Aim To observe the effect of BAPTA-AM on extracellular acid-induced autophagy in rat articular chondrocytes and its possible mechanisms.Methods Rat articular chondrocytes were isolated from Sprague-Dawley rats and incubated with different pH medium. The states of autophagy were examined by acridine or-ange (AO ) staining .Moreover,the expressions of LC3 ,Beclin-1 ,ULK1 ,CaMKKβ,AMPK and mTOR were detected using Western blot or quantitative real-time PCR (qRT-PCR ). Intracellular calcium ([Ca2+]i )was analyzed by a Ca2+-imaging method. Results Compared with pH 6.0 group,BAPTA-AM could significantly decrease the activation of autophagyinduced by acid exposure,and the expressions of autophagy markers including LC3 Ⅱ,Beclin1 and ULK1were also decreased,accompanied with reduced acidinduced [Ca2 +]i influx,decreased proteins expressionof CaMKKβand phosphorylatedAMPK,and increasedphosphorylation of mTOR.Conclusion BAPTAAMcan significantly restrain acidinduced autophagy in ratarticular chondrocytes,the mechanism of which may beassociated with decreased Ca2 + influx.

Aim To study the effects of extracellular acidosis on articular chondrocytes pyroptosis and its possible mechanisms. Methods Primary articular chondrocytes were incubated in different pH and NAC. The expression of proinflammatory cytokines IL-1β, IL-18, ASC, NLRP3, caspase-1 were detected by Western blot and real-time PCR. The state of pyropto-sis was identified by AO/EB staining and LDH con-tents. The expression of ROS was observed by DCFH-DA, and ELISA was used to detect the IL-1β,IL-18 in cultured supernatants. Results Compared with the normal cell, extracellular acidosis could increase the expression of IL-1β, IL-18, ASC, NLRP3 and caspase-1 , upregulate the fluorescence intensity of in-tercellular ROS, accompanied with the promoted release of LDH. Moreover, it is observed that extra-cellular acidosis could also induce chondrocytes death by AO/EB staining. NAC,the scavenger of ROS could inhibit these effects of extracellular acidosis on chon-drocytes. Conclusion Extracellular acidosis may in-duce chondrocyte pyroptosis via upregulating the intra-cellular ROS content.

Objective To summarize the pathology of congenital intestinal atresia,the incidence and prenatal diagnosis rate of different types,and to analyze the location and type of intestinal atresia as well as the factors that affect the mortality of various types of intestinal atresia.Method We retrospectively analyzed the clinical data of 147 children with congenital intestinal atresia from January 2013 to March 2016,including gender,gestational age,parity,prenatal diagnosis or not,delivery methods,hospital admission,surgical methods,findings during surgery,combined malformations,complications and prognosis.They were analyzed statistically.Result A total of 147 cases,including 69 males and 78 females were enrolled.There were 40 premature infants and 107 full term cases.Twins were found in 3 cases.Hospital admission age range from 1 hour to 62 days;admission weight range from 1 480 g to 4 200 g;32 cases were diagnosed before birth.2 cases were abandoned before surgery because of trisomy 21.Postoperatively,the occlusion sites was confirmed as following:67 cases (46.2％) in ileum,43 cases (29.7％) in jejunum,26 cases (17.9％) in duodenum,and 9 cases (6.2％) in colon.The pathological types were as following:type Ⅰ 42 cases (29.0％),type Ⅱ 8 cases (5.5％),type Ⅲa 65 cases (44.8％),type Ⅲb 15 cases (10.3％) and type Ⅳ 15 cases (10.3％).22 cases (14.9％) were died because of refusal of treatment:7 cases were due to short bowel syndrome and meconium peritonitis,6 cases were due to postoperative chronic pseudo-obstruction,and 5 cases had anastomotic leakage requiring reoperation.1 case had postoperative enterocolitis and gave up treatment,1 case had anastomotic leak and sever systemic post-surgery infection and gave up further treatment,and 2 cases gave up because of 21-trisomy syndrome.Conclusion The operation plan of intestinal atresia should be based on the location and type of the blockade;the location and complications of the blockade (pseudo-obstruction,short bowel syndrome,and anastomotic leakage) are important factors affecting the treatment and prognosis.

Objective To investigate the effect of surgical treatment of necrotizing enterocolitis (NEC) with different surgical ages.Methods From January 2014 to December 2017,105 neonates with NEC in our hospital were divided into early operation group (operation age ＜ 7 days,n =47) and late operation group (7 ＜ operation age ＜ 28 days,n =58).The general data,surgical indications,intraoperative conditions,surgical methods,postoperative complications,and postoperative survival rates were compared between the two groups.Results Among the 105 neonates with NEC,74 were male and 31 were female.The average birth weight was (2 398 ± 927)g,and the average gestational age was (35 ± 4)weeks.Compared with the early operation group,the late operation group had lighter birth weight,smaller gestational age and higher rate of respiratory failure (P ＜ 0.05).There was no significant difference between the two groups in the proportion of surgical indications (diffuse peritonitis,pneumoperitoneum,and medical treatment ineffective) (P ＞ 0.05).The necrosis rate of small intestine in the late operation group was higher than that in the early operation group,but the necrosis rate of small intestine and colon was lower than that in the early operation group (P ＜ 0.05).There was no significant difference in the proportions of the two groups in the surgical methods (enterostomy,intestinal resection and anastomosis and enterostom,exploratory laparotomy,abdominal drainage,and intestinal resection and anastomosis) (P ＞ 0.05).The incidence of intestinal stenosis in early operation group was higher than that in late operation group (P ＜ 0.05).The survival rate of early operation group was 78.7％,while that of late operation group was 63.8％,with no significant difference (P ＞ 0.05).Conclusions The patients with NEC who were operated within 1 week after birth are more common in term infants and with colon necrosis,and are more likely to occur intestinal stenosis after surgery.The patients with NEC who were operated after 1 week of birth are more common in prematures and low-birth-weight patients,and are often associated with respiratory failure.Pneumoperitoneum and diffuse peritonitis are common surgical indications for NEC.Enterostomy is the major surgical method.Choosing the right timing and surgical method can improve the prognosis of patients with NEC.

Objective To investigate the role and possible mechanism of curcumin(Cur)regulating Peroxiredoxin-6(Prdx6)expression in inhibiting Erastin-induced ferroptosis in C28/I2 chondrocytes.Methods Safranin O/Fast Green and hematoxylin-eosin(HE)staining were performed to observe the pathological changes in the knee joint of rats with osteoarthritis(OA).The expression levels of Prdx6 and GPX4 proteins in cartilage tissues with OA were detected by immunohistochemistry and Western blot.C28/I2 chondrocytes were treated with different concentrations of Cur,cell viability was detected by thiazolyl blue tetrazolium bromide(MTT)assay and cytotoxicity was measured by lactic dehydrogenase(LDH)assay.The production of lipid reactive oxygen species(ROS)in chondrocytes was detected by flow cytometry,and the total glutathione(GSH)assay kit was used to detect the GSH level in chondro-cytes.Western blot was performed to detect the expression level of Prdx6 and ferroptosis-related proteins in chon-drocytes.The interaction between the Cur molecule and Prdx6 was analyzed through the molecular docking tech-nique.Results During the OA progression,OA rats and OA patients showed pathological changes such as damage to the cartilage and a decrease in the number of chondrocytes.The expression levels of Prdx6 and GPX4 were re-duced in the cartilage tissues of OA patients compared with healthy people.Further study revealed that the treat-ment of Erastin-induced ferroptosis in C28/I2 chondrocytes in a mouse model with 20 μmol/L of Cur could improve cell viability,decrease cytotoxicity,inhibit lipid ROS production,and increase the level of intracellular GSH.Western blot results showed decreased expression of Prdx6,SLC7A11,FTH,and GPX4 and increased expression of ACSL4.In addition,Cur molecules interacted with Prdx6 protein by van der Waals forces and π bond.Conclu-sion Cur may inhibit Erastin-induced ferroptosis in C28/I2 chondrocytes by upregulating the Prdx6 expression lev-el.

Objective To investigate the role of Taraxasterol(TAR)on ferroptosis in chondrocytes induced by Erastin.Methods The C28/I2 chondrocyte line was treated with Erastin to construct the ferroptosis model of chon-drocytes in vitro and the experiments were divided into Control,Erastin,TAR,and TAR+Erastin groups.Cell via-bility was detected by the CCK-8 assay.Cytotoxicity was detected by the lactate dehydrogenase(LDH)kit and the Calcein/PI cytokinesis kit.Flow cytometry was used to detect lipid reactive oxygen species(ROS).The intracellular glutathione(GSH)content was detected by GSH kit.Mitochondrial membrane potential was detected by JC-1 stai-ning and RH123 staining.ACSL4 and GPX4 protein expression and the key indicators of ferroptosis were detected by Western blot.Results TAR restored the decreased cell viability of C28/I2 chondrocytes induced by Erastin treatment as well as reduced Erastin-induced cytotoxicity(P＜0.01).Compared with the control group,the level of intracellular lipid ROS increased(P＜0.01)and the content of GSH decreased(P＜0.01)after treatment with Erastin,while TAR could reduce the production of lipid ROS(P＜0.01)and increase the content of GSH(P＜0.01).TAR restored mitochondrial membrane potential in C28/I2 chondrocytes ferroptosis,decreased ACSL4 pro-tein expression(P＜0.01)and increased GPX4 protein expression(P＜0.01).In addition,TAR restored the re-duced cell viability caused by IL-1 β treatment.Conclusion TAR can inhibit Erastin induced ferroptosis in C28/I2 chondrocytes,which may be related to the regulation of ACSL4 and GPX4 protein expression.

Objective: To investigate the effect of acid-sensing ion channel 1 (ASIC1) gene knockout on articular cartilage injury in adjuvant arthritis (AA) of mice． Methods: Wild-type mice and ASIC1 knockout mice were divided into normal group and model group．Arthritis score was performed by observing the inflammation of paws，and the right paw swelling was measured．HE staining，immunohistochemistry，TUNEL and ELISA were used to detect the injury of articular cartilage and arthritic inflammation. Results : The arthritis score and paw swelling of AA mice with ASIC1 knockout was lower than that of the AA wild-type mice．AA mice with ASIC1 knockout showed less destruction and increased expression of collagen-Ⅱin articular cartilage． Moreover ，the lower apoptosis rate was observed by TUNEL assay in AA mice with ASIC1 knockout by comparing with AA wild-type mice．Furthermore，ELISA assay showed that the levels of IL-1 β、TNF-α in the serum decreased in AA mice with ASIC1 knock- out． Conclusion Knockout of ASIC1 may have protective effect on articular cartilage injury.

Stroke is a brain injury caused by sudden rupture or blockage of blood vessels in the brain, with different types and varying degrees death in cellular level. And there is currently no effective treatment for it. Ferroptosis is a new type of cell death discovered in recent years that is related to factors such as lipid peroxides, reactive oxygen species (ROS), and Fe

Objective To explore the effect of 2-aminoethoxy-diphenyl borate(2-APB)on H2O2-induced chondro-cyte apoptosis and its mechanism.Methods The experiment was divided into control group,H2O2 group,2-APB group and H2O2+2-APB group.CCK-8 method was used to detect the cell viability of each group;The effect of 2-APB on the morphological changes of chondrocytes induced by H2O2 was observed under microscopy;TUNEL meth-od and flow cytometry were used to detect chondrocyte apoptosis;Flow cytometry was used to detect Lipid reactive oxygen species(ROS);Western blot was used to detect the protein expressions of Cleaved-PARP,p-PKCα and HIF-1α in H2O2-induced cells by 2-APB;Immunofluorescence was used to detect the fluorescent expression of HIF-1α in cells induced by H2O2 by PKCα inhibitor BIM-1.Results 2-APB inhibited H2O2-induced apoptosis in chon-drocytes,and the inhibitory effect was the most significant when the concentration of 2-APB was 100 pmol/L(F=235.80,P＜0.01);22-APB could inhibit the positive rate of H2O2-induced apoptosis of chondrocytes(F=114.80,P＜0.01)and the level of ROS(F=52.99,P＜0.01).and inhibited the expression of Cleaved-PARP(F=10.10,P＜0.05),p-PKCα(F=24.56,P＜0.05)and HIF-1α proteins(F=6.85,P＜0.05).The PKCα in-hibitor BIM-Ⅰ could inhibit the increase in HIF-1α fluorescence intensity caused by H2O2.Conclusion 2-APB can inhibit chondrocytes apoptosis induced by H2O2 through the PKCα/HIF-1α pathway and thus protect chondro-cytes.

AIM:To investigate the effect of Cara-gana sinica root(CSR)on ferroptosis in the Erastin-induced chondrocyte ferroptosis model and possi-ble mechanisms.METHODS:The C28/I2 chondro-cyte cell line was cultured to construct a cell model of Erastin-induced ferroptosis.Cell viability was de-tected by MTT assay;cell death was observed by Calcein/PI staining;cell lactate dehydrogenase(LDH)and total glutathione(GSH)levels were de-tected by the kit;reactive oxygen species(ROS)lev-els were detected by fluorescent probe BODIPY 581/591 C11 labeling;mitochondrial membrane po-tential(ΔΨm)changes were observed by Rh123 and JC-1 staining;Western blot was used to detect the expression of ferroptosis-related proteins(AC-SL4,GPX4)and TRPM7 proteins.RESULTS:Erastin treatment decreased chondrocyte viability,in-creased cytotoxicity,induced oxidative stress,dis-rupted ΔΨm,and up-regulated ACSL4 protein ex-pression,while down-regulating GPX4 protein ex-pression and inducing chondrocyte ferroptosis.In contrast,CSR restored cell viability and reduced oxi-dative stress,thereby inhibiting chondrocyte fer-roptosis.In addition,CSR reduced the Erastin-in-duced increase in TRPM7 protein expression level.CONCLUSION:Erastin induced lipid peroxidation in C28/I2 chondrocytes,causing mitochondrial dam-age and ferroptosis;CSR may inhibit chondrocyte ferroptosis by blocking TRPM7,thus exerting a pro-tective effect on chondrocytes.