Copper-zinc Superoxide Dismutase Research Articles

Elevated Renal Oxidative Stress and Na+ Transporters are Associated with Hypertension in Postpartum Preeclamptic Rats

Background: Approximately 5-10% of US pregnancies result in preeclampsia (PE). PE is characterized by new onset hypertension (HTN) during pregnancy and is usually accompanied by end-organ damage, especially in the kidneys. Postpartum (PP) women and dams that had PE have an increased risk of developing HTN and chronic kidney disease (CKD) later in life. However, mechanisms linking PE to the long-term development of HTN and CKD are unknown. One aspect that may contribute to renal injury in PP PE women and dams is oxidative stress. Elevated concentrations of oxidative stress have been shown to augment the abundance and activity of renal transporters to increase sodium (Na+) reabsorption and blood volume. These alterations in renal transporters can consequently increase Na+ and water to facilitate HTN. Thus, we hypothesize that at 6 weeks PP (~3 human years), PE dams will display increased oxidative stress, renal Na+ transporter abundance, and elevated blood pressure (BP). Methods: Pregnant Sprague Dawley rats were randomly assigned to two groups: normal (CON) and PE dams. On gestational day 14, the reduced uterine perfusion pressure surgery was performed to mimic placental ischemia and generate a model of PE. Dams gave birth naturally and weaned for 3 weeks. After 6 weeks PP, BP was measured via carotid catheterization, and kidneys were removed and sectioned. Western blots were used to quantify renal Na+ transporters: Na+ K+ 2Cl− transporter (NKCC2) in the kidney medulla (KM) and epithelial Na+ channel (ENaC) in both the kidney cortex (KC) and KM. Oxidative stress was evaluated by heat shock protein 1 (HSP-1), copper zinc superoxide dismutase (CuZnSOD), and manganese superoxide dismutase (MnSOD) via Western blots. Hydrogen peroxide (H2O2) and antioxidant capacity concentrations were assessed via colorimetric assays. Results: PP PE dams had increased BP (126.3±6.18vs105.7±3.74 mmHg, p<0.05) at 6 weeks after birth. KC HSP-1, H2O2, MnSOD, and antioxidant capacity were unchanged between groups. However, KC CuZnSOD protein abundance was decreased in PP PE dams (69.51±11.64vs100±5.73 IU/Protein/Control%, p<0.05). In the KM, HSP-1 abundance (113.7±3.3vs100±5.07 IU/Protein/Control%, p=0.06) and H2O2 concentrations (1.97±0.11vs1.31± 0.38 nM H2O2/mg Protein, p=0.08) were elevated in PP PE dams. MnSOD, CuZnSOD, and antioxidant capacity were unchanged between groups in the KM. No changes occurred in KC and KM ENaC protein abundance. However, NKCC2 protein abundance was elevated by ~50% in PP PE dams (151.71±22.17vs100±5.59 IU/Protein/Control%, p=0.06). Conclusion: In summary, BP, oxidative stress, and NKCC2 were elevated in PP PE dams at 6 weeks. Perhaps, the presence of oxidative stress in the KM may lead to increased NKCC2 abundance. However, more studies are warranted to make this conclusion. NKCC2 elevation may result in increased Na+ and water reabsorption, leading to an increase in BP. Future studies will assess the role of renal oxidative stress to regulate Na+ transporters in PP PE dams and determine the timeline after birth (PP) in which changes in oxidative stress, Na+ transporters, and BP occur. In summary, this study is clinically relevant because it indicates that both oxidative stress and NKCC2 in the KM, separately or together, may have a formative role in the pathogenesis of HTN and CKD in PP PE women later in life. This research was supported by the Neurobiology of Aging and Alzheimer’s Disease Training Program (funded by NIH training grant T32 AG020494). 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.

Electrochemical biosensing platform based on AuNWs/rGO-CMC-PEDOT:PSS composite for the detection of superoxide anion released from living cells

Detection of superoxide anion (O2·-) levels holds significant importance for the diagnosis and even clinical treatments of oxidative stress-related diseases. Herein, we prepared a composite electrode material to encapsulate copper-zinc superoxide dismutase (SOD1) for biosensing of O2·-. The sensing material consists of gold nanowires (AuNWs), reduced graphene oxide (rGO), carboxymethyl cellulose (CMC) and PEDOT:PSS. CMC provides abundant -COOH to bind SOD1, with a high adsorption coverage of 1.499 × 10−9 mol cm−2 on the sensor surface. rGO and PEDOT endow the composite with significant conductivity, whereas PSS has antifouling capability. Moreover, AuNWs exhibit excellent electrical conductivity and a high aspect ratio, which promotes electron transfer, and ultimately enhances the catalytic performance of the enzyme. Meanwhile, SOD1(Cu2+) catalyzes the dismutation of O2·- to O2 and H2O2, and H2O2 is then electrochemically oxidized to generate amperometric signals for determination of O2·-. The sensor demonstrates outstanding detection performance for O2·- with a low detection limit of 2.52 nM, and two dynamic ranges (14.30 nM–1.34 μM and 1.34 μM–42.97 μM) with corresponding sensitivity of 0.479 and 0.052 μA μM−1cm−2, respectively. Additionally, the calculated apparent Michaelis constant (Kmapp) of 1.804 μM for SOD1 demonstrates the outstanding catalytic activity and the surface-immobilized enzyme's substrate affinity. Furthermore, the sensor shows the capability to dynamically detect the level of O2·- released from living HepG2 cells. This study provides an inovative design to obtain a biocompatible electrochemical sensing platform with plenty of immobilization sites for biomolecules, large surface area, high conductivity and flexibility.

Semirational Design Based on Consensus Sequences to Balance the Enzyme Activity-Stability Trade-Off.

In this study, the phenomenon of the stability-activity trade-off, which is increasingly recognized in enzyme engineering, was explored. Typically, enhanced stability in enzymes correlates with diminished activity. Utilizing Rosa roxburghii copper-zinc superoxide dismutase (RrCuZnSOD) as a model, single-site mutations were introduced based on a semirational design derived from consensus sequences. The initial set of mutants was selected based on activity, followed by combinatorial mutation. This approach yielded two double-site mutants, D25/A115T (18,688 ± 206 U/mg) and A115T/S135P (18,095 ± 1556 U/mg), exhibiting superior enzymatic properties due to additive and synergistic effects. These mutants demonstrated increased half-lives (T1/2) at 80 °C by 1.2- and 1.6-fold, respectively, and their melting temperatures (Tm) rose by 3.4 and 2.5 °C, respectively, without any loss in activity relative to the wild type. Via an integration of structural analysis and molecular dynamics simulations, we elucidated the underlying mechanism facilitating the concurrent enhancement of both thermostability and enzymatic activity.

Current potential pathogenic mechanisms of copper-zinc superoxide dismutase 1 (SOD1) in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease which damages upper and lower motor neurons (UMN and LMN) innervating the muscles of the trunk, extremities, head, neck and face in cerebrum, brain stem and spinal cord, which results in the progressive weakness, atrophy and fasciculation of muscle innervated by the related UMN and LMN, accompanying with the pathological signs leaded by the cortical spinal lateral tract lesion. The pathogenesis about ALS is not fully understood, and no specific drugs are available to cure and prevent the progression of this disease at present. In this review, we reviewed the structure and associated functions of copper-zinc superoxide dismutase 1 (SOD1), discuss why SOD1 is crucial to the pathogenesis of ALS, and outline the pathogenic mechanisms of SOD1 in ALS that have been identified at recent years, including glutamate-related excitotoxicity, mitochondrial dysfunction, endoplasmic reticulum stress, oxidative stress, axonal transport disruption, prion-like propagation, and the non-cytologic toxicity of glial cells. This review will help us to deeply understand the current progression in this field of SOD1 pathogenic mechanisms in ALS.

Dual-Site Biomimetic Cu/Zn-MOF for Atopic Dermatitis Catalytic Therapy via Suppressing FcγR-Mediated Phagocytosis.

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease that carries a significant global economic burden. Elevated levels of reactive oxygen species (ROS) have been recognized as contributing to AD exacerbation, making them a potential therapeutic target for AD treatment. Here, we introduce a dual-site biomimetic copper/zinc metal-organic framework (Cu/Zn-MOF) featuring four types of enzyme-like activities for AD treatment via suppressing the Fcγ receptor (FcγR)-mediated phagocytosis signal by mimicking the bimetallic sites of natural copper-zinc superoxide dismutase (CuZn-SOD). Interestingly, the neighboring Cu and Zn sites in both Cu/Zn-MOF and CuZn-SOD are at similar distances of ∼5.98 and ∼6.3 Å from each other, respectively, and additionally, both Cu and Zn sites are coordinated to nitrogen atoms in both structures, and the coordinating ligands to Cu and Zn are both imidazole rings. Cu/Zn-MOF exhibits remarkable SOD-like activity as well as its glutathione peroxidase (GPx)-, thiol peroxidase (TPx)-, and ascorbate peroxidase (APx)-like activities to continuously consume ROS and mitigate oxidative stress in keratinocytes. Animal experiments show that Cu/Zn-MOF outperforms halcinonide solution (a potent steroid medication) in terms of preventing mechanical injuries, reducing cutaneous water loss, and inhibiting inflammatory responses while presenting favorable biosafety. Mechanistically, Cu/Zn-MOF functions through an FcγR-mediated phagocytosis signal pathway, decreasing the continuous accumulation of ROS in AD and ultimately suppressing disease progression. These findings will provide an effective paradigm for AD therapy and contribute to the development of two-site bionics (TSB).

Olanzapine Effects on Parvalbumin/GAD67 Cell Numbers in Layers/Subregions of Dorsal Hippocampus of Chronically Socially Isolated Rats.

Depression is linked to changes in GABAergic inhibitory neurons, especially parvalbumin (PV) interneurons, which are susceptible to redox dysregulation. Olanzapine (Olz) is an atypical antipsychotic whose mode of action remains unclear. We determined the effect of Olz on PV-positive (+) and glutamate decarboxylase 67 (GAD67) + cell numbers in the layers of dorsal hippocampus (dHIPP) cornu ammonis (CA1-CA3) and dentate gyrus (DG) subregions in rats exposed to chronic social isolation (CSIS), which is an animal model of depression. Antioxidative enzymes and proinflammatory cytokine levels were also examined. CSIS decreased the PV+ cell numbers in the Stratum Oriens (SO) and Stratum Pyramidale (SP) of dCA1 and dDG. It increased interleukin-6 (IL-6), suppressor of cytokine signaling 3 (SOCS3), and copper-zinc superoxide dismutase (CuZnSOD) levels, and it decreased catalase (CAT) protein levels. Olz in CSIS increased the number of GAD67+ cells in the SO and SP layers of dCA1 with no effect on PV+ cells. It reduced the PV+ and GAD67+ cell numbers in the Stratum Radiatum of dCA3 in CSIS. Olz antagonizes the CSIS-induced increase in CuZnSOD, CAT and SOCS3 protein levels with no effect on IL-6. Data suggest that the protective Olz effects in CSIS may be mediated by altering the number of PV+ and GAD67+ cells in dHIPP subregional layers.

Direct relationship between dimeric form and activity in the acidic copper-zinc superoxide dismutase from lemon.

The copper-zinc superoxide dismutase (CuZnSOD) from lemon (SOD_CL) is active in an acidic environment and resists proteolytic degradation. The enzyme occurs as a dimer, which has an indirect effect on the enzyme activity as the monomer retains only ∼35% of the activity. Here, the crystal structure of SOD_CL at 1.86 Å resolution is reported that may explain this peculiarity. Thecrystal belonged to space group P21, with unit-cell parameters a = 61.11, b=74.55, c = 61.69 Å, β = 106.86°, and contained four molecules in the asymmetric unit. The overall structure of SOD_CL resembles that of CuZnSOD from plants. The structure of SOD_CL shows a unique arrangement of surface loop IV that connects the dimer interface and the active site, which is located away from the dimer-interface region. This arrangement allows direct interaction between the residues residing in the dimer interface and those in the active site. The arrangement also includes Leu62 and Gln164, which are conserved in cytoplasmic CuZnSOD. This supports the classification of SOD_CL as a cytoplasmic CuZnSOD despite sharing the highest amino-acid sequence homology with CuZnSODs from spinach and tomato, which are chloroplastic.

Extreme diversity of 12 cations in folding ALS-linked hSOD1 unveils novel hSOD1-dependent mechanisms for Fe2+/Cu2+-induced cytotoxicity

153-Residue copper-zinc superoxide dismutase 1 (hSOD1) is the first gene whose mutation was linked to FALS. To date, > 180 ALS-causing mutations have been identified within hSOD1, yet the underlying mechanism still remains mysterious. Mature hSOD1 is exceptionally stable constrained by a disulfide bridge to adopt a Greek-key β-barrel fold that accommodates copper/zinc cofactors. Conversely, nascent hSOD1 is unfolded and susceptible to aggregation and amyloid formation, requiring Zn2+ to initiate folding to a coexistence of folded and unfolded states. Recent studies demonstrate mutations that disrupt Zn2+-binding correlate with their ability to form toxic aggregates. Therefore, to decode the role of cations in hSOD1 folding provides not only mechanistic insights, but may bear therapeutic implications for hSOD1-linked ALS. Here by NMR, we visualized the effect of 12 cations: 8 essential for humans (Na+, K+, Ca2+, Zn2+, Mg2+, Mn2+, Cu2+, Fe2+), 3 mimicking zinc (Ni2+, Cd2+, Co2+), and environmentally abundant Al3+. Surprisingly, most cations, including Zn2+-mimics, showed negligible binding or induction for folding of nascent hSOD1. Cu2+ exhibited extensive binding to the unfolded state but led to severe aggregation. Unexpectedly, for the first time Fe2+ was deciphered to have Zn2+-like folding-inducing capacity. Zn2+ was unable to induce folding of H80S/D83S-hSOD1, while Fe2+ could. In contrast, Zn2+ could trigger folding of G93A-hSOD1, but Fe2+ failed. Notably, pre-existing Fe2+ disrupted the Zn2+-induced folding of G93A-hSOD1. Comparing with the ATP-induced folded state, our findings delineate that hSOD1 maturation requires: (1) intrinsic folding capacity encoded by the sequence; (2) specific Zn2+-coordination; (3) disulfide formation and Cu-load catalyzed by hCCS. This study unveils a previously-unknown interplay of cations in governing the initial folding of hSOD1, emphasizing the pivotal role of Zn2+ in hSOD1-related ALS and implying new hSOD1-dependent mechanisms for Cu2+/Fe2+-induced cytotoxicity, likely relevant to aging and other diseases.

Copper-Zinc Superoxide Dismutase (CuZn-SOD) Electrochemical Catalytic Amplification Sensing at Pt Ultramicroelectrodes

Abstract. Copper/zinc superoxide dismutase (CuZnSOD), a 32.5 kDa metalloprotein with a radius of ca. 2.1 nm, catalyses the superoxide to hydrogen peroxide and molecular oxygen. At the femtomolar concentration range, has been sensed through electrochemical catalytic amplification using a Pt ultramicroelectrode. During amperometric (i vs. t) analysis, cathodic and anodic current transitions peaks were seen, in agreement with the metalloprotein catalytic mechanism. The current amplitudes were analyzed and correspond to the CuZnSOD dimensions. Thermal treatment of metalloprotein samples at 80 °C showed larger current spikes suggesting aggregation without losing its catalytic capability. The size was confirmed by transmission electron microscopy. Resumen. Cuprozinc superóxido dismutasa (CuZnSOD), es una metaloproteina de 32.5 kDa con un radio de aproximadamente 2.1 nm. Esta enzima cataliza la reacción de superóxido a peróxido y oxígeno molecular. Por primera vez, esta proteína es detectada a concentraciones femtomolares haciendo uso de la técnica electroquímica conocida como amplificación catalítica y la tecnología de ultra-microelectrodos de Pt. Durante un análisis amperométrico (curvas i vs. t), se observaron picos transitorios de corriente catódica y anódica que concuerdan con el mecanismo catalítico de la enzima. Al analizar la amplitud de la corriente, la misma concuerda con las dimensiones de CuZnSOD. Luego de exponer la proteína a un tratamiento térmico de 80 °C, CuZnSOD mostró picos de corriente transitorias que sugieren aglomeración de la enzima sin perder su capacidad catalítica. El tamaño fue confirmado por microscopía electrónica de transmisión.

The miRNA-mRNA Regulatory Modules of Pinus massoniana Lamb. in Response to Drought Stress.

Masson pine (Pinus massoniana Lamb.) is a major fast-growing woody tree species and pioneer species for afforestation in barren sites in southern China. However, the regulatory mechanism of gene expression in P. massoniana under drought remains unclear. To uncover candidate microRNAs, their expression profiles, and microRNA-mRNA interactions, small RNA-seq was used to investigate the transcriptome from seedling roots under drought and rewatering in P. massoniana. A total of 421 plant microRNAs were identified. Pairwise differential expression analysis between treatment and control groups unveiled 134, 156, and 96 differential expressed microRNAs at three stages. These constitute 248 unique microRNAs, which were subsequently categorized into six clusters based on their expression profiles. Degradome sequencing revealed that these 248 differentially expressed microRNAs targeted 2069 genes. Gene Ontology enrichment analysis suggested that these target genes were related to translational and posttranslational regulation, cell wall modification, and reactive oxygen species scavenging. miRNAs such as miR482, miR398, miR11571, miR396, miR166, miRN88, and miRN74, along with their target genes annotated as F-box/kelch-repeat protein, 60S ribosomal protein, copper-zinc superoxide dismutase, luminal-binding protein, S-adenosylmethionine synthase, and Early Responsive to Dehydration Stress may play critical roles in drought response. This study provides insights into microRNA responsive to drought and rewatering in Masson pine and advances the understanding of drought tolerance mechanisms in Pinus.

Effects of dietary tributyrin supplementation in low fish meal diet containing high-Clostridium autoethanogenum protein on the growth performance, antioxidative capacity, lipid metabolism and intestinal microbiota of largemouth bass (Micropterus salmoides)

This study aimed to investigate the impact of dietary tributyrin (TB) in the low fish meal (high-Clostridium autoethanogenum protein, CAP) diet on the growth, antioxidation, lipid metabolism and intestinal microbiota of largemouth bass (Micropterus salmoides). For eight weeks, largemouth bass (15.05 ± 0.58 g) were fed on eight isonitrogenous and isolipid diets with graded levels of dietary TB (0 g/kg, 0.2 g/kg, 0.4 g/kg, 0.8 g/kg, 1.6 g/kg, 3.2 g/kg, 4.0 g/kg and 8.0 g/kg). The findings showed that the weight gain rate (WGR) and specific growth rate (SGR) were increased by 1.6 g/kg of dietary TB. The protein efficiency and deposition ratios were linearly affected by dietary TB. The broken-line model based on the WGR revealed that 1.617 g/kg of dietary TB was sufficient for optimal growth. The digestive enzyme activities and villus length of the intestine were increased by dietary TB (1.6 g/kg). Total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and catalase (CAT) activities were significantly improved, and the malondialdehyde (MDA) and protein carbonyl (PC) contents were significantly decreased after dietary TB. The expressions of nuclear factor erythroid 2-related factor 2 (nrf2) and kelch like ech associated protein 1 (keap1) in the liver and intestine were significantly increased and decreased by 1.6 g/kg of dietary TB, respectively. The mRNA levels of copper-zinc superoxide dismutase (cuznsod), cat, heme oxygenase-1 (ho-1) and glutathione peroxidase (gpx) were significantly upregulated. Dietary TB could significantly affect the total protein (TP) and albumin (ALB) content in the serum. The aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were the lowest at 1.6 g/kg of TB group. Besides, the hepatocyte vacuolation and nuclear translocation were alleviated after supplementation of 0.2‰− 3.0‰ of dietary TB. The total cholesterol (T-CHO), high density lipoprotein cholesterol (HDLC) and low density lipoprotein cholesterol (LDLC) were significantly increased by dietary TB. The triglycerides (TG) content was decreased by dietary TB. The mRNA levels of sterol regulatory element-binding protein 1-c (srebp1-c), acetyl-coa carboxylase alpha (accα), fatty acid synthase (fasn) and accβ in the liver were significantly downregulated, and peroxisome proliferator-activated receptor alpha (pparα) and carnitine palmitoyltransferase 1 (cpt-1) were upregulated by 1.6 g/kg of dietary TB. Dietary TB had effects on the intestine microbes of largemouth bass. The Cetobacterium was present in the highest percentage and increased from 41% (0 g/kg TB) to 59% (1.6 g/kg TB). The Mycoplasmataceae was the second most predominant genus and decreased from 90% in the 0 g/kg of TB group to 10% in the 1.6 g/kg of TB group. In summary, the dietary TB could be supplemented in the CAP-based diet for better growth and antioxidation, lipid metabolism and intestinal microbiota of largemouth bass.

Abstract P420: Changes In Cardiac Oxidative Stress Is Protected In Intrauterine Growth Restricted Females Vs Males Before The Development Of Hypertension And Cardiovascular Diseases

Preeclampsia (PE) is a pregnancy complication characterized by hypertension (HTN) typically during the third trimester. PE is the leading cause for intrauterine growth restricted (IUGR) offspring (OFS). Women with PE and their OFS (IUGR) are at a higher risk for developing cardiovascular diseases (CVD) later in life. Two major factors that contribute to the development of CVDs are HTN and oxidative stress (OS). Studies show that human and animals adult IUGR OFS have a higher risk of developing HTN and CVDs compared to females later in life. The rationale for these sex differences is unknown; and we hypothesize that male IUGR rats will have elevated cardiac oxidative stress, while female IUGR will have lower cardiac OS .To test, we will examine sex differences between 12 week IUGR and control (CON) OFS that are not hypertensive, to determine if there are any change in cardiac OS before the development of HTN and CVD. Methods: Sprague Dawley rats were divided into 4 groups: IUGR male, IUGR female, and control (CON) male and female. IUGR rats were derived from the OFS reduced uterine perfusion pressure (RUPP) PE rat model. CON OFS were from normal pregnant rats. At 12wk, BP was measured via carotid catheterization. Heart tissue was collected to assess oxidative stress, via examining reactive oxygen species (ROS) Heat shock protein 1 (HSP-1) and hydrogen peroxide (H2O2). Antioxidants were measured via manganese superoxide dismutase (MnSOD), copper zinc superoxide dismutase (CuZnSOD) and antioxidant capacity (AC). There were no significant changes in HSP-1, CuZnSOD, and H2O2 between male and female OFS. However, female IUGR OFS had a 20% increase in antioxidant MnSOD (119.9 ± 6.133 vs 93.98 ± 5.197 %MnSOD U/protein/CON, p <0.05) compared to CON in the heart. Male OFS had no significant changes for MnSOD. IUGR female AC had a 2-fold increase in activity (22.13 ± 1.019 vs 14.15 ± 1.852 mM Trolox/mg protein, p <0.05) compared to its CON. Furthermore, IUGR male OFS had a slight decrease in AC compared to CON male (11.00 ± 1.420 vs 13.24 ± 0.4676 mM Trolox/mg protein, ns). The significant increase of AC and MnSOD in IUGR female OFS suggests that females may be more protected from OS, via mitochondria-specific antioxidants compared to males.

Zinc Supplementation Reduces Testicular Cell Apoptosis in Mice and Improves Spermatogenic Dysfunction Caused by Marginal Zinc Deficiency.

Zinc (Zn) is an important trace element in the human body and plays an important role in growth, development, and male reproductive functions. Marginal zinc deficiency (MZD) is common in the human population and can cause spermatogenic dysfunction in males. Therefore, the aim of this study was to investigate methods to improve spermatogenic dysfunction caused by MZD and to further explore its mechanism of action. A total of 75 4-week-old male SPF ICR mice were randomly divided into five groups (control, MZD, MZD + ZnY2, MZD + ZnY4, and MZD + ZnY8, 15 mice per group). The dietary Zn content was 30mg/kg in the control group and 10mg/kg in the other groups. From low to high, the Zn supplementation doses administered to the three groups were 2, 4, and 8mg/kg·bw. After 35days, the zinc content, sperm quality, activity of spermatogenic enzymes, oxidative stress level, and apoptosis level of the testes in mice were determined. The results showed that MZD decreased the level of Zn in the serum, sperm quality, and activity of spermatogenic enzymes in mice. After Zn supplementation, the Zn level in the serum increased, sperm quality was significantly improved, and spermatogenic enzyme activity was restored. In addition, MZD reduced the content of antioxidants (copper-zinc superoxide dismutase (Cu-Zn SOD), metallothionein (MT), and glutathione (GSH) and promoted malondialdehyde (MDA) production. The apoptosis index of the testis also increased significantly in the MZD group. After Zn supplementation, the level of oxidative stress decreased, and the apoptosis index in the testis was reduced. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) showed that the expression of B-cell lymphoma-2 (Bcl-2) mRNA and Bcl-2/BCL2-associated X (Bax) in the control group decreased in testicular cells, and their expression was restored after Zn supplementation. The results of this study indicated that Zn supplementation can reduce the level of oxidative stress and increase the ability of testicular cells to resist apoptosis, thereby improving spermatogenic dysfunction caused by MZD in mice.

CYP2E1 triggered GRP78/ATF6/CHOP signaling axis inhibit apoptosis and promotes progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide. Cytochrome P450 2E1 (CYP2E1) is an enzyme, primarily involved in the metabolism of xenobiotics and procarcinogens. The present study was designed to investigate the potential role of CYP2E1 triggered endoplasmic reticulum stress in the progression of HCC through inhibition of apoptosis. In vitro CYP2E1 promotes HepG2 cell migration, reduced chromatin condensation, enhanced intracellular ROS accumulation and induce cell cycle progression. Conversely this effect was averted by CYP2E1 siRNA, selective inhibitor Diallyl sulphide (DAS) and antioxidants (vitamin C and E). In vivo Diethylnitrosamine (DEN) induced HCC rats showed decreased body weight and increased relative liver weight. Moreover, macro trabecular-massive HCC (MTM-HCC) histological subtyping showed pathological features like well-differentiated tumors, micro-trabecular and pseudo glandular patterns, megakaryocytes and cholestasis. Masson's trichrome staining revealed an intensive accumulation of collagen fibers in the extracellular matrix (ECM). Increased CYP2E1, VEGF and PCNA enhance the carcinogenicity as revealed in immunohistochemistry results. Immunoblot analysis showed reduced expression of copper-zinc superoxide dismutase (CuZnSOD) and manganese superoxide dismutase (MnSOD) in cytosolic as well as mitochondrial fraction of rat liver tissue respectively. Also, increased level of CYP2E1 stimulated the upregulation of unfolded proteins response (UPR) and ER stress-related proteins such as Glucose regulatory protein 78 (GRP78), activating transcription factor 6 (ATF6) and CCAAT enhancer-binding protein (C/EBP) homologous protein (CHOP). Meanwhile, CYP2E1 stimulated ER-stress reduces BCL2 and downregulates the cleaved caspase 3 thus suppresses apoptosis. in. Furthermore, immunofluorescence revealed increased expression level of α-SMA in the HCC rat liver tissue. The level of CYP2E1 mRNA was significantly increased. Altogether, these findings indicate that CYP2E1 has a dynamic role in the pathogenesis of HCC and might be a budding agent in liver carcinogenesis therapy.

Characterization of a Novel Superoxide Dismutase from a Deep-sea Sea Cucumber (Psychoropotes verruciaudatus).

At present, deep-sea enzymes are a research hotspot. In this study, a novel copper-zinc superoxide dismutase (CuZnSOD) was successfully cloned and characterized from a new species of sea cucumber Psychropotes verruciaudatus (PVCuZnSOD). The relative molecular weight of the PVCuZnSOD monomer is 15 kDa. The optimum temperature of PVCuZnSOD is 20 °C, and it maintains high activity in the range of 0-60 °C. It also has high thermal stability when incubated at 37 °C. PVCuZnSOD has a maximum activity of more than 50% in the pH range of 4-11 and a high activity at pH 11. In addition, PVCuZnSOD has strong tolerance to Ni2+, Mg2+, Ba2+, and Ca2+, and it can withstand chemical reagents, such as Tween20, TritonX-100, ethanol, glycerol, isopropanol, DMSO, urea, and GuHCl. PVCuZnSOD also shows great stability to gastrointestinal fluid compared with bovine SOD. These characteristics show that PVCuZnSOD has great application potential in medicine, food, and other products.

Dietary zinc supplementation in breeding pigeons improves the carcass traits of squabs through regulating antioxidant capacity and myogenic regulatory factor expression

The purpose of this experiment was to explore the effects of zinc supplementation in breeding pigeons diet on carcass traits, meat quality, antioxidant capacity and mRNA expressions of myogenic regulatory factors of squabs. A total of 120 healthy White King pigeons were randomly assigned to 5 treatments, each involving 8 replicates. The experiment lasted for 46 d (18-d incubation period of eggs and 28-d growth period of squabs). The 5 groups were 0, 30, 60, 90, and 120 mg/kg zinc addition. Results showed that the 28-d body weight, breast muscle yield, zinc content in crop milk and myogenic factor 6 (MyF6) abundance of breast muscle were linearly increased (P < 0.050), but the abdominal fat yield linearly decreased (P=0.040) with increasing dietary zinc supplementation. Both the linear (P < 0.050) and quadratic responses (P < 0.001) were observed in copper zinc superoxide dismutase (Cu-Zn SOD), total antioxidant capacity (T-AOC) and malondialdehyde (MDA) contents in liver and breast muscle. The 28-d body weight was increased by 90 mg/kg zinc supplementation (P < 0.05), and there is no significant difference between 90 and 120 mg/kg zinc addition. The breast muscle yield, Cu-Zn SOD and T-AOC contents in breast muscle and liver, zinc contents in crop milk and breast muscle, MyF6 mRNA expression in breast muscle were higher (P < 0.05) in the group supplemented with 120 mg/kg zinc than the control. The abdominal fat yield was numerically lowest, and MDA contents in breast muscle and liver were significantly lowest in the group fed 120 mg/kg zinc (P < 0.05). However, the meat quality traits were not affected (P > 0.05) by zinc supplementation, except for shear force. It should be stated dietary zinc supplementation at the level of 120 mg/kg for breeding pigeons increased body weight and breast muscle yield of squabs, which may be associated with the up-regulating MyF6 mRNA expression and antioxidant capacity in liver and breast muscle.

In vitro anticancer and antimicrobial activities of copper-zinc superoxide dismutase purified from Cellana rota snail

In vitro anticancer and antimicrobial activities of copper-zinc superoxide dismutase purified from Cellana rota snail

Exercise for myocardial ischemia-reperfusion injury: A systematic review and meta-analysis based on preclinical studies.

The main pathological manifestation of coronary artery disease is myocardial injury caused by ischemia-reperfusion (IR) injury. Regular exercise reduces the risk of death during myocardial IR injury. The aim of this study was to describe the effects of various types of exercise on myocardial IR injury. Four electronic databases PubMed, Web of Science, Embase, and Cochrane Library were comprehensively searched from inception until February 2022, to identify studies relevant to the current review, using the method of combining subject and free words. Finally, 16 articles were included in the meta-analysis. Results showed that exercise training decreases the Myocardial infarct size compared to the control group (SMD=-2.6, 95% CI [-3.53 to -1.67], P<0.01); increasing the coronary blood flow (MD=2.93, 95% CI [2.41 to 3.44], P<0.01), left ventricular developed pressure (SMD=2.28, 95% CI [0.12 to 4.43], P<0.05), cardiac output (SMD=1.22, 95% CI [0.61 to 1.83], P<0.01) compared to the control group. According to the descriptive analysis results also showed that exercise training increases the left ventricular ejection fraction, superoxide dismutase, manganese superoxide dismutase, glutathione peroxidase, copper-zinc superoxide dismutase, glutathione peroxidase, and decrease the creatine kinase, creatine kinase-MB, lactate dehydrogenase, Malondialdehyde, cardiac troponins T. Exercise can improve myocardial function after myocardial IR injury; however, further research is needed in combination with specific issues such as exercise mode, intensity, duration, and model issues.

Lack of Sod1 induces disruption of innervation accompanied by Schwann cell proliferation in skeletal muscle

The neuromuscular junction (NMJ) is an excitatory synapse that constitutes the primary site of communication between the nervous system and skeletal muscle and therefore any degenerative changes at the NMJ have the potential to impair muscle function. The primary cellular components of the NMJ are the motor neuron, the muscle fiber and terminal Schwann cells (tSC) that surround the NMJ. The importance of redox homeostasis for the maintenance of NMJ integrity is supported by work from our group showing degenerative changes at NMJs in mice lacking copper zinc superoxide dismutase (CuZnSOD; Sod1 -/- ) as early as 4 months of age. Prior work from others suggests that tSCs contribute trophic support for the NMJ and facilitate motor unit remodeling, but changes in tSC structure and function under conditions of elevated oxidative stress have not been thoroughly explored. Using in vitro assays, we previously showed that primary Schwann cells treated with a sublethal dose of the reactive oxygen species inducing agent Paraquat (PQ) resulted in increased Schwann cell number, ki67+ staining, and gene expression of trophic factors and the critical NMJ organizing protein Agrin. Furthermore, differentiated C2C12 myotubes treated with conditioned media from PQ treated Schwann cell cultures showed increased number of acetylcholine receptor (AChR) plaques. The goal of the current study was to characterize NMJs in young Sod1 -/- mice (2-months) to determine the early effects of elevated oxidative stress on NMJ structure in vivo with a specific focus on tSCs. We hypothesized that loss of Sod1 would lead to aberrant tSC and NMJ structure associated with decreased muscle function. We assessed maximum isometric force, NMJ morphology, and number of Schwann cells in gastrocnemius muscles of WT (n = 3) and Sod1 -/- (n = 3) mice. In Sod1 -/- mice, muscle force was reduced by 26% ( p = 2e-4) with nerve stimulation compared to direct muscle stimulation, and overlap between motor nerve terminals and AChRs was reduced by nearly 60% compared to WT controls. Post-synaptic AChR area was increased by 37% in Sod1 -/- mice, and tSC area and numbers per NMJ were increased by 60% and 155%, respectively in Sod1 -/- mice. Finally, Schwann cells proximal to NMJs showed increased Ki67+ labeling in Sod1 -/- mice compared to WT mice. This analysis demonstrates that early changes in both pre- and post-synaptic NMJ components and reduced neurotransmission due to loss of Sod1 are associated with marked increases in tSC proliferation. Our data implicate a protective role of muscle-resident Schwann cells in preserving NMJ integrity in response to alterations in redox homeostasis that may be mediated in part through activation and proliferation of these cells. These findings indicate that further investigation of the dynamics between Schwann cells and NMJ function is important to increase understanding of neuromuscular degenerativeconditions that involve altered redox homeostasis such as sarcopenia. Supported by the University of Michigan Medical School Office of Research, the American Physiological Society, and NIH AR069620. This is the full abstract presented at the American Physiology Summit 2023 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.

Mannan oligosaccharides alleviate oxidative injury in the head kidney and spleen in grass carp (Ctenopharyngodon idella) via the Nrf2 signaling pathway after Aeromonas hydrophila infection

BackgroundMannan oligosaccharides (MOS) are recommended as aquaculture additives owing to their excellent antioxidant properties. In the present study, we examined the effects of dietary MOS on the head kidney and spleen of grass carp (Ctenopharyngodon idella) with Aeromonas hydrophila infection.MethodsA total of 540 grass carp were used for the study. They were administered six gradient dosages of the MOS diet (0, 200, 400, 600, 800, and 1,000 mg/kg) for 60 d. Subsequently, we performed a 14-day Aeromonas hydrophila challenge experiment. The antioxidant capacity of the head kidney and spleen were examined using spectrophotometry, DNA fragmentation, qRT-PCR, and Western blotting.ResultsAfter infection with Aeromonas hydrophila, 400–600 mg/kg MOS supplementation decreased the levels of reactive oxygen species, protein carbonyl, and malonaldehyde and increased the levels of anti-superoxide anion, anti-hydroxyl radical, and glutathione in the head kidney and spleen of grass carp. The activities of copper-zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione S-transferase, glutathione reductase, and glutathione peroxidase were also enhanced by supplementation with 400–600 mg/kg MOS. Furthermore, the expression of most antioxidant enzymes and their corresponding genes increased significantly with supplementation of 200–800 mg/kg MOS. mRNA and protein levels of nuclear factor erythroid 2-related factor 2 also increased following supplementation with 400–600 mg/kg MOS. In addition, supplementation with 400–600 mg/kg MOS reduced excessive apoptosis by inhibiting the death receptor pathway and mitochondrial pathway processes.ConclusionsBased on the quadratic regression analysis of the above biomarkers (reactive oxygen species, malondialdehyde, and protein carbonyl) of oxidative damage in the head kidney and spleen of on-growing grass carp, the recommended MOS supplementation is 575.21, 557.58, 531.86, 597.35, 570.16, and 553.80 mg/kg, respectively. Collectively, MOS supplementation could alleviate oxidative injury in the head kidney and spleen of grass carp infected with Aeromonas hydrophila.