Endoplasmic reticulum stress response is involved in nonsteroidal anti-inflammatory drug-induced apoptosis

Relocating NSAIDs into the endoplasmic reticulum induces ER stress-mediated apoptosis in cancer cells

The endoplasmic reticulum (ER) is a vital subcellular organelle that orchestrates numerous essential biological processes, including protein synthesis and processing. Disruption of ER function can lead to ER stress, a condition closely associated with the progression and development of cancer. Consequently, inducing ER stress in cancer cells has emerged as an unconventional yet promising therapeutic approach. However, selectively targeting the ER within cancer cells remains a significant challenge. To address this, we have designed and synthesized a novel small-molecule library composed of non-steroidal anti-inflammatory drugs (NSAIDs), fluorescent probes, and ER-targeting moieties. Through screening the library in cancer cells, we identified a promising compound: an ibuprofen derivative conjugated with a dansyl group as a dual fluorescence tag and ER-targeting moiety. This ibuprofen derivative successfully localized into the ER of HCT-116 colon cancer cells within 3 h, induced ER stress by upregulating key stress markers such as CHOP, GRP94, IRE-1α, PERK, and Cas-12, while simultaneously inhibiting Cox-2. The resulting ER stress triggered autophagy by upregulating Beclin and LC3-II/LC3-I as autophagy markers, followed by apoptosis, culminating in significant cancer cell death, particularly when combined with bafilomycin A, 10-hydroxycamptothecin and obatoclax. This NSAID-based ER stress inducer provides a powerful tool for exploring the chemical biology of NSAIDs in the ER and holds great potential for advancing ER-targeted cancer therapies in combination with other anti-cancer drugs.

Acetaminophen induces mitochondrial apoptosis through proteasome dysfunctions

Acetaminophen is a known antipyretic and non-opioid analgesic for mild pain and fever. Numerous studies uncover their hidden chemotherapeutics applications, including chronic cancer pain management. Acetaminophen also represents an anti-proliferative effect in some cancer cells. Few studies also suggest that the use of Acetaminophen can trigger apoptosis and impede cellular growth. However, Acetaminophen's molecular potential and precise mechanism against improper cellular proliferation and use as an effective anti-proliferative agent still need to be better understood. Here, our current findings show that Acetaminophen induces proteasomal dysfunctions, resulting in aberrant protein accumulation and mitochondrial abnormalities, and consequently induces cell apoptosis. We observed that the Acetaminophen treatment leads to improper aggregation of ubiquitylated expanded polyglutamine proteins, which may be due to the dysfunctions of proteasome activities. Our in-silico analysis suggests the interaction of Acetaminophen and proteasome. Furthermore, we demonstrated the accumulation of proteasome substrates and the depletion of proteasome activities after treating Acetaminophen in cells. Acetaminophen induces proteasome dysfunctions and mitochondrial abnormalities, leading to pro-apoptotic morphological changes and apoptosis successively. These results suggest that Acetaminophen can induce cell death and may retain a promising anti-proliferative effect. These observations can open new possible molecular strategies in the near future for developing and designing specific and effective proteasome inhibitors, which can be helpful in conjugation with other anti-tumor drugs for their better efficiency.

Celecoxib and sulindac sulfide elicit anticancer effects on PIK3CA-mutated head and neck cancer cells through endoplasmic reticulum stress, reactive oxygen species, and mitochondrial dysfunction

Gain-of-function mutation in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) catalytic subunit alpha gene (PIK3CA) is a significant factor in head and neck cancer (HNC). Patients with HNC harboring PIK3CA mutations receive therapeutic benefits from the use of non-steroidal anti-inflammatory drugs (NSAIDs). However, the molecular mechanisms underlying these effects remain unknown. Here, we examined the Detroit562 and FaDu cell lines as HNC models with and without a hyperactive PIK3CA mutation (H1047R), respectively, regarding their possible distinct responses to the NSAIDs celecoxib and sulindac sulfide (SUS). Detroit562 cells exhibited relatively high PI3K/Akt pathway-dependent cyclooxygenase-2 (COX-2) expression, associated with cell proliferation. Celecoxib treatment restricted cell proliferation and upregulated endoplasmic reticulum (ER) stress-related markers, including GRP78, C/EBP-homologous protein, activating transcription factor 4, death receptor 5, and reactive oxygen species (ROS). These effects were much stronger in Detroit562 cells than in FaDu cells and were largely COX-2-independent. SUS treatment yielded similar results. Salubrinal (an ER stress inhibitor) and N-acetyl-L-cysteine (a ROS scavenger) prevented NSAID-induced ROS generation and ER stress, respectively, indicating crosstalk between ER and oxidative stress. In addition, celecoxib and/or SUS elevated cleaved caspase-3 levels, Bcl-2-associated X protein/Bcl-2-interacting mediator of cell death expression, and mitochondrial damage, which was more pronounced in Detroit562 than in FaDu cells. Salubrinal and N-acetyl-L-cysteine attenuated celecoxib-induced mitochondrial dysfunction. Collectively, our results suggest that celecoxib and SUS efficiently suppress activating PIK3CA mutation-harboring HNC progression by inducing ER and oxidative stress and mitochondrial dysfunction, leading to apoptotic cell death, further supporting NSAID treatment as a useful strategy for oncogenic PIK3CA-mutated HNC therapy.

Unraveling the Connection: Pain and Endoplasmic Reticulum Stress

Pain is a complex and multifaceted experience. Recent research has increasingly focused on the role of endoplasmic reticulum (ER) stress in the induction and modulation of pain. The ER is an essential organelle for cells and plays a key role in protein folding and calcium dynamics. Various pathological conditions, such as ischemia, hypoxia, toxic substances, and increased protein production, may disturb protein folding, causing an increase in misfolding proteins in the ER. Such an overload of the folding process leads to ER stress and causes the unfolded protein response (UPR), which increases folding capacity in the ER. Uncompensated ER stress impairs intracellular signaling and cell function, resulting in various diseases, such as diabetes and degenerative neurological diseases. ER stress may be a critical universal mechanism underlying human diseases. Pain sensations involve the central as well as peripheral nervous systems. Several preclinical studies indicate that ER stress in the nervous system is enhanced in various painful states, especially in neuropathic pain conditions. The purpose of this narrative review is to uncover the intricate relationship between ER stress and pain, exploring molecular pathways, implications for various pain conditions, and potential therapeutic strategies.

Fasting potentiates diclofenac-induced liver injury via inductions of oxidative/endoplasmic reticulum stresses and apoptosis, and inhibition of autophagy by depleting hepatic glutathione in mice

Diclofenac, a widely used non-steroidal anti-inflammatory drug, can cause liver damage via its metabolic activation by hepatic CYP450s and UGT2B7. Fasting can affect drug-induced liver injury by modulating the hepatic metabolism, but its influence on diclofenac hepatotoxicity is unknown. Thus, we investigated diclofenac-induced liver damage after fasting in mice, and the cellular events were examined. Male ICR mice fasted for 16 h showed the elevation of CYP3A11, but the decreases of UGT2B7, glutathione (GSH), and GSH S-transferase-μ/-π levels in the livers. Diclofenac (200 mg/kg) injection into the mice after 16-h fasting caused more significant liver damage compared to that in the diclofenac-treated fed mice, as shown by the higher serum ALT and AST activities. Diclofenac-promoted hepatic oxidative stress (oxidized proteins, 4-hydroxynonenal, and malondialdehyde), endoplasmic reticulum (ER) stress (BiP, ATF6, and CHOP), and apoptosis (cleaved caspase-3 and cleaved PARP) were enhanced by fasting. Autophagic degradation was inhibited in the diclofenac-treated fasting mice compared to that of the corresponding fed mice. The results suggest that fasting can make the liver more susceptible to diclofenac toxicity by lowering GSH-mediated detoxification; increased oxidative/ER stresses and apoptosis and suppressed autophagic degradation may be the cellular mechanisms of the aggravated diclofenac hepatotoxicity under fasting conditions.

Integrated analysis of gut metabolome, microbiome, and exfoliome data in an equine model of intestinal injury

BACKGROUND

The equine gastrointestinal (GI) microbiome has been described in the context of various diseases. The observed changes, however, have not been linked to host function and therefore it remains unclear how specific changes in the microbiome alter cellular and molecular pathways within the GI tract. Further, non-invasive techniques to examine the host gene expression profile of the GI mucosa have been described in horses but not evaluated in response to interventions. Therefore, the objectives of our study were to (1) profile gene expression and metabolomic changes in an equine model of non-steroidal anti-inflammatory drug (NSAID)-induced intestinal inflammation and (2) apply computational data integration methods to examine host-microbiota interactions.

METHODS

Twenty horses were randomly assigned to 1 of 2 groups (n = 10): control (placebo paste) or NSAID (phenylbutazone 4.4 mg/kg orally once daily for 9 days). Fecal samples were collected on days 0 and 10 and analyzed with respect to microbiota (16S rDNA gene sequencing), metabolomic (untargeted metabolites), and host exfoliated cell transcriptomic (exfoliome) changes. Data were analyzed and integrated using a variety of computational techniques, and underlying regulatory mechanisms were inferred from features that were commonly identified by all computational approaches.

RESULTS

Phenylbutazone induced alterations in the microbiota, metabolome, and host transcriptome. Data integration identified correlation of specific bacterial genera with expression of several genes and metabolites that were linked to oxidative stress. Concomitant microbiota and metabolite changes resulted in the initiation of endoplasmic reticulum stress and unfolded protein response within the intestinal mucosa.

CONCLUSIONS

Results of integrative analysis identified an important role for oxidative stress, and subsequent cell signaling responses, in a large animal model of GI inflammation. The computational approaches for combining non-invasive platforms for unbiased assessment of host GI responses (e.g., exfoliomics) with metabolomic and microbiota changes have broad application for the field of gastroenterology. Video Abstract.

Cinchophen induces RPA1 related DNA damage and apoptosis to impair ENS development of zebrafish

Nonsteroidal anti-inflammatory drugs (NSAIDs) have become contaminants widely distributed in the environment due to improper disposal and discharge. Previous study has found several components might involve in impairing enteric nervous system (ENS) development of zebrafish, including NSAIDs cinchophen. Deficient ENS development in fetal could lead to Hirschsprung disease (HSCR), a congenital neurocristopathy characterized by absence of enteric neurons in hindgut. However, the intrinsic mechanism of neurotoxicity of cinchophen is unclear. We confirmed that cinchophen could impair ENS development of zebrafish and transcriptome sequencing revealed that disfunction of Replication protein A1 (RPA1), which is involved in DNA replication and repairment, might be relevant to the neurotoxicity effects induced by cinchophen. Based on previous data of single cell RNA sequencing (scRNA-seq) of zebrafish gut cells, we observed that rpa1 mainly expressed in proliferating, differentiating ENS cells and neural crest progenitors. Interestingly, cinchophen induced apoptosis and impaired proliferation. Furthermore, cinchophen caused DNA damage and abnormal activation of ataxia telangiectasia mutated/ Rad3 related (ATM/ATR) and checkpoint kinase 2 (CHK2). Finally, molecular docking indicated cinchophen could bind and antagonize RPA1 more effectively. Our study might provide a better understanding and draw more attention to the role of environmental factors in the pathogenesis of HSCR. And the mechanism of cinchophen neurotoxicity would give theoretical guidance for clinical pharmacy.

A dual role of lysophosphatidic acid type 2 receptor (LPAR2) in nonsteroidal anti-inflammatory drug-induced mouse enteropathy

Lysophosphatidic acid (LPA) is a bioactive phospholipid mediator that has been found to ameliorate nonsteroidal anti-inflammatory drug (NSAID)-induced gastric injury by acting on lysophosphatidic acid type 2 receptor (LPAR2). In this study, we investigated whether LPAR2 signaling was implicated in the development of NSAID-induced small intestinal injury (enteropathy), another major complication of NSAID use. Wild-type (WT) and Lpar2 deficient (Lpar2-/-) mice were treated with a single, large dose (20 or 30 mg/kg, i.g.) of indomethacin (IND). The mice were euthanized at 6 or 24 h after IND treatment. We showed that IND-induced mucosal enteropathy and neutrophil recruitment occurred much earlier (at 6 h after IND treatment) in Lpar2-/- mice compared to WT mice, but the tissue levels of inflammatory mediators (IL-1β, TNF-α, inducible COX-2, CAMP) remained at much lower levels. Administration of a selective LPAR2 agonist DBIBB (1, 10 mg/kg, i.g., twice at 24 h and 30 min before IND treatment) dose-dependently reduced mucosal injury and neutrophil activation in enteropathy, but it also enhanced IND-induced elevation of several proinflammatory chemokines and cytokines. By assessing caspase-3 activation, we found significantly increased intestinal apoptosis in IND-treated Lpar2-/- mice, but it was attenuated after DBIBB administration, especially in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice. Finally, we showed that IND treatment reduced the plasma activity and expression of autotaxin (ATX), the main LPA-producing enzyme, and also reduced the intestinal expression of Lpar2 mRNA, which preceded the development of mucosal damage. We conclude that LPAR2 has a dual role in NSAID enteropathy, as it contributes to the maintenance of mucosal integrity after NSAID exposure, but also orchestrates the inflammatory responses associated with ulceration. Our study suggests that IND-induced inhibition of the ATX-LPAR2 axis is an early event in the pathogenesis of enteropathy.

Meroterpenoids with divers' rings systems from Phyllosticta capitalensis and their anti-inflammatory activity

Four undescribed sesquiterpene-shikimates (1-4), eight undescribed monoterpene-shikimates (5-12), together with two known ones were isolated and identified from the 95% ethanol extract of the plant endophytic fungus Phyllosticta capitalensis cultured in rice medium. Capitalensis A (1) was identified as the first sesquiterpene-shikimate-conjugated spirocyclic meroterpenoid degradation product, while capitalensis B (2) is a sesquiterpene-shikimate-conjugated spirocyclic meroterpenoid with a unique D-ring formed by a C-2-O-C-9' connection. The structures of these previously undescribed compounds were elucidated by multiple techniques, including IR, HR-ESI-MS, and NMR analysis. Furthermore, their absolute configurations were established through the comprehensive approach that involved the calculations of ECD spectra, optical rotation values, and single-crystal X-ray analysis. Moreover, the anti-inflammatory activity of all isolated compounds was evaluated using a lipopolysaccharide (LPS)-induced inflammation model in BV2 microglial cells. Meanwhile, these compounds exhibited activity in inhibiting NO production. Four compounds, capitalensis C (3), capitalensis D (4), 15-hydroxyl tricycloalternarene 5b (13) and guignarenone A (14) showed strong inhibitory effects with IC50 values of 21.6 ± 1.33, 12.2 ± 1.08, 18.6 ± 1.27, and 15.8 ± 1.20 μM, respectively. In addition, the structure-activity relationship of the anti-inflammatory activity of the compounds was discussed.

Stress-mediated aggregation of disease-associated proteins in amyloid bodies

The formation of protein aggregates is a hallmark of many neurodegenerative diseases and systemic amyloidoses. These disorders are associated with the fibrillation of a variety of proteins/peptides, which ultimately leads to cell toxicity and tissue damage. Understanding how amyloid aggregation occurs and developing compounds that impair this process is a major challenge in the health science community. Here, we demonstrate that pathogenic proteins associated with Alzheimer's disease, diabetes, AL/AA amyloidosis, and amyotrophic lateral sclerosis can aggregate within stress-inducible physiological amyloid-based structures, termed amyloid bodies (A-bodies). Using a limited collection of small molecule inhibitors, we found that diclofenac could repress amyloid aggregation of the β-amyloid (1-42) in a cellular setting, despite having no effect in the classic Thioflavin T (ThT) in vitro fibrillation assay. Mapping the mechanism of the diclofenac-mediated repression indicated that dysregulation of cyclooxygenases and the prostaglandin synthesis pathway was potentially responsible for this effect. Together, this work suggests that the A-body machinery may be linked to a subset of pathological amyloidosis, and highlights the utility of this model system in the identification of new small molecules that could treat these debilitating diseases.

Regulatory lipid vicinal diols counteract the biological activity of epoxy fatty acids and can act as biomarkers and mechanisms for disease progression

Polyunsaturated fatty acids (PUFAs) are essential fatty acids required for human health and are obtained primarily from food or synthesized in the body by highly regulated processes. The metabolites of these lipids, formed largely through the action of cyclooxygenase, lipoxygenase, or cytochrome P450 (CYP450) enzymes, are responsible for multiple biological functions including inflammation, tissue repair, cell proliferation, blood vessel permeability, and immune cell behavior. The role of these regulatory lipids in disease has been well studied since their discovery as druggable targets; however, the metabolites generated downstream of these pathways have only recently gained attention for regulating biology. Specifically, the biological activity of lipid vicinal diols formed from the metabolism of CYP450-generated epoxy fatty acids (EpFA) by epoxide hydrolases were previously thought to have little biological activity but increasingly are recognized as promoting inflammation and brown fat adipogenesis, and exciting neurons through the regulation of ion channel activity at low concentrations. These metabolites also appear to balance the action of the EpFA precursor. For example, EpFA demonstrate the ability to resolve inflammation and reduce pain, while some lipid diols, through opposing mechanisms, promote inflammation and pain. This review describes recent studies that highlight the role of regulatory lipids, focusing on the balance between EpFA and their diol metabolites in promoting or resolving disease.

Risk of Gastrointestinal Bleeding with Concurrent Use of NSAID and SSRI: A Systematic Review and Network Meta-Analysis

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used over-the-counter medications that can increase the risk of gastrointestinal (GI) bleeding through antiplatelet effects and loss of GI protection. Selective serotonin reuptake inhibitors (SSRIs), commonly used for mental and behavioral health, are another group of medications that can cause platelet dysfunction. Previous literature has shown a possible increased risk of GI bleeding with concurrent use of SSRIs and NSAIDs. We performed a network meta-analysis comparing NSAIDs, SSRIs, and combined SSRI/NSAIDs to assess the risk of GI bleeding.

METHODS

The following databases were searched: MEDLINE, Embase, Web of Science Core Collection, SciELO, KCI, and Cochrane database. All comparative studies, i.e., case-control, cohort, and randomized controlled trials were included. Direct and network meta-analysis was conducted using DerSimonian-Laird approach and random effect. For binary outcomes, odds ratio (OR) with 95% confidence interval (CI) and p value were calculated.

RESULTS

After a comprehensive search through November 10th, 2021, 15 studies with 82,605 patients were identified. 11 studies reported higher rates of GI bleeds in SSRI/NSAID than SSRI users (36.9% vs 22.8%, OR 2.14, 95% CI 1.52-3.02, p < 0.001, I² = 86.1%). 10 studies compared SSRI/NSAID to NSAID users with higher rates of bleeds in SSRI/NSAID group (40.9% vs 34.2%, OR 1.49, 95% CI 1.20-1.84, p < 0.001, I² = 68.8%). The results were consistent using network meta-analysis as well.

CONCLUSION

Given higher risk of bleeding with concurrent NSAIDs and SSRIs, prescribers should exercise caution when administering NSAIDs and SSRIs concurrently especially in patients with higher risks of GI bleeding.

Synthesis and Investigation of Anti-Inflammatory Activity of New Thiourea Derivatives of Naproxen

The aim of the study was a synthesis and investigation of the dose-dependent anti-inflammatory effect of new thiourea derivatives of naproxen with selected aromatic amines and esters of aromatic amino acids. The results of the in vivo study indicate that derivatives of m-anisidine (4) and N-methyl tryptophan methyl ester (7) showed the most potent anti-inflammatory activity four hours after injection of carrageenan, with the percentage of inhibition of 54.01% and 54.12%, respectively. In vitro assays of COX-2 inhibition demonstrated that none of the tested compounds achieved 50% inhibition at concentrations lower than 100 µM. On the other hand, the aromatic amine derivatives (1-5) accomplished significant inhibition of 5-LOX, and the lowest IC₅₀ value was observed for compound 4 (0.30 μM). High anti-edematous activity of compound 4 in the rat paw edema model, together with potent inhibition of 5-LOX, highlight this compound as a promising anti-inflammatory agent.

Role of cyclooxygenase pathways in bowel fibrotic remodelling in a murine model of experimental colitis

OBJECTIVE

Gut fibrosis occurs under chronic inflammation. This study examined the effects of different cyclooxygenase (COX) inhibitors on fibrosis in the inflamed colon.

METHODS

Colitis was induced by 2,4-dinitrobenzenesulfonic acid (DNBS) in albino male Sprague-Dawley rats. After 6, 12 and 18 days, macroscopic and microscopic damage, collagen and elastic fibre content were examined. At day 6, pro-fibrotic factors (collagen I and III, hydroxyproline, fibronectin, matrix metalloproteinase-2 and -9), transforming growth factor-beta (TGF-β) signalling [TGF-β, Ras homolog gene family member A (RhoA), phosphorylated small mother against decapentaplegic (pSMAD)-2 and -6] and peristalsis were assessed, and the effects of indomethacin, SC-560 or celecoxib were tested.

KEY FINDINGS

Six days after DNBS administration, significant histopathological signs of fibrotic remodelling were observed in rats. At day 6, pro-fibrotic factors were up-regulated and colonic peristalsis was altered. COX inhibitors reversed the histochemical, molecular and functional changes in the fibrotic colon. COX inhibition reduced TGF-β expression, SMAD2 phosphorylation and RhoA, and increased SMAD6 expression.

CONCLUSIONS

Colonic fibrosis is associated with altered bowel motility and induction of profibrotic factors driven by TGF-β signalling. COX-1 and COX-2 inhibition counteracts this fibrotic remodelling by the modulation of TGF-β/SMAD signalling, mainly via SMAD6 induction and reduction in SMAD2 phosphorylation.

The Role of COX-2 and PGE2 in the Regulation of Immunomodulation and Other Functions of Mesenchymal Stromal Cells

The ability of MSCs to modulate the inflammatory environment is well recognized, but understanding the molecular mechanisms responsible for these properties is still far from complete. Prostaglandin E2 (PGE2), a product of the cyclooxygenase 2 (COX-2) pathway, is indicated as one of the key mediators in the immunomodulatory effect of MSCs. Due to the pleiotropic effect of this molecule, determining its role in particular intercellular interactions and aspects of cell functioning is very difficult. In this article, the authors attempt to summarize the previous observations regarding the role of PGE2 and COX-2 in the immunomodulatory properties and other vital functions of MSCs. So far, the most consistent results relate to the inhibitory effect of MSC-derived PGE2 on the early maturation of dendritic cells, suppressive effect on the proliferation of activated lymphocytes, and stimulatory effect on the differentiation of macrophages into M2 phenotype. Additionally, COX-2/PGE2 plays an important role in maintaining the basic life functions of MSCs, such as the ability to proliferate, migrate and differentiate, and it also positively affects the formation of niches that are conducive to both hematopoiesis and carcinogenesis.

Non-steroidal anti-inflammatory drugs (NSAIDs): A current insight into its molecular mechanism eliciting organ toxicities

Non-steroidal anti-inflammatory drugs (NSAIDs) are a class of medications that are routinely been used across the world. Their analgesic, anti-inflammatory, and antipyretic effects have all been well-documented. Moreover, they are been deliberated to have a protective role against various critical diseases such as cancer and cardiovascular diseases. However, the data presented by numerous studies in past have signified the adverse effects of NSAIDs due to overdosing on various systems such as cardiovascular, gastrointestinal, hepatic, renal, neural, etc. Despite substantial studies representing the mechanism behind the clinical risk of NSAIDs, there are very few reviews that have collated comprehensive records of various toxicities caused by overdosing on NSAIDs. As a result, we have presented a comprehensive overview of existing information on NSAIDs in this review. In addition to that, we have concentrated on presenting our understanding of various organ-based toxicities caused due to NSAID's prolonged use/overdosage.

Effects of the anti-inflammatory drug celecoxib on cell death signaling in human colon cancer

The anti-inflammatory drug celecoxib, the only inhibitor of cyclooxygenase-2 (COX-2) with anticancer activity, is used to treat rheumatoid arthritis and can cause endoplasmic reticulum (ER) stress by inhibiting sarco/ER Ca^{2 +}-ATPase activity in cancer cells. This study aimed to investigate the correlation between celecoxib-induced ER stress and the effects of celecoxib against cell death signaling. Treatment of human colon cancer HCT116 cells with celecoxib reduced their viability and resulted in a loss of mitochondrial membrane potential ([Formula: see text]). Additionally, celecoxib treatment reduced the expression of genes involved in mitochondrial biogenesis and metabolism such as mitochondrial transcription factor A (TFAM) and uncoupling protein 2 (UCP2). Furthermore, celecoxib reduced transmembrane protein 117 (TMEM117), and RNAi-mediated knockdown of TMEM117 reduced TFAM and UCP2 expressions. These results suggest that celecoxib treatment results in the loss of [Formula: see text] by reducing TMEM117 expression and provide insights for the development of novel drugs through TMEM117 expression.

Characterization of dissolved black carbon and its binding behaviors to ceftazidime and diclofenac pharmaceuticals: Employing the molecular weight fractionation

As the ubiquitous component of the aquatic environment, dissolved organic matter (DOM) readily bind with residual pharmaceutical contaminants (PCs) and influence their environmental behaviors. However, the binding mechanisms between dissolved black carbon (DBC), a vital part of the natural DOM pool, and PCs were poorly researched. In this study, the bulk DBC was divided into four fractions in molecular weight (MW) via an ultrafiltration system, and the properties of DBC and their binding interaction with two kinds of typical PCs (ceftazidime (CAZ) and diclofenac (DCF)) were explored concretely. The results showed that low MW component was the main contributor to bulk DBC, and the aromaticity increased with the increase of MW. The categories of chemical structures and fluorescent substances in different MW DBC were similar. Multispectral techniques showed that the oxygen-enriched compounds in DBC had the higher affinity to CAZ/DCF. The -NH-, -COOH, -NH₂ groups in CAZ molecules appeared to form the hydrogen bond with DBC. Fluorescence quenching experiments were analyzed, and the binding mechanisms were specifically expounded from the thermodynamic perspective. The fluorophore of fulvic acid-like compounds (FA) were quenched by both static and dynamic quenching mechanisms, while only static quenching occurred for humic acid-like compounds (HA). For bulk DBC, the hydrogen bond and van der Waals force were the major forces in the HA-CAZ system, while the hydrophobic force made the primary contribution to the HA-DCF system, which might be ascribed to the higher hydrophobic nature of DCF. Notably, with the increase of HA MW, the main binding mode of HA-CAZ/DCF changed from hydrophobic force to hydrogen bond and van der Waals force gradually, which also directly proved that various noncovalent interactions co-driven the binding processes. Our findings are beneficial to better assess the fate of DBC and PCs and the corresponding complexes in the aquatic environment.

Risk of serious adverse events associated with non-steroidal anti-inflammatory drugs in orthopaedic surgery. A protocol for a systematic review

BACKGROUND

Postoperative pain is a common condition following orthopaedic surgeries and causes prolonged hospitalisation, delayed rehabilitation and hamper the quality of life. Non-steroidal anti-inflammatory drugs (NSAIDs) are effective analgesics and anti-inflammatory mediators in the treatment of postoperative pain. The association of NSAIDs with serious adverse events may however keep some clinicians and clinical decision makers from using NSAIDs perioperatively. The evidence regarding the risks of serious adverse events following perioperative use of NSAIDs in orthopaedic surgery is sparse and needs to be assessed in a systematic review. This is a protocol for a systematic review that aims to identify the risks of serious adverse events from perioperative use of NSAIDs in orthopaedic patients.

METHODS

Our methodology is based on the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols and the eight-step assessment procedure suggested by Jakobsen and colleagues. We wish to assess if NSAIDs versus placebo, usual care or no intervention, will influence the risks of serious adverse events in patients undergoing orthopaedic surgery. We will include all randomised trials assessing the use of NSAIDs perioperatively. To identify trials we will search the Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Cochrane Central Register, Science Citation Index Expanded on Web of Science and BIOSIS. Two authors will screen the literature and extract data. We will use the 'Risk of Bias 2 tool' to assess trials. Extracted data will be analysed using RStudio and Trial Sequential Analysis. We will create a 'Summary of Findings' table in which we will present our primary and secondary outcomes. We will assess the quality of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

DISCUSSION

This systematic review can potentially aid clinicians and clinical decision makers in the use of NSAIDs for treatment of postoperative pain following orthopaedic surgeries.

Neuromodulation Applied to Diseases: The Case of HRV Biofeedback

The vagus or “wandering” nerve is the main branch of the parasympathetic nervous system (PNS), innervating most internal organs crucial for health. Activity of the vagus nerve can be non-invasively indexed by heart-rate variability parameters (HRV). Specific HRV parameters predict less all-cause mortality, lower risk of and better prognosis after myocardial infarctions, and better survival in cancer. A non-invasive manner for self-activating the vagus is achieved by performing a slow-paced breathing technique while receiving visual feedback of one’s HRV, called HRV-biofeedback (HRV-B). This article narratively reviews the biological mechanisms underlying the role of vagal activity and vagally mediated HRV in hypertension, diabetes, coronary heart disease (CHD), cancer, pain, and dementia. After searching the literature for HRV-B intervention studies in each condition, we report the effects of HRV-B on clinical outcomes in these health conditions, while evaluating the methodological quality of these studies. Generally, the levels of evidence for the benefits of HRV-B is high in CHD, pain, and hypertension, moderate in cancer, and poor in diabetes and dementia. Limitations and future research directions are discussed.

Indomethacin-induced oxidative stress enhances death receptor 5 signaling and sensitizes tumor cells to adoptive T-cell therapy

BACKGROUND

Adoptive cell therapy (ACT) using genetically modified T cells has evolved into a promising treatment option for patients with cancer. However, even for the best-studied and clinically validated CD19-targeted chimeric antigen receptor (CAR) T-cell therapy, many patients face the challenge of lack of response or occurrence of relapse. There is increasing need to improve the efficacy of ACT so that durable, curative outcomes can be achieved in a broad patient population.

METHODS

Here, we investigated the impact of indomethacin (indo), a non-steroidal anti-inflammatory drug (NSAID), on the efficacy of ACT in multiple preclinical models. Mice with established B-cell lymphoma received various combinations of preconditioning chemotherapy, infusion of suboptimal dose of tumor-reactive T cells, and indo administration. Donor T cells used in the ACT models included CD4+ T cells expressing a tumor-specific T cell receptor (TCR) and T cells engineered to express CD19CAR. Mice were monitored for tumor growth and survival. The effects of indo on donor T cell phenotype and function were evaluated. The molecular mechanisms by which indo may influence the outcome of ACT were investigated.

RESULTS

ACT coupled with indo administration led to improved tumor growth control and prolonged mouse survival. Indo did not affect the activation status and tumor infiltration of the donor T cells. Moreover, the beneficial effect of indo in ACT did not rely on its inhibitory effect on the immunosuppressive cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) axis. Instead, indo-induced oxidative stress boosted the expression of death receptor 5 (DR5) in tumor cells, rendering them susceptible to donor T cells expressing TNF-related apoptosis-inducing ligand (TRAIL). Furthermore, the ACT-potentiating effect of indo was diminished against DR5-deficient tumors, but was amplified by donor T cells engineered to overexpress TRAIL.

CONCLUSION

Our results demonstrate that the pro-oxidative property of indo can be exploited to enhance death receptor signaling in cancer cells, providing rationale for combining indo with genetically modified T cells to intensify tumor cell killing through the TRAIL-DR5 axis. These findings implicate indo administration, and potentially similar use of other NSAIDs, as a readily applicable and cost-effective approach to augment the efficacy of ACT.

Diclofenac Diminished the Unfolded Protein Response (UPR) Induced by Tunicamycin in Human Endothelial Cells

Diclofenac belongs to the class of nonsteroidal anti-inflammatory drugs (NSAIDs), which are amongst the most frequently prescribed drugs to treat fever, pain and inflammation. Despite the presence of NSAIDs on the pharmaceutical market for several decades, epidemiological studies have shown new clinical applications of NSAIDs, and new mechanisms of their action were discovered. The unfolded protein response (UPR) activated under endoplasmic reticulum (ER) stress is involved in the pathophysiology of many diseases and may become a drug target, therefore, the study evaluated the effects of diclofenac on the tunicamycin-induced UPR pathways in endothelial cells. RT PCR analysis showed that diclofenac significantly inhibited activation of ER stress-responsive genes, i.e., CHOP/DITT3, GRP78/HSPA5 and DNAJB9. Additionally, the drug diminished the significant upregulation and release of the GRP78 protein, as evaluated using the ELISA assay, which was likely to be involved in the mechanism of the UPR activation resulting in apoptosis induction in endothelial cells. These results suggest the value of diclofenac as a factor capable of restoring the ER homeostasis in endothelial cells by diminishing the UPR.

Galactosylated Prodrugs: A Strategy to Improve the Profile of Nonsteroidal Anti-Inflammatory Drugs

Carbohydrates are one of the most abundant and important classes of biomolecules. The variety in their structures makes them valuable carriers that can improve the pharmaceutical phase, pharmacokinetics and pharmacodynamics of well-known drugs. D-galactose is a simple, naturally occurring monosaccharide sugar that has been extensively studied for use as a carrier and has proven to be valuable in this role. With the aim of validating the galactose-prodrug approach, we have investigated the galactosylated prodrugs ibuprofen, ketoprofen, flurbiprofen and indomethacin, which we have named IbuGAL, OkyGAL, FluGAL and IndoGAL, respectively. Their physicochemical profiles in terms of lipophilicity, solubility and chemical stability have been evaluated at different physiological pH values, as have human serum stability and serum protein binding. Ex vivo intestinal permeation experiments were performed to provide preliminary insights into the oral bioavailability of the galactosylated prodrugs. Finally, their anti-inflammatory, analgesic and ulcerogenic activities were investigated in vivo in mice after oral treatment. The present results, taken together with those of previous studies, undoubtedly validate the galactosylated prodrug strategy as a problem-solving technique that can overcome the disadvantages of NSAIDs.

Astragaloside IV protects against C/EBP homologous protein-mediated apoptosis in oxidized low-density lipoprotein-treated macrophages by promoting autophagy

Astragaloside Ⅳ (AS-Ⅳ) is one of the main active components extracted from Astragalus membranaceus that exerts an antiatherosclerotic effect. Our study explored the underlying anti-apoptotic effects and the mechanisms of action of AS-Ⅳ in oxidized low-density lipoprotein (oxLDL)-stimulated macrophages and in vulnerable plaques. The results showed that AS-Ⅳ lowered the oxLDL-induced lipid content and reversed the oxLDL-induced reduction in cell viability and elevation in lactate dehydrogenase (LDH) leakage and apoptosis in RAW264.7 macrophages, similar to the effects of 4-phenylbutyric acid (PBA, an ER stress inhibitor). In addition, consistent with the effect exerted by PBA, AS-Ⅳ inhibited oxLDL-triggered ER stress activation by decreasing the level of inositol-requiring enzyme1 phosphorylation and transcription factor 6 nuclear translocation and upregulating the protein and mRNA expression of glucose-regulated protein 78 (GPR78) and C/EBP homologous protein (CHOP). As expected, autophagy activation was induced by AS-IV, evidenced by increased expression of microtubule-associated protein 1 light chain 3-Ⅱ (LC3-Ⅱ), autophagy-related gene 5, and beclin-1 in macrophages. Furthermore, after pretreatment with 3-methyladenine and beclin-1 small interfering RNA, the inhibitory role played by AS-Ⅳ in oxLDL-induced ER stress-CHOP-mediated macrophage apoptosis was weakened, while its inhibitory effect was further enhanced by rapamycin pretreatment. Moreover, administration of AS-Ⅳ or rapamycin to Apoe^-/- mice upregulated LC3-Ⅱ expression and collagen content but decreased CHOP expression, macrophage apoptosis, and lipid areas. Overall, by promoting autophagy, AS-Ⅳ effectively protects macrophages from oxLDL-induced apoptosis mediated by ER stress-CHOP, which may reinforce the stability of atherosclerotic plaques.

Oxidative stress in cancer therapy: Friend or enemy?

Excessive cellular oxidative stress is widely perceived as a key factor in pathophysiological conditions and cancer development. Healthy cells use several mechanisms to maintain intracellular levels of reactive oxygen species (ROS) and overall redox homeostasis to avoid damage to DNA, proteins, and lipids. Cancer cells, in contrast, exhibit elevated ROS levels and upregulated protective antioxidant pathways. Counterintuitively, such elevated oxidative stress and enhanced antioxidant defence mechanisms in cancer cells provide a therapeutic opportunity for the development of drugs with different anticancer mechanisms of action (MoA). In this review, oxidative stress and the role of ROS in cells are described. The tumour-suppressive and tumour-promotive functions of ROS are discussed to compare these two different therapeutic strategies (increasing or decreasing ROS to fight cancer). Clinically approved drugs with demonstrated oxidative stress anticancer MoAs are highlighted before describing examples of metal-based anticancer drug candidates causing oxidative stress in cancer cells via novel MoAs.

Roles of EP Receptors in the Regulation of Fluid Balance and Blood Pressure

Prostaglandin E2 (PGE2) is an important prostanoid expressing throughout the kidney and cardiovascular system. Despite the diverse effects on fluid metabolism and blood pressure, PGE2 is implicated in sustaining volume and hemodynamics homeostasis. PGE2 works through four distinct E-prostanoid (EP) receptors which are G protein-coupled receptors. To date, pharmacological specific antagonists and agonists of all four subtypes of EP receptors and genetic targeting knockout mice for each subtype have helped in uncoupling the diverse functions of PGE2 and discriminating the respective characteristics of each receptor. In this review, we summarized the functions of individual EP receptor subtypes in the renal and blood vessels and the molecular mechanism of PGE2-induced fluid metabolism and blood pressure homeostasis.

HiPSC-Derived Hepatocyte-like Cells Can Be Used as a Model for Transcriptomics-Based Study of Chemical Toxicity

Traditional toxicity risk assessment approaches have until recently focussed mainly on histochemical readouts for cell death. Modern toxicology methods attempt to deduce a mechanistic understanding of pathways involved in the development of toxicity, by using transcriptomics and other big data-driven methods such as high-content screening. Here, we used a recently described optimised method to differentiate human induced pluripotent stem cells (hiPSCs) to hepatocyte-like cells (HLCs), to assess their potential to classify hepatotoxic and non-hepatotoxic chemicals and their use in mechanistic toxicity studies. The iPSC-HLCs could accurately classify chemicals causing acute hepatocellular injury, and the transcriptomics data on treated HLCs obtained by TempO-Seq technology linked the cytotoxicity to cellular stress pathways, including oxidative stress and unfolded protein response (UPR). Induction of these stress pathways in response to amiodarone, diclofenac, and ibuprofen, was demonstrated to be concentration and time dependent. The transcriptomics data on diclofenac-treated HLCs were found to be more sensitive in detecting differentially expressed genes in response to treatment, as compared to existing datasets of other diclofenac-treated in vitro hepatocyte models. Hence iPSC-HLCs generated by transcription factor overexpression and in metabolically optimised medium appear suitable for chemical toxicity detection as well as mechanistic toxicity studies.

Effect of Quercetin on Injury to Indomethacin-Treated Human Embryonic Kidney 293 Cells

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammation and pain and even to prevent the progression of cardiovascular disease. They have become widely used because of their effectiveness, especially among athletes performing high-intensity training. Indomethacin is used for pain management in sports medicine and is highly effective and versatile. However, several clinical studies have reported that indomethacin induces acute renal damage. In the present study, we determined that indomethacin reduced human embryonic kidney 293 (HEK293) cell viability in a concentration-dependent manner by triggering apoptosis. In addition, we demonstrated the effect of quercetin on indomethacin-treated HEK293 cells by inactivating the caspase-3 and caspase-9 signals. Furthermore, quercetin reduced ROS production and increased mitochondrial membrane potential (ΔΨm) in indomethacin-treated HEK293 cells. Our results indicate that quercetin can interrupt the activated caspase and mitochondrial pathway induced by indomethacin in HEK293 cells and affect apoptotic mRNA expression. Quercetin can protect against indomethacin-induced HEK293 cell apoptosis by regulating abnormal ΔΨm and apoptotic mRNA expression.

Advanced preclinical models for evaluation of drug-induced liver injury - consensus statement by the European Drug-Induced Liver Injury Network [PRO-EURO-DILI-NET]

Drug-induced liver injury (DILI) is a major cause of acute liver failure (ALF) and one of the leading indications for liver transplantation in Western societies. Given the wide use of both prescribed and over the counter drugs, DILI has become a major health issue for which there is a pressing need to find novel and effective therapies. Although significant progress has been made in understanding the molecular mechanisms underlying DILI, our incomplete knowledge of its pathogenesis and inability to predict DILI is largely due to both discordance between human and animal DILI in preclinical drug development and a lack of models that faithfully recapitulate complex pathophysiological features of human DILI. This is exemplified by the hepatotoxicity of acetaminophen (APAP) overdose, a major cause of ALF because of its extensive worldwide use as an analgesic. Despite intensive efforts utilising current animal and in vitro models, the mechanisms involved in the hepatotoxicity of APAP are still not fully understood. In this expert Consensus Statement, which is endorsed by the European Drug-Induced Liver Injury Network, we aim to facilitate and outline clinically impactful discoveries by detailing the requirements for more realistic human-based systems to assess hepatotoxicity and guide future drug safety testing. We present novel insights and discuss major players in APAP pathophysiology, and describe emerging in vitro and in vivo pre-clinical models, as well as advanced imaging and in silico technologies, which may improve prediction of clinical outcomes of DILI.

Targeting Soluble Epoxide Hydrolase and Cyclooxygenases Enhance Joint Pain Control, Stimulate Collagen Synthesis, and Protect Chondrocytes From Cytokine-Induced Apoptosis

Objective: To determine the symptomatic and disease-modifying capabilities of sEH and COX inhibitors during joint inflammation. Methods: Using a blinded, randomized, crossover experimental design, 6 adult healthy horses were injected with lipopolysaccharide (LPS; 3 μg) from E. coli in a radiocarpal joint and concurrently received the non-selective cyclooxygenase (COX) inhibitor phenylbutazone (2 mg/kg), the sEH inhibitor t-TUCB (1 mg/kg) or both (2 mg/kg phenylbutazone and 0.1, 0.3, and 1 mg/kg t-TUCB) intravenously. There were at least 30 days washout between treatments. Joint pain (assessed via inertial sensors and peak vertical forces), synovial fluid concentrations of prostanoids (PGE₂, TxB₂), cytokines (IL-1β, IL-6, TNF-α) and biomarkers of collagen synthesis (CPII) and degradation (C2C) were measured at pre-determined intervals over a 48-h period. The anti-apoptotic effect of COX and sEH inhibitors was determined via ELISA technique in primary equine chondrocytes incubated with TNF-α (10 ng/ml) for 24 h. Apoptosis was also determined in chondrocytes incubated with sEH-generated metabolites. Results: Combined COX and sEH inhibition produced significantly better control of joint pain, prostanoid responses, and collagen synthesis-degradation balance compared to each compound separately. When administered separately, pain control was superior with COX vs. sEH inhibition. Cytokine responses were not different during COX and/or sEH inhibition. In cultured chondrocytes, sEH inhibition alone or combined with COX inhibition, but not COX inhibition alone had significant anti-apoptotic effects. However, sEH-generated metabolites caused concentration-dependent apoptosis. Conclusions: Combined COX and sEH inhibition optimize pain control, attenuate loss of articular cartilage matrix during joint inflammation and cytokine-induced chondrocyte apoptosis.

Challenging inflammatory process at molecular, cellular and in vivo levels via some new pyrazolyl thiazolones

The work reported herein describes the synthesis of a new series of anti-inflammatory pyrazolyl thiazolones. In addition to COX-2/15-LOX inhibition, these hybrids exerted their anti-inflammatory actions through novel mechanisms. The most active compounds possessed COX-2 inhibitory activities comparable to celecoxib (IC₅₀ values of 0.09-0.14 µM) with significant 15-LOX inhibitory activities (IC₅₀s 1.96 to 3.52 µM). Upon investigation of their in vivo anti-inflammatory activities and ulcerogenic profiles, these compounds showed activity patterns equivalent or more superior to diclofenac and/or celecoxib. Intriguingly, the most active compounds were more effective than diclofenac in suppressing monocyte-to-macrophage differentiation and inflammatory cytokine production by activated macrophages, as well as their ability to induce macrophage apoptosis. The latter finding potentially adds a new dimension to the previously reported anti-inflammatory mechanisms of similar compounds. These compounds were effectively docked into COX-2 and 15-LOX active sites. Also, in silico predictions confirmed the appropriateness of these compounds as drug-like candidates.

Assessment of the cytotoxic, genotoxic, and apoptotic potential of flurbiprofen in HeLa and HepG2 cell lines

In the literature, the anticancer potential of flurbiprofen isn't fully understood. In this study, the cytotoxic, genotoxic, and apoptotic effects of flurbiprofen were evaluated in human cervical and liver cancer cells. Cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and it was observed that cytotoxicity increased in a concentration- and time-dependent manner. Genotoxicity was determined using alkaline Comet assay. DNA damage increased in a concentration-dependent manner. Early apoptosis was evaluated using real-time polymerase chain reaction, and it was found that apoptotic gene levels increased while antiapoptotic gene levels decreased. Late apoptosis and cell cycle analyzes were determined using flow cytometry. No evidence of late apoptosis was observed, and no significant arrest was found in the cell cycle. In conclusion, it seems that flurbiprofen has a cytotoxic, genotoxic, and apoptotic effects in both human cancer cell lines. Moreover, the findings indicate that flurbiprofen is effective at the gene level and induces apoptosis with an intracellular pathway.

Non-steroidal anti-inflammatory drugs induce immunogenic cell death in suppressing colorectal tumorigenesis

Use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with reduced risk of colorectal cancer (CRC). However, the mechanism by which NSAIDs suppress colorectal tumorigenesis remains unclear. We previously showed that NSAIDs selectively kill emerging tumor cells via death receptor (DR) signaling and a synthetic lethal interaction mediated by the proapoptotic Bcl-2 family protein BID. In this study, we found NSAIDs induce endoplasmic reticulum (ER) stress to activate DR signaling and BID in tumor suppression. Importantly, our results unveiled an ER stress- and BID-dependent immunogenic effect of NSAIDs, which may be critical for tumor suppression. NSAID treatment induced hallmarks of immunogenic cell death (ICD) in CRC cells and colonic epithelial cells upon loss of APC tumor suppressor, and elevated tumor-infiltrating lymphocytes (TILs) in the polyps of APCMin/+ mice. ER stress inhibition or BID deletion abrogated the antitumor and immunogenic effects of NSAIDs. Furthermore, increased ER stress and TILs were detected in human advanced adenomas from NSAID-treated patients. Together, our results suggest that NSAIDs induce ER stress- and BID-mediated ICD to restore immunosurveillance and suppress colorectal tumor formation.

Oxidative Stress in the Tumor Microenvironment and Its Relevance to Cancer Immunotherapy

Simple Summary

Cancer cells are consistently under oxidative stress, as reflected by elevated basal level of reactive oxygen species (ROS), due to increased metabolism driven by aberrant cell growth. This feature has been exploited to develop therapeutic strategies that control tumor growth by modulating the oxidative stress in tumor cells. This review provides an overview of recent advances in cancer therapies targeting tumor oxidative stress, and highlights the emerging evidence implicating the effectiveness of cancer immunotherapies in intensifying tumor oxidative stress. The promises and challenges of combining ROS-inducing agents with cancer immunotherapy are also discussed.

Abstract

It has been well-established that cancer cells are under constant oxidative stress, as reflected by elevated basal level of reactive oxygen species (ROS), due to increased metabolism driven by aberrant cell growth. Cancer cells can adapt to maintain redox homeostasis through a variety of mechanisms. The prevalent perception about ROS is that they are one of the key drivers promoting tumor initiation, progression, metastasis, and drug resistance. Based on this notion, numerous antioxidants that aim to mitigate tumor oxidative stress have been tested for cancer prevention or treatment, although the effectiveness of this strategy has yet to be established. In recent years, it has been increasingly appreciated that ROS have a complex, multifaceted role in the tumor microenvironment (TME), and that tumor redox can be targeted to amplify oxidative stress inside the tumor to cause tumor destruction. Accumulating evidence indicates that cancer immunotherapies can alter tumor redox to intensify tumor oxidative stress, resulting in ROS-dependent tumor rejection. Herein we review the recent progresses regarding the impact of ROS on cancer cells and various immune cells in the TME, and discuss the emerging ROS-modulating strategies that can be used in combination with cancer immunotherapies to achieve enhanced antitumor effects.

A mechanism of perhexiline's cytotoxicity in hepatic cells involves endoplasmic reticulum stress and p38 signaling pathway

Perhexiline is a coronary vasodilator for angina treatment that was first developed in the 1960s. Perhexiline enjoyed worldwide success before reports of severe side effects, such as hepatotoxicity and neurotoxicity, caused its withdrawal from most of the markets. The underlying mechanism of the cytotoxicity of perhexiline, however, is not yet well understood. Here we demonstrated that perhexiline induced cellular damage in primary human hepatocytes, HepaRG cells and HepG2 cells. Analysis of gene and protein expression levels of endoplasmic reticulum (ER) stress markers showed that perhexiline caused ER stress in primary human hepatocytes and HepG2 cells. The splicing of XBP1 mRNA, a hallmark of ER stress, was observed upon perhexiline treatment. Using Gluc-Fluc-HepG2 cell line, we demonstrated that protein secretion was impaired upon perhexiline treatment, suggesting functional deficits in ER. Inhibition of ER stress using ER inhibitor 4-PBA or salubrinal attenuated the cytotoxicity of perhexiline. Directly knocking down ATF4 using siRNA also partially rescued HepG2 cells upon perhexiline exposure. In addition, inhibition of ER stress using either inhibitors or siRNA transfection attenuated perhexiline-induced increase in caspase 3/7 activity, indicating that ER stress contributed to perhexiline-induced apoptosis. Moreover, perhexiline treatment resulted in activation of p38 and JNK signaling pathways, two branches of MAPK cascade. Pre-treating HepG2 cells with p38 inhibitor SB239063 attenuated perhexiline-induced apoptosis and cell death. The inhibitor also prevented the activation of CHOP and ATF4. Overall, our study demonstrated that ER stress is one important mechanism underlying the hepatotoxicity of perhexiline, and p38 signaling pathway contributes to this process. Our finding shed light on the role of both ER stress and p38 signaling pathway in drug-induced liver injury.

Non-steroidal anti-inflammatory drugs (NSAIDs) and organ damage: A current perspective

Owing to the efficacy in reducing pain and inflammation, non-steroidal anti-inflammatory drugs (NSAIDs) are amongst the most popularly used medicines confirming their position in the WHO's Model List of Essential Medicines. With escalating musculoskeletal complications, as evident from 2016 Global Burden of Disease data, NSAID usage is evidently unavoidable. Apart from analgesic, anti-inflammatory and antipyretic efficacies, NSAIDs are further documented to offer protection against diverse critical disorders including cancer and heart attacks. However, data from multiple placebo-controlled trials and meta-analyses studies alarmingly signify the adverse effects of NSAIDs in gastrointestinal, cardiovascular, hepatic, renal, cerebral and pulmonary complications. Although extensive research has elucidated the mechanisms underlying the clinical hazards of NSAIDs, no review has extensively collated the outcomes on various multiorgan toxicities of these drugs together. In this regard, the present review provides a comprehensive insight of the existing knowledge and recent developments on NSAID-induced organ damage. It precisely encompasses the current understanding of structure, classification and mode of action of NSAIDs while reiterating on the emerging instances of NSAID drug repurposing along with pharmacophore modification aimed at safer usage of NSAIDs where toxic effects are tamed without compromising the clinical benefits. The review does not intend to vilify these 'wonder drugs'; rather provides a careful understanding of their side-effects which would be beneficial in evaluating the risk-benefit threshold while rationally using NSAIDs at safer dose and duration.

CHOP and c-JUN up-regulate the mutant Z α1-antitrypsin, exacerbating its aggregation and liver proteotoxicity

α₁-Antitrypsin (AAT) encoded by the SERPINA1 gene is an acute-phase protein synthesized in the liver and secreted into the circulation. Its primary role is to protect lung tissue by inhibiting neutrophil elastase. The Z allele of SERPINA1 encodes a mutant AAT, named ATZ, that changes the protein structure and leads to its misfolding and polymerization, which cause endoplasmic reticulum (ER) stress and liver disease through a gain-of-function toxic mechanism. Hepatic retention of ATZ results in deficiency of one of the most important circulating proteinase inhibitors and predisposes to early-onset emphysema through a loss-of-function mechanism. The pathogenetic mechanisms underlying the liver disease are not completely understood. C/EBP-homologous protein (CHOP), a transcription factor induced by ER stress, was found among the most up-regulated genes in livers of PiZ mice that express ATZ and in human livers of patients homozygous for the Z allele. Compared with controls, juvenile PiZ/Chop ^-/- mice showed reduced hepatic ATZ and a transcriptional response indicative of decreased ER stress by RNA-Seq analysis. Livers of PiZ/Chop ^-/- mice also showed reduced SERPINA1 mRNA levels. By chromatin immunoprecipitations and luciferase reporter-based transfection assays, CHOP was found to up-regulate SERPINA1 cooperating with c-JUN, which was previously shown to up-regulate SERPINA1, thus aggravating hepatic accumulation of ATZ. Increased CHOP levels were detected in diseased livers of children homozygous for the Z allele. In summary, CHOP and c-JUN up-regulate SERPINA1 transcription and play an important role in hepatic disease by increasing the burden of proteotoxic ATZ, particularly in the pediatric population.

ATF6 aggravates acinar cell apoptosis and injury by regulating p53/AIFM2 transcription in Severe Acute Pancreatitis

Background: There is no curative therapy for severe acute pancreatitis (SAP) due to poor understanding of its molecular mechanisms. Endoplasmic reticulum (ER) stress is involved in SAP and increased expression of ATF6 has been detected in SAP patients. Here, we aimed to investigate the role of ATF6 in a preclinical SAP mouse model and characterize its regulatory mechanism. Methods: Pancreatic tissues of healthy and SAP patients were collected during surgery. Humanized PRSS1 transgenic mice were treated with caerulein to mimic the SAP development, which was crossed to an ATF6 knockout mouse line, and pancreatic tissues from the resulting pups were screened by proteomics. Adenovirus-mediated delivery to the pancreas of SAP mice was used for shRNA-based knockdown or overexpression. The potential functions and mechanisms of ATF6 were clarified by immunofluorescence, immunoelectron microscopy, Western blotting, qRT-PCR, ChIP-qPCR and luciferase reporter assay. Results: Increased expression of ATF6 was associated with elevated apoptosis, ER and mitochondrial disorder in pancreatic tissues from SAP patients and PRSS1 mice. Knockout of ATF6 in SAP mice attenuated acinar injury, apoptosis and ER disorder. AIFM2, known as a p53 target gene, was identified as a downstream regulatory partner of ATF6, whose expression was increased in SAP. Functionally, AIFM2 could reestablish the pathological disorder in SAP tissues in the absence of ATF6. p53 expression was also increased in SAP mice, which was downregulated by ATF6 knockout. p53 knockout significantly suppressed acinar apoptosis and injury in SAP model. Mechanistically, ATF6 promoted AIFM2 transcription by binding to p53 and AIFM2 promoters. Conclusion: These results reveal that ATF6/p53/AIFM2 pathway plays a critical role in acinar apoptosis during SAP progression, highlighting novel therapeutic target molecules for SAP.

Dietary walnut as food factor to rescue from NSAID-induced gastrointestinal mucosal damages

Nuclear factor erythroid-derived 2-like 2 (Nrf-2) is transcription factor implicated in the antioxidant response element-mediated induction of endogenous antioxidant enzyme such as heme oxygenase-1 (HO-1), glutamate-cysteine ligase, and NAD(P)H quinone dehydrogenase 1, among which HO-1 is an enzyme catalyzing the degradation of heme.producing biliverdin, ferrous iron, and carbon monoxide. In the stomach, as much as regulating gastric acid secretions, well-coordinated establishment of defense system stands for maintaining gastric integrity. In previous study, author et al. for the first time discovered HO-1 induction was critical in affording faithful gastric defense against various irritants including Helicobacter pylori infection, stress, alcohol, non-steroidal anti-inflammatory drugs (NSAIDs), aspirin, and toxic bile acids. In this review article, we can add the novel evidence that dietary walnut intake can be reliable way to rescue from NSAIDs-induced gastrointestinal damages via the induction of HO-1 transcribed with Nrf-2 through specific inactivation of Keap-1. From molecular exploration to translational animal model of indomethacin-induced gastrointestinal damages, significant induction of HO-1 contributed to rescuing from damages. In addition to HO-1 induction action relevant to walnut, we added the description the general actions of walnut extracts or dietary intake of walnut regarding cytoprotection and why we have focused on to NSAID damages.

Ultra-structural study of the indomethacin-induced apoptosis and autophagy in rat gastric parietal cells

BACKGROUND AND AIM OF THE WORK

Indomethacin (IND), a non-steroidal anti-inflammatory drug, can induce gastric mucosal ulcerations. To date, the ultra-structural changes in the parietal cells (PCs) of the gastric mucosa following the intake of IND are mostly unknown. We carried out the current investigation to get insights into this issue.

MATERIALS AND METHODS

We established an animal model consisting of 35 adult male Sprague Dawley rats. The animals were divided into three groups, including; control (normal feeding), fasting, and indomethacin-treated groups. After treatment of 18-h fasting rats with IND, they were sacrificed at 3, 6, and 12-h intervals. The morphological features, including the apoptotic, and autophagic changes in the gastric mucosa PCs were examined using transmission electron microscopy.

RESULTS

In normal feeding animals (control group), the gastric PCs were present in various stages of activity. Fasting was associated with the predominance of the inactive parietal cells with features of up-regulated autophagy. In the IND -treated animals (at 3-h interval), PCs showed prominent autophagic changes, and subtle apoptotic cell death. In the IND -treated animals (at 6-12-h interval), PCs showed prominent apoptotic changes, and subtle autophagic features.

CONCLUSIONS

Our study indicates that IND treatment could induce gastropathy through time-dependent alterations in the autophagic and apoptotic machinery of PCs. Further studies are needed to examine the underlying molecular mechanisms.

Neuroprotective Effects of Chrysin on Diclofenac-Induced Apoptosis in SH-SY5Y Cells

Accumulating evidences demonstrated that Reactive Oxygen Species (ROS) may lead to serious damages to numerous cellular biomolecules, consequently resulting in the development of several neurological diseases. Diclofenac (Dic), the most widely preferred non-steroidal anti-inflammatory drug (NSAID) induces apoptosis by an alteration in function of mitochondria and creation of ROS. Chrysin (Chr) is a naturally active component that is found in numerous plants and bee products and retains strong neuroprotective and antioxidant properties. However its effect of Dic induced injury on SH-SY5Y neuron cells have not been investigated to date. The goal of present research was to study the molecular mechanisms of Chr protection from oxidative injury caused by Dic in SH-SY5Y cells. Dic induced significant toxicity on the cells and this effect was reversed by pre-treatment with Chr. Dic triggered a noteworthy increase in the cellular ROS and Lipid peroxidation (LPO) levels and decrease in Total antioxidant status (TAS) level while pre-treatment with Chr reversed these effects. Dic induction increased the Bax, cytochrome c, cas-3, cas-8 and p53 expression at gene transcription level. Elevated levels of these genes considerably decreased by Chr pre-treatment revealing the defensive effects of Chr. The results obviously presented that exposure of SH-SY5Y with Dic resulted in oxidative stress and apoptosis while pre-treatment of neuron cells with Chr protects the cells against apoptosis triggered by Dic induction.

Natural polyphenols prevent indomethacin-induced and diclofenac-induced Caco-2 cell death by reducing endoplasmic reticulum stress regardless of their direct reactive oxygen species scavenging capacity

Objectives

Indomethacin (INDO) and diclofenac (DIC) can induce intestinal cell death through induction of oxidative stress-mediated ER stress and mitochondrial dysfunction. This study investigated the cytoprotective potential of 11 polyphenols, namely caffeic acid (CAF), curcumin (CUR), epigallocatechin gallate (EGCG), gallic acid (GAL), hypophyllanthin (HYPO), naringenin (NAR), phyllanthin (PHY), piperine (PIP), quercetin (QUE), rutin (RUT) and silymarin (SLY) against these two NSAIDs in Caco-2 cells.

Methods

Reactive oxygen species (ROS) production was determined with fluorescence spectroscopy using specific probes (DHE, DCFH-DA, HPF). Cell viability and mitochondrial function were assessed by MTT and TMRE assays. The mRNA levels of Bax, Bcl-2 and CHOP proteins were determined by quantitative real-time polymerase chain reaction technique.

Key findings

All test polyphenols reduced NSAIDs-mediated ROS production. Only EGCG, QUE and RUT protected INDO-/DIC-induced cell death. These three polyphenols suppressed Bax/Bcl-2 mRNA ratio, CHOP up-regulation and MMP disruption in NSAIDs-treated cells. CAF and NAR prevented cytotoxicity from INDO, but not DIC. The cytoprotective effect of NAR, but not CAF, involved alteration of Bax/Bcl-2 mRNA ratio or MMP disruption, but not CHOP transcription.

Conclusion

The cytoprotective activity of polyphenols against NSAIDs-induced toxicity stemmed from either suppression of CHOP-related ER and mitochondria stresses or other CHOP-independent pathways, but not from the intrinsic ROS scavenging capacity.

Epoxy Fatty Acids Are Promising Targets for Treatment of Pain, Cardiovascular Disease and Other Indications Characterized by Mitochondrial Dysfunction, Endoplasmic Stress and Inflammation

Bioactive lipid mediators resulting from the metabolism of polyunsaturated fatty acids (PUFA) are controlled by many pathways that regulate the levels of these mediators and maintain homeostasis to prevent disease. PUFA metabolism is driven primarily through three pathways. Two pathways, the cyclooxygenase (COX) and lipoxygenase (LO) enzymatic pathways, form metabolites that are mostly inflammatory, while the third route of metabolism results from the oxidation by the cytochrome P450 enzymes to form hydroxylated PUFA and epoxide metabolites. These epoxygenated fatty acids (EpFA) demonstrate largely anti-inflammatory and beneficial properties, in contrast to the other metabolites formed from the degradation of PUFA. Dysregulation of these systems often leads to chronic disease. Pharmaceutical targets of disease focus on preventing the formation of inflammatory metabolites from the COX and LO pathways, while maintaining the EpFA and increasing their concentration in the body is seen as beneficial to treating and preventing disease. The soluble epoxide hydrolase (sEH) is the major route of metabolism of EpFA. Inhibiting its activity increases concentrations of beneficial EpFA, and often disease states correlate to mutations in the sEH enzyme that increase its activity and decrease the concentrations of EpFA in the body. Recent approaches to increasing EpFA include synthetic mimics that replicate biological activity of EpFA while preventing their metabolism, while other approaches focus on developing small molecule inhibitors to the sEH. Increasing EpFA concentrations in the body has demonstrated multiple beneficial effects in treating many diseases, including inflammatory and painful conditions, cardiovascular disease, neurological and disease of the central nervous system. Demonstration of efficacy in so many disease states can be explained by the fundamental mechanism that EpFA have of maintaining healthy microvasculature and preventing mitochondrial and endoplasmic reticulum stress. While there are no FDA approved methods that target the sEH or other enzymes responsible for metabolizing EpFA, current clinical efforts to test for efficacy by increasing EpFA that include inhibiting the sEH or administration of EpFA mimics that block metabolism are in progress.

Regulation of interferon signaling in response to gut microbes by autophagy

The cellular degradative pathway of autophagy prevents unrestrained inflammatory signaling by removing intracellular microbes, damaged organelles, and other factors that trigger immune reactions. Consistent with this function, a common variant of the autophagy gene ATG16L1 is associated with susceptibility to inflammatory bowel disease (IBD), a disorder characterized by a chronic immune reaction directed against the gut microbiota. We recently contributed to our understanding of the link between autophagy and inflammatory signaling in the intestine by demonstrating that autophagy proteins including ATG16L1 are necessary in the epithelium to prevent a spontaneous type I interferon response to the gut microbiota. Enhanced innate immunity that occurs upon autophagy inhibition is protective in mouse models of infection by an enteric bacterial pathogen and acute epithelial injury. Although avoiding excess immune reactions towards the microbiota is necessary to prevent IBD, these observations indicate that autophagy hampers productive immunity at the intestinal epithelial barrier in certain contexts. Here, we discuss how this counterintuitive consequence of autophagy inhibition can be reconciled with the established beneficial role of the pathway.

Targeting MAPKs, NF-κB, and PI3K/AKT pathways by methyl palmitate ameliorates ethanol-induced gastric mucosal injury in rats

Excessive drinking of alcohol has been frequently associated with gastric injury; however, its underlying molecular mechanisms have been inadequately investigated. Methyl palmitate (MP) has demonstrated marked hepato-, cardio- and pulmonary protective features; however, its effects on ethanol-induced gastric injury have not been studied. The aim of the present study was to evaluate the potential gastroprotective activity of MP against ethanol-evoked gastric mucosal damage in rats and associated molecular mechanisms, for example, mitogen-activated protein kinases (MAPKs), nuclear factor κB (NF-κB), and phosphoinositide 3 kinase/protein kinase B (PI3K/AKT) pathways. The rat stomachs were examined in terms of the inflammatory, oxidative, and apoptotic perturbations. Current data demonstrated that pretreatment with MP attenuated the gross gastric damage, scores of ulcer index, area of mucosal lesions and histopathology outcomes; actions which were similar to the reference antiulcer omeprazole. MP inhibited NF-κB expression, its nuclear translocation, and the expression of its downstream signals, for example, tumor necrosis factor-α and myeloperoxidase besides restoration of interleukin-10 levels. Western blot analysis revealed that MP counteracted the disruption of MAPKs signaling via lowering p-c-Jun N-terminal kinase 1/2 (p-JNK1/2) expression and restoring the phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2) levels without affecting p-p38MAPK levels. Additionally, MP improved the antioxidant milieu via diminishing lipid peroxides and enhancing glutathione, glutathione peroxidase, total antioxidant capacity and mucosal nitric oxide. In the context of apoptosis, MP inhibited the cleavage of caspase-3 and poly(ADP-ribose)polymerase (PARP) and Bax protein expression with upregulating B cell lymphoma-2 expression (Bcl-2), thus, promoting gastric cellular survival. This was confirmed by MP activation of the PI3K/AKT pathway manifested by enhanced expression of PI3K p110α and p-AKT. Together, the present findings report the gastroprotective actions of MP mediated via its anti-inflammatory, antioxidant, and antiapoptotic actions. The underlying molecular mechanisms involve, at least partly, the modulation of MAPKs, NF-κB and PI3K/AKT transduction.

Transcriptomic profiling of Hydra magnipapillata after exposure to naproxen

The extensive use in humans and animals of nonsteroidal anti-inflammatory drugs (NSAIDs) increases their possible impact on aquatic organisms. In the present study, we investigated acute toxicity, morphological responses, and potential physiological and metabolic impacts of naproxen exposure on Hydra magnipapillata. The median lethal concentrations (LC₅₀) of naproxen in H. magnipapillata were 51.999 mg/L, 44.935 mg/L, and 42.500 mg/L after exposure for 24, 48, and 72 h, respectively. Morphological observation of the exposed Hydra showed that 40 mg/L naproxen stimulated the contraction of body column and tentacles after 24 h. A KEGG pathway analysis of the genes differentially expressed in the Hydra after exposure to naproxen for 6, 24, or 48 h demonstrated various cellular and metabolic effects, including protein processing in the endoplasmic reticulum, Wnt signaling, and tryptophan metabolism. These results suggest that exposure to naproxen affects the genetic material, inflammatory processes, and metabolic processes of aquatic organisms.

Anti-inflammatory effect and potential mechanism of betulinic acid on λ-carrageenan-induced paw edema in mice

λ-Carrageenan (Carr), a seaweed polysaccharide, is used as a proinflammatory agent in research. Betulinic acid (BA), a naturally occurring pentacyclic triterpenoid, exerts immunomodulatory, antioxidant, anti-inflammatory, antitumor, anti-malarial and anti-HIV effects. The aim of this study was to investigate whether BA exerts anti-inflammatory effect against Carr-induced paw edema in mice, and how BA could mediate the expression of inflammation-associated MAPK-COX-2-PGE₂ signal pathway. BA pretreatment significantly reduced the inflammatory response to Carr-induced paw edema, especially at 4 h after injection. BA reduced the serum levels of pro-inflammatory cytokines, such as IL-1α, IL-1β, IL-5, IL-6, GM-CSF, KC, MCP-1 and PGE₂ in Carr-treated mice, and increased those of anti-inflammatory cytokines, such as IL-12. It also increased SOD, CAT and GSH-Px activities, and GSH content, and reduced MDA content in the liver of Carr-treated mice. Besides, BA reduced neutrophil infiltration in the basal and subcutaneous layers of the paw of Carr-treated mice, decreased the expression of COX-2 protein, and reduced the phosphorylation of JNK, p38 and ERK1/2. These results indicated that the protective effect of BA on Carr-induced paw edema might be due to its alleviation of inflammatory response and inhibition of oxidative stress, possibly by inhibiting MAPK-COX-2-PGE₂ signaling pathway activation.