Expression Of Kelch-like ECH-associated Protein Research Articles

The role of the KEAP1-NRF2 signaling pathway in form deprivation myopia guinea pigs.

In recent years, the global prevalence of myopia has reached an unprecedented level, especially‌ in East Asia. Multitude of studies has shown that the etiology of myopia is complex. Some researchers have suggested that oxidative stress (OS) may contribute to myopia, although there are limited reports on the alterations of related signaling pathways. Notably, the Kelch-like ECH-associated protein 1 (KEAP1) -nuclear factor erythroid 2-related factor 2 (NRF2), which plays a significant role in regulating OS and the mechanism, has not been explored in myopia. To investigate the modulation of KEAP1-NRF2 signaling pathway and its downstream superoxide dismutase (SOD) during the development of form-deprivation myopia, three-week-old guinea pigs were randomly assigned to four groups: negative control (NC), self-control (SC), form-deprivation myopia (FDM), and FDM group treated with tert-butylhydroquinone (TBHQ). Spherical equivalent (SE) and axial length (AL) were measured by retinoscopy and A-scan ultrasound, respectively. The results revealed that TBHQ treatment decelerated the progression in SE and AL changes. Immunohistochemistry (IHC) assessed the distribution and expression of KEAP1, NRF2, and SOD. The results shown that they located in the retinal ganglion cells (RGC). Subsequently, retinal mRNA and protein expression levels of KEAP1, NRF2, and SOD were quantified using real-time polymerase chain reaction (RT-PCR) and Western blot (WB) analysis. The RT-PCR and WB results demonstrated that TBHQ could activate NRF2, induce KEAP1 degradation, and enhance the expression of the antioxidant SOD. In summary, the modulation of KEAP1-NRF2 and it downstream SOD expression could alter the retinal antioxidant capacity and influence the development of myopia.

Deer Blood Hydrolysate Protects against D-Galactose-Induced Premature Ovarian Failure in Mice by Inhibiting Oxidative Stress and Apoptosis.

Premature ovarian failure (POF) is a common disease among women, which can cause many complications and seriously threaten women's physical and mental health. Currently, hormone replacement therapy is the primary treatment for premature ovarian failure. However, the side effects are serious and will increase the chance of breast cancer and endometrial cancer. Deer blood hydrolysate (DBH) is the product of enzymatic hydrolysis of deer blood, has antioxidant, anti-ageing, and anti-fatigue effects, and has the potential to improve premature ovarian failure. In our experiment, a mouse model of premature ovarian failure was established through intraperitoneal injection of 400 mg/kg/d of D-gal for 42 days. At the same time, different doses of DBH were gavaged to observe its ameliorative effect on premature ovarian failure. The experimental findings indicated that DBH could restore the irregular oestrus cycle of POF mice, improve the abnormal amounts in serum hormones follicle-stimulating hormone (FSH), luteinising hormone (LH), progesterone (P) and estradiol (E2), increase the number of primordial follicles and decrease the number of atretic follicles. In addition, DBH also raised the level of superoxide dismutase (SOD) and reduced the level of malondialdehyde (MDA) and reduced the apoptosis of ovarian granulosa cells in mice. The WB assay results showed that gavage of DBH restored the decrease in the indication of nuclear factor erythroid 2-related factor 2 (Nrf2), Heme Oxygenase-1 (Ho-1), and B-cell lymphoma-2 (Bcl-2) proteins and reduced the elevated expression of Kelch-like ECH-associated protein 1 (Keap1), Bcl-2 associated X protein (Bax), and Cysteinyl aspartate specific proteinase-3 (Caspase-3) proteins that were induced by D-gal. To sum up, the present research indicated that DBH can ameliorate D-gal-induced oxidative stress and apoptosis by regulating the Nrf2/HO-1 signalling pathway and the Bcl-2/Bax/caspase-3 apoptosis pathway, which can be used for further development as a nutraceutical product to improve premature ovarian failure.

Effect of Agkistrodon acutus venom (AAVC-I) on apoptosis through modulation of the Keap1/Nrf2 pathway in HSC-3 oral squamous cell carcinoma cells.

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor in the oral and maxillofacial regions. Patients with OSCC exhibit a poor response to conventional chemoradiotherapies, which are associated with severe side effects. Therefore, it is essential to identify an effective therapeutic method to treat patients with OSCC. An anti-tumor compound, Agkistrodon acutus venom component I (AAVC-I), purified from Agkistrodon acutus venom, has demonstrated anticancer activity both in vitro and in vivo. However, the mechanism of AAVC-I's anticancer activity in cancer cells has yet to be established. This study aimed to investigate the mechanism of AAVC-I-induced apoptosis in HSC-3 OSCC cells and explore its regulatory effect on oxidative stress. Survival rates of human OSCC cell HSC-3 were detected by Cell Counting Kit-8 (CCK-8). The reactive oxygen species (ROS) level was analyzed by flow cytometry and fluorescence microscopy. The mitochondrial membrane potential was analyzed by cytometry and fluorescent microplate reader. Apoptosis of HSC-3 cells was analyzed using flow cytometry. The oxidative stress level was evaluated using glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) kits. In addition, the target proteins were analyzed by western blot. AAVC-I reduced HSC-3 cells' survival rates in a dose-dependent manner with a 50% inhibiting concentration (IC50) of 8.86 µg/mL. It induced apoptosis of HSC-3 cells and the expression of cleaved caspase-3, cleaved caspase-9, and Cyt-c increased significantly, whereas the expression level of Bcl-2 decreased in AAVC-I-treated HSC-3 cells. Thus, AAVC-I caused apoptosis of HSC-3 via the activation of the intrinsic apoptotic pathway. In addition, AAVC-I reduced the mitochondrial membrane potential in HSC-3, enhanced intracellular ROS, and increased intracellular oxidative stress levels in comparison to that of untreated control cells. Furthermore, AAVC-I increased the expression of Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2 (Keap1/Nrf2) levels. These findings demonstrate the inhibitory effects and associated mechanisms of AAVC-I on the HSC-3 OSCC cell line. This insight could be valuable for investigating AAVC-I as a potential therapeutic option for patients with OSCC.

Oxidised rice bran oil induced oxidative stress and apoptosis in IPEC-J2 cells via the Nrf2 signalling pathway.

Rice bran oil is a type of rice oil made by leaching or pressing during rice processing and has a high absorption rate after consumption. When oxidative rancidity occurs, it may cause oxidative stress (OS) and affect intestinal function. Meanwhile, the toxic effects of oxidised rice bran oil have been less well studied in pigs. Therefore, the IPEC-J2 cells model was chosen to explore the regulatory mechanisms of oxidised rice bran oil on OSand apoptosis. Oxidised rice bran oil extract treatment(OR) significantly decreased the viability of IPEC-J2 cells. The results showed that OR significantly elevated apoptosis and reactive oxygen species levelsand promoted the expression of pro-apoptotic gene Caspase-3 messenger RNA levels. The activation of Nrf2 signalling pathway by OR decreased the cellular antioxidant capacity. This was further evidenced by the expression of kelch-like ECH-associated protein 1, heme oxygenase 1, NADH: quinone oxidoreductase 1, superoxide dismutase2and heat shock 70 kDa protein genes and proteins were all downregulated. In conclusion, our results suggested that oxidised rice bran oil induced damage in IPEC-J2 cells through the Nrf2 signalling pathway.

Sakuranetin counteracts polyethylene microplastics induced nephrotoxic effects via modulation of Nrf2/Keap1 pathway

Polyethylene microplastics (PEMPs) are widely distributed in environment and exerts deleterious effects on animal as well as human health. Sakuranetin (SKN) is a natural flavonoid that manifests profound therapeutic potential. Albino rats (n = 24) were partitioned into 4 groups i.e., Control, PEMPs 1.5 mg/kg, PEMPs 1.5 mg/kg + SKN 10 mg/kg and SKN 10 mg/kg administered group. After 30 days of treatment, our results revealed that PEMPs exposure reduced nuclear factor erythroid 2–related factor 2 (Nrf-2) and antioxidant genes while enhancing the expression of kelch-like ECH-associated protein 1(Keap-1). Besides, PEMPs intoxication reduced the level of renal biomarkers i.e., creatinine clearance and increased the level of creatinine, urea, neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1). Additionally, it lessened the activities of glutathione S-transferase (GST), superoxide dismutase (SOD), glutathione reductase (GSR), catalase (CAT), glutathione peroxidase (GPx) and heme oxygenase-1 (HO-1) whereas the levels of malondialdehyde (MDA) and reactive oxygen species (ROS) were increased. Conversely, it increased the levels of nuclear factor-kappa B (NF-kB), tumor necrosis factor-alpha (TNF-a), interleukin-1beta (IL-1b) and IL-6 as well as escalated the activity of cyclooxygenase-2 (COX-2). Furthermore, the expression of bcl-2-associated X protein (Bax) and caspase-3 were elevated, while the expression of B-cell lymphoma 2 (Bcl-2) was lowered. However, SKN treatment significantly (P < 0.05) restored aforementioned renal impairments. Therefore, it is proposed that SKN may be applied as a nephroprotective agent against the PEMPs-prompted renal toxicity.

The Combination of Gefitinib and Acetaminophen Exacerbates Hepatotoxicity via ROS-Mediated Apoptosis.

Gefitinib is the well-tolerated first-line treatment of non-small cell lung cancer. As it need for analgesics during oncology treatment, particularly in the context ofthe coronavirus disease, where patients are more susceptible to contract high fever and sore throat. This has increased the likelihood of taking both gefitinib and antipyretic analgesic acetaminophen (APAP). Given that gefitinib and APAP overdose can predispose patients to liver injury or even acute liver failure, there is a risk of severe hepatotoxicity when these two drugs are used concomitantly. However, little is known regarding their safety at therapeutic doses. This study simulated the administration of gefitinib and APAP at clinically relevant doses in an animal model and confirmed that gefitinib in combination with APAP exhibited additional hepatotoxicity. We found that gefitinib plus APAP significantly exacerbated cell death, whereas each drug by itself had little or minor effect on hepatocyte survival. Mechanistically, combination of gefitinib and APAP induces hepatocyte death via the apoptotic pathway obviously. Reactive oxygen species (ROS) generation and DNA damage accumulation are involved in hepatocyte apoptosis. Gefitinib plus APAP also promotes the expression of Kelch-like ECH-associated protein 1 (Keap1) and downregulated the antioxidant factor, Nuclear factor erythroid 2-related factor 2 (Nrf2), by inhibiting p62 expression. Taken together, this study revealed the potential ROS-mediated apoptosis-dependent hepatotoxicity effect of the combination of gefitinib and APAP, in which the p62/Keap1/Nrf2 signaling pathway participates and plays an important regulatory role.

Linking renal hypoxia and oxidative stress in chronic kidney disease: Based on clinical subjects and animal models.

The prevalence of chronic hypoxia and oxidative stress plays a key role in the progression of chronic kidney disease (CKD), but the underlying correlations between them need further elucidation. This study aims to explore the relationships between renal function, hypoxia, and oxidative stress in CKD. Seventy-six non-dialysis patients with CKD stages 1-5 and eight healthy subjects were included in the clinical research. They were divided into three groups: healthy subjects, CKD stages 1-3, and CKD stages 4-5. In the animal study, 16 rat models of CKD were established through 5/6 renal ablation/infarction (A/I) surgery, and 8 normal rats were split into 3 groups: Sham, CKD, and losartan groups. Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) was used to measure cortical and medullary T2* values (COT2* and MET2*) in all subjects and rats to evaluate renal oxygenation. Biochemical indicators were used to assess renal function and antioxidant capacity. Furthermore, the effects of losartan on renal fibrosis, hypoxia, and oxidative stress were examined using immunoblotting, colorimetric, and fluorometric assays. The results demonstrated significant positive associations between COT2* and MET2* with estimated glomerular filtration rate (eGFR). Patients with CKD stages 4-5 showed significantly lower serum superoxide dismutase (SOD) levels, which also had positive correlations with eGFR, COT2*, and MET2*. Furthermore, losartan treatment resulted in improved renal function and fibrosis, leading to increased levels of COT2*, MET2*, and SOD levels in 5/6 A/I rats. This was accompanied by reduced levels of hypoxia-inducible factor-1 alpha (HIF-1α) and malondialdehyde. Furthermore, losartan restored the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), and suppressed the expression of Kelch-like ECH-associated protein 1 (Keap1) in 5/6 A/I kidneys. The study indicates that decline in renal oxygenation and antioxidant capacity is associated with the severity of renal failure in CKD. Losartan can potentially alleviate renal hypoxia and oxidative stress in the treatment of CKD via Keap1-Nrf2/HO-1 pathway.

Yunvjian decoction mitigates hyperglycemia in rats induced by a high-fat diet and streptozotocin via reducing oxidative stress in pancreatic beta cells

Ethnopharmacological relevanceYunvjian (YNJ), a traditional Chinese herbal formula first reported in Jing Yue Quan Shu, is commonly used in the clinical treatment of type 2 diabetes mellitus (T2DM). However, the mechanism by which YNJ affects T2DM remains unclear. Aim of the studyThis study aimed to assess the therapeutic effects of YNJ on T2DM and explore the potential mechanism involved. Materials and methodsHigh-performance liquid chromatography (HPLC) was used to identify the chemical compounds of YNJ. The anti-T2DM effects of YNJ were observed in a high-fat diet/streptozotocin induced rat model. The type 2 diabetic rats were prepared as follows: rats were fed a high-fat diet for four weeks and then intraperitoneally injected with a low dose (30 mg/kg) of streptozotocin. YNJ and the positive control metformin were used in these experiments. Biochemical assays were implemented to determine the fasting blood glucose, glucose tolerance, insulin sensitivity, serum lipid levels, and oxidative stress index of the pancreas. Hematoxylin-eosin (H&E) staining was used to assess histopathological alterations in the pancreas. The mechanism by which YNJ affects T2DM was evaluated in INS-1 cells treated with glucose and high sodium palmitate. YNJ-supplemented serum was used in these experiments. Methyl thiazolyl tetrazolium assays, enzyme-linked immunosorbent assays, Nile red staining, flow cytometric analysis, and Western blotting were used to assess apoptosis, insulin secretion, lipid accumulation, reactive oxygen species production, and protein levels. ResultsFive major compounds were identified in YNJ. In high-fat diet/streptozotocin-induced diabetic rats, YNJ-M notably decreased fasting blood glucose and lipid levels; ameliorated glucose tolerance, insulin sensitivity, and islet morphology; reduced Malondialdehyde levels; and restored superoxide dismutase activity in the pancreatic islets. Furthermore, the effect of YNJ-M was significantly greater than that of YNJ-L, and YNJ-H had little effect on diabetic rats. In vitro experiments revealed that YNJ-supplemented serum (10%, 15%, and 20%) dramatically suppressed apoptosis, mitigated intracellular lipid accumulation and reduced intracellular oxidative stress levels in a dose-dependent manner. Additionally, YNJ-supplemented serum increased the protein expression of Nuclear factor erythroid 2-related factor 2, Heme oxygenase-1, and superoxide dismutase 1 and inhibited the protein expression of Kelch-like ECH-associated protein 1. ConclusionYNJ ameliorates high-fat diet/streptozotocin induced experimental T2DM. The underlying mechanism involves reducing oxidative stress in pancreatic beta cells. The findings of this study provide scientific justification for the application of the traditional medicine YNJ in treating T2DM.

Amentoflavone mediated hepatoprotection to counteract paraquat instigated hepatotoxicity via modulating Nrf2/keap1 pathway: A biochemical, inflammatory, apoptotic and histopathological study

Paraquat (PQ) is a ubiquitous and water-soluble herbicide which has potential to cause systematic poisoning. PQ intoxication is known to be associated with various clinical complications including hepatotoxicity. Amentoflavone (AMF) is an active phenolic compound that exhibits a broad range of biological as well as pharmacological activities. This study was designed to determine the hepato-protective potential of AMF against PQ instigated hepatotoxicity in rats. Forty-eight rats were distributed into four groups such as control group, PQ-treated group (5 mg/kg), PQ (5 mg/kg) + AMF (40 mg/kg) exposed group and AMF (40 mg/kg) only supplemented group. It was revealed that PQ exposure reduced nuclear factor erythroid 2–related factor 2 (Nrf2) and antioxidative genes expression whereas increase the expression of Kelch-like ECH-associated protein 1(Keap1). Besides, PQ intoxication reduced the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GSR), glutathione peroxidase (GPx), Heme- oxygenase-1 (HO-1) & glutathione (GSH) content. Furthermore, the levels of reactive oxygen species (ROS) & malondialdehyde (MDA) were increased. In addition, PQ significantly increased the hepatic serum enzymes including alkaline phosphatase (ALP), aspartate transaminase (AST), & alanine transaminase (ALT) along with inflammatory biomarkers levels such as tumor necrosis- α (TNF- α), nuclear factor- κB (NF-κB), interleukin-6 (IL-6), interleukin 1beta (IL-1β), & cyclo‑oxygenase-2 (COX-2) activity. PQ intoxication increased the expressions of pro-apoptotic markers i.e., Bcl-2-associated X protein (Bax) & Cysteine-aspartic protease-3 (Caspase-3) while reducing the expression of anti-apoptotic protein B-cell lymphoma 2 (Bcl-2). Furthermore, PQ intoxication prompted various histopathological impairments. However, the co-administration of AMF significantly improved the abovementioned hepatic damages induced by PQ. The present study indicated that AMF may be an effective therapeutic candidate to mitigate PQ provoked hepatic impairments due to its anti-apoptotic, antioxidant & anti-inflammatory properties.

Attenuative effects of tamarixetin against polystyrene microplastics-induced hepatotoxicity in rats by regulation of Nrf-2/Keap-1 pathway.

Polystyrene microplastics (PS-MPs) are environmental contaminants due to their potential to induce damages in multiple organs specifically liver. Tamarixetin (TMT) is a naturally occurring flavonoid present in Tamarix ramosissima plant that exhibits multiple pharmacological properties. Therefore, the present research was designed to evaluate the palliative role of TMT against PS-MPs instigated liver dysfunction in rats. The exposure to PS-MPs reduced the expressions of nuclear factor erythroid 2-related factor 2and antioxidant genes, while increasing the expression of Kelch-like ECH-associated protein 1. PS-MPs exposed rats exhibited considerably (p < .05) higher alkaline phosphatase (ALP), aspartate aminotransferase (AST) as well as alanine aminotransferase (ALT) contents. Additionally, PS-MPs treatment resulted in a notable decrease in anti-oxidants activity, that is, glutathione S-transferase (GST), superoxide dismutase (SOD), heme oxygenase-1 (HO-1), glutathione reductase (GSR), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH) content, whereas upregulating reactive oxygen species (ROS) and malondialdehyde (MDA) contents. Moreover, PS-MPs intoxication noticeably increased (p < .05) the inflammatory indices (interleukin-1ß [IL-1ß],nuclear factor kappa B [NF-κB], interleukin-6 [IL-6], tumor necrosis factor-α [TNF-α] levels, and cyclooxygenase-2 [COX-2] activity). Besides, Caspase-3 and Bax expressions were upregulated and Bcl-2 expression was decreased after PS-MPs exposure. Additionally, the histomorphological examination revealed notable hepatic damage in PS-MPs treated group. However, TMT treatment substantially (p < .05) recovered all the PS-MPs-induced damages and histopathological changes. Taken together, it can be deduced that TMT might be used as a pharmacological agent to ameliorate hepatic damage.

Dietary Malondialdehyde Damage to the Growth Performance and Digestive Function of Hybrid Grouper (Epinephelus fuscoguttatus♀ × E. lanceolatu♂).

Malondialdehyde (MDA) is the dominant component of lipid peroxidation products. Improper storage and transportation can elevate the lipid deterioration MDA content of diets to values that are unsafe for aquatic animals and even hazardous to human health. The study aimed to investigate the effect of dietary MDA on growth performance and digestive function of hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatu♂). Six isoproteic and isolipidic diets were formulated to contain 0.03, 1.11, 2.21, 4.43, 8.86 and 17.72 mg/kg MDA, respectively. The study shows that the increased dietary MDA content linearly reduced the growth rate, feed utilization, body index and body lipid content of hybrid grouper, while the low dose of dietary MDA (≤2.21 mg/kg) created no difference. Similarly, dietary MDA inclusion linearly depressed the activities of intestinal digestive and absorptive enzymes as well as antioxidant enzymes, enhanced the serum diamine oxidase activity, endotoxin level and intestinal MDA content. A high dose of MDA (≥4.43 mg/kg) generally impaired the gastric and intestinal mucosa, up-regulated the relative expression of Kelch-like ECH-associated protein 1 but down-regulated the relative expression of nuclear factor erythroid 2-related factor 2 in hindgut. In conclusion, the effect of MDA on hybrid grouper showed a dose-dependent effect in this study. A low dose of dietary MDA had limited effects on growth performance and intestinal health of hybrid grouper, while a high concentration damaged the gastrointestinal structure, depressed the intestinal digestive and antioxidant functions, and thereby impaired the growth and health of hybrid grouper.

Cardioprotective effects of plant-based silver nanoparticles: Describing a modern drug

Regarding applicative, facile, green chemical research, a bio-inspired approach is being reported for the synthesis of Ag nanoparticles by Rumex alpinus L as a natural reducing and stabilizing agent without using any toxic and harmful reagent. Our study examined the ability of Ag NPs to make the cardioprotective effects. The biosynthesized Ag NPs@Rumex alpinus L were characterized by advanced physicochemical techniques like ultraviolet–visible (UV–Vis), Fourier Transformed Infrared spectroscopy (FT-IR), and Scanning Electron Microscopy (SEM) study. It has been established that Rumex alpinus L-stabilized silver nanoparticles have a spherical shape with a mean diameter from 12 to 55 nm. In the in medicinal part of this research, four groups of Wister rats were used: a control group; a group treated only with isoproterenol, to induce myocardial infarction; and two groups pretreated with silver nanoparticles containing Rumex alpinus (15 or 45 mg/kg, respectively) for 14 days and challenged with isoproterenol on the 13th and 14th days. Several parameters were measured including cardiac markers, electrocardiogram (ECG), nuclear factor erythroid 2-related factor 2 (Nrf2), the expression of Kelch-like ECH-associated protein 1 (Keap1), and other downstream antioxidant enzymes, as well as the expression of phosphoinositide 3-kinases (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and other downstream apoptotic and inflammatory mediators. Silver nanoparticles containing Rumex alpinus may possess a protective effect against myocardial infarction through moderating myocardial infarction-induced myocardial oxidative stress (GSH, SOD, GPx, GST, and Keap1/Nrf2 pathway), inflammation (IL-1β, IL-6, TNF-α, and NF-κB), apoptosis (caspase-3, caspase-9, Bcl2, and Bax), and autophagy (PI3K/Akt/mTOR pathway). Silver nanoparticles containing Rumex alpinus treatment activated the Keap1/Nrf2/heme oxygenase-1 (HO-1) pathway, increased antioxidant enzyme activities, modulated the PI3K/Akt/mTOR pathway, and ameliorated myocardial autophagy, inflammation, and apoptosis. Silver nanoparticles containing Rumex alpinus treatment reduced the size of the infarct region, attenuated the levels of cardiac indicators, and diminished myocardial necrosis and immune cell infiltration.

Protective Effect of Chinese Bayberry (Myrica rubra Sieb. et Zucc.) Pomace Wine on Oxidative Stress of Hydrogen Peroxide by Regulating Keap1/Nrf2 Pathway in HepG2 Cells.

Chinese bayberry (Myrica rubra Sieb. et Zucc.) pomace wine (CPW) is fruity and rich in bioactive compounds, with high nutritional value and antioxidant activities. This study aims to investigate the protective effect of CPW on the oxidative damage induced by hydrogen peroxide in human hepatocellular carcinoma (HepG2) cells and CPW's possible underlying mechanism. The fluorescence assay results revealed that CPW pre-treatment inhibited intracellular reactive oxygen species (ROS) accumulation in H2O2-induced HepG2 cells and cell membrane injury. Meanwhile, CPW remarkably enhanced the activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and the content of glutathione (GSH). Moreover, CPW pretreatment significantly regulated the expression of Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway-associated genes (Keap1, Nrf2, NADPH quinone oxidoreductase I (NQO1), and heme oxygenase-1 (HO-1)) and its downstream antioxidant genes (SOD, CAT, GSH, and the glutamate-cysteine ligase catalytic (GCLC) subunit) in HepG2 cells. These data demonstrated that CPW prevented H2O2-induced oxidative stress by regulating the Keap1/Nrf2 signaling pathway.

Dietary Histamine Impairs the Digestive Physiology Function and Muscle Quality of Hybrid Grouper (Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂).

An 8-week feeding experiment was conducted to investigate the effect of dietary histamine on growth performance, digestive physiology function and muscle quality in a hybrid grouper (Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂). Seven isoproteic (50%) and isolipidic (11%) diets were prepared with various histamine inclusion levels of 0, 30, 60, 120, 240, 480 and 960 mg/kg in diets (actual contents were 72.33, 99.56, 138.60, 225.35, 404.12, 662.12 and 1245.38 mg/kg), respectively. Each diet was randomly assigned to triplicates of 30 juveniles (average body weight 14.78 g) per tank in a flow-through mariculture system. The increase in the dietary histamine level up to 1245.38 mg/kg made no significant difference on the growth rate and feed utilization of the grouper. However, the increased histamine content linearly decreased the activities of digestive enzymes, while no differences were observed in groups with low levels of histamine (≤404.12 mg/kg). Similarly, high levels of histamine (≥404.12 mg/kg) significantly damaged the gastric and intestinal mucosa, disrupted the intestinal tight junction structure, and raised the serum diamine oxidase activity and endotoxin level. Meanwhile, high doses of histamine (≥662.12 mg/kg) significantly reduced the activities of antioxidant enzymes, upregulated the relative expression of Kelch-like ECH-associated protein 1, and hardened and yellowed the dorsal muscle of grouper. These results showed that dietary histamine was detrimental to the digestive physiology function and muscle quality of the grouper, although it did compromise its growth performance.

Dietary methionine restriction alleviates oxidative stress and inflammatory responses in lipopolysaccharide-challenged broilers at early age.

In this study, we investigated the effect of dietary methionine restriction (MR) on the antioxidant function and inflammatory responses in lipopolysaccharide (LPS)-challenged broilers reared at high stocking density. A total of 504 one-day-old male Arbor Acre broiler chickens were randomly divided into four treatments: 1) CON group, broilers fed a basal diet; 2) LPS group, LPS-challenged broilers fed a basal diet; 3) MR1 group, LPS-challenged broilers fed a methionine-restricted diet (0.3% methionine); and 4) MR2 group, LPS-challenged broilers fed a methionine-restricted diet (0.4% methionine). LPS-challenged broilers were intraperitoneally injected with 1mg/kg body weight (BW) of LPS at 17, 19, and 21days of age, whereas the CON group was injected with sterile saline. The results showed that: LPS significantly increased the liver histopathological score (p < 0.05); LPS significantly decreased the serum total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity at 3h after injection (p < 0.05); the LPS group had a higher content of Interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF)-α, but a lower content of IL-10 than the CON group in serum (p < 0.05). Compared with the LPS group, the MR1 diet increased catalase (CAT), SOD, and T-AOC, and the MR2 diet increased SOD and T-AOC at 3h after injection in serum (p < 0.05). Only MR2 group displayed a significantly decreased liver histopathological score (p < 0.05) at 3h, while MR1 and MR2 groups did so at 8h. Both MR diets significantly decreased serum LPS, CORT, IL-1β, IL-6, and TNF-α contents, but increased IL-10 content (p < 0.05). Moreover, the MR1 group displayed significantly increased expression of nuclear factor erythroid 2-related factor 2 (Nrf2), CAT, and GSH-Px at 3 h; the MR2 group had a higher expression of Kelch-like ECH-associated protein 1 (Keap1), SOD, and GSH-Px at 8h (p < 0.05). In summary, MR can improve antioxidant capacity, immunological stress, and liver health in LPS-challenged broilers. The MR1 and MR2 groups experienced similar effects on relieving stress; however, MR1 alleviated oxidative stress more rapidly. It is suggested that precise regulation of methionine levels in poultry with stress may improve the immunity of broilers, reduce feed production costs, and increase production efficiency in the poultry industry.

Effects of Tributyrin Supplementation on Growth Performance, Intestinal Digestive Enzyme Activity, Antioxidant Capacity, and Inflammation-Related Gene Expression of Large Yellow Croaker (Larimichthys crocea) Fed with a High Level of Clostridium autoethanogenum Protein.

An 8-week growth experiment was conducted to investigate effects of tributyrin (TB) supplementation on growth performance, intestinal digestive enzyme activity, antioxidant capacity, and inflammation-related gene expression of juvenile large yellow croaker (Larimichthys crocea) (initial weight of 12.90 ± 0.02 g) fed diets with high level of Clostridium autoethanogenum protein (CAP). In the negative control diet, 40% fish meal was used as the major source of protein (named as FM), while 45% fish meal protein of FM was substituted with CAP (named as FC) to form a positive control diet. Based on the FC diet, grade levels of 0.05%, 0.1%, 0.2%, 0.4%, and 0.8% tributyrin were added to formulate other five experimental diets. Results showed that fish fed diets with high levels of CAP significantly decreased the weight gain rate (WGR) and specific growth rate (SGR) compared with fish fed the FM diet (P < 0.05). WGR and SGR were significantly higher than in fish fed diets with 0.05% and 0.1% tributyrin that fed the FC diet (P < 0.05). Supplementation of 0.1% tributyrin significantly elevated fish intestinal lipase and protease activities compared to FM and FC diets (P < 0.05). Meanwhile, compared to fish fed the FC diet, fish fed diets with 0.05% and 0.1% tributyrin showed remarkably higher intestinal total antioxidant capacity (T-AOC). Malondialdehyde (MDA) content in the intestine of fish fed diets with 0.05%-0.4% tributyrin was remarkably lower than those in the fish fed the FC diet (P < 0.05). The mRNA expressions of tumor necrosis factor α (tnfα), interleukin-1β (il-1β), interleukin-6 (il-6), and interferon γ (ifnγ) were significantly downregulated in fish fed diets with 0.05%-0.2% tributyrin, and the mRNA expression of il-10 was significantly upregulated in fish fed the 0.2% tributyrin diet (P < 0.05). In regard to antioxidant genes, as the supplementation of tributyrin increased from 0.05% to 0.8%, the mRNA expression of nuclear factor erythroid 2-related factor 2 (nrf2) demonstrated a trend of first rising and then decreasing. However, the mRNA expression of Kelch-like ECH-associated protein 1 (keap1) was remarkably lower in fish fed the FC diet than that fed diets with tributyrin supplementation (P < 0.05). Overall, fish fed tributyrin supplementation diets can ameliorate the negative effects induced by high proportion of CAP in diets, with an appropriate supplementation of 0.1%.

Exosomal hsa-piR1089 promotes proliferation and migration in neuroblastoma via targeting KEAP1.

Neuroblastoma (NB) is a sympathetic nervous system tumor and one of the most common pediatric, extra-cranial, solid tumors, especially in early childhood. Its expression is heterogeneous and shows a unique clinical and prognostic feature. Due to its insidious onset, most diagnoses are accompanied by metastasis, making patient prognoses extremely poor. Novel biomarkers are urgently needed for easy diagnosis, metastasis detection, and investigation of potential mechanisms regulating NB tumor progression. Recent research highlights that circulating tumor markers could be used to diagnose and monitor prognosis in various tumors. Among them, exosomal genetic material has attracted much attention because of its tumor-secreted specificity and unique mechanism of action. In this study, we used next-generation sequencing to study PIWI-interacting RNAs (piRNAs) in exosomes derived from NB patient plasma. We found higher human piRNA 1089 (hsa-piR-1089) levels in exosomes from NB patients than from normal controls. Our receiver operating characteristic (ROC) curve analyses showed that hsa-piR-1089 had high diagnostic sensitivity and specificity. We also found that high hsa-piR-1089 expression in NB tumor tissues was associated with a high-risk Children's Oncology Group classification and metastasis. Our in vitro experiments showed that exosomal hsa-piR-1089 promoted NB cell proliferation and migration by inhibiting Kelch-like ECH-associated protein 1 (KEAP1) expression. Moreover, low KEAP1 expression was associated with NB progression in clinical samples. In conclusion, our data indicate that blood-borne exosomal hsa-piR-1089 is a diagnostic marker for NB and assessing metastasis. Our study provides a quick, simple, and noninvasive diagnostic method for NB and contributes to developing new treatment strategies.

Dietary protein improves flesh quality by enhancing antioxidant ability via the NF-E2-related factor 2/Kelch-like ECH-associated protein 1 signaling pathway in softshell turtle (Pelodiscus sinensis).

An 8-week feeding trial was performed to assess the influence of a gradient of protein levels (14.38-45.23%) on flesh quality, skin color, amino acid profile, collagen, antioxidant capability, and antioxidant-related signaling molecule expression of the softshell turtle (Pelodiscus sinensis). Hardness, gumminess, chewiness, and yellowness values in the plastron and carapace, along with collagen, superoxide dismutase, catalase, total antioxidant capacity, and glutathione peroxidase, all improved with elevating dietary protein up to 26.19%, after which they leveled off. Additionally, total amino acids, flavor amino acids, essential amino acids, and non-essential amino acids in the muscle, as well as the expression of copper/zinc superoxide dismutase, glutathione peroxidase, catalase, manganese superoxide dismutase, NF-E2-related factor 2 were all enhanced by increasing the dietary protein level but not changed by higher protein levels. When dietary protein levels were less than 26.19%, the mRNA expression of Kelch-like ECH-associated protein 1, malondialdehyde, and redness values in the carapace and plastron were reduced, as was the lightness values of the carapace, all of which plateaued at higher protein levels. Using catalase activity and malondialdehyde as the indicators and applying a broken-line analysis, the optimal dietary protein level for P. sinensis was inferred to be 26.07 and 26.06% protein, respectively. In summary, an optimal protein input improved turtle flesh quality by strengthening antioxidant capacity in muscle tissue and by regulating the expression of antioxidant-related enzymes via the Nrf2/keap1 signaling pathway.

Lycopene Affects Intestinal Barrier Function and the Gut Microbiota in Weaned Piglets via Antioxidant Signaling Regulation

In pig production, early and abrupt weaning frequently causes weaning stress, which manifests as oxidative damage, barrier disruption, and digestion and absorption capacity declines. Lycopene exhibits beneficial antioxidant capacity in both humans and other animal models. The present study aimed to investigate the effects of lycopene supplementation on early weaning stress in piglets and the underlying mechanisms by examining the oxidative stress state, gut intestinal barrier function, and the gut microbiota. Twenty-four 21-day-old weaned piglets [Duroc × (Landrace × Yorkshire); castrated males; 5.48 ± 0.10 kg initial body weight] were randomly assigned to 2 treatments. The piglets were fed a basal diet (control treatment) or a basal diet supplemented with 50 mg/kg lycopene (lycopene treatment) for 28 days. The serum lipid levels, serum and jejunum enzyme activities, jejunum morphology, mRNA and protein expression, and gut microbiota were determined. Compared with the control treatment, lycopene supplementation increased the serum catalase activity (P = 0.042; 62.0%); serum total cholesterol concentration (P = 0.020; 14.1%); and jejunum superoxide dismutase activity (P = 0.032; 21.4%), whereas it decreased serum (P = 0.039, 23.0%) and jejunum (P = 0.047; 20.9%) hydrogen peroxide concentrations. Additionally, lycopene increased the mRNA and protein expression of NFE2-like bZIP transcription factor 2 (214.0% and 102.4%, respectively) and CD36 (100.8% and 145.2%, respectively) in the jejunum, whereas it decreased the mRNA and protein expression of Kelch-like ECH-associated protein 1 (55.6% and 39.8%, respectively ). Lycopene also improved jejunal morphology, increasing the villus height (P = 0.018; 27.5%) and villus:crypt ratio (P < 0.001; 57.9%). Furthermore, it increased the abundances of potentially beneficial bacterial groups, including Phascolarctobacterium and Parasutterella, and decreased those of potentially pathogenic bacterial groups, including Treponema_2 and Prevotellaceae_unclassified. Lycopene supplementation strengthens the intestinal barrier function and improves the gut microbiota in weaned piglets by regulating intestinal antioxidant signaling.

Effects of Total Flavonoids of Artemisia ordosica on Growth Performance, Oxidative Stress, and Antioxidant Status of Lipopolysaccharide-Challenged Broilers.

Artemisia ordosica has been applied as a traditional Chinese/Mongolian medicine for the treatment of certain inflammatory ailments. This study was conducted to investigate the effect of Artemisia ordosica total flavonoids (ATF) supplemented in diets on growth performance, oxidative stress, and antioxidant status in lipopolysaccharide (LPS)-challenged broilers. A total of 240 one-day-old Arbor Acre broilers were randomly allotted into 5 groups with 6 replicates (n = 8), which were the basal diet group (CON), LPS-challenged and basal diet group (LPS), and the LPS-challenged and basal diet added with low (500 mg/kg), middle (750 mg/kg), and high (1000 mg/kg) doses of ATF groups (ATF-L, ATF-M, and ATF-H), respectively. On day 16, 18, 20, 22, 24, 26, and 28, broilers were injected intra-abdominally either with LPS or an equivalent amount of saline. Results showed that dietary ATF alleviated the LPS-induced decrease in BW, ADG, and ADFI in broilers. Dietary ATF supplementation reversed the increased serum oxidative damage indexes (reactive oxygen species, protein carbonyl, and 8-hydroxy-2-deoxyguanosine) and the decreased serum antioxidant indexes [total superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and total antioxidant capacity (TAC)] in LPS-challenged broilers. Moreover, ATF alleviated the decreased antioxidase activity and the over-production of malondialdehyde (MDA) in the liver and spleen induced by LPS. This study also showed that ATF alleviated the increased mRNA expression of Kelch-like ECH-associated protein 1 (Keap1) and the decreased mRNA expression of nuclear factor erythroid 2-related factor 2 (Nrf2), CAT, SOD, and GPx in the liver and spleen of broilers challenged with LPS. In conclusion, ATF has a strong capacity to enhance antioxidant enzyme activity and relieve oxidative stress and can be used as a potential novel feed additive in poultry diets to improve growth performance and antioxidant capacity.