findings that CFZ induces endothelial toxicity and that canagliflozin protects against CFZ-induced endothelial apoptosis, this study aimed to evaluate CFZ-induced endoplasmic reticulum (ER) stress and autophagy in endothelial and MM cells, as well as the impact of canagliflozin on these processes and its impact on the anticancer effects of CFZ in MM cells. Endothelial cells (HUVECs and EA.hy926) and multiple myeloma cells (RPMI8226) were treated with 0.5 µM CFZ, either alone or in combination with canagliflozin (5-20 µM), to assess the effects on ER stress and autophagy in both cell types. CFZ induced ER stress in endothelial and MM cells. In endothelial cells, canagliflozin mitigated CFZ-induced markers of ER stress, while unexpectedly upregulating CFZ-induced CHOP. Whereas, in MM cells, canagliflozin did not alter CFZ-induced ER stress, but instead further upregulated CFZ-induced ATF-4. In addition, CFZ induced autophagy in endothelial cells while inhibiting it in MM cells. Canagliflozin abrogated CFZ-induced autophagy in endothelial cells. In striking contrast to its effects in endothelial cells, canagliflozin enhanced the cytotoxic effects of CFZ in MM cells. Intriguingly, in an innovative co-culture system, canagliflozin enhanced CFZ-induced apoptosis in MM cells while protecting endothelial cells. These findings underscore the dual role of canagliflozin in reducing CFZ-induced endothelial toxicity, while enhancing its cytotoxic effect in MM.

Organelle-Targeting Nanoparticles

Organelles are specialized subunits within cells which carry out vital functions crucial to cellular survival and form a tightly regulated network. Dysfunctions in any of these organelles are linked to numerous diseases impacting virtually every organ system in the human body. Targeted delivery of therapeutics to specific organelles within the cell holds great promise for overcoming challenging diseases and improving treatment outcomes through the minimization of therapeutic dosage and off-target effects. Nanoparticles are versatile and effective tools for therapeutic delivery to specific organelles. Nanoparticles offer several advantageous characteristics, including a high surface area-to-volume ratio for efficient therapeutic loading and the ability to attach targeting moieties (tethers) that enhance delivery. The choice of nanoparticle shape, size, composition, surface properties, and targeting ligands depends on the desired target organelle and therapeutic effect. Various nanoparticle platforms have been explored for organelle targeting, such as liposomes, polymeric nanoparticles, dendrimers, and inorganic nanoparticles. In this review, current and emerging approaches to nanoparticle design are examined in the context of various diseases linked to organelle dysfunction. Specifically, advances in nanoparticle therapies targeting organelles such as the nucleus, mitochondria, lysosomes/endosomes, Golgi apparatus, and endoplasmic reticulum are comprehensively and critically discussed.

Ceapin-A7 suppresses the protective effects of Octreotide in human and bovine lung endothelial cells

Endothelial injury can be the cause and consequence of severe inflammation and injury. Synthetic somatostatin analogs-which suppress Growth Hormone-are clinically-approved drugs associated with anti-inflammatory activities. In the present study, we suggest that the protective activities of Octreotide in human and bovine endothelial cells are mitigated by Ceapin-A7, which is an activating transcription factor 6 inhibitor. To study endothelial function, we assessed protein expression levels of key cytoskeletal proteins, as well as paracellular permeability. To evaluate inflammation, we measured factors that promote vascular leak, as well as reactive oxygen species generation. Collectively, our study supports the involvement of activating transcription factor 6 in the protective effects of Octreotide in endothelial barrier function.

Key Genes and Biological Pathways in Pulmonary Arterial Hypertension Related to Endoplasmic Reticulum Stress Identified by Bioinformatics

ABSTRACT

Pulmonary arterial hypertension (PAH) is a cardiopulmonary vascular condition with an unclear pathogenesis. Targeting endoplasmic reticulum (ER) stress has been suggested as a novel treatment approach for PAH, but the mechanisms involving ER stress-related genes in PAH are not well understood. Microarray data for PAH and ER stress-related genes were analyzed. Differential and Venn analyses identified 17 differentially expressed ER stress-related genes in PAH. Candidate drugs targeting these genes were predicted using the CMap database. A protein-protein interaction (PPI) network was constructed, and hub genes (LCN2, IGF1, VCAM1, EDN1, HMOX1, TLR4) with complex interplays were identified using the STRING database and Cytoscape plugins. The clinical diagnostic performance of the hub genes was evaluated using ROC curves. The GeneMANIA Web site was utilized to predict enriched pathways associated with the hub genes and their functionally similar genes. MiRNAs and transcription factors targeting the hub genes were predicted using the Networkanalyst Web site. The immune levels in control samples and PAH samples were assessed using various algorithms. Nine drug candidates were found to potentially target the identified ER stress-related genes. The hub genes and their correlated genes were significantly enriched in immune-related pathways. The PAH group showed increased immune cell infiltration, indicating a heightened immune response. This study sheds light on the role of ER stress-associated hub genes in PAH and proposes potential drugs targeting these genes. These findings provide valuable insights into PAH mechanisms and support the exploration of ER stress as a therapeutic target.

TUDCA modulates drug bioavailability to regulate resistance to acute ER stress in Saccharomyces cerevisiae

Cells counter accumulation of misfolded secretory proteins in the endoplasmic reticulum (ER) through activation of the Unfolded Protein Response (UPR). Small molecules termed chemical chaperones can promote protein folding to alleviate ER stress. The bile acid tauroursodeoxycholic acid (TUDCA) has been described as a chemical chaperone. While promising in models of protein folding diseases, TUDCA's mechanism of action remains unclear. Here, we found TUDCA can rescue growth of yeast treated with the ER stressor tunicamycin (Tm), even in the absence of a functional UPR. In contrast, TUDCA failed to rescue growth on other ER stressors. Nor could TUDCA attenuate chronic UPR associated with specific gene deletions or overexpression of a misfolded mutant secretory protein. Neither pretreatment with nor delayed addition of TUDCA conferred protection against Tm. Importantly, attenuation of Tm-induced toxicity required TUDCA's critical micelle forming concentration, suggesting a mechanism where TUDCA directly sequesters drugs. Indeed, in several assays, TUDCA-treated cells closely resembled cells treated with lower doses of Tm. In addition, we found TUDCA can inhibit dyes from labeling intracellular compartments. Thus, our study challenges the model of TUDCA as a chemical chaperone and suggests that TUDCA decreases drug bioavailability, allowing cells to adapt to ER stress.

The role of the ER stress sensor IRE1 in cardiovascular diseases

Despite enormous advances in the treatment of cardiovascular diseases, including I/R injury and heart failure, heart diseases remain a leading cause of mortality worldwide. Inositol-requiring enzyme 1 (IRE1) is an evolutionarily conserved sensor endoplasmic reticulum (ER) transmembrane protein that senses ER stress. It manages ER stress induced by the accumulation of unfolded/misfolded proteins via the unfolded protein response (UPR). However, if the stress still persists, the UPR pathways are activated and induce cell death. Emerging evidence shows that, beyond the UPR, IRE1 participates in the progression of cardiovascular diseases by regulating inflammation levels, immunity, and lipid metabolism. Here, we summarize the recent findings and discuss the potential therapeutic effects of IRE1 in the treatment of cardiovascular diseases.

Inhibition of vascular smooth muscle cell PERK/ATF4 ER stress signaling protects against abdominal aortic aneurysms

Abdominal aortic aneurysms (AAA) are a life-threatening cardiovascular disease for which there is a lack of effective therapy preventing aortic rupture. During AAA formation, pathological vascular remodeling is driven by vascular smooth muscle cell (VSMC) dysfunction and apoptosis, for which the mechanisms regulating loss of VSMCs within the aortic wall remain poorly defined. Using single-cell RNA-Seq of human AAA tissues, we identified increased activation of the endoplasmic reticulum stress response pathway, PERK/eIF2α/ATF4, in aortic VSMCs resulting in upregulation of an apoptotic cellular response. Mechanistically, we reported that aberrant TNF-α activity within the aortic wall induces VSMC ATF4 activation through the PERK endoplasmic reticulum stress response, resulting in progressive apoptosis. In vivo targeted inhibition of the PERK pathway, with VSMC-specific genetic depletion (Eif2ak3fl/fl Myh11-CreERT2) or pharmacological inhibition in the elastase and angiotensin II-induced AAA model preserved VSMC function, decreased elastin fragmentation, attenuated VSMC apoptosis, and markedly reduced AAA expansion. Together, our findings suggest that cell-specific pharmacologic therapy targeting the PERK/eIF2α/ATF4 pathway in VSMCs may be an effective intervention to prevent AAA expansion.

Identification of critical endoplasmic reticulum stress-related genes in advanced atherosclerotic plaque

Atherosclerosis (AS) is the principal pathological cause of atherosclerotic cardiovascular diseases. Chronic endoplasmic reticulum stress (ERS) has been implicated in AS aetiopathogenesis, but the underlying molecular interactions remain unclear. This study aims to identify the molecular mechanisms of ERS in AS pathogenesis to inform innovative diagnostic approaches and therapeutic targets for managing AS. GSE28829 and GSE43292-human early and advanced carotid atherosclerotic tissue samples-were obtained from the Gene Expression Omnibus database. Endoplasmic reticulum stress-related genes (ERSRGs) were obtained from GeneCards. Differential gene expression and weighted gene co-expression network analyses were conducted to identify genes associated with atherosclerosis, and intersection with ER-related genes revealed three ERSRGs (i.e. CTSB, LYN, and CYBB) associated with advanced atherosclerotic plaque. These three ERSRGs exhibited associations with various immune cells. Additionally, the three ERSRGs were upregulated in human atherosclerotic tissues, mouse models of progressive atherosclerotic lesions, and in vitro macrophage models. In conclusion, this study identified CTSB, LYN, and CYBB as potentially critical ERSRGs associated with advanced atherosclerotic plaque, demonstrating their good diagnostic utility and offering novel insights into the potential pathobiology of AS progression, paving the way for exploring innovative therapeutic targets.

Visualizing Endoplasmic Reticulum Stress and Autophagy in Alzheimer's Model Cells by a Peroxynitrite-Responsive AIEgen Fluorescent Probe

Endoplasmic reticulum (ER) stress and autophagy (ER-phagy) occurring in nerve cells are crucial physiological processes closely associated with Alzheimer's disease (AD). Visualizing the two processes is paramount to advance our understanding of AD pathologies. Among the biomarkers identified, peroxynitrite (ONOO-) emerges as a key molecule in the initiation and aggravation of ER stress and ER-phagy, highlighting its significance in the underlying mechanisms of the two processes. In this work, we designed and synthesized an innovative ONOO--responsive AIEgen-based fluorescent probe (DHQM) with the ability to monitor ER stress and ER-phagy in AD model cells. DHQM demonstrated excellent aggregation-induced emission (AIE) properties, endowing it with outstanding ability for washing-free intracellular imaging. Meanwhile, it exhibited high sensitivity, remarkable selectivity to ONOO-, and exceptional ER-targeting ability. The probe was successfully applied for fluorescence imaging of ER ONOO- fluctuations to assess the ER stress status in aluminum-induced AD model cells. Our findings revealed that aluminum-induced ferroptosis, a regulated cell death process, was pivotal in the excessive ONOO- production, which in turn activated and exacerbated ER stress. Furthermore, the aluminum-stimulated ER-phagy was observed utilizing DHQM, which might be crucial in inhibiting ferroptosis and mitigating aberrant ER stress. Overall, this study not only offers valuable insights into the pathological mechanisms of AD at the ER level but also opens new potential therapeutic avenues targeting these pathways.

Proteomics: An In-Depth Review on Recent Technical Advances and Their Applications in Biomedicine

Proteins hold pivotal importance since many diseases manifest changes in protein activity. Proteomics techniques provide a comprehensive exploration of protein structure, abundance, and function in biological samples, enabling the holistic characterization of overall changes in organisms. Nowadays, the breadth of emerging methodologies in proteomics is unprecedentedly vast, with constant optimization of technologies in sample processing, data collection, data analysis, and its scope of application is steadily transitioning from the bench to the clinic. Here, we offer an insightful review of the technical developments in proteomics and its applications in biomedicine over the past 5 years. We focus on its profound contributions in profiling disease spectra, discovering new biomarkers, identifying promising drug targets, deciphering alterations in protein conformation, and unearthing protein-protein interactions. Moreover, we summarize the cutting-edge technologies and potential breakthroughs in the proteomics pipeline and provide the principal challenges in proteomics. Based on these, we aspire to broaden the applicability of proteomics and inspire researchers to enhance our understanding of complex biological systems by utilizing such techniques.

Activation of protein kinase B rescues against thapsigargin-elicited cardiac dysfunction through regulation of NADPH oxidase and ferroptosis

Endoplasmic reticulum (ER) stress is a known contributor to cardiac remodeling and contractile dysfunction. Although NADPH oxidase has been implicated in ER stress-induced organ damage, its specific role in myocardial complications resulting from ER stress remains unclear. This study aimed to investigate the possible involvement of NADPH oxidase in ER stress-induced myocardial abnormalities and to evaluate the impact of Akt constitutive activation on these myocardial defects. Mice with cardiac-specific overexpression of active mutant of Akt (Myr-Akt) and their wild-type (WT) littermates were treated with ER stress instigator thapsigargin (1 mg/kg, i. p. 72 hrs) before evaluating myocardial morphology and function. Our results noted that thapsigargin significantly impaired echocardiographic parameters and cell shortening indices, including elevated LVESD, decreased ejection fraction, fractional shortening, peak shortening, electrically-stimulated intracellular Ca2+ release, and cardiomyocyte survival. These functional deteriorations were accompanied by upregulation of NADPH oxidase, O2- production, mitochondrial damage, carbonyl formation, lipid peroxidation, apoptosis, and interstitial fibrosis, with unchanged myocardial size. Constitutive Akt hyperactivation did not generate any response on myocardial morphology and function, although it greatly suppressed or nullified thapsigargin-induced myocardial remodeling and dysfunction. Thapsigargin also triggered dephosphorylation of Akt and its downstream signal GSK3β, along with development of ferroptosis, all of which were nullified by Akt hyperactivation. In vitro studies further revealed that thapsigargin provoked cardiomyocyte mechanical anomalies and lipid peroxidation, similar to in vivo results. These effects were reverted by inhibitors of NADPH oxidase and ferroptosis (apocynin and LIP1). Collectively, our data denote an important protective role for Akt hyperactivation in thapsigargin-evoked myocardial anomalies, likely through NADPH oxidase-mediated regulation of ferroptosis.

The first ER-targeting flavone-based fluorescent probe for Cys: Applications in real-time tracking in an epilepsy model and food analysis

Epilepsy is one of the most commonly-seen neurological disorders, and both endoplasmic reticulum stress (ERS) and oxidative stress (OS) have been demonstrated to be associated with epileptic seizures. As one of the three endogenous thiol-containing amino acids, cysteine (Cys) is recognized not only as an important biomarker of various biological processes but also widely used as a significant additive in the food industry. However, the exact role that Cys plays in ERS has not been well answered up to now. In this paper, we reported the first flavone-based fluorescent probe (namely BFC) with nice endoplasmic reticulum (ER)-targeting ability, which was capable of monitoring Cys in a fast response (3.0 min), large stokes shift (130 nm) and low detection limit (10.4 nM). The recognition mechanism of Cys could be attributed to the addition-cyclization reaction involving a Cys residue and an acrylate group, resulting in the release of the strong excited-state intramolecular proton transfer (ESIPT) emission molecule of benzoflavonol (BF). The low cytotoxicity and good biocompatibility of the probe BFC allowed for monitoring the fluctuation of endogenous Cys levels under both ERS and OS processes, as well as in zebrafish models of epilepsy. Quantitative determination of Cys with the probe BFC was also achieved in three different food samples. Additionally, a probe-immersed test strips integrated with a smartphone device was successfully constructed for on-site colorimetric detection of Cys. Undoubtedly, our work provided a valuable tool for tracking Cys levels in both an epilepsy model and real food samples.

Roles of endoplasmic reticulum stress and activating transcription factors in Alzheimer's disease and Parkinson's disease

Endoplasmic reticulum (ER) is a crucial organelle associated with cellular homeostasis. Accumulation of improperly folded proteins results in ER stress, accompanied by the reaction involving triggering unfolded protein response (UPR). The UPR is mediated through ER membrane-associated sensors, such as protein kinase-like ER kinase (PERK), inositol-requiring transmembrane kinase/endoribonuclease 1α, and activating transcription factor 6 (ATF6). Prolonged stress triggers cell apoptotic reaction, resulting in cell death. Neuronal cells are especially susceptible to protein misfolding. Notably, ER and UPR malfunctions are linked to many neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD), delineated by accumulation of misfolded proteins. Notably, ATF family members play key roles in AD and PD pathogenesis. However, the connection between ER stress, UPR, and neuropathology is not yet fully understood. Here, we discuss our present knowledge of the association between ER stress, the UPR, and neurodegeneration in AD and PD. We also discuss the roles of ATF family members in AD and PD pathogenesis. Moreover, we provide a mechanistic clarification of how disease-related molecules affect ER protein homeostasis and explore recent findings that connect the UPR to neuronal plasticity.

TRIM3 modulates cisplmatin-resistant of cervical squamous cell carcinoma via endoplasmic reticulum stress signaling in vitro

TRIM3 is widely recognized as a tumor suppressor gene. However, its precise role in cervical squamous cell carcinoma (CESC) remains elusive. Here, we observed a significant decrease in the expression of TRIM3 in CESC cells. Overexpression of TRIM3 suppresses cell proliferation and clonal formation. Through the establishment of cisplatin (cDDP)-resistant CESC cell lines, we discovered that the expression of TRIM3 was further downregulated in cDDP-resistant cells, while overexpression of TRIM3 enhanced cellular sensitivity to cDDP. Mechanistic investigations revealed that TRIM3 directly interacts with GRP78, a crucial protein involved in endoplasmic reticulum stress (ERS) pathway, promoting its ubiquitination degradation. Under cDDP treatment, the overexpression of TRIM3 in cDDP-resistant cells suppressed cell proliferation and downregulated the expression of drug-resistant genes, while simultaneously enhancing the activation of apoptosis signaling pathways. However, co-expression of TRIM3 and GRP78 restored cellular sensitivity to cDDP back to normal levels. Consequently, overexpressing TRIM3 in drug-resistant cells facilitates PERK activation and subsequent induction of apoptosis through inhibition of GRP78, ultimately suppressing drug resistance and inducing apoptosis in CESC cells. In conclution, our study suggests that the TRIM3/GRP78 axis regulates cDDP resistance in CESC cells by modulating the downstream apoptotic pathway of ERS.

Cardiomodulatory Effects of Cardiometabolic and Antihyperglycemic Medications: The Roles of Oxidative and Endoplasmic Reticulum Stress

Uncontrolled hyperglycemia in people with diabetes is an established risk of premature cardiovascular disease. Repeated hypoglycemic events are also associated with increased cardiovascular mortality. Both hyperglycemia and hypoglycemia induce cellular stress, notably endoplasmic reticulum (ER) stress, a known promoter of cardiovascular disease. Contemporary anti-hyperglycemic drugs such as glucagon-like peptide 1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 (SGLT-2) inhibitors simultaneously inhibit oxidative stress and ER stress in human coronary artery endothelial cells. Similarly, other known cardioprotective drugs, such as statins and inhibitors of the renin-angiotensin-aldosterone system (RAAS) share a common pleiotropic effect of reducing cellular stress. Antioxidants reduce oxidative stress but may aggravate ER stress. This dichotomy of antioxidant effects may underline the unfavorable outcomes of clinical trials with antioxidant vitamin use. The aim of this review is to highlight the potential role of cellular stress reduction in cardioprotective effects of contemporary diabetes drugs. Future clinical trials are needed to test the hypothesis that cellular stress is the fundamental culprit in cardiovascular disease.

Targeting endoplasmic reticulum stress as a potential therapeutic strategy for diabetic cardiomyopathy

Endoplasmic reticulum (ER) is an essential organelle involved in vesicular transport, calcium handling, protein synthesis and folding, and lipid biosynthesis and metabolism. ER stress occurs when ER homeostasis is disrupted by the accumulation of unfolded and/or misfolded proteins in the ER lumen. Adaptive pathways of the unfolded protein response (UPR) are activated to maintain ER homeostasis. In obesity and type 2 diabetes mellitus (T2DM), accumulating data indicate that persistent ER stress due to maladaptive UPR interacts with insulin/leptin signaling, which may be the potential and central mechanistic link between obesity-/T2DM-induced metabolic dysregulation (chronic hyperglycemia, dyslipidemia and lipotoxicity in cardiomyocytes), insulin/leptin resistance and the development of diabetic cardiomyopathy (DiabCM). Meanwhile, these pathological conditions further exacerbate ER stress. However, their interrelationships and the underlying molecular mechanisms are not fully understood. A deeper understanding of ER stress-mediated pathways in DiabCM is needed to develop novel therapeutic strategies. The aim of this review is to discuss the crosstalk between ER stress and leptin/insulin signaling and their involvement in the development of DiabCM focusing on mitochondria-associated ER membranes and chronic inflammation. We also present the current direction of drug development and important considerations for translational research into targeting ER stress for the treatment of DiabCM.

PDIA3 rs2788: An Independent Risk Factor for Hypertension and Its Interaction With Antihypertensive Medications

Hypertension is a multifactorial condition influenced by both genetic and environmental factors. Protein disulfide isomerase family A member 3 (PDIA3) is a key endoplasmic reticulum protein which may contribute to increased blood pressure. However, the relationship between PDIA3 polymorphisms and hypertension remain unclear. This study aims to explore the relationship between PDIA3 polymorphisms and hypertension. First, Mendelian randomization (MR) analyses were performed to assess the causal link between PDIA3 and hypertension. Second, key gene polymorphism on PDIA3 was identified using online databases and analyzed with Haploview software. Third, multivariate-adjusted logistic regression analyses were employed to evaluate the associations between PDIA3 rs2788 and hypertension. Finally, stratified analyses were conducted to further assess interactions between PDIA3 rs2788 and antihypertensive medications. MR analyses indicated a causal relationship between PDIA3 and hypertension. The rs2788 gene polymorphism locus on PDIA3 was identified using online databases and Haploview software. Multivariable-adjusted logistic regression analyses revealed that PDIA3 rs2788 was an independent risk for hypertension (OR: 4.603, 95% CI: 2.946-7.194; p < 0.001). Significant interactions were identified between PDIA3 and antihypertensive medications, particularly ACEI/ARB treatments (p = 0.013 for interaction). Similar findings were observed regarding the causal relationship between antihypertensive treatments and hypertension. PDIA3, particularly its rs2788 polymorphisms, may represent a novel biomarker for hypertension. These findings may contribute to the development of targeted screening strategies and personalized treatment approaches for hypertension management.

From Ca2+ dysregulation to heart failure: β-adrenoceptor activation by RKIP postpones molecular damages and subsequent cardiac dysfunction in mice carrying mutant PLNR9C by correction of aberrant Ca2+-handling

Impaired cardiomyocyte Ca2+ handling is a central hallmark of heart failure (HF), which causes contractile dysfunction and arrhythmias. However, the underlying molecular mechanisms and the precise contribution of defects in Ca2+-cycling regulation in the development of HF are still not completely resolved. Here, we used transgenic mice that express a human mutation in the cardiomyocyte Ca2+-regulator phospholamban (PLNR9C-tg) causing severe HF due to a reduction in Ca2+ reuptake into the sarco(endo)plasmic reticulum (SR). PLNR9C-induced HF is a rapidly progressing condition characterized by prominent Ca2+ cycling and relaxation defects and premature death of mutation carriers. We found that endoplasmic reticulum (ER) and mitochondrial function are affected even before transition to overt HF. Early correction of aberrant Ca2+ cycling by cardiac expression of the Raf kinase inhibitor protein (RKIP), an endogenous activator of β-adrenoceptors (βAR), delayed the cellular alterations, functional failure and prolonged lifespan. Our study highlights the importance of early and persistent correction of Ca2 + dynamics, not only for excitation/contraction coupling, but also for the prevention of rather irreparable events on cardiac energetics and ER stress adaptations. The latter may even impede with later onset of Ca2+-related therapeutic interventions and should gain more focus for HF treatment.

Roles of X-box binding protein 1 in liver pathogenesis

The prevalence of drug-induced liver injury (DILI) and viral liver infections presents significant challenges in modern healthcare and contributes to considerable morbidity and mortality worldwide. Concurrently, metabolic dysfunctionassociated steatotic liver disease (MASLD) has emerged as a major public health concern, reflecting the increasing rates of obesity and leading to more severe complications such as fibrosis and hepatocellular carcinoma. X-box binding protein 1 (XBP1) is a distinct transcription factor with a basic-region leucine zipper structure, whose activity is regulated by alternative splicing in response to disruptions in endoplasmic reticulum (ER) homeostasis and the unfolded protein response (UPR) activation. XBP1 interacts with a key signaling component of the highly conserved UPR and is critical in determining cell fate when responding to ER stress in liver diseases. This review aims to elucidate the emerging roles and molecular mechanisms of XBP1 in liver pathogenesis, focusing on its involvement in DILI, viral liver infections, MASLD, fibrosis/cirrhosis, and liver cancer. Understanding the multifaceted functions of XBP1 in these liver diseases offers insights into potential therapeutic strategies to restore ER homeostasis and mitigate liver damage.

β-Hydroxybutyrate Alleviates Atherosclerotic Calcification by Inhibiting Endoplasmic Reticulum Stress-Mediated Apoptosis via AMPK/Nrf2 Pathway

BACKGROUND

Atherosclerotic calcification (AC) is a common feature of atherosclerotic cardiovascular disease. β-Hydroxybutyrate (BHB) has been identified as a molecule that influences cardiovascular disease. However, whether BHB can influence AC is still unknown.

METHODS AND RESULTS

In this study, ApoE-/- mice, fed a Western diet, were used to examine the effects of BHB on AC. Rat vascular smooth muscle cells (VSMCs) were used to verify the impacts of BHB on AC and to explore the underlying mechanisms. The results show that Western diet-challenged ApoE-/- mice, supplemented with BHB for 24 weeks, exhibited reduced calcified areas, calcium content, and alkaline phosphatase (ALP) activity in the aortas, as well as ameliorated severity of AC. Furthermore, BHB downregulated the expression of glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP), thereby reducing endoplasmic reticulum stress (ERS) and ERS-mediated apoptosis in the aortas of the mice. Consistently, in vitro studies showed that BHB reduced ALP activity and calcium content in VSMCs, and inhibited VSMC calcification. Additionally, BHB suppressed ERS-mediated apoptosis in VSMCs.

CONCLUSIONS

In summary, the present results demonstrate that BHB can alleviate atherosclerotic calcification by inhibiting ERS-mediated apoptosis. Therefore, BHB may serve as a viable therapeutic agent for AC.

Ischemic Stroke Induces ROS Accumulation, Maladaptive Mitophagy, and Neuronal Apoptosis in Minipigs

Reactive oxygen species (ROS)-induced adaptive/maladaptive mitophagy plays an essential role in the pathophysiology of acute ischemic stroke (AIS). However, most studies have been conducted using rodent models, which limits their clinical application. In this study, we aimed to develop porcine models of permanent stroke and observe the pathophysiological alterations caused by acute ischemic stroke, focusing on ROS-induced mitophagy. Miniature pigs were subjected to lateral frontotemporal electrocoagulation, which resulted in permanent middle cerebral artery occlusion. We investigated global brain damage and mechanisms of adaptive/maladaptive mitophagy caused by ROS and global brain inflammation after AIS. An early neuroinflammatory response was observed in the ipsilateral hemisphere. ROS levels were significantly elevated in the ipsilateral hemisphere and slightly elevated in the contralateral hemisphere. ROS accumulation may be attributed to the increased production and impaired elimination of ROS. In addition, mitophagy and apoptosis were detected in the ischemic core, which may be attributed to ROS accumulation. We propose "distinct-area targeting" interventions aimed at maladaptive mitophagy within the ischemic core of the infarct hemisphere, which may provide new therapeutic targets for the treatment of AIS.

SUCNR 1 promotes atherosclerosis by inducing endoplasmic reticulum stress mediated ER-mito crosstalk

Atherosclerosis is a progressive inflammatory disease within the large and medium arteries. SUCNR1(Succinate receptor 1) has been reported to regulate the inflammatory response in cardiovascular diseases, but how it works in atherosclerosis remains unclear. In this study, we observed that SUCNR1 is upregulated in endothelial cells within human atherosclerotic lesions. The deletion of SUCNR1 in vascular endothelial cells can mitigate the progression of atherosclerotic lesions in high-fat diet ApoE-/- mice. The overexpression or activation of SUCNR1 intensified endoplasmic reticulum stress and mitochondria-endoplasmic reticulum interactions. Moreover, SUCNR1 exacerbated mitochondrial injury, mtDNA leakage, and the activation of cGAS-STING signaling. Elevated mitochondrial damage, ER-mitochondrial interactions, and inflammation induced by SUCNR1 activation were blocked by the endoplasmic reticulum stress inhibitor. Collectively, these findings suggest that SUCNR1 promotes atherosclerosis through endoplasmic reticulum stress signaling mediated ER-mitochondrial crosstalk and its downstream cGAS-STING pathway. Our results provide new insights into the mechanism of SUCNR1 in atherosclerosis and inhibiting endoplasmic reticulum stress signaling may provide a promising strategy to prevent and treat atherosclerosis.

Endoplasmic reticulum protein TXNDC5 modulates thyroid eye disease TGF-β1-induced myofibroblast transdifferentiation

AIM

There remain limited therapies to treat thyroid eye disease (TED) orbital fibrosis, highlighting the urgency to develop novel targets. Transforming growth factor-β1 (TGF-β1)-induced myofibroblast transdifferentiation from orbital fibroblasts are important pathogenetic factor of TED. Endoplasmic reticulum (ER) stress may play a role in TED pathogenesis since it has been linked to liver, kidney, heart and lung fibrotic remodelling. We would evaluate the role of thioredoxin domain containing 5 (TXNDC5), a fibroblast-enriched ER protein, in TGF-β1-induced myofibroblast transdifferentiation from TED orbital fibroblasts.

METHODS

Orbital fibroblasts from patients with TED were treated with TGF-β1 to investigate ER stress-relative gene expression especially for TXNDC5. To determine if TXNDC5 is involved in TGF-β1-induced fibrosis, we transfected TED orbital fibroblasts by lentivirus with a small hairpin RNA of pLKO-TXNDC5 gene (shTXNDC5) to knockdown TXNDC5 protein expression levels. After transfection of shTXNDC5 in TED orbital fibroblast followed by TGF-β1 treatment, we analysed TGF-β1-induced fibrosis protein expression.

RESULTS

We measured increased TXNDC5 gene and protein expression in primary TED orbital fibroblasts. TXNDC5 protein levels were increased in TED orbital fibroblasts under TGF-β1 stimulation (2.5, 5, 10 and 20 ng/mL). Moreover, TXNDC5 knockdown of attenuated TGFβ1 (5 ng/mL)-induced myofibroblast transdifferentiation and extracellular matrix protein upregulation whereas increasing TXNDC5 expression by a recombinant protein of TXNDC5 (rhTXNDC5) addition increased alpha smooth muscle actin, fibronectin and connective tissue growth factor protein expression.

CONCLUSION

In conclusion, targeting TXNDC5 may be a novel therapeutic approach against TGF-β1-induced myofibroblast transdifferentiation in TED orbital fibroblasts.

Role of Quercetin in Diabetic Cardiomyopathy

Diabetic cardiomyopathy is a significant and severe complication of diabetes that affects a large portion of the global population, with its prevalence continuing to rise. Secondary metabolites, including quercetin, have shown promising effects in mitigating the progression of diabetic cardiomyopathy by targeting multiple pathological mechanisms, including impaired insulin signaling, glucotoxicity, lipotoxicity, oxidative stress, inflammation, fibrosis, apoptosis, autophagy, mitochondrial dysfunction, cardiac stiffness, and disrupted calcium handling. Addressing these mechanisms is crucial to prevent left ventricular diastolic and systolic dysfunction in advanced stages of diabetic heart disease. Scientific evidence has highlighted the cardioprotective properties of quercetin at both the myocardial and cellular/molecular levels in diabetic models. Therefore, this review aims to present a comprehensive overview of the proposed mechanisms underlying quercetin's beneficial effects, providing valuable insights that could inform future drug discovery efforts specific to diabetic cardiomyopathy.

L-3-n-butylphthalide alleviates intermittent alcohol exposure-induced hypothalamic cell apoptosis via inhibiting the IRE1α-ASK1-JNK pathway in adolescent rats

Exposure to alcohol can induce different degrees of damage to various tissues and organs, and brain is the most vulnerable part affected by alcohol. However, there is no detailed report on whether intermittent alcohol exposure can result in pathological changes in the hypothalamus of adolescent rats and the detailed mechanism. This study investigated pathological changes in the hypothalamus, probed the levels of inflammatory factors, and detected the expression of proteins related to endoplasmic reticulum stress (ERS) to determine whether ERS is involved in the injury process of the hypothalamus and the protective mechanism of L-3-n-butylphthalide (L-NBP). The results showed that intermittent alcohol exposure induced hypothalamic nerve injury, including cell apoptosis, increased the levels of inflammatory factors, and upregulated the expression of glucose-regulated protein 78 (GRP78), p-Inositol Requiring Enzyme 1α (p-IRE1α), apoptosis signal-regulating kinase 1 (ASK1), and p-c-Jun N-terminal kinase (p-JNK)). Tauroursodeoxycholic acid (TUDCA), an ERS inhibitor, significantly reduced the pathological damage described above. The increases in the levels of inflammatory factors, pathological injury, and increased levels of proteins associated with the IRE1α-ASK1-JNK pathway were alleviated by L-NBP. The present study indicated that intermittent alcohol exposure could lead to hypothalamic cell apoptosis in adolescent rats and L-NBP could alleviate the above injury by inhibiting the IRE1α-ASK1-JNK pathway. Abbreviations: Ang-2, Angiopoietin-2; ASK1, Apoptosis signal-regulating kinase 1; ER, Endoplasmic reticulum; ERS, Endoplasmic reticulum stress; ELISA, Enzyme-linked immunosorbent assay; GFAP, Glial fibrillary acidic protein; GRP78, Glucose-regulated protein 78; IBA1, Ionized calcium binding adapter molecule 1; i.p., Intraperitoneal; IRE1α, Inositol Requiring Enzyme 1α; JNK, c-Jun N-terminal kinase; L-NBP, L-3-n-butylphthalide; PND, Postnatal day; PVDF, Polyvinylidene difluoride; SDS-PAGE, Sodium dodecyl sulfate-polyacrylamide gel electrophoresis; TRAF2, TNF-receptor associated factor 2; TUDCA, Tauroursodeoxycholic acid; VEGF, Vascular endothelial growth factor.

Pathological roles of mitochondrial dysfunction in endothelial cells during the cerebral no-reflow phenomenon: A review

Emergency intravascular interventional therapy is the most effective approach to rapidly restore blood flow and manage occlusion of major blood vessels during the initial phase of acute ischemic stroke. Nevertheless, several patients continue to experience ineffective reperfusion or cerebral no-reflow phenomenon, that is, hypoperfusion of cerebral blood supply after treatment. This is primarily attributed to downstream microcirculation disturbance. As integral components of the cerebral microvascular structure, endothelial cells (ECs) attach importance to regulating microcirculatory blood flow. Unlike neurons and microglia, ECs harbor a relatively low abundance of mitochondria, acting as key sensors of environmental and cellular stress in regulating the viability, structural integrity, and function of ECs rather than generating energy. Mitochondria dysfunction including increased mitochondrial reactive oxygen species levels and disturbed mitochondrial dynamics causes endothelial injury, further causing microcirculation disturbance involved in the cerebral no-reflow phenomenon. Therefore, this review aims to discuss the role of mitochondrial changes in regulating the role of ECs and cerebral microcirculation blood flow during I/R injury. The outcomes of the review will provide promising potential therapeutic targets for future prevention and effective improvement of the cerebral no-reflow phenomenon.

miR-421-mediated suppression of FGF13 as a novel mechanism ameliorates cardiac hypertrophy by inhibiting endoplasmic reticulum stress

Pathological cardiac hypertrophy is an independent risk factor for heart failure. Currently, clinical treatments offer limited effectiveness, and both mortality and morbidity from cardiac hypertrophy and heart failure continue to be significant. Therefore, it is extremely urgent to find new intervention targets to prevent and alleviate pathological cardiac hypertrophy. In this study, we explored FGF13 expression and its upstream regulators in hypertrophic hearts. Firstly, we observed an increase in FGF13 expression levels in human hypertrophic myocardium tissues, as well as in mouse models of TAC-induced hypertrophy and in neonatal rat cardiomyocyte (NRCM) models induced by isoproterenol (ISO). Moreover, these elevated levels of FGF13 were shown to positively correlate with hypertrophic markers, including ANP and BNP. By using both gain-of-function and loss-of-function approaches in an in vitro hypertrophy model, we demonstrated that FGF13 knockdown could inhibit endoplasmic reticulum stress (ERS), thereby ameliorating cardiomyocyte hypertrophy. Meanwhile, we investigated the upstream regulators of FGF13 in hypertrophic hearts, and a dual-luciferase reporter assay confirmed that FGF13 is a direct target of miR-421. Overexpression of miR-421 decreased the protein level of FGF13 and ameliorated ISO-induced cardiomyocyte hypertrophy via modulating ER stress. In contrast, overexpression of FGF13 attenuated the ameliorative effect of miR-421 on ISO-induced cardiomyocyte hypertrophy. Taken together, the present results suggested that miR-421 ameliorated ISO-induced cardiomyocyte hypertrophy by negatively regulating FGF13 expression. This finding may offer a novel approach for the treatment of cardiac hypertrophy.

PAT exposure caused human hepatocytes apoptosis and induced mice subacute liver injury by activating oxidative stress and the ERS-associated PERK pathway

With the widespread use of antimony compounds in synthetic materials and processing, the occupational exposure and environmental pollution caused by antimony have attracted the attention of researchers. Studies have shown that antimony compounds can cause liver damage, but the mechanism has not yet been elucidated. In this study, we used the trivalent potassium antimony tartrate (PAT) to infect L02 hepatocytes and Kunming (KM) mice to establish an antimony-induced apoptosis model of L02 cells and a subacute liver injury model of KM mice. We found that PAT exposure caused hepatocyte apoptosis and was accompanied by oxidative stress and endoplasmic reticulum stress (ERS), and the ERS-associated PERK pathway was activated. Further experimental results showed that N-acetyl-l-cysteine (NAC) pretreatment or silencing of the PERK gene in L02 cells reduced PAT-induced apoptosis. The activity of SOD and CAT in treated L02 cells was increased, the malondialdehyde content in L02 cells and liver tissues was decreased, and the content of ERS-related proteins GRP78 and CHOP, as well as the content of PERK-pathway-related proteins p-PERK/PERK, p-eif2α/eif2α and ATF4 protein were significantly reduced. Overall, PAT exposure triggered hepatocyte apoptosis and liver injury by inducing oxidative stress and activating the ERS-associated PERK pathway; however, this effect could be alleviated by NAC intervention or silencing of PERK in hepatocytes.

Identification of Diagnostically Relevant Biomarkers in Patients with Coronary Artery Disease by Comprehensive Analysis

Background

Peripheral biomarkers are becoming an important method by which to monitor the progression of coronary artery disease (CAD). Not only are they minimally invasive and early detection, but they can also be used for classification and diagnosis of disease as well as prognostic assessment. Currently, this approach is still in the exploratory stage. The purpose of this research is to determine the diagnostic value and therapeutic potential of the endoplasmic reticulum stress (ERS) genes in CAD.

Methods

The clinical information and RNA sequence data were obtained from the GEO database and subsequently subjected to a series of optimization and visualization processes using various analytical techniques, including WGCNA, LASSO, SVM-RFE feature selection, random forest (RF), and XGBoost, as well as R software and Cytoscape. Finally, immunofluorescence was used to validate the analysis.

Results

We identify 6 key ERS differentially expressed genes (ERS-DEGs) (UFL1, HSPA1A, ERLIN1, LRRK2, ERN1, SERINC3) for constructing diagnostic models. They showed qualified diagnostic ability as biomarkers of CAD within training dataset (AUC = 0.803) and validation dataset (AUC = 0.776 and 0.797). Association analyses showed that peripheral immune cells, immune checkpoint genes and Human Leukocyte Antigen (HLA) genes had characteristic distributions in CAD and were closely related to specific ERS genes. Meanwhile, we found that HSPA1A may involve the MAPK signaling pathway in CAD.

Conclusion

We constructed an efficient diagnostic model based on 6 key ERS-DEGs and explored their regulatory networks and effects on the CAD immune microenvironment. UFL1, HSPA1A, ERLIN1, LRRK2, ERN1, SERINC3 are expected to be biomarkers for CAD.

An endoplasmic reticulum stress related signature for clinically predicting prognosis of breast cancer patients

BACKGROUND

Endoplasmic Reticulum Stress (ER stress) was an important event in the development of breast cancer. We aimed to predict prognosis based on ER stress related key genes.

METHODS

Data of the RNA-seq and clinical information of breast cancer cases were downloaded from the TCGA database. A total of 4 genes related with ER stress was identified by the univariate Cox regression and Least Absolute Shrinkage and Selection Operator (LASSO)-penalized Cox proportional hazards regression analysis. The predictive ability of the ER stress model was evaluated by utilizing Kaplan-Meier curves and time-dependent receiver operating characteristic (ROC) curves. Moreover, we verified 4 genes expression and its relationship with clinical breast cancer cases in real-world.

RESULTS

4 genes including RNF186, BCAP31, SERPINA1, TAPBP were identified as a prognostic risk score model. Based on that, we found patients of breast cancer had a better survival with low-risk score. And also, ER stress model showed a good diagnostic efficacy with AUC curve. The risk score was significantly associated with patients' age, T stage and clinical stage. A nomogram was constructed to estimate individual survival. Further GO and KEGG analysis showed our model was related with immune infiltration. Patients of breast cancer with high-risk scores were usually accompanied with poor immune infiltration. It was predicted that high risk group was more sensitive to Vinorelbine, Docetaxel and Cisplatin. At last, we verified the expression of four signature genes using qRT-PCR and immunohistochemistry.

CONCLUSION

Our ER stress model performed a valuable prediction on breast cancer patients.

Endoplasmic Reticulum Stress Induces ROS Production and Activates NLRP3 Inflammasome Via the PERK-CHOP Signaling Pathway in Dry Eye Disease

Purpose

The purpose of this study was to investigate the potential roles of endoplasmic reticulum (ER) stress in the development of dry eye disease (DED).

Methods

Single-cell RNA sequencing (scRNA-seq) data from the Gene Expression Omnibus (GEO) database, derived from corneal tissues of a dry eye mouse model, was processed using the Seurat R program. The results were validated using a scopolamine-induced dry eye mouse model and a hyperosmotic-induced cell model involving primary human corneal epithelial cells (HCECs) and immortalized human corneal epithelial (HCE-2) cells. The HCE-2 cells were treated with 4-phenylbutyric acid (4-PBA) or tunicamycin (TM) to modulate ER stress. TXNIP and PERK knockdown were performed by siRNA transfection. Immunofluorescence, Western blotting, and real-time PCR were used to assess oxidative stress, ER stress, unfolded protein response (UPR) marker proteins, and TXNIP/NLRP3 axis activation.

Results

The analysis of scRNAseq data shows an increase in the ER stress marker GRP78, and the activation of the PERK-CHOP of UPR in DED mouse. These findings were confirmed both in vivo and in vitro. Additionally, HCE-2 cells treated with 4-PBA or TM showed significant effects on the production of reactive oxygen species (ROS) and the activation of the TXNIP/NLRP3-IL1β signaling pathway. Furthermore, siRNA knockdown of PERK or TXNIP, which alleviated the TXNIP/NLRP3-IL1β signaling axis, showed protective effects on HCECs.

Conclusions

This study explores the role of ER stress-induced oxidative stress and NLRP3-IL-1β mediated inflammation in DED, and highlights the therapeutic potential of PERK-CHOP axis and TXNIP in the treatment of DED.

The Tumor Suppressor TPD52-Governed Endoplasmic Reticulum Stress is Modulated by APCCdc20

Aberrant regulation of unfolded protein response (UPR)/endoplasmic reticulum (ER) stress pathway is associated with cancer development, metastasis, and relapse, and the UPR signal transducer ATF6 has been proposed as a diagnostic and prognostic marker for many cancers. However, a causal molecular link between ATF6 activation and carcinogenesis is not established. Here, it is found that tumor protein D52 (TPD52) integrates ER stress and UPR signaling with the chaperone machinery by promoting S2P-mediated cleavage of ATF6. Although TPD52 has been generally considered as an oncogene, TPD52 is identified as a novel tumor suppressor in bladder cancer. Significantly, attenuation of the ER stress via depletion of TPD52 facilitated tumorigenesis in a subset of human carcinomas. Furthermore, the APCCdc20 E3 ligase is validated as the upstream regulator marking TPD52 for polyubiquitination-mediated proteolysis. In addition, inactivation of Cdc20 sensitized cancer cells to treatment with the ER stress inducer in a TPD52-dependent manner. Thus, the study suggests that TPD52 is a novel Cdc20 substrate that may modulate ER stress to prevent tumorigenesis.

Chlorpyrifos-oxon induced neuronal cell death via endoplasmic reticulum stress-triggered apoptosis pathways

Chlorpyrifos (CPF) is one of the organophosphorus pesticides widely used throughout the world. Epidemiological studies suggested a link between CPF exposure and neurologic disorders, while the molecular mechanisms remain inconclusive. In the present study, we investigated the impacts of chlorpyrifos-oxon (CPO), the major toxic CPF metabolite, on cell apoptosis, and explored possible mechanism associated with endoplasmic reticulum (ER) stress in SH-SY5Y cells. Results showed that CPO exposure induced dose-dependent apoptosis and expression of ER stress-related proteins in SH-SY5Y cells. Pretreatment with 4-PBA (an ER stress inhibitor) effectively inhibited the expression of GRP78, GRP94, p-IRE1α, and XBP1-s, and apoptotic events. Pretreatment with STF-083010 (an IRE1α inhibitor) partially attenuated CPO-induced apoptosis. In addition, CPO exposure significantly evoked the generation of reactive oxygen species (ROS) which could be eliminated by pretreatment of 4-PBA. Of note, buffering the ROS generation with antioxidant NAC had little impact on the expression of p-IRE1α, and only partially attenuated CPO-induced apoptosis. In contrast, co-pretreatment with NAC and STF-083010 effectively inhibited CPO-induced apoptotic events. Collectively, our results indicate that CPO exposure exerts neuronal cytotoxicity via ER stress downstream-regulated IRE1α/XBP1 signaling pathway and ROS generation-triggered apoptosis. These findings highlight the role of ER stress in CPF-induced neurotoxicity, and provide a promising target for the intervention of organophosphate-associated neurodegenerative diseases.

Carbon dots induce endoplasmic reticulum stress-mediated lipid dysregulation and embryonic developmental toxicity in zebrafish

Carbon dots (CDs) are widely utilized due to their exceptional physical and chemical properties. Nevertheless, there is a paucity of research examining the potential toxicity of carbon dots to human health, particularly with regard to developmental toxicity. The present study demonstrated that exposure to CDs resulted in increased mortality and malformations in zebrafish embryos. Further bioinformatics analyses indicated that CDs-induced lipid metabolism disorders may represent a significant pathway for developmental toxicity in zebrafish embryos. This can result in aberrant expression of genes involved in lipid metabolism, which ultimately leads to endoplasmic reticulum stress (ERS)-induced accumulation of excess lipids in the body. It can therefore be surmised that exposure to CDs in early life ultimately leads to developmental toxicity by inducing ERS-induced lipid metabolism disorders. The findings of this study suggest that there is a risk of long-term exposure to CDs from early life, and provide a theoretical basis and data support for the prevention of potential hazards of CDs.

Research progress and advances in endoplasmic reticulum stress regulation of acute kidney injury

Acute kidney injury (AKI) is a common and severe clinical disorder in which endoplasmic reticulum (ER) stress plays an important regulatory role. In this review, we summarize the research progress on the relationship between ER stress and AKI. It emphasizes the importance of maintaining a balance between promoting and protecting ER stress during AKI and highlights the potential of ER stress-targeted drugs as a new therapeutic approach for AKI. The article also discusses the need for developing drugs that target ER stress effectively while avoiding adverse effects on normal cells and tissues. The review concludes that with a more comprehensive understanding of ER stress mechanisms and advancements in research techniques, more effective treatment options for AKI can be developed in the future.

NLRX1 attenuates endoplasmic reticulum stress via STING in cardiac hypertrophy

Endoplasmic reticulum stress-induced cell apoptosis is a pivotal mechanism underlying the progression of cardiac hypertrophy. NLRX1, a member of the NOD-like receptor family, modulates various cellular processes, including STING, NF-κB, MAPK pathways, reactive oxygen species production, essential metabolic pathways, autophagy and cell death. Emerging evidence suggests that NLRX1 may offer protection against diverse cardiac diseases. However, the impacts and mechanisms of NLRX1 on endoplasmic reticulum stress in cardiac hypertrophy remains largely unexplored. In our study, we observed that the NLRX1 and phosphorylated STING (p-STING) were highly expressed in both hypertrophic mouse heart and cellular model of cardiac hypertrophy. Whereas over-expression of NLRX1 mitigated the expression levels of p-STING, as well as the endoplasmic reticulum stress markers, including transcription activating factor 4 (ATF4), C/EBP homologous protein (CHOP) and the ratios of phosphorylated PERK to PERK, phosphorylated IRE1 to IRE1 and phosphorylated eIF2α to eIF2α in an Angiotensin II (Ang II)-induced cellular model of cardiac hypertrophy. Importantly, the protective effects of NLRX1 were attenuated upon pretreatment with the STING agonist, DMXAA. Our findings provide the evidence that NLRX1 attenuates the PERK-eIF2α-ATF4-CHOP axis of endoplasmic reticulum stress response via inhibition of p-STING in Ang II-treated cardiomyocytes, thereby ameliorating the development of cardiac hypertrophy.

Recent advances in reactive oxygen species (ROS)-responsive drug delivery systems for photodynamic therapy of cancer

Reactive oxygen species (ROS)-responsive drug delivery systems (DDSs) have garnered significant attention in cancer research because of their potential for precise spatiotemporal drug release tailored to high ROS levels within tumors. Despite the challenges posed by ROS distribution heterogeneity and endogenous supply constraints, this review highlights the strategic alliance of ROS-responsive DDSs with photodynamic therapy (PDT), enabling selective drug delivery and leveraging PDT-induced ROS for enhanced therapeutic efficacy. This review delves into the biological importance of ROS in cancer progression and treatment. We elucidate in detail the operational mechanisms of ROS-responsive linkers, including thioether, thioketal, selenide, diselencide, telluride and aryl boronic acids/esters, as well as the latest developments in ROS-responsive nanomedicines that integrate with PDT strategies. These insights are intended to inspire the design of innovative ROS-responsive nanocarriers for enhanced cancer PDT.

Autophagy modulators in type 2 diabetes: A new perspective

Type 2 diabetes (T2D) is a chronic metabolic disorder caused by defective insulin signaling, insulin resistance, and impairment of insulin secretion. Autophagy is a conserved lysosomal-dependent catabolic cellular pathway involved in the pathogenesis of T2D and its complications. Basal autophagy regulates pancreatic β-cell function by enhancing insulin release and peripheral insulin sensitivity. Therefore, defective autophagy is associated with impairment of pancreatic β-cell function and the development of insulin rersistance (IR). However, over-activated autophagy increases apoptosis of pancreatic β-cells leading to pancreatic β-cell dysfunction. Hence, autophagy plays a double-edged sword role in T2D. Therefore, the use of autophagy modulators including inhibitors and activators may affect the pathogenesis of T2D. Hence, this review aims to clarify the potential role of autophagy inhibitors and activators in T2D.

Gnetupendin A protects against ischemic stroke through activating the PI3K/AKT/mTOR-dependent autophagy pathway

BACKGROUND

Autophagy has been recently emerged as a prominent factor in the pathogenesis of ischemic stroke (IS) and is increasingly being considered as a potential therapeutic target for IS. Gnetum parvifolium has been identified as a potential therapeutic agent for inflammatory diseases such as rheumatism and traumatic injuries. However, the pharmacological effects of Gnetupindin A (GA), a stilbene compound isolated from Gnetum parvifolium, have not been fully elucidated until now.

OBJECTIVE

Here we identified the therapeutic potential of GA for IS, deeply exploring the possible mechanisms related to its regulation of autophagy.

METHODS

The mouse model of middle cerebral artery occlusion-reperfusion (MCAO/R) and the oxygen-glucose deprivation reperfusion (OGD/R)-exposed cells served as models to study the protection of GA against IS. The adeno-associated virus (AAV) encoding shAtg5, in conjunction with autophagy inhibitor 3-Methyladenine (3-MA) were utilized to explore the role of GA in regulating autophagy following IS. Molecular docking, CETSA, and DARTS were used to identify the specific therapeutic target of GA. PI3K inhibitor LY294002 was employed to test the participation of PI3K in GA-mediated autophagy and neuroprotective effects following IS.

RESULTS

Our findings revealed that treatment with GA significantly alleviated the brain infract volume, edema, improved neurological deficits and attenuated apoptosis. Mechanistically, we found that GA promoted autophagic flow both in vivo and in vitro after IS. Notably, neural-targeted knockdown of Atg5 abolished the neuroprotective effects mediated by GA. Inhibition of autophagy using 3-MA blocked the attenuation on apoptosis induced by GA. Moreover, molecular docking, CETSA, and DARTS analysis demonstrated that GA specifically targeted PI3K and further inhibited the activation of PI3K/AKT/mTOR signaling pathway. LY294002, which inhibits PI3K, reversed GA-induced autophagy and neuroprotective effects on OGD/R-treated cells.

CONCLUSION

We demonstrated, for the first time, that GA protects against IS through promoting the PI3K/AKT/mTOR-dependent autophagy pathway. Our findings provide a novel mechanistic insight into the anti-IS effect of GA in regulating autophagy.

CTGF regulated by ATF6 inhibits vascular endothelial inflammation and reduces hepatic ischemia-reperfusion injury

Vascular endothelial inflammation is crucial in hepatic ischemia-reperfusion injury (IRI). Our previous research has shown that connective tissue growth factor (CTGF), secreted by endothelial cells, protects against acute liver injury, but its upstream mechanism is unclear. We aimed to clarify the protective role of CTGF in endothelial cell inflammation during IRI and reveal the regulation between endoplasmic reticulum stress-induced activating transcription factor 6 (ATF6) and CTGF. Hypoxia/reoxygenation in endothelial cells, hepatic IRI in mice and clinical specimens were used to examine the relationships between CTGF and inflammatory factors and determine how ATF6 regulates CTGF and reduces damage. We found that activating ATF6 promoted CTGF expression and reduced liver damage in hepatic IRI. In vitro, activated ATF6 upregulated CTGF and downregulated inflammation, while ATF6 inhibition had the opposite effect. Dual-luciferase assays and chromatin immunoprecipitation confirmed that activated ATF6 binds to the CTGF promoter, enhancing its expression. Activated ATF6 increases CTGF and reduces extracellular regulated protein kinase 1/2 (ERK1/2) phosphorylation, decreasing inflammatory factors. Conversely, inhibiting ATF6 decreases CTGF and increases the phosphorylation of ERK1/2, increasing inflammatory factor levels. ERK1/2 inhibition reverses this effect. Clinical samples have shown that CTGF increases after IRI, inversely correlating with inflammatory cytokines. Therefore, ATF6 activation during liver IRI enhances CTGF expression and reduces endothelial inflammation via ERK1/2 inhibition, providing a novel target for diagnosing and treating liver IRI.

The therapeutic effects of salvianolic acids on ischemic stroke: From molecular mechanisms to clinical applications

Ischemic stroke (IS), primarily caused by cerebrovascular occlusion, poses a significant public health challenge with limited effective therapeutic options. Evidence suggests that salvianolic acids (SAs), mainly from Salvia miltiorrhiza Bunge, have been formulated into injections and are widely used in clinical treatments for cardiovascular and cerebrovascular diseases, including stroke. The pharmacological properties of SAs include reducing neuroinflammation, alleviating oxidative stress injury, inhibiting cellular apoptosis, preserving endothelial function, maintaining blood-brain barrier integrity, and promoting angiogenesis. Salvianolic acids for injection (SAFI) serve as a safe and effective treatment option for cardiovascular and cerebrovascular conditions by influencing various signaling pathways and molecular targets associated with these diseases. In this review, we first discuss the pathogenesis of IS, then summarize the classification of SAs, elaborate detailed molecular mechanisms of their efficacy, and the related clinical applications of SAFI. We also emphasize the recent pharmacological advancements and therapeutic possibilities of this promising drug preparation derived from herbs for cerebrovascular conditions.

Mitochondrial Dysfunction in Cardiac Disease: The Fort Fell

Myocardial cells and the extracellular matrix achieve their functions through the availability of energy. In fact, the mechanical and electrical properties of the heart are heavily dependent on the balance between energy production and consumption. The energy produced is utilized in various forms, including kinetic, dynamic, and thermal energy. Although total energy remains nearly constant, the contribution of each form changes over time. Thermal energy increases, while dynamic and kinetic energy decrease, ultimately becoming insufficient to adequately support cardiac function. As a result, toxic byproducts, unfolded or misfolded proteins, free radicals, and other harmful substances accumulate within the myocardium. This leads to the failure of crucial processes such as myocardial contraction-relaxation coupling, ion exchange, cell growth, and regulation of apoptosis and necrosis. Consequently, both the micro- and macro-architecture of the heart are altered. Energy production and consumption depend on the heart's metabolic resources and the functional state of the cardiac structure, including cardiomyocytes, non-cardiomyocyte cells, and their metabolic and energetic behavior. Mitochondria, which are intracellular organelles that produce more than 95% of ATP, play a critical role in fulfilling all these requirements. Therefore, it is essential to gain a deeper understanding of their anatomy, function, and homeostatic properties.

Exploring Potential Diagnostic Biomarkers for Mechanical Asphyxia in the Heart Based on Proteomics Technology

Mechanical asphyxia presents a challenging diagnostic issue in forensic medicine due to its often covert nature, and the signs visible during an autopsy are usually not specific. Despite some progress in understanding hypoxia's effects, traditional methods' inherent limitations might overlook new biomarkers in mechanical asphyxia. This study employed 4D-DIA proteomics to explore the protein expression profiles of cardiac samples under conditions of mechanical asphyxia. Proteomic analysis identified 271 and 371 differentially expressed proteins in the strangulation and suffocation groups, respectively, compared to the control group. Seventy-eight differentially expressed proteins were identified across different mechanical asphyxia groups compared to the control group. GO and KEGG analysis showed enrichment in pathways, including complement and coagulation cascades, cAMP and cGMP-PKG signaling pathways, inflammatory mediator regulation of TRP channels, and phagosomes. Through stringent selection based on protein interactions, ALKBH5, NAA10, and CLPB were identified as potential diagnostic biomarkers. ALKBH5 showed increased expression in asphyxia models, while NAA10 and CLPB were downregulated; these biomarker changes were validated in both animal models and human cardiac samples. This study highlights the potential of proteomics in discovering reliable biomarkers, which can enhance the specificity of mechanical asphyxia diagnosis in forensic practice, provide new insights into the pathophysiological mechanisms of mechanical asphyxia, and offer new perspectives for diagnosing mechanical asphyxia.

Dysregulation of RAS proteostasis by autosomal-dominant LZTR1 mutation induces Noonan syndrome-like phenotypes in mice

Leucine-zipper-like posttranslational regulator 1 (LZTR1) is a member of the BTB-Kelch superfamily, which regulates the RAS proteostasis. Autosomal dominant (AD) mutations in LZTR1 have been identified in patients with Noonan syndrome (NS), a congenital anomaly syndrome. However, it remains unclear whether LZTR1 AD mutations regulate the proteostasis of the RAS subfamily molecules or cause NS-like phenotypes in vivo. To elucidate the pathogenesis of LZTR1 mutations, we generated 2 LZTR1 mutation knock-in mice (Lztr1G245R/+ and Lztr1R409C/+), which correspond to the human p.G248R and p.R412C mutations, respectively. LZTR1-mutant male mice exhibit low birth weight, distinctive facial features, and cardiac hypertrophy. Cardiomyocyte size and the expression of RAS subfamily members, including MRAS and RIT1, were significantly increased in the left ventricles (LVs) of mutant male mice. LZTR1 AD mutants did not interact with RIT1 and functioned as dominant-negative forms of WT LZTR1. Multi-omics analysis revealed that the mitogen-activated protein kinase (MAPK) signaling pathway was activated in the LVs of mutant mice. Treatment with the MEK inhibitor trametinib ameliorated cardiac hypertrophy in mutant male mice. These results suggest that the MEK/ERK pathway is a therapeutic target for the NS-like phenotype resulting from dysfunction of RAS proteostasis by LZTR1 AD mutations.

Mitochondrial structure and function: A new direction for the targeted treatment of chronic liver disease with Chinese herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Excessive fat accumulation, biological clock dysregulation, viral infections, and sustained inflammatory responses can lead to liver inflammation, fibrosis, and cancer, thus promoting the development of chronic liver disease. A comprehensive understanding of the etiological factors leading to chronic liver disease and the intrinsic mechanisms influencing its onset and progression can aid in identifying potential targets for targeted therapy. Mitochondria, as key organelles that maintain the metabolic homeostasis of the liver, provide an important foundation for exploring therapeutic targets for chronic liver disease. Recent studies have shown that active ingredients in herbal medicines and their natural products can modulate chronic liver disease by influencing the structure and function of mitochondria. Therefore, studying how Chinese herbs target mitochondrial structure and function to treat chronic liver diseases is of great significance.

AIM OF THE STUDY

Investigating the prospects of herbal medicine the Lens of chronic liver disease based on mitochondrial structure and function.

MATERIALS AND METHODS

A computerized search of PubMed was conducted using the keywords "mitochondrial structure", "mitochondrial function", "mitochondria and chronic liver disease", "botanicals, mitochondria and chronic liver disease".Data from the Web of Science and Science Direct databases were also included. The research findings regarding herbal medicines targeting mitochondrial structure and function for the treatment of chronic liver disease are summarized.

RESULTS

A computerized search of PubMed using the keywords "mitochondrial structure", "mitochondrial function", "mitochondria and chronic liver disease", "phytopharmaceuticals, mitochondria, and chronic liver disease", as well as the Web of Science and Science Direct databases was conducted to summarize information on studies of mitochondrial structure- and function-based Chinese herbal medicines for the treatment of chronic liver disease and to suggest that the effects of herbal medicines on mitochondrial division and fusion.The study suggested that there is much room for research on the influence of Chinese herbs on mitochondrial division and fusion.

CONCLUSIONS

Targeting mitochondrial structure and function is crucial for herbal medicine to combat chronic liver disease.