-
Biomedicine & Pharmacotherapy =... Dec 2023Diabetic retinopathy (DR) is currently recognized as the leading cause of end-stage eye disease. Pipecolic acid, a metabolite, has a significant regulatory effect on...
Diabetic retinopathy (DR) is currently recognized as the leading cause of end-stage eye disease. Pipecolic acid, a metabolite, has a significant regulatory effect on several pathological processes. However, the exact mechanism by which it causes damage in diabetic retinopathy is unknown. Between September 2021 and December 2022, 40 patients were retrospectively examined and divided into two groups: the healthy group (n = 20) and the DR group (n = 20). Metabolomic analysis found that pipecolic acid plays an important role in this process. Streptozotocin-induced diabetic mice and high-glucose cultured human retinal capillary endothelial cells (HRCECs) were then treated with pipecolic acid. Several oxidative stress measurements and RNA sequencing of retinal cells were tested. A gene interaction study was conducted using bioinformatics. Comparison of serological metabolites between healthy volunteers and DR patients showed that pipecolic acid was significantly lower in DR patients, and there was a negative correlation between the level of pipecolic acid with blood glucose and glycated hemoglobin. Yes-associated protein (YAP) mRNA, Malondialdehyde (MDA), and reactive oxygen species (ROS) levels were significantly higher in diabetic mice, but glutathione peroxidase (GSH-Px) levels were significantly lower. Pipecolic acid significantly alleviated oxidative stress and YAP expression. The number of vascular tubes was significantly higher in the DR group, and pipecolic acid treatment significantly reduced tube formation. RNA-Sequencing analysis revealed that YAP and glutathione-dependent lipid hydroperoxidase glutathione peroxidase 4 (GPX4) expression was reduced, and functional enrichment analysis revealed that ferroptosis and Hippo signaling pathways play an important role in this process. Additionally, pipecolic acid's ability to improve DR is diminished after YAP and GPX4 ablation. This study found that pipecolic acid, as a metabolite, may impede the progression of DR by inhibiting the YAP-GPX4 signaling pathway.
Topics: Humans; Mice; Animals; Phospholipid Hydroperoxide Glutathione Peroxidase; Ferroptosis; Diabetic Retinopathy; Diabetes Mellitus, Experimental; Endothelial Cells; Retrospective Studies; Reactive Oxygen Species; Signal Transduction
PubMed: 37984309
DOI: 10.1016/j.biopha.2023.115895 -
Frontiers in Endocrinology 2023Autoimmune thyroid disease is a prevalent condition affecting women of reproductive age, leading to thyroid dysfunction and impacting pregnancy outcomes. While the...
BACKGROUND
Autoimmune thyroid disease is a prevalent condition affecting women of reproductive age, leading to thyroid dysfunction and impacting pregnancy outcomes. While the critical role of thyroid hormone in pregnancy outcomes is well-established, the potential association between positive anti-thyroid peroxidase antibodies (TPOAb) and adverse pregnancy outcomes in pregnant women with normal thyroid function remains unclear.
OBJECTIVE
This study aims to investigate the relationship between maternal TPOAb positivity and adverse pregnancy outcomes with normal thyroid function.
METHODS
We collected baseline information from pregnant women who visited our hospital between February 2009 and June 2012. Blood samples were taken to measure thyroid stimulating hormone (TSH), free thyroxine (FT4), TPOAb, and anti-thyroglobulin antibodies (TGAb). The incidence of adverse pregnancy outcomes was compared between TPOAb-positive and TPOAb-negative groups among participants with normal thyroid function.
RESULTS
A total of 7,046 pregnant women with normal thyroid function were included, comprising 6,700 with negative TPOAb and 346 with positive TPOAb. The TPOAb-positive group exhibited a higher age (26.0 vs. 27.0 years, = 0.02) and greater serum TSH levels (1.72 vs. 1.94 mIU/L, = 0.029), while the gestational week of blood collection was lower (31.9 vs. 26.5 weeks, = 0.001). Univariate analysis revealed a higher incidence of low birth weight (LBW) in offspring of TPOAb-positive women compared to the TPOAb-negative group (3.5% vs. 1.9%, = 0.035). After adjusting for confounding factors such as age, gestational week of blood collection, menstrual history, education level, gestational diabetes, gestational hypertension, TGAb, TSH, and FT4, TPOAb positivity emerged as an independent risk factor for LBW infants (OR: 2.317, 95% CI: 1.057-5.076, = 0.036), while other adverse pregnancy outcomes did not show a significant correlation with TPOAb positivity.
CONCLUSION
Our findings suggest that TPOAb-positive pregnant women with normal thyroid function are more likely to deliver LBW infants. Regular monitoring of TPOAb-positive pregnancies and timely interventions throughout all stages of pregnancy are crucial.
Topics: Infant, Newborn; Female; Pregnancy; Humans; Infant; Iodide Peroxidase; Thyroxine; Incidence; Thyroid Hormones; Thyrotropin; Infant, Low Birth Weight
PubMed: 38047117
DOI: 10.3389/fendo.2023.1285504 -
Journal of Molecular Biology Jul 2023Macromolecular interactions regulate all aspects of biology. The identification of interacting partners and complexes is important for understanding cellular processes,...
Macromolecular interactions regulate all aspects of biology. The identification of interacting partners and complexes is important for understanding cellular processes, host-pathogen conflicts, and organismal development. Multiple methods exist to label and enrich interacting proteins in living cells. Notably, the soybean ascorbate peroxidase, APEX2, rapidly biotinylates adjacent biomolecules in the presence of biotin-phenol and hydrogen peroxide. However, during initial experiments with this system, we found that APEX2 exhibits a cytoplasmic-biased localization and is sensitive to the nuclear export inhibitor leptomycin B (LMB). This led us to identify a putative nuclear export signal (NES) at the carboxy-terminus of APEX2 (NES), structurally adjacent to the conserved heme binding site. This putative NES is functional as evidenced by cytoplasmic localization and LMB sensitivity of a mCherry-NES chimeric construct. Single amino acid substitutions of multiple hydrophobic residues within NES eliminate cytoplasm-biased localization of both mCherry-NES as well as full-length APEX2. However, all but one of these NES substitutions also compromises peroxide-dependent labeling. This unique separation-of-function mutant, APEX2-L242A, is termed APEX3. Localization and functionality of APEX3 are confirmed by fusion to the nucleocytoplasmic shuttling transcriptional factor, RELA. APEX3 is therefore an optimized tool for unbiased proximity labeling of cellular proteins and interacting factors..
Topics: Active Transport, Cell Nucleus; Cell Nucleus; Cytoplasm; Ascorbate Peroxidases; Nuclear Export Signals; Staining and Labeling
PubMed: 37182813
DOI: 10.1016/j.jmb.2023.168145 -
Redox Biology Aug 2023Our previous studies support a key role for mitochondrial lipid hydroperoxides as important contributors to denervation-related muscle atrophy, including muscle atrophy...
Our previous studies support a key role for mitochondrial lipid hydroperoxides as important contributors to denervation-related muscle atrophy, including muscle atrophy associated with aging. Phospholipid hydroperoxide glutathione peroxidase 4 (GPX4) is an essential antioxidant enzyme that directly reduces phospholipid hydroperoxides and we previously reported that denervation-induced muscle atrophy is blunted in a mouse model of GPX4 overexpression. Therefore, the goal of the present study was to determine whether GPX4 overexpression can reduce the age-related increase in mitochondrial hydroperoxides in skeletal muscle and ameliorate age-related muscle atrophy and weakness (sarcopenia). Male C57Bl6 WT and GPX4 transgenic (GPX4Tg) mice were studied at 3 to 5 and 23-29 months of age. Basal mitochondrial peroxide generation was reduced by 34% in muscle fibers from aged GPX4Tg compared to old WT mice. GPX4 overexpression also reduced levels of lipid peroxidation products: 4-HNE, MDA, and LOOHs by 38%, 32%, and 84% respectively in aged GPX4Tg mice compared to aged WT mice. Muscle mass was preserved in old GPX4 Tg mice by 11% and specific force generation was 21% higher in old GPX4Tg versus age matched male WT mice. Oxylipins from lipoxygenases (LOX) and cyclooxygenase (COX), as well as less abundant non-enzymatically generated isomers, were significantly reduced by GPX4 overexpression. The expression of cPLA2, 12/15-LOX and COX-2 were 1.9-, 10.5- and 3.4-fold greater in old versus young WT muscle respectively, and 12/15-LOX and COX-2 levels were reduced by 37% and 35%, respectively in muscle from old GPX4Tg mice. Our study suggests that lipid peroxidation products may play an important role in the development of sarcopenia, and their detoxification might be an effective intervention in preventing muscle atrophy.
Topics: Animals; Male; Mice; Cyclooxygenase 2; Glutathione Peroxidase; Muscle, Skeletal; Muscular Atrophy; Oxylipins; Phospholipid Hydroperoxide Glutathione Peroxidase; Sarcopenia
PubMed: 37279604
DOI: 10.1016/j.redox.2023.102761 -
Journal of Nanobiotechnology May 2024Various clinical symptoms of digestive system, such as infectious, inflammatory, and malignant disorders, have a profound impact on the quality of life and overall... (Review)
Review
Various clinical symptoms of digestive system, such as infectious, inflammatory, and malignant disorders, have a profound impact on the quality of life and overall health of patients. Therefore, the chase for more potent medicines is both highly significant and urgent. Nanozymes, a novel class of nanomaterials, amalgamate the biological properties of nanomaterials with the catalytic activity of enzymes, and have been engineered for various biomedical applications, including complex gastrointestinal diseases (GI). Particularly, because of their distinctive metal coordination structure and ability to maximize atom use efficiency, single-atom nanozymes (SAzymes) with atomically scattered metal centers are becoming a more viable substitute for natural enzymes. Traditional nanozyme design strategies are no longer able to meet the current requirements for efficient and diverse SAzymes design due to the diversification and complexity of preparation processes. As a result, this review emphasizes the design concept and the synthesis strategy of SAzymes, and corresponding bioenzyme-like activities, such as superoxide dismutase (SOD), peroxidase (POD), oxidase (OXD), catalase (CAT), and glutathione peroxidase (GPx). Then the various application of SAzymes in GI illnesses are summarized, which should encourage further research into nanozymes to achieve better application characteristics.
Topics: Humans; Gastrointestinal Diseases; Nanostructures; Animals; Enzymes; Superoxide Dismutase; Catalase; Catalysis; Glutathione Peroxidase
PubMed: 38796465
DOI: 10.1186/s12951-024-02569-3 -
Biochemical Society Transactions Oct 2023Peroxidasin is a heme-containing peroxidase enzyme that plays a vital role in the cross-linking of collagen IV molecules in basement membranes. Collagen IV cross-links... (Review)
Review
Peroxidasin is a heme-containing peroxidase enzyme that plays a vital role in the cross-linking of collagen IV molecules in basement membranes. Collagen IV cross-links are essential for providing structure and mechanical stability throughout tissue development, homeostasis, and wound healing. During cancer progression, the basement membrane is degraded, and proteins typically found in the basement membrane, including peroxidasin and collagen IV, can be found spread throughout the tumour microenvironment where they interact with cancer cells and alter cell behaviour. Whilst peroxidasin is reported to be up-regulated in a number of different cancers, the role that it plays in disease progression and metastasis has only recently begun to be studied. This review highlights the current literature exploring the known roles of peroxidasin in normal tissues and cancer progression, regulators of peroxidasin expression, and the reported relationships between peroxidasin expression and patient outcome in cancer.
Topics: Humans; Peroxidase; Extracellular Matrix Proteins; Collagen Type IV; Basement Membrane; Neoplasms; Tumor Microenvironment; Peroxidasin
PubMed: 37801286
DOI: 10.1042/BST20230018 -
The Journal of Physiology Dec 2023Our laboratory previously showed lipid hydroperoxides and oxylipin levels are elevated in response to loss of skeletal muscle innervation and are associated with muscle...
Our laboratory previously showed lipid hydroperoxides and oxylipin levels are elevated in response to loss of skeletal muscle innervation and are associated with muscle pathologies. To elucidate the pathological impact of lipid hydroperoxides, we overexpressed glutathione peroxidase 4 (GPx4), an enzyme that targets reduction of lipid hydroperoxides in membranes, in adult CuZn superoxide dismutase knockout (Sod1KO) mice that show accelerated muscle atrophy associated with loss of innervation. The gastrocnemius muscle from Sod1KO mice shows reduced mitochondrial respiration and elevated oxidative stress (F -isoprostanes and hydroperoxides) compared to wild-type (WT) mice. Overexpression of GPx4 improved mitochondrial respiration and reduced hydroperoxide generation in Sod1KO mice, but did not attenuate the muscle loss that occurs in Sod1KO mice. In contrast, contractile force generation is reduced in EDL muscle in Sod1KO mice relative to WT mice, and overexpression of GPx4 restored force generation to WT levels in Sod1KO mice. GPx4 overexpression also prevented loss of muscle contractility at the single fibre level in fast-twitch fibres from Sod1KO mice. Muscle fibres from Sod1KO mice were less sensitive to both depolarization and calcium at the single fibre level and exhibited a reduced activation by S-glutathionylation. GPx4 overexpression in Sod1KO mice rescued the deficits in both membrane excitability and calcium sensitivity of fast-twitch muscle fibres. Overexpression of GPx4 also restored the sarco/endoplasmic reticulum Ca -ATPase activity in Sod1KO gastrocnemius muscles. These data suggest that GPx4 plays an important role in preserving excitation-contraction coupling function and Ca homeostasis, and in maintaining muscle and mitochondrial function in oxidative stress-induced sarcopenia. KEY POINTS: Knockout of CuZn superoxide dismutase (Sod1KO) induces elevated oxidative stress with accelerated muscle atrophy and weakness. Glutathione peroxidase 4 (GPx4) plays a fundamental role in the reduction of lipid hydroperoxides in membranes, and overexpression of GPx4 improves mitochondrial respiration and reduces hydroperoxide generation in Sod1KO mice. Muscle contractile function deficits in Sod1KO mice are alleviated by the overexpression of GPx4. GPx4 overexpression in Sod1KO mice rescues the impaired muscle membrane excitability of fast-twitch muscle fibres and improves their calcium sensitivity. Sarco/endoplasmic reticulum Ca -ATPase activity in Sod1KO muscles is decreased, and it is restored by the overexpression of GPx4. Our results confirm that GPx4 plays an important role in preserving excitation-contraction coupling function and Ca homeostasis, and maintaining muscle and mitochondrial function in oxidative stress-induced sarcopenia.
Topics: Animals; Mice; Adenosine Triphosphatases; Calcium; Glutathione; Glutathione Peroxidase; Hydrogen Peroxide; Lipids; Mice, Knockout; Muscle, Skeletal; Phenotype; Phospholipid Hydroperoxide Glutathione Peroxidase; Sarcopenia; Superoxide Dismutase; Superoxide Dismutase-1
PubMed: 37878529
DOI: 10.1113/JP285259 -
International Immunopharmacology May 2024Chondrocyte ferroptosis plays a critical role in the pathogenesis of osteoarthritis (OA), regulated by the SLC7A11/GPX4 signaling pathway. Icariin (ICA), a flavonoid...
BACKGROUND
Chondrocyte ferroptosis plays a critical role in the pathogenesis of osteoarthritis (OA), regulated by the SLC7A11/GPX4 signaling pathway. Icariin (ICA), a flavonoid glycoside, exhibits strong anti-inflammatory and antioxidant activities. This study investigated whether ICA could modulate the SLC7A11/GPX4 signaling to inhibit chondrocyte ferroptosis and alleviate OA.
PURPOSE
The objective was to explore the impact of ICA on chondrocyte ferroptosis in OA and its modulation of the SLC7A11/GPX4 signaling pathway.
METHODS
The anti-ferroptosis effects of ICA were evaluated in an interleukin-1β (IL-1β)-treated SW1353 cell model, using Ferrostatin-1 (Fer-1) and Erastin (Era) as ferroptosis inhibitor and inducer, respectively, along with GPX4 knockdown via lentivirus-based shRNA. Additionally, the therapeutic efficacy of ICA on OA-related articular cartilage damage was assessed in rats through histopathology and immunohistochemistry (IHC).
RESULTS
IL-1β treatment upregulated the expression of OA-associated matrix metalloproteinases (MMP3 and MMP1), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-5), and increased intracellular ROS, lipid ROS, and MDA levels while downregulating collagen II and SOX9 expression in SW1353 cells. ICA treatment countered the IL-1β-induced upregulation of MMPs and ADAMTS-5, restored collagen II and SOX9 expression, and reduced intracellular ROS, lipid ROS, and MDA levels. Furthermore, IL-1β upregulated P53 but downregulated SLC7A11 and GPX4 expression in SW1353 cells, effects that were mitigated by ICA or Fer-1 treatment. Significantly, ICA also alleviated Era-induced ferroptosis, whereas it had no effect on GPX4-silenced SW1353 cells. In vivo, ICA treatment reduced articular cartilage damage in OA rats by partially restoring collagen II and GPX4 expression, inhibiting cartilage extracellular matrix (ECM) degradation and chondrocyte ferroptosis.
CONCLUSION
ICA treatment mitigated chondrocyte ferroptosis and articular cartilage damage by enhancing the SLC7A11/GPX4 signaling, suggesting its potential as a therapeutic agent for OA interventions.
Topics: Animals; Humans; Male; Rats; Amino Acid Transport System y+; Anti-Inflammatory Agents; Cartilage, Articular; Cell Line; Chondrocytes; Ferroptosis; Flavonoids; Interleukin-1beta; Osteoarthritis; Phospholipid Hydroperoxide Glutathione Peroxidase; Rats, Sprague-Dawley; Signal Transduction
PubMed: 38636375
DOI: 10.1016/j.intimp.2024.112010 -
Ecotoxicology and Environmental Safety Aug 2023Fluoranthene (Flu) uptake by plants is affected by plant growth and environmental concentration. Although plant growth processes, including substance synthesis and...
Fluoranthene (Flu) uptake by plants is affected by plant growth and environmental concentration. Although plant growth processes, including substance synthesis and antioxidant enzyme activities, have been reported to regulate Flu uptake, their contributions have been poorly evaluated. Moreover, the effect of Flu concentration is little known. Here, low concentrations (0, 1, 5, and 10 mg/L) and high concentrations (20, 30, and 40 mg/L) of Flu were set to compare the changes in Flu uptake by ryegrass (Lolium multiflorum Lam.). Indices of plant growth (biomass, root length, root area, root tip number, and photosynthesis and transpiration rates), substance synthesis (indole acetic acid [IAA] content), and antioxidant enzyme activities (superoxide dismutase [SOD], peroxidase [POD], and catalase [CAT]) were recorded to unravel the mechanism of Flu uptake. Findings suggested that the Langmuir model fitted Flu uptake by ryegrass well. Flu absorption capacity in the root was stronger than that that in the leaf. Flu bioconcentration and translocation factors increased then reduced with the increase in Flu concentration and reached the maximum value under 5 mg/L Flu treatment. Plant growth and IAA content had the same pattern as before bioconcentration factor (BCF). SOD and POD activities increased then decreased with Flu concentration and reached their highest levels under 30 and 20 mg/L Flu treatments, respectively, whereas CAT activity decreased continuously and reached its lowest level under 40 mg/L Flu treatment. Variance partitioning analysis indicated that IAA content had the greatest significant effect on Flu uptake under low-concentration Flu treatments, whereas antioxidant enzyme activities had the greatest significant effect on Flu uptake under high-concentration Flu treatments. Revealing the concentration-dependent mechanisms of Flu uptake could provide a basis for regulating pollutant accumulation in plants.
Topics: Antioxidants; Lolium; Peroxidase; Superoxide Dismutase
PubMed: 37285675
DOI: 10.1016/j.ecoenv.2023.115088 -
Annals of the Rheumatic Diseases Mar 2024Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides (AAV) are life-threatening systemic autoimmune diseases manifesting in the kidneys as necrotizing...
OBJECTIVES
Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides (AAV) are life-threatening systemic autoimmune diseases manifesting in the kidneys as necrotizing crescentic glomerulonephritis (NCGN). ANCA antigens are myeloperoxidase (MPO) or proteinase 3. Current treatments include steroids, cytotoxic drugs and B cell-depleting antibodies. The use of chimeric antigen receptor (CAR) T cells in autoimmune diseases is a promising new therapeutic approach. We tested the hypothesis that CAR T cells targeting CD19 deplete B cells, including MPO-ANCA-producing B cells, thereby protecting from ANCA-induced NCGN.
METHODS
We tested this hypothesis in a preclinical MPO-AAV mouse model. NCGN was established by immunisation of MPO mice with murine MPO, followed by irradiation and transplantation with haematopoietic cells from wild-type mice alone or together with either CD19-targeting CAR T cells or control CAR T cells.
RESULTS
CD19 CAR T cells efficiently migrated to and persisted in bone marrow, spleen, peripheral blood and kidneys for up to 8 weeks. CD19 CAR T cells, but not control CAR T cells, depleted B cells and plasmablasts, enhanced the MPO-ANCA decline, and most importantly protected from NCGN.
CONCLUSION
Our proof-of-principle study may encourage further exploration of CAR T cells as a treatment for ANCA-vasculitis patients with the goal of drug-free remission.
Topics: Humans; Mice; Animals; Antibodies, Antineutrophil Cytoplasmic; Glomerulonephritis; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Acute Kidney Injury; T-Lymphocytes; Peroxidase
PubMed: 38182404
DOI: 10.1136/ard-2023-224875