Tanshinone IIA ameliorates experimental diabetic cardiomyopathy by inhibiting endoplasmic reticulum stress in cardiomyocytes via SIRT1

Tanshinone IIA reduces tubulointerstitial fibrosis by suppressing GSDMD-mediated pyroptosis

CONTEXT

Tanshinone IIA (Tan IIA), a bioactive compound derived from the traditional Chinese herb Salvia miltiorrhiza (Family Lamiaceae, Authority Bunge), is well-known for its protective effects in various kidney diseases. However, its role in obstructive nephropathy has not been thoroughly investigated.

OBJECTIVE

This study aimed to explore the protective effects of Tan IIA in a mouse model of unilateral ureteral obstruction (UUO) and to elucidate the cellular and molecular mechanisms underlying these effects.

MATERIALS AND METHODS

Gasdermin D (GSDMD) knockout mice and their wild-type (WT) littermates underwent UUO surgery, with Tan IIA treatment administered 24 h prior. Human proximal tubular cells (HK-2 cells) were treated with TGF-β1 to induce fibrosis (50 ng/mL for 24 h), followed by Tan IIA treatment (5 μM) for an additional 3 h.

RESULTS

Tan IIA significantly reduced the expression of extracellular matrix (ECM) components, including collagen I, α-smooth muscle actin (α-SMA), vimentin and fibronectin, in UUO mice. Tan IIA attenuated GSDMD-mediated pyroptosis. However, in GSDMD knockout mice subjected to UUO, the protective effects of Tan IIA on ECM gene expression and collagen deposition in the tubular interstitium were reduced. In vitro studies showed that Tan IIA reduced GSDMD activation and fibronectin protein expression in HK-2 cells.

DISCUSSION AND CONCLUSIONS

Tan IIA may mitigate GSDMD-mediated pyroptosis in renal tubular epithelial cells (RTECs) and reduce kidney fibrosis, highlighting its potential as a therapeutic strategy to prevent the progression of kidney disease after ureteral obstruction.

Magnesium-assisted hydrogen improves isoproterenol-induced heart failure

Heart failure (HF) is a leading cause of mortality among patients with cardiovascular disease and is often associated with myocardial apoptosis and endoplasmic reticulum stress (ERS). While hydrogen has demonstrated potential in reducing oxidative stress and ERS, recent evidence suggests that magnesium may aid in hydrogen release within the body, further enhancing these protective effects. This study aimed to investigate the cardioprotective effects of magnesium in reducing apoptosis and ERS through hydrogen release in a rat model of isoproterenol (ISO)-induced HF. Magnesium was administered orally to ISO-induced HF rats, which improved cardiac function, reduced myocardial fibrosis and cardiac hypertrophy, and lowered the plasma levels of creatine kinase-MB, cardiac troponin-I, and N-terminal B-type natriuretic peptide precursor in ISO-induced HF rats. It also inhibited cardiomyocyte apoptosis by upregulating B-cell lymphoma-2, downregulating Bcl-2-associated X protein, and suppressing ERS markers (glucose-related protein 78, activating transcription factor 4, and C/EBP-homologous protein). Magnesium also elevated hydrogen levels in blood, plasma, and cardiac tissue, as well as in artificial gastric juice and pure water, where hydrogen release lasted for at least four hours. Additionally, complementary in vitro experiments were conducted using H9C2 cardiomyocyte injury models, with hydrogen-rich culture medium as the intervention. Hydrogen-rich culture medium improved the survival and proliferation of ISO-treated H9C2 cells, reduced the cell surface area, inhibited apoptosis, and downregulated ERS pathway proteins. However, the protective effects of hydrogen were negated by tunicamycin (an inducer of ERS) in H9C2 cells. In conclusion, magnesium exerts significant cardioprotection by mitigating ERS and apoptosis through hydrogen release effects in ISO-induced HF.

Post-translational acylation of proteins in cardiac hypertrophy

Acylations are post-translational modifications in which functional groups are attached to amino acids on proteins. Most acylations (acetylation, butyrylation, crotonylation, lactylation, malonylation, propionylation and succinylation) involve lysine but cysteine (palmitoylation) and glycine (myristoylation) residues can also be altered. Acylations have important roles in physiological and pathophysiological processes, including cardiac hypertrophy and related cardiovascular diseases. These post-translational modifications influence chromatin architecture, transcriptional regulation and metabolic pathways, thereby affecting cardiomyocyte function and pathology. The dynamic interaction between these acylations and their regulatory enzymes, such as histone acetyltransferases, histone deacetylases and sirtuins, underscores the complexity of cellular homeostasis and pathological processes. Emerging evidence highlights the therapeutic potential of targeting acylations to modulate enzyme activity and metabolite levels, offering promising avenues for novel treatments. In this Review, we explore the diverse mechanisms through which acylations contribute to cardiac hypertrophy, highlighting the complexity and potential therapeutic targets in this regulatory network.

Traditional Chinese medicine in the prevention of diabetes mellitus and cardiovascular complications: mechanisms and therapeutic approaches

Diabetes mellitus (DM) is a chronic endocrine and metabolic disorder characterized by persistent hyperglycemia that poses serious threats to human health and quality of life. The morbidity, disability, and mortality rates of cardiovascular complications stemming from chronic hyperglycemia are primary factors affecting the lifespan of patients with diabetes. Currently, there is no cure for DM. Standard biomedical treatments mostly control the symptoms using insulin injections or oral hypoglycemic drugs. Although the effect of standard biomedical therapy is remarkable, its long-term use is prone to toxic side effects. Numerous studies have recently found that Traditional Chinese Medicine (TCM) has strong advantages in the prevention and treatment of DM and cardiovascular complications (DACC). The collection, processing, preparation and clinical use of TCM are guided by the theory of TCM and follow the "holistic concept." Multiple components, pathways, and targets form the basis for the use of TCM in treating multiple parts and organs of the body simultaneously. TCM is mainly derived from natural medicines and their processed products and has fewer side effects. TCM is clinically used as compound prescriptions, botanical drugs, and monomers. TCM, either independently or in combination with standard biomedical treatments, has shown unique therapeutic advantages. This review aimed to explore the recently reported mechanisms of action of TCM in the prevention and treatment of DACC. These findings will aid the optimization of the current therapy or formation of a therapeutic schedule for integrated TCM and standard biomedical treatments.

Oxymatrine alleviates ALD-induced cardiac hypertrophy by regulating autophagy via activation Nrf2/SIRT3 signaling pathway

BACKGROUND

Cardiac hypertrophy is a prevalent early pathological manifestation in various cardiovascular diseases, lacking effective interventions to impede its progression. Although oxymatrine (OMT) has shown potential benefits for cardiac function, its therapeutic efficacy and mechanism in cardiac hypertrophy remain incompletely understood. Notably, mitochondrial damage and dysregulated autophagy are pivotal pathogenic mechanisms in cardiac hypertrophy.

PURPOSE

We investigate the pharmacological characteristics and mechanism of OMT in mitochondrial function and autophagy in cardiac hypertrophy.

STUDY DESIGN AND METHODS

A murine model of cardiac hypertrophy was induced by aldosterone in combination with high-salt drinking water, while primary cardiomyocyte hypertrophy was induced by aldosterone in vitro. Cardiac hypertrophy was assessed using echocardiography and histopathological staining. Autophagosomes and mitochondrial morphology were visualized by transmission electron microscopy. Levels of reactive oxygen species (ROS), malondialdehyde (MDA), and adenosine triphosphate (ATP) were quantified using commercial kits. The binding affinity of OMT with Nrf2 was assessed through molecular docking. Furthermore, adenovirus, agonists, and inhibitors were employed to modulate Nrf2, followed by quantitative real-time polymerase chain reaction (qRT-PCR), immunoblotting, co-immunoprecipitation, chromatin immunoprecipitation, immunohistochemistry, and cellular thermal shift assay.

RESULTS

OMT effectively attenuated aldosterone-induced cardiac hypertrophy both in vivo and in vitro. OMT promoted the activation of Nrf2, leading to elevated SIRT3 expression and enhanced autophagolysosome fusion, thereby modulating mitophagy and improving mitochondrial function. Moreover, the cardioprotective effects of OMT were abolished upon silencing or inhibition of Nrf2. OMT binds to Nrf2, facilitating its dissociation and nuclear translocation.

CONCLUSION

OMT activates Nrf2, consequently enhancing SIRT3 transcription, restoring autophagic flux, and preserving mitochondrial integrity, thereby mitigating aldosterone-induced cardiac hypertrophy. In summary, our study is the first to discover and confirm that OMT can stabilize Nrf2, promoting its activation and subsequently up-regulating SIRT3, which in turn facilitates mitochondrial autophagy. Additionally, PARKIN appears to play a key role in SIRT3-mediated regulation of mitophagy, warranting further investigation.

SIRT1: a potential therapeutic target for coronary heart disease combined with anxiety or depression

Coronary heart disease (CHD) combined with anxiety or depression is increasingly receiving attention in the clinical field of cardiology, and exploring the comorbidity pathological mechanisms of cardiovascular disease combined with psychological disorders is a hot research topic for scholars in this field. Current research suggests that Silent Information Regulatory Factor 1 (SIRT1) may serve as a potential biomarker for the comorbidity mechanism and treatment of CHD with anxiety or depression. SIRT1 is considered a promising therapeutic target for CHD combined with anxiety or depression, with the ability to regulate inflammatory cytokine levels, alleviate oxidative stress damage, activate multiple signalling pathways, reduce platelet hyperresponsiveness, and exert neuroprotective and cardioprotective effects. In this comprehensive review, we deeply studied the structure, function, and mechanism of SIRT1, and discussed its protective effects in the cardiovascular and nervous system. The latest progress in the mechanism of SIRT1's role in CHD combined with anxiety or depression was emphasised, including its specific mechanisms in regulating inflammatory response, alleviating oxidative stress, and mediating various signalling pathways. In addition, this article also summarises the therapeutic potential of SIRT1 as a potential biomarker in patients with CHD combined with anxiety or depression.

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

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

Tanshinone IIA, a component of Salvia miltiorrhiza Bunge, attenuated sepsis-induced liver injury via the SIRT1/Sestrin2/HO-1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

As a traditional Chinese medicine, Salvia miltiorrhiza Bunge has been widely used to treat ischemic and inflammation-related diseases for more than 2000 years. S. miltiorrhiza Bunge has hepatoprotective effects, but the underlying mechanism is not fully understood.

OBJECTIVE

To verify the effect of tanshinone IIA (Tan IIA), the main fat-soluble component of S. miltiorrhiza Bunge, on liver damage induced by sepsis/LPS-induced inflammation and further explore the underlying mechanisms.

MATERIALS AND METHODS

Mice were administered Tan IIA 2 h before cecal ligation and puncture (CLP). Liver damage was evaluated by hematoxylin-eosin staining and changes in related serum factor levels. The expression of silent information regulator sirtuin 1 (SIRT1), Sestrin2, HO-1 and inflammatory cytokines was examined by immunohistochemistry or western blotting. LPS was used to induce the inflammatory response in vitro, and the activity of the related signaling pathway in response to Tan IIA was detected by western blotting. The SIRT1 inhibitor EX-527 and small interfering RNAs (siRNAs) were employed to determine the key roles of SIRT1 and Sestrin2 in Tan IIA's function.

RESULTS

We found that Tan IIA significantly improved the pathological changes and function of the liver, and alleviated liver damage in CLP mice. Additionally, SIRT1, Sestrin2, and HO-1 expression was significantly elevated after Tan IIA treatment compared with that in the CLP group both in vivo and in vitro, and Tan IIA treatment additionally suppressed pro-inflammatory cytokine release. However, inhibition of either SIRT1 or Sestrin2 remarkably abrogated the protective effects of Tan IIA. Most importantly, Sestrin2 appeared to function downstream of SIRT1 based on their expression changes after EX-527 or siRNA treatment.

CONCLUSION

Tan IIA inhibited sepsis/LPS-induced inflammation through the SIRT1/Sestrin2/HO-1 pathway, thereby protecting against sepsis-induced liver injury (SLI). This study suggests that Tan IIA has therapeutic potential against SLI and that the SIRT1/Sestrin2/HO-1 signaling pathway might be a viable target for SLI treatment.

Epigenetics-targeted drugs: current paradigms and future challenges

Epigenetics governs a chromatin state regulatory system through five key mechanisms: DNA modification, histone modification, RNA modification, chromatin remodeling, and non-coding RNA regulation. These mechanisms and their associated enzymes convey genetic information independently of DNA base sequences, playing essential roles in organismal development and homeostasis. Conversely, disruptions in epigenetic landscapes critically influence the pathogenesis of various human diseases. This understanding has laid a robust theoretical groundwork for developing drugs that target epigenetics-modifying enzymes in pathological conditions. Over the past two decades, a growing array of small molecule drugs targeting epigenetic enzymes such as DNA methyltransferase, histone deacetylase, isocitrate dehydrogenase, and enhancer of zeste homolog 2, have been thoroughly investigated and implemented as therapeutic options, particularly in oncology. Additionally, numerous epigenetics-targeted drugs are undergoing clinical trials, offering promising prospects for clinical benefits. This review delineates the roles of epigenetics in physiological and pathological contexts and underscores pioneering studies on the discovery and clinical implementation of epigenetics-targeted drugs. These include inhibitors, agonists, degraders, and multitarget agents, aiming to identify practical challenges and promising avenues for future research. Ultimately, this review aims to deepen the understanding of epigenetics-oriented therapeutic strategies and their further application in clinical settings.

Gastrodin attenuates diabetic cardiomyopathy characterized by myocardial fibrosis by inhibiting the KLK8-PAR1 signaling axis

BACKGROUND

Diabetic cardiomyopathy (DCM), characterized by myocardial fibrosis, is a major cause of mortality and morbidity in diabetic patients; the inhibition of cardiac fibrosis is a fundamental strategy for treating DCM. Gastrodin (GAS), a compound extracted from Gastrodia elata protects against DCM, but the molecular mechanism underlying its antifibrotic effect has not been elucidated.

METHODS

In vivo, the effects of GAS were investigated using C57BL/6 mice with DCM, which was induced by administering a high-sugar, high-fat (HSF) diet and streptozotocin (STZ). We assessed the cardiac function in these mice and detected histopathological changes in their hearts and the degree of cardiac fibrosis. In vitro, neonatal rat cardiac fibroblasts (CFs) were transformed into myofibroblasts by exposing them to high glucose combined with high palmitic acid (HG-PA), and CFs were induced by pEX-1 (pGCMV/MCS/EGFP/Neo) plasmid-mediated overexpression of KLK8, which contains the rat KLK8 gene. The KLK8 siRNA was knocked down to study the effects of GAS on CF differentiation, collagen synthesis, and cell migration by specific mechanisms of action of GAS.

RESULTS

GAS attenuated pathological changes in the hearts of DCM mice, rescued impaired cardiac function, and attenuated cardiac fibrosis. Additionally, the results of molecular docking analysis showed that GAS binds to kinin-releasing enzyme-related peptidase 8 (KLK8) to inhibit the increase in protease-activated receptor-1 (PAR-1), thus attenuating myocardial fibrosis. Specifically, GAS attenuated the transformation of neonatal rat CFs to myofibroblasts exposed to HG-PA. Overexpressing KLK8 promoted CF differentiation, collagen synthesis, and cell migration, and KLK8 siRNA attenuated HG-PA-induced CF differentiation, collagen synthesis, and cell migration. Further studies revealed that a PAR-1 antagonist, but not a PAR-2 antagonist, could attenuate CF differentiation, collagen synthesis, and cell migration. Additionally, GAS inhibited KLK8 upregulation and PAR1 activation, thus blocking the differentiation, collagen synthesis, and cell migration of HG-PA-exposed CFs and triggering TGF-β1/Smad3 signaling.

CONCLUSION

GAS alleviated pathological changes in the hearts of DCM model mice induced by an HSF diet combined with STZ. KLK8 mediated HG-PA-induced differentiation, collagen synthesis, and the migration of CFs. GAS attenuated the differentiation, collagen synthesis, and migration of CFs by inhibiting the KLK8-PAR1 signaling axis, a process in which TGF-β1 and Smad3 are involved.

Tanshinone IIA inhibits the apoptosis process of nerve cells by upshifting SIRT1 and FOXO3α protein and regulating anti- oxidative stress molecules and inflammatory factors in cerebral infarction model

BACKGROUND

As a prevalent cerebrovascular disorder, cerebral infarction (CI) has garnered extensive attention globally due to its high incidence and substantial fatality rate. Ischemia-reperfusion injury (IRI) exacerbates not only neuronal demise but also amplifies neural functional impairment. Tanshinone IIA (Tan IIA) has been identified to confer protection against IRI, yet the precise underlying mechanisms remain elusive. This work aimed to delve into the mechanistic role of Tan IIA in CI, with the goal of furnishing more distinct theoretical substantiation for its clinical application.

METHODS

Initially, a middle cerebral artery embolization model group (MCAO) model was established, followed by the categorization of rats into distinct groups based on different administration modes. Therapeutic effects were evaluated through indices including mortality rate, cerebral tissue water content, CI proportion, and neural functional scoring. Meanwhile, cellular apoptosis rates in hippocampal and cortical tissues, as well as levels of oxidative stress molecules (OSM), Sirtuin 1 (SIRT1), Forkhead box O3 (FOXO3α), and inflammatory factors, were examined to explore the mechanism of action.

RESULTS

This work revealed that within varying doses of Tan IIA groups, as dosage escalated, mortality rate, cerebral edema severity, CI proportion, and neural functional scoring gradually diminished. Notably, the 35 mg/kg dose group exhibited the most significant reductions, with decreases of 74.9%, 12.7%, 47.5%, and 54%, respectively. Cellular apoptosis rates in hippocampal and cortical tissues displayed a stepwise descending trend, with the 35 mg/kg dose group showcasing the largest reduction. SIRT1 and FOXO3α proteins exhibited a steady increase, with the 35 mg/kg dose group manifesting respective elevations of 87.9% and 65.5%, the highest among all groups. Antioxidant molecules glutathione (GSH) and superoxide dismutase (SOD) contents progressively increased, whereas malondialdehyde (MDA) and nitric oxide (NO) content decreased. The 35 mg/kg dose group recorded the highest increments of 49.1% and 58.1% for GSH and SOD content, while achieving the greatest reductions of 55.6% and 56.2% for MDA and NO content. Expression of inflammatory factors, namely tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), and interleukin-6 (IL-6), gradually declined, with reductions of 42.1%, 32.2%, and 29.1%, respectively, in the 35 mg/kg dose group, exhibiting drastic differences (p < 0.05).

CONCLUSION

In conclusion, this research elucidates that Tan IIA improves cerebral edema and neural function by elevating intracellular expression of SIRT1 and FOXO3α proteins, modulating OSM and inflammatory factors. These findings yielded robust experimental support for the potential use of Tan IIA as a therapeutic agent for CI.

Potential of natural drug modulation of endoplasmic reticulum stress in the treatment of myocardial injury

Myocardial injury (MI) is a common occurrence in clinical practice caused by various factors such as ischemia, hypoxia, infection, metabolic abnormalities, and inflammation. Such damages are characterized by a reduction in myocardial function and cardiomyocyte death that can result in dangerous outcomes such as cardiac failure and arrhythmias. An endoplasmic reticulum stress (ERS)-induced unfolded protein response (UPR) is triggered by several stressors, and its intricate signaling networks are instrumental in both cell survival and death. Cardiac damage frequently triggers ERS in response to different types of injuries and stress. High levels of ERS can exacerbate myocardial damage by inducing necrosis and apoptosis. To target ERS in MI prevention and treatment, current medical research is focused on identifying effective therapy approaches. Traditional Chinese medicine (TCM) is frequently used because of its vast range of applications and low risk of adverse effects. Various studies have demonstrated that active components of Chinese medicines, including polyphenols, saponins, and alkaloids, can reduce myocardial cell death, inflammation, and modify the ERS pathway, thus preventing and mitigating cardiac injury. Thus, this paper aims to provide a new direction and scientific basis for targeting ERS in MI prevention and treatment. We specifically summarize recent research progress on the regulation mechanism of ERS in MI by active ingredients of TCM.

The Role of Natural Products in Diabetic Retinopathy

Diabetic retinopathy (DR) is one of the most severe complications of diabetes mellitus and potentially leads to significant visual impairment and blindness. The complex mechanisms involved in the pathological changes in DR make it challenging to achieve satisfactory outcomes with existing treatments. Diets conducive to glycemic control have been shown to improve outcomes in diabetic patients, thus positioning dietary interventions as promising avenues for DR treatment. Investigations have demonstrated that natural products (NPs) may effectively manage DR. Many types of natural compounds, including saponins, phenols, terpenoids, flavonoids, saccharides, alkaloids, and vitamins, have been shown to exert anti-inflammatory, antioxidant, anti-neovascular, and antiapoptotic effects in vivo and in vitro. Nevertheless, the clinical application of NPs still faces challenges, such as suboptimal specificity, poor bioavailability, and a risk of toxicity. Prospective clinical studies are imperative to validate the therapeutic potential of NPs in delaying or preventing DR.

Roles of Sirt1 and its modulators in diabetic microangiopathy: A review

Diabetic vascular complications include diabetic macroangiopathy and diabetic microangiopathy. Diabetic microangiopathy is characterised by impaired microvascular endothelial function, basement membrane thickening, and microthrombosis, which may promote renal, ocular, cardiac, and peripheral system damage in diabetic patients. Therefore, new preventive and therapeutic strategies are urgently required. Sirt1, a member of the nicotinamide adenine dinucleotide-dependent histone deacetylase class III family, regulates different organ growth and development, oxidative stress, mitochondrial function, metabolism, inflammation, and aging. Sirt1 is downregulated in vascular injury and microangiopathy. Moreover, its expression and distribution in different organs correlate with age and play critical regulatory roles in oxidative stress and inflammation. This review introduces the background of diabetic microangiopathy and the main functions of Sirt1. Then, the relationship between Sirt1 and different diabetic microangiopathies and the regulatory roles mediated by different cells are described. Finally, we summarize the modulators that target Sirt1 to ameliorate diabetic microangiopathy as an essential preventive and therapeutic measure for diabetic microangiopathy. In conclusion, targeting Sirt1 may be a new therapeutic strategy for diabetic microangiopathy.

D-pinitol alleviates diabetic cardiomyopathy by inhibiting the optineurin-mediated endoplasmic reticulum stress and glycophagy signaling pathway

Diabetic cardiomyopathy (DCM) is an important complication resulting in heart failure and death of diabetic patients. However, there is no effective drug for treatments. This study investigated the effect of D-pinitol (DP) on cardiac injury using diabetic mice and glycosylation injury of cardiomyocytes and its molecular mechanisms. We established the streptozotocin-induced SAMR1 and SAMP8 mice and DP (150 mg/kg/day) intragastrically and advanced glycation end-products (AGEs)-induced H9C2 cells. H9C2 cells were transfected with optineurin (OPTN) siRNA and overexpression plasmids. The metabolic disorder indices, cardiac dysfunction, histopathology, immunofluorescence, western blot, and immunoprecipitation were investigated. Our results showed that DP reduced the blood glucose and AGEs, and increased the expression of heart OPTN in diabetic mice and H9C2 cells, thereby inhibiting the endoplasmic reticulum stress (GRP78, CHOP) and glycophagy (STBD1, GABARAPL1), and alleviating the myocardial apoptosis and fibrosis of DCM. The expression of filamin A as an interaction protein of OPTN downregulated by AGEs decreased OPTN abundance. Moreover, OPTN siRNA increased the expression of GRP78, CHOP, STBD1, and GABARAPL1 and inhibited the expression of GAA via GSK3β phosphorylation and FoxO1. DP may be helpful to treat the onset of DCM. Targeting OPTN with DP could be translated into clinical application in the fighting against DCM.

Maintaining the Mitochondrial Quality Control System Was a Key Event of Tanshinone IIA against Deoxynivalenol-Induced Intestinal Toxicity

Deoxynivalenol (DON) is the one of the most common mycotoxins, widely detected in various original foods and processed foods. Tanshinone IIA (Tan IIA) is a fat-soluble diterpene quinone extracted from Salvia miltiorrhiza Bunge, which has multi-biological functions and pharmacological effects. However, whether Tan IIA has a protective effect against DON-induced intestinal toxicity is unknown. In this study, the results showed Tan IIA treatment could attenuate DON-induced IPEC-J2 cell death. DON increased oxidation product accumulation, decreased antioxidant ability and disrupted barrier function, while Tan IIA reversed DON-induced barrier function impairment and oxidative stress. Furthermore, Tan IIA dramatically improved mitochondrial function via mitochondrial quality control. Tan IIA could upregulate mitochondrial biogenesis and mitochondrial fusion as well as downregulate mitochondrial fission and mitochondrial unfolded protein response. In addition, Tan IIA significantly attenuated mitophagy caused by DON. Collectively, Tan IIA presented a potential protective effect against DON toxicity and the underlying mechanisms were involved in mitochondrial quality control-mediated mitophagy.

SIRT1 regulates endoplasmic reticulum stress-related organ damage

Endoplasmic reticulum (ER) stress plays a key role in the pathogenesis of several organ damages. Studies show that excessive ER stress (ERS) can destroy cellular homeostasis, causing cell damage and physiological dysfunction in various organs. In recent years, Sirtuin1 (SIRT1) has become a research hotspot on ERS. Increasing evidence suggests that SIRT1 plays a positive role in various ERS-induced organ damage via multiple mechanisms, including inhibiting cellular apoptosis and promoting autophagy. SIRT1 can also alleviate liver, heart, lung, kidney, and intestinal damage by inhibiting ERS. We discuss the possible mechanism of SIRT1, explore potential therapeutic targets of diseases, and provide a theoretical basis for treating ERS-related diseases.

Qiliqiangxin: A multifaceted holistic treatment for heart failure or a pharmacological probe for the identification of cardioprotective mechanisms?

The active ingredients in many traditional Chinese medicines are isoprene oligomers with a diterpenoid or triterpenoid structure, which exert cardiovascular effects by signalling through nutrient surplus and nutrient deprivation pathways. Qiliqiangxin (QLQX) is a commercial formulation of 11 different plant ingredients, whose active compounds include astragaloside IV, tanshione IIA, ginsenosides (Rb1, Rg1 and Re) and periplocymarin. In the QUEST trial, QLQX reduced the combined risk of cardiovascular death or heart failure hospitalization (hazard ratio 0.78, 95% confidence interval 0.68-0.90), based on 859 events in 3119 patients over a median of 18.2 months; the benefits were seen in patients taking foundational drugs except for sodium-glucose cotransporter 2 (SGLT2) inhibitors. Numerous experimental studies of QLQX in diverse cardiac injuries have yielded highly consistent findings. In marked abrupt cardiac injury, QLQX mitigated cardiac injury by upregulating nutrient surplus signalling through the PI3K/Akt/mTOR/HIF-1α/NRF2 pathway; the benefits of QLQX were abrogated by suppression of PI3K, Akt, mTOR, HIF-1α or NRF2. In contrast, in prolonged measured cardiac stress (as in chronic heart failure), QLQX ameliorated oxidative stress, maladaptive hypertrophy, cardiomyocyte apoptosis, and proinflammatory and profibrotic pathways, while enhancing mitochondrial health and promoting glucose and fatty acid oxidation and ATP production. These effects are achieved by an action of QLQX to upregulate nutrient deprivation signalling through SIRT1/AMPK/PGC-1α and enhanced autophagic flux. In particular, QLQX appears to enhance the interaction of PGC-1α with PPARα, possibly by direct binding to RXRα; silencing of SIRT1, PGC-1α and RXRα abrogated the favourable effects of QLQX in the heart. Since PGC-1α/RXRα is also a downstream effector of Akt/mTOR signalling, the actions of QLQX on PGC-1α/RXRα may explain its favourable effects in both acute and chronic stress. Intriguingly, the individual ingredients in QLQX - astragaloside IV, ginsenosides, and tanshione IIA - share QLQX's effects on PGC-1α/RXRα/PPARα signalling. QXQL also contains periplocymarin, a cardiac glycoside that inhibits Na+ -K+ -ATPase. Taken collectively, these observations support a conceptual framework for understanding the mechanism of action for QLQX in heart failure. The high likelihood of overlap in the mechanism of action of QLQX and SGLT2 inhibitors requires additional experimental studies and clinical trials.

Chinese herbal medicine and active ingredients for diabetic cardiomyopathy: molecular mechanisms regulating endoplasmic reticulum stress

Background: Diabetic cardiomyopathy (DCM) is one of the serious microvascular complications of diabetes mellitus. It is often associated with clinical manifestations such as arrhythmias and heart failure, and significantly reduces the quality of life and years of survival of patients. Endoplasmic reticulum stress (ERS) is the removal of unfolded and misfolded proteins and is an important mechanism for the maintenance of cellular homeostasis. ERS plays an important role in the pathogenesis of DCM by causing cardiomyocyte apoptosis, insulin resistance, calcium imbalance, myocardial hypertrophy and fibrosis. Targeting ERS is a new direction in the treatment of DCM. A large number of studies have shown that Chinese herbal medicine and active ingredients can significantly improve the clinical outcome of DCM patients through intervention in ERS and effects on myocardial structure and function, which has become one of the hot research directions. Purpose: The aim of this review is to elucidate and summarize the roles and mechanisms of Chinese herbal medicine and active ingredients that have the potential to modulate endoplasmic reticulum stress, thereby contributing to better management of DCM. Methods: Databases such as PubMed, Web of Science, China National Knowledge Internet, and Wanfang Data Knowledge Service Platform were used to search, analyze, and collect literature, in order to review the mechanisms by which phytochemicals inhibit the progression of DCM by targeting the ERS and its key signaling pathways. Keywords used included "diabetic cardiomyopathy" and "endoplasmic reticulum stress." Results: This review found that Chinese herbs and their active ingredients can regulate ERS through IRE1, ATF6, and PERK pathways to reduce cardiomyocyte apoptosis, ameliorate myocardial fibrosis, and attenuate myocardial hypertrophy for the treatment of DCM. Conclusion: A comprehensive source of information on potential ERS inhibitors is provided in this review. The analysis of the literature suggests that Chinese herbal medicine and its active ingredients can be used as potential drug candidates for the treatment of DCM. In short, we cannot ignore the role of traditional Chinese medicine in regulating ERS and treating DCM, and look forward to more research and new drugs to come.

1,8-Cineole ameliorates diabetic retinopathy by inhibiting retinal pigment epithelium ferroptosis via PPAR-γ/TXNIP pathways

1,8-Cineole, the main component of volatile oil in aromatic plants, has diverse pharmacological properties, including antioxidant, anti-inflammatory, and anti-cancer properties. Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus (DM). Here, we investigated the protective effect of 1,8-cineole on DR and found that 1,8-cineole treatment could alter the expression of several genes in both high glucose (HG)-induced ARPE-19 cells and retinal tissues of DM mice, as well as inhibit ferroptosis. Subsequent investigations into the molecular mechanisms underlying this inhibition revealed that expression of thioredoxin-interacting protein (TXNIP) was significantly upregulated while that of peroxisome proliferator-activated receptor γ (PPAR-γ) was significantly downregulated in HG-induced ARPE-19 cells, and treatment with 1,8-cineole could effectively reverse these changes. Treatment with a PPAR-γ pharmacological agonist (rosiglitazone), alone or combined with 1,8-cineole, significantly inhibited the transcription of TXNIP and ferroptosis in HG-induced ARPE-19 cells. Conversely, pretreatment with GW9662, a PPAR-γ inhibitor, upregulated the transcription and expression of TXNIP in HG-induced ARPE-19 cells; 1,8-cineole failed to reverse this upregulated expression. To explore these relationships, we constructed a PPAR-γ adenovirus shRNA to elucidate the effect of 1,8-cineole on the negative regulation of TXNIP by PPAR-γ. Taken together, the present findings indicate that HG-induced ferroptosis in retinal tissue plays an essential role in the pathogenesis of DR, which can be ameliorated by 1,8-cineole.