Induced Cell Damage Research Articles

Octopamine-MAPK-SKN-1 signaling suppresses mating-induced oxidative stress in Caenorhabditis elegans gonads to protect fertility

Sexual conflict over mating is costly to female physiology. Caenorhabditis elegans hermaphrodites generally produce self-progeny, but they can produce cross-progeny upon successfully mating with a male. We have uncovered that C.elegans hermaphrodites experience sexual conflict over mating, resulting in severe costs in terms of their fertility and longevity. We show that reactive oxygen species (ROS) accumulate on the apical surfaces of spermathecal bag cells after successful mating and induce cell damage, leading to ovulation defects and fertility suppression. To counteract these negative impacts, C.elegans hermaphrodites deploy the octopamine (OA) regulatory pathway to enhance glutathione (GSH) biosynthesis and protect spermathecae from mating-induced ROS. We show that the SER-3 receptor and mitogen-activated protein kinase (MAPK) KGB-1 cascade transduce the OA signal to transcription factor SKN-1/Nrf2 in the spermatheca to upregulate GSH biosynthesis.

Hispidin in the Medicinal Fungus Protects Dopaminergic Neurons from JNK Activation-Regulated Mitochondrial-Dependent Apoptosis in an MPP+-Induced In Vitro Model of Parkinson's Disease.

Degenerative diseases of the brain include Parkinson's disease (PD), which is associated with moveable signs and is still incurable. Hispidin belongs to polyphenol and originates primarily from the medicinal fungi Inonotus and Phellinus, with distinct biological effects. In the study, MES23.5 cells were induced by 1-methyl-4-phenylpyridinium (MPP+) to build a cell model of PD in order to detect the protective effect of hispdin and to specify the underlying mechanism. Pretreatment of MES23.5 cells with 1 h of hispdin at appropriate concentrations, followed by incubation of 24 h with 2 μmol/L MPP+ to induce cell damage. MPP+ resulted in reactive oxygen species production that diminished cell viability and dopamine content. Mitochondrial dysfunction in MS23.5 cells exposed to MPP+ was observed, indicated by inhibition of activity in the mitochondrial respiratory chain complex I, the collapse of potential in mitochondrial transmembrane, and the liberation of mitochondrial cytochrome c. Enabling C-Jun N-terminal kinase (JNK), reducing Bcl-2/Bax, and enhancing caspase-9/caspase-3/PARP cleavage were also seen by MPP+ induction associated with increased DNA fragmentation. All of the events mentioned above associated with MPP+-mediated mitochondrial-dependent caspases cascades were attenuated under cells pretreatment with hispidin (20 µmol/L); similar results were obtained during cell pretreatment with pan-JNK inhibitor JNK-IN-8 (1 µmol/L) or JNK3 inhibitor SR3576 (25 µmol/L). The findings show that hispidin has neuroprotection against MPP+-induced mitochondrial dysfunction and cellular apoptosis and suggest that hispidin can be seen as an assist in preventing PD.

The HL-60 human promyelocytic cell line constitutes an effective in vitro model for evaluating toxicity, oxidative stress and necrosis/apoptosis after exposure to black carbon particles and 2.45 GHz radio frequency

The cellular and molecular mechanisms by which atmospheric pollution from particulate matter and/or electromagnetic fields (EMFs) may prove harmful to human health have not been extensively researched. We analyzed whether the combined action of EMFs and black carbon (BC) particles induced cell damage and a pro-apoptotic response in the HL-60 promyelocytic cell line when exposed to 2.45 GHz radio frequency (RF) radiation in a gigahertz transverse electromagnetic (GTEM) chamber at sub-thermal specific absorption rate (SAR) levels. RF and BC induced moderately significant levels of cell damage in the first 8 or 24 h for all exposure times/doses and much greater damage after 48 h irradiation and the higher dose of BC. We observed a clear antiproliferative effect that increased with RF exposure time and BC dose. Oxidative stress or ROS production increased with time (24 or 48 h of radiation), BC dose and the combination of both. Significant differences between the proportion of damaged and healthy cells were observed in all groups. Both radiation and BC participated separately and jointly in triggering necrosis and apoptosis in a programmed way. Oxidative-antioxidant action activated mitochondrial anti-apoptotic BCL2a gene expression after 24 h irradiation and exposure to BC. After irradiation of the cells for 48 h, expression of FASR cell death receptors was activated, precipitating the onset of pro-apoptotic phenomena and expression and intracellular activity of caspase-3 in the mitochondrial pathways, all of which can lead to cell death. Our results indicate that the interaction between BC and RF modifies the immune response in the human promyelocytic cell line and that these cells had two fates mediated by different pathways: necrosis and mitochondria-caspase dependent apoptosis. The findings may be important in regard to antimicrobial, inflammatory and autoimmune responses in humans.

Blueberry stem extract and stem active components prevent blue light-emitting diode light-induced retinal photoreceptor cell damage in vitro.

Blue light causes retinal damage that can lead to ocular diseases such as age-related macular degeneration. In this study, we determined the protective effect of blueberry stem extract (BStEx) and active components on blue light-emitting diode (LED) light-induced retinal photoreceptor cell damage in vitro. Photoreceptor cells cultured in the presence of BStEx or components were exposed to blue light to induce cell damage. BStEx, fractions of BStEx containing proanthocyanidins, chlorogenic acid, catechin, and epicatechin prevented the cell damage and/or inhibited the generation of reactive oxygen species (ROS). Furthermore, BStEx reduced apoptosis and cell death, and inhibited the phosphorylation of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase leading to cellular apoptosis induced by blue light exposure. These findings suggest that BStEx and components exert a protective effect against blue light-induced photoreceptor cell damage through the inhibition of MAPK phosphorylation and ROS production.

Tranilast protects pancreatic β-cells from palmitic acid-induced lipotoxicity via FoxO-1 inhibition

Tranilast, an anti-allergic drug used in the treatment of bronchial asthma, was identified as an inhibitor of the transcription factor Forkhead box O-1 (FoxO-1) by high throughput chemical library screening in the present study. Based on FoxO-1’s role in apoptotic cell death and differentiation, we examined the effect of tranilast on palmitic acid (PA)-induced cell damage in INS-1 cells. Tranilast substantially inhibited lipoapoptosis and restored glucose-stimulated insulin secretion under high PA exposure. Moreover, PA-mediated downregulation of PDX-1, MafA, and insulin expression was attenuated by tranilast. PA-induced oxidative and ER stress were also reduced in the presence of tranilast. These protective effects were accompanied by increased phosphorylation and decreased nuclear translocation of FoxO-1. Conversely, the effects of tranilast were diminished when treated in transfected cells with FoxO-1 phosphorylation mutant (S256A), suggesting that the tranilast-mediated effects are associated with inactivation of FoxO-1. Examination of the in vivo effects of tranilast using wild type and diabetic db/db mice showed improved glucose tolerance along with FoxO-1 inactivation in the pancreas of the tranilast-treated groups. Thus, we report here that tranilast has protective effects against PA-induced lipotoxic stress in INS-1 cells, at least partly, via FoxO-1 inactivation, which results in improved glucose tolerance in vivo.

Neuroprotective Effect of the Mixture of Gastrodiae elata and Glycyrrhizae uralensis In Vitro

Background: This study investigated the effect of a mixture of Gastrodiae elata and Glycyrrhizae uralensis (GGW) on β-amyloid-induced neuronal damage in vitro. Methods: For finding the appropriate GGW ratio, we performed MTT assays using the ratios of 5:5, 6:4, 7:3, 8:2 and 9:1 in SK-N-SH cell and SH-SY-5Y cell. Treatment with β-amyloid (10 μM) caused cell death and overexpression of acetylcholinesterase (ACHE) in SH-SY-5Y cells. β-amyloid treatment increased the expression of mitogen-activated protein kinases (MAPKs). In addition, we detected the antioxidant activity of GGW using DCF-DA staining of SK-N-SH cells. To determine the effect of GGW on oxidative stress, we used a hydrogen peroxidase-induced in vitro model. Results: We selected the ratios of 5:5 and 7:3 mixtures with the least cytotoxicity. The 7:3 ratio of GGW (GGW73) decreased the mRNA expression of ACHE in SH-SY-5Y cell more than the 5:5 ratio of GGW (GGW55). GGW73 suppressed p-ERK protein expression in β-amyloid-treated SH-SY-5Y cells. Additionally, GGW73 regulated reactive oxygen species (ROS) in vitro. GGW73 treatment regulated apoptotic factors in β-amyloid-stimulated neuronal cells. Conclusions: These results suggest that GGW73 exerts neuroprotective and anti-inflammatory effects in vitro. These results also showed that GGW73 had a protective effect against H2O2 induced cell damage in an in vitro model. These results indicate the potential of GGW as a therapeutic agent for cognitive disorders.

Antioxidant Effects of Rhodoxanthin from Potamogeton crispus L. on H2 O2 -Induced RAW264.7 Macrophages Cells.

Potamogeton crispus L. (P. crispus) is the type of a widely distributed perennial herbs, which is rich in rhodoxanthin. In this research work, five antioxidant indexes in vitro were selected to study the antioxidant activity of rhodoxanthin from P. crispus (RPC). A model of hydrogen peroxide (H2 O2 ) -induced oxidative damage in RAW264.7 cells was established to analyze the antioxidant effect and potential mechanism of RPC. The levels of ROS, MDA and the activities of oxidation related enzymes by H2 O2 were determined by enzyme linked immunosorbent assay (ELISA). The mRNA expression of Nrf-2, HO-1, SOD1 and SOD2 was measured by qRT-PCR assay. According to the results, RPC had free radical scavenging ability for 2, 2-diphenyl-1-trinitrohydrazine (DPPH), 2,2'-azinobis(3-ethylbenzo-thiazoline-6-sulfonic acid radical ion) (ABTS), hydroxyl radical and superoxide anion. RPC significantly decreased the level of MDA and ROS and LDH activity, while increased GSH level and activities of SOD, GSH-Px and CAT. It was showed that RPC could increase the mRNA expression of Nrf-2, HO-1, SOD1 and SOD2 in RAW264.7 cells in a dose-dependently manner. In summary, RPC treatment could effectively attenuate the H2 O2 -induced cell damage rate, and the mechanism is related to the reduction of H2 O2 induced oxidative stress and the activation of Nrf-2 pathway.

Is the level of serum lactate dehydrogenase a potential biomarker for glucose monitoring with type 2 diabetes mellitus?

Type 2 diabetes mellitus (T2DM) is a metabolic disorder due to defects in insulin secretion or insulin resistance leading to the dysfunction and damage of various organs. To improve the clinical evaluation of short-term blood glycemic variability monitoring, it is critical to identify another blood cell status and nutritional status biomarker that is less susceptible to interference. This study identifies the significance of serum lactate dehydrogenase (LDH) level among T2DM patients treated in outpatient clinics and investigates the relationship of LDH level with other variables. This study comprised 72 outpatients with T2DM over 20 years of age. Blood samples were collected followed by a hematological analysis of serum glycated albumin (GA), LDH, fasting blood glucose, glycosylated hemoglobin, C-peptide, and insulin antibodies (insulin Ab). Serum LDH level was significantly correlated with GA (p < 0.001), C-peptide (p = 0.04), insulin Ab (p = 0.03), and thyroid-stimulating hormone (TSH) levels (p = 0.04). Hence, we performed a linear regression analysis of hematological markers. GA (p < 0.001, r2 = 0.45) and insulin Ab (p < 0.001, r2 = 0.40) were significantly associated with LDH level. Then, we classified patients into low (<200 U/L) and high (≥200 U/L) serum LDH level groups, respectively. GA (p < 0.001), C-peptide (p = 0.001), and TSH (p = 0.03) showed significant differences in patients with high LDH levels compared with those in patients with low LDH levels. In conclusion, we suggested that LDH level was independent of long-term but associated with short-term blood glucose monitoring. The results indicated that changes in serum GA induced cell damage and the abnormal elevation of the serum level of LDH may occur simultaneously with glycemic variability. It has been reported that many biomarkers are being used to observe glucose variability in T2DM. However, LDH could provide a more convenient and faster evaluation of glycemic variability in T2DM.

Effects of Alternanthera sessilis Red leaf extracts on hydrogen peroxide-induced oxidative stress in HepG2 cells and identification of phytochemicals using HPLC-QToF-MS/MS

Alternanthera sessilis Red (ASR) is an edible medicinal plant that receives little attention in Asia. This study aimed to investigate the ability of ASR ethanolic (EtOH ASR ) and ethyl acetate (EtAC ASR ) leaf extracts in protecting HepG2 cells against oxidative damage. To determine the effect of both extracts on the cellular antioxidant status and preventive activities against hydrogen peroxide (H 2 O 2 )-induced oxidative stress, HepG2 cells were treated with both extracts at concentration ≤ 20 µg/mL as the extracts were shown low toxicity. With increasing concentrations, both extracts improved cellular antioxidant status where cells treated with EtAC ASR showed a higher ferric reducing activity than the EtOH ASR . Both extracts also reduced the levels of reactive oxygen species and inhibited lipid peroxidation in the cells. The highest cytoprotective activity against H 2 O 2 -induced cell damage was exhibited by EtAC ASR at 5 µg/mL. HPLC-QToF-MS/MS analysis tentatively identified the presence of 30 phytochemicals in both extracts with 28 of them comprising of polyphenols, whereas two carotenoids were found only in the EtOH ASR . These may be responsible for the cytoprotective properties of the ASR leaf. The current findings highlight the potential of ASR leaf as a source of natural antioxidants for protecting cells from oxidative damage. Furthermore, newly discovered phytochemical compounds in ASR, particularly polyphenols, which are mostly flavonoids, could be useful for future research into its potential as a functional food or nutraceutical against oxidative stress-related diseases. • EtOH ASR and EtAC ASR significantly protected HepG2 cells against oxidative stress. • EtAC ASR inhibited intracellular ROS more effectively at 5 µg/mL. • EtAC ASR was also better in reducing lipid peroxidation induced by H 2 O 2 at 5 µg/mL. • Two carotenoids and 28 polyphenols were tentatively identified in the extracts.

Evaluation of the effect of UV-B radiation on growth, photosynthetic pigment, and antioxidant enzymes of some cyanobacteria

The current study is focused on the effects of artificial UV-B radiation on growth, proteins, and pigments, as well as the activities of several enzymatic and non-enzymatic antioxidant enzymes in some cyanobacterial strains. Cultures were maintained at 25 °C ± 1 °C under a white fluorescent tube of intensity 30–40 μE m -2s−1 with a 14:10 light and dark cycle in the laboratory and analyzed at an interval of 25, 32, 39, 46, and 53 days. The test cultures were exposed to UV-B stress for 24 h at the same intervals. We found that exposure to UV-B showed increased production of phycocyanin and carotenoids in four strains, namely, Scytonema javanicum, Nostoc muscorum, Aphanothece naegeli, and Synechococcus elongates. We also look into the effects of UV-B radiation on the proline content, non-protein thiols, radical scavenging activity, ascorbic acid, and tocopherol, total flavonoid content (TFC), total phenolic content (TPC) on these strains. Variation in the non-enzymatic antioxidants and expression levels of enzymatic enzymes and reducing power activity as compared to the non-irradiated control was found. Our study showed that cyanobacteria impart prominent antioxidant and radical scavenging properties which facilitate the defence mechanism against UV-B induced cell damage.

Adenosine A1 receptor agonism protection mechanism in intestinal ischemia/reperfusion injury via activation of PI3K/Akt signaling.

Intestinal ischemia/reperfusion (I/R) injury is a common clinical problem with a high mortality rate, resulting from loss of blood flow to an intestinal segment. Adenosine serves a protective role in intestinal I/R injury; however, its potential mechanism is not completely understood. The present study aimed to investigate the protective effects of adenosine A1 receptor (A1R) agonists CPA and LUF6941 and whether their mechanisms are associated with the PI3K/Akt signaling pathway. To simulate intestinal I/R injury, a cell oxygen-glucose deprivation/reoxygenation (OGD/R) model was established and the human colon cancer cell line (Caco-2) was incubated with A1R agonists before OGD/R treatment. The viability of Caco-2 cells was detected by PI and Cell Counting Kit-8 assay, apoptosis was detected using flow cytometry and western blotting was used to analyze protein expression levels of PI3K, Akt and p53 in Caco-2 cells. A1R agonist pretreatment protected Caco-2 cells against OGD/R-induced cell damage and activated PI3K/Akt signaling. Additionally, apoptosis was inhibited by downregulating phosphorylation of p53 protein, as evidenced by increased cell viability. These findings suggested that A1R agonists decreased OGD/R damage in Caco-2 cells, which may be due to their anti-apoptotic effects and activation of the PI3K/Akt/p53 signal pathway.

Neuroprotective effects of a lead compound from coral via modulation of the orphan nuclear receptor Nurr1.

To screen coral-derived compounds with neuroprotective activity and clarify the potential mechanism of lead compounds. The lead compounds with neuroprotective effects were screened by H2 O2 and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPP+ )-induced cell damage models in SH-SY5Y cells. CCK8 and LDH assays were used to detect cell viability. The anti-apoptosis of lead compounds was evaluated by flow cytometry. JC-1 and MitoSox assays were performed to examine the changes in mitochondrial membrane potential and mitochondrial ROS level. Survival of primary cortical and dopaminergic midbrain neurons was measured by MAP2 and TH immunoreactivities. The Caenorhabditis elegans (C. elegans) model was established to determine the effect of lead compounds on dopaminergic neurons and behavior changes. Three compounds (No. 63, 68, and 74), derived from marine corals, could markedly alleviate the cell damage and notably reverse the loss of worm dopaminergic neurons. Further investigation indicated that compound 63 could promote the expression of Nurr1 and inhibit neuronal apoptosis signaling pathways. Lead compounds from marine corals exerted significant neuroprotective effects， which indicated that coral might be a new and potential resource for screening and isolating novel natural compounds with neuroprotective effects. Furthermore, this study also provided a new strategy for the clinical treatment of neurodegenerative diseases such as Parkinson's disease.

Photoinduced Carbene for Effective Photodynamic Therapy Against Hypoxic Cancer Cells

Photoinduced Carbene for Effective Photodynamic Therapy Against Hypoxic Cancer Cells

Ferritin confers protection against iron-mediated neurotoxicity and ferroptosis through iron chelating mechanisms in MPP+-induced MES23.5 dopaminergic cells.

Ferritin is the main iron storage protein and plays an important role in maintaining iron homeostasis. In a previous study, we reported that apoferritin exerted a neuroprotective effect against MPTP by regulation of brain iron metabolism and ferroptosis. However, the precise cellular mechanisms of extracellular ferritin underlying this protection are not fully elucidated. Ferritin was reported to be localized in different intracellular compartments, cytoplasm or released outside cells. Here we demonstrated that the intracellular iron increased after iron treatment in primary cultured astrocytes. These iron-loaded astrocytes released more ferritin in order to buffer extracellular iron. Using co-culture system of primary cultured astrocytes and MES23.5 dopaminergic cells, we showed that ferritin released by astrocytes could enter MES23.5 dopaminergic cells. And primary cultured astrocytes protected MES23.5 dopaminergic cells against 1-methyl-4-phenylpyridinium ion (MPP+)-induced neurotoxicity and ferroptosis. In addition, we found that exogenous Apoferritin or Ferritin pretreatment could significantly inhibit MPP+-induced cell damage by restoring the cell viability and mitochondrial transmembrane potential (ΔΨm). Furthermore, exogenous Apoferritin and Ferritin might also protect MES23.5 dopaminergic cells against MPP+ by decreasing reactive oxygen species (ROS) and inhibiting the increase of the labile iron pool (LIP). This suggests that astrocytes increased ferritin release to respond to iron overload, which might inhibit iron-mediated oxidative damage and ferroptosis of dopamine (DA) neurons in Parkinson's disease (PD).

차나무 부위별 추출물의 미백, 주름 개선과 피부보호 효과

Background: Camellia sinensis is globally cultivated, principally for the leaves which are used as a green tea. Green tea made from C. sinensis leaves contains various physiologically active ingredients and is used for health and beauty purposes; however, most parts of the plant are discarded. In this experiment the physiological activity of each part of the C. sinensis was analyzed to confirm its potential for use as a cosmetic raw material.BR Methods and Results: Leaves, flowers, roots, branches, and seeds were extracted with 70% ethyl alcohol. Experiments were performed to measure, tyrosinase inhibitory activity, elastase inhibitory activity, antibacterial activity, and cell viability upon ultraviolet B (UVB)-induced cell damage. Tyrosinase inhibitory activity was high in leaves, flowers, and roots, and elastase inhibitory activity showed high inhibition rates in roots, leaves, and branches. Antibacterial activity against Propionibacterium acnes was highest in leaves and roots, followed by branches and flowers, with no antibacterial activity found in seeds. In terms of the protective effect from UVB irradiation induced damage, the experimental group treated with the seed extract in HaCaT cells showed a high survival rate. In Detroit cells, an increased survival rate was observed in most of the experimental groups treated with the extracts, particularly those treated with the seed and flower extracts.BR Conclusions: Experiment results suggest various parts of the C. sinensis, could be used as raw materials for cosmetics.

Kinesin spindle protein inhibitor exacerbates cisplatin-induced hair cell damage

There is emerging evidence indicating that Kinesin family, plays vital roles in influencing the growth of axons, interference with the progression of tumor. However, the function of Kinesin member in the auditory organs remains unknown. SB743921, a kinesin spindle protein (KSP) inhibitor, was applied in mouse organ of Corti and House Ear Institute-Organ of Corti 1 (HEI-OC1) cell line to examine the role of KSP in auditory system with and without cisplatin damage. Cell Counting Kit-8 (CCK-8) and Lactase dehydrogenase (LDH) release assay were conducted to evaluate cell activity and toxicity. Pretreatment with SB743921 increased the sensitivity of HEI-OC1 cells to cisplatin ototoxicity through promoting cell apoptosis and deteriorating superoxide generation mediated damage from cisplatin. SB743921 also enhanced cisplatin induced hair cell damage in explants of mouse cochleae in vitro. Furthermore, the combined N-acetylcysteine (NAC) treatment with cisplatin or with cisplatin and SB743921 both completely rescued the reduced number of hair cells impaired by cisplatin, confirming the strengthening function of superoxide accumulation by SB743921 after cisplatin treatment. Inhibition of kinesin spindle protein enhanced the susceptibility of hair cells to cisplatin induced damage in mouse cochlear explants and HEI-OC1 cells, indicating that kinesin spindle protein might be an unprecedented target to weaken the ototoxicity of platinum medicaments.

Limosilactobacillus fermentum Strain 3872: Antibacterial and Immunoregulatory Properties and Synergy with Prebiotics against Socially Significant Antibiotic-Resistant Infections of Animals and Humans.

Limosilactobacillus fermentum strain 3872 (LF3872) was originally isolated from the breast milk of a healthy woman during lactation and the breastfeeding of a child. The high-quality genome sequencing of LF3872 was performed, and a gene encoding a unique bacteriocin was discovered. It was established that the bacteriocin produced by LF3872 (BLF3872) belongs to the family of cell-wall-degrading proteins that cause cell lysis. The antibacterial properties of LF3872 were studied using test cultures of antibiotic-resistant Gram-positive and Gram-negative pathogens. Gram-positive pathogens (Staphylococcus aureus strain 8325-4 and S. aureus strain IIE CI-SA 1246) were highly sensitive to the bacteriolytic action of LF3872. Gram-negative pathogens (Escherichia coli, Salmonella strains, and Campylobacter jejuni strains) were more resistant to the bacteriolytic action of LF3872 compared to Gram-positive pathogens. LF3872 is a strong co-aggregator of Gram-negative pathogens. The cell-free culture supernatant of LF3872 (CSLF3872) induced cell damage in the Gram-positive and Gram-negative test cultures and ATP leakage. In the in vitro experiments, it was found that LF3872 and Actigen prebiotic (Alltech Inc., Nicholasville, KY, USA) exhibited synergistic anti-adhesive activity against Gram-negative pathogens. LF3872 has immunoregulatory properties: it inhibited the lipopolysaccharide-induced production of proinflammatory cytokines IL-8, IL-1β, and TNF-α in a monolayer of Caco-2 cells; inhibited the production of IL-12 and stimulated the production of IL-10 in immature human dendritic cells; and stimulated the production of TGF-β, IFN-γ, and IgA in the immunocompetent cells of intestinal Peyer’s patches (PPs) in mice. These results indicate the possibility of creating a synbiotic based on LF3872 and a prebiotic derived from Saccharomyces cerevisiae cell wall components. Such innovative drugs and biologically active additives are necessary for the implementation of a strategy to reduce the spread of antibiotic-resistant strains of socially significant animal and human infections.

Involvement of microRNA/cystine/glutamate transporter in cold-stressed gastric mucosa injury.

Stress ulcers are complicated by severe trauma and other critical diseases, the mechanism of which remains unclear. An increasing number of studies have shown that microRNAs (miRNAs) are important regulators of stress responses such as hypoxia, abnormal temperature, and inflammation. The evidence indicates that miRNAs are also involved in regulating stress-induced ulcers. Recently, we demonstrated that gastric mucosal injury induced by aspirin is related to the reduction of glutamate levels by inhibition of cystine/glutamate transporter (xCT) activity. In the present study, the effect of a miRNA/xCT on gastric mucosal injury induced by cold stimulation was investigated. We found that cold stimulation induced gastric mucosa injury with a reduction in glutamate levels and xCT activity and upregulation of miR-143, miR-152, and miR-181 expression. Exogenous glutamate significantly alleviated gastric mucosa injury by cold stimulation. In vitro experiments demonstrated that treatment with miR-143, miR-152, or miR-181 mimics directly induced cell damage. The effects of these mimics were alleviated by exogenous glutamate. The present study suggests that miR-143, miR-152, and miR-181 are involved in cold stimulation-induced acute gastric mucosal injury. Furthermore, the regulatory effect of miRNAs on gastric mucosa injury induced by cold stimulation is related to a decrease in glutamate release by reduction of cystine/glutamate transporter activity.

Zearalenone Promotes LPS-Induced Oxidative Stress, Endoplasmic Reticulum Stress, and Accelerates Bovine Mammary Epithelial Cell Apoptosis.

Both zearalenone (ZEA) and lipopolysaccharide (LPS) can induce oxidative stress, and even apoptosis in bovine mammary epithelial cells (MAC-T), but not much attention has been given to the synergistic effect of ZEA and LPS. In this study, we treated MAC-T cells with different concentrations of LPS (1, 10, 50, and 100 μg/mL) and ZEA (5, 15, and 30 μM) to induce cell damage. Previous results show that MAC-T cell viability decreases with increasing LPS concentration. Meanwhile, 1 µg/mL LPS and ZEA were selected for combined treatment in subsequent studies. It was found that co-treatment with ZEA and LPS increases the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), decreases mitochondrial membrane potential (MMP), and superoxide dismutase (SOD), and reduces glutathione (GSH). ZEA and LPS are found to activate endoplasmic reticulum (ER) stress by increasing the expression of glucose-regulated protein 78 kDa (GRP78), activating transcription factor 6 (ATF6) and C/EBP homologous protein (CHOP). It increases cell apoptosis by suppressing the expression of the anti-apoptotic protein B-cell lymphoma-2 (Bcl-2), indicated by up-regulation of Bcl2-associated X protein (Bax) and Cysteinyl aspartate-specific proteinases 3 (caspase-3) expression. The above results suggest that the synergistic effect of ZEA and LPS aggravate cytotoxicity.

Toxicity mechanism of patulin on 293T cells and correlation analysis of Caspase family.

Patulin (PAT), a kind of mycotoxin, is a widely disseminated mycotoxin found in agricultural products. Although the existing research results show that PAT can cause nerve, immune, and skin toxicities, resulting in heart, liver, and kidney damages. However, evidence on the underlying mechanisms of PAT is still lacking. Present study aims to investigate the renal toxicity and related mechanisms of PAT on 293T cells. Cell Counting Kit-8 method was used to reveal the dose-effect relationship and the time-effect relationship of PAT toxicity. Trypan blue staining and Hoechst 33342 staining were used to analyze PAT, which induced apoptosis on 293T cells. Superoxide-dismutase (SOD), GSH, and malondialdehyde (MDA) were used to measure the changes of oxidative stress status of 293T cells induced by PAT. The changes of reactive oxygen species (ROS) and ATP in mitochondria indicate the role of mitochondria when PAT induced cell damage and apoptosis. Through Cyt-C release assay analysis, caspase activity change, and correlation analysis, the potential mechanism of mitochondrial apoptosis pathway was proved. Results demonstrated that PAT significantly induced cell injury, and with the increase of time and concentration, the cell survival rate decreased significantly. Hoechst 33342 staining and Trypan blue staining showed that apoptosis rate was elevated by PAT. As PAT concentration increased, intracellular SOD, glutathion peroxidase activities were decreased and the MDA content was increased. The decrease of intracellular ATP level and accumulation of ROS content indicated an increased permeability of the mitochondrial membrane. Overexpression of Cyt-C activated the cascade reaction of caspase enzyme, leading to apoptosis. The results of enzyme activity assay and correlation analysis indicated that caspase 3 was the most critical caspase in the cascade system and that it was most correlated with caspase 8 and caspase 9.