1.Effects of stress-induced protein Sestrin2 on necroptosis of dendritic cells induced by lipopolysaccharide
Mengyao WU ; Renqi YAO ; Yu DUAN ; Lu WANG ; Liyu ZHENG ; Pengyi HE ; Ning DONG ; Yao WU ; Yongming YAO
Chinese Critical Care Medicine 2024;36(3):237-243
Objective:To investigate the effect of stress-induced protein Sestrin2 (SESN2) on necroptosis of mouse dendritic cell (DC) induced by lipopolysaccharide (LPS) combined with zVAD, a panaspartate-specific cysteine protease (caspase) inhibitor.Methods:The DC2.4 cell line derived from the bone marrow of mouse in the 3rd to 10th generations was cultured. The cells were stimulated with LPS for 0 hour, 6 hours, 12 hours, and 24 hours, and grouped according to the stimulation time points. Western blotting was performed to determine the protein expression of SESN2 in each group. Overexpression empty lentivirus (NC), SESN2 gene overexpression RNA sequence lentivirus (SESN2 LV-RNA), small interfering empty lentivirus (NS), and SESN2 gene small interfering RNA sequence lentivirus (SESN2 siRNA) were transfected into DC2.4 cells. After 72 hours of transfection, cell fluorescence expression was observed under the inverted fluorescence microscope. Cells in each transfection group were stimulated with LPS for 24 hours. The blank control groups were set up and cultured with phosphate buffered saline (PBS) for 24 hours. Western blotting was performed to measure SESN2 protein expression. In the same groups as above, cells were stimulated with LPS+zVAD for 24 hours. The blank control groups were set up and cultured with PBS for 24 hours. Western blotting was used to determine the expression of mixed lineage kinase domain-like protein (MLKL) and phosphorylated-MLKL (p-MLKL). The p-MLKL levels and the number of positive cells were observed using laser scanning confocal microscopy. The necroptotic cell ratios were assessed by both flow cytometry and Hoechst staining.Results:Compared to the LPS 0 hour group, the expression of SESN2 in the LPS 24 hours group showed a significant increase. Therefore, 24 hours was chosen as the subsequent stimulation time point. After successful lentivirus transduction and 24 hours of cultivation, the MLKL phosphorylation level in the SESN2 siRNA+LPS+zVAD group was significantly higher than that in the NS+LPS+zVAD group. The MLKL phosphorylation in the SESN2 LV-RNA+LPS+zVAD group was significantly lower than that in the NC+LPS+zVAD group. The MLKL phosphorylation levels in both the NS+LPS+zVAD group and the NC+LPS+zVAD group were obviously higher than those in the NS+PBS group and the NC+PBS group, respectively. Laser scanning confocal microscopy showed that the trends in quantity and fluorescence intensity of p-MLKL protein expressions were consistent with the above results. The results from flow cytometry analysis and Hoechst staining showed that the rates of cell necrotic apoptosis in SESN2 siRNA+LPS+zVAD group were significantly higher than those in NS+LPS+zVAD group [flow cytometry analysis: (30.800±1.153)% vs. (20.800±1.114)%, Hoechst staining: (75.267±0.451)% vs. (46.267±3.371)%, both P < 0.05], indicating that knocking down SESN2 further exacerbated the occurrence of necroptosis. The necrotic apoptosis rates in SESN2 LV-RNA+LPS+zVAD group were significantly lower than those in NC+LPS+zVAD group [flow cytometry analysis: (7.160±0.669)% vs. (19.240±2.322)%, Hoechst staining: (32.433±3.113)% vs. (48.567±4.128)%, both P < 0.05], indicating that overexpressing SESN2 reversed such response and markedly reduced the proportion of necroptotic cells compared to the corresponding empty vector group. Conclusion:SESN2 exhibits an inhibitory effect on necroptosis of DC in sepsis. Targeted SESN2 expression may regulate the process of DC-mediated immune response in sepsis.
2.Chinese expert consensus on the diagnosis and treatment of traumatic supraorbital fissure syndrome (version 2024)
Junyu WANG ; Hai JIN ; Danfeng ZHANG ; Rutong YU ; Mingkun YU ; Yijie MA ; Yue MA ; Ning WANG ; Chunhong WANG ; Chunhui WANG ; Qing WANG ; Xinyu WANG ; Xinjun WANG ; Hengli TIAN ; Xinhua TIAN ; Yijun BAO ; Hua FENG ; Wa DA ; Liquan LYU ; Haijun REN ; Jinfang LIU ; Guodong LIU ; Chunhui LIU ; Junwen GUAN ; Rongcai JIANG ; Yiming LI ; Lihong LI ; Zhenxing LI ; Jinglian LI ; Jun YANG ; Chaohua YANG ; Xiao BU ; Xuehai WU ; Li BIE ; Binghui QIU ; Yongming ZHANG ; Qingjiu ZHANG ; Bo ZHANG ; Xiangtong ZHANG ; Rongbin CHEN ; Chao LIN ; Hu JIN ; Weiming ZHENG ; Mingliang ZHAO ; Liang ZHAO ; Rong HU ; Jixin DUAN ; Jiemin YAO ; Hechun XIA ; Ye GU ; Tao QIAN ; Suokai QIAN ; Tao XU ; Guoyi GAO ; Xiaoping TANG ; Qibing HUANG ; Rong FU ; Jun KANG ; Guobiao LIANG ; Kaiwei HAN ; Zhenmin HAN ; Shuo HAN ; Jun PU ; Lijun HENG ; Junji WEI ; Lijun HOU
Chinese Journal of Trauma 2024;40(5):385-396
Traumatic supraorbital fissure syndrome (TSOFS) is a symptom complex caused by nerve entrapment in the supraorbital fissure after skull base trauma. If the compressed cranial nerve in the supraorbital fissure is not decompressed surgically, ptosis, diplopia and eye movement disorder may exist for a long time and seriously affect the patients′ quality of life. Since its overall incidence is not high, it is not familiarized with the majority of neurosurgeons and some TSOFS may be complicated with skull base vascular injury. If the supraorbital fissure surgery is performed without treatment of vascular injury, it may cause massive hemorrhage, and disability and even life-threatening in severe cases. At present, there is no consensus or guideline on the diagnosis and treatment of TSOFS that can be referred to both domestically and internationally. To improve the understanding of TSOFS among clinical physicians and establish standardized diagnosis and treatment plans, the Skull Base Trauma Group of the Neurorepair Professional Committee of the Chinese Medical Doctor Association, Neurotrauma Group of the Neurosurgery Branch of the Chinese Medical Association, Neurotrauma Group of the Traumatology Branch of the Chinese Medical Association, and Editorial Committee of Chinese Journal of Trauma organized relevant experts to formulate Chinese expert consensus on the diagnosis and treatment of traumatic supraorbital fissure syndrome ( version 2024) based on evidence of evidence-based medicine and clinical experience of diagnosis and treatment. This consensus puts forward 12 recommendations on the diagnosis, classification, treatment, efficacy evaluation and follow-up of TSOFS, aiming to provide references for neurosurgeons from hospitals of all levels to standardize the diagnosis and treatment of TSOFS.
3.Role of apurinic/apyrimidinic endodeoxyribonuclease 1 in ferroptosis of mouse dendritic cells under simulated sepsis
Qiyuan ZHOU ; Jingyan LI ; Yongming YAO ; Yingping TIAN
Chinese Journal of Burns 2024;40(10):930-939
Objective:To investigate the role of apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) in ferroptosis of mouse dendritic cells (DCs) under simulated sepsis, providing evidence for improving immunosuppression in sepsis caused by wound infection.Methods:This study was an experimental research. The mouse DC line DC2.4 in the logarithmic growth phase (with passages 3-10) was used for the experiments (with each sample size of 3). The sepsis model was established by treating DCs with 1 μg/mL lipopolysaccharide (LPS, same concentration throughout) for 0 (untreated), 6, 12, 24, 48, and 72 h. Western blotting was used to detect the protein expressions of APE1 and anti-ferroptosis proteins glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) in cells, flow cytometry was employed to detect reactive oxygen species (ROS) levels in cells, and live-cell imaging technology was used to measure cell lipid peroxidation levels. DCs successfully transfected with lentivirus containing APE1 short hairpin RNA sequence were divided into APE1-knockdown+phosphate buffer solution (PBS) group and APE1-knockdown+LPS group. DCs successfully transfected with empty lentivirus were divided into empty vector+PBS group and empty vector+LPS group. After stimulation with PBS or LPS and 24 h of culture, corresponding assays were conducted as above. DCs transfected with lentivirus containing APE1 overexpression RNA sequence were divided into APE1-overexpression+PBS group and APE1-overexpression+LPS group. DCs transfected with empty lentivirus were divided into empty vector+PBS group and empty vector+LPS group. After stimulation with PBS or LPS and 24 h of culture, corresponding assays were conducted as above. A total of 88 male C57BL/6J mice aged 6-8 weeks were divided into corn oil+sham injury group, corn oil+cecal ligation and puncture (CLP) group, inhibitor+sham injury group, and inhibitor+CLP group ( n=22) according to the random number table. Mice in the two inhibitor groups were gavaged with APE1 inhibitor E3330 (1 mg/mL in concentration) at 40 mg/kg per day, while mice in the two corn oil groups were gavaged with an equal amount of corn oil daily. Two weeks later, mice in the two CLP groups underwent CLP surgery to establish a sepsis model, while mice in the two sham injury groups underwent sham injury. Sixteen mice from each group were selected to observe survival within 7 d post-surgery. At 24 h post-surgery, CD11c-positive magnetic beads were used to extract spleen DCs from the remaining six mice in each group for corresponding assays ( n=3) as above. Results:Compared with that of LPS treatment at 0 h, APE1 protein expression significantly increased in cells at 6 h of LPS treatment ( P<0.05), APE1 and GPX4 protein expressions significantly decreased at 24, 48, and 72 h of LPS treatment, SLC7A11 protein expression significantly decreased at 24 h of LPS treatment ( P<0.05), while the ROS level in cells ( P<0.05) and cell lipid peroxidation level significantly increased at 24, 48, and 72 h of LPS treatment. After 24 h of culture, the GPX4 protein expression of cells in APE1-knockdown+LPS group was significantly lower than that in APE1-knockdown+PBS group ( P<0.05), while the ROS level in cells ( P<0.05) and cell lipid peroxidation level were significantly higher than those in APE1-knockdown+PBS group and empty vector+LPS group. After 24 h of culture, APE1, SLC7A11, and GPX4 protein expressions of cells in APE1-overexpression+LPS group were significantly higher than those in empty vector+LPS group ( P<0.05), while the ROS level in cells ( P<0.05) and cell lipid peroxidation level were significantly lower than those in empty vector+LPS group. At 24 h post-surgery, APE1 and GPX4 protein expressions of mice cells in inhibitor+CLP group were significantly lower than those in inhibitor+sham injury group and corn oil+CLP group ( P<0.05); the ROS level of mice cells in corn oil+CLP group (12 693±913) was significantly higher than that in corn oil+sham injury group (4 205±805, P<0.05), while the ROS level of mice cells in inhibitor+CLP group (18 085±223) was significantly higher than that in inhibitor+sham injury group (4 381±787) and corn oil+CLP group (with P values all <0.05); the cell lipid peroxidation level of mice in inhibitor+CLP group was significantly higher than that in inhibitor+sham injury group and corn oil+CLP group. Within 7 d post-surgery, the survival ratio of mice in inhibitor+CLP group was significantly lower than that in inhibitor+sham injury group ( χ2=22.67, P<0.05). Conclusions:Under simulated sepsis, the APE1 expression in mouse DCs is decreased, and oxidative stress and ferroptosis are enhanced; knocking down the APE1 exacerbates DC ferroptosis, while APE1 overexpression effectively reduces DC ferroptosis. The inhibition of APE1 expression in DCs is closely associated with poor prognosis in sepsis.
4.Effects of stimulator of interferon gene on ferroptosis mediated by acyl-CoA synthetase long-chain family member 4 in mouse dendritic cells under sepsis
Mengyao WU ; Pengyi HE ; Yu DUAN ; Liyu ZHENG ; Renqi YAO ; Qiyuan ZHOU ; Yu CHEN ; Ning DONG ; Yao WU ; Yongming YAO
Chinese Journal of Burns 2024;40(10):920-929
Objective:To investigate the effects of stimulator of interferon gene (STING) on ferroptosis mediated by acyl-CoA synthetase long-chain family member 4 (ACSL4) in mouse dendritic cells (DCs) under sepsis, providing a basis for improving the dysregulation of immune response in sepsis caused by factors such as wound infection.Methods:This study was an experimental research. The mouse DC line DC2.4 in the logarithmic growth phase (with passages 3-10) were divided into lipopolysaccharide (LPS) stimulation 0 h (unstimulated) group, LPS stimulation 6 h group, LPS stimulation 12 h group, LPS stimulation 18 h group, and LPS stimulation 24 h group according to the random number table (the same grouping method below), which were cultured with 1 μg/mL LPS (the same concentration below) for the corresponding time. The protein expressions of phosphorylated STING (p-STING), STING, and ACSL4 in cells were determined by Western blotting. DC2.4 successfully transfected with lentivirus containing STING gene small interfering RNA (hereinafter referred to as siSTING) were divided into siSTING+phosphate buffer solution (PBS) group and siSTING+LPS group. DC2.4 successfully transfected with empty lentivirus were divided into empty vector+PBS group and empty vector+LPS group. After being stimulated with PBS or LPS and cultured for 24 hours, the protein expressions of p-STING, STING, and ACSL4 in cells were determined as above. Cell lipid peroxidation degrees were observed using the lipid peroxidation assay kit, and cell apoptosis rates were detected using flow cytometry. The sample numbers in the above cell experiments were all 3. Eighty male C57BL/6J mice aged 6 to 8 weeks were divided into sham surgery+normal saline (NS) group, cecal ligation and puncture (CLP)+NS group, sham surgery+C-176 group, and CLP+C-176 group, with 20 mice in each group. Mice in the two C-176 groups were intraperitoneally injected with C-176, while mice in the two NS groups were intraperitoneally injected with an equivalent volume of NS. One hour later, sham surgery was performed on the mice in the two sham surgery groups, and CLP surgery was performed on the mice in the two CLP groups to establish a sepsis model. At 24 h post-surgery, 10 mice from each group were sacrificed to extract spleen DCs, and protein expression, lipid peroxidation, and apoptosis rates were detected as above ( n=3). Hematoxylin-eosin staining was performed to observe pathological damage in the heart, liver, lung, and kidney tissue. The remaining 10 mice in each group were observed for survival within 7 days after surgery. Results:The protein expressions of p-STING, STING, and ACSL4, as well as the p-STING/STING ratio in DC2.4 in LPS stimulation 24 h group were significantly higher than those in LPS stimulation 0 h group ( P<0.05). After 24 h of culture, the protein expressions of p-STING, STING, and ACSL4 in DC2.4 in siSTING+LPS group and empty vector+PBS group were significantly lower than those in empty vector+LPS group ( P<0.05); the lipid peroxidation degrees of DC2.4 in siSTING+LPS group and empty vector+PBS group were weaker than those in empty vector+LPS group. The apoptosis rates of DC2.4 in empty vector+PBS group, empty vector+LPS group, siSTING+PBS group, and siSTING+LPS group were (15.7±3.0)%, (37.8±2.9)%, (13.1±2.1)%, and (20.6±1.8)%, respectively. The apoptosis rates of DC2.4 in empty vector+PBS group and siSTING+LPS group were significantly lower than that in empty vector+LPS group ( P<0.05). At 24 h post-surgery, the protein expressions of p-STING and ACSL4, and the p-STING/STING ratio in spleen DCs of mice in CLP+NS group were significantly higher than those in sham surgery+NS group and CLP+C-176 group ( P<0.05); the protein expression of STING in spleen DCs of mice in CLP+NS group was significantly higher than that in sham surgery+NS group ( P<0.05); the lipid peroxidation degrees of spleen DCs of mice in CLP+C-176 group and sham surgery+NS group were weaker than that in CLP+NS group. The apoptosis rates of spleen DCs of mice in sham surgery+NS group and CLP+C-176 group were significantly lower than that in CLP+NS group ( P<0.05), and the apoptosis rate of spleen DCs of mice in CLP+C-176 group was significantly higher than that in sham surgery+C-176 group ( P<0.05). Pathological tissue damage in the heart, liver, lung, and kidney of mice in CLP+NS group was significantly worse than that in sham surgery+NS group, while such damage in the above organs of mice in CLP+C-176 group was significantly alleviated compared with that in CLP+NS group. The survival ratio of mice in CLP+NS group within 7 days after surgery was significantly lower than that in sham surgery+NS group ( χ2=8.30, P<0.05). Conclusions:Under sepsis, STING activation in mouse DCs is significant, which enhances ACSL4-mediated ferroptosis. Inhibiting STING activation can significantly reduce ACSL4-mediated ferroptosis level in mouse DCs under sepsis, thereby improving the survival rate of septic mice.
5.Classification of sepsis: the cornerstone for precise treatment
Yongming YAO ; Hui ZHANG ; Ning DONG
Chinese Journal of Burns 2024;40(10):915-919
Sepsis appears to be a heterogeneous clinical syndrome. The classification of patients with sepsis is the prerequisite for improving the efficiency of clinical management and is also the basis for achieving precise treatment of sepsis. In recent years, many studies at home and abroad have classified patients with sepsis based on data including their clinical characteristics, laboratory biomarkers, and genomics. This article briefly analyzed several sepsis classification methods that are currently well recognized, with a view to providing new ideas for building a standardized diagnosis and treatment system for sepsis.
6.Study on Metabolomics of Stable Angina Pectoris of Coronary Artery Heart Disease with Spleen Deficiency and Phlegm Turbidity Syndrome Based on LC-MS
Changbin YUAN ; Yuzhu YAO ; Yongming LIU ; Meijia CHENG ; Simeng XIE ; Yetao JU ; Shiyu ZHANG ; Yifan ZENG ; Huiyong ZHANG ; Guanlin YANG ; Dongyu MIN
World Science and Technology-Modernization of Traditional Chinese Medicine 2023;25(9):3105-3113
Objective To analyse the differential metabolites and related metabolic pathways in stable angina pectoris of coronary artery heart disease with spleen deficiency and phlegm turbidity syndrome by serum metabolomics.Methods This study observed 60 patients with stable angina pectoris of coronary artery heart disease with spleen deficiency and phlegm turbidity syndrome and 60 healthy volunteers in the same period.Liquid chromatography-mass spectrometry(LC-MS)was performed on the serum metabonomics.The differential metabolites were identified by multivariate statistical analysis of the original spectrogram and original data,and enrichment analysis of KEGG metabolic pathway was analyzed.Results A total of 60 patients in the group of stable angina pectoris of coronary artery heart disease with spleen deficiency and phlegm turbidity syndrome participated in the study,and a total of 60 healthy volunteers in the control group participated in the study.There was no statistical difference in general information and biochemical indicators between the two groups(P>0.05);Eighteen differential metabolites were found respectively,including phenylacetaldehyde,orthophosphate,guanosine,diethyl phosphate,2-dehydro-d-gluconate,guanine and 5-(2-hydroxyethyl)-4-methylthiazole down-regulated expression,taurocholate,2-propylglutaric acid,8-amino-7-oxononanoate,l-tyrosine,s-sulfo-l-cysteine,cyclohexanecarboxylic acid,porphobilinogen,(r)-acetoin,octanoylglucuronide,melatonin and solanine up-regulated expression,involving phenylalanine metabolism,thiamine metabolism,purine metabolism.Conclusion The differential metabolites reveal the metabolic essence of stable angina pectoris of coronary artery heart disease with spleen deficiency and phlegm turbidity syndrome from the micro level,and can provide clues for clinical early warning of patients with stable angina pectoris of coronary artery heart disease with spleen deficiency and phlegm turbidity syndromet.
7.Clinical effect of free medial plantar flap on reconstruction of severe thumb defect caused by electric burn
Peipeng XING ; Jidong XUE ; Haina GUO ; Haiping DI ; Gaoyuan YANG ; Dayong CAO ; Xiaokai ZHAO ; Yongming YAO ; Chengde XIA
Chinese Journal of Microsurgery 2023;46(5):500-504
Objective:To explore the technique and clinical effects of free medial plantar flap on reconstruction of the severe defect of thumb caused by electric burn.Methods:Surgical techniques and clinical effects were explored in reconstruction with free medial plantar flap for treatment of severe electric burns of thumbs. From July 2016 to July 2021, 18 patients suffered from severe electric burns of thumbs were admitted in the Department of Burn, Zhengzhou First People's Hospital. All the wounds were the entrance of electric burns. After thorough debridement, the arteries, nerves, tendons, phalanges and interphalangeal joints were exposed to various degrees. Damaged digital proper palmar arteries were ligated and defected proper palmar digital nerves were marked and further anastomosed with the nerves carried by the flap. Palmaris longus tendon grafts were employed to reconstruct the defects of flexor pollicis longus tendon. Wounds were closed by transfer of free medial plantar flaps, and the flap donor sites were closed by inguinal skin grafts. Survival of the flap was observed 1 week after surgery, and the survival of the skin graft in the foot donor site 12 days after surgery. Outpatient follow-up including observation of the appearance and texture of the flap, evaluation of sensory function, thumb alignment and finger flexion according to the Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association. Evaluate the scar hyperplasia in the foot donor site and the standing and walking functions of the donor foot.Results:All flaps survived,at 1 week after surgery. On the 12th day after surgery, all 16 foot flap survived, and 2 patients had local necrosis, and the necrosis healed completely after dressing change for 10 days, the wound healed completely. Among them, 3 patients without tendon transfer experienced a rupture of the flexor pollicis longus tendon at 2 months after surgery, and underwent another palmaris longus tendon transfer. After the surgery, functional exercise was performed with the palm and flexor fingers. After 6-12 months of follow-up, the blood supply, appearance, and texture of the flap were good and similar to that of the palmar skin of the thumb, with varying degrees of recovery in sensation. The TPD was 6-11 mm, and the thumb was restored to varying degrees. According to the Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association, 13 cases in excellent and 5 cases in good. Mild scar hyperplasia remains in the flap site of donor feet, which does not affect the standing and walking functions of the donor foot.Conclusion:The texture of medial plantar skin is similar to that of palmar skin, with good wear resistance and good sensation. Furthermore, it causes a little damage to the donor site and without obvious complication. The medial plantar flap is ideal for reconstruction of a severe wound caused by electric burn in thumb.
8.Novel strategy of sepsis immunomodulation targeting dendritic cells
Yongming YAO ; Hui ZHANG ; Yao WU
Chinese Journal of Burns 2023;39(7):606-611
Dendritic cells (DCs) are the major antigen-presenting cells that play critical roles in regulating both innate and acquire immune responses. In the state of sepsis, the number of DCs is obviously decreased with inhibited antigen presenting ability as well as abnormal cytokine secretion, thereby resulting in an impairment of T lymphocyte activation. Previous studies have demonstrated that the depletion and dysfunction of DCs appear to be the main causes associated with the development of sepsis-induced immunosuppression. Based on the characteristic changes of DCs in sepsis and analysis of recent research progress, the authors propose a novel strategy of immunomodulation targeting the apoptosis, differentiation, and dysfunction of DCs, in order to provide new ideas for the prevention and treatment of severe burns and trauma complicated with sepsis.
9.Influence of family with sequence similarity 134, member B-mediated reticulophagy on lipopolysaccharide-induced apoptosis of mouse dendritic cells
Yu DUAN ; Renqi YAO ; Liyu ZHENG ; Ning DONG ; Yao WU ; Yongming YAO ; Xingui DAI
Chinese Journal of Burns 2023;39(9):857-866
Objective:To investigate the influence of family with sequence similarity 134, member B (FAM134B)-mediated reticulophagy on lipopolysaccharide (LPS)-induced apoptosis of mouse dendritic cells (DCs), so as to provide a basis for improving the immune suppression of sepsis caused by wound infection and other factors.Methods:The experimental research methods were used. The DC line DC2.4 of the 3 rd to 10 th passage in the logarithmic growth stage was collected for experiments. DCs were divided into LPS stimulation 0 h (no stimulation) group, LPS stimulation 6 h group, LPS stimulation 12 h group, LPS stimulation 24 h group, and LPS stimulation 72 h group, which were cultured with 1 μg/mL LPS (the same concentration below) for the corresponding time. The protein expressions of FAM134B, microtubule-associated protein 1 light chain 3B (LC3B), and transporter protein SEC61B were determined by Western blotting, and the ratio of LC3B-Ⅱ/LC3B-Ⅰ was calculated ( n=3). DCs were divided into phosphate buffer solution (PBS) group and LPS group for corresponding treatment. After 24 hours of culture, the expression of FAM134B and its co-localization with lysosomal probes and LC3B were detected using immunofluorescence method, while the number of autolysosomes in cells were observed through transmission electron microscope. DCs were divided into the FAM134B-knockdown group that were transfected with lentivirus containing small interfering RNA (siRNA) sequence of FAM134B gene and the empty vector group with empty lentivirus transfected. At post transfection hour 72, the fluorescence expression of cells was observed under the inverted fluorescence phase contrast microscope, meanwhile, the normally cultured DCs were set as blank control group, and the same observation was performed at the corresponding time point. DCs were divided into PBS alone group and LPS alone group, DCs successfully transfected with lentivirus containing siRNA sequence of FAM134B gene were divided into FAM134B-knockdown+PBS group and FAM134B-knockdown+LPS group, and DCs successfully transfected with empty lentivirus were divided into empty vector+PBS group and empty vector+LPS group. These cells were stimulated correspondingly and cultured for 24 hours. The protein expression of FAM134B was detected using Western blotting ( n=3); the apoptotic rate of cells was determined by flow cytometry ( n=3); the situation of apoptosis was observed by Hoechst staining, and the apoptotic rate was calculated ( n=5); the protein expressions of cleaved cysteine aspartic acid specific protease-3 (caspase-3), B cell lymphoma 2 (Bcl-2), and Bcl-2-associated X protein (Bax) were detected using Western blotting, and the ratio of Bax/Bcl-2 was calculated ( n=5). Data were statistically analyzed with one-way analysis of variance (ANOVA), least significant difference test, and ANOVA for factorial design. Results:Compared with those in LPS stimulation 0 h group, the protein expressions of FAM134B of cells in LPS stimulation 12 h group and LPS stimulation 24 h group were significantly increased ( P<0.05), the protein expressions of SEC61B of cells in LPS stimulation 6 h group, LPS stimulation 12 h group, LPS stimulation 24 h group, and LPS stimulation 72 h group were significantly decreased ( P<0.05), and the ratios of LC3B-Ⅱ/LC3B-Ⅰ of cells in LPS stimulation 24 h group and LPS stimulation 72 h group were obviously increased ( P<0.05). As the most significant changes of three proteins were seen in the cells of LPS stimulation 24 h group, 24 h was used as the duration of subsequent LPS stimulation. After 24 hours of culture, the expression of FAM134B and its co-localization with LC3B and lysosomal probes in the cells of LPS group were all significantly enhanced, with a significant increase in the number of autolysosomes in comparison with those in PBS group. Both the empty vector group and the FAM134B-knockdown group showed high intensity fluorescence in the cells at post transfection hour 72, but the blank control group showed no fluorescence in the cells at the corresponding time point. After 24 hours of culture, the protein expression of FAM134B of cells in FAM134B-knockdown+PBS group was significantly lower than the expressions in PBS alone group and empty vector+PBS group (with P values all <0.05), the protein expression of FAM134B of cells in FAM134B-knockdown+LPS group was significantly lower than the expressions in LPS alone group and empty vector+LPS group (with P values all <0.05), the protein expression of FAM134B of cells in LPS alone group was significantly higher than that in PBS alone group ( P<0.05), while the protein expression of FAM134B of cells in empty vector+LPS group was significantly higher than that in empty vector+PBS group ( P<0.05). After 24 hours of culture, flow cytometry assay revealed that the apoptotic rate of cells in PBS alone group, LPS alone group, empty vector+PBS group, empty vector+LPS group, FAM134B-knockdown+PBS group, and FAM134B-knockdown+LPS group were (13.3±0.8)%, (32.6±4.3)%, (17.0±1.5)%, (51.7±3.3)%, (52.4±3.1)%, and (62.3±2.6)%, respectively. After 24 hours of culture, compared with those in LPS alone group and empty vector+LPS group, the protein expression of cleaved caspase-3, the ratio of Bax/Bcl-2, and the apoptotic rates of cells detected by flow cytometry and Hoechst staining were significantly increased in FAM134B-knockdown+LPS group ( P<0.05); compared with those in the corresponding PBS treatment group, namely, PBS alone group, empty vector+PBS group, and FAM134B-knockdown+PBS group, the protein expression of cleaved caspase-3, the ratio of Bax/Bcl-2, and the apoptotic rates of cells detected by flow cytometry and Hoechst staining were significantly increased in LPS alone group, empty vector+LPS group, and FAM134B-knockdown+LPS group ( P<0.05). Conclusions:The activation of reticulophagy mediated by FAM134B in mouse DCs is enhanced and peaked in 24 hours under LPS stimulation, and the activated reticulophagy has a significant inhibitory effect on cell apoptosis.
10.The effect of ribophagy on lipopolysaccharide-induced apoptosis of dendritic cells
Liyu ZHENG ; Renqi YAO ; Ning DONG ; Yao WU ; Yongming YAO
Chinese Journal of Emergency Medicine 2022;31(10):1334-1340
Objective:To investigate the role and significance of NUFIP-1-mediated ribophagy in apoptosis of dendritic cells (DCs) stimulated by lipopolysaccharide (LPS).Methods:Cultured mouse dendritic cell line DC2.4 were divided into the blank control group and LPS stimulation groups for 6, 12, 24, 48 and 72 h ( n=5). LPS subgroups were consistently cultured with 1 μg/mL LPS for the corresponding incubation time. Western blot was adopted to detect the expression levels of NUFIP-1 and autophagy-related proteins p62 and LC3B across groups. Laser scanning confocal microscopy (LSCM) was applied to detect the expression and cellular localization of NUFIP-1, with its co-localization with Lyso-tracker and LC3B, respectively. The silencing blank vector NS and silencing virus vector NUFIP-1 siRNA were transferred into DC2.4 ( n=3) and stimulated with 1 μg/mL LPS for 24 h. The apoptosis of DC2.4 was measured by flow cytometry analysis. The expression levels of apoptosis-related proteins were determined using Western blot, including cleaved caspase-3 and Bcl-2. One-way analysis of variance (ANOVA) was applied for comparison among multiple groups, and LSD-t method was used for subsequent pairwise comparison. A P<0.05 was considered statistically significant. Results:The results of Western blot showed that expression level of NUFIP-1 in DC2.4 revealed a trend of first increasing and subsequent decreasing upon LPS stimulation for different times (6, 12, 24, 48 and 72 h), and the expression level of NUFIP-1 in the LPS 24 h group was significantly higher than that in the blank control group [blank control group: (0.6786 ± 0.0820); LPS 24 h group: (1.4830 ± 0.1170); P<0.01]. Meanwhile, p62 expression in the LPS 24 h group was significantly lower than that in the blank control group [blank control group: (0.9087 ± 0.1235); LPS 24 h group: (0.3113 ± 0.5571); P<0.01]. Moreover, the conversion from LC3B-I to LC3B-II in the LPS 24 h group was significantly higher than that in the blank control group [blank control group: (0.5542 ± 0.1248); LPS 24 h group: (2.5310 ± 0.3119); P<0.01]. LSCM indicated that NUFIP-1 was predominantly located in the nucleus and perinuclear area in DC2.4. The fluorescence intensity of NUFIP-1 increased in a time-dependent manner from 6 h to 24 h after LPS stimulation, whereas a significant reduction could be observed at 48 h and 72 h after LPS stimulation. Meanwhile, the co-localization of NUFIP-1 with Lyso-tracker and LC3B was substantially reinforced in comparison with the blank control group. Transfection of NUFIP-1 siRNA through lentivirus transfection technology significantly down-regulated the expression level of NUFIP-1 in DC2.4, with statistical differences compared with the blank control group and empty vector group [blank control group: (0.6627 ± 0.1707); empty vector group: (0.6966 ± 0.1107); siRNA group: (0.1428 ± 0.0296); P<0.05]. Flow cytometry analysis revealed that the apoptotic rate of LPS-stimulated DC2.4 was significantly higher in the NUFIP-1 siRNA transfection group than that in the blank control group and empty vector group [blank control LPS 24 h group: (47.91% ± 1.006%); empty vector LPS 24 h group: (70.26% ± 1.011%); siRNA LPS 24 h group: (80.23% ± 2.094); P<0.01]. Western blot analysis of apoptosis-related protein further confirmed that the expression level of cleaved caspase-3 was significantly elevated in the NUFIP-1 siRNA transfection group compared to those of the blank control group and empty vector group under LPS challenge [blank control LPS 24 h group: (0.4748 ± 0.0876); empty vector LPS 24 h group: (0.2849 ± 0.0418); siRNA LPS 24 h group: (0.9733 ± 0.0525); P<0.01]. Likewise, expression of Bcl-2, an anti-apoptotic protein was significantly down-regulated in the siRNA LPS 24 h group [blank control LPS 24 h group: (0.7810 ± 0.0490); empty vector LPS 24 h group: (0.8292 ± 0.0729); siRNA LPS 24 h group: (0.3957 ± 0.0838); P<0.05]. Conclusions:NUFIP-1-mediated ribophagy is significantly activated in DC2.4 upon LPS stimulation, exerting an underlying protective effect on apoptosis.

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