Lactate Dehydrogenase Release Research Articles

Analysis of Gingival Fibroblasts Behaviour in the Presence of 3D-Printed versus Milled Methacrylate-Based Dental Resins—Do We Have a Winner?

Computer-aided design and computer-aided manufacturing (CAD/CAM) techniques are based on either subtractive (milling prefabricated blocks) or additive (3D printing) methods, and both are used for obtaining dentistry materials. Our in vitro study aimed to investigate the behavior of human gingival fibroblasts exposed to methacrylate (MA)-based CAD/CAM milled samples in comparison with that of MA-based 3D-printed samples to better elucidate the mechanisms of cell adaptability and survival. The proliferation of human gingival fibroblasts was measured after 2 and 24 h of incubation in the presence of these samples using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the membrane integrity was assessed through the lactate dehydrogenase release. The level of reactive oxygen species, expression of autophagy-related protein LC3B-I, and detection of GSH and caspase 3/7 were evaluated by fluorescence staining. The MMP-2 levels were measured using a Milliplex MAP kit. The incubation with MA-based 3D-printed samples significantly reduced the viability, by 16% and 28% from control after 2 and 24 h, respectively. There was a 25% and 55% decrease in the GSH level from control after 24 h of incubation with the CAD/CAM milled and 3D-printed samples, respectively. In addition, higher levels of LC3B-I and MMP-2 were obtained after 24 h of incubation with the MA-based 3D samples compared to the CAD/CAM milled ones. Therefore, our results outline that the MA-CAD/CAM milled samples displayed good biocompatibility during 24-h exposure, while MA-3D resins are proper for short-term utilization (less than 24 h).

The protective effects of Chromofungin in oligomeric amyloid β42 (Aβ42)-induced toxicity in neurons in Alzheimer's disease.

Oligomeric Aβ42 is considered to play a harmful role in the pathophysiology of Alzheimer's disease (AD). Prolonged exposure to oligomeric Aβ42 could induce neuronal damage including cellular senescence. Amelioration of Aβ42-induced cellular senescence has been considered as a promising strategy for the treatment of AD. Chromofungin, a chromogranin A-derived peptide, has displayed various biological functions in different types of cells and tissues. However, the effects of Chromofungin on oligomeric Aβ42-induced cellular senescence have not been previously reported. In the current study, we report a novel function of Chromofungin by showing that treatment with Chromofungin could ameliorate Aβ42-induced neurotoxicity in M17 neuronal cells. The Cell Counting Kit-8 (CCK-8) assay and the lactate dehydrogenase (LDH) release experiments revealed that 0.5 and 1 mM are the optimal concentrations of Chromofungin for cell culture in M17 cells. Challenging with oligomeric Aβ42 (5 μM) for 7 and 14 days led to a significant decrease in telomerase activity, which was rescued by Chromofungin dose-dependently. Additionally, the senescence-associated β-galactosidase (SA-β-gal) staining assay demonstrated that Chromofungin mitigated oligomeric Aβ42-induced cellular senescence. Correspondingly, treatment with Chromofungin reversed the gene expression of human telomerase reverse transcriptase (hTERT), telomeric repeat-binding factor 2 (TERF2), and p21 against oligomeric Aβ42 in M17 neurons. Interestingly, Chromofungin attenuated oligomeric Aβ42-induced oxidative stress (OS) in M17 cells by reducing the production of intracellular reactive oxygen species (ROS) but increasing the levels of intracellular superoxide dismutase (SOD). Importantly, the presence of Chromofungin reduced the expression of cyclooxygenase2 (COX-2) as well as the generation of prostaglandin E2 (PGE2). Transduction with Ad-COX-2 impaired the effects of Chromofungin on telomerase activity and the profile of cellular senescence. Our findings suggest that Chromofungin might act as a potential agent for the treatment of AD.

Locusta migratoria hydrolysates attenuate lipopolysaccharide (LPS)/D-Galactosamine (D-Gal)-induced cytotoxicity and inflammation in Hep G2 cells via NF-κB signaling suppression

The prolonged state of hepatic inflammation can lead to liver damage, a critical driving force in the progression of liver-related diseases. Locusta migratoria (LM), an edible insect, is recognized for its protein richness and potential to produce a range of bioactive polypeptides, presenting a novel solution for liver disease. This study investigated the hepatoprotective effects of LM hydrolysates in human hepatoma G2 (Hep G2) cells challenged with lipopolysaccharide (LPS)/D-Galactosamine (D-Gal), a model of liver injury. Remarkably, LM hydrolysates significantly ameliorated cell damage, as evidenced by the inhibition of the LPS/D-Gal-induced decrease in cell viability and reduction in lactate dehydrogenase (LDH) release. Furthermore, LM hydrolysates alleviated the release of aspartate aminotransferase (AST) from cells exposed to LPS/D-Gal and lowered the secretion of inflammatory cytokines while suppressing the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a key pathway in inflammation. In particular, LM-N hydrolysate mitigated hepatotoxicity by attenuation of inflammatory responses to reduce interleukin 6 (IL-6) levels, and NF-κB nuclear translocation. These findings suggest that LM hydrolysates could potentially offer hepatoprotective effects by mitigating the inflammatory responses induced by LPS/D-Gal.

3'-Daidzein Sulfonate Sodium Protects against Glutamate-induced Neuronal Injuries by Regulating NMDA Receptors.

It was previously found that 3'-Daidzein Sulfonate Sodium (DSS) exhibits protective effects on Cerebral Ischemia-Reperfusion Injury (CI/RI). This study aimed to explore the underlying molecular mechanisms involved in the neuroprotective effects of DSS against ischemic stroke. In this study, rats with transient middle cerebral artery occlusion (tMCAO) were used as an in vivo model, whereas PC12 cells treated with glutamate alone and rat primary cortical neurons treated with the combination of glutamate and glycine were used as in vitro models. Cell viability and lactate dehydrogenase (LDH) release were used to evaluate cell injury. Cell apoptosis was determined by flow cytometry. Quantitative polymerase chain reaction (qPCR), Western blotting, and immunofluorescent staining methods were used to determine the mRNA expressions and protein levels and location. It was found that DSS significantly suppressed the impaired viability of PC12 cells induced by glutamate. DSS also increased cell viability while reducing the LDH release and apoptosis in primary cortical neurons injured by glutamate and glycine. In addition, DSS decreased GluN2B subunit expression while enhancing the expressions of GluN2A subunit and PSD95 in tMCAO rats' brains. This study demonstrated that DSS protects against excitotoxic damage in neurons by regulating the expression of NMDA receptors and PSD95 in the brain with cerebral ischemia-reperfusion injury. Our findings provide experimental evidence for the potential clinical administration of DSS in ischemic stroke.

Influence of Hypoxic Condition on Cytotoxicity, Cellular Migration, and Osteogenic Differentiation Potential of Aged Periodontal Ligament Cells.

This study aimed to investigate and compare the influence of hypoxic conditions on cytotoxicity, cellular migration, and osteogenic differentiation of aged periodontal ligament (PDL) cells. Isolated human PDL cells from aged and young subjects were cultured under hypoxic conditions, which were treated with hydrogen peroxide (H2O2) (0, 25, 50, 100, 200, and 500 µM). To assess cytotoxicity, lactate dehydrogenase release was determined by the optical density at 490 nm, and the percentage of cell death was calculated. An in vitro wound healing assay was performed over 24 to 48 hours for cellular migration determination. Osteogenic differentiation was determined by alizarin red staining and osteogenic gene expression, including the expression of runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and osteopontin (OPN). There was a significant difference in the percentage of cell death with high hypoxic condition (200 and 500 µM) compared to low hypoxic conditions on both day 1 and 2. The highest cellular migration was depicted at 50 µM in both young and aged groups of the in vitro wound healing assay. Osteogenic gene expression of RUNX2 in the aged group was increased at 25 and 50 µM hypoxic condition at day 7, but the expression was gradually decreased after 14 days. On the contrary, the expression of ALP and OPN in the aged group was increased at day 14. Only OPN had been found to be statistically significantly different when compared with gene expression at day 7 and 14 (p < 0.05). The results showed no statistically significant differences when compared with the young and aged groups in all genes and all concentrations. The concentration of low hypoxic condition (25-50 µM) was proposed to promote cell viability, cellular migration, and osteogenic differentiation in aged PDL cells. We suggested that the potential of aged PDL cells for use in cell therapy for periodontal regeneration might possibly be similar to that of young PDL cells.

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.

Inhibitory Effect of Puerarin on Lipopolysaccharide-triggered Inflammatory Responses of Bovine Kidney Cells.

Puerarin (Pue), a flavonoid compound, possesses cytoprotective effects and LPS has been reported to induce renal inflammatory injury in bovine. However, whether Pue inhibits lipopolysaccharide (LPS)-induced inflammatory damage of bovine kidney cells remains unknown. Based on an in vitro model with Madin-Darby bovine kidney (MDBK) cell line, it has found that Pue attenuated LPS-induced damage of MDBK cells, as evidenced by cell viability and lactic dehydrogenase (LDH) release rescued by Pue (P < 0.05). Additionally, the real-time quantitative PCR (qPCR) and enzyme linked immunosorbent assay (ELISA) showed that LPS elevated the levels of pro-inflammatory factors interleukin (IL)-1β, IL-8 and tumor necrosis factor (TNF)-α, which was reversed by pretreatment of Pue (P < 0.05). Besides, Pue reduced the expression of Toll like receptor 4 (TLR4) and phosphorylated nuclear factor kappa B (p-NF-κB) of LPS-exposed MDBK cells (P < 0.05). Collectively, these results showed that Pue suppresses LPS-evoked inflammatory damage of bovine kidney cells, suggesting Pue a potential compound for intervention of bovine inflammation.

Tibetan-Origin Edible Chinese Herbal Prescription C18 Protects H9C2 Cardiomyocytes from Cobalt Chloride-induced Hypoxia Injury Through the PI3K/AKT Signaling Pathway

Background Altitude sickness is often prone to occur during tourism or work in high-altitude areas. In China, traditional Tibetan medicines have a long history of preventing or treating altitude sickness, especially altitude hypoxia, which may lead to myocardial cell apoptosis and myocardial hypoxia-reoxygenation injury. Purpose This study investigated the effect of a Tibetan-origin edible Chinese herbal prescription (named C18) on protecting H9C2 cardiomyocytes from cobalt chloride-induced hypoxia injury and its potential mechanism. Methods In this study, a hypoxic injury model of H9C2 cardiomyocytes induced by cobalt chloride was established first. Then the cell viability, relevant antioxidant indicators malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and protein expression (hypoxia-inducible factor 1 alpha (HIF-1α), phosphoinositide 3-kinase (PI3K), phosphorylated protein kinase B (p-AKT)) were measured after pretreatment with or without C18. At last, the specific PI3K/AKT inhibitor LY294002 was applied to verify the antihypoxia signaling pathway. Results C18 could significantly promote normal H9C2 cardiomyocyte proliferation and inhibit apoptosis of hypoxic H9C2 cardiomyocytes, reduce the release of lactate dehydrogenase and MDA, and increase the levels of SOD and GSH-Px antioxidant enzymes. In addition, C18 could significantly downregulate the expression of HIF-1α protein and upregulate the expression of intracellular p-AKT. Moreover, these effects of C18 can be blocked by the specific PI3K/AKT inhibitor LY294002. Conclusion C18 protects H9C2 cardiomyocytes from cobalt chloride-induced hypoxia injury through the PI3K/AKT signaling pathway.

Upregulated dual oxidase 1-induced oxidative stress and caspase-1-dependent pyroptosis reflect the etiologies of heart failure

BackgroundOxidative stress is implicated in the pathogenesis of heart failure. Dual oxidase 1 (DUOX1) might be important in heart failure development through its mediating role in oxidative stress. This study was designed to evaluate the potential role of DUOX1 in heart failure.Materials and methodsAC16 cells were treated with 2 µmol/L of doxorubicin (DOX) for 12, 24, and 48 h to construct a heart failure model. DUOX1 overexpression and silencing in AC16 cell were established. DUOX1 expression was detected by Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Pyroptosis and reactive oxygen species (ROS) production were measured by flow cytometry.ResultsIncreased DUOX1 expression levels were observed after DOX treatment for 24 h in AC16 cells. DUOX1 silencing inhibited DOX-induced pyroptosis and ROS production. The release of IL-1β, IL-18, and lactate dehydrogenase (LDH), and expression levels of pyroptosis-related proteins were also decreased. DUOX1 overexpression increased pyroptosis, ROS production, IL-1β, IL-18, and LDH release, and pyroptosis-related protein expression. N-acetyl-cysteine (NAC) significantly reversed DUOX1-induced pyroptosis, ROS, and related factors.ConclusionThese results suggest that DUOX1-derived genotoxicity could promote heart failure development. In the process, oxidative stress and pyroptosis may be involved in the regulation of DUOX1 in heart failure.

The AMPK activator ATX-304 alters cellular metabolism to protect against cisplatin-induced acute kidney injury

Acute kidney injury (AKI) disrupts energy metabolism. Targeting metabolism through AMP-activated protein kinase (AMPK) may alleviate AKI. ATX-304, a pan-AMPK activator, was evaluated in C57Bl/6 mice and tubular epithelial cell (TEC) cultures. Mice received ATX-304 (1 mg/g) or control chow for 7 days before cisplatin-induced AKI (CI-AKI). Primary cultures of tubular epithelial cells (TECs) were pre-treated with ATX-304 (20 µM, 4 h) prior to exposure to cisplatin (20 µM, 23 h). ATX-304 increased acetyl-CoA carboxylase phosphorylation, indicating AMPK activation. It protected against CI-AKI measured by serum creatinine (control 0.05 + 0.03 mM vs ATX-304 0.02 + 0.01 mM, P = 0.03), western blot for neutrophil gelatinase-associated lipocalin (NGAL) (control 3.3 + 1.8-fold vs ATX-304 1.2 + 0.55-fold, P = 0.002), and histological injury (control 3.5 + 0.59 vs ATX-304 2.7 + 0.74, P = 0.03). In TECs, pre-treatment with ATX-304 protected against cisplatin-mediated injury, as measured by lactate dehydrogenase release, MTS cell viability, and cleaved caspase 3 expression. ATX-304 protection against cisplatin was lost in AMPK-null murine embryonic fibroblasts. Metabolomic analysis in TECs revealed that ATX-304 (20 µM, 4 h) altered 66/126 metabolites, including fatty acids, tricarboxylic acid cycle metabolites, and amino acids. Metabolic studies of live cells using the XFe96 Seahorse analyzer revealed that ATX-304 increased the basal TEC oxygen consumption rate by 38%, whereas maximal respiration was unchanged. Thus, ATX-304 protects against cisplatin-mediated kidney injury via AMPK-dependent metabolic reprogramming, revealing a promising therapeutic strategy for AKI.

Neuroprotective effects of apigenin on retinal ganglion cells in ischemia/reperfusion: modulating mitochondrial dynamics in in vivo and in vitro models

BackgroundRetinal ischemia/reperfusion (RIR) is implicated in various forms of optic neuropathies, yet effective treatments are lacking. RIR leads to the death of retinal ganglion cells (RGCs) and subsequent vision loss, posing detrimental effects on both physical and mental health. Apigenin (API), derived from a wide range of sources, has been reported to exert protective effects against ischemia/reperfusion injuries in various organs, such as the brain, kidney, myocardium, and liver. In this study, we investigated the protective effect of API and its underlying mechanisms on RGC degeneration induced by retinal ischemia/reperfusion (RIR).MethodsAn in vivo model was induced by anterior chamber perfusion following intravitreal injection of API one day prior to the procedure. Meanwhile, an in vitro model was established through 1% oxygen and glucose deprivation. The neuroprotective effects of API were evaluated using H&E staining, spectral-domain optical coherence tomography (SD-OCT), Fluoro-Gold retrograde labeling, and Photopic negative response (PhNR). Furthermore, transmission electron microscopy (TEM) was employed to observe mitochondrial crista morphology and integrity. To elucidate the underlying mechanisms of API, the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, flow cytometry assay, western blot, cell counting kit-8 (CCK-8) assay, lactate dehydrogenase (LDH) assay, JC-1 kit assay, dichlorofluorescein-diacetate (DCFH-DA) assay, as well as TMRE and Mito-tracker staining were conducted.ResultsAPI treatment protected retinal inner plexiform layer (IPL) and ganglion cell complex (GCC), and improved the function of retinal ganglion cells (RGCs). Additionally, API reduced RGC apoptosis and decreased lactate dehydrogenase (LDH) release by upregulating Bcl-2 and Bcl-xL expression, while downregulating Bax and cleaved caspase-3 expression. Furthermore, API increased mitochondrial membrane potential (MMP) and decreased extracellular reactive oxygen species (ROS) production. These effects were achieved by enhancing mitochondrial function, restoring mitochondrial cristae morphology and integrity, and regulating the expression of OPA1, MFN2, and DRP1, thereby regulating mitochondrial dynamics involving fusion and fission.ConclusionAPI protects RGCs against RIR injury by modulating mitochondrial dynamics, promoting mitochondrial fusion and fission.

From Epimedium to Neuroprotection: Exploring the Potential of Wushanicaritin.

Epimedium has been used for functional foods with many beneficial functions to human health. Wushanicaritin is one of the most important chemicals int Epimedium. This study investigated the neuroprotective effects of wushanicaritin and potential underlying mechanisms. The results demonstrated that wushanicaritin possessed superior intercellular antioxidant activity compared to icaritin. Wushanicaritin, with an EC50 value of 3.87 μM, showed better neuroprotective effect than quercetin, a promising neuroprotection agent. Wushanicaritin significantly reversed lactate dehydrogenase release, reactive oxygen species generation, cell apoptosis, and mRNA expression related to cell apoptosis and oxidative defense, in glutamate-induced PC-12 cells. Wushanicaritin could also maintain the enzymatic antioxidant defense system and mitochondrial function. The suppression of caspase-3 activation and amelioration of mitochondrial membrane potential loss and nucleus morphology changes were involved in the antiapoptotic effect of wushanicaritin. These findings suggested that wushanicaritin possesses excellent intercellular antioxidant and neuroprotective activities, showing potential promise in functional foods.

Green and chemical syntheses of silver nanoparticles: Comparative and comprehensive study on characterization, therapeutic potential, and cytotoxicity

The emergence of metallic nanoparticles through green synthesis has garnered significant recognition, shaping global research efforts towards eco-friendly practices, often termed as the green revolution. Specifically, the green synthesis of silver nanoparticles (AgNPs) has made considerable strides in the past decade, becoming a prominent fixture in the realm of science and technology. The study explores the synthesis and characterization of silver nanoparticles (AgNPs) using Cassia fistula L. flowers extract through chemical co-precipitation (CM_AgNPs) and green methods (CFF_AgNPs). Characterization techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), attenuated total reflectance fourier-transform infrared (FTIR), and X-ray diffraction (XRD), revealed irregular morphologies with agglomeration, polycrystalline nature, and intrinsic functional groups involved in capping AgNPs. Antioxidant assessment demonstrated superior antioxidative activity (84.48 %) in green-synthesized nanoparticles compared to chemically synthesized ones (75.87 %), and they exhibited dose-dependent anti-inflammatory effects with IC50 values CFF_AgNPs_30.19 μg/mL and CM_AgNPs _34.14 μg/mL respectively. The lower IC50 value of CFF_AgNPs_30.19 μg/mL signifies finer and better activity due to the presence of phytochemicals present in it. Whereas for CM_AgNPs the IC50 value is a 34.14 μg/mL which is solely due to AgNPs. To ensure the promising therapeutic aspects of AgNPs with a careful assessment of their safety profile, cytotoxicity of AgNPs on HEP3B cancer cells was evaluated through MTT assay, lactate dehydrogenase (LDH) release, and reactive oxygen species (ROS) level measurement. In the in vitro cytotoxicity evaluation, HEP3B demonstrated more pronounced dose-dependent adverse effects upon exposure to CFF_AgNPs compared to CM_AgNPs. This study underscores the bioactive potential of Cassia fistula L. mediated AgNPs, suggesting promising applications in biomedicine with environmental sustainability. The findings contribute to the growing interest in green synthesis methods for metallic nanoparticles and their potential benefits in various fields.

Brucella Manipulates Host Cell Ferroptosis to Facilitate Its Intracellular Replication and Egress in RAW264.7 Macrophages.

Brucella virulence relies on its successful intracellular life cycle. Modulating host cell death is a strategy for Brucella to survive and replicate intracellularly. Ferroptosis is a novel regulated cell death characterized by iron-triggered excessive lipid peroxidation, which has been proven to be associated with pathogenic bacteria infection. Thus, we attempted to explore if smooth-type Brucella infection triggers host cell ferroptosis and what role it plays in Brucella infection. We assessed the effects of Brucella infection on the lactate dehydrogenase release and lipid peroxidation levels of RAW264.7 macrophages; subsequently, we determined the effect of Brucella infection on the expressions of ferroptosis defense pathways. Furthermore, we determined the role of host cell ferroptosis in the intracellular replication and egress of Brucella. The results demonstrated that Brucella M5 could induce ferroptosis of macrophages by inhibiting the GPX4-GSH axis at the late stage of infection but mitigated ferroptosis by up-regulating the GCH1-BH4 axis at the early infection stage. Moreover, elevating host cell ferroptosis decreased Brucella intracellular survival and suppressing host cell ferroptosis increased Brucella intracellular replication and egress. Collectively, Brucella may manipulate host cell ferroptosis to facilitate its intracellular replication and egress, extending our knowledge about the underlying mechanism of how Brucella completes its intracellular life cycle.

Protective Effect of Boric Acid Against Ochratoxin A-Induced Toxic Effects in Human Embryonal Kidney Cells (HEK293): A Study on Cytotoxic, Genotoxic, Oxidative, and Apoptotic Effects.

The present study evaluates the protective properties of boric acid (BA) against the toxic effects induced by ochratoxin A (OTA) in human embryonic kidney cells (HEK293). The focus is on various parameters such as cytotoxicity, genotoxicity, oxidative stress, and apoptosis. OTA is a known mycotoxin that has harmful effects on the liver, kidneys, brain, and nervous system. BA, on the other hand, a boron-based compound, is known for its potential as a vital micronutrient with important cellular functions. The results show that BA administration not only increases cell viability but also mitigates the cytotoxic effects of OTA. This is evidenced by a reduction in the release of lactate dehydrogenase (LDH), indicating less damage to cell membranes. In addition, BA shows efficacy in reducing genotoxic effects, as the frequency of micronucleus (MN) and chromosomal aberrations (CA) decreases significantly, suggesting a protective role against DNA damage. In addition, the study shows that treatment with BA leads to a decrease in oxidative stress markers, highlighting its potential as a therapeutic intervention against the deleterious effects of OTA. These results emphasize the need for further research into the protective mechanisms of boron, particularly BA, in combating cell damage caused by OTA.

Lycopene promoted M2 macrophage polarization via inhibition of NOTCH1-PI3K-mTOR-NF-κB-JMJD3-IRF4 pathway in response to Escherichia coli infection in J744A.1 cells.

Escherichia coli (E. coli) can induce severe clinical bovine mastitis, which is to blame for large losses experienced by dairy farms. Macrophage polarization into various states is in response to pathogen infections. Lycopene, a naturally occurring hydrocarbon carotenoid, relieved inflammation by controlling M1/M2 status of macrophages. Thus, we wanted to explore the effect of lycopene on polarization states of macrophages in E. coli-induced mastitis. Macrophages were cultivated with lycopene for 24, before E. coli inoculation for 6h. Lycopene (0.5μmol/L) significantly enhanced cell viabilities and significantly reduced lactic dehydrogenase (LDH) levels in macrophages, whereas 2 and 3μmol/L lycopene significantly enhanced LDH activities. Lycopene treatment significantly reduced the increase in LDH release, iNOS, CD86, TNF-α, IL-1β and phosphatase and tensin homolog (PTEN) expressions in E. coli group. 0.5μmol/L lycopene significantly increased E. coli-induced downregulation of CD206, arginase I (ARG1), indoleamine 2,3-dioxygenase (IDO), chitinase 3-like 3 (YM1), PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR), p-mTOR, jumonji domain-containing protein-3 (JMJD3) and interferon regulatory factor 4 (IRF4) levels. Moreover, Ginkgolic acid C17:1 (a specific PTEN inhibitor), 740YPDGFR (a specific PI3K activator), SC79 (a specific AKT activator) or CHPG sodium salt (a specific NF-κB activator) significantly decreased CD206, AGR1, IDO and YM1 expressions in lycopene and E. coli-treated macrophages. Therefore, lycopene increased M2 macrophages via inhibiting NOTCH1-PI3K-mTOR-NF-κB-JMJD3-IRF4 pathway in response to E. coli infection in macrophages. These results contribute to revealing the pathogenesis of E. coli-caused bovine mastitis, providing the new angle of the prevention and management of mastitis.

PSII-6 The interactive effects of deoxynivalenol and lipopolysaccharides on gut integrity and inflammation in IPEC-J2 cells

Abstract The objective of this research is to investigate the interactive effects of deoxynivalenol (DON) and lipopolysaccharides (LPS) on gut integrity and inflammation using porcine intestinal epithelial cell line (IPEC-J2). Three experiments were conducted in this study: Exp 1: cells were treated with control, DON (0.5 ppm) or LPS (10 ug/mL) individually and combination of DON and LPS for 24 h, then measure the Lactate dehydrogenase (LDH) release and interleukin 8 (IL8) production in medium and measure the transepithelial electric resistance (TEER) and FITC-dextran passage rate at the end of each experiment. 2) Treat the cells with control or DON for 24 h, then split the two groups for control or LPS treatment for additional 24 h; same measurements were taken as in experiment 1; 3) Treat the cells with control or LPS for 24 h, then split the two groups for control or DON treatment for additional 24 h; same measurements were taken as in previous experiments. In each experiment, six replications were done. Data were analyzed for the effect of DON, LPS and their interaction. Treatments did not affect the LDH in all experiments except for the high LDH release in the treatment of LPS followed by DON in experiment 3. In experiment 1, DON, LPS or combination of DON and LPS significantly reduced the TEER value by 15.1%, 21.7% and 23.9% respectively with only DON has effect on FITC-dextran passage rate (P &amp;lt; 0.001). LPS significantly increased IL8 secretion in the medium (P &amp;lt; 0.001). In experiment 2, DON or LPS decreased TEER value whereas the cells treated with DON before were more susceptible to LPS (23.6% more reduction compared without DON treatment before). Similarly, the FITC-dextran passage rate was also increased by LPS in the cells exposed to DON before (P &amp;lt; 0.05). In addition, LPS significantly increased IL8 secretion no matter the cells was exposed to DON before. In experiment 3, DON or LPS decreased TEER value (P &amp;lt; 0.05) and cells treated with LPS before were more susceptible to DON (11.8% more reduction compared with no LPS treatment before). However, only DON increased FITC-dextran passage rate. The secretion of IL8 increased by DON or LPS with greatest secretion when cells treated with DON which exposed to LPS before (P &amp;lt; 0.05). In conclusion, the results suggested that cells were more susceptible to LPS when the cells were exposed to DON before or vice versa, and the synergetic effect is limited when LPS and DON were added to cells simultaneously.

Dissecting the negative influence mechanisms of microplastics on plant and microbial mediated nitrogen removal in constructed wetlands

The escalating prevalence of microplastics (MPs) in constructed wetlands (CWs) raises concerns about their potential effects on nitrogen (N) removal within these ecosystems. Despite this, systematic investigations into the influence of MPs on N-transformation in CWs, encompassing both phytological and microbial dimensions, are notably lacking. Thus, polyethylene (PE) and polyamide (PA), commonly found in wastewater plants, were studied as typical MPs in CWs over 240 days. Extended accumulation time increased nitrogen inhibition in CWs with PE and PA MPs, notably in PA, reducing TN removal by 7.0 % and 10.5 %. For nitrification process, MPs inhibited the relative abundances (RAs) of genes involved in nitrification and carbon fixation metabolisms in nitrifiers through metagenomic analysis, with PA more significantly inhibiting nitrifying enzyme activities. Regarding denitrification, MPs, especially PA, inhibited the RAs of genes involved in electron production, transport, consumption, ATP production and central carbon metabolism in denitrifiers, and activities of denitrifying enzymes. MPs, particularly PA, were found to elevated ROS level and lactate dehydrogenase release, thus hindering nitrogen transformation. Moreover, MPs caused a reduction in c-di-GMP levels and inhibited genes relevant to biofilm regulation (c-di-GMP signaling and quorum sensing), thereby disturbing extracellular polymeric substance metabolism. Regarding plant systems, MPs, particularly PA, were observed to decrease nitrogen uptake, crucial for N-removal. Additionally, inhibited root activity, reduced photosynthesis, and a compromised antioxidant system also contributed to the diminished N-removal in CWs. Overall, our study systematically reveals how MPs, especially PA, impede nitrogen removal in CWs, contributing to further realize the simultaneous removal of MPs and nitrogen in CWs.

Divergent effects of copper oxide nanoparticles on methanotrophs: Stimulation at low concentrations and inhibition at high concentrations

Methanotrophs represent pivotal microorganisms, integral to the regulation of global methane emissions. Upon introduction into the environment, copper oxide nanoparticles (CuO NPs), a frequently employed category of inorganic nanomaterials, possess the potential to exert influences on methanotrophs. This study investigated the impact of CuO NPs on methanotrophs, showing a clear concentration-dependent response. Under high concentrations, exposure of methanotrophs to CuO NPs induced the production of reactive oxygen species, compromised cell membrane integrity, and resulted in the substantial release of lactate dehydrogenase. The expressions of genes encoding methane monooxygenase were obviously down-regulated. Whereas under low concentrations, a distinct enhancement of bacterial growth and metabolism was observed. The presence of methanotrophs facilitated the release of Cu2+ from CuO NPs, and the Cu2+ stimulated the biosynthesis of particulate methane monooxygenase reversely. Compared to the cellular toxicity of CuO NPs as nanoparticles, the released Cu2+ exerted a more pronounced promoting effect on methanotrophs growth, resulting in an overall strengthened methane metabolism. Significant alterations were observed in genes encoding copper uptake and resistance, cytochrome-related and heme-related proteins. This study provides novel insights into interactions between methanotrophs and nanoparticles, thereby advancing our comprehension of the impact of CuO NPs on methane emissions within an environmental context.

A new model of ischemia/reperfusion injury using precision-cut liver slices

Background: Primary cells isolated from the liver are widely used to investigate hepatic pathophysiology. However, these cells do not represent cell-to-cell interactions, three dimensional architecture, and zonal structure in the liver. Furthermore, characterization of cellular and molecular events during ischemia/reperfusion (I/R) is challenging in liver biopsies. Thus, a new model of I/R injury resembling the native liver is needed. Methods: We generated precision-cut liver slices (PCLS) from mouse and human livers using a Krumdieck automatic tissue slicer (Alabama R &amp; D, Munford, AL). Thickness of individual PLCL was 200 microns. To simulate anoxia, nutrient depletion, and tissue acidosis during ischemia, PCLS were incubated in Krebs-Ringer-N-(2-Hydroxyethyl)piperazine-N-(2-ethanesulfonic acid) (HEPES) solution at pH 6.2 in the anaerobic chamber (Coy Laboratory, Grass Lake, MI) for 30 min. To simulate normoxia, nutrient repletion, and restoration to normal pH during reperfusion, ischemic PCLS were aerobically incubated in Dulbecco's modified eagle medium (DMEM) at pH 7.4 for up to 4 h. Changes in tissue viability were assessed with the release of lactate dehydrogenase (LDH) into the extracellular medium. Some PCLS were labeled with green fluorescent rhodamine-123 (Rd-123, mitochondrial membrane potential indicator) and red fluorescent propidium iodide (PI, necrosis marker). Confocal images of PCLS were collected after I/R. Results: LDH release assay revealed that while PCLS from chow diet (CD)-fed lean mice tolerated I/R injury well, those from high fat diet (HFD)-fed steatotic mice were susceptible to I/R injury. Confocal microscopy showed substantial mitochondrial depolarization (loss of Rd-123) and necrosis (nuclear labeling of PI) in the HFD group, which was, however, minimally observed in the CD group. Of importance, mitochondrial dysfunction and cell death after reperfusion occurred predominantly in hepatocytes. Heightened I/R injury in steatotic livers was also confirmed in primary hepatocytes isolated from either CD- or HFD-fed mice. To compare the similarities and differences between mouse and human livers, PCLS were generated from discarded human livers deemed unsuitable for transplant and subjected to 30 min of in vitro ischemia. The loss of mitochondrial membrane potential and hepatocyte death progressively increased after I/R in discarded human livers. At 1 h after reperfusion, diffusive fluorescence of Rd-123 and nuclear labeling of PI became evident, indicative of mitochondrial dysfunction and tissue injury after I/R. SUMMARY: LDH assay and confocal analysis of PCLS demonstrated heightened susceptibility of steatotic livers to I/R injury. In contrast to PCLS from lean livers, those from steatotic livers rapidly developed mitochondrial depolarization and onset of necrosis, cardinal features of I/R injury, even after short ischemia. The early phase of reperfusion injury in steatotic livers occurred predominantly in parenchymal cells. CONCLUSION: In vitro I/R with PCLS is a model suitable for hepatic I/R injury. This work (J-S K) was funded by the National Institutes of Health (DK079878), Mid-America Transplant Foundation (07201903), Foundation for Barnes-Jewish Hospital (4776, 5153), and Washington University Department of Surgery Pilot Grant. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.