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

Objective To explore the effects of lipoxygenase(LOX)on severe fever with thrombocytopenia syndrome virus(SFTSV)in human umbilical vein endothelial cells(HUVECs).Methods The CCK-8 assay was used to assess the cytotoxicity of LOX in HUVECs.Real-time quantitative PCR(qPCR)was adopted to detect the replication of viral RNA in cells.The infection rate of SFTSV to HUVECs was observed via indirect immunofluorescence assay(IFA).The expressions of intracellular viral NP protein and autophagy related proteins microtubule-associated protein 1 light chain 3(LC3)and adenosine 5'-monophosphate-activated protein kinase(AMPK)/mammalian target of rapamycin(mTOR)were detected via Western blotting.Lipid metabolomics was used to analyze the differences in expressions of intracellular metabolites in the SFTSV-infected Huh 7 with or without LOX treatment.Results The results of CCK-8 showed no obvious cytotoxicity to HUVECs with LOX≤8 mg/mL.With the increase of LOX concentrations,the viral RNA level,viral infection rate,and expressions of SFTSV nucleoprotein(NP)protein were gradually decreased,respectively.The autophagy reaction was activated in SFTSV-infected HUVECs,evidenced by the increased expression level of LC3 Ⅱ protein.Compared with the untreated group,LOX treatment resulted in decreased levels of LC3 Ⅱ and AMPK phosphorylation,and enhanced phosphorylation of mTOR in SFTSV-infected HUVEC.Conclusion LOX negatively regulates autophagy by inhibiting AMPK/mTOR signaling pathway,thereby inhibiting SFTSV replication.

Alzheimer's disease (AD) is the major form of dementia in the elderly and is closely related to the toxic effects of microglia sustained activation. In AD, sustained microglial activation triggers impaired synaptic pruning, neuroinflammation, neurotoxicity, and cognitive deficits. Accumulating evidence has demonstrated that aberrant expression of deubiquitinating enzymes is associated with regulating microglia function. Here, we use RNA sequencing to identify a deubiquitinase YOD1 as a regulator of microglial function and AD pathology. Further study showed that YOD1 knockout significantly improved the migration, phagocytosis, and inflammatory response of microglia, thereby improving the cognitive impairment of AD model mice. Through LC-MS/MS analysis combined with Co-IP, we found that Myosin heavy chain 9 (MYH9), a key regulator maintaining microglia homeostasis, is an interacting protein of YOD1. Mechanistically, YOD1 binds to MYH9 and maintains its stability by removing the K48 ubiquitin chain from MYH9, thereby mediating the microglia polarization signaling pathway to mediate microglia homeostasis. Taken together, our study reveals a specific role of microglial YOD1 in mediating microglia homeostasis and AD pathology, which provides a potential strategy for targeting microglia to treat AD.

BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes are involved in multiple injury repair processes,and the effects and the specific mechanisms of renal ischemia/reperfusion injury have not been fully elucidated.OBJECTIVE:To investigate the molecular mechanism of human umbilical cord mesenchymal stem cell-derived exosomes in the treatment of renal ischemia/reperfusion injury.METHODS:(1) Human umbilical cord mesenchymal stem cells were cultured and exosomes were obtained and identified using an exosome extraction kit.(2) The distribution of exosomes in the kidney of mice with renal ischemia/reperfusion injury was examined by intravital fluorescence imaging.(3) Thirty C57/BL6 male mice were divided into five groups according to the random number table method:sham operation group,renal ischemia/reperfusion group,sham operation group+Compound C group,renal ischemia/reperfusion+exosome group (exosome group),and renal ischemia/reperfusion+exosome+Compound C group (exosome+Compound C group),with 6 mice in each group.Except the sham operation group,bilateral renal pedicles were clamped for 45 minutes and a mouse model of renal ischemia/reperfusion injury was established after 24 hours of reperfusion.In sham operation+Compound C group and exosome+Compound C group,AMPK inhibitor Compound C was intraperitoneally injected 30 minutes before model establishment.In the exosome group and exosome+Copmpound C group,exosomes were injected through the tail vein 15 minutes before renal pedicle clipping.The levels of serum creatinine and urea nitrogen,interleukin 6,and tumor necrosis factor α in renal tissue,and the expression of apoptosis-related factors in renal tissue were detected after 24 hours of reperfusion in each group.RESULTS AND CONCLUSION:(1) Human umbilical cord mesenchymal stem cell exosomes had the typical tea tray morphology,with the diameter distribution in the range of 40-160 nm,and expressed the specific marker membrane protein of exosome surface.(2) Murine kidneys after renal ischemia/reperfusion injury were more likely to gather human umbilical cord mesenchymal stem cell exosomes compared with the sham operation group.(3) Exosome pretreatment reduced renal injury and the level of renal cell apoptosis in mice treated with renal ischemia/reperfusion injury.Moreover,this protective effect could be reversed by AMPK inhibitors.These findings verify that human umbilical cord mesenchymal stem cell-derived exosomes exerting a protective effect on renal ischemia/reperfusion injury may be related to the activation of the AMPK/YAP1 pathway to antiapoptosis.

Objective:To investigate the short-term and long-term effects of competency-oriented BOPPPS combined with scenario simulation teaching model on team emergency rescue skills training for healthcare professionals in Xizang.Methods:Forty-four healthcare professionals who participated in team emergency rescue training at Bianba People's Hospital from May 2022 to May 2023 were selected as study subjects. The BOPPPS combined with scenario simulation teaching model was applied in the clinical teaching of acute myocardial infarction. Before the training, the post competency was assessed using the Self-Directed Learning Instrument. The short-term teaching effects were evaluated using skill assessment and questionnaire after the training, and the long-term teaching effects were evaluated using the same questionnaire after six months.Results:Post-training skill assessment scores of the trainees were (50.45±6.68) for skill operation, (7.80±0.97) for humanistic communication, and (16.28±1.52) for team cooperation, which were significantly higher than pre-training scores ( P<0.05). Among self-directed learning abilities, "I enjoy finding answers to questions" was positively correlated with the humanistic communication scores, and "I can connect new knowledge with my personal experiences" was negatively correlated with skill operation scores ( P<0.05). The score of long-term emergency rescue skill improvement (4.27) was significantly higher than that after the training in the short term (3.98) ( P<0.05), while there were no significant decreases in career confidence and team collaboration ability ( P>0.05). Conclusions:The post competency-oriented BOPPPS combined with scenario simulation teaching model contributes to improving the team emergency rescue skills of healthcare professionals in Xizang, stabilizing their career confidence, and stimulating their self-learning ability. It is suitable to promote this teaching model in the clinical skills training of healthcare professionals in Xizang.

BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes are involved in multiple injury repair processes,and the effects and the specific mechanisms of renal ischemia/reperfusion injury have not been fully elucidated.OBJECTIVE:To investigate the molecular mechanism of human umbilical cord mesenchymal stem cell-derived exosomes in the treatment of renal ischemia/reperfusion injury.METHODS:(1) Human umbilical cord mesenchymal stem cells were cultured and exosomes were obtained and identified using an exosome extraction kit.(2) The distribution of exosomes in the kidney of mice with renal ischemia/reperfusion injury was examined by intravital fluorescence imaging.(3) Thirty C57/BL6 male mice were divided into five groups according to the random number table method:sham operation group,renal ischemia/reperfusion group,sham operation group+Compound C group,renal ischemia/reperfusion+exosome group (exosome group),and renal ischemia/reperfusion+exosome+Compound C group (exosome+Compound C group),with 6 mice in each group.Except the sham operation group,bilateral renal pedicles were clamped for 45 minutes and a mouse model of renal ischemia/reperfusion injury was established after 24 hours of reperfusion.In sham operation+Compound C group and exosome+Compound C group,AMPK inhibitor Compound C was intraperitoneally injected 30 minutes before model establishment.In the exosome group and exosome+Copmpound C group,exosomes were injected through the tail vein 15 minutes before renal pedicle clipping.The levels of serum creatinine and urea nitrogen,interleukin 6,and tumor necrosis factor α in renal tissue,and the expression of apoptosis-related factors in renal tissue were detected after 24 hours of reperfusion in each group.RESULTS AND CONCLUSION:(1) Human umbilical cord mesenchymal stem cell exosomes had the typical tea tray morphology,with the diameter distribution in the range of 40-160 nm,and expressed the specific marker membrane protein of exosome surface.(2) Murine kidneys after renal ischemia/reperfusion injury were more likely to gather human umbilical cord mesenchymal stem cell exosomes compared with the sham operation group.(3) Exosome pretreatment reduced renal injury and the level of renal cell apoptosis in mice treated with renal ischemia/reperfusion injury.Moreover,this protective effect could be reversed by AMPK inhibitors.These findings verify that human umbilical cord mesenchymal stem cell-derived exosomes exerting a protective effect on renal ischemia/reperfusion injury may be related to the activation of the AMPK/YAP1 pathway to antiapoptosis.

Objective:To investigate the short-term and long-term effects of competency-oriented BOPPPS combined with scenario simulation teaching model on team emergency rescue skills training for healthcare professionals in Xizang.Methods:Forty-four healthcare professionals who participated in team emergency rescue training at Bianba People's Hospital from May 2022 to May 2023 were selected as study subjects. The BOPPPS combined with scenario simulation teaching model was applied in the clinical teaching of acute myocardial infarction. Before the training, the post competency was assessed using the Self-Directed Learning Instrument. The short-term teaching effects were evaluated using skill assessment and questionnaire after the training, and the long-term teaching effects were evaluated using the same questionnaire after six months.Results:Post-training skill assessment scores of the trainees were (50.45±6.68) for skill operation, (7.80±0.97) for humanistic communication, and (16.28±1.52) for team cooperation, which were significantly higher than pre-training scores ( P<0.05). Among self-directed learning abilities, "I enjoy finding answers to questions" was positively correlated with the humanistic communication scores, and "I can connect new knowledge with my personal experiences" was negatively correlated with skill operation scores ( P<0.05). The score of long-term emergency rescue skill improvement (4.27) was significantly higher than that after the training in the short term (3.98) ( P<0.05), while there were no significant decreases in career confidence and team collaboration ability ( P>0.05). Conclusions:The post competency-oriented BOPPPS combined with scenario simulation teaching model contributes to improving the team emergency rescue skills of healthcare professionals in Xizang, stabilizing their career confidence, and stimulating their self-learning ability. It is suitable to promote this teaching model in the clinical skills training of healthcare professionals in Xizang.

Objective:To evaluate the role of nuclear factor E2-related factor 2 (Nrf2)/heme oxidase-1 (HO-1) in reduction of renal ischemia-reperfusion (I/R) injury by the human umbilical cord mesenchymal stem cells (hucMSCs)-derived exosomes (hucMSCs-exo) in mice.Methods:The hucMSCs were cultured, and exosomes were extracted and identified by transmission electron microscopy, nanoparticle tracking analysis and Western blot. Thirty-six male SPF-grade C57BL/6 mice, weighing 20-25 g, were used. Thirty mice were selected and divided into 5 groups ( n=6 each) by a random number table method: sham operation group (Sham group), sham operation + Nrf2 inhibitor ML385 group (Sham + ML385 group), renal I/R group (I/R group), renal I/R + exosome group (I/R+ EXO group), and renal I/R + exosome + Nrf2 inhibitor ML385 group (I/R+ EXO+ ML385 group). A model of renal I/R injury was prepared by clamping the bilateral renal pedicles for 45 min followed by perfusion in anesthetized animals. ML385 30 mg/kg was intraperitoneally injected at 45 min before preparing the model in Sham+ ML385 group and I/R+ EXO+ ML385 group, and hucMSCs-exo 100 μg was injected via the tail vein at 15 min before reperfusion in I/R+ EXO group and I/R+ EXO+ ML385 group. Serum blood urea nitrogen (BUN) and creatinine (Cr) concentrations were detected at 24 h of reperfusion. The renal tissues were obtained for examination of the pathological changes and for determination of contents of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA), superoxide dismutase (SOD) activity and reactive oxygen species (ROS) levels and expression of Nrf2 and HO-1 protein and mRNA (by Western blot and quantitative real-time polymerase chain reaction). The left 6 mice were allocated to sham operation group (Sham-IM group, n=3) and renal I/R group (I/R-IM group, n=3) by a random number table method for VISQUE in living imaging observation. Results:The exosomes showed a typical cup-shaped morphology with a transmission electron microscope, the nanoparticles tracked and analyzed the average diameter of the exosome, with an average diameter of 96.7 nm, and the positive expression of surface markers CD9, CD63 and TSG101 was detected using Western blot. The renal fluorescence intensity value was significantly increased in I/R-IM group as compared with Sham-IM group ( P<0.05). Compared with Sham group, the serum BUN and Cr concentrations were significantly increased, the contents of IL-6, TNF-α and MDA and ROS levels were increased, the activity of SOD was decreased, the expression of Nrf2 and HO-1 protein and mRNA was down-regulated ( P<0.05), and the pathological changes of renal tissues were aggravated in I/R group, and no significant change was found in serum BUN and Cr concentrations in Sham+ ML385 group ( P>0.05). Compared with I/R group, the serum BUN and Cr concentrations were significantly decreased, the contents of IL-6, TNF-α and MDA and ROS levels were decreased, the activity of SOD was increased, the expression of Nrf2 and HO-1 protein and mRNA was up-regulated ( P<0.05), and the pathological changes of renal tissues were significantly attenuated in I/R+ EXO group. Compared with I/R+ EXO group, the serum BUN and Cr concentrations were significantly increased, the contents of IL-6, TNF-α and MDA and ROS levels were increased, the activity of SOD was decreased, the expression of Nrf2 and HO-1 protein and mRNA was down-regulated ( P<0.05), and the pathological changes of renal tissues were aggravated in I/R+ EXO+ ML385 group. Conclusions:The mechanism by which hucMSCs-exo reduces renal I/R injury may be related to activation of the Nrf2/HO-1 signaling pathway in mice.

Objective:To explore the applied therapeutic effect of digital surgical technique combined with three dimensional(3D)printing guide plate in surgery of maxillofacial fracture.Methods:A total of forty patients with maxillofacial fracture who admitted to the Department of Stomatology at the First Medical Center of Chinese PLA General Hospital from June 2019 to June 2023 were selected.They were divided into an observation group(18 cases)and a control group(22 cases)based on different surgical methods.The observation group used digital technique combined with 3D printing technique to conduct surgery by auxiliary method,and the control group used routine open reduction and internal fixation surgery for maxillofacial fracture.The surgical time,bleeding volume,complications and satisfaction evaluation between two groups of patients were observed and compared.Results:All patients obtained clinical cure after open reduction and internal fixation surgery,and the surgical time(2.01±0.52)h and bleeding volume(123.89±67.31)mL during surgery of observation group were significantly lower than those of control group(U=62.000,26.500,P<0.05),respectively.The incidence of the complications in the observation group was significantly lower than that in the control group,and the difference was statistically significant(x2=4.675,P<0.05),and there were no statistically significant difference in infection and limited incision opening between the two groups(P>0.05).In the satisfaction evaluation,there was a significant difference in appearance satisfaction scores between the observation group(8.89±0.758)and the control group(7.73±0.827)(U=66.000,P<0.05),while there were no statistically significant differences in chewing and language aspects between two groups(P>0.05).Conclusion:The combination of digital technique and 3D printing guide plate has favorable clinical guidance effect in maxillofacial fracture surgery,which can significantly improve surgical efficacy,and reduce the incidence of complications,and obtain higher patient satisfaction.It is worth to be applied in clinical practice.