Oxidative stress regulates mitogen‑activated protein kinases and c‑Jun activation involved in heat stress and lipopolysaccharide‑induced intestinal epithelial cell apoptosis

The Effects of Zinc Oxide Nanoparticles on Antioxidation, Inflammation, Tight Junction Integrity, and Apoptosis in Heat-Stressed Bovine Intestinal Epithelial Cells In Vitro

Zinc oxide nanoparticles (nano-ZnO) have diverse applications in numerous biomedical processes. The present study explored the effects of these nanoparticles on antioxidation, inflammation, tight junction integrity, and apoptosis in heat-stressed bovine intestinal epithelial cells (BIECs). Primary BIECs that were isolated and cultured from calves either were subjected to heat stress alone (42°C for 6 h) or were simultaneously heat-stressed and treated with nano-ZnO (0.8 μg/mL). Cell viability, apoptosis, and expression of genes involved in antioxidation (Nrf2, HO-1, SOD1, and GCLM), inflammation-related genes (TLR4, NF-κB, TNF-α, IL-6, IL-8, and IL-10), intestinal barrier genes (Claudin, Occludin, and ZO-1), and apoptosis-related genes (Cyt-c, Caspase-3, and Caspase-9) were assessed to evaluate the effect of nano-ZnO on heat-stressed BIECs. The nanoparticles significantly increased cell viability and decreased the rate of apoptosis of BIECs induced by heat stress. In addition, nano-ZnO promoted the expression of antioxidant-related genes HO-1 and GCLM and anti-inflammatory cytokine gene IL-10, and inhibited the pro-inflammatory cytokine-related genes IL-6 and IL-8. The nanoparticles also enhanced expression of the Claudin and ZO-1 genes, and decreased expression of the apoptosis-related genes Cyt-c and Caspase-3. These results reveal that nano-ZnO improve the antioxidant and immune capacity of BIECs and mitigate apoptosis of intestinal epithelial cells induced by heat stress. Thus, nano-ZnO have potential for detrimental the adverse effects of heat stress in dairy cows.

Transcriptomic analysis revealed the dynamic response mechanism to acute ammonia exposure in the ivory shell, Babylonia areolata

The ivory shell (Babylonia areolata) is an economically important shellfish in tropical and subtropical regions, but its intensive culture and biological characteristic of hiding in the sandy substrate make it highly susceptible to ammonia stress. In this study, we investigated the dynamic changes in histopathology, oxidative stress, and transcriptome of the ivory shell at different time points under high concentration (60 mg/L) ammonia exposure. With prolonged exposure to stress, vacuoles appeared in the hepatopancreas while cell volume and intercellular space increased. The activities of superoxide dismutase (SOD) and catalase (CAT) decreased significantly under high concentrations of ammonia-induced stress while malondialdehyde (MDA) levels increased significantly. Integrated analysis of differentially expressed genes (DEGs), weighted gene co-expression network analysis (WGCNA), and quantitative real-time polymerase chain reaction (qRT-PCR) revealed that lipid transport primarily contributed to maintaining cellular homeostasis during the early stage of stress (6 and 12 h). Subsequently, a significant upregulation of oxidation-reduction reactions occurred at the middle stage (24 h), leading to oxidative stress. Finally, during the later stage (48 h), metabolic decomposition provided energy for survival maintenance. Additionally, lysosome and apoptosis were identified as potential key pathways in response to acute ammonia toxicity. Overall, our findings suggest that ivory shells can respond to acute ammonia toxicity via immune and antioxidant defense mechanisms but sustained high concentrations may cause irreversible damage. This study provides valuable insights into the response mechanism of mollusks towards ammonia and serves as a data reference for breeding ammonia-tolerant varieties of ivory shells.

Tea polyphenols protect bovine intestinal epithelial cells from the adverse effects of heat-stress in vitro

Heat-stress (HS) leads to impaired gut health, adversely affecting milk production of dairy cows. In the present study, we investigated the protective effects of tea polyphenols (TP) against HS-induced damage in bovine intestinal epithelial cells (BIECs) and explored the underlying mechanisms. Primary BIECs were isolated from bovine duodenum, cultured and treated as follows: (1) control cells incubated in complete medium at 37 °C for 12 h, (2) TP group incubated in medium containing 100 μg/mL TP at 37 °C for 12 h, (3) HS group incubated in medium at 37 °C for 6 h followed by 6 h at 42 °C, and (4) HS + TP group incubated with 100 μg/mL TP for 6 h at 37 °C and 6 h at 42 °C. TP improved cell viability and antioxidant capacity, and decreased apoptosis and LDH activity. TP led to upregulation of Nrf2 and its target antioxidant genes HO-1, NQO1 and SOD1 expression. TP significantly decreased the expression of proinflammatory cytokine genes (NF-κB, IL-6 and TNF-α), and increased expression of the anti-inflammatory cytokine gene, IL-10. The above results suggested that TP protected BIECs from HS-induced adverse effects by alleviating oxidative stress and inflammatory responses, indicating that TP can alleviate HS-induced intestinal damage in dairy cows.

Vitexin Regulates Heat Shock Protein Expression by Modulating ROS Levels Thereby Protecting against Heat-Stress-Induced Apoptosis

Heat stress due to high temperatures can cause heat stroke, pyrexia, heat cramps, heart disease, and respiratory diseases, which seriously affect human health. Vitexin has been shown to alleviate heat stress; however, its mechanism of action remains unclear. Therefore, in this study, we used Caco-2 cells to establish a heat stress model and vitamin C as a positive control to investigate the regulatory effects of vitexin on heat-stress-induced apoptosis and the related mechanisms using Cell Counting Kit-8, flow cytometry, real-time quantitative polymerase chain reaction, and Western blot. The results showed that the mRNA expressions of Hsp27, Hsp70, and Hsp90 induced by heat stress could be effectively inhibited at vitexin concentrations as low as 30 μM. After heat stress prevention and heat stress amelioration in model cells based on this concentration, intracellular reactive oxygen species (ROS) levels and the mRNA level and the protein expression of heat shock proteins (Hsp70 and Hsp90) and apoptotic proteins were reduced. In addition, compared with the heat stress amelioration group, the expression of BCL2 mRNA and its protein (anti-apoptotic protein Bcl-2) increased in the heat stress prevention group, while the expression of BAX, CYCS, CASP3, and PARP1 mRNAs and their proteins (apoptotic proteins Bax, Cytochrome C, cle-Caspase-3, and cle-PARP1) were decreased. In summary, the heat-stress-preventive effect of vitexin was slightly better than its heat-stress-ameliorating effect, and its mechanism may be through the inhibition of intracellular ROS levels and thus the modulation of the expressions of Hsp70 and Hsp90, which in turn protects against heat-stress-induced apoptosis. This study provides a theoretical basis for the prevention and amelioration of heat stress using vitexin.

c-Jun N-terminal kinase activation contributes to improving low temperature tolerance via regulating apoptosis in the Pacific white shrimp Penaeus vannamei

Temperature is an essential environmental factor for the survival of aquatic animals. Low temperature stress can induce mitochondria to produce excessive ROS and free radicals, and destroy homeostasis. c-Jun N-terminal kinase (JNK) is involved in regulating various physiological processes, including inflammatory responses, cell cycle, reproduction, and apoptosis. Here, we investigated the mechanism of ROS/JNK pathway under low temperature stress both in vitro and in vivo. In this study, transcriptome analysis revealed that apoptosis, autophagy, calcium channel, and antioxidant were involved in the mediation of low temperature tolerance in Pacific white shrimp (penaeus vannamei). PvJNK was activated in response to low temperature stress. Treatments with different temperature caused oxidative stress as demonstrated by increased intensity of the ROS indicator H2DCF-DA, and induced apoptosis as confirmed by indicator FITC. Pretreatment with N-acetylcysteine, an ROS scavenger, attenuated low temperature induced apoptosis, and inhibited the expression of PvJNK. In addition, we demonstrate that mediator PvJNK translocated to nuclear through interacting with PvRheb. By using flow cytometry, inhibiting PvJNK can increase the expression of apoptosis related genes, accelerate tissue damage, and induce ROS and cell apoptosis. The ultimate inhibition of PvJNK accelerates the mortality of shrimp under low temperature stress. Overall, these findings suggest that during low temperature stress, PvJNK was activated by ROS to regulates apoptosis via interacting with PvRheb to promote PvJNK into the nucleus and to improve low temperature tolerance of shrimp.

The pathogenesis and therapeutic strategies of heat stroke-induced liver injury

Heat stroke (HS) is a life-threatening systemic disease characterized by an elevated core body temperature of more than 40 ℃ and subsequent multiple organ dysfunction syndrome. With the growing frequency of global heatwaves, the incidence rate of HS has increased significantly, which has caused a huge burden on people's lives and health. Liver injury is a well-documented complication of HS and usually constitutes the direct cause of patient death. In recent years, a lot of research has been carried out on the pathogenesis and treatment strategies of HS-induced liver injury. In this review, we summarized the important pathogenesis of HS-induced liver injury that has been confirmed so far. In addition to the comprehensive effect of systemic factors such as heat cytotoxicity, coagulopathy, and systemic inflammatory response syndrome, excessive hepatocyte cell pyroptosis, dysfunction of Kupffer cells, abnormal expression of heat shock protein expression, and other factors are also involved in the pathogenesis of HS-induced liver injury. Furthermore, we have also established the current therapeutic strategies for HS-induced liver injury. Our study is of great significance in promoting the understanding of the pathogenesis and treatment of HS-induced liver injury.

2-O-β-d-Glucopyranosyl-4,6-dihydroxybenzaldehyde Isolated from Morus alba (Mulberry) Fruits Suppresses Damage by Regulating Oxidative and Inflammatory Responses in TNF-α-Induced Human Dermal Fibroblasts

Human skin is composed of three layers, of which the dermis is composed of an extracellular matrix (ECM) comprising collagen, elastin, and other proteins. These proteins are reduced due to skin aging caused by intrinsic and extrinsic factors. Among various internal and external factors related to aging, ultraviolet (UV) radiation is the main cause of photoaging of the skin. UV radiation stimulates DNA damage, reactive oxygen species (ROS) generation, and pro-inflammatory cytokine production such as tumor necrosis factor-alpha (TNF-α), and promotes ECM degradation. Stimulation with ROS and TNF-α upregulates mitogen-activated protein kinases (MAPKs), nuclear factor kappa B (NF-κB), and activator protein 1 (AP-1) transcription factors that induce the expression of the collagenase matrix metalloproteinase-1 (MMP-1). Moreover, TNF-α induces intracellular ROS production and several molecular pathways. Skin aging progresses through various processes and can be prevented through ROS generation and TNF-α inhibition. In our previous study, 2-O-β-d-glucopyranosyl-4,6-dihydroxybenzaldehyde (GDHBA) was isolated from the Morus alba (mulberry) fruits and its inhibitory effect on MMP-1 secretion was revealed. In this study, we focused on the effect of GDHBA on TNF-α-induced human dermal fibroblasts (HDFs). GDHBA (50 μM) inhibited ROS generation (18.8%) and decreased NO (58.4%) and PGE₂ levels (53.8%), significantly. Moreover, it decreased MMP-1 secretion (55.3%) and increased pro-collagen type I secretion (207.7%). GDHBA (50 μM) decreased the expression of different MAPKs as per western blotting; p-38: 35.9%; ERK: 47.9%; JNK: 49.5%; c-Jun: 32.1%; NF-κB: 55.9%; and cyclooxygenase-2 (COX-2): 31%. This study elucidated a novel role of GDHBA in protecting against skin inflammation and damage through external stimuli, such as UV radiation.

Multiple Mechanistic Action of Brevinin-1FL Peptide against Oxidative Stress Effects in an Acute Inflammatory Model of Carrageenan-Induced Damage

Amphibian skin is acknowledged to contain an antioxidant system composed of various gene-encoded antioxidant peptides, which exert significant effects on host defense. Nevertheless, recognition of such peptides is in its infancy so far. Here, we reported the antioxidant properties and underlying mechanism of a new antioxidant peptide, brevinin-1FL, identified from Fejervarya limnocharis frog skin. The cDNA sequence encoding brevinin-1FL was successfully cloned from the total cDNA of F. limnocharis and showed to contain 222 bp. The deduced mature peptide sequence of brevinin-1FL was FWERCSRWLLN. Functional analysis revealed that brevinin-1FL could concentration-dependently scavenge ABTS⁺, DPPH, NO, and hydroxyl radicals and alleviate iron oxidation. Besides, brevinin-1FL was found to show neuroprotective activity by reducing contents of MDA and ROS plus mitochondrial membrane potential, increasing endogenous antioxidant enzyme activity, and suppressing H₂O₂-induced death, apoptosis, and cycle arrest in PC12 cells which were associated with its regulation of AKT/MAPK/NF-κB signal pathways. Moreover, brevinin-1FL relieved paw edema, decreased the levels of TNF-α, IL-1β, IL-6, MPO, and malondialdehyde (MDA), and restored catalase (CAT) and superoxide dismutase (SOD) activity plus glutathione (GSH) contents in the mouse injected by carrageenan. Together, these findings indicate that brevinin-1FL as an antioxidant has potent therapeutic potential for the diseases induced by oxidative damage. Meanwhile, this study will help us further comprehend the biological functions of amphibian skin and the mechanism by which antioxidants protect cells from oxidative stress.

The Characteristics of Organ Function Damage of Hemorrhagic Shock in Hot Environment and the Effect of Hypothermic Fluid Resuscitation

BACKGROUND

Hemorrhagic shock is the important factor for causing death of trauma and war injuries. However, pathophysiological characteristics and underlying mechanism in hemorrhagic shock with hot environment remain unclear.

METHODS

Hemorrhagic shock in hot environment rat model was used to explore the changes of mitochondrial and vital organ functions, the variation of the internal environment, stress factors, and inflammatory factors; meanwhile, the suitable treatment was further studied.

RESULTS

Above 36°C hot environment induced the increase of core temperature of rats, and the core temperature was not increased in 34°C hot environment, but the 34°C hot environment aggravated significantly hemorrhagic shock induced mortality. Further study showed that the mitochondrial functions of heart, liver, and kidney were more damaged in hemorrhagic shock rats with 34°C hot environment as compared with room environment. Moreover, the results showed that in hemorrhagic shock rats with hot environment, the blood concentration of Na+, K+, and plasma osmotic pressure, the expression of inflammatory factors tumor necrosis factor-α and interleukin-6 in the serum, as well as the stress factors Adrenocorticotropic Hormone and Glucocorticoid were all notably enhanced; and acidosis was more serous; oxygen supply and oxygen consumption were remarkably decreased. In addition, the present study demonstrated that mild hypothermia (10°C) fluid resuscitation could significantly improve the survival rate in hemorrhagic shock rats with hot environment as compared with normal temperature fluid resuscitation.

CONCLUSIONS

Hot environment accelerated the death of hemorrhagic shock rats, which was related to the disorder of internal environment, the increase of inflammatory and stress factors. Furthermore, moderate hypothermic (10°C) fluid resuscitation was suitable for the treatment of hemorrhagic shock in hot environment.

Sheng Mai San ameliorated heat stress-induced liver injury via regulating energy metabolism and AMPK/Drp1-dependent autophagy process

BACKGROUND

Liver damage is one of the most common complications in humans and animals after heat stress (HS). Sheng Mai San (SMS), a traditional Chinese medicine prescription that originated in the Jin Dynasty, exert a therapeutic effect on HS. However, how SMS prevents liver injury after heat exposure remains unknown.

PURPOSE

This study aimed to investigate the pharmacological effect and molecular mechanisms of SMS on HS-induced liver injury.

STUDY DESIGN

A comprehensive strategy via incorporating pharmacodynamics, targeted metabolomics, and molecular biology technology was adopted to investigate energy metabolism changes and the therapeutic mechanisms of SMS in HS-induced rat liver injury.

METHODS

First, Sprague-Dawley rats were subjected to HS (38 °C/ 75% RH/ 2 h/ day) for 7 consecutive days to establish the HS model, and SMS was given orally for treatment 2 h before heat exposure. Thereafter, liver function and pathological changes in liver tissue were evaluated. Finally, the underlying mechanisms of SMS were determined using targeted energy metabolomics to comprehensively analyze the metabolic pathways and were further verified through Western-blot and qRT-PCR assays.

RESULTS

Our results showed that SMS alleviated HS-induced liver dysfunction by reducing the alanine aminotransferase (ALT), aspartate aminotransferase (AST), and AST/ALT ratios in serum and improving hepatic pathological damage. Meanwhile, SMS suppressed inflammatory response, oxidative injury, and overexpression of heat shock proteins in liver tissue after heat exposure. With the help of targeted energy metabolomics, we found that SMS could effectively regulate glycolysis and tricarboxylic acid (TCA) cycle to relieve energy metabolism disorder. Furthermore, we confirmed that SMS can facilitate the phosphorylation of AMP-activated protein kinase (AMPK) to maintain mitochondrial homeostasis through a dynamin protein 1 (Drp1)-dependent mitophagy process.

CONCLUSION

On the basis of energy metabolomics, the present study for the first time systematically illustrated the protective effect of SMS on HS-induced liver injury, and preliminarily confirmed that an AMPK-mediated Drp1-dependent mitophagy and mitochondria rebuilding process plays an important role in SMS intervention on HS-induced rat liver. Together, our study lends further support to the use of SMS in treating HS condition.

Oxidative Stress Induces a Breakdown of the Cytoskeleton and Tight Junctions of the Corneal Endothelial Cells

Purpose: To investigate the impact of oxidative stress, which is a hallmark of Fuchs dystrophy, on the barrier function of the corneal endothelial cells. Methods: Experiments were carried out with cultured bovine and porcine corneal endothelial cells. For oxidative stress, cells were supplemented with riboflavin (Rf) and exposed to UV-A (15-30 min) to induce Type-1 photochemical reactions that release H₂O₂. The effect of the stress on the barrier function was assayed by transendothelial electrical resistance (TER) measurement. In addition, the associated changes in the organization of the microtubules, perijunctional actomyosin ring (PAMR), and ZO-1 were evaluated by immunocytochemistry, which was also repeated after direct exposure to H₂O₂ (100 μM, 1 h). Results: Exposure to H₂O₂ led to the disassembly of microtubules and the destruction of PAMR. In parallel, the contiguous locus of ZO-1 was disrupted, marking a loss of barrier integrity. Accordingly, a sustained loss in TER was induced when cells in the Rf-supplemented medium were exposed to UV-A. However, the addition of catalase (7,000 U/mL) to rapidly decompose H₂O₂ limited the loss in TER. Furthermore, the adverse effects on microtubules, PAMR, and ZO-1 were suppressed by including catalase, ascorbic acid (1 mM; 30 min), or pretreatment with p38 MAP kinase inhibitor (SB-203580; 10 μM, 1 h). Conclusions: Acute oxidative stress induces microtubule disassembly by a p38 MAP kinase-dependent mechanism, leading to the destruction of PAMR and loss of barrier function. The response to oxidative stress is reminiscent of the (TNF-α)-induced breakdown of barrier failure in the corneal endothelium.

Heat Stress-Mediated Activation of Immune-Inflammatory Pathways

Physiological changes in animals exposed to elevated ambient temperature are characterized by the redistribution of blood toward the periphery to dissipate heat, with a consequent decline in blood flow and oxygen and nutrient supply to splanchnic tissues. Metabolic adaptations and gut dysfunction lead to oxidative stress, translocation of lumen contents, and release of proinflammatory mediators, activating a systemic inflammatory response. This review discusses the activation and development of the inflammatory response in heat-stressed models.

Aromatic hydrocarbon receptors in mitochondrial biogenesis and function

Mitochondria are ubiquitous membrane-bound organelles that not only play a key role in maintaining cellular energy homeostasis and metabolism but also in signaling and apoptosis. Aryl hydrocarbons receptors (AhRs) are ligand-activated transcription factors that recognize a wide variety of xenobiotics, including polyaromatic hydrocarbons and dioxins, and activate diverse detoxification pathways. These receptors are also activated by natural dietary compounds and endogenous metabolites. In addition, AhRs can modulate the expression of a diverse array of genes related to mitochondrial biogenesis and function. The aim of the present review is to analyze scientific data available on the AhR signaling pathway and its interaction with the intracellular signaling pathways involved in mitochondrial functions, especially those related to cell cycle progression and apoptosis. Various evidence have reported the crosstalk between the AhR signaling pathway and the nuclear factor κB (NF-κB), tyrosine kinase receptor signaling and mitogen-activated protein kinases (MAPKs). The AhR signaling pathway seems to promote cell cycle progression in the absence of exogenous ligands, whereas the presence of exogenous ligands induces cell cycle arrest. However, its effects on apoptosis are controversial since activation or overexpression of AhR has been observed to induce or inhibit apoptosis depending on the cell type. Regarding the mitochondria, although activation by endogenous ligands is related to mitochondrial dysfunction, the effects of endogenous ligands are not well understood but point towards antiapoptotic effects and inducers of mitochondrial biogenesis.

Insulin resistance is independently associated with cardiovascular autonomic neuropathy in type 2 diabetes

AIMS/INTRODUCTION

Diabetic cardiovascular autonomic neuropathy (DCAN) seriously threatens the prognosis and quality of life of patients with type 2 diabetes mellitus, associated with increased mortality. The present study aimed to investigate the relevant risk factors of DCAN.

MATERIALS AND METHODS

The present study enrolled a total of 109 patients with type 2 diabetes mellitus. DCAN was defined as a score of at least 2 points in Ewing tests. The updated homeostasis model assessment of insulin resistance (HOMA2-IR) based on fasting C-peptide was calculated to reflect insulin resistance. Logistic regression analysis, interaction and stratified analyses were used to investigate the relationship between HOMA2-IR or other indicators and DCAN. Receiver operating characteristic analysis was carried out to estimate the discriminative value of the variables independently associated with DCAN and to determine the optimal cut-off point of these models to screen DCAN.

RESULTS

The HOMA2-IR levels were significantly higher in patients with DCAN, and tended to be worsened with the progression of the DCAN. Logistic regression analysis showed an independent association between HOMA2-IR (odds ratio 39.30, 95% confidence interval 7.17-215.47) and DCAN. HOMA2-IR (area under the curve 0.878, 95% confidence interval 0.810-0.946; cut-off value 1.735) individually predicted DCAN significantly higher than the other independent risk factors individually used, whereas models combining HOMA2-IR and other risk factors did not significantly boost the diagnostic power.

CONCLUSIONS

Insulin resistance is independently associated with DCAN. HOMA2-IR presents to be a highly accurate and parsimonious indicator for DCAN screening. Patients with HOMA2-IR >1.735 are at a high risk of DCAN; thus, priority diagnostic tests should be carried out for these patients for timely integrated intervention.

miR‑3613‑3p/MAP3K2/p38/caspase‑3 pathway regulates the heat‑stress‑induced apoptosis of endothelial cells

Previous studies have identified microRNA (miRNA/miR)-3613-3p as a heat stress (HS)-related miRNA in endothelial cells that can lead to apoptosis. However, the mechanism underlying the miR-3613-3p-mediated apoptosis of HS-exposed endothelial cells remains unclear. In the present study, western blot analysis and reverse transcription-quantitative PCR were used to determine protein and miRNA expression levels, respectively. Annexin V-fluorescein isothiocyanate/propidium iodide staining, caspase-3 activity measurements and DNA fragmentation assays were performed to detect apoptosis. To evaluate whether mitogen-activated protein kinase kinase kinase 2 (MAP3K2) was a direct target of miR-3613-3p, a luciferase reporter assay was performed. In addition, transient transfection was used to carry out loss- and gain-of-function experiments. The results revealed that miR-3613-3p expression was reduced in human umbilical vein endothelial cells (HUVECs) following HS, which led to apoptosis. Mechanistically, following HS, a decrease in miR-3613-3p binding to the 3′-untranslated region of MAP3K2 directly upregulated its expression, and the downstream p38 and caspase-3 pathways, thereby leading to apoptosis. Taken together, the results of the present study demonstrated that HS suppressed miR-3613-3p expression, which activated the MAP3K2/p38/caspase-3 pathway, leading to the apoptosis of HUVECs. In conclusion, the miR-3613-3p/MAP3K2/p38/caspase-3 pathway may serve an indispensable role in regulating the progression of apoptosis, indicating a regulatory role of miR-3613-3p in the pathophysiology of HS-exposed endothelial cells.

The Protective Effects of Orthosiphon stamineus Extract Against Intestinal Barrier Injury in High-Fat Diet-Induced Mouse and Oxidative Stress Cell Models

Orthosiphon stamineus Benth. (Lamiaceae) is commonly used for the treatment of kidney diseases, but its role in intestinal barrier function remains unknown. The present study investigated the protective effects of O. stamineus extract (OE) against oxidative stress-induced injury to the small intestinal epithelium and the possible mechanism. High-performance liquid chromatography fingerprinting was used to analyze OE. Oxidative stress was induced by hydrogen peroxide (1 mM for 1 hour) in an IPEC-J2 cell monolayer model and a high-fat diet in C57BL/6 mice (8 weeks). The malondialdehyde (MDA) content was tested in both models. To evaluate permeability, transepithelial electrical resistance (TEER) was tested in a cell model. Serum diamine oxidase (DAO) and endotoxin contents were determined in a mouse model, and histological sections were analyzed. The messenger ribonucleic acid expression of tight junction proteins was measured by quantitative real-time polymerase chain reaction. Pretreatment with OE (50 µg/mL) increased the IPEC-J2 cell monolayer TEER (12.4%) and decreased MDA (from 6.1 to 4.7 mmol/mg prot). Oral administration of OE (100 mg/kg) decreased serum DAO (34.2%), endotoxin (13.4%), and MDA (from 21.3 to 11.0 mmol/mL) in mice. OE upregulated ZO-1 (42.8% in the cell model and 125.0% in mice) and occluding (127.0% in the cell model and 120.3% in mice) gene expression. These results confirmed the protective effect of OE on the intestinal barrier, which was associated with the antioxidant effect of OE; thus, OE is suitable for the prevention and treatment of intestinal barrier injury.

Cerium oxide nanoparticles protect red blood cells from hyperthermia-induced damages

Heat stroke and severe fever cause anemia, although the underlying mechanism remains unclear. Here, we report the use of Cerium oxide nanoparticles in protection of red blood cells against damage caused by exposure to short-term hyperthermia (42°C, 10 min). Red blood cells exposed to hyperthermia exhibited extradition senescence with higher density, smaller size and lower zeta potential relative to those under normal physiological environment (37°C, 10 min). Furthermore, hyperthermia-exposed cells exhibited significantly higher reactive oxygen species (ROS) production compared to the normal conditions. Importantly, the preconditional treatment, using Ceria nanoparticles (CNPs), ameliorated senescence and apoptosis in red blood cells damaged by hyperthermia by reducing ROS levels. Summarily, short-term hyperthermia caused a significant increase in ROS in red blood cells, and resulted in senescence and apoptosis. These may be possible mechanisms of pathological changes in red blood cells exposed to heat stroke or severe fever. Overall, these findings indicate that CNPs strongly inhibit ROS production, and effectively ameliorates hyperthermia-induced damages in red blood cells.

Altered expression of AKT1 and P38A in the colons of patients with Hirschsprung's disease

PURPOSE

Hirschsprung's disease (HSCR) is a functional obstruction of the gastrointestinal tract due to the congenital absence of enteric ganglion cells. The proto-oncogene RET is one of the primary genes implicated in the aetiology of HSCR. We designed this study to investigate the expression of 10 RET regulatory network genes in the colons of patients with HSCR.

METHODS

HSCR tissue specimens (n = 28) were collected at the time of pull-through surgery. qPCR analysis was applied to compare the expression levels of 10 genes in the RET regulatory network. Western blot analysis was performed to quantify the protein expression. Immunohistochemistry was performed to determine the localization of AKT1 and P38A in HSCR colon tissue.

RESULTS

AKT1 (p = 0.015) and P38A (p = 0.039) were both significantly downregulated in the aganglionic segment compared to those in the ganglionic segment in HSCR patients (n = 28). Western blot analysis revealed the decreasing protein expression of AKT1 and P38A in the aganglionic segment compared to ganglionic segment and control colon tissues (p < 0.05). Immunohistochemistry staining revealed that both AKT1 and P38A were localized in the colonic mucosa and were significantly decreased in the aganglionic segment.

CONCLUSION

To our knowledge, we report for the first time the expression of RET regulatory network genes in the colons of patients with HSCR. The markedly decreased expression of AKT1 and P38A suggested a possible role in HSCR pathogenesis.

The Increase in IL-1β in the Early Stage of Heatstroke Might Be Caused by Splenic Lymphocyte Pyroptosis Induced by mtROS-Mediated Activation of the NLRP3 Inflammasome

Interleukin-1β (IL-1β) is important for the pathological process of heatstroke (HS), although little is known regarding the main source of the IL-1β produced during the early stage of HS. In this study, heat stress led splenic lymphocytes to death with generation of inflammatory cytokines. The same phenomenon also occurs in animal models of heatshock. We observed that the death of splenic lymphocytes was identified to be pyroptosis. In addition, splenic lymphocyte pyroptosis can be induced by hyperpyrexia in a time- and temperature-dependent manner with NLR pyrin domain containing 3 (NLRP3) inflammasome activation. An NLRP3 inhibitor (MCC950) and a caspase-1 inhibitor (ac-YVAD-cmk) were used to confirm the role of the NLRP3/caspase-1 pathway in pyroptosis. With heat stress, levels of mitochondrial reactive oxygen species (mtROS) in splenic lymphocytes would significantly increase. Accordingly, the use of mtROS scavenger (Mito-TEMPO) could reduce the occurrence of pyroptosis and the activation of the NLRP3 inflammasome in vitro. In animal models of heatshock, Mito-TEMPO can inhibit activation of the NLRP3/caspase-1 pathway. Taken together, our data suggest that activation of the NLRP3 inflammasome mediates hyperpyrexia-induced pyroptosis in splenic lymphocytes. Perhaps one of the important initiators of pyroptosis is mtROS. Our data have elucidated a new molecular mechanism of IL-1β overexpression in the early stage of HS, providing a new strategy for IL-1β-targeted therapy in future clinical treatments for HS.

AVE 0991 Attenuates Pyroptosis and Liver Damage after Heatstroke by Inhibiting the ROS-NLRP3 Inflammatory Signalling Pathway

We previously demonstrated that angiotensin-(1-7) (Ang-(1-7)), an essential endocrine factor, inhibits the NLRP3 inflammasome by regulating reactive oxygen species (ROS) in fibrotic livers. We also demonstrated that the NLRP3 inflammasome contributes to the liver damage induced by pyroptosis after heatstroke. However, the role of Ang-(1-7) in the hepatocytes under heat stress remains uncertain. We aimed to examine the change in angiotensin peptides in the livers affected by heatstroke and the effect on the ROS-NLRP3 inflammatory signalling pathway. In vivo, increased angiotensin II (Ang II) and decreased Ang-(1-7) in the serum of heatstroke patients suffering from hepatic dysfunction were observed. The change in angiotensin peptides was considered a potential biomarker that could be used to predict hepatic dysfunction. Enhanced Ang II and attenuated Ang-(1-7) levels were also observed in the liver tissue of heatstroke rats, which were consistent with their receptors and converting enzymes. Hepatic damage associated with increased ROS and protein expression levels of NOX4, NLRP3, caspase-1, and IL-1β was attenuated by AVE 0991, an analogue of Ang-(1-7). In vitro, pyroptosis, characterized by activated caspase-1 and IL-1β, was observed in hepatocytes under heat stress, which was enhanced by Ang II and attenuated by antioxidants, NOX4 siRNA, and AVE 0991. In summary, AVE 0991 attenuates pyroptosis and liver damage induced by heat stress by inhibiting the ROS-NLRP3 inflammatory signalling pathway.

Protective effects of mannan/β-glucans from yeast cell wall on the deoxyniyalenol-induced oxidative stress and autophagy in IPEC-J2 cells

The aim of this study was to investigate the effects of biomacromolecules mannan/β-glucans from yeast cell wall (BYCW) to alleviate Deoxynivalenol(DON)-induced injury. Considering that DON has strong oxidizing effect and stimulates autophagy and apoptosis, we examined the effects of BYCW on consequent oxidative stress damage indicators, cells autophagy and apoptosis induced by DON using the porcine jejunum epithelial cell lines (IPEC-J2) as a cell culture model. The results showed that application of BYCW could reverse the decrease of cell viability by DON significantly, and suppress the levels of tumor necrosis factor-α (TNF-α) and interleukin-8 and -6 (IL-8 and IL-6), except IL-1β. Further experiments revealed that BYCW treatment counteracted the DON-induced down-regulation of intracellular glutathione (GSH) and up-regulation of reactive oxygen species (ROS) and malondialdehyde (MDA). Through western blot analysis, we observed that BYCW treatment was able to down-regulate the expression of autophagy protein LC3-II and up-regulate the expression of P62 protein against DON, which suggested that autophagy induced by DON may be suppressed. Altogether, these results indicated a potential ability of supplementation of BYCW to improve cell growth and metabolism as well as the preventive properties of BYCW against the DON-induced cell damage by activating antioxidant system.

Resistance mechanisms and reprogramming of microorganisms for efficient biorefinery under multiple environmental stresses

In the fermentation process of biorefinery, industrial strains are normally subjected to adverse environmental stresses, which leads to their slow growth, yield decline, a substantial increase in energy consumption, and other negative consequences, which ultimately seriously hamper the development of biorefinery. How to minimize the impact of stress on microorganisms is of great significance. This review not only reveals the damaging effects of different environmental stresses on microbial strains but also introduces commonly used strategies to improve microbial tolerance, including adaptive evolution, reprogramming of the industrial host based on genetic circuits, global transcription machinery engineering (gTME) and bioprocess integration. Furthermore, by integrating the advantages of these strategies and reducing the cost of system operation, the tolerance of industrial strains, combined with production efficiency and process stability, will be greatly improved, and the development prospects of biorefinery will be more widespread.

The development of antioxidant system in the intestinal tract of broiler chickens

The gastrointestinal tract is the site for the uptake of nutrients from the external environment. We hypothesized that the antioxidant system in the intestinal tract has a vital protective role from the oxidative damage induced by oxidants in foods. The aim of this study was to investigate the development of the antioxidant system in the intestine of chickens. The activity and gene expression of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and the content of the non-enzymatic substance glutathione (GSH) were measured in the duodenum, jejunum, and ileum of chickens at 1, 3, 7, 11, 14, 21, 35, and 42 d of age. The results showed that the small intestinal tract had relatively higher SOD activity and GSH concentration and lower CAT and GSH-Px activities, compared with those of other visceral organs. CAT and GSH-Px activities and GSH concentration showed a decreasing trend with age, whereas SOD activity was not significantly influenced by age. The gene expression of SOD1, SOD2, and GSH-Px7 showed a dramatic decrease from 3 d of age. The results indicated that SOD and GSH were highly expressed in the first week of age after hatching. To conclude, the results suggest that SOD and GSH play a vital protective role in the small intestine after hatching, which contributes to rapid development of the intestine.

Electroacupuncture Alleviated Neuronal Apoptosis Following Ischemic Stroke in Rats via Midkine and ERK/JNK/p38 Signaling Pathway

This study aimed to evaluate the effects of electroacupuncture (EA) intervention administered at rats of middle cerebral artery occlusion (MCAO)/reperfusion. Fifty-four male Sprague-Dawley rats were divided into three groups, consisting of sham group, MCAO/R group, and EA group. EA treatment at Quchi and Zusanli acupoints was applied in rats of EA group at 24 h after MCAO once per day for 3 days. Our results indicated that EA treatment reduced infarct volumes and neurological deficits, as well alleviated the apoptotic cells in peri-infarct cortex, indicating that EA exerted neuroprotective effect in cerebral ischemic rats. Moreover, EA treatment may effectively reverse the upregulation of caspase-3 and Bim and alleviate the inhibition of Bcl-2 following 72-h ischemic stroke. EA may significantly reverse the promoted relative density level of p-ERK1/2, p-JNK, and p-p38 in the EA group compared with the MCAO/R group. In addition, the growth factor midkine (MK) was upregulated at 72 h after MCAO/R, and EA treatment may significantly prompt expression of MK. Our study demonstrated that EA exerted neuroprotective effect against neuronal apoptosis and the mechanism might involve in upregulation of MK and mediation of ERK/JNK/p38 signal pathway.

Long non‑coding RNA BC168687 small interfering RNA reduces high glucose and high free fatty acid‑induced expression of P2X7 receptors in satellite glial cells

Purinergic signaling contributes to inflammatory and immune responses. The activation of the P2X purinoceptor 7 (P2X₇) in satellite glial cells (SGCs) may be an essential component in the promotion of inflammation and neuropathic pain. Long non-coding RNAs (lncRNAs) are involved in multiple physiological and pathological processes. The aim of the present study was to investigate the effects of a small interfering RNA for the lncRNA BC168687 on SGC P2X₇ expression in a high glucose and high free fatty acids (HGHF) environment. It was demonstrated that BC168687 small interfering (si)RNA downregulated the co-expression of the P2X₇ and glial fibrillary acidic protein and P2X₇ mRNA expression. Additionally, HGHF may activate the mitogen-activated protein kinase signaling pathway by increasing the release of nitric oxide and reactive oxygen species in SGCs. Taken together, these results indicate that silencing BC168687 expression may downregulate the increased expression of P2X₇ receptors in SGCs induced by a HGHF environment.