Nitric oxide signaling in health and disease

Nitric oxide: a gas transmitter in healthy and diseased skin

Numerous physiological processes in the human skin are mediated by nitric oxide, a gaseous signalling molecule. Almost every type of skin cell may produce nitric oxide, it is possible to generate nitric oxide without the need of enzymes. Nitric oxide plays a crucial role in regulating apoptosis, keratinocyte differentiation and proliferation, the protective properties of the epidermal barrier, and the structure and functions of the microcirculatory bed. Nitric oxide is involved in immunological and inflammatory responses, hair growth regulation, and wound healing processes. It mediates ultraviolet-induced processes such as erythema and edema development and participates in melanogenesis. Furthermore, the ability of nitric oxide to bind reactive oxygen species and prevent lipid peroxidation gives it antioxidant qualities. This coordinated action of nitric oxide on gene expression and membrane integrity effectively protects cells from ultraviolet A-induced apoptosis and necrosis. Furthermore, nitric oxide can be considered as a molecule that inhibits the development of cancer and photoaging. It directly harms microorganisms and indirectly activates the immune system, exhibiting antibacterial, antiviral, and antifungal qualities. Notably, nitric oxide is effective against antibiotics-resistant bacteria. All of the aforementioned findings suggest that nitric oxide is a gaseous mediator that can protect skin function.

Superoxide anion-responsive persulfide and all-trans retinoic acid co-donating peptide assemblies attenuate myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) has become a severe threat to human health due to its high mortality rate and poor prognosis. Mutually entangled issues including ROS over-production, excessive inflammatory responses, and myocardial apoptosis are involved during MIRI. Effective inhibition of ROS burst at the beginning of reperfusion has been proved as the key for MIRI treatment. In this work, we report a superoxide anion-responsive peptide co-assembly (S/A-P) capable of delivering the H2S donor (i.e., superoxide-responsive persulfide donor) and all-trans retinoic acid (ATRA) simultaneously for the treatment. Our results suggest that compared with its single peptidic counterparts, the as-prepared system can significantly lower ROS production and repair myocardial mitochondrial dysfunction due to the synergy effect from the persulfides/H2S and ATRA. Moreover, S/A-P can reduce excessive inflammatory response through regulating macrophage polarization, which is further mapped by RNA sequencing. In vivo assessment of the co-assembly also displays an excellent therapeutic effect of MIRI on rats. In terms of good biocompatibility and outstanding efficacy, we believe that S/A-P will have a bright future for the treatment of cardiovascular diseases or other related diseases.

Exploring medical gas therapy in hemorrhagic stroke treatment: A narrative review

Hemorrhagic stroke (HS) is a neurological disorder caused by the rupture of cerebral blood vessels, resulting in blood seeping into the brain parenchyma and causing varying degrees of neurological impairment, including intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH). Current treatment methods mainly include hematoma evacuation surgery and conservative treatment. However, these methods have limited efficacy in enhancing neurological function and prognosis. The current challenge in treating HS lies in inhibiting the occurrence and progression of secondary brain damage after bleeding, which is a key factor affecting the prognosis of HS patients. Studies have shown that medical gas therapy is gaining more attention and has demonstrated various levels of neuroprotective effects on central nervous system disorders, such as hyperbaric oxygen, hydrogen sulfide, nitric oxide, carbon monoxide, and other inhalable gas molecules. These medical gas molecules primarily improve brain tissue damage and neurological dysfunction by regulating inflammation, oxidative stress, apoptosis, and other processes. However, many of these medical gasses also possess neurotoxic properties. Therefore, the use of medical gases in HS deserves further exploration and research. In this review, we will elucidate the therapeutic effects and study the advances in medical gas molecules in HS.

Hybrid membrane based biomimetic nanodrug with high-efficient melanoma-homing and NIR-II laser-amplified peroxynitrite boost properties for enhancing antitumor therapy via effective immunoactivation

Owing to the excellent stability, anticancer activity and immunogenicity, peroxynitrite (ONOO-) has been gained enormous interests in cancer therapy. Nevertheless, precise delivery and control release of ONOO- in tumors remains a big challenge. Herein, B16F10 cancer cell membrane/liposome hybrid membrane (CM-Lip) based biomimetic nanodrug with high-efficient tumor-homing and NIR-II laser controlled ONOO- boost properties was designed for melanoma treatment. Briefly, NIR-II molecule IR1061, NO donor BNN6 and β-lapachone (Lapa) were firstly encapsulated in the heat-responsive palmitoyl phosphatidylcholine/cholesterol liposome, followed by fusion with B16F10 cell membrane (CM) to obtain biomimetic CM-Lip@(IR/BNN6/Lapa). The hybrid membrane-based nanodrug displayed excellent biocompatibility and melanoma-targeting efficiency. Upon 1064 nm laser irradiation, the mild photothermal effect of CM-Lip@(IR/BNN6/Lapa) firstly triggered the release of NO and Lapa, which subsequently catalyzed the quinone oxidoreductase 1 (NQO1) overexpressed in tumors to produce O2•-, finally caused intraturmal ONOO- boost via cascade reaction. The boosted ONOO- could effectively inhibit melanoma by ways of triggering mitochondrion-mediated apoptotic pathway, upregulating 3-nitrotyrosine expression, inducing DNA damage and inhibiting DNA repair enzyme expression of poly (ADP-ribose) polymerase 1 (PARP-1). Moreover, ONOO- displayed excellent immunoactivation and immunomodulation activities by effectively inducing immunogenic tumor cell death, promoting dendritic cells maturation, increasing cytotoxic T lymphocytes expression and repolarizing M1-phenotype macrophages.

Paracetamol: the potential therapeutic pathways defining its clinical use

The non-narcotic analgesic paracetamol is used as both an antipyretic and an analgesic. For mild-to-moderate pain, paracetamol is utilized; however, because it has no anti-inflammatory effect, it is not as effective as non-steroidal anti-inflammatory medicines (NSAIDs) as to reduce pain. Even while paracetamol is widely used and safe, its exact mechanism is still unknown. It has been shown that in addition to the well-established cyclooxygenase (COX) pathways, paracetamol and its metabolites can also modify other signaling pain pathways. The COX enzyme is inhibited by paracetamol either directly or indirectly through the activation of cannabinoid receptors (CB1R and CB2R) and transient receptor potential cation channel subfamily member 1 (TRPV1) by its metabolite N-arachidonoylphenolamine (AM404). Furthermore, paracetamol increases serotonin release, decreases serotonin metabolism, or blocks serotonin reuptake to boost serotonin levels in the brain. A small number of animal studies have suggested that COX-3, a brain-expressed COX-1 variation, may have a therapeutic role in the way paracetamol works. However, the COX-3 pathway alone cannot account for paracetamol's potent analgesic, antinociceptive, and antipyretic properties. The possible molecular routes of paracetamol with regard to its clinical applications are therefore revised in this review.

Discovery of an NF-κB1 p105 Degrader for Anti-Inflammatory Therapy via Structural Optimization of the Coumarin Natural Product Minutuminolate

In this study, the coumarin natural product minutuminolate (MNT) was used as a starting point for the development of anti-inflammatory agents. Through structure-activity relationship studies, a lead compound MD-1 was designed and synthesized, exhibiting significantly improved anti-inflammatory activities. Mechanistic studies revealed that MD-1 is a degrader of the p105 subunit of NF-κB. Gene knockdown experiments further showed that the Cullin-ring ligase (CRL) SCFβTrCP is involved in MD-1-induced p105 degradation. This leads to suppressed NF-κB transcriptional activity, which is consistent with its potent anti-inflammatory effects. Taken together, our work challenges the longstanding notion that NF-κB is undruggable, as we demonstrate that the p105 subunit of NF-κB is indeed tractable with small molecules. More importantly, our study highlights that natural products are valuable starting points for the discovery and development of anti-inflammatory agents with novel mechanisms of action.

Optimizing in vitro maturation of oocytes with nitric oxide-loaded microbubbles

Introduction

Nitric oxide (NO) plays a pivotal role in female reproductive processes, yet its clinical translation is limited by its short half-life and rapid systemic clearance. This study aimed to develop a stabilized NO delivery system to enhance oocyte maturation and quality for potential applications in assisted reproductive technologies (ART).

Methods

Lipid-based microbubbles (NO-MBs) were constructed via lyophilization to encapsulate and stabilize therapeutic NO gas. The effects of NO-MBs on in vitro oocyte maturation were evaluated using immature mouse oocytes, with conventional NO donors (e.g., SNP) as controls. Oocyte quality was assessed through Ca2+ levels, mitochondrial membrane potential (MMP), and intracellular reactive oxygen species (ROS). In vivo studies further examined oocyte retrieval, fertilization rates, and blastocyst cell apoptosis. Mechanistic investigations focused on the ERK signaling pathway.

Results

The key parameters of the optimized lipid-based microbubbles for NO gas delivery were as follows: particle concentration (2.23 × 10⁷ MBs/mL) and diameter (0.919 ± 0.807 μm). NO-MBs demonstrated superior biosafety and efficacy compared to conventional NO donors. In vitro, NO-MBs significantly increased the maturation rate of immature mouse oocytes (72.00% vs. 57.77% in controls) while improving oocyte quality, as evidenced by elevated Ca2+ levels, enhanced MMP, and reduced ROS. In vivo, NO-MBs enhanced oocyte retrieval and fertilization rates and reduced blastocyst cell apoptosis. Mechanistically, NO-MBs uniquely activated phosphorylated ERK, suggesting ERK pathway involvement in oocyte maturation.

Discussion

These findings highlight NO-MBs as a novel, clinically relevant strategy for targeted NO delivery in reproductive medicine. By optimizing NO release and bioavailability, NO-MBs offer a promising approach to improve oocyte quality and developmental outcomes in ART. Further studies are warranted to explore their broader applications in reproductive health.

Biological Models of Oxidative Purine DNA Damage in Neurodegenerative Disorders

Most DNA damage caused by oxidative metabolism consists of single lesions that can accumulate in tissues. This review focuses on two classes of lesions: the two 8-oxopurine (8-oxo-Pu) lesions that are repaired by the base excision repair (BER) enzyme and the four 5',8-cyclopurine (cPu) lesions that are repaired exclusively by the nucleotide excision repair (NER) enzyme. The aim is to correlate the simultaneous quantification of these two classes of lesions in the context of neurological disorders. The first half is a summary of reactive oxygen species (ROS) with particular attention to the pathways of hydroxyl radical (HO•) formation, followed by a summary of protocols for the quantification of six lesions and the biomimetic chemistry of the HO• radical with double-stranded oligonucleotides (ds-ODN) and calf thymus DNA (ct-DNA). The second half addresses two neurodegenerative diseases: xeroderma pigmentosum (XP) and Cockayne syndrome (CS). The quantitative data on the six lesions obtained from genomic and/or mitochondrial DNA extracts across several XP and CS cell lines are discussed. Oxidative stress contributes to oxidative DNA damage by resulting in the accumulation of cPu and 8-oxo-Pu in DNA. The formation of cPu is the postulated culprit inducing neurological symptoms associated with XP and CS.

NO Activates the Triterpenoid Biosynthetic Pathway in Inonotus obliquus Through Multilevel Signaling Regulation to Enhance Its Production

Triterpenoids are the bioactive components in Inonotus obliquus with extensive medicinal prospects, but their low content in fermentation production is the main limiting factor for their application. This study focuses on nitric oxide (NO), an important signaling molecule within organisms, aiming to explore its inducing effect on the synthesis of triterpenes in I. obliquus and the potential signaling transduction mechanisms involved. Compared with the control group, the content of representative triterpenoid betulin increased by 70.59% after adding the NO donor sodium nitroprusside. Gene expression level detection revealed that NO mainly promotes its biosynthesis by activating the transcription of key enzyme genes in the downstream pathway of betulin biosynthesis, thereby increasing its abundance. Tracing upstream, the NO signal was found to induce the upregulation of genes related to cellular antioxidant and calcium ion signaling pathways. Notably, IoCAMP responded strongly to the NO signal, participating in the regulation of cytoplasmic Ca2+ concentration by altering the Ca2+ concentration of mitochondria together with IoCATP and IoCALM. Additionally, the signaling of changes in Ca2+ concentrations is likely to crosstalk with the reactive oxygen species (ROS) signaling pathway. The increase in enzyme activity of IoNOX after NO induction confirmed the activation of the ROS signaling pathway. It works in synergy with IoSOD and IoCAT to reduce oxidative damage and promote downstream triterpenoid biosynthesis. This study not only contributes to clarify the signaling pathways regulating NO-mediated triterpenoid biosynthesis but also provides a theoretical basis for the efficient production of triterpenoid active components in I. obliquus.

Oxidative stress products and managements in atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disorder that affects a significant portion of the global population, severely impacting the quality of life and causing physical and psychological distress of patients. Oxidative stress, resulting from an imbalance between oxidation and antioxidation activities, plays a pivotal role in the pathogenesis of AD. Monitoring oxidative stress products can offer valuable insights into the development of AD and highlight essential clinical and therapeutic effects. Additionally, evidence suggests that antioxidant strategies can alleviate or avert oxidative damage induced by free radicals and offer significant promise in the treatment of AD. In addition to directly utilizing natural products and nanomaterials for antioxidant interventions, these can also be incorporated into hydrogels, which help repair the skin barrier and support the sustained release of therapeutic agents. Furthermore, microneedles provide a minimally invasive method for delivering antioxidants to the deeper layers of the skin, enhancing treatment efficacy. This review aims to summarize the role of the oxidative stress in the pathogenesis of AD, focusing in the main oxidative products (DNA, protein, and lipid oxidation products), as well as antioxidant therapeutic approaches involving natural products, nanomaterials, hydrogels, and microneedles. Understanding these biomarkers and antioxidant therapy approaches provides important insights into the management of AD.

Thiocarboxylate and Acid Chloride Mediated Generation of Nitric Oxide from a Dinickel(II)-Bis(ONO) Complex Involving the Formation of Perthionitrite and O-Nitrosyl Carboxylate

A detailed study for the generation of nitric oxide (NO) upon reaction of a binuclear Ni(II)-bis(ONO) complex with carboxylic acids (RCOOH, R = Me, Ph), thiols (RSH, R = Ph, p-F-C6H4), benzeneselenol (PhSeH), thiocarboxylates (RC(O)S-, R = Me, Ph), thiocarboxylic acids (RC(O)SH, R = Me, Ph), and acid chlorides (RC(O)Cl, R = Me, Ph) has been presented. The reactions of the binuclear Ni(II)-bis(ONO) complex with thiols/selenols give access to unusual dinickel(II)-nitrito-thiolato/selenolato complexes, while the reactions with RC(O)S-, RC(O)SH, and RC(O)Cl offer new mechanistic insights into the generation of perthionitrite (SSNO-) and O-nitrosyl carboxylates (RC(O)ONO), the well-known NO-carrying species in biology. Interestingly, while the reaction of the binuclear Ni(II)-bis(ONO) complex with RC(O)S- involved nucleophilic attack of the latter to the coordinated NO2- to generate SSNO-, the reaction with RC(O)Cl proceeds via the hitherto unknown nucleophilic attack of the coordinated NO2- to the carbonyl carbon of RC(O)Cl to generate RC(O)ONO, which, in turn, produces NO. The present comparative study thus demonstrates new reactions of metal-coordinated NO2- and detailed mechanistic investigations supported by molecular structure determinations and spectroscopic studies and establishes the hitherto unknown reaction of coordinated nitrite with RC(O)Cl to be a highly efficient method for the generation of NO in excellent yield.

Radiation-triggerable bioreactors enable bioenergetic reprograming of cancer stem cell plasticity via targeted arginine metabolism disruption for augmented radio-immunotherapy

Cancer stem cells (CSCs) are a major cause for the insufficient tumor eradication in the clinic, which universally present enhanced mitochondrial oxidative phosphorylation (OXPHOS) to facilitate stemness maintenance and drive treatment resistance. Herein, we report a nanointegrative radiation-triggerable bioreactor (RTB) that selectively remodels CSC-intrinsic arginine metabolism to bioenergetically reprogram CSCs towards a therapeutically-vulnerable differentiated state, leading to durable radio-immunotherapeutic responses in vivo. The RTB nanosystem was developed through the supramolecular integration of radioresponsive iNOS-expressing genetic circuits (pDNAiNOS) and β-lapachone (LAP) into CSC-targeting cationic liposomes. Low-dose radiotherapy (LDR)-induced Nrf2 upregulation readily activates pDNAiNOS to express excessive iNOS, which then depletes CSC-intrinsic arginine while generating abundant nitric oxide (NO) for in-situ amplification of LDR-mediated cytotoxicity. Meanwhile, LDR also upregulates NQO1 expression to promote LAP-mediated ROS generation. These effects could act in a cooperative manner to potently damage CSC mitochondria, which not only blocks OXPHOS activity to drive the differentiation of CSCs for abolishing their self-renewal and resistance capability, but also enhances their propensity towards immunogenic necroptosis to elicit adaptive antitumor immunity, showing significant potential for treating therapy-persistent tumors.

Current knowledge on the mechanisms underpinning vasculogenic mimicry in triple negative breast cancer and the emerging role of nitric oxide

Vasculogenic mimicry (VM) is the process by which cancer cells form vascular-like channels to support their growth and dissemination. These channels lack endothelial cells and are instead lined by the tumour cells themselves. VM was first reported in uveal melanomas but has since been associated with other aggressive solid tumours, such as triple-negative breast cancer (TNBC). In TNBC patients, VM is associated with tumour aggressiveness, drug resistance, metastatic burden, and poor prognosis. The lack of effective targeted therapies for TNBC has stimulated research on the mechanisms underpinning VM in order to identify novel druggable targets. In recent years, studies have highlighted the role of nitric oxide (NO), the NO synthesis inhibitor, asymmetric dimethylarginine (ADMA), and dimethylarginine dimethylaminohydrolase 1 (DDAH1), the key enzyme responsible for ADMA metabolism, in regulating VM. Specifically, NO inhibition through downregulation of DDAH1 and consequent accumulation of ADMA appears to be a promising strategy to suppress VM in TNBC. This review discusses the current knowledge regarding the molecular pathways underpinning VM in TNBC, anti-VM therapies under investigation, and the emerging role of NO regulation in VM.

A sequential stimuli-responsive hydrogel promotes structural and functional recovery of severe spinal cord injury

Utilizing drug-loaded hydrogels to restore nerve conductivity emerges as a promising strategy in the treatment of spinal cord injury (SCI). However, many of these hydrogels fail to deliver drugs on demand according to the dynamic SCI pathological features, resulting in poor functional recovery. Inspired by the post-SCI microenvironments, here we report a time-sequential and controllable drug delivery strategy using an injectable hydrogel responsive to reactive oxygen species (ROS) and matrix metalloproteinases (MMPs). This strategy includes two steps: first, the hydrogel responds to ROS and releases nanodrugs to scavenge ROS, thereby mitigating inflammation and protecting neurons from oxidative stress in the initial SCI stages; second, the accumulation of MMPs triggers the release of vascular endothelial growth factor from nanodrugs to promote angiogenesis and neural stem cell differentiation in the late stage of SCI. In two clinically relevant SCI models, a single injection of the hydrogel led to an efficient structural and functional recovery of SCI 6 weeks after the intervention. We observed less inflammation, fibrosis, and cavities but more angiogenesis and neurons in the hydrogel-treated injured spinal cord region compared with the untreated animals. The hydrogel exhibits mechanical strength and conductivity comparable to natural spinal cord, facilitating its further clinical translation.

Platelets from COVID-19 Patients Show an Altered Nitric Oxide/Reactive Oxygen Species Production Balance

Oxidative stress has been associated with COVID-19-related thrombotic complications. No investigations have explored nitric oxide (NO) and radical oxygen species (ROS) production by platelets. Indeed, activated platelets generate both NO and ROS which in turn regulate platelet function. The aim of the present study was to measure platelet NO and ROS production in COVID-19 patients, to assess whether they correlate with disease outcome and to clarify the mechanisms of platelet NO/ROS imbalance in COVID-19.Hospitalized mild and severe COVID-19 patients, age- and sex-matched healthy controls, and patients hospitalized in intensive care units for reasons different from COVID-19 were enrolled. Platelet NO and ROS production was assessed by flow cytometry. The oxidant and antioxidant capacity of COVID-19 plasma was assessed using lipid peroxidation and ORAC assays. The effect of COVID-19 plasma on platelet NO production and the impact of antioxidants on it were studied by flow cytometry.Platelets from COVID-19 patients displayed an altered NO/ROS balance, with defective NO and increased ROS production. Platelet NO production was significantly lower in patients who developed thrombotic events during hospitalization. COVID-19 patients showed significantly increased plasma lipid peroxidation and reduced antioxidant capacity compared with healthy controls. Concordantly, plasma from COVID-19 patients impaired NO production by healthy control species platelets, which was restored by the antioxidant agent Hydroxy-TEMPO.Our findings suggest that the unbalanced platelet NO/ROS production in COVID-19 plays a role in the thrombotic complications of SARS-CoV-2 infection. The restoration of platelet NO production may represent a therapeutic target for the prevention of thrombotic events in COVID-19 patients.

The Role of Oxidative Stress-Induced Senescence in the Pathogenesis of Preeclampsia

Preeclampsia is a hypertension condition of human pregnancy that poses a significant risk to pregnant women and their fetus. It complicates about 2-8% of human pregnancies worldwide and displays multifactorial pathogenesis, including increased placental oxidative stress because of disturbed utero-placental blood flow. Recent evidence suggests that increased oxidative stress promotes acceleration of the placental senescence which is implicated in the pathogenesis of preeclampsia. This review focuses on the mechanisms that lead to oxidative stress in preeclamptic patients and examines the role of oxidative stress-induced placental senescence in the pathogenesis of the disease.

In Vitro, Ex Vivo, and In Vivo Evidence of Nitrate-Reducing Activity in Levilactobacillus brevis CD2: A Potential Tool for Oral and Systemic Health Applications

Growing evidence supports the use of nitrate-reducing bacterial strains as probiotics to enhance the benefits of nitrate metabolism for both oral and systemic health. This study aimed to test the nitrate reductase activity of Levilactobacillus brevis CD2 (DSM-27961/CNCM I-5566), a strain widely used as a starter culture in fermented foods and recognized for its multifaceted health-promoting probiotic properties. We also sought to determine whether the probiotic lysate enhances nitrate reduction ex vivo using six salivary samples from healthy subjects while evaluating its potential influence on pH and buffering capacity. Considering the established link between lactate metabolism and nitrite production, we assessed the salivary levels of D-lactate after a 3-hour incubation with or without Lv. brevis. The results indicate that Lv. brevis CD2 exhibits significant intrinsic and concentration-dependent nitrate reductase activity. Additionally, treatment with Lv. brevis for 3 h significantly increased nitrite generation across all saliva samples, with further enhancement observed after the addition of exogenous nitrates. Lv. brevis also significantly improved salivary pH and buffering capacity, particularly when combined with nitrate. Furthermore, the probiotic treatment resulted in reduced levels of salivary D-lactate. To further support and validate our in vitro and ex vivo findings, we evaluated the oral nitrate-reducing activity in saliva samples from healthy individuals treated for four weeks with Lv. brevis CD2 lozenges. Of note, the results indicated that the probiotic group showed a significant increase in oral nitrate-reducing capacity compared to baseline and placebo after four weeks of treatment. Overall, our study suggests that Lv. brevis CD2 acts as a nitrate-reducing probiotic, providing new insights into its health benefits and complementing findings from previous studies.

Metal-Organic Frameworks: Unlocking New Frontiers in Cardiovascular Diagnosis and Therapy

Cardiovascular disease (CVD) is one of the most critical diseases which is the predominant cause of death in the world. Early screening and diagnosis of the disease and effective treatment after diagnosis play an important role in the patient's recovery. Metal-organic frameworks (MOFs), a kind of hybrid ordered micro or meso-porous materials, constructed by metal nodes or clusters with organic ligands, due to their special features like high porosity and specific surface area, open metal sites, or ligand tunability, are widely used in various areas including gas storage, catalysis, sensors, biomedicine. Recently, advances in MOFs are bringing new developments and opportunities for the healthcare industry including the theranostic of CVD. In this review, the applications of MOFs are illustrated in the diagnosis and therapy of CVD, including biomarker detection, imaging, drug delivery systems, therapeutic gas delivery platforms, and nanomedicine. Also, the toxicity and biocompatibility of MOFs are discussed. By providing a comprehensive summary of the role played by MOFs in the diagnosis and treatment of CVDs, it is hoped to promote the future applications of MOFs in disease theranostics, especially in CVDs.

Gold nanoparticle resveratrol complex increases apoptosis in KRAS mutant pancreatic cancer cells

The KRAS G12D mutation is the most prevalent type of pancreatic cancer and is found in about 35% of patients. Numerous natural chemicals are frequently investigated in cancer treatment to decrease side effects. Resveratrol (RVT) is a polyphenol that can promote cancer cell apoptosis and improve chemotherapy efficacy in cancers. To enhance delivery rate and efficacy, the size of about 30 nm gold nanoparticles (GNPs) was synthesized and conjugated to resveratrol via polyvinylpyrrolidone (GRs) for high bioavailability. Compared to RVT and GNPs, GRs had less inflammatory response and less toxicity on RAW 264.7 cells. This suggests that the toxicity of resveratrol can be alleviated by conjugation with gold nanoparticles. The viability of the human pancreatic cancer cell line (AsPC-1) decreased in sequence of GRs > RVT > GNPs, suggesting an enhanced anticancer effect of the GRs compared to resveratrol (RVT) alone. In addition, the extent of apoptosis was much bigger with GRs compared to RVT and GNPs. The apoptotic effects were confirmed with cell cycle arrest and expression of apoptosis-related genes and proteins. Thus, GRs had a better extent of anticancer effect than RVT, suggesting that GRs be considered as one of the prospective anti-cancer drugs for pancreatic cancer treatment.

Functional Nonheme Diiron(II) Complexes Catalyze the Direct Reduction of Nitrite to Nitric Oxide in Relevance to the Diiron Protein YtfE

The present work reports the functional modeling chemistry of YtfE, which features a nonheme diiron active site and mediates the direct reduction of NO2- to NO. The model complex, [Fe2(HPTP)Cl2]1+ (1), reduces NO2- to NO in a 100% yield within 12 h and generates [Fe4(HPTP)2(μ-O)3(μ-OH)]3+ (2). Similar to YtfE, the reaction involves stepwise oxidation of two Fe(II) centers and product (NO) inhibition, of which the latter produces [Fe2(HPTP)(NO)2Cl2]1+ (3). Complex 3 could also be synthesized by the reaction of [Fe2(HPTP)(NO)2(ClO4)]2+ (4) and chloride. Complex 1 catalyzes the reduction of NO2- to NO in the presence of PhS-, albeit with a low TON of 5, due to the formation of an insoluble product, [Fe2(HPTP)(μ-SPh)Cl2] (5). Another model complex [Fe2(HPTP)(OPr)]1+ (6), reduced NO2- to NO in an 80% yield after 24 h, generated [Fe2(HPTP)(OPr)(NO)2]1+ (7), and offered a TON of 19. The third model complex, [Fe2(HPTP)(ClO4)2]1+ (8), could reduce NO2- to NO in a 100% yield but only after 48 h. A comparison of these results establishes that easy oxidation of the Fe(II) centers, easy accessibility of the Fe(II) centers for the coordination of NO2-, and easy release of NO from the in situ generated dinitrosyl diiron complex increase the efficiency of the functional model complexes of YtfE.

GCH1 contributes to high-altitude adaptation in Tibetans by regulating blood nitric oxide

Nitric oxide (NO) is a key vasodilator that regulates vascular pressure and blood flow. Tibetans have developed a "blunted" mechanism for regulating NO levels at high altitude, with GTP cyclohydrolase 1 (GCH1) identified as a key candidate gene. Here, we present comprehensive genetic and functional analyses of GCH1, which exhibits strong Darwinian positive selection in Tibetans. We show that Tibetan-enriched GCH1 variants down-regulate its expression in the blood of Tibetans. Based on this observation, we generate the heterozygous Gch1 knockout (Gch1+/-) mouse model to simulate its downregulation in Tibetans. We find that under prolonged hypoxia, the Gch1+/- mice have relatively higher blood NO and blood oxygen saturation levels compared to the wild-type (WT) controls, providing better oxygen supplies to the cardiovascular and pulmonary systems. Markedly, hypoxia-induced cardiac hypertrophy and pulmonary remodeling are significantly attenuated in the Gch1+/- mice compared with the WT controls, likely due to the adaptive changes in molecular regulations related to metabolism, inflammation, circadian rhythm, extracellular matrix, and oxidative stress. This study sheds light on the role of GCH1 in regulating blood NO, contributing to the physiological adaptation of the cardiovascular and pulmonary systems in Tibetans at high altitude.

Aggregation-induced emission-based fluorescent probes for cellular microenvironment detection

The cellular microenvironment exerts a pivotal regulatory influence on cell survival, function, and behavior. Dynamic analysis and detection of the cellular microenvironment can promptly elucidate changes in cellular microenvironmental information, uncover the pathogenesis of diseases associated with aberrant microenvironments, and aid in predicting disease risk and monitoring disease progression. Aggregation-induced emission (AIE) fluorescent molecules possess unique AIE characteristics and offer significant advantages in imaging and sensing cellular microenvironments. In this review, we present a profile of the remarkable progress achieved in utilizing AIE fluorescent molecules for detecting cellular microenvironments in recent years. We particularly focus on AIE fluorescent probes applied in imaging key parameters of the cellular microenvironment, including pH, viscosity, polarity, and temperature, as well as in analyzing critical biological components of the microenvironment, such as gas signal molecules, metal ions, redox state, and proteins. We underscore the design principles, detection mechanisms, sensing performance, and biological applications of these fluorescent probes. Furthermore, we address the current challenges confronting this field and provide prospects for the future development of AIE probes used for microenvironment detection. We trust that this review will inspire researchers to develop more precise and sensitive AIE fluorescent probes for the detection of cellular microenvironments.

A Systematic Review of Endothelial Dysfunction in Chronic Venous Disease-Inflammation, Oxidative Stress, and Shear Stress

Chronic venous disease (CVD) is among the most common diseases in industrialized countries and has a significant socioeconomic impact. The diversity of clinical symptoms and manifestations of CVD pose major challenges in routine diagnosis and treatment. Despite the high prevalence and the huge number of venous surgical interventions performed every day, a substantial proportion of the etiopathogenesis remains unclear. There are several widely advocated and generally valid theories of "peri-capillary fibrin cuffs" and "white cell trapping hypothesis", which consider the role of venous reflux/obstruction, inflammation, vascular remodeling, hemodynamic changes, genetic and social risk factors. There are several specific provoking factors for the development of venous reflux: incompetence of the valve system, inflammation of the vascular wall, and venous hypertension. Over the past few years, increasing scientific data has demonstrated the link between oxidative stress, endothelial dysfunction, and vascular inflammation. High levels of oxidants and persistent inflammation can cause cumulative changes in hemodynamics, resulting in permanent and irreversible damage to the microcirculation and endothelial cells. Production of reactive oxygen species and expression of inflammatory cytokines and adhesion molecules are involved in a vicious cycle of venous wall remodeling. The interaction of ROS, and in particular, the superoxide anion radical, with nitric oxide leads to a decrease in NO bioavailability, followed by the initiation of prolonged vasoconstriction and hypoxia and impairment of vascular tone. This review addresses the role of ED, oxidative, and hemodynamic stress in the CVD mediation. Based on predefined inclusion and exclusion criteria, we conducted a systematic review of published scientific articles using PubMed, PMC Europe, Scopus, WoS, MEDLINE, and Google Scholar databases in the interval from 24 April 2002 to 1 April 2025. The current review included studies (n = 197) scientific articles, including new reviews, updates, and grey literature, which were evaluated according to eligibility criteria. The selection process was performed using a standardized form according to PRISMA rules, the manual search of the databases, and a double-check to ensure transparent and complete reporting of reviews. Studies had to report quantitative assessments of the relationship between vascular endothelial dysfunction, inflammation, oxidative stress, and shear stress in a chronic venous disease.

Associations between multiple ambient air pollutants, genetic risk, and incident mental disorders: An interaction study in the UK population

Mental disorders can be triggered by genetic and environmental risk factors. Limited studies have explored the effects of long-term exposure to air pollution on mental disorders, and most of the studies have focused on individual air pollutants. This study aimed to examine the relationship between long-term exposure to multiple air pollutants and incident mental disorders, including depression, anxiety, and schizophrenia, and whether the associations were affected by genetic susceptibility. Participants in the UK Biobank with no history of mental disorders were followed from baseline (2006 to 2010) to October 31st, 2022. Cox regression was applied to evaluate the correlation between PM2.5 absorbance, PM2.5, PM2.5-10, PM10, NO2, and NOx and any or specific mental disorders. Additive and multiplicative scales were used to measure the interaction between air pollution and schizophrenia polygenic risk score (PRS), depression PRS, or anxiety PRS on specific mental diseases. After a median of 13.36 years of follow-up on 252,376 participants, we observed per interquartile increase of PM2.5 absorbance (0.32 per meter), PM2.5 (1.28 μg/m3), NO2 (10.08 μg/m3), and NOx (16.78 μg/m3) were related to a 2-6 % higher risk of incident mental disorders. The HR (95 % CI) of incident mental disorder for the 2nd, 3rd, and 4th quartile of the air pollution score were 1.05 (1.01-1.18), 1.13 (1.09-1.18), and 1.14 (1.09-1.19), respectively, in comparison to the lowest level of the score. Per interquartile increase in the air pollution score was associated with a 6 %, 24 %, 4 %, and 6 % higher risk of incident mental disorders, schizophrenia, depression, and anxiety, respectively. No interaction between air pollution and genetic risk of schizophrenia, depression or anxiety on corresponding incident disorders was observed. These findings emphasize the importance of implementing air pollution control standards to decrease the burden of mental disorders.

Hydroxysafflor yellow A for ischemic heart diseases: a systematic review and meta-analysis of animal experiments

Background

Hydroxysafflor yellow A (HSYA) possesses a variety of pharmacological activities which has been demonstrated to be effective against ischemic heart disease (IHD). This study aimed to comprehensively examine the efficacy and summarize the potential mechanisms of HSYA against IHD in animal models.

Methods

We conducted electronic searches for preclinical studies on PubMed, Embase, Web of Science, Cochrane Library, CNKI, SinoMed, Wanfang, and Chinese VIP databases from inception to 31 January 2024. The CAMARADES checklist was chosen to assess the quality of evidence. STATA 14.0 software was utilized to analyze the data. The underlying mechanisms were categorized and summarized.

Results

Twenty-eight studies involving 686 rodents were included and the mean score of methodology quality was 5.04 (range from 4 to 7). Meta-analysis observed that HSYA could decrease myocardial infarction size (SMD: -2.82, 95%CI: -3.56 to -2.08, p < 0.001) and reduce the levels of biomarkers of myocardial injury including cTnI (SMD: -3.82, 95%CI: -5.20 to -2.44, p < 0.001) and CK-MB (SMD: -2.74, 95%CI: -3.58 to -1.91, p < 0.001). HSYA displayed an improvement in cardiac function indicators including LVEF, LVSP, +dp/dt max and -dp/dt max. Furthermore, HSYA was able to reduce the levels of MDA, TNF-α and IL-6, while increasing SOD and NO levels. Mechanistically, the protective effect of HSYA in alleviating myocardial injury after ischemia may be associated with NLRP3 inflammasome, Bcl-2, Bax, caspase-3, eNOS proteins, and TLR/NF-κB, Nrf2/HO-1, JAK/STAT, PI3K/Akt, AMPK/mTOR, VEGFA pathways.

Conclusion

This study demonstrates that HSYA exerts cardioprotective effects in decreasing infarct size, reducing myocardial enzymes and improving cardiac function, which may be mediated by anti-inflammatory, antioxidant, anti-apoptotic, regulation of autophagy, improvement of microcirculation and promotion of angiogenesis. However, the absence of safety assessment, lack of animal models of co-morbidities, and inconsistency between timing of administration and clinical practice are limitations of preclinical studies.

Systematic Review Registration

clinicaltrials.gov, Identifier, CRD42023460790.

Ultrasound-Driven Nitric Oxide Generation for Enhanced Sonodynamic-Photothermal Therapy

Recently, green gas therapy based on nitric oxide (NO) has gained considerable attention in cancer treatment. The supplementation of exogenous NO and its controlled release represent promising strategies for adjuvant tumor therapy. In this study, we developed a novel ultrasound (US)-triggered NO generation and release nanoplatform that integrates NO therapy, sonodynamic therapy, and photothermal therapy (PTT) into a collaborative therapeutic modality. An environmentally friendly biomacromolecule, polydopamine, was employed to coload chlorin e6 (Ce6) and NO donor (BNN6), resulting in the nanocomposite PDA-Ce6/BNN6 (PCB). A single US stimulus simultaneously activated Ce6 to produce reactive oxygen species (ROS) and promoted BNN6 to release NO. The dual effects of ultrasonic mechanical action and physiological modulation by NO substantially improved local vascular function and enhanced tumor cell permeability, thereby increasing the targeted accumulation of PCB within tumors. Reactive nitrogen species (RNS) derived from NO and ROS further exacerbated oxidative damage and enhanced the sensitivity of tumor cells to hyperthermia. Both in vitro and in vivo experiments demonstrated that ultrasonic stimulation of NO/ROS/RNS combined with PTT effectively inhibited tumor cell growth and proliferation. The findings suggest that NO gas therapy based on extracorporeal US can significantly amplify the efficacy of PTT and offer new insights for developing other combined strategies aimed at physically regulating deep tumors.

Ultrasound-Responsive 4D Bioscaffold for Synergistic Sonopiezoelectric-Gaseous Osteosarcoma Therapy and Enhanced Bone Regeneration

Various antitumor strategies have emerged to address the escalating need for effective tumor eradication. However, achieving precise and spatiotemporally controlled dynamic therapies remains promising yet challenging. Sonopiezoelectric nanotherapy eliminates tumor cells by generating reactive oxygen species (ROS) through ultrasound stimulation, enabling spatiotemporal control and ensuring safety during deep tissue penetration. In this study, a hybrid bioscaffold incorporating few-layer black phosphorus (BP) and nitric oxide (NO) donors are rationally designed and engineered for sonopiezoelectric-gaseous synergistic therapy. This ultrasound-responsive system provides a stepwise countermeasure against tumor invasion in bone tissues. Ultrasonic vibration induces mechanical strain in BP nanosheets, leading to piezoelectric polarization and subsequent ROS generation. Moreover, ultrasound-triggered NO burst release from the donors enables spatiotemporally controlled gas therapy. The synergistic effects of sonopiezoelectric therapy and ultrasound-excited gas therapy enhance tumor eradication, effectively inhibiting tumor proliferation and metastasis while minimizing off-target cytotoxicity. Additionally, the biomineralization capability of degradable BP and proangiogenic effects of low-concentration NO establish the hybrid bioscaffold as a bioactive platform that facilitates subsequent bone regeneration. The development of this 4D multifunctional therapeutic platform, characterized by superior sonopiezoelectric efficacy, controlled NO release, and stimulatory effects on tissue regeneration, offers new insights into the comprehensive treatment of invasive bone tumors.

Assessing the Antioxidant, Hepatoprotective, and Iron-Chelating Potential of Perilla frutescens Seed

Background/Objectives: Iron overload is a serious condition that can increase the production of reactive oxygen species (ROS), leading to oxidative tissue damage and organ dysfunction. While current pharmaceutical drugs for iron chelation have limitations, the search for natural herbs with iron-chelating properties is crucial. This study aimed to explore the various biological functions of the Perilla frutescens seed, regarding antioxidant activity and hepatoprotective and iron-chelating properties. Methods:Perilla frutescens seeds were subjected to extraction using a solvent-partitioning technique. Each fraction was evaluated for total phenolic content (TPC), total flavonoid content (TFC), and rosmarinic acid (RA) content by Folin-Ciocalteu assay, aluminum chloride colorimetric assay, and ultra-high-performance liquid chromatography (UHPLC), respectively. Antioxidant activity was assessed using DPPH, ABTS, and FRAP assays. The inhibition of lipid peroxidation was evaluated using the TBARS assay in HepG2 cells and an egg yolk model. The iron-chelating activity was examined using a ferric nitrilotriacetate (Fe3+-NTA)-binding assay, labile iron pool (LIP) level assessment, and the transferrin receptor (TfR) expression in HepG2 cells. Results: Phytochemical analysis indicated that the ethyl acetate (EtOAc) fraction had the highest TPC, TFC, and RA. This fraction demonstrated strong antioxidant properties and attenuated lipid peroxidation in HepG2 cells and egg yolk. In addition, this fraction exhibited iron-binding activity, decreased LIP levels, and induced TfR expression in iron-loaded HepG2 cells similar to the rosmarinic acid standard. Conclusions: These findings suggest that the EtOAc fraction of the Perilla frutescens seed possesses promising potential as a therapeutic agent for treating iron overload.

Eight weeks of high-intensity interval training alters the tongue microbiome and impacts nitrate and nitrite levels in previously sedentary men

Nitric oxide (∗NO) is a key signalling molecule, produced enzymatically via ∗NO synthases (NOS) or following the stepwise reduction of nitrate to nitrite via oral bacteria. Exercise training upregulates NOS expression and improves systemic health, but its effect on oral health, and more particularly the oral microbiome, has not been investigated. We used an exercise training study design to investigate changes in the tongue dorsum microbiome, and in nitrate and nitrite levels in the saliva, plasma and muscle, before, during and after an exercise training period. Eleven untrained males (age 25 ± 5 years, mass 64.0 ± 11.2 kg, stature 171 ± 6 cm, V˙ O2peak 2.25 ± 0.42 l min-1) underwent 8-weeks of high-intensity interval training (HIIT), followed by 12-weeks of detraining. The tongue dorsum microbiome was examined using Pac-Bio long-read 16S rRNA sequencing. Nitrate and nitrite levels were quantified with high-performance liquid chromatography. Grouped nitrite-producing species did not change between any timepoints. However, HIIT led to changes in the microbiome composition, increasing the relative abundance of some, but not all, nitrite-producing species. These changes included a decrease in the relative abundance of nitrite-producing Rothia and a decrease in Neisseria, alongside changes in 6 other bacteria at the genus level (all p ≤ 0.05). At the species level, the abundance of 9 bacteria increased post-training (all p ≤ 0.05), 5 of which have nitrite-producing capacity, including Rothia mucilaginosa and Streptococcus salivarius. Post-detraining, 6 nitrite-producing species remained elevated relative to baseline. Nitrate increased in plasma (p = 0.03) following training. Nitrite increased in the saliva after training (p = 0.02) but decreased in plasma (p = 0.03) and muscle (p = 0.002). High-intensity exercise training increased the abundance of several nitrite-producing bacteria and altered nitrate and nitrite levels in saliva, plasma, and muscle. Post-detraining, several nitrite-producing bacteria remained elevated relative to baseline, but no significant differences were detected in nitrate or nitrite levels. Switching from a sedentary to an active lifestyle alters both the microbiome of the tongue and the bioavailability of nitrate and nitrite, with potential implications for oral and systemic health.

The neuroprotective effect of human umbilical cord MSCs-derived secretome against α-synuclein aggregates on the blood-brain barrier

The blood-brain barrier (BBB) is a specialized network that maintains central nervous system homeostasis. Disruption of the BBB can lead to neuronal damage and contribute to neurodegenerative diseases like Parkinson's disease (PD), characterized by alpha-synuclein (αSN) aggregation, which forms intracellular inclusions. Mesenchymal stem cells (MSCs) have shown promise in alleviating the severity of neurological diseases through their paracrine secretions. However, the impact of MSCs secretome on the BBB remains largely unclear. In this study, we investigated the effect of human umbilical cord-derived MSCs (hUC-MSCs) secretome on the BBB in the presence of toxic αSN-aggregates (αSN-AGs). Using in vitro BBB models established through mono- and co-culture systems of hCMEC/D3 cells, we assessed the influence of the secretome on the cytotoxicity and inflammatory responses induced by αSN-AGs. Our results demonstrate that the hUC-MSCs secretome exerts protective effects by mitigating the toxic effects of αSN-AGs on the BBB. Specifically, this study shows a notable reduction in cytotoxicity and inflammation. Our findings highlight the potential of hUC-MSCs secretome as a promising candidate for innovative, cell-free therapies in PD treatment. Furthermore, we propose an optimized method for isolating MSCs from umbilical cord tissue, aimed at facilitating future research on the therapeutic applications of these cells.

The Role of Nitric Oxide in the Sweep Gas for Patients Receiving Extracorporeal Membrane Oxygenation or Cardiopulmonary Bypass

Nitric oxide (NO) was proclaimed the 1992 "molecule of the year" by Culotta in Science magazine because of its importance in neuroscience, physiology, and immunology. Inhaled NO has been in clinical use for over 35 years to decrease pulmonary hypertension and improve oxygenation. Over the past 20 years, there has been much research into understanding the role of NO on cell surface receptors, mitochondria, and intracellular processes that involve calcium and superoxide radicals. This research has shown that, irrespective of the cause, NO has a major role in the systemic inflammatory response syndrome and ischemia-reperfusion injury.1 More recent clinical research has focussed on NO use in patients undergoing cardiopulmonary bypass and receiving extracorporeal life support, with some centres incorporating NO into sweep gas as part of routine practice. In this article we review NO pathways in humans, the biologic effects of NO, the interplay between NO and red blood cells, and animal and human studies on the effects of exogenously administered NO.

NIR-triggered programmable nanomotor with H2S and NO generation for cascading oncotherapy by three-pronged reinforcing ICD

Gas therapy (GT) and/or phototherapy have been recently employed as immunogenic cell death (ICD) agents for activating immunotherapy, whereas the effective activation of sufficient immune responses remains an enormous challenge in such single therapeutic modality. In this study, a near-infrared (NIR)-triggered programmable nanomotor with hydrogen sulfide (H2S) and nitric oxide (NO) generation is well designed to achieve oncotherapy by cascading mild photothermal, gas, and reactive oxygen species (ROS)-reinforced immunogenic cell death. In brief, a gas signal molecule donor NOSH with H2S and NO capable of on-demand H2S and NO release was synthesized and then loaded into hollow mesoporous copper sulfide nanoparticles (termed as HCuSNPs) with an inherent NIR absorption and surface modification activity to obtain the programmable nanomotor (termed as NOSH@PEG-HCuSNPs). In particular, NOSH@PEG-HCuSNPs can effectively achieve the simultaneous spatiotemporal co-delivery of NOSH and HCuSNPs, thereby exerting the synergistic effects of GT and mild photothermal therapy (mPTT). It is worth noting that the anti-tumor response of mPTT is effectively enhanced by GT by disrupting the mitochondrial respiratory chain, inhibiting ATP production, and promoting tumor cell apoptosis. One by one, a large number of peroxynitrite anion (ONOO-) radicals are generated by the interactions of ROS from mPTT and NO from NOSH. Meanwhile, the unique protective mechanism of H2S is utilized to induce tumor thermal ablation by reducing the overexpression of heat shock protein 90 (HSP 90) and minimize the unnecessary damage toward normal tissues. Finally, ICD is markedly augmented by the cascading effects of mPTT, ONOO⁻radicals, and H2S. Concurrently, the immunosuppressive tumor microenvironment is reprogrammed, effectively inhibiting distant tumor tissues and preventing metastasis and tumor recurrence. Taken together, this study provides a new perspective for innovation in the field of oncotherapy.

A Light-Activatable Nitric Oxide Donor for Targeted Glaucoma Therapy with Real-Time Monitoring Capabilities

Primary open-angle glaucoma (POAG), the most common form of glaucoma, is characterized by a gradual increase in intraocular pressure (IOP). Nitric oxide (NO) donors are promising treatments for POAG, but their effectiveness requires selective NO release triggered by ocular-relevant stimuli. RhNO-Ab, a visible light-activatable NO donor and fluorescent probe is introduced. RhNO-Ab releases NO from its N-nitroso group and transforms from a non-fluorescent spirolactone to fluorescent Rhodamine (Rh) upon NO release. In vitro studies, including in bulk and single molecule level demonstrated a rapid NO release and fluorescence recovery upon light irradiation. Immunofluorescence shows enhanced delivery to target tissues of RhNO-Ab with ABCA1 antibody modification. Administration of RhNO-Ab with light at 30, 20, and 10 µm significantly reduces IOP in NOS3 KO mice by 2.11 mmHg (12.50%, n = 6), 1.77 mmHg (9.88%, n = 6), and 1.55 mmHg (8.23%, n = 6) 3 h post-treatment (*p < 0.05). RhNO-Ab with light also reduces transendothelial electrical resistance (TEER) in Schlemm's canal (SC) endothelial cells (n = 3, *p < 0.05) and upregulates soluble guanylate cyclase (sGC) mRNA and protein expression in mouse outflow tissues and human trabecular meshwork (HTM) cells. Unlike traditional NO donors, RhNO-Ab offers visible light-triggered therapeutic NO release and real-time monitoring, making it a promising novel strategy for POAG treatment.

Copper-nitrite complexes release nitric oxide and selectively induce oral precancer and cancer cell apoptosis

Nitric oxide (NO) is a small, short-lived gas molecule that influences various critical functions in living organisms. It involves multiple physiological processes, including cardiovascular function, metabolism, neurotransmission, immunity, and aberrant NO signaling leads to various disorders such as cardiovascular diseases, diabetes, and cancers. In this study, we explored the potential application of copper-nitrite complexes in treating oral precancer and cancer. The copper-nitrite complexes, L1Cu(NO2) and L2Cu(NO2), were shown to release NO into cells and selectively induce cytotoxicity to oral precancer and cancer cells. Notably, L1Cu(NO2) inhibited oral cancer cell proliferation by causing G0/G1 phase cell cycle arrest. Furthermore, L1Cu(NO2) induced cell apoptosis and upregulated the expression of p-PRAS40 (proline-rich Akt substrate of 40 kDa) in oral cancer cells. All these results reveal the therapeutic potential of copper-nitrite complexes, especially L1Cu(NO2), to be developed as a targeted therapy against oral precancer and cancer.

Bioactivities of Nostoc sp. polysaccharides: Anti-inflammatory, wound healing, cytoprotective, and anticoagulant effects

Polysaccharides from various cyanobacterial species have attracted attention for their potential health benefits. In this study, polysaccharide extracts from a freshwater Nostoc sp. were explored for their potential in immunomodulation relevant to skincare, and particularly wound care. Nostoc sp. polysaccharides (NSPs) were tested in various cellular and molecular assays using RAW264.7 macrophages and skin cell lines (HDF, HaCaT). Polysaccharides from the Nostoc sp. outer layer (OL) and inner fluid (IF) significantly enhanced cell proliferation and migration of HDF. HaCaT scratch-wound healing improved with certain polysaccharide extracts. Inner fluid fractions IF-2B and IF-3B polysaccharides demonstrated anti-inflammatory effects in RAW264.7 cells, while IF-1B reduced TNF-α and IL-8 expression in HaCaT cells. TNF-α, though not promoting cell proliferation, positively impacted phagocytosis and NO production. NSPs exhibited weak anticoagulation properties, and fraction IF-1B with monomer composition (Ara/3.0: Glc/23.7: Man/20.3: GlcA/28.0) accelerated wound healing; importantly, OL-1B along with all of the IF cold and hot-extracted fractions were non-cytotoxic, suggesting significant potential for developing skin therapeutics, including pharmaceutical and cosmetic products, based on active compounds from Nostoc sp.. The study underscores the underexplored potential of Nostoc sp. extracts in skincare and highlights the potential benefits of these bioactive components for therapeutic applications.

Role of Endothelin-1 and Nitric Oxide in Acute Ischemic Stroke Leptomeningeal Collateral Activation

Good leptomeningeal collaterals (LMCs) after large vessel occlusion (LVO) extend the time window for endovascular therapy. The mechanisms regulating LMC activation are not fully understood. The aim of this study was to investigate the potential role of two vasoactive molecules endothelin-1 (ET-1)-a vasoconstrictor agent-and nitric oxide (NO)-a vasodilator agent-in the regulation of post-stroke LMCs. Ischemic stroke patients within 6 h of LVO were included. Collateral status was assessed using the Menon scoring system based on computed tomography angiography scans. Patients were accordingly divided into three groups: poor, intermediate, and good LMCs. Recanalization was evaluated using the modified thrombolysis in cerebral infarction (mTICI) score. Serum levels of ET-1 and NO were measured at three time points: T0 (<6 h), T1 (24 h), and T2 (48 h). A total of 105 patients were enrolled (mean age 76 ± 12.8 years): 44 with good (46.2%), 36 with intermediate (37.8%), and 22 with poor LMCs (23.1%). NO values decreased, whereas ET-1 values increased from T0 to T1 in all groups of patients. No significant association was found between serum ET-1 levels and collateral status. Higher ET-1 levels at T1 correlated with poor outcome regardless of the LMC status or the degree of recanalization (p = 0.030). A significant linear positive correlation was revealed at T0 between high levels of ET-1 and the neutrophil count (Spearman's rho = 0.236, p = 0.035). Subgroup analysis showed a significant inverse correlation at T1 between NO and the collateral score (Spearman's rho = -0.251, p = 0.021). Although we observed no significant association between LMC score and serum ET-1 concentrations, at 24 h higher ET-1 serum levels were predictive of poor outcome and higher NO levels were correlated with poor collateral status. These findings may indicate an inadequate microvascular reperfusion, possibly due to ET-1-mediated vasoconstriction, neutrophil activation, and NO-mediated oxidative stress, suggesting their potential role in the no-reflow phenomenon.

Intestinal microbiota affects the progression of colorectal cancer by participating in the host intestinal arginine catabolism

Arginine plays a critical role in colorectal cancer (CRC) progression. We find that arginine catabolism is reduced in the intestinal microbiota of patients with CRC but increased in tumor tissue. We further verify that Escherichia coli can consume arginine via the arginine succinyltransferase (AST) pathway, and gavaging mice with the AST-deficient E. coli Nissle 1917 (ΔacEcN) can inhibit arginine catabolism of the intestinal microbiota, thereby increasing the arginine concentration in the colon. In the azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced CRC mouse model, reduced arginine catabolism in the intestinal microbiota increases the arginine concentration in the tumor microenvironment, thereby activating the nitric oxide (NO) synthesis pathway and polyamine synthesis pathway in tumor tissues, stimulating angiogenesis in the tumor microenvironment, inducing M2 macrophage polarization, and activating the Wingless/Integrated (Wnt)/β-catenin pathway, ultimately accelerating CRC progression. This study reveals that intestinal microbiota can affect CRC progression through arginine catabolism, providing a potential target for the prevention and therapy of CRC.

Large-sized and highly crystalline ceria nanorods with abundant Ce3+ species achieve efficient intracellular ROS scavenging

Intracellular reactive oxygen species (ROS) are associated with various inflammatory physiological processes and diseases, highlighting the need for their regulation to mitigate the detrimental effects of oxidative stress and to reduce cellular damage and disease progression. Here, we demonstrate cerium oxide (ceria) nanorods synthesized using a sol-gel method followed by heat treatment, called "AHT-CeNRs", as an efficient intracellular ROS scavenger. The synthesized AHT-CeNRs exhibited exceptional superoxide dismutase (SOD) and catalase (CAT)-like activities, both of which are crucial for converting ROS into harmless products. This was attributed to their high crystallinity, large surface area, numerous defects including oxygen vacancies, and abundant Ce3+ species. AHT-CeNRs exhibited higher CAT-like activities than natural CAT and conventional nanozymes, with a more than five-fold lower Km. When tested on HaCaT human keratinocyte cells, AHT-CeNRs primarily localized to the membrane but effectively scavenged intracellular ROS, potentially through their transmembrane catalytic action without disrupting the membrane. This contrasts with conventional antioxidant nanoparticles that act within the cytosol after penetrating the plasma membrane. AHT-CeNRs maintained cell viability by efficiently scavenging ROS, resulting in approximately 4-fold and 2-fold lower levels of inducible nitric oxide synthase (iNOS) and lactate dehydrogenase (LDH) compared to those in ROS-induced inflammation-stimulator lipopolysaccharide (LPS)-treated control groups, respectively. This simple yet effective method for intracellular ROS scavenging using AHT-CeNRs holds great potential for applications in cell and in vivo therapeutics to regulate intracellular ROS levels.

The involvement of Apolipophorin-III in orchestrating prophenoloxidase activation and NO production in Ostrinia furnacalis larvae

Apolipophorin-III (ApoLp-III), a multifunctional protein with lipid transport and immune defense functions, widely exists in insects. Although the function of ApoLp-III as a pattern recognition receptor (PRR) in immunity has been relatively studied, the immune response mediated by ApoLp-III is still vague. To understand whether ApoLp-III is involved in the activation of the prophenoloxidase-activating system (PPO-AS), we examined the production of nitric oxide (NO), and the synthesis of antimicrobial peptides after immune recognition. The larvae of lepidopteran pest Ostrinia furnacalis were used as a model to address these questions by detecting the changes of phenoloxidase (PO) activity and NO concentration after the knockdown of OfApoLp-III and bacterial infections. In the present study, we reported the cloning and characterization of the OfApoLp-III complementary DNA, and found that OfApoLp-III is mainly expressed in the larval fat body. These investigations revealed that OfApoLp-III was an immune-related gene, its knockdown reduced the PO activity by 41.9%, and NO concentration reached 2.7-fold higher level than that after double-stranded GFP treatment. Our data indicated that OfApoLp-III was involved in increased expression of Moricin, activation of PPO, and reduction of NO production in O. furnacalis larvae after different bacterial infections, which were required for innate immunity. ApoLp-III is a candidate target for an integrated pest control strategy using the combined application of double-stranded RNA and biocontrol bacteria.

Salivary-Gland-Mediated Nitrate Recirculation as a Modulator for Cardiovascular Diseases

Cardiovascular diseases (CVDs), which include multiple disorders of the heart and blood vessels, are the leading causes of death. Nitric oxide (NO) is a vasodilator that regulates vascular tension. Endogenous NO is produced via the L-arginine-nitric oxide synthase (NOS) pathway. In conditions of cardiovascular dysfunction, NOS activity is impaired, leading to NO deficiency. In turn, the reduction in NO bioactivity exacerbates the pathogenesis of CVDs. Exogenous intake of inorganic nitrate supplements endogenous production via the nitrate-nitrite-NO pathway to maintain the NO supply. Salivary glands play an essential role in the conversion of nitrate to NO, with approximately 25% of circulating nitrate being absorbed and secreted into saliva. As a result, salivary nitrate concentrations can exceed that in the blood by more than tenfold. This recycled nitrate in saliva serves as a reservoir for NO and performs NO-like functions when endogenous NO production is insufficient. In this review, we summarize the emerging benefits of dietary nitrate in CVDs, with a particular focus on salivary-gland-mediated nitrate recirculation in maintaining NO bioavailability and cardiovascular homeostasis. Salivary-gland-mediated nitrate recirculation provides a novel perspective for potential intervention of CVDs.

Identification of nitric oxide-related key genes in pulmonary hypertension via bioinformatics and in vitro validation for therapeutic target discovery

This study aims to uncover key genes and associated pathways related to nitric oxide (NO) in pulmonary hypertension (PH). By analyzing datasets GSE131793 and GSE703 from the Gene Expression Omnibus (GEO), differentially expressed genes (DEGs) associated with PH were identified. NO-related genes were selected from the GeneCards database and intersected with the DEGs. Subsequently, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were conducted to evaluate pathway enrichment, and key genes were selected using the random forest and least absolute shrinkage and selection operator (LASSO) regression algorithms. Immune cell infiltration was analyzed using the CIBERSORT algorithm, and Gene Set Enrichment Analysis (GSEA) was performed to explore potential mechanisms. The transcriptional regulatory networks of key genes were constructed using Cytoscape software. The expression levels of the key genes were validated in peripheral blood samples from PH patients using quantitative real-time PCR (RT-qPCR). A total of 97 DEGs were identified, of which 20 were NO-related genes. Three key genes, HBG2, PRKAB1, and THBD, were further selected. RT-qPCR results revealed significant upregulation of HBG2 and THBD, and downregulation of PRKAB1 in PH patients. CIBERSORT analysis indicated the significant role of immune cells in the pathology of PH. GSEA and transcriptional network analyses further suggested that key genes may participate in the pathogenesis of PH through immune regulation and metabolic pathways. Through bioinformatics analysis and clinical sample validation, this study systematically elucidates the potential mechanisms of NO-related key genes in PH, providing new molecular targets for early diagnosis and targeted therapy of PH.

S-Nitrosoglutathione Is Not a Substrate of OATP1B1, but Stimulates Its Expression and Activity

S-nitrosoglutathione (GSNO) is the S-nitrosated derivative of glutathione (GSH). GSNO is an endogenous class of NO donors and a natural NO depot in biological systems. Organic anion transporting polypeptide 1B1 (OATP1B1) is an influx transporter that is expressed in the liver. OATP1B1 plays an important role in the transport of endogenous and exogenous substances. Various pathways for the regulation of OATP1B1 have been described. In the present study, the involvement of OATP1B1 in GSNO transport and the regulation of OATP1B1 by GSNO was examined. For HEK293-OATP1B1, it has been shown that GSNO is not a substrate of OATP1B1, but OATP1B1 can participate in the transport of GSH across the cell membrane. GSNO at concentrations of 1-100 μM and exposure for 3 h do not affect the expression and activity of OATP1B1, but exposure for 24 and 72 h stimulates the expression of the SLCO1B1 gene, OATP1B1, and transporter activity. Up-regulation of OATP1B1 by GSNO is carried out through the NO-cGMP signaling pathway, Nrf2, and LXRa.

Effects of exercise training on nitric oxide metabolites in heart failure with reduced or preserved ejection fraction: a secondary analysis of the SMARTEX-HF and OptimEx-Clin trials

AIMS

Exercise has been shown to affect the nitric oxide (NO) pathway, which is involved in the pathophysiology of endothelial dysfunction in heart failure (HF) with reduced (HFrEF) and preserved ejection fraction (HFpEF). However, the effects of different exercise modes on NO metabolites in patients with HF are uncertain.

METHODS

Blood samples from two randomized controlled HF trials evaluating 1.) high-intensity-interval-training (HIIT), 2.) moderate-continuous-training (MCT) or 3.) a control group (CG) in HFrEF (SMARTEX-HF) and HFpEF (OptimEx-Clin) were analysed for NO metabolites L-arginine, homoarginine (hArg), asymmetric and symmetric dimethylarginine (ADMA; SDMA). Metabolite plasma concentrations were compared between HFrEF and HFpEF at baseline and within each HF type after 3 months of supervised exercise training and 12 month-follow-up.

RESULTS

Overall, 206 patients with HFrEF (61±12 years, 18.9% females) and 160 with HFpEF (70±8 years, 65.6% females) were investigated. Baseline hArg (1.74±0.78 vs. 1.31±0.69 µmol/l) and ADMA (0.68±0.15 vs. 0.62±0.09 µmol/l) were significantly higher in HFrEF (p<0.001). NO metabolites showed several significant associations with markers of HF severity like exercise capacity (VO2peak) and NT-proBNP, but not with measures of endothelial function (reactive hyperaemia index, flow-mediated dilation). After 3 months of exercise and 12-month-follow-up, changes in metabolite plasma levels were not significantly different between study groups (HIIT, MCT or CG) (pgroup*time >0.05), neither in HFrEF nor HFpEF.

CONCLUSION

Baseline NO metabolite profile was unfavourable in patients with HF and lower VO2peak or higher NT-proBNP. We did not find a significant influence of HIIT or MCT on NO metabolites at 3 and 12 months.

Reassessing the role of nitric oxide in the pathogenesis of sphincter of Oddi dysfunction

The pathogenic mechanisms underlying sphincter of Oddi dysfunction (SOD) remain incompletely understood, and it often leads to severe symptoms encompassing nausea, vomiting, and abdominal pain. New evidence now suggests correlations between nitric oxide (NO) and SOD. In this review, we summarized the factors influencing SOD pathogenesis via NO and its derivative, the peroxynitrite anion. NO appears to enhance SOD progression by modulating sphincter of Oddi (SO) contractions via NO-sGC-cGMP signaling or inducing the apoptosis of enteric neurons, interstitial cells of Cajal, smooth muscle cells, and other cellular components via peroxynitrite anion-mediated organelle damage. Thus, a comprehensive understanding of SOD will provide a foundation for the identification of potential drugs and treatment approaches.

A Fluorescent Probe for Imaging and Treating S-Nitrosation Stress in OGD/R Cells

Protein S-nitrosation, a redox post-translational modification elicited by nitric oxide (NO), is essential for modulating diverse protein functions and signaling pathways. Dysregulation of S-nitrosation is implicated in various pathological processes, including oxygen-glucose deprivation/reperfusion (OGD/R) injury, a widely used model for ischemia-reperfusion diseases. The dynamic changes in S-nitrosothiols (SNOs) during ischemia-reperfusion highlight the need for theranostic strategies to monitor and modulate SNO levels based on pathological progression. However, to date, no theranostic strategies have been reported for addressing dysregulated SNO in disease models, particularly in OGD/R conditions. Here, we report the development of a selective probe P-EHC, which could specifically react with SNOs to release EHC, not only exhibiting turn-on fluorescence with high quantum yield and good water solubility but also demonstrating macrophage migration inhibitory factor (MIF) inhibitory activity. In an OGD/R model of SH-SY5Y cells, we observed elevated SNO levels by using live-cell confocal imaging. Treatment of P-EHC significantly reduced intracellular reactive oxygen species (ROS), lowered total NOx species, and improved cell viability in the OGD/R model. In summary, the simplicity and versatility of P-EHC suggest its broad applicability for monitoring SNO in various biological models and therapeutic contexts, particularly in ischemia-reperfusion diseases.

Nitric oxide and peroxynitrite as new biomarkers for early diagnosis of autism

Autism spectrum disorder, or autism, is a neurodevelopmental disorder of the developing child's brain with a genetic causality. It can be diagnosed at about three years after birth when it begins to present itself via a range of neuropsychiatric symptoms. Nitric oxide is a crucial small molecule of life synthesized within cells of our body systems, including cells of our brain. Peroxynitrite is the product of reaction between superoxide anion and nitric oxide. It normally isomerizes into harmless nitrates or nitrites. However, when excessive superoxide anion is present, the cellular concentration of peroxynitrite can increase to a toxic level. Autism has been suggested to cause oxidative damage to brain cells. Until now, it is impossible to sample tissue from a live brain. Instead, stem cells can be derived (from an autism patient's somatic cells) which can then be differentiated and chemically directed to grow into miniature 3-dimensional tissue masses resembling specific brain regions (e.g., the cortex) called brain organoids. This review discusses utilizing nitric oxide and peroxynitrite as biomarkers and comparing their relative concentrations in stem cells and stem cell derived brain organoids of healthy and autistic individuals to develop a bioanalytical process for early diagnosis of autism.

Nitric oxide: Potential therapeutic target in Heat Stress-induced Multiple Organ Dysfunction

As climate change intensifies, urgent action is needed to address global warming and its associated health risks, particularly in vulnerable regions. Rising global temperature and increasing frequency of heatwaves present a hidden health risk, disrupting the body's temperature regulation and leading to severe consequences such as heat stress-induced multiple organ dysfunction (HS-MOD). Multiple organ injury triggered by heat stress involves complex molecular pathways such as nitric oxide dysregulation, inflammation, oxidative stress, mitochondrial dysfunction, calcium homeostasis disruption, and autophagy impairment that contribute to cellular damage. Understanding these molecular pathways is crucial for developing targeted therapeutic interventions to alleviate the impact of heat stress (HS). As we explore numerous therapeutic strategies, a remarkable molecule captures our attention: nitric oxide (NO). This colorless gas, mainly produced by nitric oxide synthase (NOS) enzymes, plays crucial roles in various body functions. From promoting vasodilation and neurotransmission to regulating the immune response, platelet function, cell signaling, and reproductive health, NO stands out for its versatility. Exploring it as a promising treatment for heat stress-induced multiple organ injury highlights its distinctive features in the journey towards effective therapeutic interventions. This involves exploring both pharmacological avenues, considering the use of NO donors and antioxidants, and non-pharmacological strategies, such as adopting nitrate-rich diets and engaging in exercise regimens. This review highlights the concept of heat stress, the molecular framework of the disease, and treatment options based upon some new interventions.

Advancements in NADH Oxidase Nanozymes: Bridging Nanotechnology and Biomedical Applications

Nicotinamide adenine dinucleotide (NADH) oxidase (NOX) is key in converting NADH to NAD+, crucial for various biochemical pathways. However, natural NOXs are costly and unstable. NOX nanozymes offer a promising alternative with potential applications in bio-sensing, antibacterial treatments, anti-aging, and anticancer therapies. This review provides a comprehensive overview of the types, functional mechanisms, biomedical applications, and future research perspectives of NOX nanozymes. It also addresses the primary challenges and future directions in the research and development of NOX nanozymes, underscoring the critical need for continued investigation in this promising area. These challenges include optimizing the catalytic efficiency, ensuring biocompatibility, and achieving targeted delivery and controlled activity within biological systems. Additionally, the exploration of novel materials and hybrid structures holds great potential for enhancing the functional capabilities of NOX nanozymes. Future research directions can involve integrating advanced computational modeling with experimental techniques to better understand the underlying mechanisms and to design more effective nanozyme candidates. Collaborative efforts across disciplines such as nanotechnology, biochemistry, and medicine will be essential to unlock the full potential of NOX nanozymes in future biomedical applications.