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Background Increasing evidence suggests a double-faceted role of alpha-synuclein (α-syn) following infection by a variety of viruses, including SARS-CoV-2. Although α-syn accumulation is known to contribute to cell toxicity and the development and/or exacerbation of neuropathological manifestations, it is also a key to sustaining anti-viral innate immunity. Consistently with α-syn aggregation as a hallmark of Parkinson's disease, most studies investigating the biological function of α-syn focused on neural cells, while reports on the role of α-syn in periphery are limited, especially in SARS-CoV-2 infection. Results Results herein obtained by real time qPCR, immunofluorescence and western blot indicate that α-syn upregulation in peripheral cells occurs as a Type-I Interferon (IFN)-related response against SARS-CoV-2 infection. Noteworthy, this effect mostly involves α-syn multimers, and the dynamic α-syn multimer:monomer ratio. Administration of excess α-syn monomers promoted SARS-CoV-2 replication along with downregulation of IFN-Stimulated Genes (ISGs) in epithelial lung cells, which was associated with reduced α-syn multimers and α-syn multimer:monomer ratio. These effects were prevented by combined administration of IFN-β, which hindered virus replication and upregulated ISGs, meanwhile increasing both α-syn multimers and α-syn multimer:monomer ratio in the absence of cell toxicity. Finally, in endothelial cells displaying abortive SARS-CoV-2 replication, α-syn multimers, and multimer:monomer ratio were not reduced following exposure to the virus and exogenous α-syn, suggesting that only productive viral infection impairs α-syn multimerization and multimer:monomer equilibrium. Conclusions Our study provides novel insights into the biology of α-syn, showing that its dynamic conformations are implicated in the innate immune response against SARS-CoV-2 infection in peripheral cells. In particular, our results suggest that promotion of non-toxic α-syn multimers likely occurs as a Type-I IFN-related biological response which partakes in the suppression of viral replication. Further studies are needed to replicate our findings in neuronal cells as well as animal models, and to ascertain the nature of such α-syn conformations.
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Objective:To investigate the antagonistic effect and potential mechanism of specific AKT activator SC79 on the apoptosis of human retinal pigment epithelial (ARPE)-19 cells induced by high glucose in vitro. Methods:The ARPE-19 cells were cultured in high glucose medium (containing 30 mmol/L glucose) plus 5, 10 or 20 μg/ml SC79, respectively.After 6-, 12- and 24-hour culture, the optimal experimental concentration and timing were determined according to cell proliferation rate.Then ARPE-19 cells were divided into four groups, normal control group cultured in normal medium containing 5.6 mmol/L glucose for 48 hours, mannitol group cultured in medium containing 5.6 mmol/L glucose and 24.4 mmol/L mannitol for 48 hours, high glucose group cultured in high glucose medium for 48 hours, and high glucose+ SC79 group cultured in normal medium containing 10 μg/ml SC79 for 12 hours plus in high glucose medium for 36 hours.The proliferation rate of APRE-19 cells was detected by MTS assay.The apoptosis rate was measured by flow cytometry.The relative expression levels of phosphorylated protein kinase B (p-Akt), X-linked inhibitor of apoptosis protein (XIAP), caspase-9, caspase-3 and its active fragments (active-caspase-3) were assayed by Western blot.The ARPE-19 cells were divided into Neg-shRNA group, AKT shRNA group and blank control group and were treated with the corresponding transfection complex and serum-free medium.The AKT mRNA expression was detected by real-time PCR.The transfected ARPE-19 cells were divided into Neg-shRNA+ SC79 group and AKT shRNA+ SC79 group and were cultured according to the culturing method of high-glucose+ SC79 group.The apoptosis rate of the two groups was tested by flow cytometry.Results:Among different concentrations of SC79 and treatment times, the proliferation rate of cells treated with 10 μg/ml SC79 for 12 hours was the highest.The proliferation rate of ARPE-19 cells in high-glucose group was significantly lower than that in normal control group, mannitol group and high-glucose+ SC79 group, and the differences were statistically significant (all at P<0.01). The apoptosis rate of cells in the high-glucose group was (52.27±3.21)%, which was significantly higher than (3.90±0.71)% in normal control group and (20.70±3.62)% in high-glucose+ SC79 group (both at P<0.01). The relative expression levels of p-Akt, XIAP, caspase-9 and caspase-3 were significantly lower and the relative expression level of active-caspase-3 was significantly higher in high glucose group than those in normal control group and high-glucose+ SC79 group (all at P<0.05). The relative expression level of AKT mRNA in normal control group, Neg-shRNA group and AKT shRNA group was 0.60±0.07, 0.59±0.03 and 0.11±0.10, respectively, showing a statistically significant difference among the groups ( F=30.44, P<0.01). The apoptosis rate of cells in the AKT shRNA+ SC79 group was significantly higher than that in high-glucose+ SC79 group and Neg-shRNA+ SC79 group (both at P<0.001). Conclusions:SC79 can partially antagonize the apoptosis of ARPE-19 cells induced by high glucose, which is related to the activation of AKT/XIAP pathway and the inhibition of the caspase family.
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Objective: To investigate the role of surfactant associated protein-A (SP-A) in the development and progression of silicosis, and its mechanism. Methods: Homozygous and heterozygous mice of SP-A knockout of specific pathogen free (SPF) grade were selected for mating, and mice with SP-A-/- genotype were selected for subsequent experiments. SP-A wild-type (SP-A+/+) and SP-A-/- mice were divided into SP-A+/+ control group, SP-A-/- control group, SP-A+/+ silicosis group and SP-A-/- silicosis group with six mice in each group by random number table method. Mice in both silicosis groups were given 20.0 μL 250 g/L silica suspension by tracheal exposure, and mice in both control groups were injected with 0.9% sodium chloride solution at the same volume. On the 28th day after modeling, mice were sacrificed. Lung tissues were used for lung histopathology examination. The apoptosis of alveolar type Ⅱ epithelial cells of mice was detected by TUNEL method. The mRNA expression of B-lymphoblastoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), cysteinyl aspartate specific proteinase (Caspase)-3 and Caspase-9 in lung tissues of mice was detected by quantitative real-time polymerase chain reaction. Results: The histopathological result of mice showed that thickened alveolar septum, scattered silicon nodule and collagen fiber formation were observed in the mice lungs of SP-A+/+ silicosis group, and a large number of inflammatory cells were observed in silicosis nodule, after exposure to silica dust. SP-A-/- silicosis group resulted in a more severe pulmonary inflammation and interstitial fibrosis compared to SP-A+/+ silicosis group. The apoptosis of alveolar type Ⅱ epithelial cells and the mRNA relative expression levels of Bax, Caspase-3 and Caspase-9 in lung tissues of mice in each silicosis groups were increased compared with their control groups (all P<0.05). The above four indexes of mice in SP-A-/- silicosis group were higher than those in SP-A+/+ silicosis group (all P<0.05). There was no significant difference in the expression of Bcl-2 mRNA in lung tissues of these four groups (P>0.05). Conclusion: Knockout of SP-A can aggravate inflammation and pulmonary fibrosis in silicosis model mice, and promote apoptosis of alveolar type Ⅱ epithelial cells. The mechanism may be related to the Bcl-2/Bax/Caspase-3 signaling pathway which affects the apoptosis of mitochondrial pathway.
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OBJECTIVE@#To investigate the mechanisms underlying allergic conjunctivitis caused by conjunctival epithelial cell damage, neutrophil migration and neutrophil extracellular traps (NETs) formation induced by crude extracts of Dermatophagoides farinae mite (CDM).@*METHODS@#Human conjunctival epithelial cells were stimulated with 500, 1 000, 2 000, 4 000 ng/mL, and the expression levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and IL-8 were detected using quantitative real-time PCR (qPCR) assay and enzyme-linked immunosorbent assay (ELISA). The culture supernatant of human conjunctival epithelial cells was collected and co-cultured with neutrophils. Neutrophil migration was measured using Transwell migration assay, and the expression of NETs markers myeloperoxidase (MPO) and citrullinated histone H3 (CitH3) was quantified using immunofluorescence staining. Neutrophils were stimulated with phorbol 12-myristate 13-acetate (PMA), and then NETs were collected for treatment of human conjunctival epithelial cells. Cell apoptosis was detected using flow cytometry, and the levels of IL-6, TNF-α, IFN-γ and IL-8 were measured in the cell culture supernatant using ELISA.@*RESULTS@#Treatment with CDM at concentrations of 2 000 ng/mL and 4 000 ng/mL up-regulated IL-6, TNF-α, IFN-γ and IL-8 expression in human conjunctival epithelial cells. Following treatment with CDM at concentrations of 2 000 ng/mL and 4 000 ng/mL, the culture supernatant of human conjunctival epithelial cells promoted neutrophil migration and induced increases in the staining intensity of MPO and CitH3. In addition, increased NETs triggered the apoptosis of human conjunctival epithelial cells and IL-6, TNF-α, IFN-γ and IL-8 secretion in the culture supernatant of human conjunctival epithelial cells.@*CONCLUSIONS@#CDM induces human conjunctival epithelial cell damages, thereby promoting neutrophil migration and NETs formation, while the release of NETs further aggravates human conjunctival epithelial cell damages.
Subject(s)
Animals , Humans , Extracellular Traps , Neutrophils , Interleukin-8/metabolism , Dermatophagoides farinae , Interleukin-6/metabolism , Tumor Necrosis Factor-alpha/metabolism , Epithelial Cells , Interferon-gamma/metabolism , Tetradecanoylphorbol Acetate/pharmacologyABSTRACT
Inflammatory bowel disease (IBD) is a group of chronic idiopathic colorectal inflammatory diseases with a progressive and unpredictable course, including ulcerative colitis (UC) and Crohn's disease (CD). Abnormal intestinal inflammation and immune response contribute to the pathogenesis of IBD. Autophagy as an essential catabolic process in cells, has been demonstrated to have associations with a variety of inflammatory diseases including IBD. Here, we review the relationship between autophagy dysfunction and the process of IBD. The progress of several autophagy regulators for intestinal epithelial cells and macrophages is highlighted (inflammasome inhibitors, intestinal flora regulators, and other signal regulators) in the current studies on IBD.
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@#Ankylosis of primary molars is a kind of eruption abnormality of the teeth, where the periodontal membrane disappears, owing to a bony union between bone and root. Studies have shown that the common proportion of ankylosed primary molars is 1.3%~8.9% with an equal occurrence. In the primary dentition, the mandibular first primary molar is the most commonly affected tooth, while in the middle mixed dentition stage of development, the second primary molar is more affected. Its etiology may be related to genetics, signaling pathways of mineralization metabolism of local alveolar bone or cementum, cytokines secreted by epithelial rest cells of Malassez, and enhanced inflammatory reactions during physiological absorption of roots. Ankylosis of primary molars can be diagnosed by clinical symptoms and imaging and is classified as mild, moderate and severe according to the degree of infraocclusion. As it may cause a series of complications, such as occlusal disturbances, delayed exfoliation and incomplete alveolar process development, multidisciplinary treatment, including in the departments of pediatric dentistry, orthodontics, periodontics and prosthodontics, should be adopted, and long-term treatment is determined based on the patient's age, severity of infraocclusion, and presence of permanent teeth. This review summarizes the etiology, diagnosis, complications and treatment of ankylosed primary molars to provide a reference for the clinical diagnosis and treatment of decidual molar fixation.
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Objective To investigate the mechanisms underlying allergic conjunctivitis caused by conjunctival epithelial cell damage, neutrophil migration and neutrophil extracellular traps (NETs) formation induced by crude extracts of Dermatophagoides farinae mite (CDM). Methods Human conjunctival epithelial cells were stimulated with 500, 1 000, 2 000, 4 000 ng/mL, and the expression levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and IL-8 were detected using quantitative real-time PCR (qPCR) assay and enzyme-linked immunosorbent assay (ELISA). The culture supernatant of human conjunctival epithelial cells was collected and co-cultured with neutrophils. Neutrophil migration was measured using Transwell migration assay, and the expression of NETs markers myeloperoxidase (MPO) and citrullinated histone H3 (CitH3) was quantified using immunofluorescence staining. Neutrophils were stimulated with phorbol 12-myristate 13-acetate (PMA), and then NETs were collected for treatment of human conjunctival epithelial cells. Cell apoptosis was detected using flow cytometry, and the levels of IL-6, TNF-α, IFN-γ and IL-8 were measured in the cell culture supernatant using ELISA. Results Treatment with CDM at concentrations of 2 000 ng/mL and 4 000 ng/mL up-regulated IL-6, TNF-α, IFN-γ and IL-8 expression in human conjunctival epithelial cells. Following treatment with CDM at concentrations of 2 000 ng/mL and 4 000 ng/mL, the culture supernatant of human conjunctival epithelial cells promoted neutrophil migration and induced increases in the staining intensity of MPO and CitH3. In addition, increased NETs triggered the apoptosis of human conjunctival epithelial cells and IL-6, TNF-α, IFN-γ and IL-8 secretion in the culture supernatant of human conjunctival epithelial cells. Conclusions CDM induces human conjunctival epithelial cell damages, thereby promoting neutrophil migration and NETs formation, while the release of NETs further aggravates human conjunctival epithelial cell damages.
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Objective:To isolate and culture WU polyomavirus (WUPyV), and to analyze the genome-wide evolutionary patterns, homology and population dynamics.Methods:Real-time quantitative PCR was used to detect the nasopharyngeal aspirate samples of hospitalized children with respiratory tract infection in Beijing Friendship Hospital during 2020 to 2022. Primary human airway epithelial cells cultured at the air-liquid interface were used to isolate and culture WUPyV. Whole genome sequence of the isolated strain was obtained by Sanger sequencing. For phylogenetic and evolutionary dynamics analysis, the whole genome was compared with the published whole genome sequences in GenBank database.Results:The detection rate of WUPyV was 4.7% (31/659) during 2020 to 2022, and a clinical strain BJ0593 of WUPyV type Ⅲc was successfully isolated. The homology of the whole genome and gene fragments of WUPyV was high. The average evolutionary rate of VP2 gene was about 1.256×10 -4 substitution/site every year, and the population dynamics of WUPyV tended to be flat in the last decade. Conclusions:This study successfully isolated a clinical WUPyV type Ⅲ strain for the first time, which provided the basis for further investigation on the molecular evolution and pathogenicity of WUPyV.
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Objective:To compare gene expression profiles in normal human cervical epithelial cells (HcerEpic) before and after Chlamydia trachomatis ( Ct) infection. Methods:HcerEpic cells that were pretreated with DEAE-D were infected with Ct serotype E standard strain and then cultured for 44 h. Uninfected HcerEpic cells were used as the control group. Total RNA was extracted from the cells in each group and reverse transcribed to construct a cDNA library. Differences in gene expression profiles between the two groups were analyzed by high-throughput sequencing and the representative genes were selected for verification by qPCR. Results:A total of 23 997 genes were detected, including 125 differentially expressed genes. Among the 125 genes, 119 were up-regulated and six were down-regulated. GO analysis showed that the differentially expressed genes were enriched in several biological processes including defense response to virus, typeⅠinterferon signaling pathway and cellular responses to typeⅠinterferons. KEGG enrichment analysis showed the differentially expressed genes were mainly enriched in the pathways related to virus infections, such as influenza A virus, herpes simplex virus, EB virus and HPV, and NOD-like receptor pathway.Conclusions:There were significant differences in transcriptome profiles of HcerEpic cells before and after Ct infection. The differentially expressed genes were mainly enriched in the interferon pathway, which was closely related to the antiviral processes in cells. qPCR verified the differentially expressed genes and the genes closely related to the interferon pathway, such as ISG15, IFIT2, OASL and UBE2L6.
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Objective:To study the influence of circular RNA hsa_circZDHHC21_004 on the proliferation of human small intestinal epithelial cells HIEC-6 after 60Co γ-rays exposure. Methods:HIEC-6 cells were exposed to 60Co γ-rays at 0, 5, 10, and 15 Gy with a dose rate of 1 Gy/min. The expression level of hsa_circZDHHC21_004 in the irradiated HIEC-6 cell was detected. Hsa_circZDHHC21_004 was knocked-down to investigate the influences of hsa_circZDHHC21_004 on the proliferation of irradiated HIEC-6 cells by CCK-8 assay and colony formation assay. Results:The expression level of hsa_circZDHHC21_004 in HIEC-6 cells was upregulated by (1.00±0.24), (1.34±0.28), (1.85±0.31), and (2.80±0.64) times of control after 0, 5, 10, and 15 Gy irradiation, respectively and there were significant difference between 10 or 15 Gy group and 0 Gy group ( F=10.86, P=0.008). Knockdown of hsa_circZDHHC21_004 significantly increased the proliferation rate of HIEC-6 cells at 24, 48, and 72 h after 10 Gy irradiation compared with non-irradiated control ( t=-6.25, -5.83, -7.75, P < 0.001). Under 2 and 5 Gy irradiation, the clone formation rates of the hsa_circZDHHC21_004 knockdown cells were significantly higher than those of the control ( t=-7.45, -8.83, P<0.01). Conclusions:Hsa_circZDHHC21_004 is increased after irradiation and influenced the proliferation of irradiated HIEC-6 cells.
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Objective:To observe the expression of deleted in malignant brain tumor protein 1 (DMBT1) in rat acute respiratory distress syndrome (ARDS) model induced by sepsis and its relationship with ARDS related biomarkers.Methods:Forty-eight healthy male rats were randomly divided into sham operation group (Sham group) and ARDS model group, and the rats in each group were further divided into three subgroups at 6, 12 and 24 hours after operation, with 8 rats in each subgroup. The rats in the Sham group were exposed to the cecum only, and sepsis induced ARDS model was reproduced by cecal ligation and puncture (CLP) in the ARDS model group. The general performance was observed at 6, 12, 24 hours after operation. Abdominal aortic blood of rats was collected, and the levels of DMBT1, surfactant-associated protein D (SP-D), vascular endothelial growth factor (VEGF), interleukins (IL-6, IL-10) in serum were determined by enzyme-linked immunosorbent assay (ELISA). The lung tissues were collected, and the lung wet/dry weight (W/D) ratio was determined. The lung tissue pathological changes were observed under light microscope after hematoxylin-eosin (HE) staining, and the lung tissue injury score was evaluated. The expression of DMBT1 protein in lung tissue was determined by Western blotting. The relationship between the serum DMBT1 and SP-D, VEGF, IL-6, IL-10, lung tissue injury score were analyzed by Pearson correlation analysis.Results:Rats in the ARDS model group showed obvious pathological manifestations after operation. The alveolar structure destruction, inflammatory cell infiltration, and alveolar hemorrhage were observed under microscope. Compared with the Sham group, the lung tissue injury score and the lung W/D ratio at 12 hours after operation in the ARDS model group were significantly increased (lung tissue injury score: 3.35±0.13 vs. 1.16±0.07, lung W/D ratio: 5.36±0.44 vs. 4.38±0.35, both P < 0.05), and pulmonary edema was present, which suggested that the ARDS model caused by CLP was successfully reproduced. The results of ELISA and Western blotting showed that the levels of serum DMBT1, SP-D, VEGF and IL-6 in the ARDS model group increased gradually with time, while the level of IL-10 increased first and then decreased. Compared with the Sham group, the levels of DMBT1 in serum and the expressions of DMBT1 protein in lung tissue in the ARDS model group were significantly increased from 6 hours after operation [serum (ng/L) : 231.96±19.17 vs. 187.44±10.19, lung tissue (DMBT1/β-actin): 2.05±0.19 vs. 0.93±0.25, both P < 0.05], and the levels of SP-D, VEGF, IL-6 and IL-10 in serum were significantly increased from 12 hours after operation [SP-D (ng/L): 73.35±8.05 vs. 43.28±5.77, VEGF (ng/L): 89.85±8.47 vs. 43.19±5.11, IL-6 (ng/L): 36.01±2.48 vs. 17.49±1.77, IL-10 (ng/L): 84.55±8.41 vs. 39.83±5.02, all P < 0.05]. Pearson correlation analysis showed that serum DMBT1 was positively correlated with serum SP-D, VEGF, IL-6, IL-10 and lung injury score at 12 hours and 24 hours in the ARDS model group (12 hours: r values were 0.946, 0.942, 0.931, 0.936, 0.748, respectively; 24 hours: r values were 0.892, 0.945, 0.951, 0.918, 0.973, respectively; all P < 0.05). Conclusion:DMBT1 is a novel early biomarker of ARDS by affecting alveolar epithelial cell, alveolar capillary permeability and inflammatory response.
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Objective:To investigate whether microRNA-21-5p (miR-21-5p) alleviates hyperoxia-induced acute lung injury (HALI) through activating the phosphatidylinositol 3 kinase/serine-threonine protein kinase (PI3K/Akt) signaling pathway by regulating apoptosis of type Ⅱ alveolar epithelial cell (AECⅡ).Methods:Seventy-two male Sprague-Dawley (SD) rats were divided into normozone-controlled group, HALI group, PI3K/Akt signaling pathway inhibitor LY294002+HALI group (LY+HALI group), miR-21-5p overexpression+LY294002+HALI group (miR-21-5p+LY+HALI group), miR-21-5p overexpression+HALI group (miR-21-5p+HALI group), and dimethyl sulfoxide (DMSO)+HALI group by random number table method with 12 rats in each group. Animal models of HALI were prepared using 95% concentrations of oxygen. The animals in the normozone-controlled group were fed normally under normoxia. Transfection of lung tissue by miR-21-5p adeno-associated viral vector AAV6-miR-21-5p was performed by instillation of 200 μL titer (1×10 12 TU/mL) through a tracheal catheter 3 weeks prior to modeling. DMSO and LY294002 were administered via the tail vein at 0.3 mg/kg 1 hour before modeling. After 48 hours of modeling, carotid artery blood was collected to detect oxygenation index (OI) and respiratory index (RI), and real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect miR-21-5p expression. Lung tissue was collected, and the levels of inflammatory factors including tumor necrosis factor-α (TNF-α) and interleukins (IL-6, IL-1β) were measured by enzyme-linked immunosorbent assay (ELISA), and the ratio of pulmonary wet/dry weight (W/D) was determined, and the pathological changes of lung histopathology were observed under the light microscopy after hematoxylin-eosin (HE) staining. Each group was purified AECⅡ cells from 6 rats, the apoptosis rate was detected by flow cytometry, and the expression levels of phosphatase and tensin homologous gene (PTEN), and proteins from the PI3K/Akt signaling pathway were detected by Western blotting. Results:Compared with the normozone-controlled group, alveolar septal thickening and massive inflammatory cell infiltration were found after hyperoxia exposure, RI, inflammatory factors, lung W/D ratio, pathological score, AECⅡ cells early apoptosis rate, PTEN protein expression and phosphorylation level of Akt were increased, while OI and miR-21-5p expression were decreased, indicating the successful preparation of the model. After pretreatment, LY294002 could aggravate the pathological injury of lung tissue in HALI rats, RI, inflammatory factors and lung W/D ratio were further increased, and OI was further reduced compared with HALI group. At the same time, it could promote the AECⅡ cell apoptosis, further up-regulate the expression of PTEN, and reduce the phosphorylation of Akt. However, miR-21-5p pretreatment could negatively regulate PTEN, activate PI3K/Akt signal pathway, inhibit AECⅡ cell apoptosis, and reduce HALI, which was shown by the decreased level of inflammatory factors in miR-21-5p+LY+HALI group compared with LY+HALI group [TNF-α (μg/L): 100.33±3.48 vs. 116.55±2.53, IL-6 (ng/L): 141.06±3.70 vs. 161.31±3.59, IL-1β (μg/L): 90.82±3.69 vs. 112.23±2.87, all P < 0.05], RI, lung injury pathology score, lung W/D ratio, and AECⅡ cell early apoptosis rate were significantly decreased [RI: 0.81±0.02 vs. 1.05±0.07, pathology score: 0.304±0.008 vs. 0.359±0.007, lung W/D ratio: 5.29±0.03 vs. 5.52±0.08, apoptosis rate: (27.20±2.34)% vs. (34.17±1.49)%, all P < 0.05], OI and expressions of miR-21-5p were significantly increased [OI (mmHg, 1 mmHg≈0.133 kPa): 266.71±2.75 vs. 230.12±4.04, miR-21-5p (2 -ΔΔCt): 2.21±0.13 vs. 0.33±0.03, both P < 0.05], and PTEN protein expression in AECⅡ cell was significantly reduced (PTEN/GAPDH: 0.50±0.06 vs. 0.93±0.06, P < 0.05), and phosphorylation level of Akt was significantly increased [phosphorylated Akt (p-Akt) protein (p-Akt/GAPDH): 0.86±0.05 vs. 0.56±0.06, P < 0.05]. Conclusion:miR-21-5p attenuates HALI by inhibiting AECⅡ cell apoptosis, possibly through negative regulation of PTEN to activate PI3K/Akt signaling pathway.
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ABSTRACT Purpose: To systematically examine the dynamic changes and time sequence in corneal epithelial cell apoptosis after excessive ultraviolet B irradiation. Methods: Ultraviolet B (144 mJ/cm2) was used to irradiate rat corneal epithelial cells for 2 h. Cell morphology was observed on differential interference contrast microscopy, and the numbers of the different kinds of apoptotic cells were counted using the ImageJ software. Cell viability was measured with the 3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2-H-tetrazolium bromide method. Cell apoptotic rate and loss of mitochondrial membrane potential were detected using flow cytometric analyses. The expression levels of 3 apoptotic genes were measured with real-time quantitative polymerase chain reaction at different time points within 0-24 h after irradiation. Results: After 144-mJ/cm2 ultraviolet B irradiation for 2 h, the expression levels of caspase-8 and Bax were highest at 0 h; furthermore, the mitochondrial membrane potential decreased at 0 h and remained constant for 6 h in a subsequent culture. At 6 h, caspase-3 was activated. The decrease in cell viability and increase in apoptotic rate peaked at 6 h. The caspase-3 expression level decreased within 12-24 h, which led to a decline in apoptotic rate and change in apoptotic stage. Conclusions: The corneal epithelial cells exhibited rapid apoptosis after ultraviolet B irradiation, which was associated with both extrinsic and intrinsic pathways.
RESUMO Objetivos: Explorar sistematicamente as mudanças dinâmicas e a sequência temporal no processo de apoptose de células epiteliais corneanas após excesso de irradiação com ultravioleta B. Métodos: A radiação ultravioleta B (144 mJ/cm2) foi utilizada para irradiar células epiteliais da córnea de rato durante 2h. A morfologia celular foi observada por meio de microscópio de contraste de interferência diferencial, e os números de diferentes tipos de células apoptóticas foram contados e registrados pelo software ImageJ. A viabilidade celular foi medida pelo método brometo de 3- (4, 5-dimetil-2-tiazolil) -2, 5-difenil-2-H-tetrazólio. A taxa apoptótica celular e a perda do potencial da membrana mitocondrial foram detectadas por meio de análises citométricas de fluxo. Os níveis de expressão de três genes apoptóticos foram medidos por reação em cadeia da polimerase quantitativa em tempo real em diferentes momentos dentro de 0-24 h após a irradiação. Resultados: Após 144 mJ/cm2 de irradiação com ultravioleta B por 2h, os níveis de expressão de caspase-8 e Bax foram maiores em 0h; o potencial da membrana mitocondrial diminuiu a 0h e permaneceu constante por 6h na cultura subsequente. Às 6h, a caspase-3 foi ativada. A diminuição da viabilidade celular e o aumento da taxa apoptótica atingiu o pico em 6h. A expressão de caspase-3 diminuiu dentro de 12 - 24 h, levando a um declínio na taxa apoptótica e alteração no estágio apoptótico. Conclusões: As células epiteliais da córnea apresentaram uma apoptose rápida após excesso de irradiação com ultravioleta B, e esse processo foi associado tanto à via extrínseca como à via intrínseca.
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Objective:To explore the mechanism of Bufei Yishen formula (BYF) on attenuating cigarette smoke extract (CSE)-induced airway mucus hypersecretion by regulating Notch signaling pathway.Methods:The human airway epithelial cell 16HBE was cultured in vitro, and the cells in logarithmic growth phase were used for the experiments. ① Intervention condition screening experiment: the 16HBE cells were grouped, methylthiazolyldiphenyl-tetrazolium (MTT) method and enzyme-linked immunosorbent assay (ELISA) were used to detect the effects of different concentrations of CSE (2.5%, 5%, 10%, 20%, 40%), different concentrations of BYF drug-containing serum (5%, 10%, 20%, 40%), and different concentrations of Notch signal pathway blocker DAPT (5, 10, 20, 40 μmol/L) on cell activity and secretion of mucin 5AC (MUC5AC) levels. In addition, a blank control group was set up to screen out the best conditions for preparing CSE-induced cell mucus hypersecretion model and BYF and DAPT intervention. ② Intervention experiment: the 16HBE cells were divided into four groups. The blank control group was not given any treatment; the 16HBE cells were induced by 10% CSE for 24 hours to prepare mucus hypersecretion model in the CSE model group; the cells in the CSE+BYF group and CSE+DAPT group were given 10% BYF or 20 μmol/L DAPT, respectively, for intervention at the same time for 24 hours. Real-time fluorescent quantitative polymerase chain reaction (qPCR) was used to detect the mRNA expressions of MUC5AC, Notch3 and hairy and enhancer of split 1 (HES1) in the cells. Western blotting was used to detect the protein expressions of Notch3 and HES1 in the cells. Results:① Results of the screening experiment of intervention conditions: compared with the blank control group, 10% CSE induction for 24 hours was the best condition for establishing cell mucus hypersecretion model that neither affected cell viability nor increased the secretion of MUC5AC; while 10% BYF and 20 μmol/L DAPT was the optimal intervention condition. ② Intervention experiment results: compared with the blank control group, the mRNA expressions of MUC5AC, Notch3, and HES1 and the protein expressions of Notch3 and HES1 in the CSE model group were significantly increased, indicating that CSE activated Notch3 and HES1 signal activation and induced 16HBE cells to secrete mucus protein. Compared with the CSE model group, BYF and DAPT could significantly down-regulate the mRNA and protein expressions of MUC5AC, Notch3, and HES1 in cells [MUC5AC mRNA (2 -ΔΔCT): 1.03±0.13, 0.96±0.05 vs. 1.35±0.07, Notch3 mRNA (2 -ΔΔCT): 1.10±0.14, 1.10±0.02 vs. 1.31±0.15, HES1 mRNA (2 -ΔΔCT): 1.26±0.10, 1.14±0.15 vs. 1.45±0.08, Notch3 protein (Notch3/GAPDH): 0.10±0.03, 0.16±0.03 vs. 0.31±0.09, HES1 protein (HES1/GAPDH): 0.37±0.06, 0.34±0.08 vs. 0.50±0.05, all P < 0.05]. Conclusion:The mechanism of BYF attenuating mucus hypersecretion of 16HBE cells induced by CSE was associated with the inhibition of Notch signaling pathway activation.
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Objective:To explore the effect of Toll-like receptor 9 (TLR9) signaling pathway activation on the transcriptome in the renal tubular cells.Methods:Mouse primary renal tubular epithelial cells were extracted and cultured. When the degree of cell fusion reached 80%, they were divided into two groups, which were added with 10 μL phosphate buffered saline (PBS, PBS control group) and TLR9 activator cytosine phosphate guanidine oligodeoxynucleotide (CpG-ODN) with a final concentration of 5 μmol/L (CpG-ODN treatment group). The RNA sequencing was performed on the Illumina platform after extraction. DEGseq software was used to analyze the differential expression of genes between the two groups. Goatools and KOBAS online software were used to analyze the differential genes involved signal pathways. Homer software was used to predict transcription factors.Results:Compared with the PBS control group, there were a total of 584 differentially expressed genes in the CpG-ODN treatment group, of which 102 were up-regulated and 482 were down-regulated. The most significantly enriched gene ontology (GO) terms of differentially expressed genes included response to interferon-β, defense response to virus and other inflammatory pathway. The most significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways included 2'-5'-oligoadenylate synthase activity, regulation of ribonuclease activity, negative regulation of virus life cycle, cellular response to interferon-βand defense response to protozoan. The results of transcription factor prediction showed that interferon regulatory factor 3 (IRF3) was the most significantly enriched transcription factor in the promoter sequence of differential genes; the most significant transcription factor downstream of TLR9 was IRF3, and other predicted transcription factors such as transcription factor 21 (TCF21), zinc finger protein 135 (ZNF135), and PR domain containing 4 (PRDM4) might be new candidates for TLR9 signaling pathway.Conclusion:CpG-ODN activates TLR9 signaling pathway, and primary renal tubular epithelial cells can directly respond to CpG-ODN stimulation and undergo transcriptome changes, which provides a basis for further research on the molecular mechanism of TLR9 pathway in sepsis induced acute kidney injury.
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Objective:To study the effects of endothelial progenitor cells (EPC)-derived exosomes on hyperoxia-induced injury in type Ⅱ alveolar epithelial cell (AECⅡ) in neonatal rats.Methods:EPCs of rats were cultured and exosomes were collected using Total Exosome Isolation kit. Primary cultured AECⅡof neonatal rats were randomly assigned into three groups: the control group, the hyperoxia group and the exosome group. The control group was cultured in room air with 5%CO 2, the hyperoxia group was cultured in 95%O 2 with 5%CO 2 and the exosome group was cultured with 0.1 mg/ml EPC-derived exosomes in 95%O 2 with 5%CO 2. Cell viability was detected using cell counting kit-8 (CCK-8) and apoptosis was detected using flow cytometry on d2, d4, and d6. Results:EPC-derived exosomes isolated from EPC culture supernatant were confirmed morphologically using transmission electron microscopy. After co-incubation of Dil-labeled EPC-derived exosomes with AEC Ⅱ for 24 h, Dil fluorescence was detected in the cytoplasm of AEC Ⅱ, indicating exosomes were uptaken by AEC Ⅱ. Compared with the control group, hyperoxia decreased cell viability and increased apoptosis of AEC Ⅱ and the injury was aggravated with the prolongation of hyperoxia duration ( P<0.001). Cell injury in the exosome group was milder than the hyperoxia group ( P<0.001). Compared with the control group, cell viability on d4 and d6 of hyperoxia was lower ( P=0.029 and 0.005 respectively) and cell apoptosis at d6 of hyperoxia was higher in the exosome group ( P=0.007). Conclusions:EPC-derived exosomes may partially attenuate hyperoxia-induced cell injury in neonatal rat AEC Ⅱ.
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Objective:To investigate whether polyethylene glycol hydrogel films (PHFs) can be used as a carrier for the expansion of corneal epithelial cells (CECs) in vitro and whether PHFs can be used in the treatment of limbal stem cell deficiency (LSCD). Methods:Sebacoyl chloride, dihydroxyl PCL and glycerol ethoxylate were used to synthesize PHFs.The thickness, transmittance and mechanical tensile properties of PHFs were measured.Four clean-grade New Zealand white rabbits were selected to culture primary limbal epithelial cells.The expression of keratin marker AE1/AE3 and stem cell marker p63 in the cultured cells were observed under a fluorescence microscope.The cells were divided into negative control group cultured with common cell culture solution, positive control group cultured with cell culture solution containing 100 μmol/L H 2O 2, and PHFs+ CECs group lined with PHFs cultured with common cell culture solution for 24 hours.The proliferation and apoptosis of cells in the three groups were observed by MTT and TUNEL staining, respectively.Fifteen clean-grade New Zealand white rabbits were divided into control group, PHFs group and PHFs+ CECs group by random number table method, with 5 rabbits in each group.LSCD model was constructed in the three groups.The control group was not given any treatment after modeling.In PHFs group, empty PHFs were placed on the corneal surface of rabbits.In PHFs+ CECs group, tissue-engineered grafts constructed with CECs after passage implanted on PHFs were placed on the corneal surface of rabbits.The corneal defect area of rabbits was detected and scored by fluorescein sodium staining.The histological characteristics of rabbits corneal epithelium was observed by hematoxylin-eosin staining.The use and care of animals complied with Guide for the Care and Use of Laboratory Animals by the U. S.National Research Council.The experimental protocol was approved by the Research and Clinical Trial Ethics Committee of The First Affiliated Hospital of Harbin Medical University (No.2021006). Results:The synthetic PHFs were with a thickness ≤150 μm, a tensile strength about 6 MPa, and a transmittance over than 99% in the range of 400-700 nm.Most of the cells from primary culture of limbal tissue were positive for AE1/AE3 and p63.MTT test results showed that the A490 value of PHFs+ CECs group, negative control group and positive control group was 0.59±0.01, 0.65±0.07 and 0.06±0.04, respectively, showing a statistically significant overall difference ( F=12.25, P<0.05). The A490 values of PHFs+ CECs group and negative control group were significantly higher than that of positive control group, and the differences were statistically significant (both at P<0.05). TUNEL test results showed that there was a significant difference in the TUNEL-positive cell rate among the three groups ( F=13.45, P<0.05), and the rates of TUNEL-positive cells in PHFs+ CECs group and negative control group were significantly lower than that in positive control group (both at P<0.05). Fluorescein sodium staining results showed that with the extension of postoperative period, the corneal fluorescein sodium staining score of the three groups decreased, which decreased successively in control group, PHFs group and PHFs+ CECs group.Hematoxylin-eosin staining showed fewer irregularly shaped corneal epithelial cells in the control group, and sparse single layer of corneal epithelial cells in some areas of the PHFs group.In PHFs+ CECs group, the corneal epithelium coverage was the largest, and the cell layers increased to 3-5, and the cells were with regular morphology and in close arrangement. Conclusions:PHFs have enough toughness, high transmittance and can expand corneal epithelium in vitro.PHFs are suitable for corneal epithelial transplantation and can promote the repair of corneal epithelium in rabbit model of LSCD.
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It was found that intestinal flora could directly regulate mitochondria of intestinal epithelial cells or indirectly through the nucleus. This effect is associated with the flora metabolites such as short-chain fatty acids (SCFAs), hydrogen sulfide (H2S) and nitric oxide (NO). These metabolites are involved in mitochondria-related energy metabolic processes and the production of mitochondrial reactive oxygen species (mtROS), and even in the immune response of the whole organism. Numerous studies have also shown that intestinal flora metabolites and mitochondria have become a hot spot for research on the mechanism of action of traditional Chinese medicine, but the research on the mechanism of association between them is not yet in-depth. In this review, we summarize the mechanism of mitochondrial regulation of intestinal epithelial cells by intestinal flora metabolites and herbal interventions to provide a theoretical basis for targeting intestinal microbes and mitochondria to regulate body metabolism and health.
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Fine particulate matter (PM2.5) has attracted more and more attention in the field of environmental pollution and public health. Previous studies have found that PM2.5 can be inhaled and deposit in the airway and alveoli, and even spread to the whole-body tissues and organs through blood, resulting in various toxic effects. The malignant transformation of lung epithelial cells associated with long-term exposure to PM2.5 may play an important role in the occurrence and development of lung cancer. This paper reviewed recent studies on the mechanisms of malignant transformation of lung epithelial cells associated with PM2.5 exposure, and discussed the main biological mechanisms, including epigenetics, tumor microenvironment, and other biological pathways. Besides, the potential research directions of malignant transformation of lung epithelial cells associated with PM2.5 exposure were proposed. This work aims to provide a scientific basis and reference for public health management and air quality assessment.
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Objective@#Fine particulate matter (PM 2.5) is an air pollutant that has become of great concern in recent years. Numerous studies have found that PM 2.5 may contribute to lung cancer, but the pathogenesis has not yet been fully elucidated. In this study, we explored the roles of exosomes from bronchial epithelial cells in PM 2.5-promoted lung cancer metastasis.@*Methods@#Exosomes were isolated from cell supernatants. An animal model of lung metastasis (established by tail vein injection of A549-luc) and in vitro studies with lung cancer cell lines were used to investigate the effects of exosomes derived from PM 2.5-treated human bronchial epithelial cells (PHBE-exo).@*Results@#The animal experiments revealed that PHBE-exo-treated mice showed stronger luciferase activity and a larger relative metastatic region in the lungs, thus indicating that PHBE-exo promoted the metastatic potential of lung cancer. Additionally, PHBE-exo promoted the migration, invasion and epithelial-to-mesenchymal transition of lung cancer cells, in a manner mediated by activation of c-Jun N-terminal kinase.@*Conclusion@#These results implied that PM 2.5 may promote the development of lung cancer through exosomes derived from bronchial epithelial cells, thus providing a potential interventional target for lung cancer. These findings broadened our understanding of cancer-promoting mechanisms of environmental pollutants.