Cyclooxygenase-2 Expression Research Articles

Nephroprotective Activity of Angelica keiskei (Miq). Koidz. on Cisplatin-Induced Rats: Reducing Serum Creatinine, Urea Nitrogen, KIM-1, and Suppressing NF-kappaB p65 and COX-2.

The sap of Angelica keiskei (Miq). Koidz. has been reported for its abundance of chalcone contents. Chalcones have been known for their effective nephroprotective activity toward cisplatin-induced renal cells and mice. To investigate the effect of A. keiskei sap extract (ASEE) on kidney function parameters (serum creatinine, urea nitrogen, and kidney injury molecule-1) and the expression of NF-kappaB p65 and COX-2 in cisplatin-induced Wistar rats. In vivo nephroprotective activity of ASEE at 1000 and 1500 mg/kg BW/day doses for 10 days on cisplatin (5 mg/kg BW) induced nephrotoxicity was evaluated on Wistar rats. Quercetin 20 mg/kg BW/day was used as the control drug. Cisplatin inducement was given on day 7. The BW was measured every day. On day 11, the rats were euthanized, and their blood was taken intracardially for creatinine and urea nitrogen analysis. Histopathological analysis was carried out on the right kidney, and KIM-1 levels in the left kidney were measured. The Western blot technique evaluated the NF-kappaB p65 and COX-2 expression in the kidney. All data obtained were compared to the cisplatin group (negative control). The total flavonoids and chalcones in ASEE were also determined. Pretreatment with ASEE reduces the BW of Wistar rats, and significantly reduces creatinine and KIM-1 levels, but does not significantly reduce the levels of urea nitrogen, the expression of NF-kappaB p65, and COX-2 in the kidney of cisplatin-induced Wistar rats. The total flavonoid content in ASEE is 8.755 g QE/100 g extract and the total chalcone content is 5.532 g IBCE/100 g extract. The sap of Angelica keiskei (Miq). Koidz. reveal the potential to protect the kidneys against cisplatin-induced toxicity. The nephroprotective activity may be attributed to the antioxidant and anti-inflammatory properties of the flavonoids and the chalcones contained in the sap of Angelica keiskei (Miq). Koidz.

Protective effects of nordalbergin against LPS-induced endotoxemia through inhibiting MAPK/NF-κB signaling pathway, NLRP3 inflammasome activation, and ROS production.

Nordalbergin is a coumarin extracted from Dalbergia sissoo DC. To date, the biological effects of nordalbergin have not been well investigated. To investigate the anti-inflammatory responses and the anti-oxidant abilities of nordalbergin using lipopolysaccharide (LPS)-activated macrophages and LPS-induced sepsis mouse model. Production of nitrite oxide (NO), prostaglandin E2 (PGE2), pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β), reactive oxygen species (ROS), tissue damage and serum inflammatory markers, and the activation of the NLRP3 inflammasome were examined. Our results indicated that nordalbergin reduced the production of NO and pro-inflammatory cytokines in vitro and ex vivo. Nordalbergin also suppressed iNOS and cyclooxygenase-2 expressions, decreased NF-κB activity, and attenuated MAPKs signaling pathway activation by decreasing JNK and p38 phosphorylation by LPS-activated J774A.1 macrophages. Notably, nordalbergin diminished NLRP3 inflammasome activation via repressing the maturation of IL-1β and caspase-1 and suppressing ROS production by LPS/ATP- and LPS/nigericin-activated J774A.1 macrophages. Furthermore, nordalbergin exhibited protective effects against the infiltration of inflammatory cells and also inhibited the levels of organ damage markers (AST, ALT, BUN) by LPS-challenged mice. Nordalbergin possesses anti-inflammatory effects in macrophage-mediated innate immune responses, alleviates ROS production, decreases NLRP3 activation, and exhibits protective effects against LPS-induced tissue damage in mice.

Qingfei Zhisou oral liquid alleviates fever-induced inflammation by regulating arachidonic acid and lysophospholipids metabolism and inhibiting hypothalamus transient receptor potential ion channels expression.

To explore how Qingfei Zhisou oral liquid (, QFZS) adjusts body temperature bias and the interaction of inflammatory factors levels and metabolomic differences. Dry yeast was subcutaneously injected at 10 mL/kg to establish the pyrexia model. We randomly divided 60 Sprague-Dawley rats into five groups: control, model, positive, low dose of QFZS and high dose of QFZS. Inflammatory proteins were evaluated by Western blotting and immunohistochemistry. For the examination of the endogenous metabolites, enzyme linked immunosorbent assay and ultra-high-performance liquid chromatography high-resolution mass spectrometry were employed. QFZS significantly reduced rats' body temperature within 6 h after dry yeast injection and reduced the secretion of the arginine vasopressin, cyclic adenosine monophosphate, prostaglandin E-2, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β in serum. Meanwhile, we identified 41 metabolites between the model and QFZS groups, including arachidonic acid and lysophospholipids. QFZS restored normal arachidonic acid levels. Based on the differential metabolite enrichment analysis, QFZS's anti-inflammatory and anti-pyrexia effects might be related to the inflammatory pathway regulated by transient receptor potential. Additionally, QFZS treatment reduced transient receptor potential melastatin 2 ion channel expression and affected TNF-α, heat shock protein 70, and cyclooxygenase-2 expression in the hypothalamus. QFZS exerts its regulatory effects on fever by regulating the metabolism of lysophospholipids and arachidonic acid and the regulation of inflammation via transient receptor potential ion channels channels.

Almond polysaccharides inhibit DSS-induced inflammatory response in ulcerative colitis mice through NF-κB pathway

Ulcerative colitis (UC), a type of inflammatory bowel disease (IBD), is a chronic recurrent inflammatory disease of the colon. Our previous findings demonstrated that almond polysaccharide (AP-1) exhibits significant anti-inflammatory activity in vitro. Therefore, this study aimed to explore the ameliorative effect of AP-1 on dextrose sodium sulfate (DSS)-induced UC mice and to elucidate its possible mechanism of action. By observing changes in body weight, fecal viscosity, stool blood, disease activity index, and colon length, we found that AP-1 attenuated inflammation. It inhibited TNF-α, IL-1β, and IL-6 while boosting anti-inflammatory IL-10 levels. Histomorphologically, AP-1 protected against DSS-induced colonic tissue damage by reducing inflammatory cell infiltration and mucosal injury. It also lowered myeloperoxidase (MPO) and NO while increasing total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) in colonic tissues. Moreover, using the Western blot technique, AP-1 was shown to inhibit the phosphorylation of p65 and IκB-α proteins in the NF-κB/iNOS/COX2 signaling pathway and down-regulate the expression of inflammation-associated proteins COX2 and iNOS, thus slowing down and ameliorating inflammatory processes. Therefore, the safe and effective beneficial effects of AP-1 make it a promising therapeutic strategy for relieving IBD, especially UC.

Novel injectable polypeptide nanoparticle encapsulated siRNA targeting TGF-β1 and COX-2 for localized fat reduction I: Preclinical invitro and animal models.

Obesity and localized fat accumulation continue to drive the demand for minimally invasive body contouring technologies including injectable compounds for local fat reduction. siRNA offers a potential for an injectable to specifically target and silence genes involved in adipogenesis with minimal inflammatory side effects. This study evaluates the efficacy of STP705, an injectable containing siRNA encapsulated within histidine-lysine polypeptide (HKP) nanoparticles targeting transforming growth factor β1 (TGF-β1) and cyclooxygenase-2 (COX-2), crucial mediators in adipocyte differentiation and fat retention, using invitro, porcine, and murine models. In vitro experiments on mouse preadipocytes and invivo trials using Diet Induced Obese (DIO) mice and Yucatan minipigs were conducted to assess the gene silencing efficiency, tissue localization, pharmacodynamics, and safety profile of STP705. STP705 effectively reduced the expression of TGF-β1 and COX-2, with a notable decrease in adipocyte volume and lipid content without adverse systemic effects. In DIO mice, the HKP-siRNA complex demonstrated precise localization to injected adipose tissue, maintaining significant gene silencing, and detectable levels of siRNA for up to 14 days post-administration. Similar results in minipigs showed a significant reduction in subcutaneous adipose tissue thickness. The results of these studies support the use of targeted siRNA therapy specifically targeting TGF-β1 and COX-2, for localized fat reduction, offering a potential minimally invasive alternative to current fat reduction methods.

P2X4 receptor mediates macrophage infiltration leading to endometriotic cyst epithelium proliferation and hyperalgesia in mouse model

To evaluate the effects of a P2X4 receptor (P2X4R)-specific antagonist on murine endometriotic-like lesions and human endometriotic stromal cells. Experimental study using an in vivo mouse endometriosis model and in vitro primary culture of human endometriotic stromal cells. NC-2600, an antagonist of the P2X4 ionotropic ATP receptor (P2X4R), was orally administered to the mice and cells. Gene expression analyses for cytokines were conducted in the endometriotic-like cysts and vaginal portion of mice, and immunohistochemistry was performed to evaluate the proliferative activity and localization of macrophages in addition to cytokine expression. The sensation of murine vaginal pain was evaluated using visceromotor responses. The study was performed in academic and hospital research laboratories. NC-2600 reduced the proliferation of the cyst epithelium and vaginal pain sensation. In both cysts and vaginas, P2X4R is mainly expressed in macrophages, and NC-2600 reduces the number of tissue macrophages and reverses the elevated expression of InterleukinL-33 and cyclooxygenase-2 in animals with endometriosis. These results indicate unknown pathophysiological roles of P2X4R expressed in local macrophages at the injury site of endometriosis and in the vagina, suggesting the potential therapeutic effects of orally administered P2X4R inhibitors for alleviating the symptoms of endometriosis.

Aspirin reduces Ponatinib-induced cardiovascular toxic phenotypes and death in zebrafish

BackgroundPonatinib (Iclusig) is an oral tyrosine kinase BCR-ABL inhibitor for treating patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and chronic myeloid leukemia (CML) who are resistant to the therapies with other tyrosine kinase inhibitors. However, adverse cardiovascular events caused by Ponatinib are a serious issue that affects patients' survival rates. Thus, it is necessary to search for candidate drugs to reduce the cardiovascular toxicity of Ponatinib. PurposeTo investigate the effects of Aspirin on Ponatinib-induced cardiovascular toxicity in zebrafish. MethodsAB strain of wild type zebrafish (Danio rerio), Tg (cmlc2: GFP) transgenic zebrafish, and Tg (gata1: dsRed) transgenic zebrafish were used as in vivo models to assess survival, blood flow, cardiac morphology, and function. Thrombus formation was detected using O-dianisidine staining. The transcriptome of zebrafish larvae treated with Ponatinib was assessed using RNA sequencing. ResultsPonatinib not only reduced survival rate but also caused cardiovascular toxic events such as pericardial edema, abnormal heart structure, low heart rate, and thrombosis. In addition, whole-body transcriptome analysis showed that Ponatinib up-regulated the expression of cyclooxygenase-1 (COX-1). Compared with other antithrombotic drugs, a COX-1 inhibitor Aspirin more effectively reduced ponatinib-induced cardiovascular toxicity events and improved the survival rate of zebrafish larvae. ConclusionOur findings suggest that Aspirin exhibits the potential to reduce Ponatinib-induced cardiovascular toxicity.

Effect of Siegesbeckia glabrescens Extract on Foam Cell Formation in THP-1 Macrophages.

The accumulation of cholesterol-bearing macrophage foam cells in the initial stages of atherosclerosis serves as a characteristic feature of atherosclerotic lesions. The inhibitory effect of Siegesbeckia glabrescens, a species of flowering plant in the Asteraceae family, on foam cell formation in THP-1 macrophages has not yet been elucidated. In this study, we explored the effect of S. glabrescens ethanol extract (SGEE) and hot water extract (SGWE) on foam cell formation via co-treatment with oxidized low density lipoprotein (ox-LDL) and lipopolysaccharide (LPS), mimicking the occurrence of atherosclerosis in vitro, and studied the regulation of its underlying mechanisms. THP-1 cells differentiated by PMA (1 μM) for 48 h were subsequently treated with/without SGWE and SGEE for 48 h. THP-1 macrophages were treated with ox-LDL (20 μg/mL) and LPS (500 ng/mL) for 24 h. Treatment with ox-LDL and LPS for 24 h enhanced the lipid accumulation in foam cells compared to in untreated cells, as determined by oil red O staining. In contrast, SGWE and SGEE treatment inhibited lipid accumulation in foam cells. Both extracts significantly upregulated ABCA1, LXRα, and PPARγ expression in ox-LDL- and LPS-treated cells (P<0.05). Moreover, both SGWE and SGEE decreased LOX-1, CD36, and SR-A1 expression. The co-treatment of ox-LDL and LPS increased NF-κB, COX-2, and pro-inflammatory activation and expression compared with untreated cells. However, this increase suppressed NF-κB, COX-2, and pro-inflammatory expression by SGWE and SGEE. The results indicated that both extracts can partially inhibit foam cell formation and contribute to protective effects by suppressing cholesterol accumulation during the onset of atherosclerosis.

Protective Responses of Green Yuja Peel Extracts to Lipopolysaccharide-Induced Inflammation and Reactive Oxygen Species Production in RAW264.7 Cells.

This study assessed the anti-inflammatory and antioxidant effects of green yuja peel hot water extract (GYW) and ethanol extract (GYE) on lipopolysaccharide (LPS)-stimulated RAW264.7 cells. GYW and GYE (50, 100, and 200 μg/mL) significantly reduced the LPS-induced production of nitric oxide (NO), interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and reactive oxygen species in a concentration-dependent manner, without cytotoxicity. Compared with control cells, GYW and GYE significantly downregulated the protein levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) and the gene expression of iNOS, COX-2, TNF-α, and IL-6. Conversely, they upregulated the gene expression of IL-10. Moreover, GYW and GYE significantly suppressed NF-κB p65 and IκB-α phosphorylation and increased the protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target heme oxygenase-1 (HO-1) compared with control cells. These results suggest that GYW and GYE exhibit anti-inflammatory and antioxidative properties by downregulating the NF-κB signaling pathway and upregulating the Nrf2/HO-1 system in LPS-activated macrophages.

Silibinin Suppresses Inflammatory Responses Induced by Exposure to Asian Sand Dust.

Asian sand dust (ASD), generated from the deserts of China and Mongolia, affects Korea and Japan during spring and autumn, causing harmful effects on various bio-organs, including the respiratory system, due to its irritants such as fine dust, chemicals, and toxic materials. Here, we investigated the therapeutic effects of silibinin against ASD-induced airway inflammation using mouse macrophage-like cell line RAW264.7 and a murine model. ASD was intranasally administered to mice three times a week and silibinin was administered for 6 days by oral gavage. In ASD-stimulated RAW264.7 cells, silibinin treatment decreased tumor necrosis factor-α production and reduced the expression of p-p65NF-κB, p-p38, and cyclooxygenase (COX)-2, while increasing heme oxygenase (HO)-1 expression. In ASD-exposed mice, silibinin administration reduced inflammatory cell count and cytokines in bronchoalveolar lavage fluid and decreased inflammatory cell infiltration in lung tissue. Additionally, silibinin lowered oxidative stress, as evidenced by decreased 8-hydroxy-2'-deoxyguanosin (8-OHdG) expression and increased HO-1 expression. The expression of inflammatory-related proteins, including p-p65NF-κB, COX-2, and p-p38, was markedly reduced by silibinin administration. Overall, silibinin treatment reduced the expression of p-p65NF-κB, COX-2, and p-p38 in response to ASD exposure, while increasing HO-1 expression both in vitro and in vivo. These findings suggest that silibinin mitigates pulmonary inflammation caused by ASD exposure by reducing inflammatory signaling and oxidative stress, indicating its potential as a therapeutic agent for ASD-induced pulmonary inflammation.

Inhibition of Colon Cancer Xenograft Growth by Celecoxib Analog OSU-03013 Through Wnt/β-Catenin Pathway Modulation

OSU-03013 is a Celecoxib analog that dose not inhibit COX-2 expression. OSU-03013 effectively mimics the anti-tumor effects of Celecoxib, however, its exact mechanism in colon cancer (CC) is unknown. SW480 cells were injected subcutaneously into the axilla of nude mice until the volume of the transplanted tumor reached 80 mm3. SW480 cells were inoculated into the tail vein of nude mice to establish a liver metastasis model of CC. OSU-03013 was administered by gavage. The pathology of the tumor tissues was assessed using HE staining and cell apoptosis was measured using TUNEL staining. EMT markers in the tumors were determined using Western Blot, and IL-1β and TNF-α were determined using ELISA. VEGF-A and VEGFR-2 in tumor tissues were measured to assess angiogenesis using immunofluorescence. HE staining was conducted to detect the effect of OSU-03013 on liver metastasis. Western Blot assay was performed to determine the expression of Wnt2, β-catenin and GSK-3β. OSU-03013 reduced inflammatory cell infiltration and inhibited IL-1β and TNF-α production by modulating the Wnt/β-catenin pathway. OSU-03013 induced apoptosis of cancer cells in tumor tissues and possessed anti-angiogenic activity. OSU-03013 treatment reduced the number and size of metastatic nodules of cancer cells in liver tissues. OSU-03013 may inhibit tumor growth and angiogenesis through the Wnt3a/β-catenin pathway in CC nude mice.

Myricetin-loaded SBA-15 silica nanoparticles for enhanced management of pyrexia, pain, and inflammation through modulation of MAPK/NF-κB and COX-2/PGE-2 pathways: Evidence from the biochemical, histological, and metabolomic analysis

Myricetin (MYR) is a natural flavonoid that has several biological functions. However, some of its beneficial effects are diminished due to low water solubility, stability, and bioavailability. Herein, several kinds of silica nanoparticles (MCM-41 and SBA-15) were loaded with MYR to improve its biological activity as an analgesic, antipyretic, and anti-inflammatory component, thereby overcoming its drawbacks. The nanoparticles (MYR@SBA-15) were formulated optimally, transforming MYR into an amorphous state. This transformation was confirmed via several strategies, including differential scanning calorimetry, Fourier transform infrared spectroscopy, and powder x-ray diffraction. As a result, there was a significant enhancement in the solubility and rate of dissolution in water. The anti-inflammatory benefits as an innovative strategy and the underlying mechanism of action of MYR and its SBA-15 silica nanoparticles (MYR@SBA-15) were investigated based on the biochemical, histological, immunohistochemical, and metabolomic assays alongside their antipyretic and analgesic characteristics. Compared to the usage of raw MYR, the administration of MYR@SBA-15 at doses of 25, 50, and 100 mg/kg significantly decreases pain perception by inhibiting the body’s writhing motions induced by acetic acid. Furthermore, it helps regulate increased body temperature caused by baking yeast and effectively stabilizes it. It reduces the release of NO and PGE-2 in a concentration-dependent manner by down-regulating iNOS and COX-2 expression in the inflammatory model. MYR and MYR@SBA-15 also inhibit the nuclear translocation of NF-κB, downregulate the expression of mitogen-activated protein kinases (MAPKs), such as p38, ERK1/2, and JNK protein, and reduce the generation of proinflammatory cytokines, such as TNF-α. In addition, inflammatory cardinal signs like paw edema caused by carrageenan in rats are greatly suppressed by MYR and MYR@SBA-15 treatment when compared to the untreated group. More noteworthy outcomes are shown in the MYR@SBA-15, particularly at a dose of 100 mg/kg. These results of biochemical and immuno-histochemistry suggest that MYR@SBA-15 may be a useful analgesic antipyretic and may also help reduce inflammation by altering MAPKs/NF-κB and COX-2/PGE-2 signaling cascades. Serum metabolomics study demonstrated modifications in various low molecular weight metabolites with arthritis development. These metabolite levels were restored to normal when MYR@SBA-15 was administered via modulating several metabolic pathways, i.e., pyrimidine, energy metabolism, and proteins. Overall, MYR-loaded SBA-15 silica nanoparticles have demonstrated significant promise in enhancing the disturbed metaboloic pathways and providing a substantial capacity to regulate several oxidative stress and inflammatory mediators.

Investigation of Cyclooxygenase-2 Expression in Tissue: Protein and mRNA Levels Compared Between Patients with Oral Squamous Cell Carcinoma and Oral Lichen Planus

Aim: Cyclooxygenase-2 (COX-2) is a crucial enzyme in the prostaglandin cascade. Overexpression of the COX-2 enzyme has been associated with the pathogenesis and progression of certain cancers, including oral cancer. This study aimed to investigate the quantitative expression and immunohistochemistry (IHC) expression of COX-2 in tissue samples from patients with oral squamous cell carcinoma (OSCC) and oral lichen planus (OLP) to gain insight into its potential role in the pathogenesis of these oral diseases. Methods: A total of 76 samples were analyzed, consisting of 25 cases of OSCC, 27 cases of OLP, and 24 cases of normal oral mucosa. COX-2 expression was analyzed using IHC staining and quantitative polymerase chain reaction (qPCR). Statistical analysis was performed using the Chi-squared, Spearman’s, and Fisher’s exact tests, with significance declared at a P value of &lt;.05. Results: The mRNA expression of COX-2 in OSCC tissues (3.17 ± 1.02) was found to be significantly higher than in OLP (1.65 ± 0.72) and normal (1.08 ± 0.79; P &lt; .01). In addition, protein expression of COX-2 was significantly higher in cancer tissues than in normal and OLP ( P &lt; .05). The oral cavity was the most common tumor site in the studied cases, representing 56% of OSCC cases, as determined by qPCR analysis ( P &lt; .05). Conclusion: Understanding the involvement of COX-2 in these oral diseases has implications for the development of targeted therapies and personalized treatment approaches. Also, the identification of COX-2 as a potential biomarker may contribute to improved diagnostic accuracy and prognosis in patients with OSCC and OLP. Moreover, the qPCR method could be as effective a technique as IHC to evaluate COX-2 amplification.

Demethylzeylasteral alleviates inflammation and colitis via dual suppression of NF-κB and STAT3/5 by targeting IKKα/β and JAK2

BackgroundUlcerative colitis (UC) is a common inflammatory bowel disease and a risk factor of colorectal cancer. Demethylzeylasteral (DZT), a bioactive component mainly isolated from Tripterygium wilfordii, has been shown to inhibit inflammation and cancer. However, its anti-UC function and molecular mechanisms have not been well characterized. This study aims to explore the therapeutic effect and functional targets of demethylzeylasteral against UC. MethodsRT-qPCR, Western blot and ELISA were used to detect the generation of pro-inflammatory cytokines and chemokines in murine macrophage cells. Luciferase reporter gene, Western blot, pull-down, CETSA, DARTS, and virtual docking were employed to detect the anti-inflammatory targets and molecular mechanisms of demethylzeylasteral. The anti-inflammatory and anti-colitis effects of demethylzeylasteral were further determined in DSS-challenged mice. ResultsIn vitro, demethylzeylasteral inhibited NO and PGE2 production by suppressing the mRNA and protein expression of iNOS and COX-2, and suppressed the mRNA expression of TNF-α, IL-1β, IL-6, MCP-1, CXCL9, and CXCL10 in RAW264.7 macrophages stimulated by LPS/IFNγ. Furthermore, demethylzeylasteral was not only capable of inhibiting IKKα/β-NF-κB activation, but also able to block JAKs-STAT3/5 activation in LPS/INFγ-incubated RAW264.7 cells or DSS-exposed colon tissues of mice. Mechanistically, demethylzeylasteral was found to directly bind to IKKα/β and JAK2 kinases, leading to inactivation of pro-inflammatory signaling cascades and reduced generation of cytokines and chemokines. In vivo, oral administration of demethylzeylasteral significantly attenuated DSS-induced colitis, which was mainly manifested as mitigated symptoms of colitis, colonic mucosal barrier damage, and colonic inflammation. ConclusionWe demonstrated that demethylzeylasteral alleviated UC pathology by blocking NF-κB and STAT3/5 pathways via targeting IKKα/β and JAK2 kinases, raising the possibility that demethylzeylasteral could act as a candidate for the treatment of UC.

Indoxyl sulfate induces retinal microvascular injury via COX-2/PGE2 activation in diabetic retinopathy

BackgroundDiabetic retinopathy (DR), the principal cause of acquired blindness among the working-age population, is the most frequent microvascular complication of diabetes. Although metabolic disorders are hypothesized to play a role in its pathogenesis, the underlying mechanism remains largely elusive.MethodsTo elucidate the mechanism, we initially compared metabolite profiles of vitreous fluid between 23 patients with DR and 12 non-diabetic controls using liquid chromatography/tandem mass spectrometry, identifying the distinct metabolite indoxyl sulfate (IS). Subsequently, streptozotocin (STZ)-induced diabetic and IS-injected rat models were established to examine the effects of IS on retinal microvasculature. RNA sequencing was conducted to identify potential regulatory mechanisms in IS-treated human retinal endothelial cells (HREC). Finally, target gene knockdown in HREC and treatment of IS-injected rats with inhibitors (targeting IS production or downstream regulators) were employed to elucidate the detailed mechanisms and identify therapeutic targets for DR.ResultsMetabolomics identified 172 significantly altered metabolites in the vitreous humor of diabetics, including the dysregulated tryptophan metabolite indoxyl sulfate (IS). IS was observed to breach the blood-retinal barrier and accumulate in the intraocular fluid of diabetic rats. Both in vivo and in vitro experiments indicated that elevated levels of IS induced endothelial apoptosis and disrupted cell junctions. RNA sequencing pinpointed prostaglandin E2 (PGE2) synthetase-cyclooxygenase 2 (COX-2) as a potential target of IS. Validation experiments demonstrated that IS enhanced COX-2 expression, which subsequently increased PGE2 secretion by promoting transcription factor EGR1 binding to COX-2 DNA following entry into cells via organic anion transporting polypeptides (OATP2B1). Furthermore, inhibition of COX-2 in vivo or silencing EGR1/OATP2B1 in HREC mitigated IS-induced microcapillary damage and the activation of COX-2/PGE2.ConclusionOur study demonstrated that indoxyl sulfate (IS), a uremic toxin originating from the gut microbiota product indole, increased significantly and contributed to retinal microvascular damage in diabetic retinopathy (DR). Mechanistically, IS impaired retinal microvascular integrity by inducing the expression of COX-2 and the production of PGE2. Consequently, targeting the gut microbiota or the PGE2 pathway may offer effective therapeutic strategies for the treatment of DR.Graphical

Linoleic Acid Induces Metabolic Reprogramming and Inhibits Oxidative and Inflammatory Effects in Keratinocytes Exposed to UVB Radiation.

Linoleic acid (LA), the primary ω-6 polyunsaturated fatty acid (PUFA) found in the epidermis, plays a crucial role in preserving the integrity of the skin's water permeability barrier. Additionally, vegetable oils rich in LA have been shown to notably mitigate ultraviolet (UV) radiation-induced effects, including the production of reactive oxygen species (ROS), cellular damage, and skin photoaging. These beneficial effects are primarily ascribed to the LA in these oils. Nonetheless, the precise mechanisms through which LA confers protection against damage induced by exposure to UVB radiation remain unclear. This study aimed to examine whether LA can restore redox and metabolic equilibria and to assess its influence on the inflammatory response triggered by UVB radiation in keratinocytes. Flow cytometry analysis unveiled the capacity of LA to diminish UVB-induced ROS levels in HaCaT cells. GC/MS-based metabolomics highlighted significant metabolic changes, especially in carbohydrate, amino acid, and glutathione (GSH) metabolism, with LA restoring depleted GSH levels post-UVB exposure. LA also upregulated PI3K/Akt-dependent GCLC and GSS expression while downregulating COX-2 expression. These results suggest that LA induces metabolic reprogramming, protecting against UVB-induced oxidative damage by enhancing GSH biosynthesis via PI3K/Akt signaling. Moreover, it suppresses UVB-induced COX-2 expression in HaCaT cells, making LA treatment a promising strategy against UVB-induced oxidative and inflammatory damage.

The Effect of Increasing Aerobic Exercise on the Expression of NF-κB and COX-2 Genes in Heart Tissue of Rats Under a High-fat Diet

Background: Several studies have shown that obesity alters the function and structure of the heart. Objectives: This study examined the impact of increasing aerobic exercise (IAE) on the mRNA expression of Cyclooxygenase-2 (COX-2) and nuclear factor Kappa B (NF-κB) in the cardiac tissue of rats fed a high-fat diet (HFD). Methods: Twenty-four male Wistar rats were divided into two groups and fed two types of diets for eight weeks: Control and HFD groups. After eight weeks, the rats on the HFD were further divided into HFD and HFD + IAE groups. The exercise program was conducted for six weeks, with five sessions per week, progressing from moderate to high intensity. The program followed the principle of gradual overload and was based on the maximum speed of the rats. The expression of COX-2 and NF-κB genes was assessed. Results: The expression of COX-2 and NF-κB genes increased in the HFD group compared to the control group. After six weeks, the expression of NF-κB and COX-2 genes decreased in the HFD + IAE group compared to the HFD group. Conclusions: Six weeks of IAE appears to reduce the inflammatory process in rats with HFD-induced obesity.

Activation Pathways of Murine Macrophages by Lipophosphoglycan from Strains of Leishmania major (FV1 and LV39).

Lipophosphoglycan (LPG) is an important Leishmania virulence factor. It is the most abundant surface glycoconjugate in promastigotes, playing an important role in the interaction with phagocytic cells. While LPG is known to modulate the macrophage immune response during infection, the activation mechanisms triggered by this glycoconjugate have not been fully elucidated. This work investigated the role that LPGs purified from two strains of Leishmania major (FV1 and LV39) play in macrophage activation, considering the differences in their biochemical structures. Bone marrow-derived macrophages from BALB/c mice were stimulated with 10 μg/mL purified LPG from the LV39 and FV1 strains. We then measured the production of nitric oxide (NO) and cytokines, the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the activation of MAPK pathways. LPG from the LV39 strain, which has longer poly-galactosylated side chains, induced a more pro-inflammatory profile than that from the FV1 strain. This included higher production of NO, TNF-α, and PGE2, and increased expression of COX-2 and iNOS. Additionally, the phosphorylation of ERK-1/2 and JNK was elevated in macrophages exposed to LPG from the LV39 strain. No difference in IL-10 production was observed in cells stimulated by both LPG. Thus, intraspecific structural differences in LPG contribute to distinct innate immune responses in macrophages.

ARL11 knockdown alleviates spinal cord injury by inhibiting neuroinflammation and M1 activation of microglia in mice

Spinal cord injury (SCI) is a severe central nervous system injury and microglia are major participants in neuroinflammation after injury. ADP-ribosylation factor-like GTPase 11 (ARL11) is a GTP-binding protein. Whether ARL11 is involved in the SCI progression is unknown. In the impactor-induced moderate SCI mouse model, ARL11 protein and mRNA expression were significantly increased in the injury site. LPS (100 ng/mL) and IFN-γ (20 ng/mL) were incubated with BV2 cells (immortalized mouse microglial cell line) to drive them into an M1-like phenotype. ARL11 up-regulation was also observed in activated microglia in SCI mice and LPS and IFN-γ treated BV2 cells. Basso Mouse Scale scores and inclined plate test revealed that ARL11 deletion promoted motor function recovery in SCI mice. Pathological examination showed ARL11 knockdown reduced spinal cord tissue damage, increased neuron numbers, and inhibited neuronal apoptosis in SCI mice. ARL11 knockdown notably inhibited IL-1β and IL-6 production in vivo and in vitro. Furthermore, ARL11 deletion significantly inhibited iNOS protein and mRNA expression in vivo and in vitro, and COX-2 expression in vivo. Mechanism studies revealed that ARL11 silencing decreased phosphorylated ERK1/2 protein expression. Additionally, ELF1 knockdown significantly inhibited ARL11 protein and mRNA expression in vitro. ELF1 acted as a transcription activator in regulating ARL11 expression by binding to the promoter. In conclusion, ARL11 knockdown protects neurons by inhibiting M1 microglia-induced neuroinflammation, thereby promoting motor functional recovery in SCI mice. This may occur in part under the regulation of ELF1. Our study provides a new molecular target for SCI treatment.

Short-Term Treatment of Melatonin Improves the Expression of Cell Adhesion Molecules in the Testis of the Mouse Cryptorchidism Model.

Melatonin plays a major role in regulating the sleep-wake cycle and enhancing testosterone production. We investigated the short-term effects of melatonin treatment for 14 consecutive days in the cryptorchidism model. We categorized experimental mice into Sham (S), Orchiopexy (O), Melatonin (Mel), and Orchiopexy + Melatonin (OMel) groups. Surgery involved inducing cryptorchidism in the left testis for seven days, followed by orchiopexy. The Mel group's testes did not descend, but they received melatonin injections after seven days of cryptorchidism. The OMel group underwent both orchiopexy and melatonin treatment. Both O and Mel groups exhibited decreased sperm and round-headed sperm in the epididymis. Significant increases were observed in the numbers of giant cells and negative Nectin-3 cells at p-value<0.05. The pattern of Cadm1 expression changed, and Nectin-2 and Nectin-3 co-expression was lacking in abnormal spermatids. Sertoli cell cytoplasm in both O and Mel groups exhibited autophagosomes and multivesicular bodies, which correlated with increased cyclooxygenase-2 expression. However, Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cell numbers increased significantly in all treatment groups compared to the S group. Our study found that the combination of orchiopexy and melatonin positively influenced the expression of cell adhesion molecules (Cadm1, Nectin-2, and Nectin-3) involved in spermatogenesis, while reducing giant cells, autophagosomes, and apoptosis.