Ophiopogonin D maintains Ca2+ homeostasis in rat cardiomyocytes in vitro by upregulating CYP2J3/EETs and suppressing ER stress

Ophiopogonin D Alleviates Sepsis-Induced Acute Lung Injury Through Improving Microvascular Endothelial Barrier Dysfunction via Inhibition of HIF-1α-VEGF Pathway

Pulmonary endothelial barrier dysfunction is a hallmark of sepsis-induced acute lung injury (ALI). Ophiopogonin D (OP-D), isolated from the roots of Ophiopogon japonicus, is involved in regulating inflammation, apoptosis and intestinal permeability. However, the role of OP-D in ALI has not been reported and the related mechanisms remain unclear. In this study, cecal ligation and puncture (CLP) was used to establish a septic ALI model in mice. We found that OP-D effectively alleviated lung pathological damage. Moreover, OP-D decreased pulmonary microvascular permeability, restrained the inflammatory response and apoptosis in murine lung tissues and LPS-exposed PMVECs. Specifically, OP-D exerted the beneficial effects via mediating the inactivation of HIF-1α-VEGF pathway, which was partly abrogated by the overexpression of HIF-1α. Collectively, our findings showed that OP-D protected against sepsis-induced ALI through improving pulmonary microvascular endothelial barrier dysfunction via suppressing HIF-1α-VEGF pathway.

Impact of Oxidative Stress and Neuroinflammation on Sarco/Endoplasmic Reticulum Ca2+-ATPase 2b Downregulation and Endoplasmic Reticulum Stress in Temporal Lobe Epilepsy

Epilepsy is one of the most common neurological disorders. Calcium dysregulation and neuroinflammation are essential and common mechanisms in epileptogenesis. Sarco/endoplasmic reticulum (ER) Ca2+-ATPase 2b (SERCA2b), a crucial calcium regulatory pump, plays pathological roles in various calcium dysregulation-related diseases. However, the link between SERCA2b and neuroinflammation in epilepsy remains undetermined. This study aimed to establish the relationship between SERCA2b, oxidative stress, and neuroinflammation in epilepsy to elucidate the underlying molecular mechanism in epileptogenesis. Neuroinflammation and oxidative stress were induced in N2a cells using lipopolysaccharide (LPS) and hydrogen peroxide (H2O2). However, experimental temporal lobe epilepsy (TLE) was induced in mice using pilocarpine. Further, effects of oxidative stress and neuroinflammation on SERCA2b and ER stress markers were assessed at protein and mRNA levels. Calcium imaging was employed to determine intracellular calcium levels. SERCA2b expression significantly decreased after LPS, H2O2, and pilocarpine exposure at both mRNA and protein levels, mediated by upregulating neuroinflammation. This downregulation of SERCA2b was associated with increased production of reactive oxygen species and elevated intracellular calcium levels, leading to elevated ER stress markers. Our findings highlight a link between oxidative stress, neuroinflammation and SERCA2b in TLE. The results suggest that targeting SERCA2b could restore calcium homeostasis and ER stress processes, potentially providing a therapeutic option for TLE. This study underscores the importance of SERCA2b in the pathophysiology of epilepsy and its potential as a therapeutic target.

Differential lipid signaling from CD4+ and CD8+ T cells contributes to type 1 diabetes development

Introduction

We reported that Ca2+-independent phospholipase A2β (iPLA2β)-derived lipids (iDLs) contribute to type 1 diabetes (T1D) onset. As CD4+ and CD8+ T cells are critical in promoting β-cell death, we tested the hypothesis that iDL signaling from these cells participates in T1D development.

Methods

CD4+ and CD8+ T cells from wild-type non-obese diabetic (NOD) and NOD.iPLA2β+/- (NOD.HET) mice were administered in different combinations to immunodeficient NOD.scid.

Results

In mice receiving only NOD T cells, T1D onset was rapid (5 weeks), incidence 100% by 20 weeks, and islets absent. In contrast, onset was delayed 1 week and incidence reduced 40%-50% in mice receiving combinations that included NOD.HET T cells. Consistently, islets from these non-diabetic mice were devoid of infiltrate and contained insulin-positive β-cells. Reduced iPLA2β led to decreased production of proinflammatory lipids from CD4+ T cells including prostaglandins and dihydroxyeicosatrienoic acids (DHETs), products of soluble epoxide hydrolase (sEH), and inhibition of their signaling decreased (by 82%) IFNγ+CD4+ cells abundance. However, only DHETs production was reduced from CD8+ T cells and was accompanied by decreases in sEH and granzyme B.

Discussion

These findings suggest that differential select iDL signaling in CD4+ and CD8+ T cells contributes to T1D development, and that therapeutics targeting such signaling might be considered to counter T1D.

Ophiopogonin D: review of pharmacological activity

Background

Ophiopogon D is an important natural organic compound in Ophiopogon japonicus, which often has significant biological activity.

Purpose

The purpose of this review is to systemically summarize and discuss the pharmacological activity and underlying mechanisms of OP-D in recent years.

Method

PubMed and Web of Science were searched with the keywords:"Ophiopogon japonicus", "Ophiopogon D" "pharmacology", and "pharmacokinetics". There was no restriction on the publication year, and the last search was conducted on 1 Jan 2024.

Results

Emerging evidence suggests that OP-D possess numerous pharmacological activities, including bone protection, cardiovascular protection, immune regulation, anti-cancer, anti-atherosclerosis, anti-inflammatory and anti-NAFLD.

Conclusion

OP-D has a potential value in the prevention and treatment of many diseases. We hope that this review will contribute to therapeutic development and future studies of OP-D.

The involvement of soluble epoxide hydrolase in the development of cardiovascular diseases through epoxyeicosatrienoic acids

Arachidonic acid (AA) has three main metabolic pathways: the cycloxygenases (COXs) pathway, the lipoxygenases (LOXs) pathway, and the cytochrome P450s (CYPs) pathway. AA produces epoxyeicosatrienoic acids (EETs) through the CYPs pathway. EETs are very unstable in vivo and can be degraded in seconds to minutes. EETs have multiple degradation pathways, but are mainly degraded in the presence of soluble epoxide hydrolase (sEH). sEH is an enzyme of bifunctional nature, and current research focuses on the activity of its C-terminal epoxide hydrolase (sEH-H), which hydrolyzes the EETs to the corresponding inactive or low activity diol. Previous studies have reported that EETs have cardiovascular protective effects, and the activity of sEH-H plays a role by degrading EETs and inhibiting their protective effects. The activity of sEH-H plays a different role in different cells, such as inhibiting endothelial cell proliferation and migration, but promoting vascular smooth muscle cell proliferation and migration. Therefore, it is of interest whether the activity of sEH-H is involved in the initiation and progression of cardiovascular diseases by affecting the function of different cells through EETs.

The recent advance and prospect of natural source compounds for the treatment of heart failure

Heart failure is a continuously developing syndrome of cardiac insufficiency caused by diseases, which becomes a major disease endangering human health as well as one of the main causes of death in patients with cardiovascular diseases. The occurrence of heart failure is related to hemodynamic abnormalities, neuroendocrine hormones, myocardial damage, myocardial remodeling etc, lead to the clinical manifestations including dyspnea, fatigue and fluid retention with complex pathophysiological mechanisms. Currently available drugs such as cardiac glycoside, diuretic, angiotensin-converting enzyme inhibitor, vasodilator and β receptor blocker etc are widely used for the treatment of heart failure. In particular, natural products and related active ingredients have the characteristics of mild efficacy, low toxicity, multi-target comprehensive efficacy, and have obvious advantages in restoring cardiac function, reducing energy disorder and improving quality of life. In this review, we mainly focus on the recent advance including mechanisms and active ingredients of natural products for the treatment of heart failure, which will provide the inspiration for the development of more potent clinical drugs against heart failure.

TPPU inhibits inflammation-induced excessive autophagy to restore the osteogenic differentiation potential of stem cells and improves alveolar ridge preservation

Inflammation-induced autophagy is a double-edged sword. Dysfunction of autophagy impairs the differentiation capacity of mesenchymal stem cells and enhances inflammation-induced bone loss. Tooth extraction with periodontal and/or endodontic lesions exacerbates horizontal and vertical resorption of alveolar bone during the healing period. Alveolar socket preservation (ASP) procedure following tooth extraction has important clinical implications for future prosthodontic treatments. Studies have shown that epoxyeicosatrienoic acids (EETs) have significant anti-inflammatory effects and participate in autophagy. However, whether EETs can minimize alveolar bone resorption and contribute to ASP by regulating autophagy levels under inflammatory conditions remain elusive. Here, we figured out that LPS-induced inflammatory conditions increased the inflammatory cytokine and inhibited osteogenic differentiation of human dental pulp stem cells (hDPSCs), and led to excessive autophagy of hDPSCs. Moreover, we identified that increased EETs levels using TPPU, a soluble epoxide hydrolase inhibitor, reversed these negative outcomes. We further demonstrated the potential of TPPU to promote early healing of extraction sockets and ASP, and speculated that it was related to autophagy. Taken together, these results suggest that targeting inhibition of soluble epoxide hydrolase using TPPU plays a protective role in the differentiation and autophagy of mesenchymal stem cells and provides potential feasibility for applying TPPU for ASP, especially under inflammatory conditions.

Effect of Traditional Chinese Medicine on the Cardiovascular Diseases

Background: Traditional Chinese medicine (TCM) is the health care system developed with the help of clinical trials that are based ideally on the scientific model of regulation. Objective: This systematic health care system relies on some specific unique theories and practical experiences to treat and cure diseases, thus enhancing the public's health. Review Methodology: The current review covers the available literature from 2000 to 2021. The data was collected from journals research articles, published books, thesis, and electronic databases, search engines such as Google Scholar, Elsevier, EBSCO, PMC, PubMed, ScienceDirect, Willey Online Library, Springer Link, and CNKI) searching key terms, cardiovascular disease, traditional Chinese medicines, natural products, and bioactive compounds. Full-length articles and abstracts were screened for the collection of information included in the paper. Results: Clinical trials on the TCM and basic research carried out on its mechanism and nature have led to the application and development of the perfect design of the research techniques, for example, twofold striking in acupuncture that aid in overcoming the limitations and resistances in integrating and applicability of these experiences and trials into the pre-existing biomedical models. Furthermore, TCM has also been utilized from ancient times to treat heart diseases in Asia, particularly in China, and is now used by people in many other areas. Cardiovascular disease (CVD) is mainly developed by oxidative stress. Hence antioxidants can be beneficial in treating this particular disease. TCM has a wide variety of antioxidant components. Conclusion: The current review article summarizes the underlying therapeutic property of TCM and its mechanism. It also overviews the evidence of the mechanism of TCM action in CVD prevention by controlling oxidative stress and its signaling pathway.

Liriopogons (Genera Ophiopogon and Liriope, Asparagaceae): A Critical Review of the Phytochemical and Pharmacological Research

The closely related genera Liriope and Ophiopogon (Asparagaceae), collectively known in English as liriopogons, have similar therapeutic uses in treating cough, rheumatoid arthritis, and cleaning heat. The main aim of this review is to understand the current phytochemical and pharmacological knowledge including an assessment of the quality of the scientific evidence. A literature search was conducted in line with PRISMA guidelines, by retrieving available information up to 2020 from five online resources. The bioactive metabolites of liriopogons include steroidal saponins, flavonoids, polysaccharides, organic acids, phenols. Cardiovascular protective, anti-inflammatory, anti-diabetic, anti-oxidant, anti-cancer, neuroprotective, anti-viral, anti-acute myeloid leukemia and hepatoprotective effects have been at the center of attention. From a toxicological perspective Ophiopogon japonicus seems to be safe. Some problems with the quality of the pharmacological evidence stand out including the application of excessive dose level and methodological problems in the design. Additionally, a reasonable link between local/traditional uses and pharmacological assessment is often vague or not reflected in the text. Future researches on liriopogons are required to use rigorous scientific approaches in research on evidence-based natural products for the future benefits of patients.

Crosstalk between the renin-angiotensin system and the endoplasmic reticulum stress in the cardiovascular system: Lessons learned so far

The renin-angiotensin (Ang) system (RAS) is a complex hormonal system present locally in several tissues such as cardiovascular organs. RAS deregulation through overactivation of the classical arm [Ang-converting enzyme (ACE)/Ang-II/Ang type 1 receptor (AT1R)] has been linked to the development of cardiovascular diseases and activation of endoplasmic reticulum (ER) stress pathways. The ER stress is a condition that, if unresolved, might lead to heart failure, atherosclerosis, hypertension, and endothelial dysfunction. Accumulated evidence has shown that the RAS modulates the UPR activation. Several studies reported increased ER stress markers in response to Ang-II treatment, in both in vivo and in vitro models. Evidence has also pointed that targeting the RAS classical arm through RAS blockers, gene silencing or genetic models leads to lower levels of ER stress markers. Few studies demonstrated protective effects of the counter-regulatory arm (ACE-2/Ang-(1-7)/Mas receptor) over ER stress. However, the crosstalk mechanisms between the arms of the RAS and ER stress remain unclear. In this review, we sought to explore the classical arm of the RAS as a key mechanism in UPR activation and to suggest a possible protective role of the counter-regulatory arm in mitigating ER stress.

Potential therapeutic compounds from traditional Chinese medicine targeting endoplasmic reticulum stress to alleviate rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease which affects about 0.5-1% of people with symptoms that significantly impact a sufferer's lifestyle. The cells involved in propagating RA tend to display pro-inflammatory and cancer-like characteristics. Medical drug treatment is currently the main avenue of RA therapy. However, drug options are limited due to severe side effects, high costs, insufficient disease retardation in a majority of patients, and therapeutic effects possibly subsiding over time. Thus there is a need for new drug therapies. Endoplasmic reticulum (ER) stress, a condition due to accumulation of misfolded proteins in the ER, and subsequent cellular responses have been found to be involved in cancer and inflammatory pathologies, including RA. ER stress protein markers and their modulation have therefore been suggested as therapeutic targets, such as GRP78 and CHOP, among others. Some current RA therapeutic drugs have been found to have ER stress-modulating properties. Traditional Chinese Medicines (TCMs) frequently use natural products that affect multiple body and cellular targets, and several medicines and/or their isolated compounds have been found to also have ER stress-modulating capabilities, including TCMs used in RA treatment by Chinese Medicine practitioners. This review encourages, in light of the available information, the study of these RA-treating, ER stress-modulating TCMs as potential new pharmaceutical drugs for use in clinical RA therapy, along with providing a list of other ER stress-modulating TCMs utilized in treatment of cancers, inflammatory diseases and other diseases, that have potential use in RA treatment given similar ER stress-modulating capacity.

Ophiopogonin D alleviates diabetic myocardial injuries by regulating mitochondrial dynamics

ETHNOPHARMACOLOGICAL RELEVANCE

Ophiopogonin D (OP-D) is a steroidal saponin extracted from Ophiopogon japonicus (Thunb.) Ker Gawl. (Liliaceae), that has been traditionally used to treat cough, sputum, and thirst in some Asian countries. Recently, various pharmacological roles of OP-D have been identified, including anti-inflammatory, cardioprotective, and anti-cancer effects. However, whether OP-D can prevent diabetic myocardial injury remains unknown.

AIM OF THE STUDY

In this study, we aimed to observe the effects of OP-D on the diabetic myocardium.

MATERIALS AND METHODS

Leptin receptor-deficient db/db mice were used as an animal model for type 2 diabetes. The effects of OP-D on blood glucose, blood lipids, myocardial ultrastructure, and mitochondrial function in mice were observed after four weeks of intragastric administration. Palmitic acid was used to stimulate cardiomyocytes to establish a myocardial lipotoxicity model. Cell apoptosis, mitochondrial morphology, and function were observed.

RESULTS

Blood glucose and blood lipid levels were significantly increased in db/db mice, accompanied by myocardial mitochondrial injury and dysfunction. OP-D treatment reduced blood lipid levels in db/db mice and relieved mitochondrial injury and dysfunction. OP-D inhibited palmitic acid induced-mitochondrial fission and dysfunction, reduced endogenous apoptosis, and improved cell survival rate in H9C2 cardiomyocytes. Both in vivo and in vitro models showed increased phosphorylation of DRP1 at Ser-616, reduced phosphorylation of DRP1 at Ser-637, and reduced expression of fusion proteins MFN1/2 and OPA1. Meanwhile, immunofluorescence co-localization analysis revealed that palmitic acid stimulated the translocation of DRP1 protein from the cytoplasm to the mitochondria in H9C2 cardiomyocytes. The imbalance of mitochondrial dynamics, protein expression, and translocation of DRP1 were effectively reversed by OP-D treatment. In isolated mice ventricular myocytes, palmitic acid enhanced cytoplasmic Ca²⁺ levels and suppressed contractility in ventricular myocytes, accompanied by activation of calcineurin, a key regulator of DRP1 dephosphorylation at Ser-637. OP-D reversed the changes caused by palmitic acid.

CONCLUSIONS

Our findings indicate that OP-D intervention could alleviate lipid accumulation and mitochondrial injury in diabetic mouse hearts and palmitic acid-stimulated cardiomyocytes. The cardioprotective effect of OP-D may be mediated by the regulation of mitochondrial dynamics.

A high-throughput cell-based gaussia luciferase reporter assay for measurement of CYP1A1, CYP2B6, and CYP3A4 induction

The induction of cytochrome P450s can result in reduced drug efficacy and lead to potential drug-drug interactions. The xenoreceptors-aryl hydrocarbon receptor (AhR), constitutive androstane receptor (CAR), and pregnane X receptor (PXR)-play key roles in CYP induction by xenobiotics. In order to be able to rapidly screen for the induction of three enzymes (CYP1A1, CYP2B6, and CYP3A4), we generated a stable AhR-responsive HepG2 cell line, a stable CAR-responsive HepG2 cell line, and a stable PXR-responsive HepG2 cell line.To validate these stable xenoreceptor-responsive HepG2 cell lines, we evaluated the induction of the different Gaussia reporter activities, as well as the mRNA and protein expression levels of endogenous CYPs in response to different inducers.The induction of luciferase activity in the stable xenoreceptor-responsive HepG2 cell lines by specific inducers occurred in a concentration dependent manner. There was a positive correlation between the induction of luciferase activities and the induction endogenous CYP mRNA expression levels. These xenoreceptor-responsive HepG2 cell lines were further validated with known CYP1A1, CYP2B6, and CYP3A4 inducers.These stable xenoreceptor-responsive HepG2 cell lines may be used in preclinical research for the rapid and sensitive detection of AhR, CAR, and PXR ligands that induce CYP450 isoforms.

Cardiomyocyte protective effects of thyroid hormone during hypoxia/reoxygenation injury through activating of IGF-1-mediated PI3K/Akt signalling

Ischaemia/reperfusion (I/R) injury is a common clinical condition that results in apoptosis and oxidative stress injury. Thyroid hormone was previously reported to elicit cardiac myocyte hypertrophy and promote cardiac function after cardiac injury. We used an in vivo mouse model of I/R injury and in vitro primary cardiomyocyte culture assays to investigate the effects of thyroid hormone on cardiomyocytes during hypoxia/reoxygenation (H/R) injury. The results showed that T3 pretreatment in vivo significantly improved left ventricular function after I/R injury. In vitro, T3 pretreatment decreased cell apoptosis rate, inhibited caspase‐3 activity and decreased the Bax/Bcl‐2 ration induced by H/R injury. T3 pretreatment significantly attenuated the loss of mitochondrial membrane potential. Furthermore, it was observed that T3 diminished the expression of NCX1 protein and decreased SERCA2a protein expression in H/R‐induced cardiomyocytes, and T3 prevented intracellular Ca²⁺ increase during H/R injury. Also, T3 increased the expression of IGF‐1, and PI3K/Akt signalling in cardiomyocytes under H/R‐induced injury, and that the protective effect of T3 against H/R‐induced injury was blocked by the PI3K inhibitor LY294002. IGF‐1 receptor (IGF‐1R) inhibitor GSK1904529A significantly inhibited the expression of IGF‐1R and PI3K/Akt signalling. In summary, T3 pretreatment protects cardiomyocytes against H/R‐induced injury by activating the IGF‐1‐mediated PI3K/Akt signalling pathway.

Global metabolomic and lipidomic analysis reveals the potential mechanisms of hemolysis effect of Ophiopogonin D and Ophiopogonin D' in vivo

BACKGROUND

OPD and OPD' are the two main active components of Ophiopogon japonicas in Shenmai injection (SMI). Being isomers of each other, they are supposed to have similar pharmacological activities, but the actual situation is complicated. The difference of hemolytic behavior between OPD and OPD' in vivo and in vitro was discovered and reported by our group for the first time. In vitro, only OPD' showed hemolysis reaction, while in vivo, both OPD and OPD' caused hemolysis. In vitro, the primary cause of hemolysis has been confirmed to be related to the difference between physical and chemical properties of OPD and OPD'. In vivo, although there is a possible explanation for this phenomenon, the one is that OPD is bio-transformed into OPD' or its analogues in vivo, the other one is that both OPD and OPD' were metabolized into more activated forms for hemolysis. However, the mechanism of hemolysis in vivo is still unclear, especially the existing literature are still difficult to explain why OPD shows the inconsistent hemolysis behavior in vivo and in vitro. Therefore, the study of hemolysis of OPD and OPD' in vivo is of great practical significance in response to the increase of adverse events of SMI.

METHODS

Aiming at the hemolysis in vivo, this manuscript adopted untargeted metabolomics and lipidomics technology to preliminarily explore the changes of plasma metabolites and lipids of OPD- and OPD'-treated rats. Metabolomics and lipidomics analyses were performed on ultra-high performance liquid chromatography (UPLC) system tandem with different mass spectrometers (MS) and different columns respectively. Multivariate statistical approaches such as principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA) were applied to screen the differential metabolites and lipids.

RESULTS

Both OPD and OPD' groups experienced hemolysis, Changes in endogenous differential metabolites and differential lipids, enrichment of differential metabolic pathways, and correlation analysis of differential metabolites and lipids all indicated that the causes of hemolysis by OPD and OPD' were closely related to the interference of phospholipid metabolism.

CONCLUSIONS

This study provided a comprehensive description of metabolomics and lipidomics changes between OPD- and OPD'-treated rats, it would add to the knowledge base of the field, which also provided scientific guidance for the subsequent mechanism research. However, the underlying mechanism require further research.

Ophiopogonin D Increases SERCA2a Interaction with Phospholamban by Promoting CYP2J3 Upregulation

Ophiopogonin D (OPD), a compound from the Chinese herb Radix Ophiopogonis, reportedly induces increased levels of cytochrome P450 2J3 (CYP2J3)/epoxyeicosatrienoic acids (EETs) and Ca²⁺ in rat cardiomyocytes. Little is known regarding the specific mechanism between CYP2J3 and Ca²⁺ homeostasis. Here, we investigated whether CYP2J3 is involved in the protective action of OPD on the myocardium by activating the Ca²⁺ homeostasis-related protein complex (SERCA2a and PLB) in H9c2 rat cardiomyoblast cells. The interaction between SERCA2a and PLB was measured using fluorescence resonance energy transfer. OPD attenuated heart failure and catalyzed the active transport of Ca²⁺ into the sarcoplasmic reticulum by inducing the phosphorylation of PLB and promoting the SERCA2a activity. These beneficial effects of OPD on heart failure were abolished after knockdown of CYP2J3 in a model of heart failure. Together, our results identify CYP2J3 as a critical intracellular target for OPD and unravel a mechanism of CYP2J3-dependent regulation of intracellular Ca²⁺.

FAM134B Attenuates Seizure-Induced Apoptosis and Endoplasmic Reticulum Stress in Hippocampal Neurons by Promoting Autophagy

Autophagy plays a critical role in epileptic neuronal injury, and recent studies have demonstrated that FAM134B plays an important role in regulating autophagy. However, the effect of FAM134B on epileptic neuronal injury remains unclear. In this study, we investigated the role of FAM134B in neuronal apoptosis and endoplasmic reticulum (ER) stress using the hippocampal neuronal culture model of acquired epilepsy (AE) in vitro. We found that in this model, the level of autophagy significantly increased, indicated by an elevated LC3-II/LC3-I ratio. FAM134B overexpression using lentiviral vectors enhanced autophagy, whereas FAM134B downregulation using lentiviral vectors impaired this process. In addition, the ER Ca2+ concentration was decreased and the intracellular level of reactive oxygen species was increased in this model. FAM134B overexpression was sufficient to reverse these changes. Moreover, FAM134B overexpression attenuated ER stress as shown by a decrease in the expression of C/-EBP homologous protein and glucose-regulated protein 78, and neuronal apoptosis induced by seizure, while FAM134B downregulation caused the opposite effects. Further, pre-treatment with the selective autophagy inhibitor 3-methyladenine abolished the effects of FAM134B on ER stress and neuronal apoptosis. Altogether, we demonstrate that FAM134B is an important regulator of AE-induced ER stress and neuronal apoptosis by controlling autophagy function.

Soluble Epoxide Hydrolase Regulation of Lipid Mediators Limits Pain

The role of lipids in pain signaling is well established and built on decades of knowledge about the pain and inflammation produced by prostaglandin and leukotriene metabolites of cyclooxygenase and lipoxygenase metabolism, respectively. The analgesic properties of other lipid metabolites are more recently coming to light. Lipid metabolites have been observed to act directly at ion channels and G protein-coupled receptors on nociceptive neurons as well as act indirectly at cellular membranes. Cytochrome P450 metabolism of specifically long-chain fatty acids forms epoxide metabolites, the epoxy-fatty acids (EpFA). The biological role of these metabolites has been found to mediate analgesia in several types of pain pathology. EpFA act through a variety of direct and indirect mechanisms to limit pain and inflammation including nuclear receptor agonism, limiting endoplasmic reticulum stress and blocking mitochondrial dysfunction. Small molecule inhibitors of the soluble epoxide hydrolase can stabilize the EpFA in vivo, and this approach has demonstrated relief in preclinical modeled pain pathology. Moreover, the ability to block neuroinflammation extends the potential benefit of targeting soluble epoxide hydrolase to maintain EpFA for neuroprotection in neurodegenerative disease.

Epoxyeicosatrienoic acids inhibit the activation of NLRP3 inflammasome in murine macrophages

Epoxyeicosatrienoic acids (EETs) derived from arachidonic acid exert anti-inflammation effects. We have reported that blocking the degradation of EETs with a soluble epoxide hydrolase (sEH) inhibitor protects mice from lipopolysaccharide (LPS)-induced acute lung injury (ALI). The underlying mechanisms remain essential questions. In this study, we investigated the effects of EETs on the activation of nucleotide-binding domain leucine-rich repeat-containing receptor, pyrin domain-containing-3 (NLRP3) inflammasome in murine macrophages. In an LPS-induced ALI murine model, we found that sEH inhibitor 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl), TPPU, profoundly attenuated the pathological injury and inhibited the activation of the NLRP3 inflammasome, characterized by the reduction of the protein expression of NLRP3, ASC, pro-caspase-1, interleukin precursor (pro-IL-1β), and IL-1β p17 in the lungs of LPS-treated mice. In vitro, primary peritoneal macrophages from C57BL/6 were primed with LPS and activated with exogenous adenosine triphosphate (ATP). TPPU treatment remarkably reduced the expression of NLRP3 inflammasome-related molecules and blocked the activation of NLRP3 inflammasome. Importantly, four EETs (5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET) inhibited the activation of NLRP3 inflammasome induced by LPS + ATP or LPS + nigericin in macrophages in various degree. While the inhibitory effect of 5,6-EET was the weakest. Mechanismly, EETs profoundly decreased the content of reactive oxygen species (ROS) and restored the calcium overload in macrophages receiving LPS + ATP stimulation. In conclusion, this study suggests that EETs inhibit the activation of the NLRP3 inflammasome by suppressing calcium overload and ROS production in macrophages, contributing to the therapeutic potency to ALI.

The Role of Traditional Chinese Medicine in the Regulation of Oxidative Stress in Treating Coronary Heart Disease

Oxidative stress has been closely related with coronary artery disease. In coronary heart disease (CHD), an excess of reactive oxygen species (ROS) production generates endothelial cell and smooth muscle functional disorders, leading to a disequilibrium between the antioxidant capacity and prooxidants. ROS also leads to inflammatory signal activation and mitochondria-mediated apoptosis, which can promote and increase the occurrence and development of CHD. There are several kinds of antioxidative and small molecular systems of antioxidants, such as β-carotene, ascorbic acid, α-tocopherol, and reduced glutathione (GSH). Studies have shown that antioxidant treatment was effective and decreased the risk of CHD, but the effect of the treatment varies greatly. Traditional Chinese medicine (TCM) has been utilized for thousands of years in China and is becoming increasingly popular all over the world, especially for the treatments of cardiovascular diseases. This review will concentrate on the evidence of the action mechanism of TCM in preventing CHD by modulating oxidative stress-related signaling pathways.

Facilitated Ca2+ homeostasis and attenuated myocardial autophagy contribute to alleviation of diabetic cardiomyopathy after bariatric surgery

Bariatric surgery has been reported to relieve diabetic cardiomyopathy (DCM) effectively. However, the mechanisms remain largely unknown. To determine the effects of bariatric surgery on DCM via modulation of myocardial Ca²⁺ homeostasis and autophagy, sleeve gastrectomy (SG), duodenal-jejunal bypass (DJB), and sham surgeries were performed in diabetic rats induced by high-fat diet and a low dose of streptozotocin. Cardiac remodeling was assessed by a series of morphometric and histological analyses. Transthoracic echocardiography and hemodynamic measurements were performed to determine cardiac function. Ca²⁺ homeostasis was evaluated by measuring Ca²⁺ transients with fura-2 AM in isolated ventricular myocytes along with detection of the abundance of Ca²⁺ regulatory proteins in the myocardium. Myocardial autophagic flux was determined by expression of autophagy-related proteins in the absence and presence of chloroquine. Both SG and DJB surgery alleviated DCM morphologically and functionally. Ca²⁺ transients exhibited a significantly higher amplitude and faster decay after SG and DJB, which could be partially explained by increased expression of ryanodine receptor 2, sarco(endo)plasmic reticulum Ca²⁺-2ATPase, 12.6-kDa FK506-binding protein, and hyperphosphorylation of phospholamban. In addition, a lower level of light chain 3B and higher level of p62 were detected after both SG and DJB, which was not reversed by chloroquine treatment and associated with activated mammalian target of rapamycin and attenuated AMP-activated protein kinase signaling pathway. Collectively, these results provided evidence that bariatric surgery could alleviate DCM effectively, which may result, at least in part, from facilitated Ca²⁺ homeostasis and attenuated autophagy, suggesting a potential choice for treatment of DCM when properly implemented. NEW & NOTEWORTHY The present study is the first to investigate the modulation of myocardial Ca²⁺ homeostasis and autophagy after bariatric surgery and to examine its effects on diabetic cardiomyopathy. Bariatric surgery could facilitate myocardial Ca²⁺ homeostasis and attenuate myocardial autophagy, contributing to the alleviation of cardiomyopathy morphologically and functionally in a diabetic rat model.

Ophiopogonin D modulates multiple oncogenic signaling pathways, leading to suppression of proliferation and chemosensitization of human lung cancer cells

BACKGROUND

Ophiopogonin D (OP-D), a steroidal glycoside obtained from the Chinese medicinal plant Ophiopogonin japonicas (the root portion), has been traditionally used to treat fever, inflammation, cough, sputum etc. However, the detailed molecular mechanism(s) underlying its therapeutic actions is still unknown.

HYPOTHESIS

Because nuclear factor-κB (NF-κB), PI3K/AKT, and activator protein-1 (AP-1) signaling cascades have significant functions in cell proliferation, inflammation, and angiogenesis in tumor cells, we hypothesized that OP-D may disrupt these signaling cascades to exert its anticancer effects in human lung-cancer cells.

METHODS

We evaluated the effect of OP-D on multiple signaling cascades and its regulated functional responses in lung cancer cells.

RESULTS

OP-D blocked both basal and cytokine-induced proliferation of human lung-cancer cells and caused down-regulation of the expression of diverse oncogenic gene products through the suppression of NF-κB, PI3K/AKT, and AP-1 pathways; but did not affect JNK, p38 and ERK MAP kinases. Interestingly, OP-D suppressed constitutive NF-κB activation in lung cancer cells via interfering with the IκB kinase activation, which inhibited phosphorylation and caused degradation of IκB-α. OP-D also blocked phosphorylation and the nuclear translocation of p65, thereby suppressing NF-κB reporter activity in lung cancer cells. Besides, OP-D could augment cell death induced by paclitaxel in lung-cancer cells.

CONCLUSION

Overall, the data indicates that OP-D may abrogate diverse signaling cascades linked to tumorigenesis, and can be used in combination with chemotherapeutic agents for cancer therapy.

Tetramethylpyrazine suppresses angiotensin II-induced soluble epoxide hydrolase expression in coronary endothelium via anti-ER stress mechanism

Activation of soluble epoxide hydrolase (sEH) is associated with endothelial dysfunction in hypertension, though the underlying mechanisms are inadequately understood and the role of endoplasmic reticulum (ER) stress is yet to be studied in detail. Tetramethylpyrazine (TMP), a major bioactive ingredient of Chinese herb Chuanxiong, is well-known for its cardiovascular benefits. Nevertheless, whether TMP may protect vascular endothelium from ER stress and whether regulation of sEH is involved remain unknown. This study aimed at investigating the role of ER stress in angiotensin-II (Ang-II)-induced sEH dysregulation and elucidating the significance of ER stress regulation in the vasoprotective effect of TMP. Porcine primary coronary artery endothelial cells (PCECs) were used for western blot, ELISA, and reverse-transcription PCR analysis. Porcine coronary arteries were assessed in a myograph for endothelial dilator function. Ang-II induced expression of ER stress molecules in PCECs meanwhile enhanced sEH expression and decreased 11,12-EET. Exposure of PCECs to the chemical ER stress inducer tunicamycin also increased sEH expression. Inhibition of ER stress suppressed sEH upregulation, resulting in an increase of 11,12-EET. The impairment of endothelium-dependent vasorelaxation induced by Ang-II or tunicamycin was ameliorated by inhibitors of ER stress or sEH. TMP showed comparable inhibitory effect to ER stress inhibitors on the expression of ER stress molecules, the dysregulation of sEH/EET, and the impairment of endothelial dilator function. We demonstrated that ER stress mediates Ang-II-induced sEH upregulation in coronary endothelium. TMP has potent anti-ER stress capacity through which TMP normalizes sEH expression and confers protective effect against Ang-II on endothelial function of coronary arteries.

Extract of Sheng-Mai-San Ameliorates Myocardial Ischemia-Induced Heart Failure by Modulating Ca2+-Calcineurin-Mediated Drp1 Signaling Pathways

Sheng-Mai-San (SMS) is a well-known traditional Chinese medicine (TCM) complex prescription used to treat heart failure (HF) and angina in clinic. However, its potential therapeutic mechanisms remain unclear. The present study evaluated the cardioprotection of extract of SMS (ESMS) on myocardial ischemia (MI)-induced HF, and explored the underlying molecular mechanisms. The results demonstrated that ESMS (728.0 mg/kg) significantly attenuated MI injury-induced HF by improving cardiac function and pathological changes, decreasing lactate dehydrogenase (LDH), creatine kinase (CK) activities, and brain natriuretic peptide (BNP) levels; increasing ATPase activity; and reducing intracellular Ca²⁺ levels in MI-induced HF mice model. It also significantly decreased the apoptotic index. In vitro, ESMS (400 μg/mL) inhibited mitochondrial-dependent myocardial apoptosis by modulating the expression of caspase-3 and the Bcl-2/Bax ratio, and improved mitochondrial function through increasing mitochondrial membrane potential and cellular ATP content. ESMS restored intracellular Ca²⁺ and downregulated the expression of Calcineurin A (CnA), thus inhibiting phosphorylation of dynamin-related protein 1 (Drp1) at Ser616 and increasing phosphorylation of Drp1 at Ser637 to prevent cardiomyocyte mitochondrial fission. Above-mentioned results demonstrated ESMS suppressed mitochondrial-mediated apoptosis in oxygen glucose deprivation (OGD) injured H9c2 cardiomyocytes. These findings suggested that ESMS attenuated MI-induced HF by regulating Ca²⁺ homeostasis and suppressing mitochondrial mediated apoptosis through the modulation of Ca²⁺-calcineurin-mediated Drp1 signaling pathways. Our results provide insight into the mechanism and clinical applications of SMS and suggest a potential therapeutic strategy for HF.

Modulation of mitochondrial dysfunction and endoplasmic reticulum stress are key mechanisms for the wide-ranging actions of epoxy fatty acids and soluble epoxide hydrolase inhibitors

The arachidonic acid cascade is arguably the most widely known biologic regulatory pathway. Decades after the seminal discoveries involving its cyclooxygenase and lipoxygenase branches, studies of this cascade remain an active area of research. The third and less widely known branch, the cytochrome P450 pathway leads to highly active oxygenated lipid mediators, epoxy fatty acids (EpFAs) and hydroxyeicosatetraenoic acids (HETEs), which are of similar potency to prostanoids and leukotrienes. Unlike the COX and LOX branches, no pharmaceuticals currently are marketed targeting the P450 branch. However, data support therapeutic benefits from modulating these regulatory lipid mediators. This is being approached by stabilizing or mimicking the EpFAs or even by altering the diet. These approaches lead to predominantly beneficial effects on a wide range of apparently unrelated states resulting in an enigma of how this small group of natural chemical mediators can have such diverse effects. EpFAs are degraded by soluble epoxide hydrolase (sEH) and stabilized by inhibiting this enzyme. In this review, we focus on interconnected aspects of reported mechanisms of action of EpFAs and inhibitors of soluble epoxide hydrolase (sEHI). The sEHI and EpFAs are commonly reported to maintain homeostasis under pathological conditions while remaining neutral under normal physiological conditions. Here we provide a conceptual framework for the unique and broad range of biological activities ascribed to epoxy fatty acids. We argue that their mechanism of action pivots on their ability to prevent mitochondrial dysfunction, to reduce subsequent ROS formation and to block resulting cellular signaling cascades, primarily the endoplasmic reticulum stress. By stabilizing the mitochondrial - ROS - ER stress axis, the range of activity of EpFAs and sEHI display an overlap with the disease conditions including diabetes, fibrosis, chronic pain, cardiovascular and neurodegenerative diseases, for which the above outlined mechanisms play key roles.