ObjectiveTo explore the role of cucurbitacin B （CuB） in inducing ferroptosis in 4T1 cells and its mechanism. MethodsThe effects of CuB（0.2， 0.4， 0.8 μmol·L^-1）on the proliferation ability of 4T1 cells in vitro were detected using the methyl thiazolyl tetrazolium （MTT） assay. The clonogenic ability of 4T1 cells was detected by the plate cloning assay， and the levels of lactate dehydrogenase （LDH） in 4T1 cells were detected by the use of a kit. The mitochondrial membrane potential and reactive oxygen species （ROS） levels in 4T1 cells were detected by flow cytometry， and the mitochondrial ultrastructure of 4T1 cells was observed by transmission electron microscopy. The western blot was used to detect the expression of ferroptosis-related protein p53 in 4T1 cells， solute carrier family 7 member 11 （SCL7A11）， glutathione peroxidase 4 （GPX4）， long-chain acyl-CoA synthetase 4 （ACSL4）， transferrin receptor protein 1 （TFR1）， and ferritin heavy chain 1 （FTH1）. ResultsCompared with that in the blank group， the survival rate of 4T1 cells in CuB groups was significantly decreased （P<0.05）， and the number of cell clones in CuB groups was significantly reduced （P<0.01）. In addition， compared with that in the blank group， the leakage of LDH in cells in CuB groups was significantly increased （P<0.01）， and the mitochondrial membrane potential of cells in CuB groups decreased significantly （P<0.01）. Cellular ROS levels were significantly elevated in CuB groups （P<0.01）. The mitochondria of cells in CuB groups were obviously wrinkled， and the mitochondrial cristae were reduced or even disappeared. Compared with that in the blank group， the protein expression of p53， ACSL4， and TFR1 were significantly up-regulated in CuB groups （P<0.05）， and that of SLC7A11， GPX4， and FTH1 were significantly down-regulated （P<0.05）. ConclusionCuB may inhibit SLC7A11 and GPX4 expression by up-regulating the expression of p53， which in turn regulates the p53/SLC7A11/GPX4 signaling pathway axis and accelerates the generation of lipid peroxidation substrate by up-regulating the expression of ACSL4. It up-regulates TFR1 expression to promote cellular uptake of Fe³⁺ and down-regulates the expression of FTH1 to reduce the ability of iron storage， resulting in an elevated free Fe²⁺ level. It catalyzes the Fenton reaction， generates excess ROS， imbalances the antioxidant system and iron metabolism， and then induces ferroptosis in 4T1 cells.

ObjectiveTo explore the role of cucurbitacin B （CuB） in inducing ferroptosis in 4T1 cells and its mechanism. MethodsThe effects of CuB（0.2， 0.4， 0.8 μmol·L^-1）on the proliferation ability of 4T1 cells in vitro were detected using the methyl thiazolyl tetrazolium （MTT） assay. The clonogenic ability of 4T1 cells was detected by the plate cloning assay， and the levels of lactate dehydrogenase （LDH） in 4T1 cells were detected by the use of a kit. The mitochondrial membrane potential and reactive oxygen species （ROS） levels in 4T1 cells were detected by flow cytometry， and the mitochondrial ultrastructure of 4T1 cells was observed by transmission electron microscopy. The western blot was used to detect the expression of ferroptosis-related protein p53 in 4T1 cells， solute carrier family 7 member 11 （SCL7A11）， glutathione peroxidase 4 （GPX4）， long-chain acyl-CoA synthetase 4 （ACSL4）， transferrin receptor protein 1 （TFR1）， and ferritin heavy chain 1 （FTH1）. ResultsCompared with that in the blank group， the survival rate of 4T1 cells in CuB groups was significantly decreased （P<0.05）， and the number of cell clones in CuB groups was significantly reduced （P<0.01）. In addition， compared with that in the blank group， the leakage of LDH in cells in CuB groups was significantly increased （P<0.01）， and the mitochondrial membrane potential of cells in CuB groups decreased significantly （P<0.01）. Cellular ROS levels were significantly elevated in CuB groups （P<0.01）. The mitochondria of cells in CuB groups were obviously wrinkled， and the mitochondrial cristae were reduced or even disappeared. Compared with that in the blank group， the protein expression of p53， ACSL4， and TFR1 were significantly up-regulated in CuB groups （P<0.05）， and that of SLC7A11， GPX4， and FTH1 were significantly down-regulated （P<0.05）. ConclusionCuB may inhibit SLC7A11 and GPX4 expression by up-regulating the expression of p53， which in turn regulates the p53/SLC7A11/GPX4 signaling pathway axis and accelerates the generation of lipid peroxidation substrate by up-regulating the expression of ACSL4. It up-regulates TFR1 expression to promote cellular uptake of Fe³⁺ and down-regulates the expression of FTH1 to reduce the ability of iron storage， resulting in an elevated free Fe²⁺ level. It catalyzes the Fenton reaction， generates excess ROS， imbalances the antioxidant system and iron metabolism， and then induces ferroptosis in 4T1 cells.

Ferroptosis， a new form of programmed cell death different from apoptosis， necrosis， and autophagy， is closely associated with a variety of physiological and pathological processes. Iron-mediated accumulation of reactive oxygen species is the main inducement of ferroptosis， the mechanism of which is related to intracellular lipid metabolism， iron metabolism， and antioxidant defense pathways. Multiple signaling axes and regulators jointly regulate the occurrence and disruption of ferroptosis. Studies have demonstrated that ferroptosis regulates the growth and proliferation of tumor cells. Inducing ferroptosis in tumor cells can control the growth， metastasis， and multi-drug resistance of tumors. Therefore， the effect and mechanism of ferroptosis on tumor cells have become a hot topic in anti-cancer research. As the research advances， a variety of ferroptosis inducers has been used in the clinical chemotherapy for cancers and demonstrate significant efficacy. Accordingly， the development of ferroptosis-inducing anticancer drugs has become a new research direction for tumor treatment. Some active ingredients such as lycorine， oleanolic acid， dihydroartemisinin， pseudolaric acid B， and ophiopogonin B of Chinese medicines can induce ferroptosis in tumor cells via lipid metabolism， iron metabolism， system X_c^-， and GPX4/GSH to regulate the development of tumors， demonstrating a promising prospect in clinical treatment. Based on the theory of the mechanism of ferroptosis， this paper reviews the research progress in ferroptosis induced by active ingredients of Chinese medicines in tumor cells and describes the metabolic regulatory network of ferroptosis from signaling pathways and regulatory factors， providing new strategies for applying active ingredients of Chinese medicines in the treatment of tumors.

ObjectiveTo investigate the induction of ferroptosis by polyphyllin Ⅱ （PPⅡ） in hepatocellular carcinoma HepG2 cells and its underlying mechanism. MethodThe effect of PPⅡ （0， 1.5， 3.0， 4.5， 6.0， 9.0， 18.0 mg·L^-1） on the in vitro proliferation of HepG2 cells was assessed using the methyl thiazolyl tetrazolium （MTT） assay. Colony formation ability of HepG2 cells was evaluated through a colony formation assay. Cell migration ability was assessed via a scratch assay. Lactate dehydrogenase （LDH） content in HepG2 cells was measured using a kit. Reactive oxygen species （ROS） levels in HepG2 cells were observed using a fluorescence inverted microscope. Malondialdehyde （MDA）， glutathione （GSH）， and free Fe²⁺ content in HepG2 cells were detected using respective kits. The mitochondrial ultrastructure in HepG2 cells was observed by transmission electron microscopy. The expression of ferroptosis-related proteins p53， solute carrier family 7 member 11 （SLC7A11）， glutathione peroxidase 4 （GPX4）， long-chain acyl-CoA synthetase 4 （ACSL4）， and transferrin receptor 1 （TFR1） in HepG2 cells was detected using Western blot. ResultCompared with the control group， the PPⅡ treatment groups showed significantly decreased survival rate of HepG2 cells in a dose-dependent manner （P<0.01）， significantly reduced number of cell colonies （P<0.01）， significantly shortened scratch healing distance， inverse correlation of the migration distance with drug concentration （P<0.01）， significantly increased LDH leakage in cells （P<0.01）， significantly enhanced relative fluorescence intensity of intracellular ROS， and significantly increased accumulation of lipid peroxide MDA （P<0.01）， decreased intracellular GSH content with increasing drug concentration （P<0.01）， and significantly enhanced fluorescence intensity of FeRhoNox-1 in cells （P<0.01）. Moreover， cells exhibited vacuolation， and mitochondria showed significant shrinkage with reduced or even disappeared cristae. Compared with the results in the control group， the expression of p53， ACSL4， and TFR1 proteins significantly increased， while the expression of SLC7A11 and GPX4 proteins significantly decreased in the PPⅡ treatment groups （P<0.05）. ConclusionIn summary， PPⅡ induces ferroptosis in HepG2 cells by regulating the p53/SLC7A11/GPX4 signaling axis， promoting ACSL4 expression and Fe³⁺ uptake， leading to an imbalance in the antioxidant system.

Paridis Rhizoma possesses the functions of clearing heat and detoxifying， alleviating swelling and relieving pain， cooling the liver and calming the convulsion. Saponins are the main active components of Paridis Rhizoma. Studies have shown that total saponins in Paridis Rhizoma have obvious inhibitory effect on solid tumors such as breast cancer， lung cancer， gastric cancer， and liver cancer and non-solid tumors such as leukemia. The saponins may exert the anti-tumor effects by inhibiting the proliferation， migration， and invasion of tumor cells， regulating cell cycle， inducing apoptotic and non-apoptotic death pathways， and regulating metabolism and tumor microenvironment. Furthermore， total saponins in Paridis Rhizoma showed anti-inflammatory， antioxidant， antimicrobial， hemostatic， and uterus-contracting activities. At the same time， they may induce apoptosis of normal cells， inflammation and oxidative stress， and metabolic disorders. In recent years， the reports of liver injury， reproductive injury， gastrointestinal injury， hemolysis， and other adverse reactions caused by total saponins in Paridis Rhizoma have been increasing. Pharmacokinetic studies have shown that there are significant differences in the metabolism of total saponins in Paridis Rhizoma administrated in different ways. Injection has a fast clearance rate， while oral administration may have hepatoenteric circulation. Meanwhile， due to the low solubility and activation of P-glycoprotein （P-gp） molecular pump， the prototype absorption， intestinal permeability， and recovery rate of total saponins in Paridis Rhizoma are poor， which affects the bioavailability. The bioavailability can be improved to some extent by preparing new dosage forms or new drug delivery systems with advanced technology. This paper reviews the pharmacological effect， pharmacokinetics， and adverse reactions of Rhizoma Paridis total saponins by searching the China National Knowledge Infrastructure （CNKI）， VIP， and Web of Science with ''Rhizoma Paridis total saponins'' as the keywords， hoping to provide references for the research， development， and clinical application of such components.

Objective To investigate the infectivity of hepatitis A virus(HAV)cell-adapted strain in a type Ⅰ interferon receptor-deficient mouse model.Methods The biological charateristics of HM175/18f were identified,including the viral protein expression and viral proliferation by indirect immunofluorescence,Western blot and real-time quantitative RT-PCR in vitro.Then,type Ⅰ interferon receptor-deficient A129 mice were infected with HM175/18f via intravenous injection.The viral RNA load in serum,feces and liver tissues of infected mice were detected to determine the replication of HAV in vivo.The level of serum alanine aminotransferase(ALT)and HE staining of liver tissues were used to evaluate liver injury.Additionally,the dynamic changes of HAV-specific IgG antibody was detected to assess the humoral immune response induced by HM175/18f.Results A129 mice infected with HM175/18f did not show obvious clinical symptoms,nor was the ALT level significantly elevated.However,viral RNA persisted in the liver tissue of infected mice until 42 days after infection.There was focal infiltration of lymphocytes and neutrophils in the liver tissue of infected mice,but no focal necrosis was observed.More importantly,HM175/18f infection caused significant viremia and sustained fecal virus shedding.In addition,HM175/18f induced a significant HAV-specific humoral immune response in A129 mice.Conclusion Our study has revealed the infectivity of HAV cell-adapted strain HM175/18f in type Ⅰ interferon receptor-deficient mice,and identified the attenuated characteristics of HM175/18f,which not only contributes to our understanding of the pathogenesis of HAV,but also expand the applications of a type Ⅰ interferon receptor-deficient mouse model in the study of hepatitis A.

Objective To investigate how maternal MTR gene polymorphisms and their interactions with periconceptional folic acid supplementation are associated with the incidence of ventricular septal defects(VSD)in offspring.Methods A case-control study was conducted,recruiting 426 mothers of infants with VSD under one year old and 740 mothers of age-matched healthy infants.A questionnaire survey collected data on maternal exposures,and blood samples were analyzed for genetic polymorphisms.Multivariable logistic regression analysis and inverse probability of treatment weighting were used to analyze the associations between genetic loci and VSD.Crossover analysis and logistic regression were utilized to examine the additive and multiplicative interactions between the loci and folic acid intake.Results The CT and TT genotypes of the maternal MTR gene at rs6668344 increased the susceptibility of offspring to VSD(P<0.05).The GC and CC genotypes at rs3768139,AG and GG at rs1050993,AT and TT at rs4659743,GG at rs3768142,and GT and TT at rs3820571 were associated with a decreased risk of VSD(P<0.05).The variations at rs6668344 demonstrated an antagonistic multiplicative interaction with folic acid supplementation in relation to VSD(P<0.05).Conclusions Maternal MTR gene polymorphisms significantly correlate with the incidence of VSD in offspring.Mothers with variations at rs6668344 can decrease the susceptibility to VSD in their offspring by supplementing with folic acid during the periconceptional period,suggesting the importance of periconceptional folic acid supplementation in genetically at-risk populations to prevent VSD in offspring.

We established an indirect ELISA method using Trichinella spiralis trehalase(TsTRE)protein expressed in prokaryotic cells.The TsTRE gene was amplified by RT-PCR and ligated into the pCold I plasmid,which was expressed in E.coli BL21 competent cells.The rTsTRE protein was purified through affinity column chromatography.The TsTRE protein was localized with immunofluorescence techniques,and the immunogenicity of rTsTRE was detected by westernblotting.Subse-quently,rTsTRE protein was used as a coating antigen to establish an indirect ELISA.We optimized the antigen-coating con-centration,serum dilution concentration,antigen-coating incubation time,type of blocking solution,blocking incubation time,HRP-labeled goat anti-rabbit IgG serum dilution concentration,HRP-labeled goat anti-rabbit IgG serum incubation time and response time of TMB.Subsequently,the critical value,repeatability,sensitivity,specificity and clinical detection rate of the ELISA were evaluated.Immunofluorescence indicated that trehalase was abundant in the rod-shaped body,tail and epidermis of Trichinella spiralis muscle larvae.Western-blot indicated that rTsTRE protein combined with the positive serum of mice infected with T.spiralis for 42 d;the band was approximately 60 kDa.The established indirect ELISA had a positive threshold of 0.384;the intra-run and inter-run coefficients of variation were 5.504％-7.630％ and 4.664％-9.929％,and did not exceed 10％.The lowest detectable titer was 1:1 280.No cross reaction was observed with antibodies to Clonorchissinensis,Schistosoma ja-ponicum,Ascaris suum,Toxocara gondii and Toxocara canis,and the clinical negative detection rate was 0％.Thus,we suc-cessfully expressed the rTsTRE protein.Moreover,the established indirect ELISA method using the TsTRE protein as the coating antigen had good repeatability,sensitivity,specificity and clinical detectability,and can be applied to the detection of clinical samples.

Objective:To investigate the construction and application value of a nomogram predictive model for the prognosis of rectal cancer liver metastases based on Surveillance, Epidemio-logy, and End Results (SEER) database.Methods:The retrospective cohort study was conducted. The clinicopathological data of 6 192 patients with rectal cancer liver metastases in the SEER database ( http://seer.cancer.gov/) and 312 patients who were admitted to The Second Affiliated Hospital of Naval Medical University January 2010 to December 2016 were collected. Of 6 192 patients, there were 3 592 males and 2 600 cases. There were 1 076 cases with age lower than 50 years, 2 862 cases with age as 50-69 years, 2 254 cases with age equal to or more than 70 years, respectively. Of 312 pati-ents, there were 177 males and 135 cases. There were 51 cases with age lower than 50 years, 155 cases with age as 50-69 years, 109 cases with age equal to or more than 70 years, respectively. Patients of the SEER database were set as the training set, and patients in The Second Affiliated Hospital of Naval Medical University were set as the validation set. Univariate and multivariate COX proportional hazards regression models were used to analyze risk factors associated with prognosis, and construct and verify the accuracy of nomogram predictive model for the prognosis of rectal cancer liver metas-tasis. The training set were used to construct the nomogram prediction model, and the validation set were used to verify its performance. Observation indicators: (1) prognostic factors analysis in patients with rectal cancer liver metastases; (2) construction and verificative of the predictive model for the prognosis of rectal cancer liver metastasis. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Comparison of ordinal data was analyzed using the rank sum test. The COX regression model was used for univariate and multivariate analyses. Kaplan-Meier method was used to calculate survival rates, and Log-Rank test was used for survival analysis. Results:(1) Prognostic factors analysis in patients with rectal cancer liver metastases. Results of multivariate analysis showed that age >50 years, TNM Ⅱ-Ⅳ stage, stage T3-T4, stage N1-N2, the number of lymph nodes dissected <12, tumor diameter >5.1 cm, positive carcinoembryonic antigen, peripheral nerve infiltration, radiotherapy and adjuvant chemotherapy, poorly differentiated or undifferented tumor were independent prognostic factors of patients ( P<0.05). (2) Construction and verification of the predictive model for the prognosis of rectal cancer liver metastasis. A nomogram predictive model for the prognosis of rectal cancer liver metastasis was constructed based in the multivariate analysis. The C-index of the nomogram predictive model was 0.91, with area under the curve as 0.726, indicating a good discriminant ability. Results of the calibration curve in validation dataset showed that the colorectal cancer survival rate predicted by the nomogram predictive model was consistent with the actual survival rate. Conclusion:The nomogram predictive model can accurately predict the survival probability of patients with rectal cancer liver metastases.

Objective To analyze the characteristics of imported malaria epidemic from overseas in Wuhan, to explore the management mechanism of on-site cases, and to accumulate experience for the treatment of imported malaria in large cities after malaria elimination. Methods The epidemiological data on imported malaria from abroad during the period of malaria elimination (2010-2019) in Wuhan were collected. The gender, age and severe illness-related factors of the cases were analyzed. Based on the characteristics of the epidemic and the current situation of prevention and control, the content and experience of the “Municipal-District 24-7” case mechanism were discussed. Results The medical resources in Wuhan were the best in the central region, resulting in a large number of imported malaria cases, with a total of 474 cases reported from 2010 to 2019 (40.79% of the total number of cases in Hubei Province), including 359 cases of falciparum malaria, 36 severe cases and one death (the death rate was 0.28%). The patients were mainly young and middle-aged men aged 20 to 49 years old (97.26%). There were many referral cases (40.30%), and there was no seasonal clustering of cases reported. The undiagnosed proportion at the first visit was 44.85%, and the time of attack-diagnosis was 4 days or more in 61.00% of cases. The occurrence of severe cases was related to unconfirmed diagnosis at the first visit (χ²=35.46, P<0.001) and attack-diagnosis time (Z=-6.49, P<0.001). Conclusion Imported malaria occurs frequently in Wuhan, mainly falciparum malaria. However, “Municipal-District 24-7” case mechanism has effectively curbed the occurrence of severe and death cases and provided valuable experience for case management in similar cities in China.