1.A reporter gene assays for bioactivity determination of human chorinonic gonadotropin
Ying HUANG ; Xiao-ming ZHANG ; He-yang LI ; Lü-yin WANG ; Hui ZHANG ; Ping LÜ ; Jing LI ; Xiang-dong GAO ; Cheng-gang LIANG
Acta Pharmaceutica Sinica 2024;59(2):432-438
		                        		
		                        			
		                        			 This study constructed a LHCGR-CRE-luc-HEK293 transgenic cell line according to the activation of the cAMP signaling pathway after recombinant human chorionic gonadotropin binding to the receptor. The biological activity of recombinant human chorionic gonadotropin was assayed using a luciferase assay system. The relative potency of the samples was calculated using four-parameter model. And the method conditions were optimized to validate the specificity, relative accuracy, precision and linearity of the method. The results showed that there was a quantitative potency relationship of human chorinonic gonadotropin (hCG) in the method and it was in accordance with the four-parameter curve. After optimization, the conditions were determined as hCG dilution concentration of 2.5 μg·mL-1, dilution ratio of 1∶4, cell number of 10 000-15 000 cells/well, and induction time of 6 h. The method had good specificity, relative accuracy with relative bias ranging from -8.9% to 3.4%, linear regression equation correlation coefficient of 0.996, intermediate precision geometric coefficient of variation ranging from 3.3% to 15.0%, and linearity range of 50% to 200%. This study successfully established and validated a reporter gene method to detect hCG biological activity, which can be used for hCG biological activity assay and quality control. 
		                        		
		                        		
		                        		
		                        	
2.Effect of pulmonary surfactant combined with budesonide in improving oxygenation and clinical outcomes in neonatal acute respiratory distress syndrome
Yi-Yang LIU ; Rong ZHANG ; Shuai ZHAO ; Lan KANG ; Xiao-Ping LEI ; Wen-Bin DONG
Medical Journal of Chinese People's Liberation Army 2024;49(3):259-264
		                        		
		                        			
		                        			Objective To explore the role of pulmonary surfactant(PS)combined with budesonide in improving oxygenation and clinical outcomes of neonatal acute respiratory distress syndrome(ARDS).Methods The present study is a historically controlled trial.Infants with ARDS requiring mechanical ventilation and PS replacement therapy were collected from the neonatal unit of Southwest Medical University.Those from January 2022 to November 2022 were set as intervention group(PS+ budesonid,n=35),treated with intratracheal instillation of a mixed suspension of budesonide(0.25 mg/kg)and PS(200 mg/kg),and continuous budesonide nebulization(0.25 mg/kg,twice per day)until withdrawal,then compared with a historical cohort,who just received intratracheal instillation of PS(200 mg/kg)(January 2020-December 2021,PS group,n=35).Baseline data such as gender,mode of delivery,1 min and 5 min Apgar score,birth weight,gestational age,time of onset,and cause of onset were recorded in both groups.The oxygenation and clinical outcomes of infants were compared between the two groups,including:(1)Arterial blood gas analysis indicators,such as partial pressure of oxygen(PaO2)and oxygenation index(OI)before treatment and at 6,12 and 24 hours of treatment;(2)Clinical observation and evaluation indicators,such as the time to withdrawal,duration of oxygen supplementation,length of stay,improvement of the radiological images of the lungs at 72 h of treatment,and repeated PS use;(3)Blood chemistry indicators,such as white blood cell(WBC),neutrocyte(NEU),procalcitonin(PCT)before treatment and at 3 and 7 days of treatment;and(4)Observation indicators of complications,weight growth,and mortality outcomes,such as the incidences of intracranial hemorrhage,gastrointestinal hemorrhage,neonatal necrotizing enterocolitis(NEC),and hyperglycemia,weight growth,and fatality rate.Results The differences in baseline data between the two groups were not statistically different(P>0.05).The levels of PaO2 of the two groups were increased after treatment for different time periods,while the levels of OI were decreased(P<0.001),and the levels of above indexes changed more significantly in PS+budesonide group than those in PS group(P<0.05).The time to withdrawal,duration of oxygen supplementation,and length of stay in PS+budesonide group were shorter than those in PS group;the radiological images of the lungs showed that the pulmonary inflammation absorption was significantly better in PS+ budesonide group than that in PS group,while no significant difference between the two groups of infants with repeated PS use.The NEU was significantly higher in PS+budesonide group than in PS group at 3 d and 7 d of treatment(P<0.001);and at 3 days of treatment,the PCT levels were significantly lower in PS+budesonide group than that in PS group(P<0.05).The incidences of intracranial hemorrhage,gastrointestinal hemorrhage,NEC,hyperglycemia,weight growth,and fatality rate were not significantly different between the two groups(P>0.05).Conclusion The use of budesonide in addition to surfactant may improve the oxygenation of neonates with ARDS,improve the inflammatory infiltrates in lungs,shorten the duration of mechanical ventilation and oxygen supplementation,and without short-term complications associated with budesonide use.
		                        		
		                        		
		                        		
		                        	
3.Correction between hand hygiene product consumption and hand hygiene compliance in intensive care units of 74 medical institutions in Shanghai
Hong-Ping PAN ; Meng-Ge HAN ; Qing-Feng SHI ; Bi-Jie HU ; Xiao-Dong GAO
Chinese Journal of Infection Control 2024;23(3):291-297
		                        		
		                        			
		                        			Objective To understand the consumption of hand hygiene(HH)products and HH compliance in in-tensive care units(ICUs)of secondary and higher grade medical institutions(MIs)in Shanghai,and provide basis for further monitoring of HH among health care workers(HCWs).Methods Through healthcare-associated infec-tion surveillance system,the consumption of HH products and HH compliance in ICUs from secondary and higher grade MIs in Shanghai in 2017-2021 were analyzed.Results 105 ICUs from 74 MIs were included in analysis,the average consumption of HH products was 79.24(44.88-258.63)mL/(bed·day),with statistically significant difference among different types of ICUs(P<0.001).The average consumption of HH products increased from 65.75 mL/(bed·day)in 2017 to 87.55 mL/(bed·day)in 2021,showing an increasing trend year by year(P<0.001).HCWs'HH compliance rate was 82.13%,with the highest in nurses(86.59%)and the lowest(48.90%)in medical technicians,HH compliance rates of HCWs of different occupations were statistically significant different(P<0.001).Among the implementation modes of HH,39.86%used running water for hand washing,42.27%used alcohol-based hand rub to wipe hands,13.22%didn't take HH measures,and 4.65%didn't take HH mea-sures when wearing gloves,with statistically significant differences among different HH implementation modes of HCWs(P<0.001).There was a positive correlation between the average consumption of HH products per bed·day and HCWs'HH compliance rate(r=0.703,P<0.05).Conclusion The average consumption of HH products per bed·day and HH compliance rate of HCWs in ICUs in Shanghai presents an increasing trend year by year.There are differences in the average consumption of HH products per bed·day and HH compliance rate among different types of ICUs.The implementation of HH can be evaluated by continuously surveillance on the average consumption of HH products per bed·day.
		                        		
		                        		
		                        		
		                        	
4.National bloodstream infection bacterial resistance surveillance report (2022) : Gram-negative bacteria
Zhiying LIU ; Yunbo CHEN ; Jinru JI ; Chaoqun YING ; Qing YANG ; Haishen KONG ; Haifeng MAO ; Hui DING ; Pengpeng TIAN ; Jiangqin SONG ; Yongyun LIU ; Jiliang WANG ; Yan JIN ; Yuanyuan DAI ; Yizheng ZHOU ; Yan GENG ; Fenghong CHEN ; Lu WANG ; Yanyan LI ; Dan LIU ; Peng ZHANG ; Junmin CAO ; Xiaoyan LI ; Dijing SONG ; Xinhua QIANG ; Yanhong LI ; Qiuying ZHANG ; Guolin LIAO ; Ying HUANG ; Baohua ZHANG ; Liang GUO ; Aiyun LI ; Haiquan KANG ; Donghong HUANG ; Sijin MAN ; Zhuo LI ; Youdong YIN ; Kunpeng LIANG ; Haixin DONG ; Donghua LIU ; Hongyun XU ; Yinqiao DONG ; Rong XU ; Lin ZHENG ; Shuyan HU ; Jian LI ; Qiang LIU ; Liang LUAN ; Jilu SHEN ; Lixia ZHANG ; Bo QUAN ; Xiaoping YAN ; Xiaoyan QI ; Dengyan QIAO ; Weiping LIU ; Xiusan XIA ; Ling MENG ; Jinhua LIANG ; Ping SHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2024;17(1):42-57
		                        		
		                        			
		                        			Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System(BRICS)were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute(CLSI). WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period,9 035 strains of Gram-negative bacteria were collected from 51 hospitals,of which 7 895(87.4%)were Enterobacteriaceae and 1 140(12.6%)were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli( n=4 510,49.9%), Klebsiella pneumoniae( n=2 340,25.9%), Pseudomonas aeruginosa( n=534,5.9%), Acinetobacter baumannii complex( n=405,4.5%)and Enterobacter cloacae( n=327,3.6%). The ESBLs-producing rates in Escherichia coli, Klebsiella pneumoniae and Proteus spp. were 47.1%(2 095/4 452),21.0%(427/2 033)and 41.1%(58/141),respectively. The prevalence of carbapenem-resistant Escherichia coli(CREC)and carbapenem-resistant Klebsiella pneumoniae(CRKP)were 1.3%(58/4 510)and 13.1%(307/2 340);62.1%(36/58)and 9.8%(30/307)of CREC and CRKP were resistant to ceftazidime/avibactam combination,respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)complex was 59.5%(241/405),while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa(CRPA)was 18.4%(98/534). There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions,with statistically significant differences in the prevalence of CRKP and CRPA( χ2=20.489 and 20.252, P<0.001). The prevalence of CREC,CRKP,CRPA,CRAB,ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals( χ2=11.953,81.183,10.404,5.915,12.415 and 6.459, P<0.01 or <0.05),while the prevalence of CRPA was higher in economically developed regions(per capita GDP ≥ 92 059 Yuan)than that in economically less-developed regions(per capita GDP <92 059 Yuan)( χ2=6.240, P=0.012). Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend,and Escherichia coli is ranked in the top,while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different,and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.
		                        		
		                        		
		                        		
		                        	
5.Preparation of soluble microneedles of Aconitum brachypodum alkaloids
Yao CHEN ; Bi-Li DENG ; Jing WAN ; Na-Na DONG ; Xiao-Lan CHEN ; Yong-Ping ZHANG
Chinese Traditional Patent Medicine 2024;46(3):740-747
		                        		
		                        			
		                        			AIM To prepare the soluble microneedles of Aconitum brachypodum Diels alkaloids.METHODS Centrifugal molding method was adopted in the preparation of soluble microneedles.With chondroitin sulfate consumption,PVP K120 consumption and 40%ethanol consumption as influencing factors,piercing rate as an evaluation index,the formulation was optimized by Box-Behnken response surface method,after which the morphology,piercing performance,drug content and in vitro transdermal performance were investigated.RESULTS The optimal formulation was determined to be 123 mg for chondroitin sulfate consumption,298 mg for PVP K120 consumption,and 2.4 mL for 40%ethanol consumption,the piercing rate was 98.3%.The soluble microneedles were yellow and square patch with conoid needle,which could pierce aluminum foil and rat skin,along with the drug content of(0.94±0.025)mg.The soluble microneedle group demonstrated the accumulative permeability rate of 91.4%within 24 h,which was higher than that in the gel ointment group,and the permeability accorded with Higuchi equation.CONCLUSION The soluble microneedles of A.brachypodum alkaloids exhibit good mechanical strength,which can achieve effective transdermal delivery of drugs.
		                        		
		                        		
		                        		
		                        	
6.Arthroscopic surgery for injuries to the popliteal tendon area of the lateral meniscus
Ming-Tao ZHANG ; Zhi-Tao YANG ; Tao LIU ; Bo-Rong ZHANG ; Xiao-Yi TAN ; Jin JIANG ; Li-Ping AN ; Xiang-Dong YUN
China Journal of Orthopaedics and Traumatology 2024;37(7):713-717
		                        		
		                        			
		                        			Objective To investigate the mid-term effect and complications of arthroscopic popliteal tendon suture in the treatment of lateral meniscus injury.Methods From January 2016 to December 2020,the data of 57 patients with lateral meniscus popliteal tendon injury treated by arthroscopic popliteal tendon suture fixation were retrospectively analyzed,includ-ing 35 males and 22 females,aged from 18 to 47 years old with an average of(32.9±7.9)years old.Knee function was evaluat-ed using the International Knee Documentation Committee(IKDC)and Lysholm scores both before the operation and at the fi-nal follow-up.Meniscus healing was evaluated according to the postoperative Barrett standard.Wound healing complications,such as vascular injury,nerve injury,and lower extremity venous thrombosis,were recorded.Results All 57 patients were fol-lowed up for 12 to 58 months with an average of(38.1±14.9)months.The incisions of the patients after the operation were all Grade A healing without infection,popliteal tendon injury,blood vessel injury,nerve injury and lower extremity venous throm-bosis.The IKDC score increased from(49.7±3.6)points preoperatively to(88.5±4.4)points in the final follow-up(P<0.05).The Lysholm score increased from(48.8±4.9)points preoperatively to(91.9±3.9)points at the final follow-up(P<0.05).At 3,6 months and 1 year after operation,according to Barrett's criteria,54 cases were clinically healed,the healing rate was 94.7%(54/57).Conclusion This study preliminarily confirmed that arthroscopic suture technique can result in clinical sta-bility through suture and fixation of the meniscus in the injured lateral popliteal tendon area.No adverse effects on knee joint function were found in the mid-term follow-up after the operation.
		                        		
		                        		
		                        		
		                        	
7.The cytochrome P4501A1 (CYP1A1) inhibitor bergamottin enhances host tolerance to multidrug-resistant Vibrio vulnificus infection
Ruo-Bai QIAO ; Wei-Hong DAI ; Wei LI ; Xue YANG ; Dong-Mei HE ; Rui GAO ; Yin-Qin CUI ; Ri-Xing WANG ; Xiao-Yuan MA ; Fang-Jie WANG ; Hua-Ping LIANG
Chinese Journal of Traumatology 2024;27(5):295-304
		                        		
		                        			
		                        			Purpose::Vibrio vulnificus ( V. Vulnificus) infection is characterized by rapid onset, aggressive progression, and challenging treatment. Bacterial resistance poses a significant challenge for clinical anti-infection treatment and is thus the subject of research. Enhancing host infection tolerance represents a novel infection prevention strategy to improve patient survival. Our team initially identified cytochrome P4501A1 (CYP1A1) as an important target owing to its negative modulation of the body's infection tolerance. This study explored the superior effects of the CYP1A1 inhibitor bergamottin compared to antibiotic combination therapy on the survival of mice infected with multidrug-resistant V. Vulnificus and the protection of their vital organs. Methods::An increasing concentration gradient method was used to induce multidrug-resistant V. Vulnificus development. We established a lethal infection model in C57BL/6J male mice and evaluated the effect of bergamottin on mouse survival. A mild infection model was established in C57BL/6J male mice, and the serum levels of creatinine, urea nitrogen, aspartate aminotransferase, and alanine aminotransferase were determined using enzyme-linked immunosorbent assay to evaluate the effect of bergamottin on liver and kidney function. The morphological changes induced in the presence of bergamottin in mouse organs were evaluated by hematoxylin and eosin staining of liver and kidney tissues. The bacterial growth curve and organ load determination were used to evaluate whether bergamottin has a direct antibacterial effect on multidrug-resistant V. Vulnificus. Quantification of inflammatory factors in serum by enzyme-linked immunosorbent assay and the expression levels of inflammatory factors in liver and kidney tissues by real-time quantitative polymerase chain reaction were performed to evaluate the effect of bergamottin on inflammatory factor levels. Western blot analysis of IκBα, phosphorylated IκBα, p65, and phosphorylated p65 protein expression in liver and kidney tissues and in human hepatocellular carcinomas-2 and human kidney-2 cell lines was used to evaluate the effect of bergamottin on the nuclear factor kappa-B signaling pathway. One-way ANOVA and Kaplan-Meier analysis were used for statistical analysis. Results::In mice infected with multidrug-resistant V. Vulnificus, bergamottin prolonged survival ( p = 0.014), reduced the serum creatinine ( p = 0.002), urea nitrogen ( p = 0.030), aspartate aminotransferase ( p = 0.029), and alanine aminotransferase ( p = 0.003) levels, and protected the cellular morphology of liver and kidney tissues. Bergamottin inhibited interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α expression in serum (IL-1β: p = 0.010, IL-6: p = 0.029, TNF-α: p = 0.025) and inhibited the protein expression of the inflammatory factors IL-1β, IL-6, TNF-α in liver (IL-1β: p = 0.010, IL-6: p = 0.011, TNF-α: p = 0.037) and kidney (IL-1β: p = 0.016, IL-6: p = 0.011, TNF-α: p = 0.008) tissues. Bergamottin did not affect the proliferation of multidrug-resistant V. Vulnificus or the bacterial load in the mouse peritoneal lavage fluid ( p = 0.225), liver ( p = 0.186), or kidney ( p = 0.637). Conclusion::Bergamottin enhances the tolerance of mice to multidrug-resistant V. Vulnificus infection. This study can serve as a reference and guide the development of novel clinical treatment strategies for V. Vulnificus.
		                        		
		                        		
		                        		
		                        	
8.Disease characteristics and costs of pediatric Mycoplasma Pneumoniae pneumonia hospitalization:a retrospective study at municipal hospitals from 2019 to 2023 in Shanghai
Ying-Wen WANG ; Feng WANG ; Li-Bo WANG ; Ai-Zhen LU ; Yi WANG ; Yong-Hao GUI ; Quan LU ; Yong YIN ; Jian-Hua ZHANG ; Ying-Zi YE ; Hong XU ; Bing SHEN ; Dan-Ping GU ; Xiao-Yan DONG ; Jia-Yu WANG ; Wen HE ; Xiao-Bo ZHANG
Fudan University Journal of Medical Sciences 2024;51(4):515-521
		                        		
		                        			
		                        			Objective To investigate disease characteristics and hospitalization costs of children with Mycoplasma Pneumoniae pneumonia(MPP)admitted to Shanghai municipal medical hospitals from 2019 to 2023.Methods Depending on the Shanghai Municipal Hospital Pediatric Alliance,we retrospectively investigated community acquired MPP pediatric patients hospitalized in 22 municipal hospitals with pediatric qualifications(including 4 children's hospitals)in Shanghai from Jan 2019 to Dec 2023.We collected the patients'diagnosis codes,gender,age,length of hospital stay,hospitalization costs,and whether they progressed to severe Mycoplasma pneumoniae pneumonia(SMPP).Results From 2019 to 2023,a total of 29 045 hospitalized children with MPP were treated,with 6 035 cases(20.8%)identified as SMPP in the 22 hospitals.Trend analysis revealed a rising trend with years in the proportion of SMPP patients(χ2trend=365.498,P<0.001).Among the 4 children's hospitals,there were 18 710 cases with MPP,including 4 078 cases(21.8%)of SMPP.The proportion of SMPP patients also showed an increasing trend with years(χ2trend=14.548,P<0.001),and the proportion in 2023(23.0%)was higher than that in previous years with statistical significance.There were statistical differences in the seasonal distribution of MPP cases between different years,with higher proportions in summer and autumn overall.The age distribution of hospitalized MPP children varied among different years,with school-age children accounting for the majority(56.8%)in 2023.There was no difference in the distribution of severe cases between different genders,but there were differences in the proportion of severe cases among different age groups in different years,with a gradual increase in severe cases among children aged 1 to 3 years(χ2trend=191.567,P<0.001).The average length of hospital stay for MPP during the epidemic was higher than that during non-epidemic periods,and there were statistically significant differences in the average length of hospital stay between different years(P<0.001).The individual hospitalization costs during the epidemic were higher than in other years,and there were statistically significant differences in individual hospitalization costs between different years(P<0.001).The total hospitalization costs were still higher in 2019 and 2023.The individual hospitalization costs for SMPP were higher than for non-SMPP cases.Conclusion MPP outbreaks occurred in Shanghai in 2019 and 2023,with the higher proportions in summer and autumn overall.Compared to previous years,the number of hospitalized MPP children in Shanghai was higher in 2023,with a higher proportion of SMPP cases,especially among children under 3 years old.The individual per capita hospitalization expenses for SMPP cases were higher than for non-SMPP cases.
		                        		
		                        		
		                        		
		                        	
9.Association of abnormal early postoperative blood glucose concentration with short-term prognosis and establishment of a prediction model in patients undergoing non-small cell lung cancer surgery
Gang ZHONG ; Nian-Ping MO ; Zheng-Yao YANG ; Tao JIANG ; Dong-Fang TANG ; Xiao-Yong SHEN
Fudan University Journal of Medical Sciences 2024;51(6):949-956
		                        		
		                        			
		                        			Objective To investigate the effect of early postoperative abnormal blood glucose on the short-term prognosis of non-small cell lung cancer(NSCLC),and to analyze the clinical characteristics and risk factors related to poor early prognosis.Methods A total of 897 patients with NSCLC who underwent thoracoscopic surgery in Huadong Hospital,Fudan University from Jan 2020 to Aug 2021 were divided into hyperglycemia(HG)group(>7.8 mmol/L)and normal blood glucose(NG)group(≤7.8 mmol/L and≥3.9 mmol/L)according to the early postoperative blood glucose values.Additionally,the patients were divided into higher blood glucose fluctuation group(≥4 mmol/L)and the group with lower blood glucose fluctuation(<4 mmol/L)basing on the fasting blood glucose.Using Logistic regression models,column line charts,ROC curves and other methods,we aimed to clarify the impact of early postoperative blood glucose abnormalities on short-term prognosis,explore clinical characteristics associated with poor short-term outcomes,identify other high-risk factors,and establish relevant risk prediction models.Results Compared with the NG group,the incidence of postoperative pneumonia,thromboembolism,ICU admission rate,total length of hospital stay and hospital cost were significantly higher in the HG group(P<0.05).Higher blood glucose fluctuation group had a greater risk of ICU admission(P=0.003).Logistic regression analysis showed that age,preoperative fasting glucose,white blood cell count and cytokeratin 19 fragment antigen 21-1(CYFRA21-1)were risk factors for postoperative hyperglycemia(P<0.05).Contrary to the effect of BMI,diabetes,male patients,higher blood glucose fluctuation,white blood cell count and age were the risk factors for postoperative adverse events(P<0.05).The AUC of the column line chart model was 0.661(95%CI:0.624-0.698),indicating good discriminative ability for predicting poor short-term prognosis postoperatively.Calibration curves also demonstrated good consistency between predicted and actual probabilities.Conclusion Early postoperative blood glucose fluctuations independently impact the short-term prognosis of thoracoscopic NSCLC patients.Blood glucose combined with gender,BMI,white blood cell count,age and diabetes history can serve as predictive factors for poor short-term prognosis postoperatively.Additionally,a column line chart constructed based on these factors may aid clinicians in early intervention for NSCLC patients with indications.
		                        		
		                        		
		                        		
		                        	
10.Effect and mechanism of proteasome inhibitor MG132 on memory impairment caused by chronic hypoxia in mice
Hua-Ping DONG ; Peng LI ; Xiao-Xu LI ; Si-Min ZHOU ; Heng XIAO ; Jia-Xin XIE ; Pei HUANG ; Yu WU ; Zhi-Feng ZHONG
Medical Journal of Chinese People's Liberation Army 2024;49(4):449-458
		                        		
		                        			
		                        			Objective To investigate the effect and mechanism of proteasome inhibitor MG132 on memory impairment induced by chronic hypoxia in mice.Methods(1)A hypoxic model of the mouse midbrain dopaminergic neuron cell line MN9D was established using a hypoxia workstation.To observe the effects of hypoxia on the expression of TH,Ub-K48 and Ub-K63,MN9D cells were divided into normoxia group and hypoxia(12 h,24 h and 48 h)groups.To observe the effects of MG132 on the expression of the above-mentioned proteins,MN9D cells were divided into normoxia group,hypoxia group and hypoxia + MG132(25,50,100,200 μmol/L)group.(2)A mouse model of memory impairment was established using a hypobaric chamber.To observe the effects of hypobaric hypoxia on the expression of TH,Ub-K48 and Ub-K63 in the substantia nigra compacta(SNc)of mice,thirty C57BL/6 mice were randomly and equally divided into normoxia group and hypobaric hypoxia(3 d and 21 d)groups,10 in each group.To observe the effects of MG132 on spatial memory impairment induced by hypobaric hypoxia,twenty-four C57BL/6 mice were randomly and equally divided into normoxia group,hypobaric hypoxia 21 d group and hypobaric hypoxia 21 d+MG132 group,8 in each group.(3)The protein expression levels of TH,Ub-K48,and Ub-K63 in MN9D cells which were either subjected to different durations of hypoxia treatment or pre-treated with MG132 prior to hypoxia treatment were detected using Western blotting(WB).The novel object recognition test was used to detect the memory function of mice.Immunofluorescence was used to detect the proportion of positive immunoreactive area of TH response in the SNc region.The expression levels of TH,Ub-K48,and Ub-K63 in the SNc region were detected by WB.Results(1)Compared with normoxia group,MN9D cells in hypoxia 24 h group showed increasing expression of Ub-K48 and Ub-K63(P<0.05),and decreasing expression of TH(P<0.05),and MN9D cells in all hypoxia groups showed increasing expression of Ub-K48/TH and Ub-K63/TH(P<0.05).Compared with hypoxia group,MN9D cells showed decreasing expression of Ub-K48/TH and Ub-K63/TH in hypoxia + MG132 100 umol/L group and hypoxia + MG132 200 umol/L group(P<0.05).(2)Compared with the mice in normoxia group,mice in 3 d and 21 d hypobaric hypoxia groups showed decreasing expression of TH(P<0.001),and increasing expression of Ub-K48/TH and Ub-K63/TH(P<0.05)in the SNc region.Compared with normoxia group,the mice in 21 d hypobaric hypoxia group showed a lower new object recognition index(P<0.01),and the proportion of positive immunoreactive area of TH response in the SNc region(P<0.05).Compared with 21 d hypobaric hypoxia group,the mice in hypobaric hypoxia 21 d+MG132 group showed a higher new object recognition index(P<0.01).Conclusion The proteasome inhibitor MG132 could alleviate the memory impairment induced by chronic hypoxia in mice,and its mechanism may be related to the inhibition of Ub-K63 and Ub-K48,which in turn upregulates expression of TH in dopaminergic neurons.
		                        		
		                        		
		                        		
		                        	
            
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