Oxidative Cell Injury Research Articles

EMP1 knockdown mitigated high glucose-induced pyroptosis and oxidative stress in rat H9c2 cardiomyocytes by inhibiting the RAS/RAF/MAPK signaling pathway.

The purpose of this study was to investigate the mechanism of EMP1 action in high glucose (HG)-induced H9c2 cardiac cell pyroptosis and oxidative injury. Rat cardiomyocytes H9c2 were exposed to 33 mM glucose for 24, 48, or 72 h to induce cytotoxicity. EMP1-siRNA, NLRP3 agonist Nigericin, and pcNDA-RAS were used to treat H9c2 cells under HG conditions. Cell Counting Kit (CCK)-8 assay showed that cell proliferation was decreased following HG induction, which was rescued by EMP1 knockdown. Our results also suggested that EMP1 siRNA transfection significantly decreased the apoptosis and pyroptosis of HG-induced cells, as indicated by the reduction of NLRP3 IL-1β, ASC, GSDMD, cleaved-caspase1 and cleaved-caspase3 levels in HG-induced H9c2 cells. In addition, EMP1 knockdown alleviated HG-induced mitochondrial damage and oxidative stress in H9c2 cells. NLRP3 activation reversed the inhibitory effects of EMP1 knockdown on pyroptosis and oxidative stress in HG-induced H9c2 cells. Mechanistically, we found that EMP1 knockdown suppressed the RAS/RAF/MAPK signaling pathway in HG-induced H9c2 cells. RAS overexpression blocked the protective effect of EMP1 knockdown on HG-induced H9c2 cell apoptosis, pyroptosis, and oxidative injury. Our findings suggest that EMP1 knockdown treatment might provide a novel therapy for diabetic cardiomyopathy.

The novel secretome ST266 activates Akt and protects against oxidative stress-mediated injury in human RPE and Müller cells

Oxidative stress-mediated retinal pigment epithelial (RPE) cell damage is associated with age-related macular degeneration (AMD). ST266 is the biological secretome produced by a novel population of amnion-derived multipotent progenitor cells. Herein, we investigated the effect of ST266 on RPE cell injury induced by hydroquinone (HQ), a cigarette smoke related oxidant, hydrogen peroxide (H2O2) and all-trans retinal (atRal), a pro-oxidant component of the retinoid cycle. We additionally investigated its effect on Müller cell injury induced by H2O2.Cultured human RPE cells were pre-treated for 1 hour in the presence or absence of MK-2206, a protein kinase B (Akt) inhibitor, then treated with varying concentrations of HQ, H2O2, or atRal for 1.5 hours. Cultured human Müller cells (MIO-M1) were pre-treated for 1 hour in the presence or absence of MK-2206, then treated with varying concentrations of H2O2 for 1.5 hours. Media were then replaced with STM100 (control media into which the ST266 secretome proteins were collected) or ST266 at various times. Cell viability was determined with WST-1 reagent. Mitochondrial membrane potential (Δψm) was quantified by a fluorescence plate reader. The protein phosphorylation levels of Akt, glycogen synthase kinase 3 beta (GSK-3β), and p70 ribosomal S6 kinase (p70S6K) were measured by Western blot.ST266 significantly improved RPE and MIO-M1 cell viability that was reduced by oxidant exposure and improved oxidant-disrupted Δψm. In both cell types, ST266 induced phosphorylation of Akt, GSK-3β, and p70S6K. MK-2206 significantly eliminated ST266-mediated protein phosphorylation of Akt, GSK-3β, and p70S6K and abolished the ST266-protective effect on cell viability. In conclusion, ST266 activates Akt, protects against oxidative stress-mediated cell injury in an Akt-dependent manner, and improves Δψm, suggesting a potential role for ST266 therapy in treating retinal diseases such as AMD.

Exploring the Cardiovascular Protective Effects of Baicalin: A Pathway to New Therapeutic Insights.

Cardiovascular disorders develop the highest rates of mortality and morbidity worldwide, emphasizing the need for novel pharmacotherapies. The Chinese medicinal plant S. baicalensis has a number of major active components, one of which is called baicalin. According to emerging research, baicalin reduces chronic inflammation, immunological imbalance, lipid metabolism, apoptosis, and oxidative stress. Baicalin improves endothelial function and protects the cardiovascular system from oxidative stress-induced cell injury by scavenging free radicals and inhibiting xanthine oxidase. Therefore, it helps prevent CVD such as hypertension, atherosclerosis, and cardiac arrest. In this review, the therapeutic effects of baicalein are discussed in relation to both the prevention and management of cardiovascular diseases.

Assessment of Add-On Therapy of N-Acetylcysteine in the Management of Acute Pancreatitis

Abstract Background Acute pancreatitis (AP) is an inflammation of the pancreas. The conservative therapeutic options include enteral nutrition, antibiotics, and/or surgery. Oxidative stress in AP has been pathologically linked with the systemic inflammatory response. N-acetylcysteine (NAC), an antioxidant, attenuates oxidative stress-induced cell injury and other potential pathological events in AP. Objective This article evaluates the treatment outcome of NAC combined with conventional therapy in AP patients and assesses the difference in the duration of hospital stay between the NAC with conventional therapy group and the conventional therapy group. Materials and Methods This observational study was conducted in a tertiary care hospital with 65 AP patients above 18 years of age. The effect of adding NAC with conventional therapy (intravenous hydration 0.9% normal saline, pancreatin, optional antibiotics) was assessed in patients by comparing serum amylase, lipase, Acute Physiology and Chronic Health Examination (APACHE) II score, and Ranson's score, before and after therapy and the difference in duration of hospital stay was assessed using the independent t-test. Results Of the 65 AP patients, 62% (n = 40) were on conventional therapy and 38% (n = 25) were on NAC along with conventional therapy. The difference in mean values of reduced serum amylase between the two treatment groups indicates a significant difference (p = 0.01). However, the variance in mean serum lipase values was statistically insignificant (p = 0.1). The mean scores of Ranson's criteria showed no significant difference between both groups (p = 0.4). There was a significant difference in APACHE II severity scores after 24 (p = 0.04) and 48 hours (p = 0.01), respectively. Similarly, the mean duration of hospital stay in both treatment groups was found to be statistically insignificant (p = 0.4). Conclusion Both treatment options, conventional therapy and NAC combined with conventional therapy, resulted similar treatment outcomes for AP patients, with no additional benefits observed.

LncRNA-SNHG16 Protects Against Oxidative Stress-Induced Vascular Endothelial Cell Injury in Cardiovascular Diseases by Regulating the miR-23a-3p-GLS-Glutamine Metabolism Axis.

Cardiovascular diseases are disorders of the heart and vascular system that cause high mortality rates worldwide. Vascular endothelial cell (VEC) injury caused by oxidative stress (OS) is an important event in the development of various cardiovascular diseases, including ischemic heart disease. This study aimed to investigate the critical roles and molecular mechanisms of long non-coding RNA (lncRNA) SNHG16 in regulating vascular endothelial cell injury under oxidative stress. We demonstrated that SNHG16 was significantly downregulated and miRNA-23a-3p was notably induced in human vascular endothelial cells under OS. Overexpressing SNHG16 or silencing miR-23a-3p effectively mitigated the OS-induced VEC injury. Additionally, glutamine metabolism of VECs was suppressed under OS. SNHG16 protected the OS-suppressed glutamine metabolism, while miR-23a-3p functioned oppositely in VECs. Furthermore, SNHG16 downregulated miR-23a-3p by sponging miR-23a-3p, which direct targeted the glutamine metabolism enzyme, GLS. Finally, restoring miR-23a-3p in SNHG16-overexpressing VECs successfully reversed the protective effect of SNHG16 on vascular endothelial cell injury under OS. In summary, our results revealed the roles and molecular mechanisms of the SNHG16-mediated protection against VEC injury under OS by modulating the miR-23a-3p-GLS pathway.

Exploring the key role of DNA methylation as an epigenetic modulator in oxidative stress related islet cell injury in patients with type 2 diabetes mellitus: a review

Exploring the key role of DNA methylation as an epigenetic modulator in oxidative stress related islet cell injury in patients with type 2 diabetes mellitus: a review

Progesterone (P4) ameliorates cigarette smoke-induced chronic obstructive pulmonary disease (COPD)

BackgroundChronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease associated with high morbidity and mortality worldwide. Oxidative injury and mitochondrial dysfunction in the airway epithelium are major events in COPD progression.Methods and resultsThe therapeutic effects of Progesterone (P4) were investigated in vivo and in vitro in this study. In vivo, in a cigarette smoke (CS) exposure-induced COPD mouse model, P4 treatment significantly ameliorated CS exposure-induced physiological and pathological characteristics, including inflammatory cell infiltration and oxidative injury, in a dose-dependent manner. The c-MYC/SIRT1/PGC-1α pathway is involved in the protective function of P4 against CS-induced COPD. In vitro, P4 co-treatment significantly ameliorated H2O2-induced oxidative injury and mitochondrial dysfunctions by promoting cell proliferation, increasing mitochondrial membrane potential, decreasing ROS levels and apoptosis, and increasing ATP content. Moreover, P4 co-treatment partially attenuated H2O2-caused inhibition in Nrf1, Tfam, Mfn1, PGR-B, c-MYC, SIRT1, and PGC-1α levels. In BEAS-2B and ASM cells, the c-MYC/SIRT1 axis regulated P4’s protective effects against H2O2-induced oxidative injury and mitochondrial dysfunctions.ConclusionP4 activates the c-MYC/SIRT1 axis, ameliorating CS-induced COPD and protecting both airway epithelial cells and smooth muscle cells against H2O2-induced oxidative damage. PGC-1α and downstream mitochondrial signaling pathways might be involved.

Abstract Tu142: Pannexin-2 Deficiency Exacerbates Stress-induced Cell Injury in Cardiomyocytes

Pannexins are a family of channel proteins involved in a variety of biological processes, including cell death signaling and immune functions. While Pannexin isoforms 1 and 3 have been widely studied, mainly in the brain, much less is known about the role of isoform 2 (Pannexin2, or Panx2). A recent study showed that deficiency in Panx2 sensitizes pancreatic beta cells to cytokine-induced apoptosis, while another study revealed that Panx2 promotes ultraviolet-induced apoptosis in keratinocytes. The role of Panx2 in the regulation of cardiomyocyte function has not been investigated. In the current study, we explored the subcellular distribution profile of Panx2 expression in cardiomyocytes (AC16 cells and adult cardiomyocytes) and examined the role of Panx2 in regulating cardiomyocyte response to stress. Western blotting analysis revealed palmitoylation of Panx2 in the heart, suggesting that this channel is located intracellularly, instead of in the plasma membrane. Confocal imaging revealed that Panx2 expression is in the proximity of the sarcoplasmic reticulum and mitochondria, confirming its intracellular localization. The stress test results indicated that the knockdown of Panx2 by siRNA exacerbated FCCP-reduced oxidative stress and cell injury in AC16 cells. Similarly, adult cardiomyocytes isolated from Panx2-KO mice were more vulnerable to ischemia-reperfusion injury compared with wild-type cells. Finally, we found that the level of Panx2 expression altered in the cardiac tissue of a mouse model with pressure overload-induced heart failure, implying that Panx2 may be involved in the pathological remodeling of a failing heart.

Taraxasterol protects against acetaminophen-induced hepatotoxicity by reducing liver inflammatory response and ameliorating oxidative stress in mice

Acute liver failure is mainly caused by the overdose of acetaminophen (APAP) globally. The traditional Chinese medicinal (TCM) herb, Taraxacum, contains Taraxasterol (TAX) as one of the active components. It is a pentacyclic-triterpene compound isolated from this herb. Present work aimed to investigate the in vitro and in vivo protection effect of TAX in APAP-induced acute liver injury, and determine the potential regulatory mechamisms. The liver injury caused by APAP is attenuated by TAX, as shown by the alleviated pathological changes of mice liver and the reduced serological indexes. TAX evidently controlled the oxidative stress and liver inflammation in mice liver. In vitro studies found that TAX reversed the decrease in LO2 cell viability induced by APAP, and protected LO2 cells from APAP-induced injury. In addition, TAX reduced the secretion of inflammatory factors in RAW264.7 macrophages as induced via APAP. Besides, TAX inhibited oxidative stress in LO2 cells induced by APAP in vitro. Noteworthy, TAX enhanced protein and mRNA expressions of Nrf2 in vivo, and knockdown of Nrf2 by using adeno-associated virus (AAV)-Nrf2-KO attenuated inhibitory impact of TAX in acute liver injury induced by APAP. Also, AAV-NRF2-KO weakened the inhibitory impact of TAX against APAP-triggered liver inflammation and oxidative stress of mice liver. Moreover, TAX activated the Nrf2 signaling in APAP-induced LO2 cells, as shown by the increased nuclear Nrf2 expression together with downstream HO-1 expression in vitro. Inhibition of Nrf2 by using ML-385, anNrf2inhibitor, weakened the inhibitory effect of TAX against APAP-induced oxidative stress and cell injury in LO2 cells. Moreover, inhibition of Nrf2 attenuated anti-inflammatory effect of TAX for APAP-induced RAW264.7 cells. Collectively, TAX could protect against APAP-triggered hepatotoxicitythrough suppression of liver oxidative stress and inflammatory response in mice.

Ginseng total saponin improves red blood cell oxidative stress injury by regulating tyrosine phosphorylation and glycolysis in red blood cells

BackgroundOxidative stress is the main cause of many diseases, but because of its complex pathogenic factors, there is no clear method for treating it. Ginseng total saponin (GTS) an important active ingredients in Panax ginseng C.A. Mey (PG) and has potential therapeutic ability for oxidative stress due to various causes. However, the molecular mechanism of GTS in the treating oxidative stress damage in red blood cells (RBCs) is still unclear. PurposeThis study aimed to examine the protective effect of GTS on RBCs under oxidative stress damage and to determine its potential mechanism. MethodsThe oxidative stress models of rat RBCs induced by hydrogen peroxide (H2O2) and exhaustive swimming in vivo and in vitro was used. We determined the cell morphology, oxygen carrying capacity, apoptosis, antioxidant capacity, and energy metabolism of RBCs. The effect of tyrosine phosphorylation (pTyr) of Band 3 protein on RBCs glycolysis was also examined. ResultsGTS reduced the hemolysis of RBCs induced by H2O2 at the lowest concentration. Moreover, GTS effectively improved the morphology, enhanced the oxygen carrying capacity, and increased antioxidant enzyme activity, adenosine triphosphate (ATP) levels, and adenosine triphosphatase (ATPase) activity in RBCs. GTS also promoted the expression of membrane proteins in RBCs, inhibited pTyr of Band 3 protein, and further improved glycolysis, restoring the morphological structure and physiological function of RBCs. ConclusionsThis study shows, that GTS can protect RBCs from oxidative stress damage by improving RBCs morphology and physiological function. Changes in pTyr expression and its related pTyr regulatory enzymes before and after GTS treatment suggest that Band 3 protein is the main target of GTS in the treating endogenous and exogenous oxidative stress. Moreover, GTS can enhance the glycolytic ability of RBCs by inhibiting pTyr of Band 3 protein, thereby restoring the function of RBCs.

Nicotinamide Supplementation Mitigates Oxidative Injury of Bovine Intestinal Epithelial Cells through Autophagy Modulation.

The small intestine is important to the digestion and absorption of rumen undegradable nutrients, as well as the barrier functionality and immunological responses in ruminants. Oxidative stress induces a spectrum of pathophysiological symptoms and nutritional deficits, causing various gastrointestinal ailments. Previous studies have shown that nicotinamide (NAM) has antioxidant properties, but the potential mechanism has not been elucidated. The aim of this study was to explore the effects of NAM on hydrogen peroxide (H2O2)-induced oxidative injury in bovine intestinal epithelial cells (BIECs) and its potential mechanism. The results showed that NAM increased the cell viability and total antioxidant capacity (T-AOC) and decreased the release of lactate dehydrogenase (LDH) in BIECs challenged by H2O2. The NAM exhibited increased expression of catalase, superoxide dismutase 2, and tight junction proteins. The expression of autophagy-related proteins was increased in BIECs challenged by H2O2, and NAM significantly decreased the expression of autophagy-related proteins. When an autophagy-specific inhibitor was used, the oxidative injury in BIECs was not alleviated by NAM, and the T-AOC and the release of LDH were not affected. Collectively, these results indicated that NAM could alleviate oxidative injury in BIECs by enhancing antioxidant capacity and increasing the expression of tight junction proteins, and autophagy played a crucial role in the alleviation.

Ferulic acid in synergy with retinol alleviates oxidative injury of HaCaT cells during UVB-induced photoaging.

Application of retinol (Vitamin A, VA) in skincare is limited for instability, poor water solubility, and skin intolerance that combats skin aging. We employed computer-aided virtual screening and cell experiments with transcriptomics, thereby unveiling the comprehensive gene expression and regulation pathway of photoaging HaCaT cell treated with ferulic acid (FA) in synergizing with VA. Through network pharmacology analysis, the combined use of VA and FA exhibited highly correlated cross-targets with skin aging acting on EGFR, PTPN1, ESR2, GSK3B, BACE1, PYGL, PTGS2 and APP. The indicators of oxidative stress, such as SOD, GSH, MDA, CAT and ROS in HaCaT cells after co-administration, were significantly improved from those in photoaging group (p<0.0001). 155 differential expressed genes (DEGs) were specific between groups, while reducing the expression of PTGS2 was identified as an important regulatory factor in photoaging HaCaT cells by VA and FA. Those DEGs of co-administration group focused on oxidative-reduction enzyme activity, skin growth, keratinization, and steroid biosynthesis. Apparently, the co-administration of VA and FA effectively mitigated the process of UVB-induced photoaging by reducing oxidative stress injury, inflammation responses, and regulating cell growth. This synergistic approach significantly slowed down the photoaging progression and improved the applied performance of VA in HaCaT cells.

Physio-biochemical responses of rice to smart nitrogen fertilizer nano-hydrogel under drought stress and flooding alternation: An eco-friendly innovative approach to enhance the grain quality

Fertilizer nanohydrogels have been newly introduced to agriculture. Herein, we investigated the effects of smart nitrogen (N) fertilizer nano-hydrogel on rice's physio-biochemical traits and seed quality under different drought stress and flooding conditions. Therefore, a pot experiment was conducted with no N fertilizer delivery 0 g N/kg (NND), with conventional N fertilizer delivery 0.175 g N/kg (CND), and smart N fertilizer delivery 0.175 g N/kg (SND) using three irrigation options: flooding/moderate dryness (FMD, 90% saturation, 30 mm submerged), flooding/sharp dryness (FSD, 70% saturation, 30 mm submerged), and flooding/extreme dryness (FED, 50% saturation, 30 mm submerged). Results showed that rice root's active acquisition area and enzymatic activity were larger in FMD × SND than in FED × NND, as the former combination increased NH4+, NO3−, and TN contents in the soil while the latter reduced their availability. The optimal N nutrition improved the plant cell ultrastructure, and the catalase activity was higher in the FMD × SND (42.0 µg/min) compared to the FED × NND (25.2 µg/min), leading to the alleviation of oxidative cell injury, as verified by lesser radical oxidative sequences and lipid peroxidation. The leaf soluble protein (8.8 mg/g) and sugar (36.9 mg/g) were greater in FMD × SND than in FED × NND (5.3 mg/g), (10.4 mg/g), and (8.3 µg/g h), respectively. Moreover, α-amylase and glutamine synthetase activities were larger in the FMD × SND than in FED × NND. Meanwhile, the FMD × SND resulted in the highest milled rice (87.3%), amylose (17.6%), protein (12.4%), and fatty acids (11.1%). However, the combination of FED × NND led to the lowest milled rice (70.0%), amylose (5.6%), protein (5.3%), and fatty acids (6.6%). This study suggests that the FMD × SND can guarantee physio-biochemical improvements in rice, thereby increasing grain quality.

Genetic Ablation of STE20-Type Kinase MST4 Does Not Alleviate Diet-Induced MASLD Susceptibility in Mice.

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its advanced subtype, metabolic dysfunction-associated steatohepatitis (MASH), have emerged as the most common chronic liver disease worldwide, yet there is no targeted pharmacotherapy presently available. This study aimed to investigate the possible in vivo function of STE20-type protein kinase MST4, which was earlier implicated in the regulation of hepatocellular lipotoxic milieu in vitro, in the control of the diet-induced impairment of systemic glucose and insulin homeostasis as well as MASLD susceptibility. Whole-body and liver-specific Mst4 knockout mice were generated by crossbreeding conditional Mst4fl/fl mice with mice expressing Cre recombinase under the Sox2 or Alb promoters, respectively. To replicate the environment in high-risk subjects, Mst4-/- mice and their wild-type littermates were fed a high-fat or a methionine-choline-deficient (MCD) diet. Different in vivo tests were conducted in obese mice to describe the whole-body metabolism. MASLD progression in the liver and lipotoxic damage to adipose tissue, kidney, and skeletal muscle were analyzed by histological and immunofluorescence analysis, biochemical assays, and protein and gene expression profiling. In parallel, intracellular fat storage and oxidative stress were assessed in primary mouse hepatocytes, where MST4 was silenced by small interfering RNA. We found that global MST4 depletion had no effect on body weight or composition, locomotor activity, whole-body glucose tolerance or insulin sensitivity in obese mice. Furthermore, we observed no alterations in lipotoxic injuries to the liver, adipose, kidney, or skeletal muscle tissue in high-fat diet-fed whole-body Mst4-/- vs. wild-type mice. Liver-specific Mst4-/- mice and wild-type littermates displayed a similar severity of MASLD when subjected to an MCD diet, as evidenced by equal levels of steatosis, inflammation, hepatic stellate cell activation, fibrosis, oxidative/ER stress, and apoptosis in the liver. In contrast, the in vitro silencing of MST4 effectively protected primary mouse hepatocytes against ectopic lipid accumulation and oxidative cell injury triggered by exposure to fatty acids. In summary, these results suggest that the genetic ablation of MST4 in mice does not mitigate the initiation or progression of MASLD and has no effect on systemic glucose or insulin homeostasis in the context of nutritional stress. The functional compensation for the genetic loss of MST4 by yet undefined mechanisms may contribute to the apparent discrepancy between in vivo and in vitro phenotypic consequences of MST4 silencing.

Melatonin antagonizes oxidative stress-induced apoptosis in retinal ganglion cells through activating the thioredoxin-1 pathway.

This study aimed to explore the role of melatonin in oxidative stress-induced injury on retinal ganglion cells and the underlying mechanisms. The immortalized RGC-5 cells were treated with H2O2 to induce oxidative injury. Cell viability was measured by Cell Counting Kit-8, and apoptosis was determined by flow cytometry and western blot assays. Reactive oxygen species (ROS), lactate dehydrogenase (LDH), and malondialdehyde (MDA) levels were examined to evaluate oxidative stress levels. In addition, Thioredoxin-1 (Trx1) was silenced in RGC-5 cells using small interfering RNA followed by signaling pathway examination to explore the underlying mechanisms of melatonin in alleviating oxidative injury. Melatonin pre-treatment significantly alleviated H2O2-induced apoptosis in RGC-5 cells. Melatonin also markedly reversed the upregulation of cleaved-caspase 3, cleaved-caspase 9, and Bax expression and downregulation of Bcl-2 expression induced by H2O2. Further analyses presented that melatonin significantly attenuated the increase of ROS, LDH, and MDA levels in RGC-5 cells after H2O2 treatment. Melatonin also abolished the downregulated expression of Superoxide dismutase type 1, Trx1, and Thioredoxin reductase 1, and the reduced activity of thioredoxin reductase in RGC-5 cells after H2O2 treatment. Notably, Trx1 knockdown significantly mitigated the protective effect of melatonin in alleviating H2O2-induced apoptosis and oxidative stress, while administration of compound C, a common inhibitor of c-Jun N-terminal kinase (JNK) signaling, partially reversed the effect of Trx1 silencing, thereby ameliorating the apoptosis and oxidative injury induced by H2O2 in RGC-5 cells. Melatonin could significantly alleviate oxidative stress-induced injury of retinal ganglion cells via modulating Trx1-mediated JNK signaling pathway.

Neuroprotective Potential of Thunbergia laurifolia Lindl Leaf Extracts Against Beta Amyloid-induced Neurotoxicity: An in vitroModel of Alzheimer’s Disease

Background: Beta-amyloid peptide (Aβ) induces oxidative stress, contributing to Alzheimer’s disease (AD) initiation and progression. This study aims to explore Thunbergia laurifolia ( T. laurifolia) leaf extract’s protective effects on Aβ25–35-induced oxidative stress and cell injury in SH-SY5Y cells and investigate underlying mechanisms. Materials and Methods: SH-SY5Y cells were treated with T. laurifolia leaf extract in the presence or absence of Aβ25–35. After 24 h, neuroprotective effects were assessed using cell viability and lactate dehydrogenase (LDH) assays. Caspase-3/7 activity, intracellular reactive oxygen species (ROS) levels, catalase (CAT), and superoxide dismutase (SOD) activities were measured to examine mechanisms. Total flavonoid and phenolic content assays were performed. Results: The findings showed that exposure to Aβ25–35 led to a notable rise in oxidative stress in SH-SY5Y cells, as evidenced by increased levels of ROS. Additionally, Aβ25–35 treatment increased caspase-3/7 activity and LDH release and decreased cell viability. However, T. laurifolia extract effectively suppressed ROS production, attenuated caspase-3/7 activity, and concentration-dependently reduced Aβ25–35-induced neurotoxicity. LDH release decreased, and cell viability increased. SOD and CAT activities also increased after T. laurifolia treatment. The extract had total phenolic and flavonoid contents of 178.5 ± 6.86 and 32.51 ± 1.26 mg/g, respectively. Conclusion: T. laurifolia extract demonstrated neuroprotective effects against Aβ25–35-induced injury in SH-SY5Y cells. These effects were attributed to reduced oxidative stress, elevated SOD and CAT activity, and suppressed caspase-3/7 activity. T. laurifolia extract shows potential as an alternative or therapeutic approach to AD mediated by Aβ. Nevertheless, further research is needed to elucidate the mechanism by which T. laurifolia ameliorates neuronal cell death induced by Aβ25–35.

Full-length transcriptomics study of Ustiloxins-induced hepatocyte injury

Ustiloxins is a mycotoxin produced by the metabolism of Rice false smut. Studies have shown that Ustiloxins may be toxic to animals, but there is still a lack of toxicological evidence. The liver, as the main organ for the biotransformation of foreign chemicals, may be the direct target organ of Ustiloxins toxicity. In this study, we found that cell viability decreased in a dose- and time-dependent manner when BNL CL.2 cells were treated with different concentrations of Ustiloxins (0, 5, 10, 20, 30, 40, 60, 80, 100, 150 and 200 μg/mL) for 24 and 48 h. In addition, scanning electron microscope observation showed that the cell membrane of the experimental group was damaged, with the appearance of apoptotic bodies. Moreover, the ROS and GSH levels were significantly increased in cells exposed to Ustiloxins. We analyzed the key action targets of Ustiloxins on hepatocyte injury using full-length transcriptomics. A total of 1099 differentially expressed genes were screened, of which 473 genes were up-regulated, and 626 genes were down-regulated. Besides, we also found that the expression of MCM7 and CDC45 in BNL CL.2 cells treated with Ustiloxins decreased, and the expression of CCl-2, CYP1b1, CYP4f13, and GSTM1 increased according to qRT-PCR. Ustiloxins might change CYP450 and GST-related genes, affect DNA replication and cell cycle, and lead to oxidative stress and liver cell injury.

Study of the effect of keap1 on oxidative stress in human umbilical cord mesenchymal stem cells

BackgroundHucMSCs had shown promising efficacy in treating childhood diseases, but oxidative stress induced by the poor microenvironment at the site of damage resulted in low cell survival after transplantation, thus preventing the cells from maximizing therapeutic efficacy. Therefore, this study aimed to investigate the role and mechanism of keap1 in oxidative stress injury of human umbilical cord mesenchymal stem cells (hucMSCs), and to provide theoretical support for improving the efficacy of stem cell therapy.MethodsThe hucMSCs were treated with hypoxic low-sugar-free serum (GSDH) to mimic the damaged site microenvironment after implantation. Adenoviral overexpression of keap1 gene of hucMSCs was performed in vitro, and cell proliferation ability was detected by CCK8 assay, crystal violet staining assay, and cell cycle assay. Cellular redox level was assessed by Amplex Red, MDA, and GSH/GSSG kit. Mitochondrial morphology was evaluated by mitotracker Red staining. ATP production was estimated by ATP detection kit. The mRNA and protein expression levels were tested by western blotting and RT-qPCR.ResultsGSDH treatment substantially upregulated keap1 expression. Subsequently, we found that overexpression of keap1 notably inhibited cell proliferation and caused cells to stagnate in G1 phase. At the same time, overexpression of keap1 induced the production of large amounts of H2O2 and the accumulation of MDA, but suppressed the GSH/GSSG ratio and the expression of antioxidant proteins NQO1 and SOD1, which caused oxidative stress damage. Overexpression of keap1 induced cells to produce a large number of dysfunctional mitochondria resulting in reduced ATP production. Moreover, Overexpression of keap1 significantly decreased the IKKβ protein level, while upregulating IkB mRNA levels and downregulating P50 mRNA levels.ConclusionsOverexpression of keap1 may induce oxidative stress injury in hucMSCs by down-regulating IKKβ expression and inhibiting NF-κB pathway activation. This implies the importance of keap1 in hucMSCs and it may be a potential gene for genetic modification of hucMSCs.

MiR-497-5p promoted neuronal injury in ischemic stroke by inhibiting the BDNF/TrkB/PI3K/Akt pathway.

The aim of this study was to investigate the molecular mechanism by which miR-497-5p regulates neuronal injury after ischemic stroke through the BDNF/TrkB/Akt signaling pathway. PC12 cells were used to construct a stroke injury model by oxygen-glucose deprivation/reoxygenation (OGD/R). The expression level of miR-497-5p was measured by RT-qPCR. CCK-8 kit was used to detect cell viability. Cell apoptosis and reactive oxygen species (ROS) were detected by flow cytometry. MDA and SOD detection kits were used to detect MDA content and SOD activity. A double luciferase reporter system was used to verify the targeting relationship between miR-497-5p and BDNF. The expression of BDNF, TrkB, p-TrkB, Akt and p-Akt was detected by Western blot. We have found that miR-497-5p expression was inhibited after treatment with OGD/R. Simultaneously, cell apoptosis, MDA content and ROS were upregulated, while cell viability and SOD were significantly decreased in PC12 cells. The effects of OGD/R on PC12 cells were reversed with the downregulation of miR-497-5p. A double luciferase reporter assay demonstrated that miR-497-5p negatively targets BDNF. BDNF inhibited cell apoptosis and oxidative stress injury in PC12 cells. These findings suggest that miR-497-5p aggravates neuronal injury in experimental model of ischemic stroke by inhibiting the BDNF/TrkB/PI3K/Akt signaling pathway.

Activation of the Nrf2/HO-1 axis by glutaredoxin 2 overexpression antagonizes vascular endothelial cell oxidative injury and inflammation under LPS exposure.

The online version contains supplementary material available at 10.1007/s10616-023-00606-x.