Exploring the role of Prx II in mitigating endoplasmic reticulum stress and mitochondrial dysfunction in neurodegeneration

BACKGROUND

Neurodegenerative diseases are increasingly recognized for their association with oxidative stress, which leads to progressive dysfunction and loss of neurons, manifesting in cognitive and motor impairments. This study aimed to elucidate the neuroprotective role of peroxiredoxin II (Prx II) in counteracting oxidative stress-induced mitochondrial damage, a key pathological feature of neurodegeneration.

METHODS

We investigated the impact of Prx II deficiency on endoplasmic reticulum stress and mitochondrial dysfunction using HT22 cell models with knocked down and overexpressed Prx II. We observed alcohol-treated HT22 cells using transmission electron microscopy and monitored changes in the length of mitochondria-associated endoplasmic reticulum membranes and their contact with endoplasmic reticulum mitochondria contact sites (EMCSs). Additionally, RNA sequencing and bioinformatic analysis were conducted to identify the role of Prx II in regulating mitochondrial transport and the formation of EMCSs.

RESULTS

Our results indicated that Prx II preserves mitochondrial integrity by facilitating the formation of EMCSs, which are essential for maintaining mitochondrial Ca2+ homeostasis and preventing mitochondria-dependent apoptosis. Further, we identified a novel regulatory axis involving Prx II, the transcription factor ATF3, and miR-181b-5p, which collectively modulate the expression of Armcx3, a protein implicated in mitochondrial transport. Our findings underscore the significance of Prx II in protecting neuronal cells from alcohol-induced oxidative damage and suggest that modulating the Prx II-ATF3-miR-181b-5p pathway may offer a promising therapeutic strategy against neurodegenerative diseases.

CONCLUSIONS

This study not only expands our understanding of the cytoprotective mechanisms of Prx II but also offers necessary data for developing targeted interventions to bolster mitochondrial resilience in neurodegenerative conditions.

Argon non-thermal plasma treatment promotes the development of rice (Oryza sativa L.) in saline alkali environments

Soil salinization leads to a reduction in arable land area, which seriously endangers food security. Developing saline-alkali land has become a key measure to address the contradiction between population growth and limited arable land. Rice is the most important global food crop, feeding half of the world's population and making it a suitable choice for planting on saline-alkali lands. The traditional salt-alkali improvement method has several drawbacks. Currently, non-thermal plasma (NTP) technology is being increasingly applied in agriculture. However, there are few reports on the cultivation of salt/alkali-tolerant rice. Under alkaline stress, argon NTP treatment significantly increased the germination rate of Longdao 5 (LD5) rice seeds. In addition, at 15 kV and 120 s, NTP treatment significantly increased the activity of antioxidant enzymes such as catalase and SOD. NTP treatment induced changes in genes related to salt-alkali stress in rice seedlings, such as chitinase and xylanase inhibitor proteins, which increased the tolerance of the seeds to salt-alkali stress. This experiment has expanded the application scope of NTP in agriculture, providing a more cost-effective, less harmful, and faster method for developing salt-alkali-tolerant rice and laying a theoretical foundation for cultivating NTP-enhanced salt-alkali-tolerant rice.

Cisplatin Induces Kidney Cell Death via ROS-dependent MAPK Signaling Pathways by Targeting Peroxiredoxin I and II in African Green Monkey (Chlorocebus aethiops sabaeus) Kidney Cells

BACKGROUND/AIM

Cisplatin [cis-diamminedichloroplatinum(II), CDDP] is a widely used and effective antitumor drug in clinical settings, notorious for its nephrotoxic side effects. This study investigated the mechanisms of CDDP-induced damage in African green monkey kidney (Vero) cells, with a focus on the role of Peroxiredoxin I (Prx I) and Peroxiredoxin II (Prx II) of the peroxiredoxin (Prx) family, which scavenge reactive oxygen species (ROS).

MATERIALS AND METHODS

We utilized the Vero cell line derived from African green monkey kidneys and exposed these cells to various concentrations of CDDP. Cell viability, apoptosis, ROS levels, and mitochondrial membrane potential were assessed.

RESULTS

CDDP significantly compromised Vero cell viability by elevating both cellular and mitochondrial ROS, which led to increased apoptosis. Pretreatment with the ROS scavenger N-acetyl-L-cysteine (NAC) effectively reduced CDDP-induced ROS accumulation and subsequent cell apoptosis. Furthermore, CDDP reduced Prx I and Prx II levels in a dose- and time-dependent manner. The inhibition of Prx I and II exacerbated cell death, implicating their role in CDDP-induced accumulation of cellular ROS. Additionally, CDDP enhanced the phosphorylation of MAPKs (p38, ERK, and JNK) without affecting AKT. The inhibition of these pathways significantly attenuated CDDP-induced apoptosis.

CONCLUSION

The study highlights the involvement of Prx proteins in CDDP-induced nephrotoxicity and emphasizes the central role of ROS in cell death mediation. These insights offer promising avenues for developing clinical interventions to mitigate the nephrotoxic effects of CDDP.

Identification and diagnostic potential of serum microRNAs as biomarkers for early detection of Alzheimer's disease

This study aimed to investigate the differential expression of serum microRNAs in cognitive normal subjects (NC), patients with mild cognitive impairment (MCI), and patients with Alzheimer's disease (AD), with the objective of identifying potential diagnostic biomarkers. A total of 320 clinical samples, including 32 MCI patients, 288 AD patients, and 288 healthy controls, were collected following international standards. The expression of microRNAs in serum was analyzed using the Agilent human microRNA oligonucleotide microarray, and bioinformatics methods were employed to predict target genes and their involvement in AD-related pathways. Among the 122 microRNAs screened, five microRNAs (hsa-miR-208a-5p, hsa-miR-125b-1-3p, hsa-miR-3194-3p, hsa-miR-4652-5p, and hsa-miR-4419a) exhibited differential expression and met quality control standards. Bioinformatics analysis revealed that the target genes of these microRNAs were involved in multiple AD-related pathways, which changed with disease progression. These findings demonstrate significant differences in serum microRNA expression between NC, MCI, and AD patients. Three microRNAs were identified as potential candidates for the development of diagnostic models for MCI and AD. The results highlight the crucial role of microRNAs in the pathogenesis of AD and provide a foundation for the development of novel therapeutic strategies and personalized treatment approaches for AD. This study contributes to the understanding of AD at the molecular level and offers potential avenues for early diagnosis and intervention in AD patients.

Peroxiredoxin II regulates exosome secretion from dermal mesenchymal stem cells through the ISGylation signaling pathway

BACKGROUND

Exosomes are small extracellular vesicles that play important roles in intercellular communication and have potential therapeutic applications in regenerative medicine. Dermal mesenchymal stem cells (DMSCs) are a promising source of exosomes due to their regenerative and immunomodulatory properties. However, the molecular mechanisms regulating exosome secretion from DMSCs are not fully understood.

RESULTS

In this study, the role of peroxiredoxin II (Prx II) in regulating exosome secretion from DMSCs and the underlying molecular mechanisms were investigated. It was discovered that depletion of Prx II led to a significant reduction in exosome secretion from DMSCs and an increase in the number of intracellular multivesicular bodies (MVBs), which serve as precursors of exosomes. Mechanistically, Prx II regulates the ISGylation switch that controls MVB degradation and impairs exosome secretion. Specifically, Prx II depletion decreased JNK activity, reduced the expression of the transcription inhibitor Foxo1, and promoted miR-221 expression. Increased miR-221 expression inhibited the STAT signaling pathway, thus downregulating the expression of ISGylation-related genes involved in MVB degradation. Together, these results identify Prx II as a critical regulator of exosome secretion from DMSCs through the ISGylation signaling pathway.

CONCLUSIONS

Our findings provide important insights into the molecular mechanisms regulating exosome secretion from DMSCs and highlight the critical role of Prx II in controlling the ISGylation switch that regulates DMSC-exosome secretion. This study has significant implications for developing new therapeutic strategies in regenerative medicine. Video Abstract.

RNA-Seq-Based Transcriptome Analysis of Nitric Oxide Scavenging Response in Neurospora crassa

While the biological role of naturally occurring nitric oxide (NO) in filamentous fungi has been uncovered, the underlying molecular regulatory networks remain unclear. In this study, we conducted an analysis of transcriptome profiles to investigate the initial stages of understanding these NO regulatory networks in Neurospora crassa, a well-established model filamentous fungus. Utilizing RNA sequencing, differential gene expression screening, and various functional analyses, our findings revealed that the removal of intracellular NO resulted in the differential transcription of 424 genes. Notably, the majority of these differentially expressed genes were functionally linked to processes associated with carbohydrate and amino acid metabolism. Furthermore, our analysis highlighted the prevalence of four specific protein domains (zinc finger C2H2, PLCYc, PLCXc, and SH3) in the encoded proteins of these differentially expressed genes. Through protein-protein interaction network analysis, we identified eight hub genes with substantial interaction connectivity, with mss-4 and gel-3 emerging as possibly major responsive genes during NO scavenging, particularly influencing vegetative growth. Additionally, our study unveiled that NO scavenging led to the inhibition of gene transcription related to a protein complex associated with ribosome biogenesis. Overall, our investigation suggests that endogenously produced NO in N. crassa likely governs the transcription of genes responsible for protein complexes involved in carbohydrate and amino acid metabolism, as well as ribosomal biogenesis, ultimately impacting the growth and development of hyphae.

Regulation of anoikis by extrinsic death receptor pathways

Metastatic cancer cells can develop anoikis resistance in the absence of substrate attachment and survive to fight tumors. Anoikis is mediated by endogenous mitochondria-dependent and exogenous death receptor pathways, and studies have shown that caspase-8-dependent external pathways appear to be more important than the activity of the intrinsic pathways. This paper reviews the regulation of anoikis by external pathways mediated by death receptors. Different death receptors bind to different ligands to activate downstream caspases. The possible mechanisms of Fas-associated death domain (FADD) recruitment by Fas and TNF receptor 1 associated-death domain (TRADD) recruitment by tumor necrosis factor receptor 1 (TNFR1), and DR4- and DR5-associated FADD to induce downstream caspase activation and regulate anoikis were reviewed. This review highlights the possible mechanism of the death receptor pathway mediation of anoikis and provides new insights and research directions for studying tumor metastasis mechanisms. Video Abstract.

Role of NLRP3 inflammasome-mediated neuronal pyroptosis and neuroinflammation in neurodegenerative diseases

BACKGROUND

Neurodegenerative diseases are a common group of neurological disorders characterized by progressive loss of neuronal structure and function leading to cognitive impairment. Recent studies have shown that neuronal pyroptosis mediated by the NLRP3 inflammasome plays a crucial role in the pathogenesis of neurodegenerative diseases.

OBJECTIVE AND METHOD

The NLRP3 inflammasome is a multiprotein complex that, when activated within cells, triggers an inflammatory response, ultimately leading to pyroptotic cell death of neurons. Pyroptosis is a typical pro-inflammatory programmed cell death process occurring downstream of NLRP3 inflammasome activation, characterized by the formation of pores on the cell membrane by the GSDMD protein, leading to cell lysis and the release of inflammatory factors. It has been found that NLRP3 inflammasome-mediated neuronal pyroptosis is closely associated with the development of various neurodegenerative diseases, such as Alzheimer's disease, traumatic brain injury, and Parkinson's disease. Therefore, inhibiting NLRP3 inflammasome activation and attenuating neuronal pyroptosis could potentially serve as novel strategies for the treatment of neurodegenerative diseases.

RESULTS

The aim of this review is to explore the role of NLRP3 activation-mediated neuronal pyroptosis and neuroinflammation in neurodegenerative diseases. Firstly, we extensively discuss the relationship between NLRP3 inflammasome-mediated neuronal pyroptosis and neuroinflammation in various neurodegenerative diseases. Subsequently, we further explore the mechanisms driving NLRP3 activation and assembly, as well as the post-translational modifications regulating NLRP3 inflammasome activation.

CONCLUSION

Understanding these mechanisms will contribute to a deeper understanding of the link between neuronal pyroptosis and neurodegenerative diseases, and hold significant implications for the treatment and prevention of neurodegenerative diseases.

Depletion of peroxiredoxin II promotes keratinocyte apoptosis and alleviates psoriatic skin lesions via the PI3K/AKT/GSK3β signaling axis

Psoriasis is a chronic, systemic immune-mediated disease caused by abnormal proliferation, decreased apoptosis, and over-differentiation of keratinocytes. The psoriatic skin lesions due to abnormal keratinocytes are closely associated with ROS produced by inflammatory cells. Peroxiredoxin II (Prx II) is an efficient antioxidant enzyme, which were highly expressed in skin tissues of psoriasis patient. However, the detailed mechanical functions of Prx II on psoriatic skin remain to be elucidated. Present study showed that depletion of Prx II results in alleviation of symptoms of IMQ-induced psoriasis in mice, but no significant differences in the amounts of serum inflammatory factors. Prx II-knockdown HaCaT cells were susceptible to H₂O₂-induced apoptosis mediated by Ca²⁺ release from the endoplasmic reticulum through 1,4,5-triphosphate receptors (IP3Rs), the PI3K/AKT pathway and phosphorylated GSK3β (Ser9) were significant downregulated. Additionally, significantly reduced sensitivity of Prx II-knockdown HaCaT cells to apoptosis was evident post NAC, 2-APB, BAPTA-AM, SC79 and LiCl treated. These results suggest that Prx II regulated apoptosis of keratinocytes via the PI3K/AKT/GSK3β signaling axis. Furthermore, treatment with the Prx II inhibitor Conoidin A significantly alleviated psoriatic symptoms in IMQ model mice. These findings have important implications for developing therapeutic strategies through regulate apoptosis of keratinocytes in psoriasis, and Prx II inhibitors may be exploited as a therapeutic drug to alleviate psoriatic symptoms.

Identification of Hub Genes and Upstream Regulatory Factors Based on Cell Adhesion in Triple-negative Breast Cancer by Integrated Bioinformatical Analysis

BACKGROUND/AIM

Triple-negative breast cancer (TNBC) is characterized by metastasis and invasion, as well as poor prognosis, with chemotherapy being the main treatment option. Cell adhesion regulates tumorigenesis and new blood vessel formation. Thus, accurately identifying effective targets for TNBC and cell adhesion is challenging. Herein, we screened for differentially expressed genes between TNBC and normal cancer-free tissues to identify genes contributing to TNBC.

MATERIALS AND METHODS

Microarray data were obtained using a comprehensive gene-expression database. We used Database for Annotation, Visualization and Integrated Discovery, Kyoto Encyclopedia of Genes and Genomes and Functional Enrichment (FunRich) to perform Gene Ontology functional enrichment and predict signal pathways. The protein interaction network was predicted using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Cytoscape v. 3.8.2. for visualization of results. TargetScan, miRanda, miRDB, miRWalk and RNA22 were used to predict miRNAs regulating key genes, and long non-coding RNAs (lncRNAs) regulating miRNAs were predicted using StarBase V2.0 from a comprehensive gene-expression database.

RESULTS

Differentially expressed genes were mainly concentrated in the biological process of cell-cell adhesion. The protein-protein interaction network identified eight hub genes: Fibronectin 1 (FN1), Rac family small GTPase 1 (RAC1), heat-shock protein 90 alpha family class B member 1 (HSP90AB1), tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ), heat-shock protein family A member 8 (HSPA8), IQ motif containing GTPase-activating protein 1 (IQGAP1), CD44 molecule (CD44), and catenin beta 1 (CTNNB1). miRNAs related to TNBC occurrence and development were hsa-miR-142-5p, hsa-miR-144, hsa-miR-28-5p, hsa-miR-548d-3p, hsa-miR-587, hsa-miR-641, and hsa-miR-708. StarBase v2.0 predicted 12 lncRNAs, namely NEAT1, XIST, OIP5-AS1, MALAT1, AL035425.3, NORAD, AL391069.4, AC118758.3, AC026362.1, AC009065.4, AC016876.2, and AC093010.3, as upstream molecules that regulate miRNAs and which may regulate TNBC.

CONCLUSION

Overall, mRNA-miRNA-lncRNA interactions appear to play a role in TNBC development.

Induction of Targeted Differentiation of Dermal Mesenchymal Stem Cells Into Neural Lineage According to Peroxiredoxin II Expression

BACKGROUND/AIM

To optimize the therapeutic potential of stem cells in stem cell therapy for neurological diseases, it is crucial to enhance the differentiation, migration, and neural network formation of stem cells, and to eliminate uncertain cell differentiation and proliferation factors. Several studies have shown that reactive oxygen species (ROS) are important factors in the regulation of neurogenesis, and Prx II (Peroxiredoxin II) is a gene that regulates ROS.

MATERIALS AND METHODS

As the entry point in this study to conduct a bioinformatics analysis of the sequencing results of Prx II^+/+ dermal mesenchymal stem cells (DMSCs) and Prx II^-/- DMSCs. lncRNA/miRNA/mRNA networks were then constructed and preliminarily verified in RT-qPCR experiments.

RESULTS

In this study, a total of 11 hub genes (Gria1, Nrcam, Sox10, Snap25, Cntn2, Dlg2, Ngf, Ntrk3, Amph, Syt1, and Cd24a), eight miRNAs (miRNA-4661, miRNA-34a, miRNA-185, miRNA-34b-5p, miRNA-34c, miRNA-449a, miRNA-449b, miRNA-449c) and 12 lncRNAs (Dubr, Gas5, Gm20427, Gm26917, Gm42547, Gm8066, Kcnq1ot1, Malat1, Mir17hg, Neat1, Rian, and Tug1) were predicted in lncRNA/miRNA/mRNA network.

CONCLUSION

The regulatory mechanism of Prx II in the differentiation of DMSCs into neurons through ROS was explored, and a theoretical basis was determined that can be applied in future research on nervous system diseases and the clinical applications of stem cells.

Bioinformatics Analysis of Novel Targets for Treating Cervical Cancer by Immunotherapy Based on Immune Escape

BACKGROUND/AIM

Cervical cancer (CC) is a high-risk disease in women, and advanced CC can be difficult to treat even with surgery, radiotherapy, and chemotherapy. Hence, developing more effective treatment methods is imperative. Cancer cells undergo a renewal process to escape immune surveillance and then attack the immune system. However, the underlying mechanisms remain unclear. Currently, only one immunotherapy drug has been approved by the Food and Drug Administration for CC, thus indicating the need for and importance of identifying key targets related to immunotherapy.

MATERIALS AND METHODS

Data on CC and normal cervical tissue samples were downloaded from the National Center for Biotechnology Information database. Transcriptome Analysis Console software was used to analyze differentially expressed genes (DEGs) in two sample groups. These DEGs were uploaded to the DAVID online analysis platform to analyze biological processes for which they were enriched. Finally, Cytoscape was used to map protein interaction and hub gene analyses.

RESULTS

A total of 165 up-regulated and 362 down-regulated genes were identified. Among them, 13 hub genes were analyzed in a protein-protein interaction network using the Cytoscape software. The genes were screened out based on the betweenness centrality value and average degree of all nodes. The hub genes were as follows: ANXA1, APOE, AR, C1QC, CALML5, CD47, CTSZ, HSP90AA1, HSP90B1, NOD2, THY1, TLR4, and VIM. We identified the following 12 microRNAs (miRNAs) that target the hub genes: hsa-miR-2110, hsa-miR-92a-2-5p, hsa-miR-520d-5p, hsa-miR-4514, hsa-miR-4692, hsa-miR-499b-5p, hsa-miR-5011-5p, hsa-miR-6847-5p, hsa-miR-8054, hsa-miR-642a-5p, hsa-miR-940, and hsa-miR-6893-5p.

CONCLUSION

Using bioinformatics, we identified potential miRNAs that regulated the cancer-related genes and long noncoding RNAs (lncRNAs) that regulated these miRNAs. We further elucidated the mutual regulation of mRNAs, miRNAs, and lncRNAs involved in CC occurrence and development. These findings may have major applications in the treatment of CC by immunotherapy and the development of drugs against CC.

Lipophagy: A potential therapeutic target for nonalcoholic and alcoholic fatty liver disease

Lipid droplets are unique lipid storage organelles in hepatocytes. Lipophagy is a key mechanism of selective degradation of lipid droplets through lysosomes. It plays a crucial role in the prevention of metabolic liver disease, including nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), and is a potential therapeutic target for treating these dysfunctions. In this review, we highlighted recent research and discussed advances in key proteins and molecular mechanisms related to lipophagy in liver disease. Reactive oxygen species (ROS) is an inevitable product of metabolism in alcohol-treated or high-fat-treated cells. Under this light, the potential role of ROS in autophagy in lipid droplet removal was initially explored to provide insights into the link between oxidative stress and metabolic liver disease. Subsequently, the current measures and drugs that treat NAFLD and AFLD through lipophagy regulation were summarized. The complexity of molecular mechanisms underlying lipophagy in hepatocytes and the need for further studies for their elucidation, as well as the status and limitations of current therapeutic measures and drugs, were also discussed.

Regulatory pathway underpinning the development of encephalitis after simian immunodeficiency virus infection in rhesus macaques (Macaca mulatta)

BACKGROUND

Simian immunodeficiency virus (SIV) infection in rhesus macaques (Macaca mulatta) can lead to the development of SIV encephalitis (SIVE), which is closely related to human immunodeficiency virus (HIV)-induced dementia.

METHODS

This was done by analyzing SIV and SIVE encephalitis in infected M. mulatta hippocampus samples from two microarray data sets, identifying two groups of common differentially expressed genes and predicting associated protein interactions.

RESULTS

We found that eight genes-MX1, B2M, IFIT1, TYMP, STAT1, IFI44, ISG15, and IFI27-affected the negative regulation of biological processes, hepatitis C and Epstein-Barr viral infection, and the toll-like receptor signaling pathway, which mediate the development of encephalitis after SIV infection. In particular, STAT1 played a central role in the process by regulating biopathological changes during the development of SIVE.

CONCLUSION

These findings provide a new theoretical basis for the treatment of encephalopathy after HIV infection by targeting STAT1.

PRDX1 negatively regulates bleomycin-induced pulmonary fibrosis via inhibiting the epithelial-mesenchymal transition and lung fibroblast proliferation in vitro and in vivo

BACKGROUND

Pulmonary fibrosis is a major category of end-stage changes in lung diseases, characterized by lung epithelial cell damage, proliferation of fibroblasts, and accumulation of extracellular matrix. Peroxiredoxin 1 (PRDX1), a member of the peroxiredoxin protein family, participates in the regulation of the levels of reactive oxygen species in cells and various other physiological activities, as well as the occurrence and development of diseases by functioning as a chaperonin.

METHODS

Experimental methods including MTT assay, morphological observation of fibrosis, wound healing assay, fluorescence microscopy, flow cytometry, ELISA, western blot, transcriptome sequencing, and histopathological analysis were used in this study.

RESULTS

PRDX1 knockdown increased ROS levels in lung epithelial cells and promoted epithelial-mesenchymal transition (EMT) through the PI3K/Akt and JNK/Smad signalling pathways. PRDX1 knockout significantly increased TGF-β secretion, ROS production, and cell migration in primary lung fibroblasts. PRDX1 deficiency also increased cell proliferation, cell cycle circulation, and fibrosis progression through the PI3K/Akt and JNK/Smad signalling pathways. BLM treatment induced more severe pulmonary fibrosis in PRDX1-knockout mice, mainly through the PI3K/Akt and JNK/Smad signalling pathways.

CONCLUSIONS

Our findings strongly suggest that PRDX1 is a key molecule in BLM-induced lung fibrosis progression and acts through modulating EMT and lung fibroblast proliferation; therefore, it may be a therapeutic target for the treatment of BLM-induced lung fibrosis.

Network analysis for the identification of hub genes and related molecules as potential biomarkers associated with the differentiation of bone marrow-derived stem cells into hepatocytes

The incidence of liver diseases has been increasing steadily. However, it has some shortcomings, such as high cost and organ donor scarcity. The application of stem cell research has brought new ideas for the treatment of liver diseases. Therefore, it is particularly important to clarify the molecular and regulatory mechanisms of differentiation of bone marrow-derived stem cells (BMSCs) into liver cells. Herein, we screened differentially expressed genes between hepatocytes and untreated BMSCs to identify the genes responsible for the differentiation of BMSCs into hepatocytes. GSE30419 gene microarray data of BMSCs and GSE72088 gene microarray data of primary hepatocytes were obtained from the Gene Expression Omnibus database. Transcriptome Analysis Console software showed that 1896 genes were upregulated and 2506 were downregulated in hepatocytes as compared with BMSCs. Hub genes were analyzed using the STRING and Cytoscape v 3.8.2, revealing that twenty-four hub genes, play a pivotal role in the differentiation of BMSCs into hepatocytes. The expression of the hub genes in the BMSCs and hepatocytes was verified by reverse transcription-quantitative PCR (RT-qPCR). Next, the target miRNAs of hub genes were predicted, and then the lncRNAs regulating miRNAs was discovered, thus forming the lncRNA-miRNA-mRNA interaction chain. The results indicate that the lncRNA-miRNA-mRNA interaction chain may play an important role in the differentiation of BMSCs into hepatocytes, which provides a new therapeutic target for liver disease treatment.

Peroxiredoxin 5 protects HepG2 cells from ethyl β-carboline-3-carboxylate-induced cell death via ROS-dependent MAPK signalling pathways

Peroxiredoxin 5 (PRDX5) is the member of Prxs family, widely reported to be involved in various types of cell death. We previously found that PRDX5 knockdown increases the susceptibility of cell death upon oxidative stress treatment. Ethyl β-carboline-3-carboxylate (β-CCE), an alkaloid extracted from Picrasma quassioides, has been reported to play a role in neuronal disease, but its anti-cancer potential on liver cancers remains unknown. Here, we studied the effect of PRDX5 on ethyl β-carboline-3-carboxylate (β-CCE)-induced apoptosis of hepatomas. High expression level of PRDX5 was deeply related with the postoperative survival of patients with liver cancer, indicating that PRDX5 may be a biomarker of live cancer processing. Moreover, PRDX5 over-expression in HepG2 cells significantly inhibited β-CCE-induced cell apoptosis and cellular ROS levels as well as mitochondrial dysfunction. Signalling pathway analysis showed that β-CCE could significantly up-regulate the ROS-dependent MAPK signalling, which were in turn boosts the mitochondria-dependent cell apoptosis. Moreover, PRDX5 over-expression could reverse the anti-cancer effects induced by β-CCE in HepG2 cells. Our findings suggest that PRDX5 has a protective role on β-CCE-induced liver cancer cell death and provides new insights for using its anti-cancer properties for liver cancer treatment.

Knockdown of Peroxiredoxin V increased the cytotoxicity of non-thermal plasma-treated culture medium to A549 cells

Administration of non-thermal plasma therapy via the use of plasma-activated medium (PAM) might be a novel strategy for cancer treatment, as it induces apoptosis by increasing reactive oxygen species (ROS) levels. Peroxiredoxin V (PRDX5) scavenges ROS and reactive nitrogen species and is known to regulate several physiological and pathological reactions. However, its role in lung cancer cells exposed to PAM is unknown. Here, we investigated the effect of PRDX5 in PAM-treated A549 lung cancer cells and determined the mechanism underlying its cytotoxicity. Cell culture medium was treated with low temperature plasma at 16.4 kV for 0, 60, 120, or 180 s to develop PAM. PRDX5 was knocked down in A549 cells via transfection with short hairpin RNA targeting PRDX5. Colony formation and wound healing assays, flow cytometry, fluorescence microscopy, and western blotting were performed to detect the effect of PRDX5 knockdown on PAM-treated A549 cells. PAM showed higher cytotoxicity in lung cancer cells than in control cells, downregulated the mitogen-activated protein kinase signaling pathway, and induced apoptosis. PRDX5 knockdown significantly inhibited cell colony formation and migration, increased ROS accumulation, and reduced mitochondrial membrane potential in lung cancer cells. Hence, PRDX5 knockdown combined with PAM treatment represents an effective option for lung cancer treatment.

Ethyl β-Carboline-3-Carboxylate Increases Cervical Cancer Cell Apoptosis Through ROS-p38 MAPK Signaling Pathway

BACKGROUND/AIM

Ethyl β-carboline-3-carboxylate (β-CCE) is one of the effective ingredients of Picrasma quassioides (P. quassioides). As a β-carboline alkaloid, it can antagonize the pharmacological effects of benzodiazepines by regulating neurotransmitter secretion through receptors, thus affecting anxiety and physiology. However, its efficacy in cancer treatment is still unclear.

MATERIALS AND METHODS

We explored the effect of b-CCE on SiHa cells using MTT assay, western blot, flow cytometry, LDH release, T-AOC, SOD, and MDA assays.

RESULTS

We investigated the cytotoxicity of β-CCE in SiHa cells and verified that β-CCE could induce cell apoptosis in a time- and concentration-dependent manner. In this process, treatment with β-CCE significantly increased the levels of cytoplasmic and mitochondrial reactive oxygen species (ROS), which disturb the oxidation homeostasis by regulating the total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) production. Notably, the addition of N-acetylcysteine (NAC) (ROS scavenger) effectively alleviated β-CCE-induced apoptosis in SiHa cells. In addition, β-CCE might activate the p38/MAPK signaling pathway, as the pre-treatment with SB203580 (p38 inhibitor) significantly reduced β-CCE-induced apoptosis in SiHa cells.

CONCLUSION

β-CCE has an anti-tumor activity. It activates the p38/MAPK signaling pathway by increasing intracellular ROS levels, which subsequently induce SiHa cell apoptosis. Our results provide a novel therapeutic target for treatment of cervical cancer.

Pharmacological effects of Picrasma quassioides (D. Don) Benn for inflammation, cancer and neuroprotection (Review)

Picrasma quassioides (D. Don) Benn is an Asian shrub with a considerable history of traditional medicinal use. P. quassioides and its extracts exhibit good therapeutic properties against several diseases, including anti-inflammatory, antibacterial and anticancer effects. However, the composition of compounds contained in P. quassioides is complex; although various studies have examined mixtures or individual compounds extracted from it, studies on the application of P. quassioides extracts remain limited. In the present review, the structures and functions of the compounds identified from P. quassioides and their utility in anti-inflammatory, anticancer and neuroprotectant therapies was discussed. The present review provided up-to-date information on pharmacological activities and clinical applications for P. quassioides extracts.

Anticancer Effect of ERM210 on Liver Cancer Cells Through ROS/Mitochondria-dependent Apoptosis Signaling Pathways

BACKGROUND/AIM

Asian Traditional medicines are renowned for their antitumor properties and are efficacious in the clinical treatment of various cancer types. ERM210 is a Korean traditional medicine comprising nine types of medicinal plants. In the present study, we examined the pro-apoptotic effect and molecular mechanisms of the effects of ERM210 on HepG2 liver cancer cells.

MATERIALS AND METHODS

The cytotoxicity of ERM210 on HepG2 cells was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and wound-healing assays, and apoptosis and signaling pathways by fluorescence microscopy flow cytometry and western blotting.

RESULTS

ERM210 significantly impaired HepG2 cell viability and enhanced mitochondria-dependent cellular apoptosis in a time- and dose-dependent manner by up-regulating the expression of caspases 3, 7 and 9, and of BCL2 apoptosis regulator (BCL2)-associated X, apoptosis regulator (BAX) proteins, whilst down-regulating that of BCL2 protein. Furthermore, ERM210 treatment increased accumulation of cellular and mitochondrial reactive oxygen species (ROS) and significantly inhibited cell migration. Additionally, all these phenomena were reversed by treating with the ROS scavenger N-acetylcysteine. The analysis of signaling proteins revealed that ERM210 significantly up-regulated the phosphorylation of ROS-dependent mitogen-activated protein kinases (p38, extracellular-regulated kinase, and c-Jun N-terminal kinase in HepG2 liver cancer cells.

CONCLUSION

ERM210 exerts anticancer effects in HepG2 liver cancer cells by up-regulating ROS/mitochondria-dependent apoptosis signaling, providing new insight into the possibility of employing this traditional medicine for the clinical treatment of liver cancer.

Hispidin inhibits LPS-induced nitric oxide production in BV-2 microglial cells via ROS-dependent MAPK signaling

Neuroinflammation is associated with many neurodegenerative diseases. Abnormal activation of microglial cells in the central nervous system (CNS) is a major characteristic of neuroinflammation. Nitric oxide (NO) free radicals are produced by activated microglia and prolonged presence of large quantities of NO in the CNS can lead to neuroinflammation and disease. Hispidin is a polyphenol derived from Phellinus linteus (a valuable medicinal mushroom) with strong antioxidant, anticancer and antidiabetic properties. A previous study demonstrated that hispidin significantly inhibited NO production via lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Therefore, the present study used MTT assay was used to detect the effect of hispdin on cell viability. Griess reagent analysis was used to measure NO production. Reverse transcription-semi quantitative PCR and western blotting were used to evaluate the effects of hispdin on iNOS mRNA and MAPK/ERK/JNK protein levels. Fluorescence microscopy and flow cytometry were used to detect the effects of hispdin on the production of ROS and phagocytosis of cells. The present results indicated that hispidin could significantly inhibit the increase of NO production and iNOS expression in BV-2 microglial cells stimulated by LPS. The inhibitory effect of hispidin on NO production was similar to that of S-methylisothiourea sulfate, an iNOS inhibitor. Signaling studies demonstrated that hispidin markedly suppresses LPS-induced mitogen activated protein kinases and JAK1/STAT3 activation, although not the NF-κB signaling pathway. The present observations in LPS-stimulated BV-2 microglial cells indicated that hispidin might serve as a therapeutic candidate for the treatment of NO-induced neuroinflammation and, potentially, as a novel iNOS inhibitor.

Curcumin Activates ROS Signaling to Promote Pyroptosis in Hepatocellular Carcinoma HepG2 Cells

BACKGROUND/AIM

Curcumin is a polyphenol that exerts a variety of pharmacological activities and plays an anti-cancer role in many cancer cells. It was recently reported that gasdermin E (GSDME) is involved in the progression of pyroptosis.

MATERIALS AND METHODS

HepG2 cells were treated with various concentrations of curcumin and cell viability was examined using MTT assay, apoptosis was analysed using flow cytometry, reactive oxygen species (ROS) levels using dihydroethidium, LDH release using an LDH cytotoxicity assay, and protein expression using western blot.

RESULTS

Curcumin increased the expression of the GSDME N-terminus and proteins involved in pyrolysis, promoted HspG2 cell pyrolysis and increased intracellular ROS levels. Moreover, inhibition of the production of intracellular ROS with n-acetylcysteine (NAC) improved the degree of apoptosis and pyrolysis induced by curcumin.

CONCLUSION

Curcumin induces HspG2 cell death by increasing apoptosis and pyroptosis, and ROS play a key role in this process. This study improves our understanding of the potential anti-cancer properties of curcumin in liver cancer.

Picrasma quassioides Extract Elevates the Cervical Cancer Cell Apoptosis Through ROS-Mitochondrial Axis Activated p38 MAPK Signaling Pathway

BACKGROUND/AIM

Picrasma quassioides (P. quassioides) is used in traditional Asian medicine widely for the treatment of anemopyretic cold, eczema, nausea, loss of appetite, diabetes mellitus, hypertension etc. In this study we aimed to understand the effect of P. quassioides ethanol extract on SiHa cervical cancer cell apoptosis.

MATERIALS AND METHODS

The P. quassioides extract-induced apoptosis was analyzed using the MTT assay, fluorescence microscopy, flow cytometry and western blotting.

RESULTS

P. quassioides extract induced cellular apoptosis by increasing the accumulation of cellular and mitochondrial reactive oxygen species (ROS) levels and inhibiting ATP synthesis. Pretreatment with N-Acetylcysteine (NAC), a classic antioxidant, decreased the intracellular ROS production and inhibited apoptosis. In addition, the P38 MAPK signaling pathway is a key in the apoptosis of SiHa cells induced by the P. quassioides extract.

CONCLUSION

The P. quassioides extract exerts its anti-cancer properties on SiHa cells through ROS-mitochondria axis and P38 MAPK signaling. Our data provide a new insight for P. quassioides as a therapeutic strategy for cervical cancer treatment.

Peroxiredoxin II with dermal mesenchymal stem cells accelerates wound healing

Peroxiredoxin II (Prx II) is involved in proliferation, differentiation, and aging in various cell types. However, Prx II-mediated stem cell regulation is poorly understood. Here, dermal mesenchymal stem cells (DMSCs), cell-growth factor-rich conditioned medium from DMSCs (DMSC-CM), and DMSC-derived exosomes (DMSC-Exos) were used to explore the regulatory role of Prx II in DMSC wound healing. Following treatment, wound healing was significantly decelerated in Prx II-/- DMSCs than in Prx II+/+ DMSCs. In vitro stimulation with 10 μM H2O2 significantly increased apoptosis in Prx II-/- DMSCs compared with Prx II+/+ DMSCs. The mRNA expression levels of EGF, b-FGF, PDGF-B, and VEGF did not significantly differ between Prx II-/- and Prx II+/+ DMSCs. Fibroblasts proliferated comparably when treated with Prx II+/+ DMSC-CM or Prx II-/- DMSC-CM. Wound healing was significantly higher in the Prx II-/- DMSC-Exos-treated group than in the Prx II+/+ DMSCs-Exos-treated group. Moreover, microRNA (miR)-21-5p expression levels were lower and miR-221 levels were higher in Prx II-/- DMSCs than in Prx II+/+ DMSCs. Therefore, our results indicate that Prx II accelerated wound healing by protecting DMSCs from reactive oxygen species-induced apoptosis; however, Prx II did not regulate cell/growth factor secretion. Prx II potentially regulates exosome functions via miR-21-5p and miR-221.

Peroxiredoxin V Silencing Elevates Susceptibility to Doxorubicin-induced Cell Apoptosis via ROS-dependent Mitochondrial Dysfunction in AGS Gastric Cancer Cells

BACKGROUND/AIM

Peroxiredoxin V (Prx V) plays crucial roles in cellular apoptosis and proliferation in various cancer cells by regulating the cellular reactive oxygen species (ROS) levels.

MATERIALS AND METHODS

Here, we examined the possible regulatory effects of Prx V on doxorubicin (DOX)-induced cellular apoptosis and its mechanisms in the human gastric adenocarcinoma cell line (AGS cells).

RESULTS

Our findings suggest that Prx V knockdown may significantly increase the DOX-induced apoptosis by aggravating intracellular ROS accumulation. We also found that DOX-induced mitochondrial ROS levels and membrane permeability were significantly higher in short hairpin Prx V cells than in mock cells, and these phenomena were dramatically reversed by ROS scavenger treatment. Prx V knockdown also significantly upregulated the cleaved caspase 9, 3, and B-cell lymphoma 2 (Bcl2)-associated agonist of cell death/Bcl2 protein expression levels, suggesting that Prx V knockdown activates mitochondria-dependent apoptotic signaling pathways.

CONCLUSION

Taken together, this study suggests that Prx V may be a strong molecular target for gastric cancer (GC) chemotherapy, and further elucidates the role of Prx V in oxidative stress-induced cell apoptosis.

Regulatory function of peroxiredoxin I on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung cancer development

Smoking is a major cause of lung cancer, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the most important carcinogens in cigarette smoke. NNK modulates the expression of peroxiredoxin (Prdx) I in lung cancer. Prdx1 is upregulated in lung squamous cell carcinoma and lung adenocarcinoma, and considered a potential biomarker for lung cancer. The current article reviewed the role and regulatory mechanisms of Prdx1 in NNK-induced lung cancer cells. Prdx1 protects erythrocytes and DNA from NNK-induced oxidative damage, prevents malignant transformation of cells and promotes cytotoxicity of natural killer cells, hence suppressing tumor formation. In addition, Prdx1 has the ability to prevent NNK-induced lung tumor metabolic activity and generation of large amount of reactive oxygen species (ROS) and ROS-induced apoptosis, thus promoting tumor cell survival. In contrast to this, Prdx1, together with NNK, can promote the epithelial-mesenchymal transition and migration of lung tumor cells. The signaling pathways associated with NNK and Prdx1 in lung cancer cells have been discussed in present review; however, numerous potential pathways are yet to be studied. To develop novel methods for treating NNK-induced lung cancer, and improve the survival rate of patients with lung cancer, further research is needed to understand the complete mechanism associated with NNK.

BRM270 Suppresses Cervical Cancer Stem Cell Characteristics and Progression by Inhibiting SOX2

BACKGROUND/AIM

Cervical cancer is one of the leading causes of cancer death in women worldwide. BRM270 (BRMLife) has therapeutic potential for cancer treatment owing to its ability to inhibit cell proliferation, and expression of cluster of differentiation (CD) 133 in CD133⁺ cancer cells. This study was designed to evaluate the therapeutic effects of plant extract formulation BRM270 against cervical cancer progression.

MATERIALS AND METHODS

The expression of sex-determining region Y-box 2 (SOX2) was tested in four different cervical cancer cell lines, HeLA, SiHa, Caski and C33A. SOX2-expressing SiHa and C33A cell lines were selected for further experiments on the in vitro and in vivo effects of BRM270 on cervical cancer progression using western blotting, flow cytometry, sphere-formation assay, magnetic-activated cell sorting of CD133⁺ cervical cancer cells, and xenografts in female athymic BALB/c nude mice.

RESULTS

In the present study, in cervical cancer stem cells (CSCs), we found that BRM270 inhibited expression of SOX2, which is associated with cervical cancer initiation and metastasis. BRM270 also inhibited CD133 expression and induced apoptosis of CSCs and suppressed CD133⁺ CSC proliferation and sphere formation in vitro as well as SiHa and C33A cell xenograft tumor growth in vivo. This was accompanied by down-regulation of markers of epithelial-to-mesenchymal transition.

CONCLUSION

BRM270 might be an effective agent for cervical cancer treatment.

Wogonin Influences Osteosarcoma Stem Cell Stemness Through ROS-dependent Signaling

Backgorund/Aim: Wogonin, a flavonoid-like compound extracted from the root of Scutellaria baicalensis Georgi, has been shown to have anticancer effects against cancer cells. Osteosarcoma is the most malignant type of bone cancer and can appear in any bone, with a high propensity for relapse and metastasis. The present study aimed to assess the anticancer effects of wogonin on osteosarcoma stem cells.

MATERIALS AND METHODS

The cytotoxic effects of wogonin on CD133⁺ Cal72 osteosarcoma stem cells were assessed through in vitro experiments by MTT assay, transwell assay, sphere-formation assay, flow cytometry, immunocytochemistry and western blotting.

RESULTS

Wogonin suppressed stem cell characteristics and the expression of stem cell-related genes by regulating reactive oxygen species (ROS) levels and ROS-related signaling of CD133⁺ Cal72 cells, effects which were reversed by ROS scavenger N-acetylcysteine.

CONCLUSION

Wogonin may be a promising candidate for successful clinical management of osteosarcoma by regulating ROS-related mechanisms and stem cell-related genes.

The compound 2-benzylthio-5,8-dimethoxynaphthalene-1,4-dione leads to apoptotic cell death by increasing the cellular reactive oxygen species levels in Ras-mutated liver cancer cells

The aim of the present study was to verify the pro-apoptotic anticancer potential of several 5,8-dimethoxy-1,4-phthoquinone (DMNQ) derivatives in Ras-mediated tumorigenesis. MTT assays were used to detect cellular viability and flow cytometry was performed to assess intracellular reactive oxygen species (ROS) levels and apoptosis. The expression levels of proteins were detected via western blotting. Among the 12 newly synthesized DMNQ derivatives, 2-benzylthio-5,8-dimethoxynaphthalene-1,4-dione (BZNQ; component #1) significantly reduced cell viability both in mouse NIH3T3 embryonic fibroblasts cells (NC) and H-Ras^G12V transfected mouse NIH3T3 embryonic fibroblasts cells (NR). Moreover, BZNQ resulted in increased cytotoxic sensitivity in Ras-mutant transfected cells. Furthermore, the reactive oxygen species (ROS) levels in H-Ras^G12V transfected HepG2 liver cancer cells (HR) were significantly higher compared with the levels in HepG2 liver cancer cells (HC) following BZNQ treatment, which further resulted in increased cellular apoptosis. Eliminating cellular ROS using an ROS scavenger N-acetyl-L-cysteine markedly reversed BZNQ-induced cellular ROS accumulation and cell apoptosis in HC and HR cells. Western blotting results revealed that BZNQ significantly downregulated H-Ras protein expression and inhibited the Ras-mediated downstream signaling pathways such as protein kinase B, extracellular signal-related kinase and glycogen synthase kinase phosphorylation and β-catenin protein expression. These results indicated that the novel DMNQ derivative BZNQ may be a therapeutic drug for Ras-mediated liver tumorigenesis. The results of the current study suggest that BZNQ exerts its effect by downregulating H-Ras protein expression and Ras-mediated signaling pathways.

BRM270 targets cancer stem cells and augments chemo-sensitivity in cancer

Over the past decade, a number of studies have demonstrated the resistance of cancer cells to conventional drugs and have recognized this as a major challenge in cancer therapy. While attempting to understand the underlying mechanisms of chemoresistance, several studies have suggested that the presence of cancer stem cells (CSCs) in tumors is one of the major pathways contributing toward resistance. Chemoresistance leads to cancer treatment failure and worsens the prognosis of patients. Natural herbal compounds are gaining attention as an alternative treatment strategy for cancer. These compounds may be effective against chemoresistant cells either alone or synergistically alongside conventional drugs, sensitizing cancer cells and enhancing the therapeutic efficacy. BRM270 is a natural compound made from seven herbal plant (Saururus chinensis, Citrus unshiu Markovich, Aloe vera, Arnebia euchroma, Portulaca oleracea, Prunella vulgaris var. lilacina and Scutellaria bacicalensis) extracts used in Asian traditional medicine and has the potential to target CSCs. Several studies have demonstrated the positive effects of BRM270 against chemoresistant cancer and its synergy alongside existing cancer drugs, including paclitaxel and gefitinib. These effects have been observed against various cancer types, including resistant non-small cell lung cancer (NSCLC), glioblastoma, multi-drug resistant osteosarcoma, cervical cancer, pancreatic cancer and hepatocarcinoma. The present review discusses the effects of BRM270 treatment against CSC-associated chemoresistance in common types of cancer.

Peroxiredoxin II Inhibits Alcohol-induced Apoptosis in L02 Hepatocytes Through AKT/β-Catenin Signaling Pathway

BACKGROUND

Peroxiredoxin II (PRDX2) performs unique roles in cells. It can reduce peroxides through cysteine residues, and helps prevent the effects of oxidative stress on cells. It is closely related to the occurrence and development of various diseases, especially alcoholic liver injury and even liver cancer. The metabolism of alcohol in hepatocytes leads to the increase in the levels of reactive oxygen species (ROS), oxidative stress, injury, and apoptosis. Therefore, this study focused on the investigating the protection conferred by PRDX2 against alcohol-induced apoptosis of hepatocytes.

MATERIALS AND METHODS

PRDX2 inhibition of alcohol-induced apoptosis in L02 hepatocytes was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, fluorescence microscopy, flow cytometry, western blotting and hematoxylin and eosin staining.

RESULTS

The results showed that the levels of reactive oxygen species, protein kinase B, β-catenin, B-cell lymphoma-2 (BCL2), BCL-XL, BCL2-associated X, cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase in PRDX2-silenced cells were increased significantly after the treatment of cells with ethanol. Similar results were obtained in an in vivo Prdx2-knockout mouse model of alcoholic liver injury. Therefore, PRDX2 may regulate the phosphorylation of the AKT signal protein by eliminating reactive oxygen species from cells, and it inhibits the downstream mitochondria-dependent apoptosis pathway, and, thereby, the apoptosis of cells.

CONCLUSION

Thus, PRDX2 may be a potential molecular target for the prevention and treatment of alcoholic liver injury.

Anti-tumor Properties of Picrasma quassioides Extracts in H-RasG12V Liver Cancer Are Mediated Through ROS-dependent Mitochondrial Dysfunction

BACKGROUND

Picrasma quassioides (PQ) is a traditional Asian herbal medicine with anti-tumor properties that can inhibit the viability of HepG2 liver cancer cells. H-Ras is often mutated in liver cancer, however, the effect of PQ treatment on H-Ras mutated liver cancer is unclear. This study aimed to investigate the role of PQ on ROS accumulation and mitochondrial dysfunction in H-ras mutated HepG2 (HepG2^G12V) cells.

MATERIALS AND METHODS

PQ ethanol extract-induced HepG2^G12V apoptosis was analyzed by the MTT assay, fluorescence microscopy, flow cytometry and western blotting.

RESULTS

PQ treatment affected cell migration and colony formation in HepG2^G12V cells. Cleaved-caspase-3, cleaved-caspase-9 and BCL2 associated agonist of cell death (BAD) expression levels were increased, while the levels of B-cell lymphoma-extra large (Bcl-xL) were decreased with PQ treatment. PQ treatment led to a reduction of H-Ras expression levels in liver cancer cells, thus reducing their abnormal proliferation. Furthermore, it led to increased expression levels of Peroxiredoxin VI, which regulates the redox signal in cells.

CONCLUSION

Taken together these results provide a new functional significance for the role of PQ in treating HepG2^G12V liver cancer.

Peroxiredoxin I deficiency increases pancreatic β‑cell apoptosis after streptozotocin stimulation via the AKT/GSK3β signaling pathway

Apoptosis of pancreatic β-cells is involved in the pathogenesis of type I and II diabetes. Peroxiredoxin I (Prx I) serves an important role in regulating cellular apoptosis; however, the role of Prx I in pancreatic β-cell apoptosis is not completely understood. In the present study, the role of peroxiredoxin 1 (Prx I) during streptozotocin (STZ)-induced apoptosis of pancreatic β-cells was investigated. The expression level of Prx I was decreased by STZ treatment in a time-dependent manner, and apoptosis of Prx I knockdown MIN6 cells was increased by STZ stimulation, compared with untransduced MIN6 cells. Furthermore, an intraperitoneal injection of STZ increased pancreatic islet damage in Prx I knockout mice, compared with wild-type and Prx II knockout mice. AKT and glycogen synthase kinase (GSK)-3β phosphorylation significantly decreased following Prx I knockdown in MIN6 cells. However, phosphorylated β-catenin and p65 levels significantly increased after STZ stimulation, compared with untransduced cells. The results of the present study indicate that deletion of Prx I mediated STZ-induced pancreatic β-cell death in vivo and in vitro by regulating the AKT/GSK-3β/β-catenin signaling pathway, as well as NF-κB signaling. These findings provide a theoretical basis for treatment of pancreatic damage.

Peroxiredoxin I deficiency increases keratinocyte apoptosis in a skin tumor model via the ROS-p38 MAPK pathway

Keratinocyte hyperproliferation is an essential link in skin cancer pathogenesis. Peroxiredoxin I (Prx I) is known to regulate cancer cell proliferation, differentiation, and apoptosis, but its role in skin cancer remains unclear. This study aimed to elucidate the role and mechanism of Prx I in skin cancer pathogenesis. Dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were used to create a skin tumor model of the initiation/promotion stage of cancer. The role of Prx I in H₂O₂-induced keratinocyte apoptosis was also investigated. After DMBA/TPA treatment, Prx I deficiency was significantly associated with less skin tumors, lower Bcl-2 expression, and higher p-p38 and cleaved caspase-3 expressions in Prx I knockout tumors than in wild-type controls. H₂O₂ stimulation caused more cellular apoptosis in Prx I knockdown HaCaT cells than in normal HaCaT cells. The signaling study revealed that Bcl-2, p-p38, and cleaved caspase-3 expressions were consistent with the results in the tumors. In conclusion, the deletion of Prx I triggered the DMBA/TPA-induced skin tumor formation in vivo and in vitro by regulating the reactive oxygen species (ROS)-p38 mitogen-activated protein kinase (MAPK) pathway. These findings provide a theoretical basis for treating skin cancer.

Deletion of Peroxiredoxin II Inhibits the Growth of Mouse Primary Mesenchymal Stem Cells Through Induction of the G0/G1 Cell-cycle Arrest and Activation of AKT/GSK3β/β-Catenin Signaling

BACKGROUND/AIM

Dermal mesenchymal stem cells (DMSCs) are pluripotent stem cells found in the skin which maintain the thickness of the dermal layer and participate in skin wound healing.

MATERIALS AND METHODS

The MTT assay was performed to detect cell proliferation and cell-cycle progression and cell-surface markers were assessed by flow cytometry. The levels of proteins in related signaling pathways were detected by western blotting assay and the translocation of β-catenin into the nucleus were detected by immunofluorescence. Red oil O staining was performed to examine the differentiational ability of DMSCs.

RESULTS

Knockout of PRDX2 inhibited DMSC cell growth, and cell-cycle arrest at G₀/G₁ phase; p16, p21 and cyclin D1 expression levels in Prdx2 knockout DMSCs were significantly increased. Furthermore, AKT phosphorylation were significantly increased in Prdx2 knockout DMSCs, GSK3β activity were inhibited, result in β-Catenin accumulated in the nucleus.

CONCLUSION

In conclusion, these results demonstrated that PRDX2 plays a pivotal role in regulating the proliferation of DMSCs, and this is closely related to the AKT/glycogen synthase kinase 3 beta/β-catenin signaling pathway.

Non-thermal Plasma-activated Medium Induces Apoptosis of Aspc1 Cells Through the ROS-dependent Autophagy Pathway

BACKGROUND/AIM

Numerous studies on various cancer cell lines have reported that direct exposure to non-thermal plasma treatment using plasma-activated medium (PAM) can be applied as a novel technology for cancer therapy. In this study, we investigated the inhibitory effects of PAM on Aspc1 pancreatic cancer cells and the mechanisms responsible for the cell death observed.

MATERIALS AND METHODS

A colony-formation, sphere-formation, wound-healing and transwell assays, immunocytochemistry and western blot analysis were used monitor effects of PAM.

RESULTS

PAM induced a greater cytotoxic effect in pancreatic cancer cells compared to that induced in NIH3T3 cells and 293T cells, and significantly inhibited colony and sphere formation, and cell migration of Aspc1 cells. Furthermore, PAM treatment increased the accumulation of reactive oxygen species (ROS) and reduced the mitochondrial membrane potential in Aspc1 cells. In addition, PAM treatment down-regulated the AKT serine/threonine kinase 1/signal transducer and activator of transcription 3 signaling pathway and induced ROS-dependent cellular autophagy.

CONCLUSION

Our findings suggest that PAM can induce apoptosis of Aspc1 cells through ROS-dependent autophagy and may be a candidate for use in pancreatic cancer therapeutics.

Peroxiredoxin V Inhibits Emodin-induced Gastric Cancer Cell Apoptosis via the ROS/Bcl2 Pathway

BACKGROUND/AIM

Peroxiredoxin (Prx) protein family is aberrantly expressed in various cancers including gastric cancer. Among the six family members, Prx V has been known as an antioxidant enzyme which scavenges intracellular reactive oxygen species (ROS) and modulates cellular apoptosis. This study aimed at investigating the role of Prx V in apoptosis of gastric cancer cells.

MATERIALS AND METHODS

Stably constructed Prx V knockdown, over-expression and mock AGS cells (a human gastric adenocarcinoma cell line) were used to study the effect of Prx V on emodin-induced apoptosis by western blotting, cell viability, apoptosis and ROS detection assays.

RESULTS

Overexpression of Prx V significantly decreased emodin-induced cellular apoptosis and ROS levels compared to Mock and Prx V knockdown AGS cells. Also, overexpression of Prx V down-regulated the expression of pro-apoptotic proteins, Bad and cleaved PARP, and increased the expression of anti-apoptotic protein, Bcl2.

CONCLUSION

Prx V suppresses AGS cell apoptosis via scavenging intracellular ROS and modulating apoptosis-related markers.

Shikonin-induced Apoptosis of Colon Cancer Cells Is Reduced by Peroxiredoxin V Expression

BACKGROUND/AIM

Colon cancer is the second most common deadliest malignancy in the world and better understanding of its underlying mechanisms is needed to improve clinical management. Natural plant extracts are gaining attention in the development of new therapeutic strategies against various cancer types. Shikonin is a naturally extracted naphthoquinone pigment with effects against cancer, including colon cancer.

MATERIALS AND METHODS

In this study, we conducted a series of in vitro experiments to show the effects of Shikonin on colon cancer cell apoptosis. A colon cancer cell line with overexpression of peroxiredoxin V (PrxV) was constructed and the relationship of PrxV expression with Shikonin-induced cell apoptosis was investigated.

RESULTS

Shikonin induced colon cancer cell apoptosis via regulation of mammalian target of rapamycin signaling. Shikonin-induced cell apoptosis was abrogated by overexpression of PrxV.

CONCLUSION

According to the results obtained in this study, targeting PrxV may provide new insight for the successful management of colon cancer by inducing cell apoptosis.

Peroxiredoxin V Reduces β-Lapachone-induced Apoptosis of Colon Cancer Cells

BACKGROUND/AIM

Peroxiredoxin (Prx) V has been known as an antioxidant enzyme which scavenges intracellular reactive oxygen species (ROS). Also, Prx V has been shown to mediate cell apoptosis in various cancers. However, the mechanism of Prx V-induced apoptosis in colon cancer cells remains unknown. Thus, in this study we analyzed the effects of Prx V in β-lapachone-induced apoptosis in SW480 human colon cancer cells.

MATERIALS AND METHODS

β-lapachone-induced apoptosis was analyzed by the MTT assay, western blotting, fluorescence microscopy, Annexin V staining and flow cytometry.

RESULTS

Overexpression of Prx V, significantly decreased β-lapachone-induced cellular apoptosis and Prx V silencing increased β-lapachone-induced cellular apoptosis via modulating ROS scavenging activity compared to mock SW480 cells. In addition, to further explore the mechanism of Prx V regulated β-lapachone-induced SW480 cells apoptosis, the Wnt/β-catenin signaling was studied. The Wnt/ β-catenin signaling pathway was found to be induced by β-lapachone.

CONCLUSION

Prx V regulates SW480 cell apoptosis via scavenging ROS cellular levels and mediating the Wnt/β-catenin signaling pathway, which was induced by β-lapachone.

Pathogenesis, Early Diagnosis, and Therapeutic Management of Alcoholic Liver Disease

Alcoholic liver disease (ALD) refers to the damages to the liver and its functions due to alcohol overconsumption. It consists of fatty liver/steatosis, alcoholic hepatitis, steatohepatitis, chronic hepatitis with liver fibrosis or cirrhosis, and hepatocellular carcinoma. However, the mechanisms behind the pathogenesis of alcoholic liver disease are extremely complicated due to the involvement of immune cells, adipose tissues, and genetic diversity. Clinically, the diagnosis of ALD is not yet well developed. Therefore, the number of patients in advanced stages has increased due to the failure of proper early detection and treatment. At present, abstinence and nutritional therapy remain the conventional therapeutic interventions for ALD. Moreover, the therapies which target the TNF receptor superfamily, hormones, antioxidant signals, and MicroRNAs are used as treatments for ALD. In particular, mesenchymal stem cells (MSCs) are gaining attention as a potential therapeutic target of ALD. Therefore, in this review, we have summarized the current understandings of the pathogenesis and diagnosis of ALD. Moreover, we also discuss the various existing treatment strategies while focusing on promising therapeutic approaches for ALD.

Protective Role of Peroxiredoxin I in Heat-Killed Staphylococcus Aureus-infected Mice

BACKGROUND/AIM

Staphylococcus aureus (S. aureus) is a major gram-positive pathogen, which can cause toxic and immunogenic injuries both in nosocomial and community-acquired infections. Peroxiredoxin (Prx) I plays crucial roles in cellular apoptosis, proliferation, and signal transduction as well as in immunoregulation. The present study aimed to investigate whether Prx I protects mice from death caused by the heat-killed Staphylococcus aureus.

MATERIALS AND METHODS

In the present study, we challenged the wild-type and Prx I-deficient mice with heat-killed S. aureus (HKSA). The effects of Prx I were evaluated by a series of in vitro and in vivo experiments including western blot, Haematoxylin and Eosin staining, splenocyte analysis and cytokines analysis.

RESULTS

Intra-peritoneal (ip) inoculation of HKSA resulted in increased mortality of Prx I-knockout (KO) mice with severe liver damage and highly populated spleens with lymphocytes. Furthermore, HKSA infections also bursted the production of both pro-inflammatory and anti-inflammatory serum cytokines in Prx I KO compared to wild-type mice.

CONCLUSION

Enhanced mortality of S. aureus-infected mice with Prx I deficiency suggested that Prx I may protect against the infection-associated lethality of mice.

Novel 1,4‑naphthoquinone derivatives induce reactive oxygen species‑mediated apoptosis in liver cancer cells

Derivatives of 1,4-naphthoquinone have excellent anti-cancer effects, but their use has been greatly limited due to their serious side effects. To develop compounds with decreased side effects and improved anti-cancer activity, two novel types of 1,4-naphthoquinone derivatives, 2,3-dihydro-2,3-epoxy-2-propylsulfonyl-5,8-dimethoxy-1,4-naphthoquinone (EPDMNQ) and 2,3-dihydro-2,3-epoxy-2-nonylsulfonyl-5,8-dimethoxy-1,4-naphthoquinone (ENDMNQ) were synthesized and their anti-tumor activities were investigated. The effects of EPDMNQ and ENDMNQ on cell viability, apoptosis and accumulation of reactive oxygen species (ROS) in liver cancer cells were determined by MTT cell viability assay and flow cytometry. The expression levels of mitochondrial, mitogen activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling pathway-associated proteins in Hep3B liver cancer cells were analyzed by western blot analysis. The results demonstrated that EPDMNQ and ENDMNQ inhibited the proliferation of liver cancer Hep3B, HepG2, and Huh7 cell lines but not that of normal liver L-02, normal lung IMR-90 and stomach GES-1 cell lines. The number of apoptotic cells and ROS levels were significantly increased following treatment with EPDMNQ and ENDMNQ, and these effects were blocked by the ROS inhibitor N-acetyl-L-cysteine (NAC) in Hep3B cells. EPDMNQ and ENDMNQ induced apoptosis by upregulating the protein expression of p38 MAPK and c-Jun N-terminal kinase and downregulating extracellular signal-regulated kinase and STAT3; these effects were inhibited by NAC. The results of the present study demonstrated that EPDMNQ and ENDMNQ induced apoptosis through ROS-modulated MAPK and STAT3 signaling pathways in Hep3B cells. Therefore, these novel 1,4-naphthoquinone derivatives may be useful as anticancer agents for the treatment of liver cancer.

Cryptotanshinone induces reactive oxygen species‑mediated apoptosis in human rheumatoid arthritis fibroblast‑like synoviocytes

The present study investigated the mechanisms of apoptosis induced by cryptotanshinone (CT) in human rheumatoid arthritis fibroblast‑like synoviocytes (RA‑FLSs). Cell Counting kit‑8 assay was performed to determine the cytotoxic effects of CT in human RA‑FLSs, including primary RA‑FLS, HFLS‑RA and MH7A cells, and in HFLS cells derived from normal synovial tissue. Annexin V‑FITC/PI staining was used to detect the apoptotic effects of CT in HFLS‑RA and MH7A cells. Flow cytometry was performed to detect the apoptotic and reactive oxygen species (ROS) levels induced by CT in HFLS‑RA cells. Western blotting was used to assess the expression levels of proteins associated with apoptosis and with the mitogen‑activated protein kinase (MAPK), protein kinase B (Akt), and signal transducer and activator of transcription‑3 (STAT3) signaling pathways. The results demonstrated that CT treatment significantly suppressed HFLS‑RA and MH7A cell growth, whereas no clear inhibitory effect was observed in normal HFLS cells. CT exposure downregulated the expression levels of B‑cell lymphoma 2 (Bcl‑2), p‑Akt, p‑extracellular signal‑related kinase and p‑STAT3, while it upregulated the expression levels of Bcl‑2‑associated death promoter (Bad), caspase‑3, poly (ADP‑ribose) polymerase (PARP), p‑p38 and p‑c‑Jun N‑terminal kinase. Following ROS scavenging, the CT‑induced apoptosis and altered expression levels of Bcl‑2, Bad, cleaved caspase‑3 and cleaved PARP were restored. Furthermore, the Akt, MAPK and STAT3 signaling pathways were regulated by intracellular ROS. These results suggest that ROS‑mediated Akt, MAPK and STAT3 signaling pathways serve important roles in the CT‑induced apoptosis of RA‑FLSs.

The compound 2-(naphthalene-2-thio)-5,8-dimethoxy-1,4-naphthoquinone induces apoptosis via reactive oxygen species-regulated mitogen-activated protein kinase, protein kinase B, and signal transducer and activator of transcription 3 signaling in human gastric cancer cells

Hit, Lead & Candidate Discovery It is reported that 1,4-naphthoquinones and their derivatives have potent antitumor activity in various cancers, although their clinical application is limited by observed side effects. To improve the therapeutic efficacy of naphthoquinones in the treatment of cancer and to reduce side effects, we synthesized a novel naphthoquinone derivative, 2-(naphthalene-2-thio)-5,8-dimethoxy-1,4-naphthoquinone (NTDMNQ). In this study, we explored the effects of NTDMNQ on apoptosis in gastric cancer cells with a focus on reactive oxygen species (ROS) production. Our results demonstrated that NTDMNQ exhibited the cytotoxic effects on gastric cancer cells in a dose-dependent manner. NTDMNQ significantly induced mitochondrial-related apoptosis in AGS cells and increased the accumulation of ROS. However, pre-treatment with N-acetyl-L-cysteine (NAC), an ROS scavenger, inhibited the NTDMNQ-induced apoptosis. In addition, NTDMNQ increased the phosphorylation of p38 kinase and c-Jun N-terminal kinase (JNK) and decreased the phosphorylation of extracellular signal-regulated kinase (ERK), protein kinase B (Akt), and Signal Transducer and Activator of Transcription 3 (STAT3); these effects were blocked by mitogen-activated protein kinase (MAPK) inhibitor and NAC. Taken together, the present findings indicate that NTDMNQ-induced gastric cancer cell apoptosis via ROS-mediated regulation of the MAPK, Akt, and STAT3 signaling pathways. Therefore, NTDMNQ may be a potential treatment for gastric cancer as well as other tumor types.

Peroxiredoxin I deficiency increases LPS‑induced lethal shock in mice

Peroxiredoxin I (Prx I) plays a role in regulating macrophage proinflammatory cytokine production and gene expression and participates in immune regulation. However, the possible protective role of Prx I in endotoxin‑induced lethal shock is poorly understood. In the present study, western blot analysis, ELISA and haematoxylin and eosin staining were performed to examine the protein expression of cytoines and analyses the levels of cytokines in the serum and tissue to evaluate the tissue damage. The present study revealed that lipopolysaccharide (LPS)‑induced lethality in Prx I‑/‑ mice was is accelerated via the observed decreased serum IL‑10 levels. Results also demonstrated rapid immune cell infiltration and oxidative stress in the Prx I‑/‑mice liver after LPS injections. These phenomena increased liver apoptosis through increasing cleaved caspase‑3 protein expression in Prx I‑/‑ mice after LPS injections, resulting in high lethality after LPS challenges. These findings provide a new insight for understanding the function of Prx I against endotoxin‑induced injury.

Quinalizarin Induces Apoptosis through Reactive Oxygen Species (ROS)-Mediated Mitogen-Activated Protein Kinase (MAPK) and Signal Transducer and Activator of Transcription 3 (STAT3) Signaling Pathways in Colorectal Cancer Cells

BACKGROUND Quinalizarin (1,2,5,8-tetrahydroxyanthraquinone) exhibits potentially useful anticancer effects by inducing apoptosis in several types of cancer, but its underlying mechanism of action remains unknown. The present study examined the effects of quinalizarin on the induction of cell cycle arrest, apoptosis, the generation of reactive oxygen species (ROS), other underlying mechanisms, and its role in modifying colorectal cancer cell lines. MATERIAL AND METHODS The MTT assay was used to evaluate the viability of SW480 and HCT-116 cells that had been treated with quinalizarin and 5-fluorouracil (5-FU). Cell cycle arrest and apoptosis were analyzed by flow cytometry. Western blotting was used to investigate the mitochondrial pathway; Akt, MAPK, and STAT3 signaling pathways were also investigated. The relationship between ROS generation and apoptosis was analyzed by flow cytometry and western blotting. RESULTS The results indicated that quinalizarin significantly inhibits the viability of SW480 and HCT-116 cells in a dose-dependent manner. Quinalizarin induced SW480 cell cycle arrest at G2/M by regulating cyclin B1 and CDK1/2. The apoptosis-related protein expression levels of p-p53, Bad, cleaved caspase-3, cleaved PARP and p-JNK were increased in quinalizarin-treated cells, while protein expression levels Bcl-2, p-Akt, p-ERK, and p-STAT3 were decreased. Quinalizarin induced apoptosis in colorectal cancer cells by regulating MAPK and STAT3 signaling pathways via ROS generation. CONCLUSIONS Quinalizarin induces apoptosis via ROS-mediated MAPK/STAT3 signaling pathways.

Knockdown of peroxiredoxin V increases glutamate‑induced apoptosis in HT22 hippocampal neuron cells

High concentrations of glutamate may mediate neuronal cell apoptosis by increasing intracellular reactive oxygen species (ROS) levels. Peroxiredoxin V (Prx V), a member of the Prx family, serves crucial roles in protecting cells from oxidative stress. The present study investigated the regulatory effect of Prx V on glutamate‑induced effects on viability and apoptosis in HT22 cells. Western blotting was used for protein expression analysis and Annexin V/PI staining and flow cytometry for determination of apoptosis. The results demonstrated that glutamate may ROS‑dependently increase HT22 cell apoptosis and upregulate Prx V protein levels. Furthermore, knockdown of Prx V protein expression with a lentivirus significantly enhanced HT22 cell apoptosis mediated by glutamate, which was reversed by inhibition of ROS with N‑acetyl‑L‑cysteine. Inhibiting the extracellular signal‑regulated kinase (ERK) signaling pathway with PD98059, a specific inhibitor for ERK phosphorylation, markedly decreased glutamate‑induced HT22 cell apoptosis in Prx V knockdown cells, indicating the potential involvement of ERK signaling in glutamate‑induced HT22 cell apoptosis. In addition, an increase in nuclear apoptosis‑inducing factor was observed in Prx V knockdown HT22 cells following glutamate treatment, compared with mock cells, whereas no differences in B‑cell lymphoma‑2 and cleaved‑caspase‑3 protein expression levels were observed between mock and Prx V knockdown cells. The results of the present study indicated that Prx V may have potential as a therapeutic molecular target for glutamate‑induced neuronal cell death and provide novel insight into the role of Prx V in oxidative‑stress induced neuronal cell death.

Peroxiredoxin I is important for cancer-cell survival in Ras-induced hepatic tumorigenesis

Peroxiredoxin I (Prx I), an antioxidant enzyme, has multiple functions in human cancer. However, the role of Prx I in hepatic tumorigenesis has not been characterized. Here we investigated the relevance and underlying mechanism of Prx I in hepatic tumorigenesis. Prx I increased in tumors of hepatocellular carcinoma (HCC) patients that aligned with overexpression of oncogenic H-ras. Prx I also increased in H-ras^G12V transfected HCC cells and liver tumors of H-ras^G12V transgenic (Tg) mice, indicating that Prx I may be involved in Ras-induced hepatic tumorigenesis. When Prx I was knocked down or deleted in HCC-H-ras^G12V cells or H-ras^G12V Tg mice, cell colony or tumor formation was significantly reduced that was associated with downregulation of pERK pathway as well as increased intracellular reactive oxygen species (ROS) induced DNA damage and cell death. Overexpressing Prx I markedly increased Ras downstream pERK/FoxM1/Nrf2 signaling pathway and inhibited oxidative damage in HCC cells and H-ras^G12V Tg mice. In this study, we found Nrf2 was transcriptionally activated by FoxM1, and Prx I was activated by the H-ras^G12V/pERK/FoxM1/Nrf2 pathway and suppressed ROS-induced hepatic cancer-cell death along with formation of a positive feedback loop with Ras/ERK/FoxM1/Nrf2 to promote hepatic tumorigenesis.