OBJECTIVES: Hypoxia/reoxygenation (H/R) injury is a critical pathological process during liver transplantation. Kazinol B has known anti-inflammatory, anti-apoptotic, and metabolic regulatory properties, but its protective mechanism in H/R-induced liver injury remains unclear. This study aims to investigate the protective effects and underlying mechanisms of Kazinol B in H/R-induced hepatocyte injury. METHODS: An ischemia-reperfusion model was established in healthy adult male Sprague-Dawley rats, and an in vitro H/R model was created using cultured hepatocytes. Hepatocytes were treated with Kazinol B (0-100 μmol/L) to assess cytotoxicity and protective effects. Cell viability was evaluated using the cell counting kit-8 (CCK-8) and lactate dehydrogenase (LDH) release assays. Expression of apoptosis-related proteins, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated death promoter (Bad), and cleaved caspase-3, was detected by Western blotting. Reactive oxygen species (ROS) levels were assessed via fluorescence probes, and inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were measured using enzyme-linked immunosorbent assay (ELISA). TdT-mediated nick end labeling (TUNEL) staining was performed to assess DNA damage and apoptosis. RESULTS: Kazinol B had no significant effect on hepatocyte viability at 0-50 μmol/L, but showed cytotoxicity at 100 μmol/L (P<0.05). At 0.1-20 μmol/L, Kazinol B significantly improved cell survival, reduced LDH release, decreased apoptosis, and attenuated DNA damage (all P<0.001). At 10 μmol/L, Kazinol B markedly down-regulated Bad and cleaved caspase-3 (both P<0.05), and up-regulated Bcl-2 (P<0.01). It also dose-dependently reduced ROS levels and inflammatory cytokines TNF-α and IL-1β (all P<0.01). Both in vitro and in vivo, Kazinol B inhibited activation of the c-Jun N-terminal kinase (JNK) pathway without affecting extracellular regulated protein kinase (ERK) signaling (P>0.05). TUNEL staining showed that the protective effect of Kazinol B against apoptosis was partially reversed by the JNK agonist anisomycin (P<0.01). CONCLUSIONS Kazinol B mitigates hepatocyte injury induced by H/R by inhibiting the JNK signaling pathway. Its protective effect is associated with suppression of oxidative stress and inflammation, indicating its potential as a hepatoprotective agent.
Animals ; Hepatocytes/pathology* ; Rats, Sprague-Dawley ; Male ; Rats ; Reperfusion Injury/prevention & control* ; Apoptosis/drug effects* ; Reactive Oxygen Species/metabolism* ; MAP Kinase Signaling System/drug effects* ; Cell Survival/drug effects* ; Cell Hypoxia ; Cells, Cultured

Rosacea is a common chronic inflammatory skin disease that predominantly affects the central face. It can impair appearance and cause various discomforts, thus negatively impacting patients' physical and mental well-being as well as their quality of life. Its pathophysiological mechanisms involve multiple factors. Studies have confirmed that ultraviolet radiation plays a significant role in the pathogenesis of rosacea, affecting skin tissues, cells, DNA, and proteins, and inducing oxidative damage. Ultraviolet can lead to the occurrence and development of rosacea by up-regulating the expression of LL-37, matrix metalloproteinase, vascular endothelial growth factor, and reactive oxygen species, and influence their interactions, thereby triggering inflammatory responses, altering the dermal matrix, and promoting capillary dilation and neovascularization, which contribute to the onset and progression of rosacea. Exploring the role of ultraviolet in the pathogenesis of rosacea can provide new strategies for protection and treatment, and enhance awareness of ultraviolet protection among patients with rosacea.
Humans ; Rosacea/metabolism* ; Ultraviolet Rays/adverse effects* ; Cathelicidins ; Reactive Oxygen Species/metabolism* ; Antimicrobial Cationic Peptides/metabolism* ; Matrix Metalloproteinases/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Skin/metabolism*

OBJECTIVES: Acute lung injury (ALI) is an acute respiratory failure syndrome characterized by impaired gas exchange. Due to the lack of effective targeted drugs, it is associated with high mortality and poor prognosis. Tripterygium wilfordii (TW) has demonstrated anti-inflammatory activity in the treatment of various diseases. This study aims to investigate the effects and underlying mechanisms of TW on myeloid-derived suppressor cells (MDSCs) in ALI, providing experimental evidence for TW as a potential adjuvant therapy for ALI. METHODS: Eighteen specific pathogen-free (SPF) C57BL/6 mice were randomly divided into normal control (NC; intranasal saline), lipopolysaccharide (LPS; 5 mg/kg intranasally to induce ALI), and LPS+TW (50 mg/kg TW by gavage on the first day of modeling, followed by 5 mg/kg LPS intranasally to induce ALI) groups (n=6 each). Lung injury and edema were assessed by histopathological scoring and wet-to-dry weight ratio. Cytokine levels [interleukin (IL)-1β, IL-6, IL-18, tumor necrosis factor-α (TNF-α)] in lung tissue lavage fluid were measured by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was used to assess the proportions of MDSCs, polymorphonuclear MDSCs (PMN-MDSCs), and monocytic MDSCs (M-MDSCs) in bone marrow, spleen, peripheral blood, and lung tissue, as well as reactive oxygen species (ROS) levels in lung tissues. Messenger RNA (mRNA) expression levels of inducible nitric oxide synthase (iNOS) and arginase-1 (ARG-1) in lung tissues were determined by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). PMN-MDSCs sorted from the lungs of LPS-treated mice were co-cultured with splenic CD3⁺ T cells and divided into NC, triptolide (TPL)-L, and TPL-H groups, with bovine serum albumin, 25 nmol/L TPL, and 50 nmol/L TPL, respectively. Flow cytometry was used to detect the effect of PMN-MDSCs on T-cell proliferation, and RT-qPCR was used to measure iNOS and ARG-1 mRNA expression. RESULTS: Compared with the NC group, the LPS group showed marked lung pathology with significantly increased histopathological scores and wet-to-dry ratios (both P<0.001). TW treatment significantly alleviated lung injury and reduced both indices compared with the LPS group (both P<0.05). Cytokine levels were significantly decreased in the LPS+TW group compared with the LPS group (all P<0.001). The proportions of MDSCs in CD45⁺ cells from spleen, bone marrow, peripheral blood, and lung, as well as PMN-MDSCs from spleen, peripheral blood, and lung, were significantly reduced in the LPS+TW group compared with the LPS group (all P<0.05), accompanied by reduced ROS levels in lung tissues (P<0.001). iNOS and ARG-1 mRNA expression in lung tissues was significantly lower in the LPS+TW group than in the LPS group (both P<0.001). In vitro, compared with the TPL-L group, the TPL-H group showed significantly increased CD3⁺ T-cell proliferation (P<0.001), and decreased iNOS and ARG-1 mRNA expression (all P<0.05). CONCLUSIONS TW alleviates the progression of LPS-induced ALI in mice, potentially by reducing the proportion of MDSCs in lung tissues and attenuating the immunosuppressive function of PMN-MDSCs.
Animals ; Acute Lung Injury/chemically induced* ; Myeloid-Derived Suppressor Cells/cytology* ; Tripterygium/chemistry* ; Mice, Inbred C57BL ; Mice ; Cell Differentiation/drug effects* ; Male ; Lipopolysaccharides ; Nitric Oxide Synthase Type II/genetics* ; Cytokines/metabolism* ; Reactive Oxygen Species/metabolism* ; Diterpenes/pharmacology* ; Epoxy Compounds ; Phenanthrenes

OBJECTIVES: The application of photodynamic therapy in solid tumors has attracted increasing attention in recent years, and the efficiency of photosensitizers is a crucial determinant of therapeutic efficacy. This study aims to evaluate the cytotoxic effects of a novel photosensitizer, PEG-MTPABZ-PyC, in photodynamic therapy against gastric cancer cells. METHODS: Gastric cancer MKN45 cells were treated with PEG-MTPABZ-PyC. A high-content live-cell imaging system was used to assess the cellular uptake kinetics and subcellular localization of the photosensitizer. The cytotoxic effects of PEG-MTPABZ-PyC-mediated photodynamic therapy were examined using the cell counting kit-8 (CCK-8) assay and flow cytometry, while the intrinsic cytotoxicity of the photosensitizer alone was verified by the CCK-8 assay. Intracellular reactive oxygen species (ROS) generation after photodynamic therapy was detected using 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA). RESULTS: PEG-MTPABZ-PyC alone exhibited no cytotoxicity toward MKN45 cells, indicating excellent cytocompatibility. The compound efficiently entered cells within 6 hours and localized predominantly in lysosomes. Upon light irradiation, PEG-MTPABZ-PyC-mediated photodynamic therapy induced significant cytotoxicity compared with the control group (P<0.05) and generated abundant intracellular ROS. CONCLUSIONS The novel photosensitizer PEG-MTPABZ-PyC demonstrates potent photodynamic cytotoxicity against gastric cancer cells, showing promising potential for further development in gastric cancer photodynamic therapy.
Humans ; Stomach Neoplasms/drug therapy* ; Photochemotherapy/methods* ; Photosensitizing Agents/pharmacology* ; Cell Line, Tumor ; Polyethylene Glycols/chemistry* ; Reactive Oxygen Species/metabolism* ; Mesoporphyrins/pharmacology*

Donors with a serum sodium concentration of >155 mmol/L are extended criteria donors for liver transplantation (LT). Elevated serum sodium of donors leads to an increased incidence of hepatic dysfunction in the early postoperative period of LT; however, the exact mechanism has not been reported. We constructed a Lewis rat model of 70% hepatic parenchymal area subjected to ischemia-reperfusion (I/R) with hypernatremia and a BRL-3A cell model of hypoxia-reoxygenation (H/R) with high-sodium (HS) culture medium precondition. To determine the degree of injury, biochemical analysis, histological analysis, and oxidative stress and apoptosis detection were performed. We applied specific inhibitors of the epithelial sodium channel (ENaC) and Na⁺/Ca²⁺ exchanger (NCX) in vivo and in vitro to verify their roles in injury. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels and the area of hepatic necrosis were significantly elevated in the HS+I/R group. Increased reactive oxygen species (ROS) production, myeloperoxidase (MPO)‍-positive cells, and aggravated cellular apoptosis were detected in the HS+I/R group. The HS+H/R group of BRL-3A cells showed significantly increased cellular apoptosis and ROS production compared to the H/R group. The application of amiloride (Amil), a specific inhibitor of ENaC, reduced ischemia-reperfusion injury (IRI) aggravated by HS both in vivo and in vitro, as evidenced by decreased serum transaminases, inflammatory cytokines, apoptosis, and oxidative stress. SN-6, a specific inhibitor of NCX, had a similar effect to Amil. In summary, hypernatremia aggravates hepatic IRI, which can be attenuated by pharmacological inhibition of ENaC or NCX.
Animals ; Reperfusion Injury/drug therapy* ; Hypernatremia/complications* ; Rats ; Liver/metabolism* ; Rats, Inbred Lew ; Male ; Apoptosis ; Sodium-Calcium Exchanger/antagonists & inhibitors* ; Reactive Oxygen Species/metabolism* ; Oxidative Stress ; Epithelial Sodium Channel Blockers/pharmacology* ; Epithelial Sodium Channels ; Cell Line ; Liver Transplantation

Periodontitis is a common oral disease caused by bacteria coupled with an excessive host immune response. Stem cell therapy can be a promising treatment strategy for periodontitis, but the relevant mechanism is complicated. This study aimed to explore the therapeutic potential of mitochondria from human embryonic stem cell-derived mesenchymal stem cells (hESC-MSCs) for the treatment of periodontitis. The gingival tissues of periodontitis patients are characterized by abnormal mitochondrial structure. Human gingival fibroblasts (HGFs) were exposed to 5 μg/mL lipopolysaccharide (LPS) for 24 h to establish a cell injury model. When treated with hESC-MSCs or mitochondria derived from hESC-MSCs, HGFs showed reduced expression of inflammatory genes, increased adenosine triphosphate (ATP) level, decreased reactive oxygen species (ROS) production, and enhanced mitochondrial function compared to the control. The average efficiency of isolated mitochondrial transfer by hESC-MSCs was determined to be 8.93%. Besides, a therapy of local mitochondrial injection in mice with LPS-induced periodontitis showed a reduction in inflammatory gene expression, as well as an increase in both the mitochondrial number and the aspect ratio in gingival tissues. In conclusion, our results indicate that mitochondria derived from hESC-MSCs can reduce the inflammatory response and improve mitochondrial function in HGFs, suggesting that the transfer of mitochondria between hESC-MSCs and HGFs serves as a potential mechanism underlying the therapeutic effect of stem cells.
Humans ; Gingiva/cytology* ; Fibroblasts/metabolism* ; Mitochondria/physiology* ; Mesenchymal Stem Cells/cytology* ; Animals ; Periodontitis/therapy* ; Mice ; Reactive Oxygen Species/metabolism* ; Inflammation ; Lipopolysaccharides ; Human Embryonic Stem Cells/cytology* ; Cells, Cultured ; Adenosine Triphosphate/metabolism* ; Male

BACKGROUND: Periodontitis is characterized by alveolar bone resorption, aggravated by osteoblast dysfunction, and associated with intracellular oxidative stress linked to the nuclear factor erythroid 2-related factor 2 (NRF2) level. We evaluated the molecular mechanism of periodontitis onset and development and the role of NRF2 in osteogenic differentiation. METHODS: Primary murine mandibular osteoblasts were extracted and exposed to Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) or other stimuli. Reactive oxygen species (ROS) and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining were used to detect intracellular oxidative stress. Alkaline phosphatase staining and alizarin red S staining were used to detect the osteogenic differentiation of osteoblasts. Immunofluorescence and western blotting were used to determine the changes in the mitogen-activated protein kinase (MAPK) pathway and related molecule activities. Immunofluorescence colocalization and co-immunoprecipitation were performed to examine the nuclear translocation of NRF2 and its interaction with dual-specific phosphatase 1 (DUSP1) in cells. RESULTS: Ligated tissue samples showed higher alveolar bone resorption rate and lower NRF2 level than healthy periodontal tissue samples. Pg-LPS increased intracellular oxidative stress levels and inhibited osteogenic differentiation, whereas changes in NRF2 expression were correlated with changes in the oxidative stress and osteogenesis rate. NRF2 promoted the dephosphorylation of the MAPK pathway by nuclear translocation and the upregulation of DUSP1 expression, thus enhancing the osteogenic differentiation capacity of mandibular osteoblasts. The interaction between NRF2 and DUSP1 was observed. CONCLUSIONS: NRF2 and its nuclear translocation can regulate the osteogenic differentiation of mandibular osteoblasts under Pg-LPS conditions by interacting with DUSP1 in a process linked to the MAPK pathway. These findings form the basis of periodontitis treatment.
Animals ; NF-E2-Related Factor 2/physiology* ; Lipopolysaccharides/pharmacology* ; Osteoblasts/drug effects* ; Mice ; Porphyromonas gingivalis/chemistry* ; Cell Differentiation ; Osteogenesis ; Dual Specificity Phosphatase 1/metabolism* ; Mandible/cytology* ; Reactive Oxygen Species/metabolism* ; Oxidative Stress ; Periodontitis/metabolism* ; Cells, Cultured ; Male ; Cell Nucleus/metabolism*

OBJECTIVES: To investigate the mechanism through which N-acetylneuraminic acid (Neu5Ac) exacerbates hypoxia/reoxygenation (H/R) injury in rat cardiomyocytes (H9C2 cells). METHODS: H9C2 cells were cultured in hypoxia and glucose deprivation for 8 h followed by reoxygenation for different durations to determine the optimal reoxygenation time. Under the optimal H/R protocol, the cells were treated with 0, 5, 10, 20, 30, 40, 50, and 60 mmol/L Neu5Ac during reoxygenation to explore the optimal drug concentration. The cells were then subjected to H/R injury followed by treatment with Neu5Ac, Fer-1 (a ferroptosis inhibitor), or both. The changes in SOD activity, intracellular Fe²⁺ and lipid ROS levels in the cells were evaluated, and the cellular expressions of Nrf2, GPX4, HO-1, FSP1, and xCT proteins were detected using Western blotting. RESULTS: Following hypoxia and glucose deprivation for 8 h, the cells with reoxygenation for 6 h, as compared with other time lengths of reoxygenation except for 9 h, showed the lowest expression levels of Nrf2, GPX4, HO-1, and FSP1 proteins (P<0.001). Neu5Ac treatment of dose-dependently decreased the viability of the cells with H/R injury with an IC₅₀ of 30.07 mmol/L. Reoxygenation for 3 h with normal glucose supplementation and a Neu5Ac concentration of 30 mmol/L were selected as the optimal conditions in the subsequent experiments. The results showed that Neu5Ac could significantly increase SOD activity, Fe²⁺ and lipid ROS levels and reduce Nrf2, GPX4, HO-1, and FSP1 protein expressions in H9C2 cells with H/R injury, but its effects were significantly attenuated by treatment with Fer-1. CONCLUSIONS Neu5Ac exacerbates ferroptosis of myocardial cells with H/R injury by inhibiting the Nrf2 axis to promote the production of ROS and lipid ROS.
Ferroptosis/drug effects* ; Myocytes, Cardiac/cytology* ; Animals ; NF-E2-Related Factor 2/metabolism* ; Rats ; N-Acetylneuraminic Acid/pharmacology* ; Cell Hypoxia ; Reactive Oxygen Species/metabolism* ; Cell Line ; Myocardial Reperfusion Injury/metabolism*

OBJECTIVES: To investigate the antioxidative mechanism of snake venom-derived protein C activator (PCA) in mitigating vascular endothelial cell injury. METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured in DMEM containing 1.0 g/L D-glucose and exposed to hypoxia (1% O₂) for 6 h followed by reoxygenation for 2 h to establish a cell model of oxygen-glucose deprivation/reoxygenation (OGD/R). The cell model was treated with 2 μg/mL PCA alone or in combination with 2-ME2 (a HIF-1α inhibitor) or DMOG (a HIF-1α stabilizer), and intracellular production of reactive oxygen species (ROS) and protein expression levels of HIF-1α, BNIP3, and Beclin-1 were detected using DCFH-DA fluorescence probe, flow cytometry, and Western blotting. The OGD/R cell model was transfected with a BNIP3-specific siRNA or a scrambled control sequence prior to PCA treatment, and the changes in protein expressions of HIF-1α, BNIP3 and Beclin-1 and intracellular ROS production were examined. RESULTS: In the OGD/R cell model, PCA treatment significantly upregulated HIF-1α, BNIP3 and Beclin-1 expressions and reduced ROS production. The effects of PCA were obviously attenuated by co-treatment with 2-ME2 but augmented by treatment with DMOG (a HIF-1α stabilizer). In the cell model with BNIP3 knockdown, PCA treatment increased BNIP3 expression and decreased ROS production without causing significant changes in HIF-1α expression. Compared with HUVECs with PCA treatment only, the cells with BNIP3 knockdown prior to PCA treatment showed significantly lower Beclin-1 expression and higher ROS levels. CONCLUSIONS Snake venom PCA alleviates OGD/R-induced endothelial cell injury by upregulating HIF-1α/BNIP3 signaling to suppress ROS generation, suggesting its potential as a therapeutic agent against oxidative stress in vascular pathologies.
Humans ; Reactive Oxygen Species/metabolism* ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Human Umbilical Vein Endothelial Cells/drug effects* ; Membrane Proteins/metabolism* ; Proto-Oncogene Proteins/metabolism* ; Up-Regulation ; Cell Hypoxia ; Cells, Cultured ; Snake Venoms/chemistry* ; Beclin-1

OBJECTIVES: To investigate the effect of downregulation of medium-chain acyl-coenzyme A dehydrogenase (ACADM) on invasion and migration of estrogen receptor-positive breast cancer cells and the underlying mechanism. METHODS: The Kaplan-Meier Plotter database was used to analyze the ACADM expression levels in breast cancer and normal tissues and their association with patient prognosis. Human breast cancer MCF-7 and T47D cell lines with lentivirus-mediated ACADM knockdown were established, and their in situ tumor formation and metastasis after tail vein injection were evaluated in nude mice. The MCF-7 and T47D cells with ACADM knockdown and their unmodified parental cells were examined with oil-red O staining assay, ROS assay, mitochondrial respiratory chain function assay before and after treatments with ROS scavenger, Elamipretide (a cardiolipin oxidation inhibitor) or SC79 (an AKT activator), and the changes in migration and invasion abilities of the treated cells were analyzed with Transwell invasion assay and Boyden chamber assay. Western blotting was used to detect protein expression levels of related signaling pathways in the treated cells. RESULTS: ACADM overexpression was associated with a significantly shorter overall survival of breast cancer patients. In MCF-7 and T47D cells, ACADM knockdown resulted in downregulation of N calnexin, vimentin, p-P13K and p-AKT proteins, increased levels of free fatty acids and reactive oxygen species, lowered activities of mitochondrial respiratory chain complex III and V, and reduced mitochondrial inner phospholipids. ACADM knockdown significantly decreased the invasive capacity of the cells, which were obviously reversed by treatment with ROS scavenger, Elamipretide, and SC79. CONCLUSIONS Down-regulation of ACADM inhibits migration and invasion ability of estrogen receptor-positive breast cancer cells by lowering lipotoxicity and impairing mitochondrial function through the ROS/PI3K/AKT pathway.
Humans ; Breast Neoplasms/metabolism* ; Female ; Mice, Nude ; Down-Regulation ; Neoplasm Invasiveness ; Animals ; Mice ; Receptors, Estrogen/metabolism* ; MCF-7 Cells ; Cell Movement ; Cell Line, Tumor ; Reactive Oxygen Species/metabolism* ; Acyl-CoA Dehydrogenase/genetics* ; Signal Transduction ; Neoplasm Metastasis ; Proto-Oncogene Proteins c-akt/metabolism*