Nitric Oxide Synthase Expression Research Articles

Role of inducible nitric oxide (iNOS) and nitrosative stress in regulating sex differences in secondary lymphedema

Secondary lymphedema is a common complication following surgical treatment of solid tumors. Although more prevalent in women due to higher breast cancer rates, men also develop lymphedema, often with more severe manifestations. Despite these differences in clinical presentation, the cellular mechanisms underlying sex differences are poorly understood. Previous studies have shown that inducible nitric oxide synthase (iNOS) expression by inflammatory cells is an important regulator of lymphatic pumping and leakiness in lymphedema and that lymphatic endothelial cells are highly sensitive to nitrosative stress. Based on this rationale, we used a mouse tail model of lymphedema to study the role of nitric oxide in sex-related differences in disease severity. Consistent with clinical findings, we found that male mice have significantly worse tail edema and higher rates of tail necrosis compared with female mice following tail skin/lymphatic excision (p = 0.001). Our findings correlated with increased tissue infiltration of iNOS + inflammatory cells, increased iNOS protein expression, and increased nitrosative stress in male mouse lymphedematous skin tissues (p < 0.05). Importantly, transgenic male mice lacking the iNOS gene (iNOS-KO) displayed markedly reduced swelling, inflammation, and tissue necrosis rates, whereas no differences were observed between wild-type and iNOS-KO female mice. Overall, our results indicate that iNOS-mediated nitric oxide production contributes to sex-based differences in secondary lymphedema severity, emphasizing the need to consider sex as a biological variable in lymphedema research.

Sorbus commixta Fruit Extract Suppresses Lipopolysaccharide-Induced Neuroinflammation in BV-2 Microglia Cells via the MAPK and NF-κB Signaling Pathways

Sorbus commixta Hedl. is a traditional medicinal plant in Korea, China, and Japan with known antioxidative, anti-inflammatory, anti-atherogenic, and anti-melanin activities. However, its anti-neuroinflammatory effects remain largely unknown. In this study, we investigated the inhibitory effects of S. commixta fruit extracts on lipopolysaccharide-stimulated pro-inflammatory factors in BV-2 microglia. We compared the anti-neuroinflammatory activity of S. commixta fruit water extract (SFW) and 70% ethanol extract using a nitric oxide assay. Our data indicated that the SFW (25–100 μg/mL) treatment significantly inhibited excessive nitric oxide production in lipopolysaccharide-stimulated BV-2 microglia compared to the 70% ethanol extract. It also attenuated the expression of inducible nitric oxide synthase, cyclooxygenase-2, and pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor α. Moreover, SFW exhibited its anti-inflammatory properties by downregulating the expression of factors involved in the extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinase pathways and by suppressing nuclear factor kappa B. Caffeic acid was identified as a primary component of SFW showing anti-neuroinflammatory activity. These findings suggest that SFW may offer substantial therapeutic potential for the treatment of neurodegenerative diseases involving microglia activation.

Anti-Inflammatory Effects of Apostichopus japonicus Extract in Porphyromonas gingivalis-Stimulated RAW 264.7 Cells

Apostichopus japonicus has been used both as a food and in traditional medicine. However, its anti-inflammatory effects in periodontal diseases have not been studied. We examined the anti-inflammatory properties of Apostichopus japonicus extract in RAW 264.7 cells stimulated by Porphyromonas gingivalis. The cytotoxicity of Apostichopus japonicus extract was evaluated using the MTS assay. Its effect on NO production was then measured using the NO assay. The mRNA expression of inducible nitric oxide synthase (iNOS) and the pro-inflammatory cytokines IL-1β and IL-6 were assessed using quantitative real-time PCR (qRT-PCR). Western blotting was performed to investigate the expression of regulatory proteins involved in the NF-κB and MAPK signaling pathways. Apostichopus japonicus extract significantly inhibited NO production without cytotoxicity in RAW 264.7 cells. Following Porphyromonas gingivalis stimulation, treatment with the extract decreased iNOS mRNA expression and protein levels, which are responsible for NO production. The extract also suppressed the mRNA expression of pro-inflammatory cytokines. Additionally, Apostichopus japonicus extract inhibited NF-κB activation by regulating signaling molecules such as IKK and IκBα, while also preventing the phosphorylation of MAPK, including ERK, p38, and JNK, showing anti-inflammatory potential. Therefore, it may be a promising natural candidate for the development of new preventive and therapeutic strategies for periodontitis.

Pinus densiflora Root Extract Attenuates Osteoarthritis Progression by Inhibiting Inflammation and Cartilage Degradation in Interleukin-1β and Monosodium Iodoacetate-Induced Osteoarthritis Models.

Osteoarthritis (OA) is a common degenerative joint condition caused by an imbalance between cartilage synthesis and degradation, which disrupts joint homeostasis. This study investigated the anti-inflammatory and joint-improving effects of Pinus densiflora root extract powder (PDREP) in both in vitro and in vivo OA models. In an in vitro OA model, in which SW1353 human chondrosarcoma cells were treated with interleukin (IL)-1β, PDREP treatment significantly reduced the mRNA levels of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 while enhancing collagen type II alpha 1 (Col2a1) mRNA level, and decreased IL-6 and prostaglandin E2 (PGE2) levels. In addition, PDREP inhibited the phosphorylation of extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinase (JNK), p38, nuclear factor-kappa B (NF-κB), and the expression of inducible nitric oxide synthase (iNOS). In a monosodium iodoacetate (MIA)-induced OA rat model, the administration of PDREP resulted in decreased OA clinical indices, improved weight-bearing indices and gait patterns, reduced histological damage, and lowered serum inflammatory cytokine and MMPs expression. Furthermore, PDREP downregulated the phosphorylation of ERK, JNK, p38, and NF-κB, as well as the expression of iNOS, consistent with the in vitro findings. These results suggest that PDREP exhibits anti-inflammatory and joint-improving effects and has potential as a therapeutic strategy or functional food for the treatment of OA.

Retinoic acid ameliorates rheumatoid arthritis by attenuating inflammation and modulating macrophage polarization through MKP-1/MAPK signaling pathway.

Macrophages are innate immune cells connected with the development of inflammation. Retinoic acid has previously been proved to have anti-inflammatory and anti-arthritic properties. However, the exact mechanism through which retinoic acid modulates arthritis remains unclear. This study aimed to investigate whether retinoic acid ameliorates rheumatoid arthritis by modulating macrophage polarization. This study used retinoic acid to treat mice with adjuvant arthritis and evaluated anti-inflammatory effects by arthritis score, thermal nociceptive sensitization test, histopathologic examination and immunofluorescence assays. In addition, its specific anti-arthritic mechanism was investigated by flow cytometry, cell transfection and inflammatory signaling pathway assays in RAW264.7 macrophages in vitro. Retinoic acid significantly relieved joint pain and attenuated inflammatory cell infiltration in mice. Furthermore, this treatment modulated peritoneal macrophage polarization, increased levels of arginase 1, as well as decreased inducible nitric oxide synthase expression. In vitro, we verified that retinoic acid promotes macrophage transition from the M1 to M2 type by upregulating mitogen-activated protein kinase (MAPK) phosphatase 1 (MKP-1) expression and inhibiting P38, JNK and ERK phosphorylation in lipopolysaccharide-stimulated RAW264.7 cells. Notably, the therapeutic effects of retinoic acid were inhibited by MKP-1 knockdown. Retinoic acid exerts a significant therapeutic effect on adjuvant arthritis in mice by regulating macrophage polarization through the MKP-1/MAPK pathway, and play an important role in the treatment of rheumatic diseases.

Anti-inflammatory diterpenoids from the brown alga Dictyota coriacea.

A new xenicane diterpene named 4α-acetoxyisodictyohemiacetal (1) was isolated from the brown alga Dictyota coriacea, along with 11 known diterpenoids. The structure of 1 was established by spectroscopic analyses, and its absolute configuration was determined by comparing the experimental and theoretical electronic circular dichroism (ECD) spectra. Two dictyodiacetal diastereomers (5 and 6) were isolated and the full NMR assignments were performed. The anti-inflammatory activities of the isolated compounds were evaluated using the lipopolysaccharide-stimulated mouse macrophage cell line, RAW264. The hemiacetal-containing xenicanes and dictyol-type diterpene inhibited not only the production of nitric oxide, but also the expression of inducible nitric oxide synthase, interleukin-6, and cyclooxygenase-2 mRNA in RAW264 cells. This study demonstrated that diterpenes from Dictyota coriacea may be useful as natural anti-inflammatory agents.

Chemical analysis, antibacterial and anti-inflammatory effect of Achillea fragrantissima essential oil growing wild in Egypt

BackgroundAchillea fragrantissima (F. Asteraceae) is traditionally used to treat skin infections and inflammation. The present work intended to prepare essential oils (EOs) from A. fragrantissima aerial parts growing widely in Egypt and investigate its antibacterial activity against skin-related pathogens and in vitro cell-based anti-inflammatory activity.MethodsEOs of the fresh aerial parts were extracted by hydrodistillation (HD), microwave-assisted hydrodistillation (MAHD), and head-space (HS), while those of the dried ones were prepared by supercritical fluid (SF). The result EOs were analyzed using GC/MS. The antibacterial activity was evaluated alongside Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 25923, Streptococcus pyogenes ATCC 12344, Clostridium perfringens ATCC 13124 by agar diffusion, microwell dilution, and biofilm formation tests. The anti-inflammatory activity was evaluated by measuring tumor necrosis factor-alpha (TNF-α), interleukin 2 (IL-2), and 6 (IL-6) in lipopolysaccharides (LPS)- stimulated RAW 264.7 cells using ELISA assays in addition, expression of nitric oxide synthase (iNOS) was measured via western blot.ResultsThe SF method gave the highest EO yield (1.50 mL v/w). Oxygenated components constituted the highest percentage in the four methods, 84.14, 79.21, 73.29 and 33.57% in the HS, HD, MAHD, and SF, respectively. Moreover, variation in the amount of identified compounds was apparent; in HS EO α-thujone (29.37%), artemisia ketone (19.59%), and santolina alcohol (14.66%) are major components, while α-thujone (20.38%) and piperatone (12.09%) were significant in HD. Moreover, ( +)-spathulenol (12.22%) and piperatone (10.48%) were significant in MAHD, while piperatone (14.83%) and β-sitosterol (11.07%) were significant in SF EO. HD, MAHD, and SF EOs exhibited susceptibility against P. aeruginosa (IZ = 9–14 mm), E. coli (11–13 mm), and C. perfringens (IZ = 10–14 mm) in agar diffusion assay. MAHD EOs demonstrated potent growth inhibition (MICs = 0.25–2 mg/mL), followed by HD EOs (MICs = 13–52 mg/mL) to all tested microorganisms in well microdilution assay. Also, they exert MBC values equal to or higher than the MICs. Furthermore, SF EOs inhibited the biofilm formation of all tested microorganisms by 65.12—80.84%. Specifically, MAHD and HD EOs efficiently suppress the biofilm of S. pyogenes (77.87%) and P. aeruginosa (60. 29%), respectively. Ultimately, HD and SF EOs showed anti-inflammatory activity by suppressing the TNF-α, IL-2, and IL-6 release and iNOS expression in LPS-stimulated RAW 264.7 macrophages.ConclusionA. fragrantissima EO is rich in oxygenated volatile compounds with antibacterial and anti-inflammatory activities. It is encouraged as a bioactive agent for adjusting skin infections, though additional studies are essential for their safety in clinical settings.

Blood circulation effect of fermented citrus bioconversion product (FCBP) in EA.hy926 endothelial cells and high-fat diet-fed mouse model.

The escalating global burden of cardiovascular diseases, largely driven by unhealthy lifestyle choices and dietary patterns, has intensified the search for effective and safe interventions. With current treatments often marred by significant side effects, the exploration of natural compounds such as flavonoids presents a compelling alternative. This study investigated the effects of fermented citrus bioconversion product (FCBP), a fermented citrus bioflavonoid, on various markers of cardiovascular health in the context of a high-fat diet. In vivo, a high-fat diet-induced mouse model was used to assess the effects of FCBP on body weight, serum nitric oxide (NO) levels, activated partial thromboplastin time (aPTT), phosphatidylserine (PS) exposure on red blood cells, and the expression of inflammatory markers Intercellular Adhesion Molecule (ICAM)-1 and Vascular Cell Adhesion Molecule (VCAM)-1 in the thoracic aorta. In vitro, EA.hy926 endothelial cells were used to evaluate the compound's effects on cell viability, NO production, endothelial nitric oxide synthase (eNOS) expression, and cell adhesion molecule (CAM) levels to further understand the mechanisms behind the in vivo findings. In vivo, FCBP supplementation led to a dose-dependent reduction in weight gain, a significant decrease in serum NO levels at 10 mg/kg, and reduced ICAM-1 and VCAM-1 expressions in the thoracic aorta, indicating anti-inflammatory properties. PS exposure on red blood cells was also reduced, suggesting decreased procoagulant activity, while aPTT remained unchanged. In vitro, FCBP was non-cytotoxic to endothelial cells, showed a trend toward increased NO production and eNOS expression, and reduced the expression of ICAM-1 and VCAM-1, supporting its potential anti-inflammatory effects. FCBP demonstrates potential as a bioactive compound for managing cardiovascular health by reducing inflammation, mitigating weight gain, and influencing blood circulation-related parameters under high-fat diet conditions. Further studies, including diverse models and human trials, are warranted to elucidate its mechanisms and compare its efficacy with established cardiovascular therapeutics.

Network pharmacology combined with transcriptomics reveals that formononetin, a biologically component of Astragalus membranaceus (Fisch.) Bunge, inhibits the PI3K/AKT signaling pathway to improve chronic renal failure

Ethnopharmacological relevanceFormononetin (FMN), one of the main isoflavones isolated from Astragalus membranaceus (Fisch.) Bunge, has multiple pharmacological and renal-protective effects. Our previous study suggested FMN as a candidate compound for the treatment of chronic renal failure (CRF). However, the mechanism underlying the repressive effect of FMN on the development of CRF is still unknown. Aims of the studyTo investigate the protective effect of FMN on CRF using in vivo and in vitro models and elucidate the potential underlying mechanism. Materials and methodsAn in vivo model of adenine-induced CRF and an in vitro model of human proximal tubule epithelial cells (HK-2) stimulated with transforming growth factor (TGF)-β1 were used. Serum levels of renal function parameters and inflammatory cytokines were evaluated. Histological analysis was performed to determine the extent of renal injury and fibrosis. Network pharmacology and mRNA sequencing were used to explore the potential mechanism. PPI analysis and molecular docking were used to identify key targets. Polymerase chain reaction and western blotting were used to determine the mechanism underlying the effect of FMN on CRF. ResultsFMN decreased the levels of renal function biochemical markers, including serum creatinine, blood urea nitrogen, and 24 h urine protein content. Treatment with FMN improved renal tubule injury and extracellular matrix (ECM) components, including collagens I and III. In addition, FMN significantly inhibited epithelial-mesenchymal transition (EMT); decreased the expression of fibronectin, N-cadherin, vimentin, α-SMA, and TGF-β1; and restored the expression of E-cadherin. The effect of FMN on renal interstitial fibrosis contributed to decreasing the expression of PI3K, p-Akt, and interleukin (IL) 4, restoring the expression of nitric oxide synthase 3 (NOS3), and reducing the release of inflammatory cytokines (IL-1β, IL-6, and tumor necrosis factor-alpha), both in vivo and in vitro. FMN treatment improved renal function and deposition of ECM components, reduced protein levels of EMT markers in rat kidneys and HK-2 cells, decreased the release of inflammatory cytokines, and inhibited the PI3K/Akt signaling pathway. ConclusionsFMN treatment significantly reduced the release of inflammatory cytokines and inhibited the effects of the PI3K/Akt signaling pathway on the key targets IL-4 and NOS3. Our results suggest FMN therapy as a novel therapeutic strategy for treating CRF.

The Role of Hydrogen Sulfide in iNOS and APP Localization and Expression in Neurons and Glial Cells Under Traumatic Effects: An Experimental Study with Bioinformatics Analysis and Biomodeling.

Hydrogen sulfide (H2S) donors are emerging as promising candidates for neuroprotective agents. However, H2S-dependent neuroprotective mechanisms are not yet fully understood. We have demonstrated that an H2S donor (sodium sulfide, Na2S) reduces the expression of inducible NO synthase (iNOS) and amyloid-beta precursor protein (APP) in damaged neural tissue at 24 h and 7 days following traumatic brain injury (TBI). The application of aminooxyacetic acid (AOAA), an inhibitor of cystathionine β-synthase (CBS), produced the opposite effect. Seven days after TBI, iNOS expression was observed not only in the cytoplasm but also in some neuronal nuclei, while APP was exclusively localized in the cytoplasm and axons of damaged neurons. It was also shown that iNOS and APP were present in the cytoplasm of mechanoreceptor neurons (MRNs) in the crayfish, in axons, as well as in certain glial cells 8 h after axotomy. Na2S and AOAA had opposing effects on axotomized MRNs and ganglia in the ventral nerve cord (VNC). Multiple sequence alignments revealed a high degree of identity among iNOS and APP amino acid residues in various vertebrate and invertebrate species. In the final stage of this study, biomodeling identified unique binding sites for H2S, hydrosulfide anion (HS-), and thiosulfate (S2O32-) with iNOS and APP.

Chitosan oligosaccharides: A potential therapeutic agent for inhibiting foam cell formation in atherosclerosis

Foam cell formation is a key hallmark in atherosclerosis and associated cardiovascular diseases (CVDs). The potential anti-atherosclerotic potential of chitosan oligosaccharides (COS) was investigated using oxLDL-treated RAW264.7 murine cells. COS treatment led to a significant inhibition of lipid accumulation, as demonstrated by Oil Red O staining, and reduced levels of total cholesterol, free cholesterol, cholesterol esters, and triglycerides in.oxLDL-treated RAW264.7 cells. COS blocked cholesterol influx through down-regulating class A1 scavenger receptors (SR-A1) and cluster of differentiation 36 (CD36) expression and stimulated cholesterol efflux through up-regulating ABC transporters ABCA-1 and ABCG-1 expressions. Additionally, COS treatment stimulated nuclear signaling pathways involving peroxisome proliferator-activated receptor-γ (PPAR-γ) and liver X receptor α (LXR-α), and also led to the phosphorylation of AMP-activated protein kinase (AMPK). COS further demonstrated anti-inflammatory effects by inhibiting the production of pro-inflammatory cytokines and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in oxLDL-treated RAW264.7 cells, through suppression of NF-κB signaling. Furthermore, COS alleviated oxidative stress induced by oxLDL by activating Nrf2 signaling and enhancing the expression of antioxidant genes, including heme oxygenase-1 (HO-1), superoxide dismutase (SOD), glutathione peroxidase (Gpx), and catalase (CAT). In conclusion, COS can be beneficial in preventing atherosclerosis and related diseases.

The green formulation of silver nanoparticles for the anticancer and lupus nephritis treatment applications and reducing the inflammatory cytokines in the rat periodontal model

In this study, a novel bio-inspired synthesis for the preparation of Ag NPs by Calendula persica flower extract has been researched. Also, the effects of the recent composite on lupus nephritis by following the TGF-β1 signaling pathway in mice and gingival amounts of IL1-β and TNF-α in the animal periodontal model were determined. To assess the crystal nature, morphology and size of the prepared nanoparticles, X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet–visible (UV–Vis) and field emission-scanning electron microscopy (FE-SEM) analyses were applied in this study. The prepared Ag NPs was employed for its effectiveness against colon cancer cell line (C26). The bio-synthesized Ag NPs had also cytotoxic property versus colon cancer based on MTT protocol. Collectively, the Ag NPs fabricated by biological way has potential applications in inflammatory treatment. In lupus nephritis section, indexes in animal tissues and serum were identified using specific kits, while pathological alterations in the mice kidney were examined through H&E staining. Additionally, qPCR was employed to determine the expression related to TGF-β 1 in kidney, thereby providing further insight into the silver nanoparticles mechanism. The findings indicated that silver nanoparticles reduced the mRNA expression levels of TGF-β 1 and NF-κB in the kidneys, while simultaneously increasing the Mn-SOD and IκB-α expression. Histological examination of H&E-stained sections revealed that silver nanoparticles mitigated the morphological abnormalities of the glomeruli and the inflammatory infiltration associated with nephritis. Silver nanoparticles demonstrated an inhibitory effect on the dsDNA positive rate in animal suffering from nephritis. Silver nanoparticles were found to reduce the increase in urinary protein and the pro-inflammatory cytokines concentrations in both the kidney and serum. In the periodontal model study, 0-3 ligatures were applied to induce the inflammatory periodontitis in right mandibular first molar neck in rats. The levels of inflammatory cytokines (IL1-β, CINC-1, IL-10 and TNF-α) were determined by common immunological test, ELISA. The findings revealed that Ag NPs administration could decease the IL1-β and TNF-α production in the rat periodontal model gum tissue. In addition, the outcome of this research indicated that IL1-β and TNF-α levels raised in the rat periodontal model gum tissue compared to control group. Ag NPs increased the levels of superoxide dismutase, catalase, and plasma bone alkaline phosphatase and reduced the IL1-β, TNF-α, inducible nitric oxide synthase and RANK genes mRNA expression. The results indicate that pre/post-treatment with Ag NPs because of its direct activity on pro-inflammatory cytokines inhibition improved the inflammatory symptoms in the periodontitis and lupus nephritis animals.

Dapagliflozin mitigates cellular stress and inflammation through PI3K/AKT pathway modulation in cardiomyocytes, aortic endothelial cells, and stem cell-derived β cells

Dapagliflozin (DAPA), a sodium-glucose cotransporter 2 (SGLT2) inhibitor, is well-recognized for its therapeutic benefits in type 2 diabetes (T2D) and cardiovascular diseases. In this comprehensive in vitro study, we investigated DAPA’s effects on cardiomyocytes, aortic endothelial cells (AECs), and stem cell-derived beta cells (SC-β), focusing on its impact on hypertrophy, inflammation, and cellular stress. Our results demonstrate that DAPA effectively attenuates isoproterenol (ISO)-induced hypertrophy in cardiomyocytes, reducing cell size and improving cellular structure. Mechanistically, DAPA mitigates reactive oxygen species (ROS) production and inflammation by activating the AKT pathway, which influences downstream markers of fibrosis, hypertrophy, and inflammation. Additionally, DAPA’s modulation of SGLT2, the Na+/H + exchanger 1 (NHE1), and glucose transporter (GLUT 1) type 1 highlights its critical role in maintaining cellular ion balance and glucose metabolism, providing insights into its cardioprotective mechanisms. In aortic endothelial cells (AECs), DAPA exhibited notable anti-inflammatory properties by restoring AKT and phosphoinositide 3-kinase (PI3K) expression, enhancing mitogen-activated protein kinase (MAPK) activation, and downregulating inflammatory cytokines at both the gene and protein levels. Furthermore, DAPA alleviated tumor necrosis factor (TNFα)-induced inflammation and stress responses while enhancing endothelial nitric oxide synthase (eNOS) expression, suggesting its potential to preserve vascular function and improve endothelial health. Investigating SC-β cells, we found that DAPA enhances insulin functionality without altering cell identity, indicating potential benefits for diabetes management. DAPA also upregulated MAFA, PI3K, and NRF2 expression, positively influencing β-cell function and stress response. Additionally, it attenuated NLRP3 activation in inflammation and reduced NHE1 and glucose-regulated protein GRP78 expression, offering novel insights into its anti-inflammatory and stress-modulating effects. Overall, our findings elucidate the multifaceted therapeutic potential of DAPA across various cellular models, emphasizing its role in mitigating hypertrophy, inflammation, and cellular stress through the activation of the AKT pathway and other signaling cascades. These mechanisms may not only contribute to enhanced cardiac and endothelial function but also underscore DAPA’s potential to address metabolic dysregulation in T2D.Graphical abstract

Sirt5 as a mediator of endothelial and vascular dysfunction: potential therapeutic target in aging-related vascular diseases

Abstract Background Aging is one of the most dominant cardiovascular (CV) risk factors. Sirt5 belongs to the lifespan-regulating sirtuin superfamily as a protein deacylase. However, its regulatory effects on vascular function and aging are yet unclear. Purpose We therefore aimed to investigate the roles of Sirt5 on endothelial and vascular function during aging, decipher the underlying mechanisms, and to explore its potential as a therapeutic target through in vivo and in vitro studies. Methods Aortic expression of Sirt5 were studied in C5BL/6 wild type (WT) mice during aging, followed by vascular functional and structural assessment in WT mice and Sirt5-overexpressing mice (Sirt5/Tg) using the established myograph system and histological staining respectively. Furthermore, the regulatory role of Sirt5 on endothelial function was investigated in senescent primary human aortic endothelial cells (HAECs, passages 13-15) by studying its interference with endothelial nitric oxide synthase (eNOS) expression and activity in knock-down experiments using siRNA. The therapeutic potential of Sirt5 inhibition was explored at the tissue level in myograph experiments. Results Aged WT mice had increased level of Sirt5 in aorta compared to the young ones. Overexpression of Sirt5 in vivo led to significantly reduced aortic endothelial-dependent relaxation and displayed thicker collagen deposition in the adventitia compared to aged WT controls. The reduction of vascular relaxing response in Sirt5/Tg mice was prevented by an addition of eNOS inhibitor (L-name), indicating that Sirt5 regulated vascular function through the eNOS pathway. In senescent HAECs, knock-down of Sirt5 markedly induced total eNOS expression and increased its activity (phospho-eNOS Ser1177), further confirming the regulatory role of Sirt5 on eNOS pathway. In line with the above, aorta from aged WT mice displayed improved endothelial function after pharmacological inhibition of Sirt5. Conclusion Vascular Sirt5 expression increases with age and contributes to aging-related endothelial dysfunction by downregulating the eNOS pathway. Thus, Sirt5 inhibition may represent a novel therapeutic approach to maintain vascular function during aging. Ongoing studies will investigate Sirt5 silencing in-vivo using RNA interference for its therapeutic potential to prevent aging-related vascular dysfunction.

UHT Cow's Milk Supplementation Affects Cell Niches and Functions of the Gut-Brain Axis in BALB/c Mice.

Cow's milk is a bioactive cocktail with essential nutritional factors that is widely consumed during early childhood development. However, it has been associated with allergic responses and immune cell activation. Here, we investigate whether cow's milk consumption regulates gut-brain axis functions and affects patterns of behaviors in BALB/c mice, previously described by present low sociability, significant stereotypes, and restricted interest features. The major objectives consist of to investigate cow's milk supplementation as possible triggers interfering with cellular niches of the gut-brain axis and behavioral patterns. Male BALB/c at 6 weeks were randomly divided into two groups, one supplemented with cow's milk processed at ultra-high temperature (UHT) and another group receiving water (controls) three times per day (200 μL per dose) for one week. Milk consumption disturbed histological compartments of the small intestine, including niches of KI67+-proliferating cells and CD138+ Ig-secreting plasma cells. In the liver, milk intake was associated with pro-inflammatory responses, oxidative stress, and atypical glycogen distribution. Milk-supplemented mice showed significant increase in granulocytes (CD11b+SSChigh cells) and CD4+ T cells in the blood. These mice also had neuroinflammatory signals, including an enhanced number of cortical Iba-1+ microglial cells in the brain and significant cerebellar expression of nitric oxide synthase 2 by Purkinje cells. These phenotypes and tissue disorders in milk-supplemented mice were associated with atypical behaviors, including low sociability, high restricted interest, and severe stereotypies. Moreover, synaptic niches were also disturbed after milk consumption, and Shank-3+ and Drebrin+ post-synaptic cells were significantly reduced in the brain of these mice. Together, these data suggest that milk consumption interfered with the gut-brain axis in BALB/c mice and increased atypical behaviors, at least in part, linked to synapse dysfunctions, neuroinflammation, and oxidative stress regulation.

Identification of nitric oxide-mediated necroptosis as the predominant death route in Parkinson’s disease

Parkinson's disease (PD) involves multiple forms of neuronal cell death, but the dominant pathway involved in disease progression remains unclear. This study employed RNA sequencing (RNA-seq) of brain tissue to explore gene expression patterns across different stages of PD. Using the Scaden deep learning algorithm, we predicted neurocyte subtypes and modelled dynamic interactions for five classic cell death pathways to identify the predominant routes of neuronal death during PD progression. Our cell type-specific analysis revealed an increasing shift towards necroptosis, which was strongly correlated with nitric oxide synthase (NOS) expression across most neuronal subtypes. In vitro experiments confirmed that nitric oxide (NO) is a key mediator of necroptosis, leading to nuclear shrinkage and decreased mitochondrial membrane potential via phosphorylation of the PIP1/PIP3/MLKL signalling cascade. Importantly, specific necroptosis inhibitors significantly mitigated neuronal damage in both in vitro and in vivo PD models. Further analysis revealed that NO-mediated necroptosis is prevalent in early-onset Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS) and across multiple brain regions but not in brain tumours. Our findings suggest that NO-mediated necroptosis is a critical pathway in PD and other neurodegenerative disorders, providing potential targets for therapeutic intervention.

Ilex asprella-derived polysaccharide activates macrophage via TLR4-mediated NF-κB and MAPK signaling pathways

Ilex asprella, a valued herb in China, is recognized for its medicinal and dietary benefits, yet its active components and mechanisms of action have been largely unknown. This study focused on the polysaccharide extracted from Ilex asprella (IAP) and to investigate its structural characteristics and immunomodulatory effects. The results indicated IAP had a molecular weight of 3324 Da and was mainly composed of arabinose, galactose, glucose, and mannose. In vitro study showed 10, 50, and 100 μg/mL of IAP significantly increased the mRNA expression of inducible nitric-oxide synthase, cyclooxygenase-2, reactive oxygen, and cytokines in RAW264.7 macrophages. According to the results, IAP also facilitated the nucleus translocation of NF-κB p65 and activated the phosphorylation of p38, JNK, and ERK, revealing IAP activated RAW264.7 cells via NF-κB and MAPK signaling pathways. Furthermore, the results of membranes receptor inhibitor administration suggested toll-like receptor 4 might be the action target of IAP.

Investigation of the chemical composition and biological activities of Eremurus spectabilis M. Bieb through antioxidant, enzyme inhibition, COX-2 and iNOS assessment.

Eremurus spectabilis is widespread and used primarily for medicinal and culinary purposes. This study aimed to evaluate the chemical composition, antiradical and antioxidant activities, enzyme inhibitory activities, and anti-inflammatory properties of various extracts from the aerial parts of E. spectabilis. Various assays were used to investigate the antioxidant and enzyme inhibitory properties. The chemical composition of the tested extracts was analyzed using High-Performance Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry (HPLC-ESI-MS/MS). Additionally, the extracts were tested on isolated mouse colon tissue challenged with E. coli lipopolysaccharide (LPS) to replicate the inflammation and oxidative stress burden characteristic of inflammatory bowel diseases. In the chemical composition, vanillic, ferulic, 4-hydroxybenzoic acids were the prominent compounds. The greatest antioxidant activity was observed in the methanol and water extracts from the aerial parts. Enzyme inhibition tests showed that the ethyl acetate extract had the highest anti-acetylcholinesterase activity. The gene expression of pro-inflammatory cyclooxygenase-2 (COX-2) and pro-oxidant inducible nitric oxide synthase (iNOS) biomarkers were assayed. Among the extracts, the methanol extract was the most effective in blunting LPS-induced gene expression of COX-2. E. spectabilis may serve as a valuable source of phytochemicals for combating oxidative stress and inflammation-driven diseases, with a particular emphasis on colon inflammatory condition.

Ultrasound-assisted low-temperature extraction of polysaccharides from Lavandula angustifolia Mill.: optimization, structure characterization, and anti-inflammatory activity

Lavandula angustifolia Mill. is a traditional Chinese medicinal herb with high economic and pharmacological value. In this study, we optimized the conditions for low-temperature ultrasound-assisted extraction of L. angustifolia Mill. polysaccharides using response surface methodology (RSM), and two homopolysaccharides LAPW1 (33.6 kDa) and LAPS1 (95.9 kDa) were obtained after isolation and purification by DEAE-650 M and Superdex™ 200 chromatography. The primary structure of LAPS1 was determined using “partial acid hydrolysis, methylation, two-dimensional (2D NMR) spectroscopy” as the core method. The results revealed that LAPS1 is a heteropolysaccharide whose main chain consists of [-1)-β-Galp-(6→1)-α-Araf-(5→]3-1-α-Araf-(3→1)-α-Araf-(5→[1)-β-Galp-(6→1)-α-Araf-(5→]3-1-α-Araf-(5→1)-α-Araf-(5→[-1)-β-Galp-(6→1)-α-Araf-(5→]3. In vitro experiments revealed that LAPW1 and LAPS1 significantly reduced the production of the inflammatory cytokines Interleukin-1β (IL-1β), Interleukin-6 (IL-6), and Tumor Necrosis Factor (TNF), as well as the expression of Nitric Oxide Synthase 2 (NOS2) and release of nitric oxide (.NO) free radical in the inflammatory model established by lipopolysaccharide (LPS) stimulated RAW264.7. Besides, the zebrafish inflammatory model, stimulated by CuSO4, was employed to assess the impact of polysaccharides on neutrophil migration, indicating a notable decrease in zebrafish neutrophils and confirming their potential anti-inflammatory activity. These results indicate that polysaccharides from L. angustifolia Mill. be used in the development of functional foods and pharmaceutical products.

Limosilactobacillus reuteri HY7503 and Its Cellular Proteins Alleviate Endothelial Dysfunction by Increasing Nitric Oxide Production and Regulating Cell Adhesion Molecule Levels.

Endothelial dysfunction, which is marked by a reduction in nitric oxide (NO) production or an imbalance in relaxing and contracting factor levels, exacerbates atherosclerosis by promoting the production of cell adhesion molecules and cytokines. This study aimed to investigate the effects of Limosilactobacillus reuteri HY7503, a novel probiotic isolated from raw milk, on endothelial dysfunction. Five lactic acid bacterial strains were screened for their antioxidant, anti-inflammatory, and endothelium-protective properties; L. reuteri HY7503 had the most potent effect. In a mouse model of angiotensin II-induced endothelial dysfunction, L. reuteri HY7503 reduced vascular thickening (19.78%), increased serum NO levels (226.70%), upregulated endothelial NO synthase (eNOS) expression in the aortic tissue, and decreased levels of cell adhesion molecules (intercellular adhesion molecule-1 [ICAM-1] and vascular cell adhesion molecule-1 [VCAM-1]) and serum cytokines (tumor necrosis factor-alpha [TNF-α] and interleukin-6 [IL-6]). In TNF-α-treated human umbilical vein endothelial cells (HUVECs), L. reuteri HY7503 enhanced NO production and reduced cell adhesion molecule levels. In HUVECs, surface-layer proteins (SLPs) were more effective than extracellular vesicles (exosomes) in increasing NO production and decreasing cell adhesion molecule levels. These findings suggested that L. reuteri HY7503 may serve as a functional probiotic that alleviates endothelial dysfunction.