ROS-Influenced Regulatory Cross-Talk With Wnt Signaling Pathway During Perinatal Development

Biodegradable, electroconductive self-healing hydrogel based on polydopamine-coated polyurethane nano-crosslinker for Parkinson's disease therapy

Parkinson's disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons, causing motor and neurological impairments. Current treatments offer only temporary symptom relief without halting progression. Herein, a fully biodegradable, electroconductive self-healing hydrogel (CPUD gel) is developed, incorporating electroconductive polydopamine-coated polyurethane nanoparticles (PUD) as crosslinker. The core-shell PUD nanoparticles have a highly uniform size of ∼36 nm with a polydopamine shell of ∼4.8 nm thick on polyurethane core, revealed by small angle X-ray scattering, and own a conductivity of ∼0.82 mS/cm. As nano-crosslinker, the PUD can react with chitosan to form the dynamic CPUD hydrogel with shear modulus (∼280 Pa) and conductivity (∼4.34 mS/cm), mimicking brain tissue properties. In vitro, CPUD gel supports neural stem cell (NSC) proliferation (∼565 %) and differentiation, with elevated neuronal marker expression at 14 days, while exhibiting strong antioxidative and anti-inflammatory effects, rescuing ∼88 % inflamed NSCs. A therapeutic strategy combining injectable CPUD gel with acupuncture in a PD rat model, aiming to activate the innate regenerative mechanisms of body through mobilized endogenous stem cells, is further established. Using this approach, this hydrogel significantly elevates serum TGF-β1/SDF-1 levels, promotes dopaminergic neuron regeneration (>80 %), modulates neuroinflammation through M1-to M2-microglia transition (∼12.6-fold M2/M1 ratio), and improves motor function (from 8 % to 37 % forelimb contacts) in 14 days. Particularly, the electrophysiological spike rate is recovered from 66 to 19 spikes/s, close to the healthy rate 15 spikes/s. The synergistic immunomodulation and neuroprotection highlight the potential of CPUD gel as an advanced therapeutic tool for PD.

Success and Controversy of Natural Products as Therapeutic Modulators of Wnt Signaling and Its Interplay with Oxidative Stress: Comprehensive Review Across Compound Classes and Experimental Systems

The highly conserved Wnt signaling pathway, a complex network critical for embryonic development and adult tissue homeostasis, regulates diverse cellular processes, ultimately influencing tissue organization and organogenesis; its dysregulation is implicated in numerous diseases, and it is known to be affected by oxidative pathways. This report reviews the recent literature on major classes of natural products with pronounced anti-oxidant properties, such as cardiac glycosides, steroid saponins, ecdysteroids, withanolides, cucurbitacins, triterpenes, flavonoids, and iridoids, that modulate its activity in various pathological conditions, summarizing and critically analyzing their effects on the Wnt pathway in various therapeutically relevant experimental models and highlighting the role of ROS-mediated crosstalk with Wnt signaling in these studies. Models reviewed include not only cancer but also stroke, ischemia, bone or kidney diseases, and regenerative medicine, such as re-epithelialization, cardiac maintenance, and hair loss. It highlights the paramount importance of modulating this signaling by natural products to define future research directions. We also discuss controversies identified in the mode of action of several compounds in different models and directions on how to further improve the quality and depth of such studies.

Molecular characterization, transcriptional profiling, and antioxidant activity assessment of nucleoredoxin (NXN) as a novel member of thioredoxin from red-lip mullet (Planiliza haematocheilus)

Nucleoredoxin (NXN) is a prominent oxidoreductase enzyme, classified under the thioredoxin family, and plays a pivotal role in regulating cellular redox homeostasis. Although the functional characterization of NXN has been extensively studied in mammals, its role in fish remains relatively unexplored. In this study, the NXN gene from Planiliza haematocheilus (PhNXN) was molecularly and functionally characterized using in silico tools, expression analyses, and in vitro assays. The predicted protein sequence of PhNXN contained 418 amino acids with an anticipated molecular mass of 47.53 kDa. It comprised a highly conserved 188CPPC191 catalytic motif in the central NXN domain and two thioredoxin-like domains enriched with conserved Cys residues. PhNXN protein was primarily localized in the cytoplasm and nucleus of the cells. The spatial and temporal expression analyses of PhNXN mRNA showed the highest expression level in the brain under normal physiological conditions, while a significant modulation was detected in the blood and head kidney following immunostimulation with polyinosinic: polycytidylic acid, lipopolysaccharides, and Lactococcus garvieae. Recombinant PhNXN protein exhibited DPPH radical scavenging, thiol-dependent disulfide reduction, and cupric ion reduction activities. Additionally, PhNXN overexpression significantly suppressed oxidative stress-induced cell death, heavy metal cation-induced reactive oxygen species production, and viral hemorrhagic septicemia virus-induced cellular apoptosis in fish cells. Furthermore, PhNXN overexpression in RAW 264.7 cells demonstrated notable nitric oxide scavenging activity, M2-type polarization, and anti-inflammatory effect. Collectively, the overall findings of the study highlight the antioxidant and immunological functions of PhNXN in red-lip mullet.

Phyto-mediated fabrication of silver nanoparticles from Scrophularia striata extract (AgNPs-SSE): a potential inducer of apoptosis in breast cancer cells

BACKGROUND

Breast carcinoma stands out as the most widespread invasive cancer and the top contributor to cancer-related mortality in women. Nanoparticles have emerged as promising tools in cancer detection, diagnosis, and prevention. In this study, the antitumor and apoptotic capability of silver nanoparticles synthesized through Scrophularia striata extract (AgNPs-SSE) was investigated toward breast cancer cells.

METHODS

The produced AgNPs-SSE were identified using scanning electron micrograph (SEM), energy-dispersive X-ray (EDAX) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). The cell-killing effects of AgNPs-SSE on MDA-MB231 mammary carcinoma cells were evaluated in vitro using the MTT assay over 24 h. Apoptosis induction was conducted by cell cycle analysis, annexin V-FITC/PI staining, reactive oxygen species (ROS) generation, and Hoechst staining. Additionally, the gene expression of βcatenin, GSK3β, and CyclinD1 was analyzed using quantitative real-time PCR (qRT-PCR).

RESULTS

Microscopic analysis confirmed the successful fabrication of globular AgNPs-SSE, with a mean particle dimension of 19 ± 10 nm. The MTT assay revealed that IC50 value of AgNPs-SSE was 48.5 µg/mL for mammary carcinoma cells and 114 µg/mL for normal cells. Annexin V-FITC/PI staining specified that 85.88% of cancer cells treated with AgNPs-SSE underwent either early or late apoptosis. Treatment with AgNPs-SSE also caused a considerable rise in the subG1 cell cycle population and ROS production. Furthermore, the upregulation of βcatenin and downregulation of CyclinD1 gene expression confirmed the apoptotic mechanism.

CONCLUSIONS

In conclusion, the findings suggest that phyto-synthesized AgNPs-SSE can restrain the expansion of breast carcinoma cells and provoke apoptosis through oxidative stress. These results highlight the potential of AgNPs-SSE as an antitumor agent against breast cancer.

FTO attenuates TNF-α-induced damage of proximal tubular epithelial cells in acute pancreatitis-induced acute kidney injury via targeting AQP3 in an N6-methyladenosine-dependent manner

BACKGROUND

Acute kidney injury (AKI) is a frequent complication of severe acute pancreatitis (SAP). Previous investigations have revealed the involvement of FTO alpha-ketoglutarate-dependent dioxygenase (FTO) and aquaporin 3 (AQP3) in AKI. Therefore, the aim of this study is to explore the association of FTO and AQP3 on proximal tubular epithelial cell damage in SAP-induced AKI.

METHODS

An in-vitro AKI model was established in human proximal tubular epithelial cells (PTECs) HK-2 via tumor necrosis factor-α (TNF-α) induction (20 ng/mL), after which FTO and AQP3 expression was manipulated and quantified by quantitative real-time PCR and Western blotting. The viability and apoptosis of PTECs under various conditions, and reactive oxygen species (ROS), superoxide dismutase (SOD), and malonaldehyde (MDA) levels within these cells were measured using commercial assay kits and flow cytometry. Methylated RNA immunoprecipitation and mRNA stability assays were performed to elucidate the mechanism of FTO-mediated N6-methyladenosine (m6A) modification. Western blotting was performed to quantify β-catenin protein levels in the PTECs.

RESULTS

FTO overexpression attenuated the TNF-α-induced decrease in viability and SOD levels, elevated apoptosis, increased levels of ROS and MDA, and diminished TNF-α-induced AQP3 expression and reduced β-catenin expression, but its silencing led to contradictory results. FTO negatively modulates AQP3 levels in RTECs in an m6A-depednent manner and compromises AQP3 stability. In addition, all FTO overexpression-induced effects in TNF-α-induced PTECs were neutralized following AQP3 upregulation.

CONCLUSION

FTO alleviates TNF-α-induced damage to PTECs in vitro by targeting AQP3 in an m6A-dependent manner.

tRNA modification enzyme-dependent redox homeostasis regulates synapse formation and memory

Post-transcriptional modification of RNA regulates gene expression at multiple levels. ALKBH8 is a tRNA-modifying enzyme that methylates wobble uridines in a subset of tRNAs to modulate translation. Through methylation of tRNA-selenocysteine, ALKBH8 promotes selenoprotein synthesis and regulates redox homeostasis. Pathogenic variants in ALKBH8 have been linked to intellectual disability disorders in the human population, but the role of ALKBH8 in the nervous system is unknown. Through in vivo studies in Drosophila, we show that ALKBH8 controls oxidative stress in the brain to restrain synaptic growth and support learning and memory. ALKBH8 null animals lack wobble uridine methylation and exhibit reduced protein synthesis in the nervous system, including a specific decrease in selenoprotein levels. Either loss of ALKBH8 or independent disruption of selenoprotein synthesis results in ectopic synapse formation. Genetic expression of antioxidant enzymes fully suppresses synaptic overgrowth in ALKBH8 null animals, confirming oxidative stress as the underlying cause of dysregulation. ALKBH8 null animals also exhibit associative memory impairments that are reversed by pharmacological antioxidant treatment. Together, these findings demonstrate the critical role of tRNA wobble uridine modification in redox homeostasis in the developing nervous system and reveal antioxidants as a potential therapy for ALKBH8-associated intellectual disability.

Gestational Fisetin Exerts Neuroprotection by Regulating Mitochondria-Directed Canonical Wnt Signaling, BBB Integrity, and Apoptosis in Prenatal VPA-Induced Rodent Model of Autism

Embryonic valproic acid (VPA) has been considered a potential risk factor for autism. Majority of studies indicated that targeting autism-associated alterations in VPA-induced autistic model could be promising in defining and designing therapeutics for autism. Numerous investigations in this field investigated the role of canonical Wnt signaling cascade in regulating the pathophysiology of autism. The impaired blood-brain barrier (BBB) permeability and mitochondrial dysfunction are some key implied features of the autistic brain. So, the current study was conducted to target canonical Wnt signaling pathway with a natural polyphenolic modulator cum antioxidant namely fisetin. A single dose of intraperitoneal VPA sodium salt (400 mg/kg) at gestational day 12.5 induced developmental delays, social behaviour impairments (tube dominance test), and anxiety-like behaviour (sucrose preference test) similar to autism. VPA induced mitochondrial damage and over-activated the canonical Wnt signaling which further increased the blood-brain barrier (BBB) disruption, apoptosis, and neuronal damage. Our findings revealed that oral administration of 10 mg/kg gestational fisetin (GD 13-till parturition) improved social and anxiety-like behaviour by modulating the ROS-regulated mitochondrial-canonical Wnt signaling. Moreover, fisetin controls BBB permeability, apoptosis, and neuronal damage in autism model proving its neuroprotective efficacy. Collectively, our findings revealed that fisetin-evoked modulation of the Wnt signaling cascade successfully relieved the associated symptoms of autism along with developmental delays in the model and indicates its potential as a bioceutical against autism.

Health risks of Bisphenol-A exposure: From Wnt signaling perspective

Human beings are routinely exposed to chronic and low dose of Bisphenols (BPs) due to their widely pervasiveness in the environment. BPs hold similar chemical structures to 17β-estradiol (E2) and thyroid hormone, thus posing threats to human health by rendering the endocrine system dysfunctional. Among BPs, Bisphenol-A (BPA) is the best-known and extensively studied endocrine disrupting compound (EDC). BPA possesses multisystem toxicity, including reproductive toxicity, neurotoxicity, hepatoxicity and nephrotoxicity. Particularly, the central nervous system (CNS), especially the developing one, is vulnerable to BPA exposure. This review describes our current knowledge of BPA toxicity and the related molecular mechanisms, with an emphasis on the role of Wnt signaling in the related processes. We also discuss the role of oxidative stress, endocrine signaling and epigenetics in the regulation of Wnt signaling by BPA exposure. In summary, dysfunction of Wnt signaling plays a key role in BPA toxicity and thus can be a potential target to alleviate EDCs induced damage to organisms.

IL-33 Accelerates Chronic Atrophic Gastritis through AMPK-ULK1 Axis Mediated Autolysosomal Degradation of GKN1

Chronic atrophic gastritis (CAG) is a complex disease characterized by atrophy and inflammation in gastric mucosal tissue, especially with high expression of interleukins. However, the interaction and mechanisms between interleukins and gastric mucosal epithelial cells in CAG remain largely elusive. Here, we elucidate that IL-33 stands out as the predominant inflammatory factor in CAG, and its expression is induced by H. pylori and MNNG through the ROS-STAT3 signaling pathway. Furthermore, our findings reveal that the IL-33/ST2 axis is intricately involved in the progression of CAG. Utilizing phosphoproteomics mass spectrometry, we demonstrate that IL-33 enhances autophagy in gastric epithelial cells through the phosphorylation of AMPK-ULK1 axis. Notably, inhibiting autophagy alleviates CAG severity, while augmentation of autophagy exacerbates the disease. Additionally, ROS scavenging emerges as a promising strategy to ameliorate CAG by reducing IL-33 expression and inhibiting autophagy. Intriguingly, IL-33 stimulation promotes GKN1 degradation through the autolysosomal pathway. Clinically, the combined measurement of IL-33 and GKN1 in serum shows potential as diagnostic markers. Our findings unveil an IL-33-AMPK-ULK1 regulatory mechanism governing GKN1 protein stability in CAG, presenting potential therapeutic targets for its treatment.

tRNA modification enzyme-dependent redox homeostasis regulates synapse formation and memory

Post-transcriptional modification of RNA regulates gene expression at multiple levels. ALKBH8 is a tRNA modifying enzyme that methylates wobble uridines in specific tRNAs to modulate translation. Through methylation of tRNA-selenocysteine, ALKBH8 promotes selenoprotein synthesis and regulates redox homeostasis. Pathogenic variants in ALKBH8 have been linked to intellectual disability disorders in the human population, but the role of ALKBH8 in the nervous system is unknown. Through in vivo studies in Drosophila, we show that ALKBH8 controls oxidative stress in the brain to restrain synaptic growth and support learning and memory. ALKBH8 null animals lack wobble uridine methylation and exhibit a global reduction in protein synthesis, including a specific decrease in selenoprotein levels. Loss of ALKBH8 or independent disruption of selenoprotein synthesis results in ectopic synapse formation. Genetic expression of antioxidant enzymes fully suppresses synaptic overgrowth in ALKBH8 null animals, confirming oxidative stress as the underlying cause of dysregulation. ALKBH8 animals also exhibit associative learning and memory impairments that are reversed by pharmacological antioxidant treatment. Together, these findings demonstrate the critical role of tRNA modification in redox homeostasis in the nervous system and reveal antioxidants as a potential therapy for ALKBH8-associated intellectual disability.

A novel multifunctional mitochondrion-targeting NIR fluorophore probe inhibits tumour proliferation and metastasis through the PPARγ/ROS/β-catenin pathway

Recent advancements in tumour-targeted therapies and immunotherapy offer hope to patients with various malignancies. However, the uncontrolled growth and metastatic infiltration of malignant tumours remain a huge therapeutic challenge. Therefore, this study aimed to develop an integrated multifunctional diagnostic and treatment reagent IR-251 that can not only be used for tumour imaging but also to inhibit tumour growth and metastasis. Besides, our results showed that IR-251 targeted and damaged the mitochondria in cancer cells via organic anion-transporting polypeptides. Mechanistically, IR-251 induced ROS overproduction by inhibiting PPARγ and then inhibiting the β-catenin signalling pathway and downstream protein molecules related to the cell cycle and metastasis. Moreover, the excellent anti-tumour proliferation and metastasis ability of IR-251 were verified in vitro/in vivo. And histochemistry staining revealed that IR-251 inhibited tumour proliferation and metastasis, which showed no significant side effect. In conclusion, this novel, multifunctional, mitochondria-targeting near-infrared fluorophore probe IR-251 has great potential in achieving accurate tumour imaging and inhibiting tumour proliferation and metastasis, and the underlying mechanism of action of IR-251 is mainly via the PPARγ/ROS/β-catenin pathway.

Methyltransferase Set7/9 as a Multifaceted Regulator of ROS Response

Reactive oxygen species (ROS) induce multiple signaling cascades in the cell and hence play an important role in the regulation of the cell's fate. ROS can cause irreversible damage to DNA and proteins resulting in cell death. Therefore, finely tuned regulatory mechanisms exist in evolutionarily diverse organisms that are aimed at the neutralization of ROS and its consequences with respect to cellular damage. The SET domain-containing lysine methyltransferase Set7/9 (KMT7, SETD7, SET7, SET9) post-translationally modifies several histones and non-histone proteins via monomethylation of the target lysines in a sequence-specific manner. In cellulo, the Set7/9-directed covalent modification of its substrates affects gene expression, cell cycle, energy metabolism, apoptosis, ROS, and DNA damage response. However, the in vivo role of Set7/9 remains enigmatic. In this review, we summarize the currently available information regarding the role of methyltransferase Set7/9 in the regulation of ROS-inducible molecular cascades in response to oxidative stress. We also highlight the in vivo importance of Set7/9 in ROS-related diseases.

Mitigation of nicotine-induced developmental effects by 24-epibrassinolide in zebrafish

Nicotine is a highly addictive substance that can cause teratogenic impacts in the embryo through redox-dependent pathways. As antioxidants, naturally occurring chemicals can protect cells from redox imbalance. The purpose of this study was to evaluate the effectiveness of 24-epibrassinolide (24-EPI), a natural brassinosteroid with well-known antioxidant properties, in protecting zebrafish embryos against nicotine's teratogenic effects. For 96 h, embryos (2 h post-fertilization - hpf) were exposed to 100 μM nicotine, co-exposed with 24-EPI (0.01, 0.1, and 1 μM), and 24-EPI alone (1 μM). Lethal and sublethal developmental characteristics were evaluated during exposure. Biochemical tests were performed at the conclusion of the exposure, and distinct behavioural paradigms were analysed 24 h later. Nicotine exposure resulted in a higher proportion of larvae with deformities, which were decreased following co-exposure to 24-EPI. Nicotine exposure also caused an increase in oxidative stress as observed by the increased activity of superoxide dismutase and catalase accompanied by an increase in the malondialdehyde levels. Besides, metabolic changes were noticed as observed by the increased lactate dehydrogenase activity that were hypothesised to be associated to nicotine-induced hypoxia which may be responsible for the increased oxidative damage. In addition, locomotor deficits were observed as well as a decrease in the acetylcholinesterase activity denoting nicotine-induced cognitive dysfunction. However, co-exposure to 24-EPI alleviated behavioural deficits and improved nicotine-induced emotional states. Overall, and although further studies are required to clarify these effects, 24-EPI showed promising ameliorative properties against the teratogenic effects induced by nicotine.