Stress-responsive protein kinases in redox-regulated apoptosis signaling

Dihydrotanshinone I potentiates the anti-tumor activity of cisplatin by activating ROS-mediated ER stress through targeting HSPD1 in lung cancer cells

Lung cancer represents one of the most lethal malignancies, characterized by the highest incidence and mortality rates globally. Cisplatin-based chemotherapy exerts powerful anti-tumor activities in lung cancer, whereas its clinical application was limited due to the severe side effects. Dihydrotanshinone I (DHTS), a root extract from Salvia miltiorrhiza, exhibits diverse biological functions, encompassing liver protection, anti-inflammatory properties, promotion of osteoclast differentiation, and induction of apoptosis in tumor cells. DHTS exerts anti-tumor effects in various cancers, however, its biological functions in lung cancer are largely unknown. We demonstrated that DHTS synergistically increased the tumor suppressive effects of cisplatin in lung cancer cells by activating reactive oxygen species (ROS)-mediated endoplasmic reticulum stress (ER stress) and c-Jun N-terminal kinase (JNK) signaling pathways, both in vitro and in vivo. Additionally, DHTS induced excessive ROS accumulation by inhibiting the expression of Heat Shock Proteins 60 (HSPD1). Silencing HSPD1 augmented the anti-tumor effects of DHTS in lung cancer cells, primarily through the stimulation of ROS-mediated ER stress and JNK pathways. Our study suggests that DHTS possesses druggable potential, and combined therapy with DHTS and cisplatin may be a promising therapeutic strategy for certain lung cancer patients.

Endogenous nitric oxide promotes Staphylococcus aureus virulence by activating autophagy

Endogenous nitric oxide (NO) is a small molecule that has been demonstrated to affect the physiology and survival of bacteria. The role of endogenous NO for Staphylococcus aureus survival inside host cells remains unclear. Here, we show that the production of endogenous NO by bacterial nitrate reductase (NR) is affected by molybdopterin biosynthesis protein A (MoeA), which is essential for molybdenum cofactor synthesis in S. aureus. During the infection, the production of endogenous NO promotes S. aureus survival inside macrophages by initiating cellular autophagy. Mechanistically, bacterial endogenous NO can modify the host regulatory protein thioredoxin vis S-nitrosylation, subsequently triggering the phosphorylation of the JNK-Bcl-2 pathway and promoting the initiation of autophagy through the release of Beclin1. Moreover, we confirmed the critical role of MoeA in bacterial survival in vivo by using bloodstream infection, pneumonia, and skin abscess model on both wild-type and autophagy-deficient mice. Interestingly, we observed the significantly increased production of NO and activation of cellular autophagy of sequence type (ST)5 compared with ST239, suggesting that the initiation of autophagy is involved in the clone shift of S. aureus. Our data offered new insights on the role of bacterial endogenous NO in regulating the host signal pathway during infection inside host cells.IMPORTANCEUnderstanding the mechanism underlying Staphylococcus aureus pathogenesis is essential for developing innovative strategies for the prevention and treatment of infection. In this study, we underscore the critical role of molybdopterin biosynthesis protein A and nitric oxide (NO) in inducing autophagy during S. aureus survival within macrophage and in vivo infection. We demonstrate that host regulatory protein can be modified by bacterial metabolites, which may influence cellular processes. Furthermore, our findings indicated that increased endogenous NO production may contribute to the stable prevalence of S. aureus ST5 in the healthcare-associated environment. These findings highlight the significance of bacterial metabolism in modulating the host immune system, thereby facilitating S. aureus survival and persistence.

Oxidative Stress in Benign Prostatic Hyperplasia: Mechanisms, Clinical Relevance and Therapeutic Perspectives

BACKGROUND/OBJECTIVES

Benign prostatic hyperplasia (BPH) is among the most common conditions affecting men as they age, resulting in lower urinary tract symptoms (LUTS) that can profoundly impact quality of life. While historically attributed primarily to androgenic imbalances, current evidence implicates additional factors-particularly oxidative stress (OS) and chronic inflammation-in BPH pathogenesis. This review aims to synthesize research on the interplay between OS, inflammation, and hormonal regulation in BPH, emphasizing their clinical relevance and potential therapeutic implications.

METHODS

A comprehensive review of peer-reviewed literature was conducted focusing on mechanistic studies, clinical trials, and observational reports. Searches included data on ROS generation, antioxidant capacity, inflammatory mediators, and their contribution to pathological prostatic overgrowth. Potential interventions targeting OS-such as antioxidant supplementation, anti-inflammatory drugs, vitamin D receptor agonists, and phytotherapeutics-were also evaluated for their efficacy and safety profiles.

RESULTS

Chronic inflammation and OS were consistently identified within hyperplastic prostate tissue. Excessive ROS production, diminished antioxidant defense, and sustained cytokine release create a proproliferative and antiapoptotic environment, accelerating disease progression. Metabolic comorbidities (e.g., obesity, insulin resistance) further exacerbate these imbalances. Standard therapies (α-blockers and 5-ARIs) effectively relieve symptoms but do not directly address the oxidative-inflammatory axis. Emerging evidence suggests that pharmacological and dietary approaches targeting OS and inflammation may reduce prostate volume expansion and alleviate LUTS.

CONCLUSIONS

Findings indicate that OS and inflammation are key contributors to BPH progression. Incorporating antioxidant and anti-inflammatory strategies alongside conventional treatments holds promise for improving clinical outcomes and patient quality of life. Future research should focus on validating OS-specific biomarkers and optimizing personalized therapy regimens.

Molecular characterization of CIRBP from Takifugu fasciatus and its potential roles in cold-induced liver damage

As a potent stressor, environmental cold stress induces severe mitochondrial dysfunction with the overproduction of reactive oxygen species (ROS) in fish, resulting in liver damage. However, the molecular mechanisms underlying the cold-induced liver damage remain unclear. In the present study, the cold-inducible RNA-binding protein (CIRBP) from Takifugu fasciatus was characterized, and its role in cold-induced oxidative stress damage was investigated. An acute liver injury model was constructed by exposing T. fasciatus individuals to temperatures of 25, 19, and 13 °C. Cold exposure markedly induced histomorphological liver injury and triggered endogenous apoptosis and NLRP3 inflammatory response. Cold treatment significantly increased CIRBP gene expression. A similar expression pattern was detected for thioredoxin (TRX), suggesting that these two proteins play a role in the establishment of cold adaptation. CIRBP binds directly to the 3'-UTR of TRX. Furthermore, in vivo experiment showed that, when CIRBP expression in T. fasciatus is knocked down, the time to loss equilibrium significantly shortened at 13 °C. Taken together, our study revealed that CIRBP is a critical protective factor against cold induced liver damage and that the CIRBP/TRX pathway could function as an underlying mechanism for cold adaptation in teleosts.

Rosmarinic acid alleviates fungal keratitis caused by Aspergillus fumigatus by inducing macrophage autophagy

Fungal keratitis (FK) is an infectious keratopathy can cause serious damage to vision. Its severity is related to the virulence of fungus and response of inflammatory. Rosmarinic acid (RA) extracted from Rosmarinus officinalis exhibits antioxidant, anti-inflammatory and anti-viral properties. The aim of this study was to investigate the effect of RA on macrophage autophagy and its therapeutic effect on FK. In this study, we demonstrated that RA reduced expression of proinflammatory cytokine, lessened the recruitment of inflammatory cells in FK. The relative contents of autophagy markers, such as LC3 and Beclin-1, were significantly up-regulated in RAW 264.7 cells and FK. In addition, RA restored mitochondrial membrane potential (MMP) of macrophage to normal level. RA not only reduced the production of intracellular reactive oxygen species (ROS) but also mitochondria ROS (mtROS) in macrophage. At the same time, RA induced macrophage to M2 phenotype and down-regulated the mRNA expression of IL-6, IL-1β, TNF-α. All the above effects could be offset by the autophagy inhibitor 3-Methyladenine (3-MA). Besides, RA promote phagocytosis of RAW 264.7 cells and inhibits spore germination, biofilm formation and conidial adherence, suggesting a potential therapeutic role for RA in FK.

The involvement of ROS-regulated programmed cell death in hepatocellular carcinoma

Reactive oxidative species (ROS) is a crucial factor in the regulation of cellular biological activity and function, and aberrant levels of ROS can contribute to the development of a variety of diseases, particularly cancer. Numerous discoveries have affirmed that this process is strongly associated with "programmed cell death (PCD)," which refers to the suicide protection mechanism initiated by cells in response to external stimuli, such as apoptosis, autophagy, ferroptosis, etc. Research has demonstrated that ROS-induced PCD is crucial for the development of hepatocellular carcinoma (HCC). These activities serve a dual function in both facilitating and inhibiting cancer, suggesting the existence of a delicate balance within healthy cells that can be disrupted by the abnormal generation of reactive oxygen species (ROS), thereby influencing the eventual advancement or regression of a tumor. In this review, we summarize how ROS regulates PCD to influence the tumorigenesis and progression of HCC. Studying how ROS-induced PCD affects the progression of HCC at a molecular level can help develop better prevention and treatment methods and facilitate the design of more effective preventative and therapeutic strategies.

Dihydroartemisinin, a potential PTGS1 inhibitor, potentiated cisplatin-induced cell death in non-small cell lung cancer through activating ROS-mediated multiple signaling pathways

Dihydroartemisinin (DHA) exerts an anti-tumor effect in multiple cancers, however, the molecular mechanism of DHA and whether DHA facilitates the anti-tumor efficacy of cisplatin in non-small cell lung cancer (NSCLC) are unclear. Here, we found that DHA potentiated the anti-tumor effects of cisplatin in NSCLC cells by stimulating reactive oxygen species (ROS)-mediated endoplasmic reticulum (ER) stress, C-Jun-amino-terminal kinase (JNK) and p38 MAPK signaling pathways both in vitro and in vivo. Of note, we demonstrated for the first time that DHA inhibits prostaglandin G/H synthase 1 (PTGS1) expression, resulting in enhanced ROS production. Importantly, silencing PTGS1 sensitized DHA-induced cell death by increasing ROS production and activating ER-stress, JNK and p38 MAPK signaling pathways. In summary, our findings provided new experimental basis and therapeutic prospect for the combined therapy with DHA and cisplatin in some NSCLC patients.

Targeting endothelial cells with golden spice curcumin: A promising therapy for cardiometabolic multimorbidity

Cardiometabolic multimorbidity (CMM) is an increasingly significant global public health concern. It encompasses the coexistence of multiple cardiometabolic diseases, including hypertension, stroke, heart disease, atherosclerosis, and T2DM. A crucial component to the development of CMM is the disruption of endothelial homeostasis. Therefore, therapies targeting endothelial cells through multi-targeted and multi-pathway approaches hold promise for preventing and treatment of CMM. Curcumin, a widely used dietary supplement derived from the golden spice Carcuma longa, has demonstrated remarkable potential in treatment of CMM through its interaction with endothelial cells. Numerous studies have identified various molecular targets of curcumin (such as NF-κB/PI3K/AKT, MAPK/NF-κB/IL-1β, HO-1, NOs, VEGF, ICAM-1 and ROS). These findings highlight the efficacy of curcumin as a therapeutic agent against CMM through the regulation of endothelial function. It is worth noting that there is a close relationship between the progression of CMM and endothelial damage, characterized by oxidative stress, inflammation, abnormal NO bioavailability and cell adhesion. This paper provides a comprehensive review of curcumin, including its availability, pharmacokinetics, pharmaceutics, and therapeutic application in treatment of CMM, as well as the challenges and future prospects for its clinical translation. In summary, curcumin shows promise as a potential treatment option for CMM, particularly due to its ability to target endothelial cells. It represents a novel and natural lead compound that may offer significant therapeutic benefits in the management of CMM.

Acetyl-L-carnitine attenuates chronic ethanol-induced oxidative stress, ER stress and apoptosis in rat gastric tissue

Consuming alcohol affects almost all organs. Acetaldehyde, formed as the main product as a result of alcohol metabolism, causes the production of free superoxide radicals when oxidized, and accordingly oxidative and apoptotic processes are triggered. There are studies showing that carnitine has effects on oxidative and apoptotic processes that occur in various conditions. However, the mechanisms showing the effects of L-carnitine on these effects of alcohol have not been fully elucidated. In our study, the effects of acetyl-L-carnitine administration on the molecular mechanisms of oxidative stress, endoplasmic reticulum stress, and apoptotic parameters in gastric tissue of rats chronically exposed to alcohol were investigated. Hematoxylin-eosin staining was used for histopathological studies. Endoplasmic reticulum stress markers were detected with immunohistochemical staining and western blotting. Apoptotic index was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. Total oxidant and antioxidant status were examined by ELISA. Our results showed that chronic alcohol administration caused a significant increase in TOS levels, an indicator of oxidative stress, the levels of ER-stress-associated proteins XBP1, GRP78, and CHOP, and % apoptotic index values in rat gastric tissues. Additionally, it was determined that acetyl-L-carnitine administration caused an improvement in those values. Based on our data, we can conclude that acetyl-L-carnitine has a tissue protective effect by scavenging free oxygen radicals and reducing ER stress-related proteins XBP1, GRP78, and CHOP and apoptosis in chronic ethanol-administered rats, and that this natural antioxidant may be beneficial in the treatment of oxidative stress-induced diseases.

Multi-omic analysis reveals metabolic pathways that characterize right-sided colon cancer liver metastasis

There are well demonstrated differences in tumor cell metabolism between right sided (RCC) and left sided (LCC) colon cancer, which could underlie the robust differences observed in their clinical behavior, particularly in metastatic disease. As such, we utilized liquid chromatography-mass spectrometry to perform an untargeted metabolomics analysis comparing frozen liver metastasis (LM) biobank samples derived from patients with RCC (N = 32) and LCC (N = 58) to further elucidate the unique biology of each. We also performed an untargeted RNA-seq and subsequent network analysis on samples derived from an overlapping subset of patients (RCC: N = 10; LCC: N = 18). Our biobank redemonstrates the inferior survival of patients with RCC-derived LM (P = 0.04), a well-established finding. Our metabolomic results demonstrate increased reactive oxygen species associated metabolites and bile acids in RCC. Conversely, carnitines, indicators of fatty acid oxidation, are relatively increased in LCC. The transcriptomic analysis implicates increased MEK-ERK, PI3K-AKT and Transcription Growth Factor Beta signaling in RCC LM. Our multi-omic analysis reveals several key differences in cellular physiology which taken together may be relevant to clinical differences in tumor behavior between RCC and LCC liver metastasis.

Suramin enhances chondrogenic properties by regulating the p67phox/PI3K/AKT/SOX9 signalling pathway

Aims

Autologous chondrocyte implantation (ACI) is a promising treatment for articular cartilage degeneration and injury; however, it requires a large number of human hyaline chondrocytes, which often undergo dedifferentiation during in vitro expansion. This study aimed to investigate the effect of suramin on chondrocyte differentiation and its underlying mechanism.

Methods

Porcine chondrocytes were treated with vehicle or various doses of suramin. The expression of collagen, type II, alpha 1 (COL2A1), aggrecan (ACAN); COL1A1; COL10A1; SRY-box transcription factor 9 (SOX9); nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX); interleukin (IL)-1β; tumour necrosis factor alpha (TNFα); IL-8; and matrix metallopeptidase 13 (MMP-13) in chondrocytes at both messenger RNA (mRNA) and protein levels was determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and western blot. In addition, the supplementation of suramin to redifferentiation medium for the culture of expanded chondrocytes in 3D pellets was evaluated. Glycosaminoglycan (GAG) and collagen production were evaluated by biochemical analyses and immunofluorescence, as well as by immunohistochemistry. The expression of reactive oxygen species (ROS) and NOX activity were assessed by luciferase reporter gene assay, immunofluorescence analysis, and flow cytometry. Mutagenesis analysis, Alcian blue staining, reverse transcriptase polymerase chain reaction (RT-PCR), and western blot assay were used to determine whether p67^phox was involved in suramin-enhanced chondrocyte phenotype maintenance.

Results

Suramin enhanced the COL2A1 and ACAN expression and lowered COL1A1 synthesis. Also, in 3D pellet culture GAG and COL2A1 production was significantly higher in pellets consisting of chondrocytes expanded with suramin compared to controls. Surprisingly, suramin also increased ROS generation, which is largely caused by enhanced NOX (p67^phox) activity and membrane translocation. Overexpression of p67^phox but not p67^phoxAD (deleting amino acid (a.a) 199 to 212) mutant, which does not support ROS production in chondrocytes, significantly enhanced chondrocyte phenotype maintenance, SOX9 expression, and AKT (S473) phosphorylation. Knockdown of p67^phox with its specific short hairpin (sh) RNA (shRNA) abolished the suramin-induced effects. Moreover, when these cells were treated with the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) inhibitor LY294002 or shRNA of AKT1, p67^phox-induced COL2A1 and ACAN expression was significantly inhibited.

Conclusion

Suramin could redifferentiate dedifferentiated chondrocytes dependent on p67^phox activation, which is mediated by the PI3K/AKT/SOX9 signalling pathway.

Cite this article: Bone Joint Res 2022;11(10):723–738.

Dihydroartemisinin enhances the anti-tumor activity of oxaliplatin in colorectal cancer cells by altering PRDX2-reactive oxygen species-mediated multiple signaling pathways

BACKGROUND

Globally, colorectal cancer (CRC) is one of the leading causes of cancer-related deaths. Oxaliplatin based treatments are frequently used as chemotherapeutic methods for CRC, however, associated side effects and drug resistance often limit their clinical application. Dihydroartemisinin (DHA) induces apoptosis in various cancer cells by increasing reactive oxygen species (ROS) production. However, the direct target of DHA and underlying molecular mechanisms in oxaliplatin-mediated anti-tumor activities against CRC are unclear.

METHODS

We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), flow cytometry, and colony formation assays to investigate cell phenotype alterations and ROS generation. We also used quantitative Real-Time PCR (qRT-PCR) and western blotting to measure relative gene and protein expression. Finally, an in vivo mouse xenograft model was used to assess the anti-tumor activity of oxaliplatin and DHA alone, and combinations.

RESULTS

DHA synergistically enhanced the anti-tumor activity of oxaliplatin in colon cancer cells by regulating ROS-mediated ER stress, signal transducer and activator of transcription 3 (STAT3), C-Jun-amino-terminal kinase (JNK), and p38 signaling pathways. Mechanistically, DHA increased ROS levels by inhibiting peroxiredoxin 2 (PRDX2) expression, and PRDX2 knockdown sensitized DHA-mediated cell growth inhibition and ROS production in CRC cells. A mouse xenograft model showed strong anti-tumor effects from combination treatments when compared with single agents.

CONCLUSIONS

We demonstrated an improved therapeutic strategy for CRC patients by combining DHA and oxaliplatin treatments.

Pituitary Adenylate Cyclase-Activating Polypeptide Protects Corneal Epithelial Cells against UV-B-Induced Apoptosis via ROS/JNK Pathway Inhibition

PACAP is widely expressed throughout the body. It exerts a beneficial role in the eye, including the cornea. The corneal epithelium is regularly exposed to diverse types of insults, including ultraviolet B (UV-B) radiation. Previously, we showed the protective role played by PACAP in counteracting UV-B ray insults in human corneal endothelial cells; however, its involvement in corneal epithelium protection against ROS induced by UV-B radiation, and the underlying mechanisms, remain to be determined. Here, we demonstrated that the peptide treatment reduced UV-B-induced ROS generation by playing an anti-apoptotic role via JNK-signaling pathway inhibition. Overall, our results can provide guidance in the therapeutic use of PACAP for the treatment of epithelial corneal damage.

Corilagin exhibits differential anticancer effects through the modulation of STAT3/5 and MAPKs in human gastric cancer cells

Corilagin (CLG) is a hydrolyzable tannin and possesses various pharmacological activities. Here, we investigated the impact of CLG as an anti-tumor agent against human gastric tumor cells. We observed that CLG could cause negative regulation of JAKs-Src-STAT3/5 signaling axis in SNU-1 cells, but did not affect these pathways in SNU-16 cells. Interestingly, CLG promoted the induction of mitogen-activated protein kinases (MAPKs) signaling pathways in only SNU-16 cells, but not in the SNU-1 cells. CLG exhibited apoptotic effects that caused an increased accumulation of the cells in sub-G1 phase and caspase-3 activation in both SNU-1 and SNU-16 cell lines. We also noticed that CLG and docetaxel co-treatment could exhibit significantly enhanced apoptotic effects against SNU-1 cells. Moreover, the combinations treatment of CLG and docetaxel markedly inhibited cell growth, phosphorylation of JAK-Src-STAT3 and induced substantial apoptosis. Additionally, pharmacological inhibition of JNK, p38, and ERK substantially blocked CLG-induced activation of MAPKs, cell viability, and apoptosis, thereby implicating the pivotal role of MAPKs in the observed anti-cancer effects of CLG. Taken together, our data suggest that CLG could effectively block constitutive STAT3/5 activation in SNU-1 cells but induce sustained MAPKs activation in SNU-16 cells.

Activity-Dependent Neuroprotective Protein (ADNP)-Derived Peptide (NAP) Counteracts UV-B Radiation-Induced ROS Formation in Corneal Epithelium

The corneal epithelium, the outermost layer of the cornea, acts as a dynamic barrier preventing access to harmful agents into the intraocular space. It is subjected daily to different insults, and ultraviolet B (UV-B) irradiation represents one of the main causes of injury. In our previous study, we demonstrated the beneficial effects of pituitary adenylate cyclase-activating polypeptide (PACAP) against UV-B radiation damage in the human corneal endothelium. Some of its effects are mediated through the activation of the intracellular factor, known as the activity-dependent protein (ADNP). In the present paper, we have investigated the role of ADNP and the small peptide derived from ADNP, known as NAP, in the corneal epithelium. Here, we have demonstrated, for the first time, ADNP expression in human and rabbit corneal epithelium as well as its protective effect by treating the corneal epithelial cells exposed to UV-B radiations with NAP. Our results showed that NAP treatment prevents ROS formation by reducing UV-B-irradiation-induced apoptotic cell death and JNK signalling pathway activation. Further investigations are needed to deeply investigate the possible therapeutic use of NAP to counteract corneal UV-B damage.

Research Progress on Fumonisin B1 Contamination and Toxicity: A Review

Fumonisin B1 (FB1), belonging to the member of fumonisins, is one of the most toxic mycotoxins produced mainly by Fusarium proliferatum and Fusarium verticillioide. FB1 has caused extensive contamination worldwide, mainly in corn, rice, wheat, and their products, while it also poses a health risk and is toxic to animals and human. It has been shown to cause oxidative stress, endoplasmic reticulum stress, cellular autophagy, and apoptosis. This review focuses on the current stage of FB1 contamination, its toxic effects of acute toxicity, immunotoxicity, organ toxicity, and reproductive toxicity on animals and humans. The potential toxic mechanisms of FB1 are discussed. One of the main aims of the work is to provide a reliable reference strategy for understanding the occurrence and toxicity of FB1.

Extracellular Vesicles under Oxidative Stress Conditions: Biological Properties and Physiological Roles

Under physio-pathological conditions, cells release membrane-surrounded structures named Extracellular Vesicles (EVs), which convey their molecular cargo to neighboring or distant cells influencing their metabolism. Besides their involvement in the intercellular communication, EVs might represent a tool used by cells to eliminate unnecessary/toxic material. Here, we revised the literature exploring the link between EVs and redox biology. The first proof of this link derives from evidence demonstrating that EVs from healthy cells protect target cells from oxidative insults through the transfer of antioxidants. Oxidative stress conditions influence the release and the molecular cargo of EVs that, in turn, modulate the redox status of target cells. Oxidative stress-related EVs exert both beneficial or harmful effects, as they can carry antioxidants or ROS-generating enzymes and oxidized molecules. As mediators of cell-to-cell communication, EVs are also implicated in the pathophysiology of oxidative stress-related diseases. The review found evidence that numerous studies speculated on the role of EVs in redox signaling and oxidative stress-related pathologies, but few of them unraveled molecular mechanisms behind this complex link. Thus, the purpose of this review is to report and discuss this evidence, highlighting that the analysis of the molecular content of oxidative stress-released EVs (reminiscent of the redox status of originating cells), is a starting point for the use of EVs as diagnostic and therapeutic tools in oxidative stress-related diseases.

Revealing the Modular Similarities and Differences Among Alzheimer's Disease, Vascular Dementia, and Parkinson's Disease in Genomic Networks

Alzheimer's disease (AD), vascular dementia (VD), and Parkinson's disease (PD) exert increasingly lethal or disabling effects on humans, but the associations among these diseases at the molecular level remain unclear. In our research, lists of genes related to these three diseases were acquired from public databases. We constructed gene-gene networks of the lists of disease-related genes using the STRING database and selected the plug-in MCODE as the most suitable method to divide the three disease-associated networks into modules through an entropy calculation. Notably, 1173 AD-related, 203 VD-related, and 722 PD-related genes as well as 72 overlapping genes were observed among the three diseases. By dividing the modules from the gene network, we divided the AD-related gene network into 27 modules, the VD-related gene network into 8 modules, and the PD-related gene network into 17 modules. After the enrichment analysis of each disease-related gene, 146 overlapping biological processes and 32 overlapping pathways were identified. Ultimately, through similarity analysis of the genes, biological processes, and pathways, we found that AD and VD were the most closely related at the biological process and pathway levels, with similarity coefficients of 0.2784 and 0.3626, respectively. After analyzing the overlapping gene network, we found that INS might play an important role in the network and that insulin and its signaling pathways may play a key role in these neurodegenerative diseases. Our research illustrates a new method for in-depth research on the three diseases, which may accelerate the progress of developing new therapeutics and may be applied to prevent neurodegenerative diseases.

Alleviation of acute pancreatitis-associated lung injury by inhibiting the p38 mitogen-activated protein kinase pathway in pulmonary microvascular endothelial cells

BACKGROUND

Previous reports have suggested that the p38 mitogen-activated protein kinase signaling pathway is involved in the development of severe acute pancreatitis (SAP)-related acute lung injury (ALI). Inhibition of p38 by SB203580 blocked the inflammatory responses in SAP-ALI. However, the precise mechanism associated with p38 is unclear, particularly in pulmonary microvascular endothelial cell (PMVEC) injury.

AIM

To determine its role in the tumor necrosis factor-alpha (TNF-α)-induced inflammation and apoptosis of PMVECs in vitro. We then conducted in vivo experiments to confirm the effect of SB203580-mediated p38 inhibition on SAP-ALI.

METHODS

In vitro, PMVEC were transfected with mitogen-activated protein kinase kinase 6 (Glu), which constitutively activates p38, and then stimulated with TNF-α. Flow cytometry and western blotting were performed to detect the cell apoptosis and inflammatory cytokine levels, respectively. In vivo, SAP-ALI was induced by 5% sodium taurocholate and three different doses of SB203580 (2.5, 5.0 or 10.0 mg/kg) were intraperitoneally injected prior to SAP induction. SAP-ALI was assessed by performing pulmonary histopathology assays, measuring myeloperoxidase activity, conducting arterial blood gas analyses and measuring TNF-α, interleukin (IL)-1β and IL-6 levels. Lung microvascular permeability was measured by determining bronchoalveolar lavage fluid protein concentration, Evans blue extravasation and ultrastructural changes in PMVECs. The apoptotic death of pulmonary cells was confirmed by performing a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling analysis and examining the Bcl2, Bax, Bim and cle-caspase3 levels. The proteins levels of P-p38, NFκB, IκB, P-signal transducer and activator of transcription-3, nuclear factor erythroid 2-related factor 2, HO-1 and Myd88 were detected in the lungs to further evaluate the potential mechanism underlying the protective effect of SB203580.

RESULTS

In vitro, mitogen-activated protein kinase (Glu) transfection resulted in higher apoptotic rates and cytokine (IL-1β and IL-6) levels in TNF-α-treated PMVECs. In vivo, SB2035080 attenuated lung histopathological injury, decreased inflammatory activity (TNF-α, IL-1β, IL-6 and myeloperoxidase) and preserved pulmonary function. Furthermore, SB203580 significantly reversed changes in the bronchoalveolar lavage fluid protein concentration, Evans blue accumulation, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cell numbers, apoptosis-related proteins (cle-caspase3, Bim and Bax) and endothelial microstructure. Moreover, SB203580 significantly reduced the pulmonary P-p38, NFκB, P-signal transducer and activator of transcription-3 and Myd88 levels but increased the IκB and HO-1 levels.

CONCLUSION

p38 inhibition may protect against SAP-ALI by alleviating inflammation and the apoptotic death of PMVECs.

Korean traditional herbal formula Soshiho-tang attenuates memory impairment and neuronal damage in mice with amyloid-beta-induced Alzheimer's disease

Background

Soshiho-tang (SST), also known as Xiaochaihu-tang in China and Sho-saiko-to in Japan, is an Oriental herbal formula traditionally used to treat febrile diseases. Recently, several in vitro and in vivo studies have reported the anti-cancer, anti-liver disease, and anti-inflammatory activities of SST. However, there is little evidence of its effects on neurological diseases. We previously reported the inhibitory effects of SST on in vitro acetylcholinesterase (AChE) activation and amyloid-β (Aβ) aggregation, which are crucial hallmarks of Alzheimer's disease (AD). In the present study, we report that SST has preventive effects on memory impairment and neuronal cell changes in an Aβ-induced AD-like mouse model.

Methods

Male mice underwent injection of Aβ aggregates and administered SST (500, 1,000, or 2,000 mg/kg/day) for 20 days. Behavioral tests (passive avoidance task [PAT] and Morris water maze [MWM] test) were conducted. Lastly, brain sections were obtained from sacrificed mice for quantitative analysis.

Results

Intracerebroventricular (ICV) injection of Aβ aggregates significantly decreased the latency time in the PAT and MWM test compared to normal control. In contrast, SST administration markedly reversed the latency caused by Aβ injection. Additionally, our data revealed that SST-mediated improvements in memory impairment are related to its neuroprotective and anti-neuroinflammatory effects. On histological analysis, SST treatment protected neuronal loss and damage as well as microglial activation, and ameliorated amount of Aβ in brain of mouse model of AD.

Conclusion

Our findings suggest that SST may be a promising candidate for the development of novel drugs for AD.

The impact of reactive oxygen species in the development of cardiometabolic disorders: a review

Oxidative stress, an alteration in the balance between reactive oxygen species (ROS) generation and antioxidant buffering capacity, has been implicated in the pathogenesis of cardiometabolic disorders (CMD). At physiological levels, ROS functions as signalling mediators, regulates various physiological functions such as the growth, proliferation, and migration endothelial cells (EC) and smooth muscle cells (SMC); formation and development of new blood vessels; EC and SMC regulated death; vascular tone; host defence; and genomic stability. However, at excessive levels, it causes a deviation in the redox state, mediates the development of CMD. Multiple mechanisms account for the rise in the production of free radicals in the heart. These include mitochondrial dysfunction and uncoupling, increased fatty acid oxidation, exaggerated activity of nicotinamide adenine dinucleotide phosphate oxidase (NOX), reduced antioxidant capacity, and cardiac metabolic memory. The purpose of this study is to discuss the link between oxidative stress and the aetiopathogenesis of CMD and highlight associated mechanisms. Oxidative stress plays a vital role in the development of obesity and dyslipidaemia, insulin resistance and diabetes, hypertension via various mechanisms associated with ROS-led inflammatory response and endothelial dysfunction.

The Role of Reactive Oxygen Species in the Life Cycle of the Mitochondrion

Currently, it is known that, in living systems, free radicals and other reactive oxygen and nitrogen species play a double role, because they can cause oxidative damage and tissue dysfunction and serve as molecular signals activating stress responses that are beneficial to the organism. It is also known that mitochondria, because of their capacity to produce free radicals, play a major role in tissue oxidative damage and dysfunction and provide protection against excessive tissue dysfunction through several mechanisms, including the stimulation of permeability transition pore opening. This process leads to mitoptosis and mitophagy, two sequential processes that are a universal route of elimination of dysfunctional mitochondria and is essential to protect cells from the harm due to mitochondrial disordered metabolism. To date, there is significant evidence not only that the above processes are induced by enhanced reactive oxygen species (ROS) production, but also that such production is involved in the other phases of the mitochondrial life cycle. Accumulating evidence also suggests that these effects are mediated through the regulation of the expression and the activity of proteins that are engaged in processes such as genesis, fission, fusion, and removal of mitochondria. This review provides an account of the developments of the knowledge on the dynamics of the mitochondrial population, examining the mechanisms governing their genesis, life, and death, and elucidating the role played by free radicals in such processes.

Protective role of curcumin against lipopolysaccharide-induced inflammation and apoptosis in human neutrophil

Background

Sepsis, an uncontrolled host response to infection, may be life-threatening organ injury. Neutrophils play a critical role in regulation of host immune response to infection. Curcumin, known as a spice and food coloring agent, possesses anti-inflammatory properties. In this study, we investigated the effects of curcumin on lipopolysaccharide (LPS)-induced neutrophil activation with its signaling pathways.

Methods

Isolated human neutrophils were incubated without or with LPS and curcumin, and the expression of pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and IL-8 were assessed by enzyme-linked immunosorbent assays. The expression of mitogen-activated protein kinases such as p38, extracellularsignal-regulated kinase (ERK)1/2, and c-Jun N-terminal kinase (JNK) were evaluated by Western blot analysis. Neutrophil apoptosis was also measured by fluorescence-activated cell sorting (annexin V/propidium iodide) in LPS-stimulated neutrophils under treatment with curcumin.

Results

Curcumin attenuated expression of TNF-α, IL-6, and IL-8 and the phosphorylation levels of p38 and JNK, but not ERK1/2, in LPS-stimulated neutrophils. Additionally, curcumin restored the delayed neutrophil apoptosis by LPS-stimulated neutrophils(19.7 ± 3.2 to 38.2 ± 0.5%, P < 0.05).

Conclusions

Our results reveal the underlying mechanism of how curcumin attenuate neutrophil activation and suggest potential clinic applications of curcumin supplementation for patients with severe sepsis and septic shock. Additional clinical studies are required to confirm these in vitro findings.

Medicinal Profile, Phytochemistry, and Pharmacological Activities of Murraya koenigii and its Primary Bioactive Compounds

The discovery of several revitalizing molecules that can stop or reduce the pathology of a wide range of diseases will be considered a major breakthrough of the present time. Available synthetic compounds may provoke side effects and health issues, which heightens the need for molecules from plants and other natural resources under discovery as potential methods of replacing synthetic compounds. In traditional medicinal therapies, several plant extracts and phytochemicals have been reported to impart remedial effects as better alternatives. Murraya koenigii (M. koenigii) belongs to the Rutaceae family, which is commonly used as a medicinally important herb of Indian origin in the Ayurvedic system of medicine. Previous reports have demonstrated that the leaves, roots, and bark of this plant are rich sources of carbazole alkaloids, which produce potent biological activities and pharmacological effects. These include antioxidant, antidiabetic, anti-inflammatory, antitumor, and neuroprotective activities. The present review provides insight into the major components of M. koenigii and their pharmacological activities against different pathological conditions. The review also emphasizes the need for more research on the molecular basis of such activity in various cellular and animal models to validate the efficacy of M. koenigii and its derivatives as potent therapeutic agents.

Echinocandin Resistance in Aspergillus fumigatus Has Broad Implications for Membrane Lipid Perturbations That Influence Drug-Target Interactions

Echinocandin drugs target the fungal enzyme β-(1,3)-glucan synthase (GS), which is required for the synthesis of cell wall component β-(1,3)-d-glucan. They are first-line therapy for Candida infections but are increasingly used as second-line therapy for Aspergillus infections. Resistance to echinocandins has been mainly studied in Candida and occurs due to mutations in FKS genes encoding GS. In our recent report, we identified a novel mechanism of echinocandin resistance in Aspergillus fumigatus. We showed that caspofungin exposure modifies GS, rendering it insensitive to echinocandins. This mechanism of resistance involved alteration of the GS lipid microenvironment and was mediated via an off-target effect on mitochondria leading to increased reactive oxygen species (ROS). We hypothesized that caspofungin-induced ROS alters the lipid composition around GS, changing its conformation and making it insensitive to echinocandins. In this commentary, we review both fks1-dependent and fks1-independent mechanisms of echinocandin resistance in A fumigatus. We believe this new resistance mechanism is also conserved among Candida spp. with implications for drug tolerance and/or resistance. Furthermore, we propose that ROS acts as a signaling molecule regulating lipid biogenesis, which impacts the structure-function of membrane proteins with implications for other types of drug-target interactions.

The Role of Signaling Pathways of Inflammation and Oxidative Stress in Development of Senescence and Aging Phenotypes in Cardiovascular Disease

The ASK1-signalosome→p38 MAPK and SAPK/JNK signaling networks promote senescence (in vitro) and aging (in vivo, animal models and human cohorts) in response to oxidative stress and inflammation. These networks contribute to the promotion of age-associated cardiovascular diseases of oxidative stress and inflammation. Furthermore, their inhibition delays the onset of these cardiovascular diseases as well as senescence and aging. In this review we focus on whether the (a) ASK1-signalosome, a major center of distribution of reactive oxygen species (ROS)-mediated stress signals, plays a role in the promotion of cardiovascular diseases of oxidative stress and inflammation; (b) The ASK1-signalosome links ROS signals generated by dysfunctional mitochondrial electron transport chain complexes to the p38 MAPK stress response pathway; (c) the pathway contributes to the sensitivity and vulnerability of aged tissues to diseases of oxidative stress; and (d) the importance of inhibitors of these pathways to the development of cardioprotection and pharmaceutical interventions. We propose that the ASK1-signalosome regulates the progression of cardiovascular diseases. The resultant attenuation of the physiological characteristics of cardiomyopathies and aging by inhibition of the ASK1-signalosome network lends support to this conclusion. Importantly the ROS-mediated activation of the ASK1-signalosome p38 MAPK pathway suggests it is a major center of dissemination of the ROS signals that promote senescence, aging and cardiovascular diseases. Pharmacological intervention is, therefore, feasible through the continued identification of potent, non-toxic small molecule inhibitors of either ASK1 or p38 MAPK activity. This is a fruitful future approach to the attenuation of physiological aspects of mammalian cardiomyopathies and aging.

Resistance Training, Antioxidant Status, and Antioxidant Supplementation

Resistance training is known to promote the generation of reactive oxygen species. Although this can likely upregulate the natural, endogenous antioxidant defense systems, high amounts of reactive oxygen species can cause skeletal muscle damage, fatigue, and impair recovery. To prevent these, antioxidant supplements are commonly consumed along with exercise. Recently, it has been shown that these reactive oxygen species are important for the cellular adaptation process, acting as redox signaling molecules. However, most of the research regarding antioxidant status and antioxidant supplementation with exercise has focused on endurance training. In this review, the authors discuss the evidence for resistance training modulating the antioxidant status. They also highlight the effects of combining antioxidant supplementation with resistance training on training-induced skeletal muscle adaptations.

Particulate Matter Exposure History Affects Antioxidant Defense Response of Mouse Lung to Haze Episodes

Few studies have focused on the association between previous particulate matter (PM) exposure and antioxidant defense response to a haze challenge. In this study, a combined exposure model was used to investigate whether and how PM exposure history affected the antioxidant defense response to haze episodes. At first, C57BL/6 male mice were randomly assigned to three groups and exposed for 5 weeks to whole ambient air, ambient air containing a low (≤75 μg/m³) PM concentration, and filtered air, which simulated different exposure history of high, relatively low, and almost zero PM concentrations. Thereafter, all mice underwent a 3-day haze exposure followed by a 7-day exposure to filtered air. The indexes involved in the primary and secondary antioxidant defense response were determined after pre-exposure and haze exposure, as well as 1 day, 3 days, and 7 days after haze exposure. Our research demonstrated repeated exposure to a high PM concentration compromised the antioxidant defense response and was accompanied by an increased susceptibility to a haze challenge. Conversely, mice with a lower PM exposure developed an oxidative stress adaption that protected them against haze challenge more efficiently and in a more timely manner than was the case in mice without PM exposure history.

The roles of p38 MAPK → COX2 and NF-κB → COX2 signal pathways in age-related testosterone reduction

In our study, we explored changes in the redox status and inflammatory response in the testes of the SAMP8 model of varying ages (2, 4, 8, 10 months old) compared with control mice SAMR1 by the methods of immunohistochemical staining, Western blotting, RT-PCR and Luminex multi-analyte cytokine profiling. We found that as ROS and inflammation levels increased during aging, steroidogenic enzymes (StAR and P450scc) reduced and led to the decline of testosterone production eventually. The pathways of P38 MAPK → COX2 and NF-κB → COX2 were detected by using specific inhibitors of SB203580 and Bay 11-7082 in isolated Leydig cells. These results indicated that activation of both p38 MAPK → COX2 and NF-κB → COX2 signaling pathways are functionally linked to the oxidative stress response and chronic inflammation during aging, and mediate their inhibitory effects on testosterone production.

Mediators of Physical Activity Protection against ROS-Linked Skeletal Muscle Damage

Unaccustomed and/or exhaustive exercise generates excessive free radicals and reactive oxygen and nitrogen species leading to muscle oxidative stress-related damage and impaired contractility. Conversely, a moderate level of free radicals induces the body's adaptive responses. Thus, a low oxidant level in resting muscle is essential for normal force production, and the production of oxidants during each session of physical training increases the body's antioxidant defenses. Mitochondria, NADPH oxidases and xanthine oxidases have been identified as sources of free radicals during muscle contraction, but the exact mechanisms underlying exercise-induced harmful or beneficial effects yet remain elusive. However, it is clear that redox signaling influences numerous transcriptional activators, which regulate the expression of genes involved in changes in muscle phenotype. The mitogen-activated protein kinase family is one of the main links between cellular oxidant levels and skeletal muscle adaptation. The family components phosphorylate and modulate the activities of hundreds of substrates, including transcription factors involved in cell response to oxidative stress elicited by exercise in skeletal muscle. To elucidate the complex role of ROS in exercise, here we reviewed the literature dealing on sources of ROS production and concerning the most important redox signaling pathways, including MAPKs that are involved in the responses to acute and chronic exercise in the muscle, particularly those involved in the induction of antioxidant enzymes.

M1 macrophage mediated increased reactive oxygen species (ROS) influence wound healing via the MAPK signaling in vitro and in vivo

Thulium laser resection of the prostate (TmLRP), a major treatment for benign prostatic hyperplasia (BPH), has several postoperative complications that affect the patients' quality of life. The aim of this study was to investigate the effect of the M1 macrophage-secreted reactive oxygen species (ROS) on prostatic wound healing, and the role of MAPK signaling in this process. A co-culture model in vitro was established using macrophages and prostate epithelial or stromal cells. Cell proliferation, migration, apoptosis, MAPK pathway-related gene expression levels were evaluated by standard assays. In addition, an in vivo model of prostatectomy was established in beagles by subjecting them to TmLRP, and were either treated with N-acetyl-L-cysteine (NAC) and or placebo. Wound healing and re-epithelialization were analyzed histopathologically in both groups, in addition to macrophage polarization, oxidative stress levels and MAPK pathway-related proteins expressions. Intracellular ROS levels were significantly increased in the prostate epithelial and stromal cells following co-culture with M1-like macrophages and H₂O₂ exposure via MAPK activation, which affected their proliferation, migration and apoptosis, and delayed the wound healing process. The cellular functions and wound healing capacity of the prostate cells were restored by blocking or clearing the macrophage-secreted ROS. In the beagle model, increased ROS levels impaired cellular functions, and appropriate removing ROS accelerated the wound healing process.

Signaling pathways involved in p38-ERK and inflammatory factors mediated the anti-fibrosis effect of AD-2 on thioacetamide-induced liver injury in mice

Ginseng is a type of medicinal and edible homologous plant that is very common in medicine, food and even cosmetics.

Inhibition of mitochondrial respiration under hypoxia and increased antioxidant activity after reoxygenation of Tribolium castaneum

Regulating the air in low-oxygen environments protects hermetically stored grains from storage pests damage. However, pests that can tolerate hypoxic stress pose a huge challenge in terms of grain storage. We used various biological approaches to determine the fundamental mechanisms of Tribolium castaneum to cope with hypoxia. Our results indicated that limiting the available oxygen to T. castaneum increased glycolysis and inhibited the Krebs cycle, and that accumulated pyruvic acid was preferentially converted to lactic acid via anaerobic metabolism. Mitochondrial aerobic respiration was markedly suppressed for beetles under hypoxia, which also might have led to mitochondrial autophagy. The enzymatic activity of citrate synthase decreased in insects under hypoxia but recovered within 12 h, which suggested that the beetles recovered from the hypoxia. Moreover, hypoxia-reperfusion resulted in severe oxidative damage to insects, and antioxidant levels increased to defend against the high level of reactive oxygen species. In conclusion, our findings show that mitochondria were the main target in T. castaneum in response to low oxygen. The beetles under hypoxia inhibited mitochondrial respiration and increased antioxidant activity after reoxygenation. Our research advances the field of pest control and makes it possible to develop more efficient strategies for hermetic storage.

Lactoferrin inhibits aflatoxin B1- and aflatoxin M1-induced cytotoxicity and DNA damage in Caco-2, HEK, Hep-G2, and SK-N-SH cells

Aflatoxins, including aflatoxin B₁ (AFB₁) and M₁ (AFM₁), are natural potent carcinogens produced by Aspergillus spp. These compounds, which can often be detected in dairy foods, can cause diseases in human beings. However, the molecular mechanisms involved in cytotoxicity, as well as methods for intervention, remain largely unexplored. For example, it is unclear whether lactoferrin (LF), a major antioxidant in milk, can inhibit the cytotoxicity of AFB₁ and AFM₁. In this study, we assessed AFB₁- and AFM₁-induced cell toxicity by measuring cell viability, membrane permeability, and genotoxicity, and then investigated the ability of LF to protect cells against AFB₁ and AFM₁. In Caco-2, HEK, Hep-G2, and SK-N-SH cells, 4 μg/mL AFB₁ or AFM₁ significantly inhibited cell growth, increased the level of lactate dehydrogenase, induced genetic damage, and increased the levels of signal-regulated kinase (ERK1/2) and c-Jun N-terminal kinase (JNK) (p < 0.05). AFB₁ was more genotoxic than AFM₁ in all four cell lines, especially in Hep-G2. In Caco-2, Hep-G2, and SK-N-SH, incubation of AF-treated cells with 1000 μg/mL LF significantly decreased cytotoxicity, oxidation level, DNA damage, and levels of ERK1/2 and JNK (p < 0.05). Our data demonstrate that AFB₁ or AFM₁ induced cytotoxicity and DNA damage in these four cell lines, and that LF alleviated toxicity by decreasing oxidative stress mediated by mitogen-activated protein kinase pathways.

Apoptosis signal-regulating kinase 1 mediates the inhibitory effect of hepatocyte nuclear factor-4α on hepatocellular carcinoma

Previous studies provided substantial evidence of a striking suppressive effect of hepatocyte nuclear factor 4α (HNF4α) on hepatocellular carcinoma (HCC). Apoptosis signal-regulating kinase 1 (ASK1) is involved in death receptor-mediated apoptosis and may acts as a tumor suppressor in hepatocarcinogenesis. However, the status and function of ASK1 during HCC progression are unclear. In this study, we found that HNF4α increased ASK1 expression by directly binding to its promoter. ASK1 expression was dramatically suppressed and correlated with HNF4α levels in HCC tissues. Reduced ASK1 expression was associated with aggressive tumors and poor prognosis for human HCC. Moreover, ASK1 inhibited the malignant phenotype of HCC cells in vitro. Intratumoral ASK1 injection significantly suppressed the growth of subcutaneous HCC xenografts in nude mice. More interestingly, systemic ASK1 delivery strikingly inhibited the growth of orthotopic HCC nodules in NOD/SCID mice. In addition, inhibition of endogenous ASK1 partially reversed the suppressive effects of HNF4α on HCC. Collectively, this study highlights the suppressive effect of ASK1 on HCC and its biological significance in HCC development. These outcomes broaden the knowledge of ASK1 function in HCC progression, and provide a novel potential prognostic biomarker and therapeutic target for advanced HCC.

Physiological roles of ASK family members in innate immunity and their involvement in pathogenesis of immune diseases

Cells are always exposed to various types of stress, including physical, chemical, and biological stresses, and are required to sense immediately and respond appropriately to these stresses. The apoptosis signal-regulating kinase (ASK) family members are stress-responsive kinases, which are activated by not only physicochemical stresses, such as oxidative stress, osmotic pressure, calcium overload, and anti-cancer drugs, but also biological stresses, such as inflammatory cytokines and pathogen infection. Recently, we found that ASK1, a member of ASK family, is activated by bacterial components, such as lipopolysaccharide, in a reactive oxygen species (ROS)-dependent manner, demonstrating that ASK1 is required for the innate immune response and plays a critical role in the regulation of innate immune signaling. Moreover, our findings indicate that ROS are common mediators in physicochemical stress signaling, including redox signaling, and biological stress signaling, including innate immune signaling. This review especially focuses on the roles of ASK family in innate immunity and provides recent progress in our knowledge on activation mechanisms and physiological functions of ASK family kinases in innate immune responses.

Phosphorylation of Icariin Can Alleviate the Oxidative Stress Caused by the Duck Hepatitis Virus A through Mitogen-Activated Protein Kinases Signaling Pathways

The duck virus hepatitis (DVH) caused by the duck hepatitis virus A (DHAV) has produced extensive economic losses to the duck industry. The currently licensed commercial vaccine has shown some defects and does not completely prevent the DVH. Accordingly, a new alternative treatment for this disease is urgently needed. Previous studies have shown that icariin (ICA) and its phosphorylated derivative (pICA) possessed good anti-DHAV effects through direct and indirect antiviral pathways, such as antioxidative stress. But the antioxidant activity showed some differences between ICA and pICA. The aim of this study is to prove that ICA and pICA attenuate oxidative stress caused by DHAV in vitro and in vivo, and to investigate their mechanism of action to explain their differences in antioxidant activities. In vivo, the dynamic deaths, oxidative evaluation indexes and hepatic pathological change scores were detected. When was added the hinokitiol which showed the pro-oxidative effect as an intervention method, pICA still possessed more treatment effect than ICA. The strong correlation between mortality and oxidative stress proves that ICA and pICA alleviate oxidative stress caused by DHAV. This was also demonstrated by the addition of hydrogen peroxide (H2O2) as an intervention method in vitro. pICA can be more effective than ICA to improve duck embryonic hepatocytes (DEHs) viability and reduce the virulence of DHAV. The strong correlation between TCID50 and oxidative stress demonstrates that ICA and pICA can achieve anti-DHAV effects by inhibiting oxidative stress. In addition, the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of ICA and pICA showed significant difference. pICA could significantly inhibit the phosphorylation of p38, extra cellular signal regulated Kinase (ERK 1/2) and c-Jun N-terminal kinase (JNK), which were related to mitogen-activated protein kinases (MAPKs) signaling pathways. Ultimately, compared to ICA, pICA exhibited more antioxidant activity that could regulate oxidative stress-related indicators, and inhibited the phosphorylation of MAPKs signaling pathway.

Fructose-rich diet and insulin action in female rat heart: Estradiol friend or foe?

Increased intake of fructose in humans and laboratory animals is demonstrated to be a risk factor for development of metabolic disorders (insulin resistance, metabolic syndrome, type 2 diabetes) and cardiovascular diseases. On the other hand, estradiol is emphasized as a cardioprotective agent. The main goal of this review is to summarize recent findings on damaging cardiac effects of fructose-rich diet in females, mostly experimental animals, and to evaluate protective capacity of estradiol. Published results of our and other research groups indicate mostly detrimental effects of fructose-rich diet on cardiac insulin signaling molecules, glucose and fatty acid metabolism, nitric oxide production and ion transport, as well as renin-angiotensin system and inflammation. Some of these processes are involved in cardiac insulin signal transmission, others are regulated by insulin or have an influence on insulin action. Administration of estradiol to ovariectomized female rats, exposed to increased intake of fructose, was mostly beneficial to the heart, but sometimes it was ineffective or even detrimental, depending on the particular processes. We believe that these data, carefully translated to human population, could be useful for clinicians dealing with postmenopausal women susceptible to metabolic diseases and hormone replacement therapy.

Andrographolide inhibits hypoxia-induced HIF-1α-driven endothelin 1 secretion by activating Nrf2/HO-1 and promoting the expression of prolyl hydroxylases 2/3 in human endothelial cells

Andrographolide, the main bioactive component of the medicinal plant Andrographis paniculata, has been shown to possess potent anti-inflammatory activity. Endothelin 1 (ET-1), a potent vasoconstrictor peptide produced by vascular endothelial cells, displays proinflammatory property. Hypoxia-inducible factor 1α (HIF-1α), the regulatory member of the transcription factor heterodimer HIF-1α/β, is one of the most important molecules that responds to hypoxia. Changes in cellular HIF-1α protein level are the result of altered gene transcription and protein stability, with the latter being dependent on prolyl hydroxylases (PHDs). In this study, inhibition of pro-inflammatory ET-1 expression and changes of HIF-1α gene transcription and protein stability under hypoxia by andrographolide in EA.hy926 endothelial-like cells were investigated. Hypoxic conditions were created using the hypoxia-mimetic agent CoCl_2. We found that hypoxia stimulated the production of reactive oxygen species (ROS), the expression of HIF-1α mRNA and protein, and the expression and secretion of ET-1. These effects, however, were attenuated by co-exposure to andrographolide, bilirubin, and RuCO. Silencing Nrf2 and heme oxygenase 1 (HO-1) reversed the inhibitory effects of andrographolide on hypxoia-induced HIF-1α mRNA and protein expression. Moreover, andrographolide increased the expression of prolyl hydroxylases (PHD) 2/3, which hydroxylate HIF-1α and promotes HIF-1α proteasome degradation, with an increase in HIF-1α hydroxylation was noted under hypoxia. Inhibition of p38 MAPK abrogated the hypoxia-induced increases in HIF-1α mRNA and protein expression as well as ET-1 mRNA expression and secretion. Taken together, these results suggest that andrographolide suppresses hypoxia-induced pro-inflammatory ET-1 expression by activating Nrf2/HO-1, inhibiting p38 MAPK signaling, and promoting PHD2/3 expression. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 918-930, 2017.

Fluctuation of ROS regulates proliferation and mediates inhibition of migration by reducing the interaction between DLC1 and CAV-1 in breast cancer cells

The aim of our present study was to elucidate the effects of up-regulation and down-regulation of intracellular reactive oxygen species (ROS) level on proliferation, migration, and related molecular mechanism. Breast cancer cells were treated by catalase or H₂O₂. MTT, colony formation assay, and Hoechst/PI staining were used to evaluate proliferation and apoptosis. The level of intracellular ROS was measured by dichlorodihydrofluorescein diacetate probes. The ability of migration was detected by wound healing. Western blotting and coimmunoprecipitation (co-IP) were used to determine the expression of DLC1 and CAV-1 and their interaction. Our data indicated that up-regulation of intracellular ROS induced by H₂O₂ significantly inhibited proliferation and induced apoptosis accompanying G1 cell cycle arrest and elevated expression of p53. For cell migration, either up-regulation or down-regulation of ROS induced migration inhibition with reduction of interaction between DLC1 and CAV-1. Our results suggested that up-regulation of intracellular ROS inhibited proliferation by promoting expression of p53 and induced G1 cycle arrest and apoptosis. Fluctuation of ROS inhibited migration through reducing the interaction between DLC1 and CAV-1.

The decay of Redox-stress Response Capacity is a substantive characteristic of aging: Revising the redox theory of aging

Aging is tightly associated with redox events. The free radical theory of aging indicates that redox imbalance may be an important factor in the aging process. Most studies about redox and aging focused on the static status of oxidative stress levels, there has been little research investigating differential responses to redox challenge during aging. In this study, we used Caenorhabditis elegans and human fibroblasts as models to compare differential responses to oxidative stress challenge in young and old individuals. In response to paraquat stress, young individuals generated more ROS and activated signaling pathways including p-ERK, p-AKT and p-AMPKα/β. After the initial response, young individuals then promoted NRF2 translocation and induced additional antioxidant enzymes and higher expression of phase II enzymes, including SOD, CAT, GPX, HO-1, GSTP-1and others, to maintain redox homeostasis. Moreover, young individuals also demonstrated a better ability to degrade damaged proteins by up-regulating the expression of chaperones and improving proteasome activity. Based on these data, we propose a new concept "Redox-stress Response Capacity (RRC)", which suggests cells or organisms are capable of generating dynamic redox responses to activate cellular signaling and maintain cellular homeostasis. The decay of RRC is the substantive characteristic of aging, which gives a new understand of the redox theory of aging.

LOX-1 and TLR4 affect each other and regulate the generation of ROS in A. fumigatus keratitis

PURPOSE

To explore the relationship between LOX-1 and TLR4 in Aspergillus fumigatus (A. fumigatus) keratitis. To determine LOX-1 and TLR4 can affect each other and regulate inflammation through regulation of the generation of reactive oxygen species (ROS) in A. fumigatus keratitis.

METHODS

The cornea and abdominal cavity extracted neutrophils of susceptible C57BL/6 mice were infected with A. fumigatus. The cornea and neutrophils were pretreated with LOX-1 neutralizing antibody, Polyinosinic acid (Poly(I)) (the inhibitor of LOX-1) or CLI-095 (the inhibitor of TLR4) separately before infection. LOX-1, TLR4 and IL-1β expression were detected in normal and infected cornea by PCR and Western Blot, while ROS was detected in the neutrophils by flow cytometry.

RESULTS

LOX-1, TLR4, IL-1β mRNA and protein levels were up-regulated in C57BL/6 cornea after infection. LOX-1 neutralizing antibody or Poly(I) pretreatment decreased the expression of LOX-1, TLR4 and IL-1β in C57BL/6 cornea after infection and CLI-095 pretreatment decreased the expression of LOX-1, TLR4 and IL-1β in C57BL/6 cornea after infection. ROS generation was increased in C57BL/6 neutrophils after infection, however, ROS generation was decreased in C57BL/6 neutrophils after infection by LOX-1 neutralizing antibody or Poly(I) or CLI-095 pretreatment.

CONCLUSION

LOX-1, TLR4 and IL-1β expression and ROS generation are increased after infection. LOX-1 and TLR4 can affect each other and regulate the generation of ROS in A. fumigatus keratitis. Inhibition of LOX-1 and TLR4 can reduce ROS generation.

Shikonin Induces Apoptotic Cell Death via Regulation of p53 and Nrf2 in AGS Human Stomach Carcinoma Cells

Shikonin, which derives from Lithospermum erythrorhizon, has been traditionally used against a variety of diseases, including cancer, in Eastern Asia. Here we determined that shikonin inhibits proliferation of gastric cancer cells by inducing apoptosis. Shikonin’s biological activity was validated by observing cell viability, caspase 3 activity, reactive oxygen species (ROS) generation, and apoptotic marker expressions in AGS stomach cancer cells. The concentration range of shikonin was 35–250 nM with the incubation time of 6 h. Protein levels of Nrf2 and p53 were evaluated by western blotting and confirmed by real-time PCR. Our results revealed that shikonin induced the generation of ROS as well as caspase 3-dependent apoptosis. c-Jun-N-terminal kinases (JNK) activity was significantly elevated in shikonin-treated cells, thereby linking JNK to apoptosis. Furthermore, our results revealed that shikonin induced p53 expression but repressed Nrf2 expression. Moreover, our results suggested that there may be a co-regulation between p53 and Nrf2, in which transfection with siNrf2 induced the p53 expression. We demonstrated for the first time that shikonin activated cell apoptosis in AGS cells via caspase 3- and JNK-dependent pathways, as well as through the p53-Nrf2 mediated signal pathway. Our study validates in partly the contribution of shikonin as a new therapeutic approaches/ agent for cancer chemotherapy.

Intracellular labile iron determines H2O2-induced apoptotic signaling via sustained activation of ASK1/JNK-p38 axis

Hydrogen peroxide (H2O2) acts as a second messenger in signal transduction participating in several redox regulated pathways, including cytokine and growth factor stimulated signals. However, the exact molecular mechanisms underlying these processes remain poorly understood and require further investigation. In this work, using Jurkat T lymphoma cells and primary human umbilical vein endothelial cells, it was observed that changes in intracellular "labile iron" were able to modulate signal transduction in H2O2-induced apoptosis. Chelation of intracellular labile iron by desferrioxamine rendered cells resistant to H2O2-induced apoptosis. In order to identify the exact points of iron action, we investigated selected steps in H2O2-mediated apoptotic pathway, focusing on mitogen activated protein kinases (MAPKs) JNK, p38 and ERK. It was observed that spatiotemporal changes in intracellular labile iron, induced by H2O2, influenced the oxidation pattern of the upstream MAP3K ASK1 and promoted the sustained activation of JNK-p38 axis in a defined time-dependent context. Moreover, we indicate that H2O2 induced spatiotemporal changes in intracellular labile iron, at least in part, by triggering the destabilization of lysosomal compartments, promoting a concomitant early response in proteins of iron homeostasis. These results raise the possibility that iron-mediated oxidation of distinct proteins may be implicated in redox signaling processes. Since labile iron can be pharmacologically modified in vivo, it may represent a promising target for therapeutic interventions in related pathological conditions.