Tetrandrine cardioprotection in ischemia–reperfusion (I/R) injury via JAK3/STAT3/Hexokinase II

Advances in glioblastoma multiforme: Integrating therapy and pathology perspectives

Glioblastoma, a highly lethal form of brain cancer, is characterized by its aggressive growth and resistance to conventional treatments, often resulting in limited survival. The response to therapy is notably influenced by various patient-specific genetic factors, underscoring the disease's complexity. Despite the utilization of diverse treatment modalities such as surgery, radiation, and chemotherapy, many patients experience local relapse, emphasizing the critical need for improved therapeutic strategies to effectively target these formidable tumors. Recent years have witnessed a surge in interest in natural products derived from plants, particularly alkaloids, for their potential anticancer effects. Alkaloids have shown promise in cancer chemotherapy by selectively targeting crucial signaling pathways implicated in tumor progression and survival. Specifically, they modulate the NF-κB and MAPK pathways, resulting in reduced tumor growth and altered gene expression across various cancer types. Additionally, alkaloids exhibit the capacity to induce cell cycle arrest, further impeding tumor proliferation in several malignancies. This review aims to delineate recent advances in understanding the pathology of glioblastoma multiforme (GBM) and to explore the potential therapeutic implications of alkaloids in managing this deadly disease. By segregating discussions on GBM pathology from those on alkaloid-based therapies, we provide a structured overview of the current challenges in GBM treatment and the promising opportunities presented by alkaloid-based interventions. Furthermore, we briefly discuss potential future directions in GBM research and therapy beyond alkaloids, including emerging treatment modalities or areas of investigation that hold promise for improving patient outcomes. In conclusion, our efforts offer hope for enhanced outcomes and improved quality of life for GBM patients through alkaloid-based therapies. By integrating insights from pathology and therapeutic perspectives, we underscore the significance of a comprehensive approach in addressing this devastating disease.

The Role of the JAK-STAT Signaling Pathway in the Protective Effects of Hepatic Ischemia Post-conditioning Against the Injury Induced by Ischemia/Reperfusion in the Rat Liver

Purpose

Hepatic ischemic post-conditioning (IPOC) is shown to protect the liver from injury induced by ischemia/reperfusion (IR). However, the mechanism underlying this protection has remained elusive. The present study aimed to investigate the role of the interleukin 6-Janus kinase-signal transducers and activators of transcription (IL-6-JAK-STAT) pathway in the protective effect of hepatic IPOC against the IR-induced injury in the liver.

Methods

Twenty-five rats were randomly divided into 5 groups of (1) sham-operated, (2) IR, (3) IR+hepatic IPOC, (4) IR+tofacitinib (TOFA), and (5) IR+TOFA+hepatic IPOC. The changes induced by IR and the effects of different treatments were assessed by enzyme release, histopathological observations, the serum level of IL-6, and the occurrence of apoptosis detected via the expression of the Bax/Bcl-2 ratio.

Results

The hepatic IPOC improved the liver injury induced by IR as shown by histological changes, reduction of IL-6 level, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) compared to the IR group (P<0.001, P<0.05, P<0.05, respectively). There was also downregulation of the Bax/Bcl2 ratio in the rats exposed to IR+hepatic IPOC compared with those in the IR group (P<0.05). However, TOFA, an inhibitor of JAK-STAT activity, inhibited the protective effect of hepatic IPOC.

Conclusion

It suggests that the protective effect of hepatic IPOC against IR-induced injury may be mediated by activating the IL-6-JAK-STAT pathway.

Tetrandrine downregulates TRPV2 expression to ameliorate myocardial ischemia/reperfusion injury in rats via regulation of cardiomyocyte apoptosis, calcium homeostasis and mitochondrial function

Our previous study has indicated that tetrandrine (TET) can target miR-202-5p to repress the activation of transient receptor potential vanilloid type 2 (TRPV2), eventually ameliorating the progression of myocardial ischemia/reperfusion injury (MI/RI). This study is aimed to further ascertain the detailed mechanisms between TET and TRPV2 in MI/RI pathogenesis. Here, a myocardial I/R injury rat model and a hypoxia-reoxygenation (H/R) model in rat myocardial cell line (H9C2 cells) were established. We reported that pronounced upregulation of TRPV2 was observed in I/R rats and H/R-induced H9C2 cells. Silencing of TRPV2 could improve cardiac function and myocardial injury, reduced infarction size, and promoted cardiomyocyte proliferation in I/R rats. In I/R rats or H/R-induced H9C2 cells, cardiomyocyte apoptosis was inhibited by knocking-down TRPV2. Meanwhile, the silenced TRPV2 or TET treatment ameliorated the damaged mitochondrial structure, mitigated ROS generation, restored the impaired ΔΨM, inhibited mPTP opening and alleviated Ca2+ overload in H/R-induced H9C2 cells. The results obtained from the overexpression of TRPV2 were contrary to those depicted above. Moreover, TET could downregulate TRPV2 expression, while the overexpression of TRPV2 could reverse the above protective effects of TET in H/R-induced H9C2 cells. The results indicated that TET may function as a TRPV2 blocking agent, thereby attenuating the progression of MI/RI through modulation of cardiomyocyte apoptosis, calcium homeostasis and mitochondrial function. These findings offer a theoretical foundation for potential clinical application of TET therapy in patients with MI/RI.

Research progress on pharmacological effects and mechanisms of cepharanthine and its derivatives

Cepharanthine (CEP) is a bisbenzylisoquinoline alkaloid compound found in plants of the Stephania genus, which has biological functions such as regulating autophagy, inhibiting inflammation, oxidative stress, and apoptosis. It is often used for the treatment of inflammatory diseases, viral infections, cancer, and immune disorders and has great clinical translational value. However, there is no detailed research on its specific mechanism and dosage and administration methods, especially clinical research is limited. In recent years, CEP has shown significant effects in the prevention and treatment of COVID-19, suggesting its potential medicinal value waiting to be discovered. In this article, we comprehensively introduce the molecular structure of CEP and its derivatives, describe in detail the pharmacological mechanisms of CEP in various diseases, and discuss how to chemically modify and design CEP to improve its bioavailability. In summary, this work will provide a reference for further research and clinical application of CEP.

Lnc-PXMP4-2-4 alleviates myocardial cell damage by activating the JAK2/STAT3 signaling pathway

PURPOSE

The aim of this study was to investigate the protective effect of long non-coding lnc-PXMP4-2-4 on myocardial cell damage caused by acute myocardial infarction (AMI).

METHODS

Peripheral blood mononuclear cells (PBMC) were collected from 24 patients with AMI on the day of admission, the first day after percutaneous coronary intervention (PCI) and the third day after surgery, and 24 patients with clinical control group. Real-time quantitative PCR(QRT-PCR) was used to detect the expression of related genes. Then in human cardiomyocytes (AC16), Cell Counting Kit-8 (CCK-8) was used to determine cell viability, lactate dehydrogenase release assay (LDH) was used to determine the release of lactate dehydrogenase, PCR was used to detect the expression of genes, cell death was detected by flow cytometry, and the expression of related proteins was measured by Western blot. The effect of lnc-PXMP4-2-4 was further studied by silencing and overexpressing lnc-PXMP4-2-4.

RESULTS

Compared with clinical control group, the expression of lnc-PXMP4-2-4 in PBMC of AMI patients was significantly higher than it. Compared with pre-operation, the expression of lnc-PXMP4-2-4 was significantly up-regulated on day 1 after PCI, and recovered to pre-operation level on day 3 after surgery. In AC16 cells, lnc-PXMP4-2-4 inhibited the proliferation of AC16, promoted the release of LDH and increased cell death, aggravated the cardiomyocyte injury caused by H2O2, and inhibited the expression of JAK2 and STAT3 mRNA and protein. The up-regulation of lnc-PXMP-4-2-4 had the opposite effect. In addition, the inhibition of the signal pathway by JAK2/STAT3 pathway inhibitor AG490 partially weakened the enhanced viability of AC16 cells, decreased LDH release and apoptosis induced by lnc-PXMP4-2-4 overexpression, increased Bcl-2 expression and down-regulated Bax expression.

CONCLUSION

Therefore, we conclude that lnc-PXMP4-2-4 protects cardiomyocytes from injury by activating the JAK2/STAT3 signaling pathway.

Chinese herbal medicine for the treatment of cardiovascular diseases ─ targeting cardiac ion channels

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality, imposing an increasing global health burden. Cardiac ion channels (voltage-gated Na_V, Ca_V, K_Vs, and others) synergistically shape the cardiac action potential (AP) and control the heartbeat. Dysfunction of these channels, due to genetic mutations, transcriptional or post-translational modifications, may disturb the AP and lead to arrhythmia, a major risk for CVD patients. Although there are five classes of anti-arrhythmic drugs available, they can have varying levels of efficacies and side effects on patients, possibly due to the complex pathogenesis of arrhythmias. As an alternative treatment option, Chinese herbal remedies have shown promise in regulating cardiac ion channels and providing anti-arrhythmic effects. In this review, we first discuss the role of cardiac ion channels in maintaining normal heart function and the pathogenesis of CVD, then summarize the classification of Chinese herbal compounds, and elaborate detailed mechanisms of their efficacy in regulating cardiac ion channels and in alleviating arrhythmia and CVD. We also address current limitations and opportunities for developing new anti-CVD drugs based on Chinese herbal medicines.

Progress on structural modification of Tetrandrine with wide range of pharmacological activities

Tetrandrine (Tet), derived from the traditional Chinese herb Fangji, is a class of natural alkaloids with the structure of bisbenzylisoquinoline, which has a wide range of physiological activities and significant pharmacfological effects. However, studies and clinical applications have revealed a series of drawbacks such as its poor water solubility, low bioavailability, and the fact that it can be toxic to humans. The results of many researchers have confirmed that chemical structural modifications and nanocarrier delivery can address the limited application of Tet and improve its efficacy. In this paper, we summarize the anti-tumor efficacy and mechanism of action, anti-inflammatory efficacy and mechanism of action, and clinical applications of Tet, and describe the progress of Tet based on chemical structure modification and nanocarrier delivery, aiming to explore more diverse structures to improve the pharmacological activity of Tet and provide ideas to meet clinical needs.

Mitochondrial Damage in Myocardial Ischemia/Reperfusion Injury and Application of Natural Plant Products

Ischemic heart disease (IHD) is currently one of the leading causes of death among cardiovascular diseases worldwide. In addition, blood reflow and reperfusion paradoxically also lead to further death of cardiomyocytes and increase the infarct size. Multiple evidences indicated that mitochondrial function and structural disorders were the basic driving force of IHD. We summed up the latest evidence of the basic associations and underlying mechanisms of mitochondrial damage in the event of ischemia/reperfusion (I/R) injury. This review then reviewed natural plant products (NPPs) which have been demonstrated to mitochondria-targeted therapeutic effects during I/R injury and the potential pathways involved. We realized that NPPs mainly maintained the integrality of mitochondria membrane and ameliorated dysfunction, such as improving abnormal mitochondrial calcium handling and inhibiting oxidative stress, so as to protect cardiomyocytes during I/R injury. This information will improve our knowledge of mitochondrial biology and I/R-induced injury's pathogenesis and exhibit that NPPs hold promise for translation into potential therapies that target mitochondria.

Protective effects of natural products against myocardial ischemia/reperfusion: Mitochondria-targeted therapeutics

Patients with ischemic heart disease receiving reperfusion therapy still need to face left ventricular remodeling and heart failure after myocardial infarction. Reperfusion itself paradoxically leads to further cardiomyocyte death and systolic dysfunction. Ischemia/reperfusion (I/R) injury can eliminate the benefits of reperfusion therapy in patients and causes secondary myocardial injury. Mitochondrial dysfunction and structural disorder are the basic driving force of I/R injury. We summarized the basic relationship and potential mechanisms of mitochondrial injury in the development of I/R injury. Subsequently, this review summarized the natural products (NPs) that have been proven to targeting mitochondrial therapeutic effects during I/R injury in recent years and related cellular signal transduction pathways. We found that these NPs mainly protected the structural integrity of mitochondria and improve dysfunction, such as reducing mitochondrial division and fusion abnormalities, improving mitochondrial Ca²⁺ overload and inhibiting reactive oxygen species overproduction, thereby playing a role in protecting cardiomyocytes during I/R injury. This data would deepen the understanding of I/R-induced mitochondrial pathological process and suggested that NPs are expected to be transformed into potential therapies targeting mitochondria.

Research Progress on Natural Products’ Therapeutic Effects on Atrial Fibrillation by Regulating Ion Channels

Antiarrhythmic drugs (AADs) have a therapeutic effect on atrial fibrillation (AF) by regulating the function of ion channels. However, several adverse effects and high recurrence rates after drug withdrawal seriously affect patients’ medication compliance and clinical prognosis. Thus, safer and more effective drugs are urgently needed. Active components extracted from natural products are potential choices for AF therapy. Natural products like Panax notoginseng (Burk.) F.H. Chen, Sophora flavescens Ait., Stephania tetrandra S. Moore., Pueraria lobata (Willd.) Ohwi var. thomsonii (Benth.) Vaniot der Maesen., and Coptis chinensis Franch. have a long history in the treatment of arrhythmia, myocardial infarction, stroke, and heart failure in China. Based on the classification of chemical structures, this article discussed the natural product components’ therapeutic effects on atrial fibrillation by regulating ion channels, connexins, and expression of related genes, in order to provide a reference for development of therapeutic drugs for atrial fibrillation.

Combination of tetrandrine and 3-n-butylphthalide protects against cerebral ischemia-reperfusion injury via ATF2/TLR4 pathway

OBJECTIVE

Cerebral infarction (CI) is the mayor reason of death in China. Reperfusion is the only immediate treatment for acute cerebral infarction. However, blood reperfusion recovery may cause ischemia-reperfusion (I/R) injuries. The purpose of this study was to investigate the effects of Tetrandrine (TTD) and 3-n-Butylphthalide (NBP) on cerebral I/R injury.

MATERIALS AND METHODS

I/R was used to establish CI model in vivo. TTD was performed to analyze cerebral infarction volume. OGD was applied to establish CI model in vitro. Flow cytometry and TUNEL assays were utilized to determine the cell death. ELISA was conducted to determine the release of cytokines. mRNA and protein expressions were detected using qRT-PCR and western blot.

RESULTS

We found that NBP + TTD treatment significantly reduced cerebral infarction volume and inhibited the death of neurons in vivo. Moreover, NBP + TTD treatment suppressed the apoptosis and inflammatory response of neurons in vitro. Additionally, NBP + TTD suppressed the expression of activator transcription factor 2 (ATF2). However, overexpression of ATF2 contributed to the degeneration of neurons. Moreover, ATF2 transcriptionally activated Toll-like receptor 4 (TLR4). NBP + TTD inactivated ATF2/TLR4 signaling.

CONCLUSIONS

Taken together, TTD combined with NBP protected against cerebral infarction by inhibiting the inflammatory response and neuronal cell apoptosis via inactivating ATF2/TLR4 signaling pathways. This may provide an alternative for I/R injury.

Tetrandrine Ameliorates Myocardial Ischemia Reperfusion Injury through miR-202-5p/TRPV2

Objective

This study is aimed at investigating the therapeutic effects of tetrandrine (Tet) on myocardial ischemia reperfusion (I/R) injury and probe into underlying molecular mechanism.

Methods

H9C2 cells were divided into hypoxia/oxygenation (H/R) group, H/R+Tet group, H/R+Tet+negative control (NC) group, and H/R+Tet+miR-202-5p inhibitor group. RT-qPCR was utilized to monitor miR-202-5p and TRPV2 expression, and TRPV2 protein expression was detected via western blot and immunohistochemistry in H9C2 cells. Cardiomyocyte apoptosis was evaluated through detection of apoptosis-related markers and flow cytometry. Furthermore, myocardial enzyme levels were detected by ELISA. Rats were randomly separated into sham operation group, I/R group, I/R+Tet group (50 mg/kg), I/R+Tet+NC group, and I/R+Tet+miR-202-5p inhibitor group. miR-202-5p and TRPV2 mRNA expression was assessed by RT-qPCR. TRPV2 protein expression was detected through western blot and immunohistochemistry in myocardial tissues. Apoptotic levels were assessed via apoptosis-related proteins and TUNEL. Pathological changes were observed by H&E staining. Myocardial infarction size was examined by Evans blue-TCC staining.

Results

Abnormally expressed miR-202-5p as well as TRPV2 was found in H/R H9C2 cells and myocardial tissues of I/R rats, which was ameliorated following Tet treatment. Tet treatment significantly suppressed H/R- or I/R-induced cardiomyocyte apoptosis. ELISA results showed that CK-MB and LDH levels were lowered by Tet treatment in H/R H9C2 cells and serum of I/R rats. H&E staining indicated that Tet reduced myocardial injury in I/R rats. Also, myocardial infarction size was lowered by Tet treatment. The treatment effects of Tet were altered following cotreatment with miR-202-5p inhibitor.

Conclusion

Our findings revealed that Tet may ameliorate myocardial I/R damage via targeting the miR-202-5p/TRPV2 axis.

Tetrandrine attenuates left ventricular dysfunction in rats with myocardial infarction

The present study aimed to determine whether tetrandrine could attenuate left ventricular dysfunction and remodeling in rats with myocardial infarction. Sprague-Dawley rats were randomly divided into six groups (n=5/group) as follows: i) Healthy control group; ii) sham operation group; iii) myocardial infarction model group; iv) myocardial infarction + low-dose tetrandrine group (10 mg/kg); v) myocardial infarction + medium-dose tetrandrine group (50 mg/kg); and vi) myocardial infarction + high-dose tetrandrine group (80 mg/kg). Left ventricular end-diastolic diameter (LVIDd), left ventricular end-systolic diameter (LVIDs), ejection fraction (EF%) and left ventricular fractional shortening rate (FS%) were measured using ultrasonography. The pathological changes were observed by hematoxylin and eosin (H&E) staining. Left ventricular tissue section TUNEL staining was also performed. Furthermore, the triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL) and low-density lipoprotein (LDL) in the arterial blood were examined by biochemical testing. Expression levels of intracellular Ca²⁺ homeostasis-related proteins including ryanodine receptor calmodulin, CaM-dependent protein kinase IIδ, protein kinase A, FK506 binding protein 12.6 were measured using western blot analysis. Ultrasonography results showed that in the myocardial infarction model rats, the levels of LVIDd and LVIDs were significantly higher; however, the levels of EF% and FS% were lower compared with those in the sham operation group, which was alleviated by tetrandrine. H&E results showed that tetrandrine alleviated the pathological characteristics of myocardial infarction model rats. Furthermore, tetrandrine significantly inhibited myocardial cell apoptosis in rats with myocardial infarction. Tetrandrine significantly inhibited the levels of TG, TC and LDL and increased the levels of HDL in the arterial blood of rats with myocardial infarction. These findings revealed that tetrandrine could attenuate left ventricular dysfunction in rats with myocardial infarction, which might be associated with intracellular Ca²⁺ homeostasis.

Correlation between Mitochondrial Dysfunction, Cardiovascular Diseases, and Traditional Chinese Medicine

Cardiovascular disease (CVD) is the number one threat that seriously endangers human health. However, the mechanism of their occurrence is not completely clear. Increasing studies showed that mitochondrial dysfunction is closely related to CVD. Possible causes of mitochondrial dysfunction include oxidative stress, Ca²⁺ disorder, mitochondrial DNA mutations, and reduction of mitochondrial biosynthesis, all of which are closely related to the development of CVD. At present, traditional Chinese medicine (TCM) is widely used in the treatment of CVD. TCM has the therapeutic characteristics of multitargets and multipathways. Studies have shown that TCM can treat CVD by protecting mitochondrial function. Via systematic literature review, the results show that the specific mechanisms include antioxidant stress, regulation of calcium homeostasis, antiapoptosis, and regulation of mitochondrial biosynthesis. This article describes the relationship between mitochondrial dysfunction and CVD, summarizes the TCM commonly used for the treatment of CVD in recent years, and focuses on the regulatory effect of TCM on mitochondrial function.

Tetrandrine attenuates hyperoxia-induced lung injury in newborn rats via NF-κB p65 and ERK1/2 pathway inhibition

Background

Bronchopulmonary dysplasia (BPD) is an important cause of respiratory illness in preterm newborns that results in significant morbidity and mortality. Hyperoxia is a critical factor in the pathogenesis of BPD, hyperoxia-induced lung injury model has similar pathological manifestations as human BPD. Tetrandrine (Tet) is known to suppress oxidative stress, apoptosis and inflammation. Thus it has been used to prevent organ injuries. However, the protective effect of Tet against hyperoxia-induced lung injury in newborn rats has not been reported.

Methods

A hyperoxia-induced lung injury model was established using newborn rats exposed to high O₂ levels. The models were treated with various concentrations of Tet, and a lung function test was conducted. Then, the lung tissues and blood were collected to detect the effect of Tet on cell apoptosis, inflammatory response, and fibrosis. The effect of Tet on nuclear factor-kappa B (NF-κB) and extracellular signal-regulated kinase1/2 (ERK1/2) pathways was also determined.

Results

Lung function was decreased in hyperoxia-induced rats, and Tet could reverse this inhibiting effect. For oxidative stress, Tet caused an increase in the levels of antioxidant enzymes. The apoptosis rate and apoptosis-related proteins were decreased in hyperoxia-induced rats after Tet treatment. Additionally, Tet treatment could reduce inflammatory factor levels, while increasing CD4⁺IFN-γ⁺ T cell levels and decreasing CD4⁺IL-4⁺ T cell levels. Tet treatment was also able to inhibit the expression of fibrosis-related markers and NF-κB and ERK1/2 pathways.

Conclusions

Tet demonstrated potent activity against hyperoxia-induced lung injury in newborn rats through NF-κB and ERK1/2 pathway inhibition.

Tetrandrine: a review of its anticancer potentials, clinical settings, pharmacokinetics and drug delivery systems

OBJECTIVES

Tetrandrine, a natural bisbenzylisoquinoline alkaloid, possesses promising anticancer activities on diverse tumours. This review provides systematically organized information on cancers of tetrandrine in vivo and in vitro, discuss the related molecular mechanisms and put forward some new insights for the future investigations.

KEY FINDINGS

Anticancer activities of tetrandrine have been reported comprehensively, including lung cancer, colon cancer, bladder cancer, prostate cancer, ovarian cancer, gastric cancer, breast cancer, pancreatic cancer, cervical cancer and liver cancer. The potential molecular mechanisms corresponding to the anticancer activities of tetrandrine might be related to induce cancer cell apoptosis, autophagy and cell cycle arrest, inhibit cell proliferation, migration and invasion, ameliorate metastasis and suppress tumour cell growth. Pharmaceutical applications of tetrandrine combined with nanoparticle delivery system including liposomes, microspheres and nanoparticles with better therapeutic efficiency have been designed and applied encapsulate tetrandrine to enhance its stability and efficacy in cancer treatment.

SUMMARY

Tetrandrine was proven to have definite antitumour activities. However, the safety, bioavailability and pharmacokinetic parameter studies on tetrandrine are very limited in animal models, especially in clinical settings. Our present review on anticancer potentials of tetrandrine would be necessary and highly beneficial for providing guidelines and directions for further research of tetrandrine.

Tetrandrine alleviates cerebral ischemia/reperfusion injury by suppressing NLRP3 inflammasome activation via Sirt-1

Background & Aims

Tetrandrine (Tet) has been reported to have anti-inflammatory effects and protect from the ischemic strokes. The NLRP3 inflammasome plays a key role in cerebral ischemia/reperfusion (I/R)-induced inflammatory lesions. However, the molecular mechanisms of Tet related to the progression of cerebral ischemia are still unclear. Therefore, the aim of this study was to investigate the possible effects of Tet on cerebral ischemia and the related mechanisms involved in NLRP3 inflammasome.

Methods

C57BL/6J mice used as a cerebral I/R injury model underwent middle cerebral artery occlusion (MCAO) for 2 h following reperfusion for 24 h. Tet (30 mg/kg/day, i.p.) was administered for seven days and 30 min before and after MCAO. Their brain tissues were evaluated for NLRP3 inflammasome and Sirtuin-1 (Sirt-1) expression. An intracerebroventricular injection of Sirt-1 siRNA was administered to assess the activation of the NLRP3 inflammasome.

Results

Tet significantly reduced the neurological deficits, infarction volume, and cerebral water content in MCAO mice. Moreover, it inhibited I/R-induced over expression of NLRP3, cleaved caspase-1, interleukin (IL)-1β, IL-18, and Sirt-1. Sirt-1 knockdown with siRNA greatly blocked the Tet-induced reduction of neurological severity score and infarct volume, and reversed the inhibition of NLRP3 inflammasome activation.

Conclusion

Our results demonstrate that Tet has benefits for cerebral I/R injury, which are partially related to the suppression of NLRP3 inflammasome activation via upregulating Sirt-1.

Antitumor activity of tetrandrine citrate in human glioma U87 cells in vitro and in vivo

Since the current methods of treatment for malignant glioma, radiotherapy and chemotherapy, are unsatisfactory, the development of novel therapeutic compounds is required. In the present study, the inhibitory effect of tetrandrine citrate (TetC) on the proliferation of human glioma U87 cells, as well as its mechanism of action, were investigated. An MTT assay was used to assess cell viability in vitro, and the production of intracellular reactive oxygen species (ROS) was determined by assessing the fluorescence intensity of 2,7-dichlorofluorescein (DCF). Flow cytometry was used to determine the level of apoptosis and cell cycle status, and the protein expression levels of apoptosis-associated proteins were determined using western blotting. Additionally, the antitumor activity of TetC was assessed in vivo using a nude mouse xenograft model. The results revealed that in vitro, the proliferative rate of U87, U251 and human umbilical vein endothelial cells (HUVECs) was significantly reduced in a dose-dependent manner following treatment with TetC, although TetC had the greatest inhibitory effect on U87 cells. The vacuolization and apoptosis of U87 cells was induced using 10 and 20 µmol/l TetC, respectively. The overall proliferative inhibition was associated with an increase in the levels of ROS and apoptosis. In TetC-treated cells, the expression levels of apoptosis-related proteins, including cleaved (CL) caspase-3, Fas, phosphorylated (p)-p38 and p-JNK, were increased, whereas those of caspase-3 and Bcl-2 were decreased. In vivo, TetC was highly effective at inhibiting the growth of human glioma U87 ×enografts in BALB/c nude mice, with a percentage growth inhibition of ≥68.7%. These findings indicated that the potent antitumor activity of TetC may be mediated through an increase in ROS levels, the downregulation of Bcl-2, and the upregulation of CL caspase-3, Fas, p-p38 and p-JNK expression levels.

Hexokinase II Upregulation Contributes to Asiaticoside-Induced Protection of H9c2 Cardioblasts During Oxygen-Glucose Deprivation/Reoxygenation

Asiaticoside (AS), one of the main functional components of Centella asiatica, has been reported to protect neurons from ischemia-hypoxia-induced injury. However, the role of AS in myocardial oxygen-glucose deprivation/reoxygenation (OGD/R) injury has not been investigated. The aim of this study was to investigate the role of AS in OGD/R-treated H9c2 cardiomyocytes and the underlying mechanism involved. Cell viability was detected using MTT assay. Cell apoptosis was measured using flow cytometry. The oxidative stress was assessed by detecting the malonaldehyde (MDA) content and activities of superoxide dismutase, glutathione peroxidase, and catalase (CAT). The glucose consumption and lactate production were determined to reflect glycolysis rate. The expression levels of hexokinase II (HK2) were detected using reverse transcription quantitative polymerase chain reaction and Western blot. H9c2 cells were transfected with small interfering RNA targeting HK2 (si-HK2) to knockdown HK2. Results showed that AS improved cell viability and inhibited apoptosis in OGD/R-injured H9c2 cells. AS pretreatment prevented OGD/R-induced oxidative stress, as evidenced by the decreased MDA content, and increased activities of superoxide dismutase, glutathione peroxidase, and CAT. The decreased glucose consumption and lactate production in OGD/R-injured H9c2 cells were reversed after AS treatment. Mechanically, AS induced the expression of HK2 in OGD/R-injured H9c2 cells. Knockdown of HK2 abolished the protective effects of AS on OGD/R-injured H9c2 cells. In conclusion, the protective effects of AS on cardiomyocytes from OGD/R-induced injury were mediated at least partly by upregulating HK2.

PRR34-AS1 overexpression promotes protection of propofol pretreatment against ischemia/reperfusion injury in a mouse model after total knee arthroplasty via blockade of the JAK1-dependent JAK-STAT signaling pathway

Long noncoding RNAs have been documented to be protective against ischemia/reperfusion (I/R) injury. However, few research works have focused on the protective effects of PRR34-AS1 on I/R injury after total knee arthroplasty (TKA). The objective of the present study was to investigate the possible effect of PRR34-AS1 on I/R injury after TKA. A mouse model with I/R injury after TKA was established. The interaction between PRR34-AS1 and Janus kinase 1 (JAK1) was examined and thoroughly investigated. Next, the effects of PRR34-AS1 on the expression of apoptosis-related proteins, JAS-signal transducer and activator of transcription (STAT) signaling pathways, and inflammation-related genes, chondrocyte proliferation, and apoptosis were analyzed after gain- and loss-of-function experiments. Attenuated symptoms were observed in mice pretreated with propofol, which was evidenced by decreased positive expression rate of JAK1 protein and superoxide dismutase content along with increased malondialdehyde content and IL-10 levels. PRR34-AS1 was poorly expressed in mice with I/R injury after TKA. JAK1 was a target of PRR34-AS1. Upregulated PRR34-AS1 diminished expression of JAK1, STAT1, JAK2, and STAT3 as well as cell apoptosis, while enhancing cell proliferation in vitro. Furthermore, JAK1 silencing could reverse the suppressed cell proliferation and enhanced cell apoptosis of chondrocytes imposed by silencing PRR34-AS1. Upregulation of PRR34-AS1 can potentially relieve I/R injury after TKA in mice pretreated with propofol through inhibition of the JAS-STAT signaling pathway by targeting JAK1.

Proteomics Research on the Protective Effect of Mangiferin on H9C2 Cell Injury Induced by H2O2

Cardiovascular disease is one of the leading causes of morbidity and mortality worldwide. Mangiferin is a natural glucosylxanthone with antioxidant and anti-inflammatory properties, which has been confirmed to protect cardiac cells from myocardial infarction and myocardial ischemia reperfusion injury (MIRI); however, the underlying mechanism is still unclear. As oxidative stress is a major pathogenesis of MIRI, an H9C2 cell injury induced by hydrogen peroxide (H₂O₂) was established to simulate MIRI in vitro. Herein, the protective effect of mangiferin against MIRI was evaluated and the isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomics was applied to explore the underlying molecular mechanism. In this research, mangiferin markedly ameliorated the oxidative imbalance by increasing the antioxidative capacity of the H9C2 cell. Moreover, proteomics analysis revealed that mangiferin pretreatment brought twenty differently-expressed proteins back to normal, most of which were related to glucose and fatty acid metabolism. Glycolysis, citrate cycle, and fatty acid degradation pathways were highlighted by Kyoto Encyclopedia of Gene and Genomes (KEGG) analysis. Western blot validation of six cardiac metabolism-related proteins were consistent with the proteomics analysis. Taken together, mangiferin protected the cardiomyocytes from MIRI by enhancing the antioxidant capacity and increasing the activities of glycolysis, citrate cycle, and fatty acid degradation pathways.

Cardioprotective signalling: Past, present and future

A few decades ago, cardiac muscle was discovered to possess signalling pathways that, when activated, protect the myocardium against the damage induced by ischaemia-reperfusion. The ability of cardiac muscle to protect itself against injury has been termed 'cardioprotection'. Many compounds and procedures can trigger cardioprotection including conditionings (exposure to brief episodes of ischaemia-reperfusion to protect against sustained ischaemia-reperfusion), hypoxia, adenosine, acetylcholine, adrenomedullin, angiotensin, bradykinin, catecholamines, endothelin, estrogens, phenylephrine, opioids, testosterone, and many more. These triggers activate many intracellular signalling factors including protein kinases, different enzymes, transcription factors and defined signalling pathways to target structures in mitochondria, sarcoplasmic reticulum, nucleus and sarcolemma to mediate cardioprotection. Although a lot of information about cardioprotection has been acquired, there are still two major outstanding issues to be addressed in the future 1) better understanding of spatio-temporal relationships between signalling elements, and; 2) devising therapeutic strategies against myocardial diseases based on cardioprotective signalling. Further research is required to paint integral picture of cardioprotective signalling and more clinical studies are required to properly test clinical efficacy and safety of potential cardioprotective strategies. Therapies against cardiac diseases based on cardioprotective strategies would be a perfect adjunct to current therapeutic strategies based on restitution of coronary blood flow and regulation of myocardial metabolic demands.