OBJECTIVE: To investigate the effects and underlying mechanisms of VX765 on osteoarthritis (OA) and chondrocytes inflammation in rats. METHODS: Chondrocytes were isolated from the knee joints of 4-week-old Sprague Dawley (SD) rats. The third-generation cells were subjected to cell counting kit 8 (CCK-8) analysis to assess the impact of various concentrations (0, 1, 5, 10, 20, 50, 100 μmol/L) of VX765 on rat chondrocyte activity. An in vitro lipopolysaccharide (LPS) induced cell inflammation model was employed, dividing cells into control group, LPS group, VX765 concentration 1 group and VX765 concentration 2 group without obvious cytotoxicity. Western blot, real-time fluorescence quantitative PCR, and ELISA were conducted to measure the expression levels of inflammatory factors-transforming growth factor β ₁ (TGF-β ₁), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α). Additionally, Western blot and immunofluorescence staining were employed to assess the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1). Thirty-two SD rats were randomly assigned to sham surgery group (group A), OA group (group B), OA+VX765 (50 mg/kg) group (group C), and OA+VX765 (100 mg/kg) group (group D), with 8 rats in each group. Group A underwent a sham operation with a medial incision, while groups B to D underwent additional transverse incisions to the medial collateral ligament and anterior cruciate ligament, with removal of the medial meniscus. One week post-surgery, groups C and D were orally administered 50 mg/kg and 100 mg/kg VX765, respectively, while groups A and B received an equivalent volume of saline. Histopathological examination using HE and safranin-fast green staining was performed, and Mankin scoring was utilized for evaluation. Immunohistochemical staining technique was employed to analyze the expressions of matrix metalloproteinase 13 (MMP-13) and collagen type Ⅱ. RESULTS: The CCK-8 assay indicated a significant decrease in cell viability at VX765 concentrations exceeding 10 μmol/L ( P<0.05), so 4 μmol/L and 8 μmol/L VX765 without obvious cytotoxicity were selected for subsequent experiments. Following LPS induction, the expressions of TGF-β ₁, IL-6, and TNF-α in cells significantly increased when compared with the control group ( P<0.05). However, intervention with 4 μmol/L and 8 μmol/L VX765 led to a significant decrease in expression compared to the LPS group ( P<0.05). Western blot and immunofluorescence staining demonstrated a significant upregulation of Nrf2 pathway-related molecules Nrf2 and HO-1 protein expressions by VX765 ( P<0.05), indicating Nrf2 pathway activation. Histopathological examination of rat knee joint tissues and immunohistochemical staining revealed that, compared to group B, treatment with VX765 in groups C and D improved joint structural damage in rat OA, alleviated inflammatory reactions, downregulated MMP-13 expression, and increased collagen type Ⅱ expression. CONCLUSION VX765 can improve rat OA and reduce chondrocyte inflammation, possibly through the activation of the Nrf2 pathway.
Rats ; Animals ; Chondrocytes/metabolism* ; Matrix Metalloproteinase 13/metabolism* ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha/metabolism* ; Collagen Type II/metabolism* ; Interleukin-6 ; Lipopolysaccharides/pharmacology* ; NF-E2-Related Factor 2/pharmacology* ; Inflammation/drug therapy* ; Osteoarthritis/metabolism* ; Transforming Growth Factor beta1/metabolism* ; Dipeptides ; para-Aminobenzoates

This study aimed to investigate the protective effect and underlying mechanism of Mailuo Shutong Pills(MLST) on posterior limb swelling caused by femur fracture in rats. The rats were randomly divided into a sham operation group, a model group, a low-dose MLST group(1.8 g·kg~(-1)·d~(-1)), a high-dose MLST group(3.6 g·kg~(-1)·d~(-1)), and a positive drug group(60 mg·kg~(-1)·d~(-1) Maizhiling Tablets). The femur in the sham operation group was exposed and the wound was sutured, while the other four groups underwent mechanical damage to cause femur fracture. The rats were treated with corresponding drugs by gavage 7 days before modeling and 5 days after modeling, while those in the sham operation group and the model group were given an equivalent dose of distilled water by gavage. Hematoxylin-eosin(HE) staining was used to detect the pathological injury of the posterior limb muscle tissues in rats, and the degree of hind limb swelling was measured. The enzyme-linked immunosorbent assay(ELISA) kit was used to detect the expression levels of interleukin-6(IL-6), interleukin-1β(IL-1β), and tumor necrosis factor-α(TNF-α) in the serum of rats in each group. The activity of superoxide dismutase(SOD), malondialdehyde(MDA), catalase(CAT), and glutathione peroxidase(GSH-Px) in rat serum was also measured. Western blot was used to detect the protein expression levels of heme oxygenase 1(HO-1), NAD(P)H quinone oxidoreductase 1(NQO1), and nuclear transcription factor E2-related factor 2(Nrf2) in rat posterior limb muscle tissues. The changes in the intestinal flora and intestinal metabolites in rats were detected by 16S rDNA sequencing and ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS), respectively, to explore the underlying mechanism of MLST in treating posterior limb swelling caused by femur fracture in rats. Compared with the model group, MLST significantly improved the degree of posterior limb swelling in rats, reduced the levels of serum inflammatory factors, and alleviated oxidative stress injury. The HE staining results showed that the inflammatory infiltration in the posterior limb muscle tissues of rats in the MLST groups was significantly improved. Western blot results showed that MLST significantly increased the protein expression of HO-1, NQO1, and Nrf2 in rat posterior limb muscle tissues compared with the model group. The 16S rDNA sequencing results showed that MLST improved the disorder of intestinal flora in rats after femur fracture. The UPLC-MS/MS results showed that MLST significantly affected the bile acid biosynthesis and metabolism pathway in the intestine after femur fracture, and the Spearman analysis confirmed that the metabolite deoxycholic acid involved in bile acid biosynthesis was positively correlated with the abundance of Turicibacter. The metabolite cholic acid was positively correlated with the abundance of Papilibacter, Staphylococcus, and Intestinimonas. The metabolite lithocholic acid was positively correlated with Papilibacter and Intestinimonas. The above results indicated that MLST could protect against the posterior limb swelling caused by femur fracture in rats. This protective effect may be achieved by improving the pathological injury of the posterior limb muscle, reducing the expression levels of inflammatory and oxidative stress-related factors in serum, reducing the oxidative injury of the posterior limb muscle, improving intestinal flora, and balancing the biosynthesis of bile acids in the intestine.
Rats ; Animals ; NF-E2-Related Factor 2/metabolism* ; Gastrointestinal Microbiome ; Chromatography, Liquid ; Multilocus Sequence Typing ; Tandem Mass Spectrometry ; Oxidative Stress ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Femur ; Bile Acids and Salts ; DNA, Ribosomal ; Superoxide Dismutase/metabolism*

This study aims to investigate the mechanism of acacetin in protecting rats from cerebral ischemia-reperfusion injury via the Toll-like receptor 4(TLR4)/NOD-like receptor protein 3(NLRP3) signaling pathway. Wistar rats were randomized into sham, model, low-and high-dose acacetin, and nimodipine groups, with 10 rats in each group. The rat model of middle cerebral artery occlusion(MCAO) was established with the improved suture method in other groups except the sham group. The neurological deficit score and cerebral infarction volume of each group were evaluated 24 h after modeling. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of interleukin-1β(IL-1β), IL-6, tumor necrosis factor-α(TNF-α), malondialdehyde(MDA), supe-roxide dismutase(SOD), and glutathione(GSH). Western blot was employed to determine the expression levels of B-cell lymphonoma-2(Bcl-2), Bcl-2-associated X protein(Bax), and TLR4/NLRP3 signaling pathway-related proteins(TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β) in the rat brain tissue. Hematoxylin-eosin(HE) staining was employed to reveal the histopathological changes in the ischemic area. Compared with the sham group, the modeling of MCAO increased the neurological deficit score and cerebral infarction volume, elevated the IL-1β, IL-6, TNF-α, and MDA levels and lowered the SOD and GSH levels in the brain tissue(P<0.05). Compared with the MCAO model group, low-and high-dose acacetin and nimodipine decreased the neurological deficit score and cerebral infarction volume, lowered the IL-1β, IL-6, TNF-α, and MDA levels and elevated the SOD and GSH levels in the brain tissue(P<0.05). Compared with the sham group, the model group showed up-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β and down-regulated protein level of Bcl-2 in the brain tissue(P<0.05). Compared with the MCAO model group, the acacetin and nimodipine groups showed down-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β and up-regulated protein level of Bcl-2 in the brain tissue(P<0.05). In conclusion, acacetin regulates the TLR4/NLRP3 signaling pathway to inhibit neuroinflammatory response and oxidative stress, thus exerting the protective effect on cerebral ischemia-reperfusion injury in rats.
Rats ; Animals ; NF-kappa B/metabolism* ; bcl-2-Associated X Protein ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Rats, Sprague-Dawley ; Caspase 1/metabolism* ; Toll-Like Receptor 4/metabolism* ; Nimodipine/pharmacology* ; Interleukin-6 ; Rats, Wistar ; Signal Transduction ; Infarction, Middle Cerebral Artery ; Reperfusion Injury/prevention & control* ; Superoxide Dismutase/metabolism*

This study aimed to investigate the effect and underlying mechanism of Poria cocos polysaccharides(PCP) on myocardial cell apoptosis in the rat model of myocardial ischemia-reperfusion injury(MI/RI). Male SPF-grade SD rats were randomly divided into a sham group(saline), a model group(saline), low-and high-dose PCP groups(100 and 200 mg·kg~(-1)), and a fasudil group(10 mg·kg~(-1)), with 16 rats in each group. Except for the sham group, the other four groups underwent left anterior descending coronary artery ligation for 30 min followed by reperfusion for 2 h to establish the MI/RI model. The myocardial infarct area was assessed by TTC staining. Histological changes were observed through HE staining. Myocardial cell apoptosis was evaluated using TUNEL staining. Serum lactate dehydrogenase(LDH), creatine kinase MB(CK-MB), interleukin-1β(IL-1β) and IL-18 levels, myocardial superoxide dismutase(SOD) activity and malondialdehyde(MDA) levels were detected by ELISA. Protein expression of B-cell lymphoma 2(Bcl-2), Bcl-2 associated X protein(Bax), cleaved caspase-3, Ras homolog gene A(RhoA), myosin phosphatase target subunit 1(MYPT-1), phosphorylated MYPT-1(p-MYPT-1), and Rho-associated coiled-coil forming kinase 1(ROCK 1) were measured by Western blot. Pathological staining of myocardial tissue revealed that in the model group, there was focal necrosis of myocardial tissue, myocardial cell swelling, unclear boundaries, and neutrophil infiltration. These pathological changes were alleviated in the low-and high-dose PCP groups and the fasudil group. Compared with the model group, the low-and high-dose PCP groups and the fasudil group showed significantly reduced myocardial infarct area and myocardial cell apoptosis rate. Compared with the sham group, the model group exhibited elevated serum LDH, CK-MB, IL-1β and IL-18 levels, increased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and decreased myocardial SOD levels and Bcl-2 protein expression. Compared with the model group, the PCP groups and the fasudil group showed lowered serum LDH, CK-MB, IL-1β and IL-18 levels, decreased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and increased myocardial SOD levels and Bcl-2 protein expression. PCP exhibited a certain preventive effect on myocardial tissue pathological damage and myocardial cell apoptosis in MI/RI rats, possibly related to the inhibition of the Rho-ROCK signaling pathway activation, thereby reducing oxidative stress and inflammatory responses.
Rats ; Male ; Animals ; Myocardial Reperfusion Injury/drug therapy* ; bcl-2-Associated X Protein/metabolism* ; Rats, Sprague-Dawley ; Caspase 3/metabolism* ; Interleukin-18 ; Wolfiporia ; Signal Transduction ; Myocardial Infarction/drug therapy* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Creatine Kinase, MB Form ; Apoptosis ; Polysaccharides/pharmacology* ; Superoxide Dismutase/metabolism* ; 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives*

Objective To explore the effect and mechanism of penehyclidine hydrochloride (PHCD) on vascular endothelial injury in septic rats. Methods Fifty male SD rats were randomly divided into control group, lipopolysaccharide (LPS) induced sepsis group (model group), low dose PHCD (0.3 mg/kg) group, medium dose PHCD (1.0 mg/kg) group and high dose PHCD (3.0 mg/kg) groups, ten mice for each group. Normal saline was injected into the tail vein of the control group, and 10 mg/kg lipopolysaccharide (LPS) was injected into the tail vein of the rats in other groups to prepare the sepsis rat models. After the models were successfully established, low, medium and high doses (0.3, 1.0, 3.0 mg/kg) of PHCD solution were injected into the tail vein of the rats of corresponding groups. Wet/dry mass ratio (W/D) of lung tissue of rats in each group was measured, and ELISA was used to assay interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-6 content and rat plasma angiopoietin 2 (Ang2) content in bronchoalveolar lavage fluid (BALF). HE staining was used to observe the pathological changes of lung tissues. Immunohistochemical staining was used to observe the expression of Ang2 in the right lung tissues. Western blot analysis was performed to detect Ang2 and vascular endothelial cadherin (VE-cadherin) protein in lung tissues. Results Compared with the control group, the W/D ratio of the lung tissues of rats in the model group and the contents of IL-1β, IL-6 and TNF-α in BALF were significantly increased; the lung tissues showed obvious pathological damage, with up-regulation of Ang2 expression and down-regulation of VE-Cadherin expression. Compared with the model group, the W/D ratio of the lung tissues of rats in three PHCD treatment groups and the contents of IL-1β, IL-6 and TNF-α in BALF were significantly reduced; the pathological damage of lung tissue was significantly reduced, with down-regulation of Ang2 expression and up-regulation of VE-cadherin expression. Conclusion PHCD can reduce LPS-induced lung inflammation in rats with sepsis by regulating the Ang2/VE-Cadherin pathway, thereby improving vascular endothelial injury.
Rats ; Mice ; Animals ; Male ; Lipopolysaccharides/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Angiopoietin-2/pharmacology* ; Interleukin-6/metabolism* ; Rats, Sprague-Dawley ; Lung ; Acute Lung Injury/metabolism* ; Sepsis/metabolism*

OBJECTIVE: To explore the effect of human bone marrow mesenchymal stem cells (MSCs) with ectopic high OCT4 expression on T-cell proliferation, activation and secretion in vitro. METHODS: Peripheral blood mononuclear cells were isolated from healthy children. Anti-CD3 and anti-CD28 monoclonal antibodies were used to activate T lymphocytes, which were stimulated by interleukin (IL)-2 for one week in vitro. Then MSCs with ectopic high OCT4 expression (MSC-OCT4) were co-cultured with activated T lymphocytes. After one week of co-culture, the supernatant was collected and the levels of Th1/Th2 cytokines [IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α and interferon (IFN)-γ] were determined by flow cytometry. The lymphocytes after one week of co-culture were collected and counted by Countstar software. After the proportions of activated/inactivated T cell subsets were determined by flow cytometry, the absolute lymphocyte counts were calculated and expressed as mean ± standard deviation. RESULTS: Compared with control T cell alone culture group, the proliferation of CD3⁺ T cells, CD3⁺CD4⁺ T cells, and CD3⁺CD8⁺ T cells were significantly inhibited in MSC group and MSC-OCT4 group. Compared with MSC, MSC-OCT4 could inhibit CD3⁺CD8⁺ T cell proliferation better (P =0.049), and mainly inhibited early T cell activation. Compared with control T cell alone culture group, the levels of IL-2 and INF-γ were significantly down-regulated both in MSC group and MSC-OCT4 group.After co-culture with T cells for one week, the level of IL-6 significantly increased in MSC group and MSC-OCT4 group compared with that before co-culture. Compared with control MSC group, MSC-OCT4 group had higher viable cell numbers after 1 week of co-culture (P =0.019), and could resist the inhibition of proliferation by higher concentration of mitomycin C. CONCLUSION Both MSC and MSC-OCT4 can inhibit the proliferation and activation of IL-2-stimulated T cells in vitro. After overexpression of OCT4, MSC has better proliferation ability in vitro and can inhibit the proliferation of CD3⁺CD8⁺ T cells more effectively, which may have a better and more lasting immunosuppressive ability to regulate the balance of Th1/Th2.
Child ; Humans ; Bone Marrow Cells ; CD8-Positive T-Lymphocytes/metabolism* ; Cell Proliferation ; Cells, Cultured ; Interleukin-2 ; Interleukin-6/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Lymphocyte Activation ; Mesenchymal Stem Cells ; Tumor Necrosis Factor-alpha/metabolism*

OBJECTIVE: To investigate the significance of Tim-3 and Galectin-9 in Th1/Th2 imbalance in patients with multiple myeloma (MM). METHODS: 55 newly diagnosed MM patients and 20 healthy controls were included. Flow cytometry was used to detect the expression of Tim-3 on CD4⁺T cells, the proportion of Th1, Th2, Tim-3⁺Th1 and Tim-3⁺Th2 cells in peripheral blood. ELISA was used to detect the levels of cytokines IFN-γ and IL-4 in serum, and PCR was used to detect the level of Galectin-9 mRNA. Then the correlations between Galectin-9 mRNA expression and Th-cell subsets and related cytokine levels, as well as the relationship between Tim-3⁺Th1/Tim-3⁺Th2 ratio and corresponding clinical features were analyzed. RESULTS: Compared with the control group, the expression of Tim-3 on CD4⁺T cells in peripheral blood of MM patients was significantly increased (P<0.05), the proportions of Tim-3⁺Th1 cells, Tim-3⁺Th2 cells and Tim-3⁺Th1/Tim-3⁺Th2 ratio in MM patients were also increased (P<0.05), while the proportion of Th1 cells and Th1/Th2 ratio in MM patients were significantly decreased (P<0.05). The level of cytokine IFN-γ and IFN-γ/IL-4 ratio in MM patients were significantly decreased (P<0.05), while the level of cytokine IL-4 was increased (P<0.05). The mRNA levels of Galectin-9 in MM patients were significantly increased (P<0.05). The levels of Galectin-9 mRNA were positively correlated with Tim-3⁺CD4⁺T cells (r=0.663), Tim-3⁺Th2 cells (r=0.492) and IL-4 (r=0.470), while negatively correlated with IFN-γ (r=-0.593). The ratios of Tim-3⁺Th1/Tim-3⁺Th2 in MM patients were positively correlated with ISS stage (r=0.511), osteolytic damage (r=0.556) and chromosome abnormality (r=0.632). CONCLUSION These results suggest that Tim-3 and Galectin-9 are involved in Th1/Th2 imbalance in MM patients, and the high ratio of Tim-3⁺Th1/Tim-3⁺Th2 is associated with poor clinical prognosis.
Humans ; Cytokines/metabolism* ; Galectins/metabolism* ; Hepatitis A Virus Cellular Receptor 2/metabolism* ; Interleukin-4/metabolism* ; Ligands ; Multiple Myeloma/metabolism* ; RNA, Messenger/metabolism* ; Th1 Cells/metabolism* ; Th2 Cells/metabolism*

OBJECTIVE: To investigate the anti-oxidant and anti-inflammatory effects of ethanol extract of Polygala sibirica L. var megalopha Fr. (EEP) on RAW264.7 mouse macrophages. METHODS: RAW264.7 cells were pretreated with 0-200 µg/mL EEP or vehicle for 2 h prior to exposure to 1 µg/mL lipopolysaccharide (LPS) for 24 h. Nitric oxide (NO) and prostaglandin (PGE₂) production were determined by Griess reagent and enzyme-linked immunosorbent assay (ELISA), respectively. The mRNA levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor α (TNF-α), interleukin-1beta (IL-1β), and IL-6 were determined using reverse transcription polymerase chain reaction (RT-PCR). Western blot assay was used to determine the protein expressions of iNOS, COX-2, phosphorylation of extracellular regulated protein kinases (ERK1/2), c-Jun N-terminal kinase (JNK), inhibitory subunit of nuclear factor Kappa B alpha (Iκ B-α) and p38. Immunofluorescence was used to observe the nuclear expression of nuclear factor-κ B p65 (NF-κ B p65). Additionally, the anti-oxidant potential of EEP was evaluated by reactive oxygen species (ROS) production and the activities of catalase (CAT) and superoxide dismutase (SOD). The 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl (OH), superoxide anion (O₂^-) radical and nitrite scavenging activity were also measured. RESULTS: The total polyphenol and flavonoid contents of EEP were 23.50±2.16 mg gallic acid equivalent/100 g and 43.78±3.81 mg rutin equivalent/100 g. With EEP treatment (100 and 150 µg/mL), there was a notable decrease in NO and PGE₂ production induced by LPS in RAW264.7 cells by downregulation of iNOS and COX-2 mRNA and protein expressions (P<0.01 or P<0.05). Furthermore, with EEP treatment (150 µg/mL), there was a decrease in the mRNA expression levels of TNF-α, IL-1β and IL-6, as well as in the phosphorylation of ERK, JNK and p38 mitogen-activated protein kinase (MAPK, P<0.01 or P<0.05), by blocking the nuclear translocation of NF-κ B p65 in LPS-stimulated cells. In addition, EEP (100 and 150 µg/mL) led to an increase in the anti-oxidant enzymes activity of SOD and CAT, with a concomitant decrease in ROS production (P<0.01 or P<0.05). EEP also indicated the DPPH, OH, O₂^- radical and nitrite scavenging activity. CONCLUSION EEP inhibited inflammatory responses in activated macrophages through blocking MAPK/NF-κ B pathway and protected against oxidative stress.
Animals ; Mice ; Antioxidants/pharmacology* ; Lipopolysaccharides/pharmacology* ; Polygala ; Transcription Factor RelA/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Ethanol/chemistry* ; Interleukin-6/metabolism* ; Anti-Inflammatory Agents/chemistry* ; Reactive Oxygen Species/metabolism* ; Cyclooxygenase 2/metabolism* ; Nitrites/metabolism* ; NF-kappa B/metabolism* ; Nitric Oxide/metabolism* ; Superoxide Dismutase/metabolism* ; RNA, Messenger ; Nitric Oxide Synthase Type II/metabolism*

OBJECTIVE: To investigate whether ferroptosis exists in sepsis induced intestinal injury, and to verify the association between ferroptosis in sepsis induced intestinal injury and intestinal inflammation and barrier function by stimulating and inhibiting the nuclear factor E2-related factor 2/glutathione peroxidase 4 (Nrf2/GPX4) pathway. METHODS: Forty-eight SPF grade male Sprague-Darvley (SD) rats with a body weight of 220-250 g were divided into sham operation group (Sham group), sepsis group (CLP group), sepsis+iron chelating agent deferoxamine (DFO) group (CLP+DFO group) and sepsis+ferroptosis inducer Erastin group (CLP+Erastin group) using a random number table method, with 12 rats in each group. The sepsis model was established by cecal ligation and puncture (CLP). The Sham group was only performed with abdominal opening and closing operations. After modeling, the CLP+DFO group received subcutaneous injection of 20 mg/kg of DFO, the CLP+Erastin group was intraperitoneally injected with 20 mg/kg of Erastin. Each group received subcutaneous injection of 50 mg/kg physiological saline for fluid resuscitation after surgery, and the survival status of the rats was observed 24 hours after surgery. At 24 hours after model establishment, 6 rats in each group were selected. First, live small intestine tissue was taken for observation of mitochondrial morphology in smooth muscle cells under transmission electron microscopy and determination of reactive oxygen species (ROS). Then, blood was collected from the abdominal aorta and euthanized. The remaining 6 rats were sacrificed after completing blood collection from the abdominal aorta, and then small intestine tissue was taken. Western blotting was used to detect the expression of intestinal injury markers such as Claudin-1 and ferroptosis related proteins GPX4 and Nrf2. Observe the pathological changes of small intestine tissue using hematoxylin-eosin (HE) staining and complete Chiu score; Detection of tumor necrosis factor-α (TNF-α), interleukins (IL-1β, IL-6) levels in serum using enzyme-linked immunosorbent assay (ELISA). The levels of serum iron ions (Fe³⁺), malondialdehyde (MDA), and D-lactate dehydrogenase (D-LDH) were measured. RESULTS: (1) Compared with the Sham group, the 24-hour survival rate of rats in the CLP group and CLP+Erastin group significantly decreased (66.7%, 50.0% vs. 100%, both P < 0.05), while there was no significant difference in the CLP+DFO group (83.3% vs. 100%, P = 0.25). (2) Western blotting results showed that compared with the Sham group, the expressions of GPX4 and Claudin-1 in the small intestine tissue of the CLP group, CLP+DFO group, and CLP+Erastin group decreased significantly, while the expression of Nrf2 increased significantly (GPX4/β-actin: 0.56±0.02, 1.03±0.01, 0.32±0.01 vs. 1.57±0.01, Claudin-1/β-actin: 0.60±0.04, 0.96±0.07, 0.41±0.01 vs. 1.40±0.01, Nrf2/β-actin: 0.88±0.02, 0.72±0.01, 1.14±0.01 vs. 0.43±0.02, all P < 0.05). Compared with the CLP group, the expressions of GPX4 and Claudin-1 were significantly increased in the CLP+DFO group, while the expression of Nrf2 was significantly reduced. In the CLP+Erastin group, the expressions of GPX4 and Claudin-1 further decreased, while the expression of Nrf2 further increased (all P < 0.05). (3) Under the light microscope, compared with the Sham group, the CLP group, CLP+DFO group, and CLP+Erastin group showed structural disorder in the small intestinal mucosa and submucosal tissue, significant infiltration of inflammatory cells, and destruction of glandular and villous structures. The Chui score was significantly higher (3.25±0.46, 2.00±0.82, 4.50±0.55 vs. 1.25±0.45, all P < 0.05). (4) Under transmission electron microscopy, compared with the Sham group, the mitochondria in the other three groups of small intestinal smooth muscle cells showed varying degrees of volume reduction, increased membrane density, and reduced or disappeared cristae. The CLP+Erastin group showed the most significant changes, while the CLP+DFO group showed only slight changes in mitochondrial morphology. (5) Compared to the Sham group, the CLP group, CLP+DFO group, and CLP+Erastin group had serum levels of TNF-α, IL-1β, IL-6, MDA, D-LDH, and ROS in small intestine tissue were significantly increased, while the serum Fe³⁺ content was significantly reduced [TNF-α (ng/L): 21.49±1.41, 17.24±1.00, 28.66±2.72 vs. 14.17±1.24; IL-1β (ng/L): 108.40±3.09, 43.19±8.75, 145.70±11.00 vs. 24.50±5.55; IL-6 (ng/L): 112.50±9.76, 45.90±6.52, 151.80±9.38 vs. 12.89±6.11; MDA (μmol/L): 5.61±0.49, 3.89±0.28, 8.56±1.17 vs. 1.86±0.41; D-LDH (kU/L): 39.39±3.22, 25.38±2.34, 53.29±10.53 vs. 10.79±0.52; ROS (fluorescence intensity): 90 712±6 436, 73 278±4 775, 110 913±9 287 vs. 54 318±2 226; Fe³⁺ (μmol/L): 22.19±1.34, 34.05±1.94, 12.99±1.08 vs. 51.74±11.07; all P < 0.05]. Compared with CLP group, the levels of TNF-α, IL-1β, IL-6, MDA, D-LDH and ROS in CLP+Erastin group were further increased, and the content of Fe³⁺ was further decreased, the CLP+DFO group was the opposite (all P < 0.05). CONCLUSIONS Ferroptosis exists in the intestinal injury of septic rats, and stimulating or inhibiting ferroptosis through the Nrf2/GPX4 pathway can effectively intervene in the inflammatory state and intestinal mechanical barrier of the body.
Rats ; Male ; Animals ; NF-E2-Related Factor 2 ; Tumor Necrosis Factor-alpha ; Ferroptosis ; Reactive Oxygen Species ; Actins ; Claudin-1 ; Interleukin-6 ; Sepsis/metabolism* ; Iron

OBJECTIVES: To investigate the effects and molecular mechanisms of asiatic acid on β-cell function in type 2 diabetes mellitus (T2DM). METHODS: The T2DM model was established by high fat diet and streptozotocin injection in ICR mice, and the effects of asiatic acid on glucose regulation were investigated in model mice. The islets were isolated from palmitic acid-treated diabetic mice. ELISA was used to detect the glucose-stimulated insulin secretion, tumor necrosis factor (TNF)-α and interleukin (IL)-6. ATP assay was applied to measure ATP production, and Western blotting was used to detect protein expression of mature β cell marker urocortin (Ucn) 3 and mitofusin (Mfn) 2. The regulatory effects of asiatic acid on glucose-stimulated insulin secretion (GSIS) and Ucn3 expression were also investigated after siRNA interference with Mfn2 or treatment with TNF-α. RESULTS: Asiatic acid with the dose of 25 mg·kg^－1·d^－1 had the best glycemic control in T2DM mice and improved the homeostasis model assessment β index. Asiatic acid increased the expression of Mfn2 and Ucn3 protein and improved the GSIS function of diabetic β cells in vitro and in vivo (both P<0.05). Moreover, it improved the ATP production of islets of T2DM mice in vitro (P<0.05). Interfering Mfn2 with siRNA blocked the up-regulation of Ucn3 and GSIS induced by asiatic acid. Asiatic acid inhibited islet TNF-α content and increased Mfn2 and Ucn3 protein expression inhibited by TNF-α. CONCLUSIONS Asiatic acid improves β cell insulin secretion function in T2DM mice by maintaining the β cell maturity, which may be related to the TNF-α/Mfn2 pathway.
Mice ; Animals ; Insulin Secretion ; Diabetes Mellitus, Type 2/drug therapy* ; Islets of Langerhans/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Insulin/therapeutic use* ; Diabetes Mellitus, Experimental ; Mice, Inbred ICR ; Glucose/therapeutic use* ; Interleukin-6/metabolism* ; RNA, Small Interfering/pharmacology* ; Adenosine Triphosphate ; GTP Phosphohydrolases/therapeutic use*