Peroxiredoxin-1 Overexpression Attenuates Doxorubicin-Induced Cardiotoxicity by Inhibiting Oxidative Stress and Cardiomyocyte Apoptosis

PRDX1 exerts a photoprotection effect by inhibiting oxidative stress and regulating MAPK signaling on retinal pigment epithelium

BACKGROUND

The purpose of this study was to investigate the photoprotection effect of peroxiredoxin 1 (PRDX1) protein in ultraviolet B (UVB) irradiation-induced damage of retinal pigment epithelium (RPE) and its possible molecular mechanism.

METHODS

ARPE-19 cell viability and apoptosis were assessed by MTT assay and flow cytometry, respectively. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the PRDX1 expression. The corresponding kits were employed to measure the levels or activities of lactate dehydrogenase (LDH), 8-hydroxy-2-deoxyguanosine (8-OHdG), reactive oxygen species (ROS), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD). Western blotting was applied to examine PRDX1 expression and mitogen-activated protein kinase (MAPK) signaling pathway-related proteins.

RESULTS

After exposure to 20 mJ/cm2 intensity of UVB irradiation for 24 h, ARPE-19 cells viability was decreased, the leakage degree of LDH and 8-OHdG were increased, and cell apoptosis was elevated. The expression of PRDX1 was significantly down-regulated in UVB-induced ARPE-19 cells. The low expression of PRDX1 was involved in high irradiation intensity. Overexpression of PRDX1 increased cell activity, decreased cell apoptosis, and LDH as well as 8-OHdG leakage in UVB-induced ARPE-19 cells. In addition to alleviating UVB-induced cell damage, PRDX1 overexpression also inhibited UVB-induced oxidative stress (down-regulation of ROS and MDA levels, up-regulation of GSH-Px and SOD activities) and the activation of MAPK signaling pathway in ARPE-19 cells.

CONCLUSION

PRDX1 exerts a photoprotection effect on RPE by attenuating UVB-induced cell damage and inhibiting oxidative stress, which can be attributed to the inhibition of MAPK signaling pathway activation.

Proteomic profiling of renal tissue of normo- and hypertensive rats with the renalase peptide RP220 as an affinity ligand

Renalase (RNLS) is a recently discovered protein that plays an important role in the regulation of blood pressure by acting inside and outside cells. Intracellular RNLS is a FAD-dependent oxidoreductase that oxidizes isomeric forms of β-NAD(P)H. Extracellular renalase lacking its N-terminal peptide and cofactor FAD exerts various protective effects via non-catalytic mechanisms. Certain experimental evidence exists in the literature that the RP220 peptide (a 20-mer peptide corresponding to the amino acid sequence RNLS 220-239) reproduces a number of non-catalytic effects of this protein, acting on receptor proteins of the plasma membrane. The possibility of interaction of this peptide with intracellular proteins has not been studied. Taking into consideration the known role of RNLS as a possible antihypertensive factor, the aim of this study was to perform proteomic profiling of the kidneys of normotensive and hypertensive rats using RP220 as an affinity ligand. Proteomic (semi-quantitative) identification revealed changes in the relative content of about 200 individual proteins in the kidneys of hypertensive rats bound to the affinity sorbent as compared to the kidneys of normotensive animals. Increased binding of SHR renal proteins to RP220 over the normotensive control was found for proteins involved in the development of cardiovascular pathology. Decreased binding of the kidney proteins from hypertensive animals to RP220 was noted for components of the ubiquitin-proteasome system, ribosomes, and cytoskeleton.

Selenoprotein P, peroxiredoxin-5, renalase, and total antioxidant status in patients with suspected obstructive sleep apnea

PURPOSE

The aim of this study was to investigate the relationship between selenoprotein P, peroxiredoxin-5, renalase, total antioxidant status (TAS), mean blood pressure (mBP), and apnea-hypopnea index (AHI).

METHODS

The study group consisted of 112 patients hospitalized to verify the diagnosis of obstructive sleep apnea (OSA). The inclusion criteria were consent to participate in the study and age ≥ 18 years. Patients with active proliferative disease, severe systemic diseases, or mental diseases were excluded from the study. Each patient underwent full polysomnography and had blood pressure measured. Blood samples were collected and laboratory test was performed.

RESULTS

Among 112 patients enrolled, there was a statistically significant negative linear correlation between blood pressure values (sBP, dBP, mBP) and selenoprotein P, renalase, and TAS levels. Similarly, there was a negative linear correlation between AHI and selenoprotein P, renalase, and TAS levels, but none between AHI and peroxiredoxin-5. Based on the obtained regression models, higher selenoprotein P, peroxiredoxin-5, and renalase levels were independently associated with higher TAS. Lower mBP values were independently associated with the use of antihypertensive drugs, higher TAS, and younger age. Male gender, higher BMI, and higher mBP were independently associated with higher AHI.

CONCLUSIONS

Higher concentrations of selenoprotein P, peroxiredoxin-5, and renalase were associated with higher TAS, which confirms their antioxidant properties. There was an indirect connection between tested antioxidants and blood pressure values.

Dual role of PRDX1 in redox-regulation and tumorigenesis: Past and future

Tumour cells often display an active metabolic profile, leading to the intracellular accumulation of reactive oxygen species. As a member of the peroxidase family, peroxiredoxin 1 (PRDX1) functions generally in protecting against cell damage caused by H2O2. Additionally, PRDX1 plays a role as a molecular chaperone in various malignant tumours, exhibiting either tumour-promoting or tumour-suppressing effects. Currently, PRDX1-targeting drugs have demonstrated in vitro anticancer effects, indicating the potential of PRDX1 as a molecular target. Here we discussed the diverse functions of PRDX1 in tumour biology and provided a comprehensive analysis of the therapeutic potential of targeting PRDX1 signalling across various types of cancer.

Tamoxifen induced cardiac damage via the IL-6/p-STAT3/PGC-1α pathway

Tamoxifen (TAM) is an effective anticancer drug for breast and ovarian cancer. However, increased risk of cardiotoxicity is a long-term clinical problem associated with TAM, while the underlying mechanisms remain unclear. Here, we performed experiments in cardiomyocytes and tumor-bearing or nontumor-bearing mice, and demonstrated that TAM induced cardiac injury via the IL-6/p-STAT3/PGC-1α/IL-6 feedback loop, which is responsible for reactive oxygen species (ROS) accumulation. Compared with non-tumor bearing mice, tumor-bearing mice showed stronger cardiac toxicity after TAM injection, although there was no significant difference. In vitro experiments demonstrated STAT3 phosphorylation inhibitor can increase PGC-1α expression and protect cardiomyocyte via decreasing ROS. Since tumor has higher STAT3 phosphorylation and IL-6 expression level, our research results indicated combining TAM and STAT3 inhibitor might be an effective treatment strategy which can provide both tumor killing and cardioprotective function. Further in vivo research is needed to fully elucidate the effect and mechanisms of the combination therapy of TAM and STAT3 inhibitor.

Effect of peroxiredoxin 1 on the regulation of trophoblast function by affecting autophagy and oxidative stress in preeclampsia

PURPOSE

PE is a pregnancy-specific syndrome and one of the main causes of maternal, fetal, and neonatal mortality. PRDX1 is an antioxidant that regulates cell proliferation, differentiation, and apoptosis. The aim of this study is to investigate the effect of PRDX1 on the regulation of trophoblast function by affecting autophagy and oxidative stress in preeclampsia.

METHODS

Western blotting, RT-qPCR, and immunofluorescence were used to examine the expression of PRDX1 in placentas. PRDX1-siRNA was transfected to knockdown PRDX1 in HTR-8/SVneo cells. The biological function of HTR-8/SVneo cells was detected by wound healing, invasion, tube formation, CCK-8, EdU, flow cytometry, and TUNEL assays. Western blotting was used to detect the protein expression of cleaved-Caspase3, Bax, LC3II, Beclin1, PTEN, and p-AKT. DCFH-DA staining was used to detect ROS levels by flow cytometry.

RESULTS

PRDX1 was significantly decreased in placental trophoblasts in PE patients. Following the exposure of HTR-8/SVneo cells to H₂O₂, PRDX1 expression was significantly decreased, LC3II and Beclin1 expression was notably increased, and ROS level was also markedly increased. PRDX1 knockdown impaired migration, invasion, and tube-formation abilities and promoted apoptosis, which was accompanied by an increased expression of cleaved-Caspase3 and Bax. PRDX1 knockdown induced a significant decrease in LC3II and Beclin1 expression, along with an elevated p-AKT expression and a decreased PTEN expression. PRDX1 knockdown increased intracellular ROS levels, and NAC attenuated PRDX1 knockdown-induced apoptosis.

CONCLUSION

PRDX1 regulated trophoblast function through the PTEN/AKT signaling pathway to affect cell autophagy and ROS level, which provided a potential target for the treatment of PE.

Hyperoside alleviates doxorubicin-induced myocardial cells apoptosis by inhibiting the apoptosis signal-regulating kinase 1/p38 pathway

Background

Cardiotoxicity is a side effect of the anthracycline broad-spectrum anti-tumor agent, doxorubicin (DOX). Hyperoside, a flavonoid glycoside extracted from many herbs, has anti-apoptotic and anticancer properties. However, its impact on the alleviation of DOX-induced apoptosis in cardiomyocytes remains elusive.

Methods

The HL-1 cell line was treated with 100 µ M hyperoside for 1 h prior to treatment with 100 µ M hyperoside and 1 µ M DOX for 24 h. The cell counting kit-8 (CCK-8) assay was used to detect cell viability; DCFH-DA fluorescent probe was used to detect (reactive oxygen species) ROS; biochemical methods were used to detect the activity of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA); the degree of apoptosis following DOX insult was assessed using immunofluorescence staining and terminal deoxynucleotidyl transferase mediated deoxy uridine triphosphate nick end labeling (TUNEL) assay; the change in protein expression of apoptosis signal-regulating kinase 1 (ASK1), p38, and apoptosis markers was determined using western blot.

Results

Hyperoside ameliorated DOX-induced oxidative stress in HL-1 cells, up-regulated GSH, SOD and CAT activity, reduced ROS production and inhibited MDA overproduction. Moreover, in addition to promoting HL-1 cell apoptosis, DOX administration also increased B-cell lymphoma (Bcl)-2-associated X-protein and cleaved caspase-3 protein levels and decreased Bcl-2 protein level. Hyperoside therapy, however, significantly reversed the impact of DOX on the cardiomyocytes. Mechanically, DOX treatment increased the phosphorylation of the ASK1/p38 axis whereas hyperoside treatment attenuated those changes. In a further step, hyperoside synergizes with DOX to kill MDA-MB-231 cells.

Conclusions

Hyperoside protects HL-1 cells from DOX-induced cardiotoxicity by inhibiting the ASK1/p38 signaling pathway. Meanwhile, hyperoside maintained the cytotoxicity of DOX in MDA-MB-231 cells.

EEF1A2 accelerates the protein translation of chemokine in rat myocardial cells induced by ischemia-reperfusion

How to reduce the damage caused by myocardial ischemia-reperfusion (IR) in a timely manner to save patients' lives is still a great clinical challenge. Although dexmedetomidine (DEX) has been reported to protect the myocardium, the regulatory mechanism of gene translation responding to IR injury and DEX protection is poorly understood. In this study, IR rat model with DEX and the antagonist yohimbine (YOH) pretreatment were established, and RNA sequencing was carried out to seek the important regulators in differential expressed genes. A series of cytokines and chemokine as well as eukaryotic translation elongation factor 1 alpha 2 (EEF1A2) were induced by IR compared to control and compromised by DEX pretreatment compared to IR, then reversed by YOH. Immunoprecipitation was conducted to identify that peroxiredoxin 1 (PRDX1) interacted with EEF1A2 and contributed to the recruitment of EEF1A2 on mRNA molecules of cytokines and chemokine. Knockdown of PRDX1 could weaken the enhancive effect of EEF1A2 for gene translation of IL6, CXCL2 and CXCL11 under the IR condition, and indeed reduce cell apoptosis of cardiomyocytes. We also determined that the RNA motif "USCAGDCU" at 5' UTR could be particularly recognized by PRDX1. Destruction of this motif at the 5' UTR of IL6, CXCL2 and CXCL11 by CRISPR-CAS9 could result in the loss occupancies of EEF1A2 and PRDX1 on the mRNA of these three genes. Our observations showed the importance of PRDX1 in the reasonable control of cytokine and chemokine expression to prevent excessive inflammatory response to cell damage.

Differential plasma protein expression after ingestion of essential amino acid-based dietary supplement verses whey protein in low physical functioning older adults

In a recent randomized, double-blind, placebo-controlled trial, we were able to demonstrate the superiority of a dietary supplement composed of essential amino acids (EAAs) over whey protein, in older adults with low physical function. In this paper, we describe the comparative plasma protein expression in the same subject groups of EAAs vs whey. The plasma proteomics data was generated using SOMA scan assay. A total of twenty proteins were found to be differentially expressed in both groups with a 1.5-fold change. Notably, five proteins showed a significantly higher fold change expression in the EAA group which included adenylate kinase isoenzyme 1, casein kinase II 2-alpha, Nascent polypeptide-associated complex subunit alpha, peroxiredoxin-1, and peroxiredoxin-6. These five proteins might have played a significant role in providing energy for the improved cardiac and muscle strength of older adults with LPF. On the other hand, fifteen proteins showed slightly lower fold change expression in the EAA group. Some of these 15 proteins regulate metabolism and were found to be associated with inflammation or other comorbidities. Gene Ontology (GO) enrichment analysis showed the association of these proteins with several biological processes. Furthermore, protein-protein interaction network analysis also showed distinct networks between upregulated and downregulated proteins. In conclusion, the important biological roles of the upregulated proteins plus better physical function of participants in the EAAs vs whey group demonstrated that EAAs have the potential to improve muscle strength and physical function in older adults. This study was registered with ClinicalTrials.gov: NCT03424265 "Nutritional interventions in heart failure."

Untargeted Metabolomics Studies of H9c2 Cardiac Cells Submitted to Oxidative Stress, β-Adrenergic Stimulation and Doxorubicin Treatment: Investigation of Cardiac Biomarkers

One of the biggest challenges in the search for more effective treatments for diseases is understanding their etiology. Cardiovascular diseases (CVD) are an important example of this, given the high number of deaths annually. Oxidative stress (the imbalance between oxidant and antioxidant species in biological system) is one of the factors responsible for CVD occurrence, demanding extensive investigation. Excess of reactive oxygen species (ROS) are primarily responsible for this condition, and clinical and scientific literature have reported a significant increase in ROS when therapeutic drugs, such as doxorubicin and isoproterenol, are administered. In this context, the aim of this study is the investigation of potential biomarkers that might be associated with oxidative stress in cardiomyocytes. For this purpose, H9c2 cardiomyocytes were submitted to oxidative stress conditions by treatment with doxorubicin (DOX), isoproterenol (ISO) and hydrogen peroxide (PER). Metabolomics analyses of the cell extract and the supernatant obtained from the culture medium were then evaluated by CE-ESI(+)-TOF-MS. Following signal processing, statistical analyses, and molecular features annotations, the results indicate changes in the aspartate, serine, pantothenic acid, glycerophosphocholine and glutathione metabolism in the cell extract.

Protective effect of Di'ao Xinxuekang capsule against doxorubicin-induced chronic cardiotoxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Di'ao Xinxuekang capsule (DXXK) extracted from Dioscorea nipponica Makino is a well-known traditional Chinese herbal medicinal product widely used in the treatment of cardiovascular disease, such as myocardial ischemia and arrhythmia. The active ingredients of DXXK were also traditionally utilized for treating cardiovascular disease in the former Soviet Union after the 1960s. As a specific type of cardiovascular disease, doxorubicin (DOX)-induced cardiotoxicity is characterized by arrhythmia, myocardial ischemia, and heart failure.

AIM OF THE STUDY

This study aimed to investigate the potential protective effect of DXXK against chronic cardiotoxicity induced by DOX.

MATERIALS AND METHODS

A mouse model of chronic cardiotoxicity induced by DOX and an in vitro model of DOX-induced myocardial damage were created to assess the protective effect of DXXK. Cardiac functional parameters, serum levels of CK-MB and LDH and cardiac histopathological indicators were determined in the mouse model. Moreover, cell viability was measured by the MTT method, and the effect of DXXK on the anticancer activity of DOX was also investigated by utilizing 4T1, HepG2, and H460 cell lines. Furthermore, the levels of markers of oxidative stress indexes (SOD, GSH, MDA) and inflammation (TNF-α, IL-1α) were measured using biochemical and Elisa kits, respectively. The level of ROS in H9c2 cardiomyocyte was determined by flow cytometry. The protein expression levels of HIF-1α and NF-κB p65 were measured by western blotting. Finally, molecular docking was performed to visualize the patterns of interactions between the effective molecule and targeted protein.

RESULTS

DXXK alleviated DOX-induced chronic cardiotoxicity as shown by the reversal of changes in levels of myocardial enzymes and left ventricular function and structure. DXXK exhibits antioxidant and anti-inflammatory activities. We also observed that DXXK might increase the protein expression level of HIF-1α and decrease the protein expression level of NF-κB p65. Further results of in vitro experiments showed that DXXK could protect cardiomyocyte against DOX-induced production of ROS, but DXXK had no effect on the anticancer activity of DOX. The results of molecular docking showed that dioscin and pseudoprotodioscin were the top two compounds of DXXK, which had high affinity with HIF-1α and NF-κB p65.

CONCLUSIONS

Our results indicated that DXXK could protect against cardiotoxicity induced by DOX and alleviate oxidative stress and inflammation in vivo and in vitro via the regulation of HIF-1α and down NF-κB p65.

RRM2 Alleviates Doxorubicin-Induced Cardiotoxicity through the AKT/mTOR Signaling Pathway

Doxorubicin (DOX) is an effective chemotherapeutic agent that plays an unparalleled role in cancer treatment. However, its serious dose-dependent cardiotoxicity, which eventually contributes to irreversible heart failure, has greatly limited the widespread clinical application of DOX. A previous study has demonstrated that the ribonucleotide reductase M2 subunit (RRM2) exerts salutary effects on promoting proliferation and inhibiting apoptosis and autophagy. However, the specific function of RRM2 in DOX-induced cardiotoxicity is yet to be determined. This study aimed to elucidate the role and potential mechanism of RRM2 on DOX-induced cardiotoxicity by investigating neonatal primary cardiomyocytes and mice treated with DOX. Subsequently, the results indicated that RRM2 expression was significantly reduced in mice hearts and primary cardiomyocytes. Apoptosis and autophagy-related proteins, such as cleaved-Caspase3 (C-Caspase3), LC3B, and beclin1, were distinctly upregulated. Additionally, RRM2 deficiency led to increased autophagy and apoptosis in cells. RRM2 overexpression, on the contrary, alleviated DOX-induced cardiotoxicity in vivo and in vitro. Consistently, DIDOX, an inhibitor of RRM2, attenuated the protective effect of RRM2. Mechanistically, we found that AKT/mTOR inhibitors could reverse the function of RRM2 overexpression on DOX-induced autophagy and apoptosis, which means that RRM2 could have regulated DOX-induced cardiotoxicity through the AKT/mTOR signaling pathway. In conclusion, our experiment established that RRM2 could be a potential treatment in reversing DOX-induced cardiac dysfunction.

Peroxiredoxin-5 Knockdown Accelerates Pressure Overload-Induced Cardiac Hypertrophy in Mice

A recent study showed that peroxiredoxins (Prxs) play an important role in the development of pathological cardiac hypertrophy. However, the involvement of Prx5 in cardiac hypertrophy remains unclear. Therefore, this study is aimed at investigating the role and mechanisms of Prx5 in pathological cardiac hypertrophy and dysfunction. Transverse aortic constriction (TAC) surgery was performed to establish a pressure overload-induced cardiac hypertrophy model. In this study, we found that Prx5 expression was upregulated in hypertrophic hearts and cardiomyocytes. In addition, Prx5 knockdown accelerated pressure overload-induced cardiac hypertrophy and dysfunction in mice by activating oxidative stress and cardiomyocyte apoptosis. Importantly, heart deterioration caused by Prx5 knockdown was related to mitogen-activated protein kinase (MAPK) pathway activation. These findings suggest that Prx5 could be a novel target for treating cardiac hypertrophy and heart failure.

Peroxiredoxins as Potential Targets for Cardiovascular Disease

Increased oxidative stress (OS) is considered a common etiology in the pathogenesis of cardiovascular disease (CVD). Therefore, the precise regulation of reactive oxygen species (ROS) in cardiovascular cells is essential to maintain normal physiological functions. Numerous regulators of cellular homeostasis are reportedly influenced by ROS. Hydrogen peroxide (H₂O₂), as an endogenous ROS in aerobic cells, is a toxic substance that can induce OS. However, many studies conducted over the past two decades have provided substantial evidence that H₂O₂ acts as a diffusible intracellular signaling messenger. Antioxidant enzymes, including superoxide dismutases, catalase, glutathione peroxidases, and peroxiredoxins (Prdxs), maintain the balance of ROS levels against augmentation of ROS production during the pathogenesis of CVD. Especially, Prdxs are regulatory sensors of transduced intracellular signals. The intracellular abundance of Prdxs that specifically react with H₂O₂ act as regulatory proteins. In this review, we focus on the role of Prdxs in the regulation of ROS-induced pathological changes in the development of CVD.

Cullin-5 neddylation-mediated NOXA degradation is enhanced by PRDX1 oligomers in colorectal cancer

NOXA, a BH3-only proapoptotic protein involved in regulating cell death decisions, is highly expressed but short-lived in colorectal cancer (CRC). Neddylated cullin-5 (CUL5)-mediated ubiquitination and degradation of NOXA is crucial to prevent its overaccumulation and maintain an appropriate action time. However, how this process is manipulated by CRC cells commonly exposed to oxidative stress remain unknown. The peroxiredoxin PRDX1, a conceivable antioxidant overexpressed in CRC tissues, has been shown to inhibit apoptosis and TRAF6 ubiquitin-ligase activity. In this study, we found that PRDX1 inhibits CRC cell apoptosis by downregulating NOXA. Mechanistically, PRDX1 promotes NOXA ubiquitination and degradation, which completely depend on CUL5 neddylation. Further studies have demonstrated that PRDX1 oligomers bind with both the Nedd8-conjugating enzyme UBE2F and CUL5 and that this tricomplex is critical for CUL5 neddylation, since silencing PRDX1 or inhibiting PRDX1 oligomerization greatly dampens CUL5 neddylation and NOXA degradation. An increase in reactive oxygen species (ROS) is not only a hallmark of cancer cells but also the leading driving force for PRDX1 oligomerization. As shown in our study, although ROS play a role in upregulating NOXA mRNA transcription, ROS scavenging in CRC cells by N-acetyl-L-cysteine (NAC) can significantly reduce CUL5 neddylation and extend the NOXA protein half-life. Therefore, in CRC, PRDX1 plays a key role in maintaining intracellular homeostasis under conditions of high metabolic activity by reinforcing UBE2F-CUL5-mediated degradation of NOXA, which is also evidenced in the resistance of CRC cells to etoposide treatment. Based on these findings, targeting PRDX1 could be an effective strategy to overcome the resistance of CRC to DNA damage-inducing chemotherapeutics.

Interleukin-22 Plays a Protective Role by Regulating the JAK2-STAT3 Pathway to Improve Inflammation, Oxidative Stress, and Neuronal Apoptosis following Cerebral Ischemia-Reperfusion Injury

The interleukins (ILs) are a pluripotent cytokine family that have been reported to regulate ischemic stroke and cerebral ischemia/reperfusion (I/R) injury. IL-22 is a member of the IL-10 superfamily and plays important roles in tissue injury and repair. However, the effects of IL-22 on ischemic stroke and cerebral I/R injury remain unclear. In the current study, we provided direct evidence that IL-22 treatment decreased infarct size, neurological deficits, and brain water content in mice subjected to cerebral I/R injury. IL-22 treatment remarkably reduced the expression of inflammatory cytokines, including IL-1β, monocyte chemotactic protein- (MCP-) 1, and tumor necrosis factor- (TNF-) α, both in serum and the ischemic cerebral cortex. In addition, IL-22 treatment also decreased oxidative stress and neuronal apoptosis in mice after cerebral I/R injury. Moreover, IL-22 treatment significantly increased Janus tyrosine kinase (JAK) 2 and signal transducer and activator of transcription (STAT) 3 phosphorylation levels in mice and PC12 cells, and STAT3 knockdown abolished the IL-22-mediated neuroprotective function. These findings suggest that IL-22 might be exploited as a potential therapeutic agent for ischemic stroke and cerebral I/R injury.

Palmatine Protects against Cerebral Ischemia/Reperfusion Injury by Activation of the AMPK/Nrf2 Pathway

Palmatine (PAL), a natural isoquinoline alkaloid, possesses extensive biological and pharmaceutical activities, including antioxidative stress, anti-inflammatory, antitumor, neuroprotective, and gastroprotective activities. However, it is unknown whether PAL has a protective effect against ischemic stroke and cerebral ischemia/reperfusion (I/R) injury. In the present study, a transient middle cerebral artery occlusion (MCAO) mouse model was used to mimic ischemic stroke and cerebral I/R injury in mice. Our study demonstrated that PAL treatment ameliorated cerebral I/R injury by decreasing infarct volume, neurological scores, and brain water content. PAL administration attenuated oxidative stress, the inflammatory response, and neuronal apoptosis in mice after cerebral I/R injury. In addition, PAL treatment also decreases hypoxia and reperfusion- (H/R-) induced neuronal injury by reducing oxidative stress, the inflammatory response, and neuronal apoptosis. Moreover, the neuroprotective effects of PAL were associated with the activation of the AMP-activated protein kinase (AMPK)/nuclear factor E2-related factor 2 (Nrf2) pathway, and Nrf2 knockdown offsets PAL-mediated antioxidative stress and anti-inflammatory effects. Therefore, our results suggest that PAL may be a novel treatment strategy for ischemic stroke and cerebral I/R injury.

1-O-Hexyl-2,3,5-Trimethylhydroquinone Ameliorates the Development of Preeclampsia through Suppression of Oxidative Stress and Endothelial Cell Apoptosis

1-O-Hexyl-2,3,5-trimethylhydroquinone (HTHQ), a potent nuclear factor-E2-related factor 2 (Nrf2) activator, has potent antioxidant activity by scavenging reactive oxygen species (ROS). However, the role of HTHQ on the development of preeclampsia (PE) and the underlying mechanisms have barely been explored. In the present study, PE model was induced by adenovirus-mediated overexpression of soluble fms-like tyrosine kinase 1 (sFlt-1) in pregnant mice. The results showed that HTHQ treatment significantly relieved the high systolic blood pressure (SBP) and proteinuria and increased the fetal weight and fetal weight/placenta weight in preeclamptic mice. Furthermore, we found that HTHQ treatment significantly decreased soluble endoglin (sEng), endothelin-1 (ET-1), and activin A and restored vascular endothelial growth factor (VEGF) in preeclamptic mice. In addition, HTHQ treatment inhibited oxidative stress and endothelial cell apoptosis by increasing the levels of Nrf2 and its downstream haemoxygenase-1 (HO-1) protein. In line with the data in vivo, we discovered that HTHQ treatment attenuated oxidative stress and cell apoptosis in human umbilical vein endothelial cells (HUVECs) following hypoxia and reperfusion (H/R), and the HTHQ-mediated protection was lost after transfected with siNrf2. In conclusion, these results suggested that HTHQ ameliorates the development of preeclampsia through suppression of oxidative stress and endothelial cell apoptosis.