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Objective@#To investigate whether GIV , a coiled helix structural domain protein containing 88A , has an effect on the neuroinflammatory response in a model of cerebral ischemia⁃reperfusion injury.@*Methods@# A middle cerebral artery embolization⁃reperfusion model (MACO/R) and an oxygen glucose deprivation/reoxygenation model ( OGD 6 h + R 24 h) of BV2 microglia were constructed in C57BL/6 mice , and the area of cerebral infarction was detected by TTC staining; the Longa neurobiological score was used to evaluate the degree of neurological deficit in mice ; ELISA was used to detect the release of IL⁃6 and TNF⁃α in the supernatant of peripheral blood and cell cultures , and Western blot was used to detect the protein expression of GIV , TREM2 and TLR4 in the cortical area around the infarct foci in mice ; different concentrations of lipopolysaccharide (LPS , 1 , 5 , 10 μg/ml) were used to stimulate BV2 cells for 24 h to establish a neuroinflammation model , qRT⁃PCR was performed to detect the mRNA levels of IL⁃6 , TNF⁃α and IL⁃1β , and Western blot was used to detect the expression of GIV ; OGD/R culture treatment was performed after knocking down the expression of GIV gene using siRNA interference technique ;ELISA was performed to detect the release concentration of IL⁃6 and TNF⁃α in cell culture medium supernatant;protein immunoblotting was performed to detect the knockdown efficiency of GIV.@*Results @#Both the successfully constructed MCAO/R and OGD/R models activated the neuroinflammatory response and induced a decrease in protein expression of GIV ; MCAO/R induced increased concentrations of IL⁃6 and TNF⁃α release in peripheral blood of mice and promoted the protein expression of TREM2 and TLR4 ; LPS activated IL⁃6 , IL⁃1β and TNF⁃α expression in BV2 cells , but did not affect GIV expression ; siRNA interference with GIV gene expression further in creased the expression of inflammatory factors IL⁃6 and TNF⁃α .@*Conclusion@#The GIV gene may be characteristically involved in regulating the neuroinflammatory response induced by cerebral ischemia⁃reperfusion injury , and it may be a potential therapeutic target for cerebral ischemia⁃reperfusion injury.
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Objective @# To explore the role of Argonaute ( Ago) gene and RNA⁃Dependent RNA Polymerase (RDRP) gene of Aspergillus flavus in the growth and development about the RNAi mechanism . @*Methods @# A. flavus Ago1 , Ago2 , RDRP1 , RDRP3 gene mutant strains were constructed by homologous recombination . The growth and development of the mutant strains were observed on potato dextrose agar(PDA) + uracil uridine (UU) medium inoculated with 3 μl 106 CFU/mL spores . 200 , 400 μg cell wall pressure agent conidored ( CR) , 0. 8 mol/L , 1 . 6 mol/L osmotic pressure agent NaCl , 2 mmol/L , 4 mmol/L oxidative pressure agent hydrogen peroxide (H2 O2 ) and 0. 01% , 0. 02% genomic damage agent methyl mesylate (MMS) were added to the Yeast extract Glucose Minimum (YGM) + UU medium to analyze the stress response of the mutant strains . @*Results @#A. flavus mutant strains about ΔAgo1 , ΔAgo2 , ΔRDRP1 , ΔRDRP3 were successfully constructed and its growth and development were normal . The ΔAgo1 and ΔAgo2 strains reduced the stress effects on cell wall and osmotic pressure compared to the control . Ago1 gene deletion reduced the effect of H2 O2 , and conversely RDRP3 gene deletion increased the inhibition of H2 O2 . The Ago2 and RDRP1 strains reduced the effect on genetic damage agent . In addition , ΔRDRP1 increased the effect of osmotic stress . @*Conclusion @# The Ago1 , Ago2 , RDRP1 and RDRP3 genes of A. flavus are not in⁃ volved in the regulation of growth rate and asexual reproduction and can participate in the regulating of the host stress response to the environment .
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Objective:To explore the effect of the enriched environment(EE)on pyroptosis in rats with cerebral ischemia-reperfusion injury(CIRI).Methods:45 male Sprague-Dawley rats were randomly divided into three groups: a sham surgery(Sham)group, a cerebral ischemia-reperfusion(CIR)group and an enriched environment(EE)group, with 15 rats in each group.Except for the Sham group, the right middle cerebral artery occlusion model was established in the other two groups.After surgery, the EE group was fed in EE, and the other two groups were fed in standard environment.All the rats were assessed using the modified neurological severity score(mNSS)before modeling and on the 1st day, 7th day and 14th day following surgery.On the 14th day after surgery, 2, 3, 5-triphenyltetrazolium chloride(TTC)staining was used to evaluate the infarct volume, hematoxylin and eosin(HE)staining was used to examine pathomorphological changes of the hippocampal CA1 region on the ischemic side of the rats in each group, immunohistochemical assay was used to detect the expression of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)and cysteinyl aspartate specific proteinase-1(caspase-1)proteins in the CA1 region, and ultrastructural changes in neurons in the CA1 region were observed under transmission electron microscopy.Results:Compared with the Sham group, the mNSS scores of the CIR group and the EE group were significantly higher on the 1st day and 7th day after surgery( P<0.05), but there was no significant difference between the CIR and EE groups( P>0.05). On the 14th day after surgery, compared with the CIR group, the EE group showed a decrease in the mNSS score and the cerebral infarct volume( P<0.05), alleviated pathomorphological changes, decreased expression of NLRP3 and caspase-1 proteins( P<0.05), and alleviated pathological changes of pyroptosis in the ultrastructure of neurons. Conclusions:EE can reduce the damage of neurological function, reduce the cerebral infarct volume, and play a protective role for the brain in CIRI rats.The mechanism may be related to the down-regulation of the expression of NLRP3 and caspase-1 proteins related to the classical pyroptosis pathway, leading to the inhibition of pyroptosis.
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【Objective】 To investigate the effects and mechanism of STAT3 inhibitor Stattic combined with arsenic trioxide (ATO) on the survival and apoptosis of acute myeloid leukemia (AML) THP1 cells. 【Methods】 CCK8 assay was used to detect the effects of Stattic combined with ATO on cell viability, flow cytometry was used to detect cellular apoptosis and ROS levels, and Caspase 3/7 Glo assay was used to determine Caspase 3/7 activity. qPCR was used to detect mRNA expression levels of GCLM, GCLC and HO-1 genes, and Western blotting was used to detect protein expression levels of P-STAT3, STAT3 and Nrf2. 【Results】 Stattic significantly inhibited the level of phosphorylated STAT3, aggravated the inhibitory effect of ATO on THP1 cell viability, and enhanced the apoptosis and reactive oxygen species (ROS) induced by ATO. Stattic significantly inhibited the expression of ATO-upregulated Nrf2 and the expression of Nrf2 downstream genes including HO-1, GCLM and GCLC. 【Conclusion】 Stattic can enhance the effects of ATO-mediated viability inhibition and apoptosis. The mechanism may be related to the increased ROS via inhibition of Nrf2 and Nrf2 downstream gene expression.
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BACKGROUND@#After general thoracic surgery, a chest tube is usually placed for closed drainage to expel gas accumulation in the thoracic cavity and fluid accumulation to promote lung re-expansion. It can also be observed whether there is active bleeding after the operation and whether there is a pulmonary leak. The conventional drainage of the chest cavity is connected with a water-sealed drainage bottle, and the patient condition is judged by observing the drainage situation and the fluctuation of the water column, which is a very classic method. However, the water-sealed bottle has the disadvantages of being easy to overturn and inconvenient to carry, which is not conducive to the early activities of patients. Under the concept of accelerated rehabilitation, our center applied a new type of anhydrous thorax negative pressure drainage device and achieved good results. The purpose of this study was to observe the effect of a new type of anhydrous thoracic negative pressure drainage device in patients after thoracic surgery.@*METHODS@#Retrospective analysis of patients who underwent lung surgery in the First Affiliated Hospital of Zhejiang University Medical College from January 2018 to December 2019, patients were divided into two groups. One group of patients used a traditional closed-chest drainage water-sealed bottle as a control group, and the other group used a new type of anhydrous negative-pressure drainage bottle as an experimental group. Patients' gender, age, hypertension, diabetes, smoking history, surgical incisions and surgical methods, and the length of hospital stay and postoperative hospital stay were calculated.@*RESULTS@#There were no statistical differences in age, gender, comorbidities (hypertension, diabetes, smoking history), scope of surgery, and duration of surgery between the two groups of patients, but there were statistical differences in surgical incisions between the two groups of patients (P=0.01). We found that patients using the new waterless negative pressure drainage device were shorter than patients with water negative pressure drainage device in terms of postoperative hospital stay and total hospitalization time, and the difference was statistically significant (P=0.02, P=0.04).@*CONCLUSIONS@#The new type of anhydrous thoracic negative pressure drainage device has a good effect on the rapid recovery and advancement after thoracic surgery.
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BACKGROUND@#Thoracoscopic safe and effective hemostasis is an important condition for rapid rehabilitation of thoracic surgery. Placing hemostatic materials during surgery is a commonly used method in lung cancer laparoscopic surgery. Among them, resorbable oxidized cellulose is a commonly used hemostatic material. This research aims to observe the hemostatic effect of resorbable oxidized cellulose in lung cancer surgery.@*METHODS@#A retrospective analysis of 42 patients with thoracoscopic lung cancer undergoing radical surgery in the Department of Thoracic Surgery, First Affiliated Hospital of Zhejiang University School of Medicine from July 1, 2018 to December 1, 2018, and intraoperative use of regenerative oxidized cellulose to stop bleeding The clinical and pathological data were selected and the perioperative indicators were selected as the outcome events for statistical analysis.@*RESULTS@#The mean operative time was (120.5±57.3) min. The mean intraoperative blood loss was (26.8±21.6) mL. The average postoperative drainage volume was (513.6±359.5) mL. The average postoperative chest tube indwelling time was (2.6±1.2) d.@*CONCLUSIONS@#The use of absorbable regenerated oxidized cellulose in the radical operation of thoracoscopic lung cancer has a good hemostasis effect, and is suitable for hemostasis of wounds after lymph node dissection.
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BACKGROUND@#To investigate the diagnostic significance of percutaneous lung puncture for solid pulmonary nodules (diameter ≤15 mm).@*METHODS@#This study retrospectively included 20 patients with solid pulmonary nodules who underwent percutaneous puncture from January 2014 to December 2018, including 11 males and 9 females. The diameter of the lesion is between 0.5 cm-1.5 cm, excluding severe organ dysfunction, and patients with coagulopathy.@*RESULTS@#All 20 patients were successfully selected, and 19 patients were diagnosed with pathological diagnosis. Among them, 11 patients found malignant tumor cells, which were clearly malignant tumors of the lungs, 5 cases of chronic inflammation of the lungs, 2 cases of fibrous tissue hyperplasia, and 1 case of lung cartilage tissue, no tumor cells were found in 1 case. One patient with a small amount of pneumothorax after puncture and one patient with a small amount of pleural effusion on the puncturesite.@*CONCLUSIONS@#Percutaneous lung puncture has a high effectiveness and safety for the diagnosis of solid pulmonary nodules.
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Objective To investigate the possible mechanism of endonuclease G (Endo G)-mediated non-Caspase-dependent apoptotic pathway in brain neuronal apoptosis in chronic fluorosis rats.Methods Sixty Sprague Dawley (SD) rats (half male and half female) were randomly divided into two groups:control group fed with tap water with fluoride content ＜ 0.5 mg/L and fluorine group in which sodium fluoride was added into drinking water with fluoride content of 50.0 mg/L.Both groups were fed with standard food with fluorine content ＜ 0.5 mg/kg.The experiment period was 10 months.At the end of the experiment,all the animals were sacrificed,and brain tissue was taken.Flow cytometry was used to examine apoptosis rate,immune-histochemistry was employed to detect the distribution of Endo G in brain tissue;Western blotting was used to test the protein expression of Endo G.Results Compared to the apoptosis rate of control group [(1.3 ± 0.6)％,(1.9 ± 0.3)％],the apoptosis rate in hippocampus and cortex of rats with chronic fluorosis [(2.6 ± 0.6)％,(3.1-± 0.7)％] was significantly increased (t =3.1,3.4,all P ＜ 0.05).The Endo G positive neurons and their degree of staining in CA1,CA2,CA3 and CA4 of hippocampus,frontal cortex as well as the upper layer of parietal cortex [(11.1 ± 2.2),(10.2 ± 1.9),(9.8 ± 3.1),(9.9 ± 1.6),(10.6 ± 2.9),(8.2 ± 2.4),(11.1 ± 2.8) scores] in rats with chronic fluorosis were significantly higher than those in the control group [(5.8 ± 1.8),(6.7 ± 2.6),(5.2 ± 2.4),(7.2 ± 2.1),(7.7 ± 2.6),(6.1 ± 1.9),(8.1 ± 2.6) scores,t =2.9,2.5,2.4,2.3,2.2,2.5,2.3,P ＜ 0.01 or ＜ 0.05].The protein level of Endo G in the mitochondria of rat brains with chronic fluorosis [(86.4 ± 7.2)％,(83.9 ± 6.8)％] was significantly lower than that of control group [(100.0 ± 6.1)％,(100.0 ± 5.5)％,t =2.6,2.3,all P ＜ 0.05].Meanwhile,the protein level of Endo G in the nucleus of neurons from chronic fluorosis rats [(117.5 ± 6.4)％,(115.2 ± 6.2)％] was significantly higher than that of the control [(100.0 ± 5.2)％,(100.0 ± 5.5)％,t =2.5,2.2,all P ＜ 0.05].Conclusion The high expression of Endo G and nuclear transfer are related to the neuron apoptosis in chronic fluorosis rat,which may be one of the mechanisms of brain injury of the disease.
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Objective To investigate the association between HLA-DP gene polymorphism and the susceptibility to hepatitis B virus (HBV) infection in people in Buyi,Miao and Shui ethnic groups in Guizhou.Methods A total of 256 patients with HBV infection,142 HBV self-cleared patients and 135 controls were recruited from 3 ethnic groups for this case-control study.Genotypes of rs3077 and rs9277535 were determined by using real-time PCR with a TaqMan-MGB probe.Results Compared with healthy subjects and self-cleared subjects,the allele distribution of rs9277535 was significantly associated with chronic HBV infection (P＜0.05),no significant differences in rs3077 allele and genotype distributions were found among 3 groups (P＞0.05).Compared with the rs9277535 GG genotype,the AA and AG genotypes were protective factors against HBV infection in dominant model after adjustment for age and sex (OR=0.645,95％CI:0.421-0.988),and no significant difference in rs3077 locus was found in the same analysis (P＞0.05).For men,the rs3077 locus CC and CT genotypes were also protective factors against HBV infection (OR=0.493,95％CI:0.266-0.916),and there was no significant difference in rs9277535 locus compared the genotype distributions among 3 groups in dominant mode.Comparison of allele and genotype distribution in 3 ethnic groups showed that HLA-DP gene rs3077 genotype distributions had significant difference between the HBV infection group and the healthy control group in Buyi ethnic group (x2=6.726,P=0.036).Conclusions The presence of rs9277535A allele at HLA-DP gene polymorphisms might decrease the risk for HBV infection,the rs3077 C allele at HLA-DP gene polymorphisms might also confer protective effect against HBV infection in women.No significant correlation between HLA-DP gene rs3077 and rs9277535 locus polymorphism and HBV clearance was found in this study.The HLA-DP gene rs3077 genotype distribution of HBV-infected patients had significant differences among different ethnic groups.
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Objective To investigate the possible pathological role of mitochondrial apoptosis pathways and its factors in fluorosis-induced apoptosis of human hepatocellular carcinoma cell strain (HepG2).Methods Under the stimulation of 1,3,6 and 9 mmol/L concentrations of NaF in vitro for 24 h (n =5),while normal control group was cultured under normal condition,the cytotoxicity was measured with MTT.The mitochondrial apoptosis inducing factor (AIF) was measured at both mRNA (n =5) and protein levels (n =6),respectively,by real-time PCR and Western blotting.The mitochondrial apoptosis related factors,such as B-cells lymphoma-2 (Bcl-2),Bcl-associated X protein (Bax),cytochrome C,caspase-9 and caspase-3 were measured at protein levels (n =6).Results After treated with 0,1,3,6 and 9 mmol/L NaF for 24 h,the cell absorbance of HepG2 cells was 0.307 ± 0.031,0.333 ± 0.028,0.230 ± 0.011,0.178 ± 0.001 and 0.152 ± 0.003,respectively,and the differences were statistically significant among groups (F =82.224,P ＜ 0.01).After treated with 3 mol/L NaF for 24 h,the mRNA level of AIF was [(153.14 ± 5.41)％] which was increased compared to the control group [(100.00 ± 4.70)％,t =-4.73,P ＜0.05].Under the same condition,the protein levels of AIF,Bcl-2,cytochrome C in cytoplasm,caspase-9 and caspase-3 were (152.16 ± 47.30)％,(171.90 ± 51.52)％,(458.00 ± 19.48)％,(527.17 ± 200.67)％ and (432.70 ±64.27)％,which were increased compared to those of the control groups [(100.00 ± 48.86)％,(100.00 ± 34.44)％,(100.00 ± 116.59)％,(100.00 ± 19.58)％ and (100.00 ± 137.16)％,t =-3.80,-3.96,-15.76,-4.64,-5.06,all P ＜ 0.05],while the protein levels of Bax and cytochrome C in mitochondrion were (24.66 ± 26.04)％,(72.99 ±45.34)％,which were decreased compared to those of the control groups [(100.00 ± 44.01)％,(100.00 ± 34.14)％,t =6.35,0.68,all P ＜ 0.05].Conclusion The mitochondrial apoptosis pathway and related factors may be involved in NaF-induced cell death in HepG2 cells.
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Objective To understand the ABO blood type distribution of Buyi and Shui ethnic populations in Libo county of Guizhou province .Methods Totally 726 Buyi and 163 Shui individuals who were unrelated within three generations were detected ABO blood stype with glass-clotted method .Results The ABO blood type distributions in the Buyi and Shui ethnic populations both were in line with the Hardy-Weinberg equilibrium .The Buyi ethnic population ABO phenotypic distribution and gene frequen-cies were O>B>A>AB and r>q>p (r=0 .676 9 ,q=0 .176 7 ,P=0 .146 4) and the national index was 0 .842;while the Shui eth-nic population ABO phenotypic distribution and gene frequencies were O>A>B>AB and r>p>q(r=0 .522 6 ,q=0 .104 0 ,P=0 .164 7) and the national index was 1 .529 .Conclusion The Buyi and Shui ethnic populations′ABO blood type distribution in Libo county of Guizhou province is basically consistent with that of the same ethnic populations in other regions of Guizhou Province of the same ethnic groups .The genetic distance analysis prompts that the regional and ethnic differences exist in ABO blood type dis-tribution .
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Objective To investigate the pathological role of endoplasmic reticulum stress in fluomsisinduced apoptosis in human hepatocellular carcinoma cell line (HepG2).Methods Under stimulation of 1,3,6,9 mmol/L concentrations of NaF in vitro for 24 h,while normal control group was cultured under normal condition,the apoptosis of HepG2 cells was measured by flow cytometry.The endoplasmic reticulum stress markers (glucose regulative proteins 78,94;GRP78,GRP94) and CCAAT/enhancer-binding protein homologous protein (CHOP) in HepG2 cells were measured at both mRNA and protein levels by real-time PCR and Western blotting,respectively.Results After treated with 0,1,3,6,9 mmol/L NaF for 24 h,the apoptosis rate of HepG2 cells was (6.25 ± 1.27)％,(13.48 ± 1.00)％,(24.08 ± 1.88)％,(30.19 ± 3.07)％ and (37.72 ± 4.43)％,respectively,and the difference was statistically significant among groups (F =65.828,P ＜ 0.01).After treated with 3 mmol/L NaF for 24 h,the mRNA level of GRP78,GRP94 and CHOP was (1 172.41 ± 459.60)％,(946.95 ± 635.85)％ and (7 846.97 ± 1 670.01)％,which was increased compared to those of the control groups [(100.00 ± 1.77)％,(100.00 ± 2.08)％,(100.00 ± 0.74)％,t =12.77,4.67,11.50,all P ＜ 0.01].Under the same condition,the protein levels of GRP78 and CHOP were (159.99 ± 67.59)％ and (155.15 ± 94.24)％,which were increased compared to those of the control groups [(100.00 ± 30.68)％,(100.00 ± 41.44)％,t =-3.27,-1.99,all P ＜ 0.05],while GRP94 protein level [(46.40 ± 41.46)％] was decreased compared to that of the control group [(100.00 ± 68.86)％,t =4.02,P ＜ 0.05].Conclusion Endoplasmic reticulum stress may be involved in NaF-induced cell death in HepG2 cells.
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Objective To investigate fluoride-induced inflammation and nuclear factor-κB (NF-κB) signaling pathway in cultured human acute monocytic leukemia cells (THP-1).Methods In vitro cultured THP-1 cells were used as a model of microglia.After cultured with different concentrations of [0 (negative control group),10,50,100,500,1 000 and 5 000 μmol/L] sodium fluoride (NaF) for 48 h,the survival of cells was detected by CCK8.THP-1 cells were divided into 3 groups:control group,low dose and high dose fluoride groups according to the results of CCK8 assay,and then treated with different concentrations of sodium fluoride (0,500,5 000 μmol/L) for 48 h,concentrations of inflammatory cytokines,such as Interleukin-lβ (IL-1β) and tumor necrosis factor-α (TNF-α) were measured by enzyme linked immunosorbent assay (ELISA) in THP-1 mononuclear cell culture medium.The protein levels of IκBα,phospho-NF-κB p65 and phospho-IκB-α were detected by Western blotting.Results THP-1 cells were treated with different concentrations of sodium fluoride (500,1 000,5 000 μ mol/L) for 48 h.Fluoride group THP-1 cell survival rate [(73.21 ± 3.67)％,(31.40 ± 4.56)％,(0.40 ± 0.24)％] was lower than that of the negative control group [(100.00 ± 0.00)％,all P ＜ 0.01].Compared to the control groups [(0.36 ± 0.07),(31.07 ± 0.81)ng/L],significant increases of the inflammatory cytokines IL-1β [(1.42 ± 0.79),(19.47 ± 2.90)ng/L] and TNF-α [(61.06 ± 2.20),(172.72 ± 2.29)ng/L] were detected in culture medium in low-fluoride and high fluoride groups,respectively.Interestingly,compared to the control groups [(100.00 ± 5.48)％,(100.00 ± 14.82)％],significant increases of phospho-NF-κB p65 [(113.71 ± 8.99)％,(134.74 ± 1.93)％] and phospho-IκB-α [(152.61 ± 14.16)％,(176.91 ± 7.95)％] were observed in both low-fluoride and high fluoride groups.Meanwhile,the protein level of IκBα in high fluoride group [(63.53 ± 9.67)％] was significantly lower than that of the control group [(100.00 ± 10.99)％,P ＜ 0.01].Furthermore,significant positive correlation was detected between increased IL-1β,TNF-α and phospho-NF-κB p65 (r =0.74,0.72,all P ＜ 0.05).Conclusions Excessive fluoride can induce microglial cells to release inflammatory cytokines and activate nuclear factor-κB signaling pathway.The release of inflammatory cytokines and activation of the signaling pathway may be one of the mechanisms of the damage of the central nervous system caused by sodium fluoride.
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Objective To explore the role of apoptosis-inducing factors (AIF) mediated non-apoptosis classic pathway involved in neuron apoptosis of rats with chronic fluorosis.Methods Sixty Sprague Dawley (SD) rats (body weight 100-120 g) were divided into two groups (30 rats in each group,half male and half female) by random number table according to body weight.Control group was fed with tap water with fluoride content ＜ 0.5 mg/L and fluorine group was fed with water with fluoride content of 50.0 mg/L.Both groups were fed with standard food with fluorine content ＜ 0.5 mg/kg.After 10 months,all the animals were sacrificed though heart perfusion using phosphate buffer,and brain tissue was taken.Immunohistochemical method was employed to detect the distribution of AIF in brain tissue.Western blotting was used to test the protein expression of AIF,cl-caspase-3 and cl-caspase-9.Flow cytometry was used to examine apoptosis rate.Results The AIF positive distribution and degree of staining in the neurons of hippocampal CA1,CA2 and CA3,as well as the parietal cortex (7.50 ± 2.17,9.00 ± 1.63,8.00 ±0.82,10.24 ± 1.80) in rats with chronic fluorosis were significantly higher than those of the control group (5.18 ±1.66,6.27 ± 1.42,6.36 ± 1.96,6.96 ± 2.62,t =2.76,4.09,2.45,5.77,all P ＜ 0.05).The AIF protein expression of neuronal mitochondria in the cerebral tissue of rats with chronic fluorosis [(89.46 ± 8.47)％] was significantly lower than that of the control group [(100.00 ± 7.12)％,t =3.16,P ＜ 0.01],while the AIF protein expression of the neuronal nucleus [(112.80 ± 7.10)％] was significantly higher than that of the control group [(100.00 ± 8.20)％,t =3.75,P ＜ 0.01];cl-caspase-3 and cl-caspase-9 protein expression in the neurons of hippocampus and cortex from the rats with chronic fluorosis [(132.14 ± 18.66)％,(107.31 ± 2.58)％,(121.33 ± 14.86)％,(112.97 ± 7.97)％]were significantly higher than those of the control group [(100.00 ± 11.99)％,(100.00 ± 3.74)％,(100.00 ± 16.87)％,(100.00 ± 8.04)％,t =3.55,3.94,2.32,2.81,P ＜ 0.01 or ＜ 0.05].As compared with those of the control group [(1.28 ± 0.59)％,(1.88 ± 0.25)％],the apoptosis rates in hippocampus and cortex of the rats with chronic fluorosis [(2.55 ± 0.58)％,(3.05 ± 0.65)％] were significantly increased (t =3.08,3.40,all P ＜ 0.05).Conclusion Both of AIF-mediated caspase-independent apoptosis and the classic caspase-dependent apoptosis pathways have participated in neuron apoptosis in rat induced by chronic fluorosis,which may be one of the mechanisms of brain damage of the disease.