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.

Peroxiredoxin II exerts neuroprotective effects by inhibiting endoplasmic reticulum stress and oxidative stress-induced neuronal pyroptosis.

BACKGROUND: Intracerebral hemorrhage (ICH) is a critical neurological condition with few treatment options, where secondary immune responses and specific cell death forms, like pyroptosis, worsen brain damage. Pyroptosis involves gasdermin-mediated membrane pores, increasing inflammation and neural harm, with the NLRP3/Caspase-1/GSDMD pathway being central to this process. Peroxiredoxin II (Prx II), recognized for its mitochondrial protection and reactive oxygen species (ROS) scavenging abilities, appears as a promising neuronal pyroptosis modulator. However, its exact role and action mechanisms need clearer definition. This research aims to explore Prx II impact on neuronal pyroptosis and elucidate its mechanisms, especially regarding endoplasmic reticulum (ER) stress and oxidative stress-induced neuronal damage modulation. METHODS AND RESULTS: Utilizing MTT assays, Microscopy, Hoechst/PI staining, Western blotting, and immunofluorescence, we found Prx II effectively reduces LPS/ATP-induced pyroptosis and neuroinflammation in HT22 hippocampal neuronal cells. Our results indicate Prx II's neuroprotective actions are mediated through PI3K/AKT activation and ER stress pathway inhibition, diminishing mitochondrial dysfunction and decreasing neuronal pyroptosis through the ROS/MAPK/NF-κB pathway. These findings highlight Prx II potential therapeutic value in improving intracerebral hemorrhage outcomes by lessening secondary brain injury via critical signaling pathway modulation involved in neuronal pyroptosis. CONCLUSIONS: Our study not only underlines Prx II importance in neuroprotection but also opens new therapeutic intervention avenues in intracerebral hemorrhage, stressing the complex interplay between redox regulation, ER stress, and mitochondrial dynamics in neuroinflammation and cell death management.

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.

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.

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.

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.

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-ß 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.

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.

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.

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.

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.

Dominant role of peroxiredoxin/JNK axis in stemness regulation during neurogenesis from embryonic stem cells.

Redox balance has been suggested as an important determinant of "stemness" in embryonic stem cells (ESCs). In this study, we demonstrate that peroxiredoxin (Prx) plays a pivotal role in maintenance of ESC stemness during neurogenesis through suppression of reactive oxygen species (ROS)-sensitive signaling. During neurogenesis, Prx I and Oct4 are expressed in a mutually dependent manner and their expression is abruptly downregulated by an excess of ROS. Thus, in Prx I(-/-) or Prx II(-/-) ESCs, rapid loss of stemness can occur due to spontaneous ROS overload, leading to their active commitment into neurons; however, stemness is restored by the addition of an antioxidant or an inhibitor of c-Jun N-terminal kinase (JNK). In addition, Prx I and Prx II appear to have a tight association with the mechanism underlying the protection of ESC stemness in developing teratomas. These results suggest that Prx functions as a protector of ESC stemness by opposing ROS/JNK cascades during neurogenesis. Therefore, our findings have important implications for understanding of maintenance of ESC stemness through involvement of antioxidant enzymes and may lead to development of an alternative stem cell-based therapeutic strategy for production of high-quality neurons in large quantity.

16α,17α-Epoxypregnenolone-20-oxime prevent LPS-induced NO production and iNOS expression in BV-2 microglial cells by inhibiting JNK phosphorylation.

The free radical nitric oxide (NO), a main member of neuroinflammatory cytokine and a gaseous molecule produced by activated microglia, has many physiological functions, including neuroinflammation. In the present study, we evaluated the effects of serial 16-dehydropregnenolone-3-acetate derivatives on lipopolysaccharide (LPS)-induced NO production and inducible nitric oxide synthase (iNOS) expression in BV-2 microglial cells. Among the six derivatives tested, the increases in NO production and iNOS expression observed in BV-2 microglial cells after LPS stimulation were significantly inhibited by treatment with 16α, 17α-epoxypregnenolone-20-oxime. Moreover, the inhibitory effect of 16α,17α-epoxypregnenolone-20-oxime on NO production was similar to that of S-methylisothiourea sulfate (SMT), an iNOS inhibitor. Further studies showed that 16α,17α-epoxypregnenolone-20-oxime inhibited c-Jun N-terminal kinase (JNK) phosphorylation but not inhibitor kappa B (IκB)-α degradation. Our data in LPS-stimulated microglia cells suggest that 16α,17α-epoxypregnenolone-20-oxime might be a candidate therapeutic for treatment of NO induced neuroinflammation and could be a novel iNOS inhibitor.

Hispidin Increases Cell Apoptosis and Ferroptosis in Prostate Cancer Cells Through Phosphatidylinositol-3-Kinase and Mitogen-activated Protein Kinase Signaling Pathway.

BACKGROUND/AIM: Chemotherapy is mainly used in the clinical treatment of prostate cancer. Different anticancer mechanisms can induce cell death in various cancers. Reactive oxygen species (ROS) play crucial roles in cell proliferation, differentiation, apoptosis, and signal transduction. It is widely accepted that ROS accumulation is closely related to chemical drug-induced cancer cell death. MATERIALS AND METHODS: We utilized the MTT assay to detect changes in cell proliferation. Additionally, colony formation and wound healing assay were conducted to investigate the effect of hispidin on cell colony formation and migration ability. Fluorescence microscopy was used to detect intracellular and mitochondrial ROS levels, while western blot was used for detection of cell apoptosis. RESULTS: Hispidin treatment significantly decreased viability of PC3 and DU145 cancer cells but exhibited no cytotoxicity in WPMY-1 cells. Furthermore, hispidin treatment inhibited cell migration and colony formation and triggered cellular and mitochondrial ROS accumulation, leading to mitochondrial dysfunction and mitochondrion-dependent apoptosis. Moreover, hispidin treatment induced ferroptosis in PC3 cells. Scavenging of ROS with N-acetyl cysteine significantly inhibited hispidin-induced apoptosis by altering the expression of apoptosis-related proteins, such as cleaved caspase-3, 9, Bax, and Bcl2. Furthermore, hispidin treatment dramatically up-regulated MAPK (involving p38, ERK, and JNK proteins) and NF-kB signaling pathways while down-regulating AKT phosphorylation. Hispidin treatment also inhibited ferroptosis signaling pathways (involving P53, Nrf-2, and HO-1 proteins) in PC3 cells. In addition, inhibiting these signaling pathways via treatment with specific inhibitors significantly reversed hispidin-induced apoptosis, cellular ROS levels, mitochondrial dysfunction, and ferroptosis. CONCLUSION: Hispidin may represent a potential candidate for treating prostate cancer.

Peroxiredoxin I and II as novel therapeutic molecular targets in cervical cancer treatment through regulation of endoplasmic reticulum stress induced by bleomycin.

Cervical cancer, significantly affecting women worldwide, often involves treatment with bleomycin, an anticancer agent targeting breast, ovarian, and cervical cancers by generating reactive oxygen species (ROS) to induce cancer cell death. The Peroxiredoxin (PRDX) family, particularly PRDX1 and 2, plays a vital role in maintaining cellular balance by scavenging ROS, thus mitigating the damaging effects of bleomycin-induced mitochondrial and cellular oxidative stress. This process reduces endoplasmic reticulum (ER) stress and prevents cell apoptosis. However, reducing PRDX1 and 2 levels reverses their protective effect, increasing apoptosis. This research highlights the importance of PRDX1 and 2 in cervical cancer treatments with bleomycin, showing their potential to enhance treatment efficacy by managing ROS and ER stress and suggesting a therapeutic strategy for improving outcomes in cervical cancer treatment.

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.

Human microRNA-27a* targets Prf1 and GzmB expression to regulate NK-cell cytotoxicity.

Perforin (Prf1) and granzyme B (GzmB) are essential effector molecules for natural killer (NK)-cell cytotoxicity, but how Prf1 and GzmB expression is regulated during arming of NK cells is poorly defined. We show that human microRNA (miR)-27a* is a negative regulator of NK-cell cytotoxicity by silencing Prf1 and GzmB expression. Human miR-27a* specifically bound to the 3' untranslated regions of Prf1 and GzmB, down-regulating expression in both resting and activated NK cells, and it functioned as a fine-tuner for homeostasis of the net amount of the effector proteins. Consistent with miR-27a* having an inhibitory role, knockdown of miR-27a* in NK cells dramatically increased cytotoxicity in vitro and decreased tumor growth in a human tumor xenograft model. Thus, NK-cell cytotoxicity is regulated, in part, by microRNA, and modulating endogenous miR-27a* levels in NK cells represents a potential immunotherapeutic strategy.

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.