Objective To assess the feasibility of heterogeneous acellular dermal matrix(ADM)seeded with adipose derived stem cells(ADSC)for urethroplasty in a rabbit model.Methods ADSC were isolated from a rabbit and expanded in vitro,then identified by flow cytometry.We seeded ADSC onto the ADM and made it into tissue-engineered urethra.12 male rabbits were removed 1 cm urethra and divided into experiment group and control group.There were 6 rabbits in each group.Reconstructed urethra with tissueengineered urethra was used in experiment group,while unseeded ADM were used in control group.Urethrography was performed at 6 months after surgery.The animals were scarified at 3 and 6 months after surgery and the repaired urethra were harvested.H&E staining and immunohistochemical staining were performed with cytokeratin AE1/AE3 and smooth muscle desmin makers.Results The morphology of isolated ADSC was with long spindle cross-links,and had multicentral growth.Flow cytometry showed that the ADSC expressed CD166,CD105,CD90 and CD44,but not expressed CD45 and CD13.The cells could growth well on the ADM and showed good biocompatibility with it.All animals could void normally,urethrography showed there was no significant stenosis.3 months after surgery,the experiment group appeared regenerated smooth muscle but not in the control group,both groups did not regenerate urothelium.At 6 months urothelium and smooth muscle cells could be observed in the experiment group,but only the smooth muscle was evident in the control group.Conclusions By applying tissue engineering methods,we can seed the ADSC onto the heterogeneous ADM and make it into tissue-engineered urethra,which can help improve the reconstructive effect of urethra.

Objective To assess the effects of MRI-positive and interictal epileptic charges(IEDs) dominance on the memory of the patients with drug-resistant medial temporal lobe epilepsy (MTLE). Methods Fifty right-handed patients(age ranging from 16 to 60 years old)diagnosed as drug-resistant MTLE in our hospital with normal intelligence between September 2006 and April 2007 were investigated. All patients were classified as left MRI-positive(MRI(+)),right MRI(+),MRI(-),bilateral MR[ (+)by high-quality MR[protocol.The EEG was defined as dominant IEDs if≥75%independent IEDs was confined to one temporal lobe in all EEG recordings.Clinical memory scale was administered as memory assessment of MTLE.ANOVA and non-parametric statistics were used to analyze the data in SPSS 12.0. Results The distribution of age,sex,education,occupation,living condition,course,seizure and treat among left MRI(+),right MRI(+),MRI(-),bilateral MRI(+)groups was similar.All scores in the patients with MTLE was significantly lower than normal(P＜0.05).Right MRI(+)MTLE patients had deftcits in nonsense graphics recognition(9.42±7.46)compared to left MRI(+)and MRI(-) groups((16.26±4.43)and(18.26±5.49),F=4.281,P＜0.05).Among MRI(-)patients,left IEDs,right IEDs and bilateral IEDs groups displayed not significantly different impairment in memory. Conclusion Right MRI(+)MTLE has more severe impairment in non-verbal memory,and nonsense graphics recognition can be used to detect the deficit.

Objective To characterize the finals mispronunciation in Chinese-speaking children with functional articulation disorder (FAD),in order to promote the standardized diagnosis.Method A retrospective study was conducted.From January to December 2013,90 FAD children,diagnosed by Dysarthria Rating Scale and Mandarin Finals scale,were included in this study.Among them,22 were found to have finals mispronunciation;the average age was (6.56 ± 0.26) years.According to the finals classification,six different finals (simple finals,front vowel compound finals,central vowel compound finals,back vowel compound finals,anterior nasal finals,and posterior nasal finals) were defined;the produced sound samples of those subjects were analyzed.Result In all these children,22 of 90 (24％)were found having finals mispronunciation,the occurring rates of which with omission and substitution errors were:3％ (4/132) for simple finals,30％ (26/88) for front vowel compound finals,26％ (23/88) for central vowel compound finals,7％ (8/110) for back vowel compound finals,73％ (128/176) for anterior nasal finals and 73％ (112/154) for posterior nasal finals,respectively.In omission and substitution errors,the ratios of the finals above were 50％ (150/301),3％ (10/301),5％ (14/301),36％ (107/301),2％ (5/301) and 5％ (15/301),respectively.The most frequently occurred mispronunciation were omission,substitution and distortion,with rates of 37％ (273/748),4％ (28/748) and 8％ (61/748),respectively.Conclusion The FAD children have remarkable mispronunciation of finals.Omission is the main error.The nasal finals are the most commonly involved,followed by front vowel and central vowel compound finals.The simple finals and the back vowel compound finals are most commonly produced in omission and substitution.These finals production features should be considered when making and implementing rehabilitation programs.

OBJECTIVE: To observe the changes of peripheral blood neutrophil apoptosis rate and the effect of p38 mitogen-activated protein kinase (p38MAPK) inhibitor on peripheral blood neutrophil apoptosis in severely burned patients. METHODS: Severe burn patients [burn area ≥ 30% total body surface area (TBSA), deep II to III degrees, burn index ≥ 20%, age > 20 years old] admitted to the department of burn and plastic surgery of Affiliated Suzhou Hospital of Nanjing Medical University from January to May in 2019 and health examination volunteers during the same period were enrolled. The peripheral blood neutrophils were isolated by Ficoll gradient centrifugation. The neutrophils of severely burned patients were divided into burn group and p38MAPK inhibitor SB203580 group (after 30 minutes incubation at room temperature and 24 hours incubation in incubator); the neutrophils of healthy volunteers were used as control group. The apoptosis of neutrophils was detected by flow cytometry; the level of reactive oxygen species (ROS) in neutrophils was detected by fluorescence probe; the expression of p38MAPK protein and its phosphorylation (p-p38MAPK) level were detected by Western Blot. RESULTS: Compared with the control group, the apoptosis rate of neutrophils in burn group was significantly decreased [(37.42±3.14)% vs. (50.20±9.87)%, P < 0.05], and the ROS production level in neutrophils was significantly increased (fluorescence intensity: 83.28±0.29 vs. 75.23±0.34, P < 0.05). The apoptosis rate of neutrophils in SB203580 group was further lower than that in burn group [(25.51±1.56)% vs. (37.42±3.14)%, P < 0.05], and the level of ROS production was further higher than that in burn group (fluorescence intensity: 95.56±3.67 vs. 83.28±0.29, P < 0.05). There was no significant difference in the protein expression of p38MAPK among the three groups. The p-p38MAPK protein level in burn group was significantly lower than that in control group (p-p38MAPK/p38MAPK: 0.45±0.06 vs. 0.91±0.09, P < 0.05), while the expression level of p-p38MAPK in SB203580 group was further lower than that in burn group (p-p38MAPK/p38MAPK: 0.22±0.04 vs. 0.45±0.06, P < 0.05). CONCLUSIONS Peripheral blood neutrophil apoptosis delayed and ROS production were increased in severely burned patients. The mechanism may be related to p38MAPK pathway inhibitor.
Apoptosis ; Burns ; Humans ; Neutrophils ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases

Objective:To investigate the effect of neutrophils on T lymphocyte function in septic mice and the role of CD80/cytotoxic T lymphocyte antigen-4 (CTLA-4) signaling pathway in this modulated effects.Methods:① In vivo experiment: 6-8 weeks old male C57BL/6 mice were divided into sham operation group (Sham group, n = 20), Sham+CTLA-4 antibody treatment group (Sham+aCTLA-4 group, n = 20), cecal ligation and perforation (CLP) induced sepsis model group (CLP group, n = 30) and CLP+CTLA-4 antibody treatment group (CLP+aCTLA-4 group, n = 30) according to the random number table. CLP was used to reproduce mouse sepsis model. The mice in the Sham group were treated identically but their cecums were neither punctured nor ligated. In CTLA-4 antibody treatment groups, 50 μg CTLA-4 antibody was injected intraperitoneally 6 hours and 24 hours after the operation. Forty-eight hours after operation, 6 mice in Sham group and Sham+aCTLA-4 group, 14 mice in CLP group and CLP+aCTLA-4 group were randomly selected to detect the expression of CD69 in spleen. At the same time, spleen, bone marrow and peripheral blood were collected, and the expression of CD80 on neutrophils was detected by flow cytometry. The expression of CTLA-4 on the surface of T lymphocytes in spleen was detected by immunofluorescence and flow cytometry. The remaining mice in each group were used to observe the 96-hour survival after operation.② In vitro experiment 1: neutrophils were extracted from bone marrow of healthy mice and stimulated with LPS (1 mg/L) for 4, 8 and 12 hours respectively. The control group was added with the same amount of phosphate buffered saline (PBS) at each time point, and the expression of CD80 was detected at each time point.③ In vitro experiment 2: splenic T lymphocytes of healthy mice were extracted and divided into PBS control group, LPS group (final concentration of LPS 1 mg/L), neutrophil group and neutrophil+LPS group. In the latter two groups, the co-culture model of neutrophils and T lymphocytes was established, and then the corresponding treatment was given to detect the expression of CTLA-4 on the surface of T lymphocytes. With the above four groups as controls, CTLA-4 antibody treatment groups (final concentration of CTLA-4 antibody 50 mg/L) were set up respectively. After 48 hours, the level of interleukin-2 (IL-2) in the cell supernatant was detected by enzyme linked immunosorbent assay (ELISA). Results:① Results of in vivo experiment: compared with Sham group, the expression of CD80 on neutrophils in spleen, bone marrow and peripheral blood was significantly up-regulated, while the expression of CTLA-4 on the surface of T lymphocytes was significantly increased [(9.98±0.84)% vs. (3.48±0.64)%, P < 0.05]. It suggested that neutrophils may affect T lymphocytes function through CD80/CTLA-4 pathway in sepsis. Compared with CLP group, CTLA-4 antibody could significantly improve the 96-hour cumulative survival rate of CLP mice (56.25% vs. 18.75%, P < 0.05), and increase the expression of CD69 on the surface of T lymphocytes. It suggested that CTLA-4 antibodies might increase T lymphocytes activation in sepsis and improve survival. ② Results of in vitro experiment: with the prolongation of LPS stimulation, the expression of CD80 on neutrophils gradually increased in time-dependent manner as compared with PBS control group [4 hours: (6.35±0.40)% vs. (3.41±0.40)%, 8 hours: (8.57±0.64)% vs. (3.09±0.27)%, 12 hours: (19.83±1.06)% vs. (5.16±0.36)%, all P < 0.05]. Compared with PBS control group, the expression of CTLA-4 on CD4 +/CD8 + T lymphocytes was not significantly affected by LPS stimulation alone, but CTLA-4 was increased after co-culture with neutrophils [CD4 +: (4.92±0.30)% vs. (3.33±0.25)%, CD8 +: (4.26±0.21)% vs. (2.53±0.66)%, both P < 0.05], and the increased trend of CTLA-4 was more obvious after co-culture with LPS-stimulated neutrophils [CD4 +: (6.34±0.50)% vs. (3.33±0.25)%, CD8 +: (6.21±0.41)% vs. (2.53±0.66)%, both P < 0.05]. In the PBS control group and LPS group, CTLA-4 antibody had no significant effect on IL-2 secretion of T lymphocytes. Compared with PBS control group, co-culture with neutrophils could inhibit the secretion of IL-2 by T lymphocytes (ng/L: 1 938.00±68.45 vs. 2 547.00±218.00, P < 0.05), and the inhibitory effect of neutrophils stimulated by LPS was more obvious (ng/L: 1 073.00±34.39 vs. 2 547.00±218.00, P < 0.05). CTLA-4 antibodies could partially restore IL-2 secretion. In conclusion, after promoting the expression of CTLA-4 on the surface of T lymphocytes, neutrophils might mediate the inhibition of T lymphocytes function by reducing the production of IL-2. Conclusions:Neutrophils mediate T lymphocytes dysfunction in sepsis, and the CD80/CTLA-4 pathway plays an important role. The CTLA-4 antibody improves survival and T lymphocytes function in sepsis mice, which may be a new method of immunotherapy for sepsis.

Objective:To investigate the effect of heparin-binding protein (HBP) on the damage of vascular permeability in early burn.Methods:① Clinical research: 12 patients with severe burns admitted to Suzhou Hospital of Nanjing Medical University from January 1st to August 30th in 2019 were enrolled. Eight patients with severe trauma admitted to the same hospital during the same period were also enrolled as controls to explain the specificity of burn injury. Whole blood samples were obtained within 0.5 hour after admission. The white blood cell count (WBC), absolute value and ratio of neutrophils, and serum HBP levels were measured. Serum samples of 12 patients with severe burn were collected within 9 days after admission, and enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of metabolism products of glycocalyx including syndecan-1 and hyaluronic acid (HA). The correlation between HBP and neutrophils ratio, syndecan-1 and HA were analyzed by linear correlation. ② Basic research: a 30% total body surface area (TBSA) Ⅲ° burn model of Sprague-Dawley (SD) rat aged 6-8 weeks was prepared. In low molecular weight heparin (LMWH) intervention group ( n = 5), 200 U/kg LMWH was injected subcutaneously immediately and every 2 hours after injury for 4 times in total; the burn group ( n = 5) was given the same amount of normal saline. No intervention was given to the normal control group ( n = 5). The peripheral venous blood was collected at 0, 2, 4, and 8 hours after injury, and the serum levels of HBP, syndecan-1 and HA were measured; the injury of glycocalyx on pulmonary vascular endothelial cells was observed under transmission electron microscope. Results:① Clinical research results: the WBC, neutrophils absolute value and ratio, and HBP levels were increased in 12 patients with severe burn and 8 patients with severe trauma. There was no significant difference in the WBC, absolute value and ratio of neutrophils between severe burn and severe trauma patients [WBC (×10 9/L): 14.5±6.1 vs. 10.8±3.6, the absolute value of neutrophils (×10 9/L): 12.0±5.9 vs. 9.0±4.0, the ratio of neutrophils: 0.81±0.10 vs. 0.79±0.14, all P > 0.05], but the HBP levels in the burn patients were significantly higher than those in the trauma patients (μg/L: 192.92±61.73 vs. 51.17±23.05, P < 0.01). Twelve patients with severe burns had a sharp increase in serum syndecan-1 and HA levels after burns, which continued to maintain high levels and peaked at the 9th day [syndecan-1 (μg/L): 16.02±0.39, HA (μg/L): 106.83±4.90]. The analysis showed that HBP was positively correlated with neutrophils ratio, syndecan-1 and HA in severe burn patients at the 1st day after admission ( r values were 0.805, 0.732 and 0.900, respectively, all P < 0.01). It indicated that the sharp increase of neutrophils after the burn released a lot of HBP, and the glycocalyx of the vascular endothelium was severely damaged. ② Basic research results: the levels of serum HBP, syndecan-1 and HA in the burn group were increased sharply as compared with the normal control group, and continued to increase with time, reaching a peak at 8 hours after burn. In the LMWH intervention group, the serum levels of HBP, syndecan-1 and HA were significantly lower than those in the burn group, and the difference was still statistically significant after 8 hours [HBP (μg/L): 6.47±0.25 vs. 12.48±0.08, syndecan-1 (μg/L): 19.06±1.48 vs. 25.92±3.34, HA (μg/L): 35.76±2.10 vs. 54.91±2.64, all P < 0.01]. The results of transmission electron microscopy showed that in the normal control group, the glycocalyx pulmonary vascular endothelial cells was continuous, evenly distributed and dense. The glycocalyx on pulmonary vascular endothelial cells of rats were significantly damaged and shed 2 hours after burn in the burn group, and no glycocalyx was observed at 8 hours. In the LMWH intervention group, the glycocalyx on pulmonary vascular endothelial cells was damaged and the phenomenon of shedding was significantly relieved, and the glycocalyx could be observed 8 hours after the injury. Conclusion:The massive exudation of body fluids and the significant increase of vascular permeability in patients in early burns may be related to the destruction of the glycocalyx on endothelial cells by HBP released from increased neutrophils.

Objective:To investigate the value of 3D printing technology in sphenoid ridge meningioma dissection. Methods:By using craniocerebral spiral enhanced CT scan DICOM images, the skull, vessels, and tumor were extracted, reconstructed, and assembled and integrated in the same coordinate system. Then, we constructed a 3D virtual model and a 3D-printed entity model, which was ap-plied for preoperation and postoperation. Results:Virtual models of the brains of five patients were reconstructed successfully and 3D entity models were produced. The models expressed the relationship among tumors, adjacent blood vessels, and the important posi-tion of the nerve tissue. Then, the models were applied to the reference before surgery planning and after surgery. Five cases were successfully performed. Conclusion:The use of the entity model of sphenoid ridge meningioma is important in optimizing operation plans, improving tumor resection, and reducing intraoperative bleeding.

Objective:To investigate the regulatory effects and mechanism of Nocardia rubra cell wall skeleton (Nr-CWS) on the biological function of human neutrophils. Methods:The experimental research method was used. Fifteen healthy adult volunteers (7 males and 8 females, aged 24 to 45 years) were recruited from Suzhou Physical Examination Center for physical examination from May to October 2022, the peripheral venous blood was collected, and neutrophils were extracted by immunomagnetic bead sorting. The cells were divided into normal control group without any treatment, Nr-CWS alone group treated with Nr-CWS of final mass concentration 60 ng/mL alone, endotoxin/lipopolysaccharide (LPS) alone group stimulated with LPS of final mass concentration 1 μg/mL alone, and LPS+Nr-CWS group stimulated with LPS first and then treated with Nr-CWS as before. After 1 h of culture, the chemotaxis distance, chemotactic cell percentage, chemotactic index, maximum chemotactic speed, and chemotactic function score of neutrophils were detected using the modified agarose chemotactic model; the proportion and fluorescence intensity of phagocytosis cells, the level of reactive oxygen species (ROS), the protein expression levels of granular protein CD35, CD66b, and CD63, and the concentrations of inflammatory cytokines of interleukin 2 (IL-2), IL-4, IL-6, IL-10, IL-17A, tumor necrosis factor alpha (TNF-α), and interferon-γ in cell culture supernatant were detected by flow cytometry. The number of samples in each group in the above experiments was 15. Data were statistically analyzed with analysis of variance for factorial design and independent sample t test. Results:After 1 h of culture, the chemotactic function score of cells in normal control group, Nr-CWS alone group, LPS alone group, and LPS+Nr-CWS group were 15.0, 14.5±0.5, 1.5±0.5, 12.0±1.5, respectively. Compared with those in normal control group, the chemotaxis distance, chemotactic cell percentage, chemotactic index, maximum chemotactic speed, and chemotactic function score of cells were significantly decreased in LPS alone group and LPS+Nr-CWS group (with t values of 18.36, 18.88, 54.28, 18.36, 46.77, 10.58, 14.74, 6.84, 10.58, and 4.24, respectively, P<0.05); compared with those in LPS alone group, the five chemotactic function indexes as above in LPS+Nr-CWS group were significantly increased (with t values of 11.47, 14.65, 11.62, 11.47, and 13.75, respectively, P<0.05). After 1 h of culture, compared with those in normal control group, the proportion and fluorescence intensity of phagocytosis cells were significantly increased in Nr-CWS alone group (with t values of 6.86 and 6.73, respectively, P<0.05), and the above two indexes were significantly decreased in LPS alone group (with t values of 7.35 and 22.72, respectively, P<0.05) and LPS+Nr-CWS group (with t values of 21.37 and 13.10, respectively, P<0.05). After 1 h of culture, compared with that in normal control group, the level of ROS of cells in LPS alone group was significantly increased ( t=6.64, P<0.05); compared with that in LPS alone group, the level of ROS of cells in LPS+Nr-CWS group was significantly decreased ( t=5.46, P<0.05). After 1 h of culture, compared with those in normal control group, the protein expressions of CD35, CD66b, and CD63 of cells were significantly increased in LPS alone group and LPS+Nr-CWS group (with t values of 16.75, 17.45, 10.82, 5.70, 19.35, and 15.37, respectively, P<0.05); compared with those in LPS alone group, the protein expressions of CD35, CD66b, and CD63 of cells were significantly decreased in LPS+Nr-CWS group (with t values of 4.92, 5.72, and 3.18, respectively, P<0.05). After 1 h of culture, compared with those in normal control group, the concentrations of IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and interferon-γ in cell culture supernatant were significantly increased in LPS alone group (with t values of 22.10, 9.50, 7.21, 10.22, 24.88, 8.43, and 47.48, respectively, P<0.05), and the concentrations of IL-6, IL-10, IL-17A, TNF-α, and interferon-γ in cell culture supernatant were significantly increased in LPS+Nr-CWS group (with t values of 4.68, 5.12, 8.02, 5.58, and 7.13, respectively, P<0.05); compared with those in LPS alone group, the concentrations of IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and interferon-γ in cell culture supernatant were significantly decreased in LPS+Nr-CWS group (with t values of 5.39, 2.83, 5.79, 2.90, 5.87, 4.88, and 39.64, respectively, P<0.05). Conclusions:Nr-CWS can enhance the phagocytosis ability of neutrophils in normal condition and improve the chemotactic function, ROS level, degranulation protein level, and inflammatory factor level of human neutrophils in infectious condition. Nr-CWS can enhance the anti-infection ability of human neutrophils by regulating its biological behavior in innate immunity.

OBJECTIVE: To investigate the effect and mechanism of autophagy on the expression of neutrophil programmed death ligand-1 (PD-L1) in mice with sepsis. METHODS: (1) In vivo experiment: male C57BL/6 mice aged 6-8 weeks were divided into sham operation group (Sham group), cecum ligation and perforation (CLP) group, and rapamycin (RAP)+CLP group by random number table with 10 mice in each group. The sepsis model was reproduced by CLP, and the cecum and perforation were not ligated in Sham group, and other operations were the same as CLP group. The mice in RAP+CLP group were intraperitoneally injected with autophagy agonist RAP 4 mg×kg^-1×d^-1 7 days before modeling, while the mice in Sham group and CLP group were not treated. Lung, liver, spleen and pancreas tissues were harvested for immunohistochemical staining 4 days after the operation, and the infiltration of neutrophils in various organs was observed under light microscope. Meanwhile, the expressions of immunosuppressive molecule PD-L1 and autophagy marker microtubule-associated protein 1 light chain 3 (LC3) in lung neutrophils were determined by immunofluorescence staining. (2) In vitro experiment: mouse bone marrow neutrophils were extracted and re-suspended to 1×10¹⁰/L, and they were divided into blank control group (without any treatment), RAP control group (RAP 100 μmol/L), autophagy inhibitor Bafilomycin A1 (Baf) control group (Baf 10 μmol/L), lipopolysaccharide (LPS) stimulation group (LPS 1 mg /L), RAP+LPS group, and Baf+LPS group. The latter two groups were pretreated with 100 μmol/L RAP or 10 μmol/L Baf 30 minutes before LPS stimulation, respectively. The expression of PD-L1 mRNA of neutrophils was determined by reverse transcription-polymerase chain reaction (RT-PCR) at 0, 4, 12 hours after LPS stimulation. At the same time, the expressions of PD-L1, LC3 and p62 at the protein level were determined by Western Blot. RESULTS: (1) In vivo experiment: according to immunohistochemical experiments, a large amount of infiltration of neutrophils in lung, liver, spleen and pancreas was found at 4 hours after CLP. In the immunofluorescence, with the time extension after CLP, the positive expression of LC3 in the lung tissue showed a decreased tendency, and PD-L1 expression was significantly increased. RAP pretreatment could promote the expression of LC3 and reduce the expression of PD-L1 in CLP mice. (2) In vitro experiment: in terms of mRNA levels, with the extension of LPS stimulation time, the expression of PD-L1 mRNA in mouse neutrophils was increased continuously, and peaked at 12 hours, it was significantly higher than that in the blank control group (2^-ΔΔCT: 72.2±10.0 vs. 13.0±0.8, P < 0.01). Compared with LPS stimulation group, the expression of PD-L1 mRNA in RAP+LPS group was significantly down-regulated [12-hour PD-L1 mRNA (2^-ΔΔCT): 47.4±7.3 vs. 72.2±10.0, P < 0.01]. In Baf+LPS group, PD-L1 mRNA expression was significantly up-regulated as compared with that in LPS stimulation group [12-hour PD-L1 mRNA (2^-ΔΔCT): 109.1±7.4 vs. 72.2±10.0, P < 0.01]. At the protein levels, at 4 hours after LPS stimulation, the positive expressions of PD-L1, LC3 and p62 were increased significantly as compared with those in the blank control group, and PD-L1 and p62 were increased continuously with time. Compared with the LPS stimulation group, the expressions of PD-L1 and p62 in the RAP+LPS group were significantly down-regulated, while the expression of LC3 was continually increased, indicating that the level of autophagy was increased, and autophagy was circulated smoothly. On the contrary, the expressions of PD-L1, LC3 and p62 in the Baf+LPS group were significantly up-regulated, indicating that the binding of autophagy and lysosome was blocked, and autophagy was not smooth. CONCLUSIONS In sepsis, the infiltration of neutrophils in all organs increased, and the expression of PD-L1 of neutrophils in lungs was increased significantly, while the expression level of autophagy was decreased. The expression of PD-L1 stimulated by LPS can be inhibited by autophagy agonists, and promoted by autophagy inhibitors. PD-L1 has a negative regulatory effect on sepsis. It can reduce the expression of PD-L1 molecule in sepsis by targeting autophagy, so as to improve sepsis.
Animals ; Autophagy ; B7-H1 Antigen/metabolism* ; Male ; Mice ; Mice, Inbred C57BL ; Models, Animal ; Neutrophils ; Sepsis

Objective: To observe the changes of peripheral blood neutrophil apoptosis rate and the effect of p38 mitogen-activated protein kinase (p38MAPK) inhibitor on peripheral blood neutrophil apoptosis in severely burned patients. Methods: Severe burn patients [burn area ≥ 30% total body surface area (TBSA), deep Ⅱ to Ⅲ degrees, burn index ≥ 20%, age > 20 years old] admitted to the department of burn and plastic surgery of Affiliated Suzhou Hospital of Nanjing Medical University from January to May in 2019 and health examination volunteers during the same period were enrolled. The peripheral blood neutrophils were isolated by Ficoll gradient centrifugation. The neutrophils of severely burned patients were divided into burn group and p38MAPK inhibitor SB203580 group (after 30 minutes incubation at room temperature and 24 hours incubation in incubator); the neutrophils of healthy volunteers were used as control group. The apoptosis of neutrophils was detected by flow cytometry; the level of reactive oxygen species (ROS) in neutrophils was detected by fluorescence probe; the expression of p38MAPK protein and its phosphorylation (p-p38MAPK) level were detected by Western Blot. Results: Compared with the control group, the apoptosis rate of neutrophils in burn group was significantly decreased [(37.42±3.14)% vs. (50.20±9.87)%, P < 0.05], and the ROS production level in neutrophils was significantly increased (fluorescence intensity: 83.28±0.29 vs. 75.23±0.34, P < 0.05). The apoptosis rate of neutrophils in SB203580 group was further lower than that in burn group [(25.51±1.56)% vs. (37.42±3.14)%, P < 0.05], and the level of ROS production was further higher than that in burn group (fluorescence intensity: 95.56±3.67 vs. 83.28±0.29, P < 0.05). There was no significant difference in the protein expression of p38MAPK among the three groups. The p-p38MAPK protein level in burn group was significantly lower than that in control group (p-p38MAPK/p38MAPK: 0.45±0.06 vs. 0.91±0.09, P < 0.05), while the expression level of p-p38MAPK in SB203580 group was further lower than that in burn group (p-p38MAPK/p38MAPK: 0.22±0.04 vs. 0.45±0.06, P < 0.05). Conclusion Peripheral blood neutrophil apoptosis delayed and ROS production were increased in severely burned patients. The mechanism may be related to p38MAPK pathway inhibitor.