Antioxidants & Redox Signaling

Cytosolic thioredoxin 1 (Trx1, TXN, TRX) is a central player in redox control. Thioredoxin interacting protein (TXNIP), an α-arrestin regulating glucose metabolism and inflammation, is widely regarded to inhibit TRX activity. However, the interactions between the two proteins across various cellular contexts remain poorly understood; in addition, only a limited number of studies have yet been conducted in human primary cells. We thus aimed here to investigate the functional relationship between TRX and TXNIP in human primary cells. We studied whether TXNIP inhibits TRX cellular activity in these primary cells and how this interaction influences cellular redox biology or glucose metabolism.

In primary cells, TXNIP deficiency did not increase cellular TRX activity. Instead, TXNIP deficiency elevated PGC-1α and PDK4 transcripts, increased PDHA1 Ser293 phosphorylation, and raised basal GLUT4, consistent with enhanced glucose uptake and restrained flux through the pyruvate dehydrogenase complex. Conversely, lowering TRX expression levels triggered higher TXNIP levels. This in turn correlated with suppressed transcripts for PGC-1α and PDK4, a lower extent of PDHA1 phosphorylation at Ser293, and decreased glucose uptake.

Our findings suggest that TXNIP, against common belief, may not necessarily be an endogenous inhibitor of TRX but, rather, that TRX can be an inhibitor of TXNIP.

This study reveals that the key intracellular redox protein TRX inversely regulates TXNIP, suggesting that modulation of the TRX system may provide a previously unrecognized therapeutic avenue for modulation of glucose metabolism. Antioxid. Redox Signal. 44, 643–660.

Parkinson’s disease (PD) is a common neurodegenerative disease characterized by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc) and the aggregation of alpha-synuclein (α-syn) in Lewy bodies. Emerging studies find that disruption of the Golgi structure and Golgi stress are involved in PD. Thioredoxin-1 (Trx-1) is a redox regulatory protein that protects DA neurons from methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) damage. However, whether Trx-1 can protect DA neurons against MPTP-induced Golgi stress is still unknown.

We first made sure that MPTP led to the loss of DA neurons in the SNpc and motor impairment in mice, which was reversed in Trx-1 overexpression mice. Trx-1 overexpression suppressed Golgi apparatus fragmentation, α-syn aggregation, oxidative stress, and protein kinase C zeta expression increased by MPTP. Trx-1 overexpression restored the colocalization of Trx-1 and tyrosine hydroxylase with Golgi matrix protein 130 (GM130), decreased by MPTP. Moreover, Trx-1 overexpression suppressed the increased co-localization of Leucine-rich repeat kinase 2 and Ras-associated binding protein 29 with vacuolar protein sorting-associated protein 52 induced by MPTP. Trx-1 overexpression suppressed the expression changes of ADP-ribosylation factor 4 and heat shock protein 47, and their colocalization with GM130 induced by MPTP.

Our study reveals a novel mechanism, whereby Trx-1 inhibits Golgi stress in DA neuron induced by MPTP.

These results suggest that Trx-1 may regulate the development of PD through inhibiting Golgi stress and is a potential new molecular target and therapeutic strategy for Golgi stress involved in PD. Antioxid. Redox Signal. 44, 661–675.

Ferroptosis, an iron- and lipid peroxidation-dependent mode of programmed cell death, is presently realized as a converging mediator that bridges redox imbalance and metabolic dysfunction. Differing from apoptosis and necroptosis, ferroptosis involves iron homeostasis, glutathione depletion, and redox lipid damage. Thus, it becomes the intersection of metabolic reprogramming and redox signaling. Ferroptosis is a double-edged metabolic vulnerability and adaptive resistance pathway in malignancy.

Oncogenic signaling cascades such as PI3K/Akt/mTOR and AMPK restructure glucose and lipid metabolism to regulate ferroptotic sensitivity, whereas cancer cells destabilize antioxidant defense pathways such as Xc⁻-GSH-GPX4 and FSP1-CoQ10-NAD(P)H pathways to evade ferroptotic cell death. Pharmacological inducers erastin, RSL3, and sorafenib reverse oxidative imbalance, enhance antitumor effect, and immune modulation in the tumor microenvironment. In diabetic mellitus complications, ferroptosis is responsible for β-cell deterioration, insulin resistance, and vascular injury. Hyperglycemia-induced oxidative stress and dysregulated GPX4 facilitate lipid peroxidation and ferroptotic cell death in pancreatic β-cells, while iron overload and mitochondrial dysfunctions facilitate ferroptotic injury in diabetic cardiomyopathy, nephropathy, retinopathy, and foot ulcer. These observations position ferroptosis as a crucial metabolically reorganized hub of organ damage.

Despite rapid advancements, foundational challenges persist, including the identification of ferroptosis-specific biomarkers, tissue-specific thresholds, and mechanisms for neutralizing off-target toxicity.

Recently developed technologies such as CRISPR-based functional genomics, metabolomics, and AI-powered modeling represent new-age tools in defining ferroptosis networks and precision therapeutics design. Integration of the regulation of normal physiological ferroptosis into cancer and diabetes therapy has the potential to redefine redox-targeted therapy and metabolic medicine. Antioxid. Redox Signal. 44, 676–711.

To evaluate the impact of the composite dietary antioxidant index (CDAI) on the progression from hypertension (HT) to cardiovascular diseases (CVDs) and subsequent death.

This prospective study included 100,193 participants (median age 55) initially free of HT and CVDs from the UK Biobank. The CDAI was calculated from the intake of six dietary antioxidants, including manganese, selenium, zinc, and vitamins A, C, and E. Multivariable Cox regression analysis assessed the relationship between CDAI and the risks of HT, CVDs, and all-cause mortality. Multistate models were used to examine the impact of CDAI levels on CVD progression trajectories.

During a median follow-up of 14.10 years, 11,998 participants developed HT, 3656 developed CVDs, and 4169 died. CDAI was inversely associated with the risk of adverse outcomes, including HT, CVDs, and death. Compared with the lowest CDAI quartile, the adjusted hazard ratios (HRs; confidence intervals [CIs]) for the highest quartile in transitions from baseline to HT, to CVDs, and to death were 0.913 (0.868–0.960), 0.890 (0.799–0.992), and 0.850 (0.767–0.942), respectively. An association between the highest quartile CDAI and reduced risk was also observed in transitions from HT to CVDs (HR: 0.698; 95% CI: 0.558–0.872) and from HT to death (HR: 0.803; 95% CI: 0.648–0.995). Mediation analysis indicates that the reduction in CVD and mortality risk associated with CDAI primarily depends on its direct effect rather than its indirect effect through HT.

The CDAI influences the progression of CVD trajectories, underscoring the need for dietary adjustments to elevate CDAI levels in CVD health management. Antioxid. Redox Signal. 44, 712–725.

Vascular restenosis is a common complication following vascular interventions, driven by abnormal proliferation and phenotypic switching of vascular smooth muscle cells (VSMCs). Ferroptosis, an iron-dependent regulated cell death, has been implicated in VSMC dysfunction and vascular remodeling. However, the epitranscriptomic regulation of ferroptosis in VSMCs remains unclear.

This study investigates the role of Wilms tumor suppressor gene WT1-associated protein (WTAP), a key N6-methyladenosine (m6A) RNA methylation regulator, in controlling ferroptosis of VSMCs during vascular restenosis.

A balloon injury rat model and platelet-derived growth factor-BB-stimulated VSMCs were used to mimic vascular restenosis. WTAP expression and global m6A levels were assessed. Functional assays evaluated the effects of WTAP overexpression on ferroptosis markers, reactive oxygen species (ROS), lipid peroxidation, and VSMC proliferation. Mechanistic studies explored WTAP-mediated m6A modification of the long non-coding RNA growth arrest specific 5 (GAS5), its interaction with enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), and downstream regulation of interferon regulatory factor 4 (IRF4) and ferritin heavy chain 1 (FTH1).

WTAP expression and global m6A levels were significantly reduced in restenotic tissues and cells. WTAP overexpression restored m6A modification on GAS5, enhancing its stability via YTH domain family member 1. GAS5 inhibited EZH2-mediated H3K27me3 repression of IRF4, which transcriptionally activated FTH1, suppressing ferroptosis. WTAP overexpression decreased ROS, lipid peroxidation, and VSMC proliferation, while knockdown of GAS5 or IRF4 partially reversed these effects.

Our study is the first to identify that the WTAP/GAS5/IRF4 axis suppresses PDGF-BB-induced cell proliferation by inhibiting ferroptosis in VSMCs, and alleviates vascular restenosis caused by balloon injury.

WTAP epitranscriptomically regulates VSMC ferroptosis via the GAS5/EZH2/IRF4/FTH1 axis, revealing a novel mechanism in vascular restenosis pathogenesis and a potential therapeutic target. Antioxid. Redox Signal. 44, 726–747.

Obstetric antiphospholipid syndrome (OAPS), a representative autoimmune disorder driven by antiphospholipid antibodies (aPLs), afflicts 30% of patients with refractory to conventional antithrombotic treatment. Hydroxychloroquine (HCQ) offers adjunctive potential, yet its mechanistic action and critical treatment timing remain undefined. This study establishes the preventive efficacy of preconception HCQ initiation (HCQ-pre) and deciphers its fundamental rescue pathways in OAPS.

Clinical data suggested a potential advantage of HCQ-pre compared to post-conception administration (HCQ-post) in optimizing pregnancy outcomes for patients with OAPS. Modeling the pathology of OAPS using human trophoblast organoids revealed that HCQ-pre effectively reverses aPLs-mediated trophoblast dysfunction: increasing cytotrophoblast proliferation (Ki67⁺/TP63⁺) by 20% and restoring their differentiation into extravillous trophoblast (HLA-G⁺) to 93% of control levels, while HCQ-post shows markedly limited efficacy. Mechanistically, HCQ-pre preemptively corrected aPLs-induced redox imbalance by rescuing hypoxia-inducible factor 1-alpha-mediated hypoxia and replenishing antioxidant mediators (NRF2/SOD2/GPX4) via Hippo/YAP and Wnt/β-catenin signaling. Murine OAPS models established that HCQ-pre restores placental perfusion (90% of control levels) by enhancing spiral artery remodeling—with diminished efficacy observed at post-conception administration—thereby attenuating hypoperfusion-induced hypoxic damage and improving pregnancy outcomes.

We redefine HCQ as a proactive placental resetter that neutralizes oxidative stress barriers preconception, thereby liberating trophoblast differentiation capacity. This work positions HCQ-pre as the critical intervention phase—a paradigm shift from reactive adjunct to preemptive root-cause interception, providing the mechanistic foundation for optimizing OAPS management through timely individualized prophylaxis. Antioxid. Redox Signal. 44, 748–769.

To determine whether dysregulated copper metabolism and cuproptosis contribute to acute lung injury (ALI), and to evaluate whether targeting copper homeostasis mitigates lung inflammation and injury.

Integrative analysis of RNA-seq data from patients with severe community-acquired pneumonia revealed increased enrichment of copper metabolism-related gene sets and differential expression of cuproptosis-related genes. Notably, immune deconvolution of patient RNA-seq data demonstrated prominent macrophage enrichment, suggesting that macrophages represent a major cell group in which dysregulated copper metabolism may occur during ALI. In a lipopolysaccharide (LPS)-induced mouse ALI model, lung copper levels were elevated, accompanied by molecular features of cuproptosis, including increased DLAT oligomerization and destabilization of Fe–S cluster proteins. Pretreatment with the copper chelator tetrathiomolybdate alleviated lung injury and inflammatory response, while suppressing cuproptosis-related molecular features in vivo. In alveolar macrophages, LPS challenge increased intracellular Cu⁺ concentration and promoted DLAT oligomerization, and impaired Fe–S protein stability. Mechanistically, both copper chelation and knockdown of upstream cuproptosis regulator reduced DLAT oligomerization, restored Fe–S proteins, alleviated mitochondrial dysfunction, and decreased CD86⁺ macrophage polarization. Importantly, altered expression of copper transporters was observed, suggesting a remodeling of copper metabolic homeostasis during ALI.

This study identifies cuproptosis as a previously unrecognized driver of ALI, mechanistically linking copper dysregulation to mitochondrial damage and inflammatory activation of alveolar macrophages, and demonstrates the therapeutic benefit of copper chelation or cuproptosis suppression. Antioxid. Redox Signal. 44, 770–791.