ObjectiveTo explore the molecular mechanism of Buzhong Yiqitang in attenuating cisplatin resistance of non-small cell lung cancer （NSCLC） cells （A549/DDP） by regulating endoplasmic reticulum stress （ERS） via the nuclear factor E₂-related factor 2 （Nrf2）/reactive oxygen species （ROS）/double-stranded RNA-activated protein kinase R （PKR）-like endoplasmic reticulum kinase （PERK）/CCAAT enhancer-binding protein homologous protein （CHOP） signaling pathway. MethodsSprague Dawley （SD） rats were used to prepare blank serum and Buzhong Yiqitang-containing serum samples， and A549/DDP cells were sub-cultured and randomly allocated into 9 groups： Blank （10% blank rat serum medium）， model （10% blank rat serum medium+20 mg·L^-1 cisplatin）， traditional Chinese medicine（TCM） （10% Buzhong Yiqitang-containing rat serum medium+20 mg·L^-1 cisplatin）， TBHQ （10% blank rat serum medium+5 μmol·L^-1 TBHQ+20 mg·L^-1 cisplatin）， TBHQ+TCM （10% Buzhong Yiqitang-containing rat serum medium+5 μmol·L^-1 TBHQ+20 mg·L^-1 cisplatin）， NAC （10% blank rat serum medium+600 μmol·L^-1 NAC+20 mg·L^-1 cisplatin）， NAC+TCM （10% Buzhong Yiqitang-containing rat serum medium+600 μmol·L^-1 NAC+20 mg·L^-1 cisplatin）， Salubrinal （10% blank rat serum medium+20 μmol·L^-1 Salubrinal+20 mg·L^-1 cisplatin）， and Salubrinal+TCM （10% Buzhong Yiqitang-containing rat serum medium+20 μmol·L^-1 Salubrinal+20 mg·L^-1 cisplatin）. The median inhibitory concentration （IC₅₀） of cisplatin in each group was determined by the cell counting kit-8 （CCK-8） method. The ROS level was detected by flow cytometry. The ultrastructure of endoplasmic reticulum （ER） was observed by transmission electron microscopy. Western blot was employed to determine the protein levels of Nrf2， phosphorylated （p）-Nrf2， CHOP， PERK， p-PERK， eukaryotic translation initiation factor 2α （eIF2α）， p-eIF2α， and activated transcription factor 4 （ATF4）. The fluorescence intensity of CHOP and p-PERK was detected by confocal fluorescence localization. ResultsCompared with the model group， the TCM group showed a decrease in IC₅₀ of cisplatin in A549/DDP cells （P<0.01）. TBHQ， NAC， and Salubrinal groups showed increases in IC₅₀ of cisplatin in A549/DDP cells （P<0.01）. TCM combined with TBHQ， NAC， and Salubrinal reduced the IC₅₀ （P<0.01）. Compared with that in the blank group， the ROS level in the model group elevated （P<0.01）. Compared with that in the model group， the ROS level in the TCM group elevated （P<0.01）. The ROS levels in the TBHQ， NAC， and Salubrinal groups were lower than that in the model group （P<0.01）. The combinations of TBHQ， NAC， and Salubrinal with TCM raised the ROS levels of A549/DDP cells （P<0.01）. A flat saclike and neatly arranged ER structure was observed in the blank group， and slight expansion of ER was observed in the model group. Significant expansion of ER was observed in the TCM group. The expansion of ER was not obvious in the TBHQ， NAC， and Salubrinal groups but significant after TBHQ， NAC， and Salubrinal were combined with TCM. CHOP and p-PERK showed higher fluorescence intensity in the model group than in the blank group （P<0.01）， and the fluorescence signal intensity in the TCM group was higher than that in the model group （P<0.01）. The fluorescence intensity in the TBHQ， NAC， and Salubrinal groups was lower than that in the model group （P<0.01）. The fluorescence intensity in the groups of TBHQ， NAC， and Salubrinal combined with TCM was higher than that in corresponding groups without TCM （P<0.01）. Compared with those in the blank group， the expression levels of Nrf2 and p-Nrf2 were up-regulated in the model group （P<0.05）. Compared with the model group， the TCM group showed down-regulated expression levels of Nrf2 and p-Nrf2 （P<0.05）. TBHQ， NAC， and Salubrinal increased the expression levels of Nrf2 and p-Nrf2 （P<0.05）， while their combinations with TCM decreased the expression levels of Nrf2 and p-Nrf2 compared with the corresponding groups without TCM （P<0.01）. There were no significant differences in the expression levels of PERK and eIF2α between groups. The expression levels of CHOP， p-PERK/PERK， p-eIF2α/eIF2α， and ATF4 were up-regulated in the model group compared with those in the blank group （P<0.05）. Compared with the model group， the TCM group showed up-regulated expression levels of CHOP， p-PERK/PERK， p-eIF2α/eIF2α， and ATF4 （P<0.05）， while the TBHQ， NAC， and Salubrinal groups showed down-regulated expression levels （P<0.05）. The groups of TBHQ， NAC， and Salubrinal combined with TCM had higher expression levels than the groups without TCM （P<0.01）. ConclusionBuzhong Yiqitang regulates ERS via the Nrf2/ROS/PERK/CHOP signaling pathway to attenuate cisplatin resistance in NSCLC.

ObjectiveTo explore the molecular mechanism of Buzhong Yiqitang in attenuating cisplatin resistance in non-small cell lung cancer （NSCLC） by inducing ferroptosis via poly（rC）-binding protein 1 （PCBP1）. MethodsThe serum containing Buzhong Yiqitang was prepared and cisplatin-resistant human non-small cell lung cancer （NSCLC） cells （A549/DDP） were cultured and randomly grouped as follows： Blank （10% blank serum）， model （10% blank serum+20 mg·L^-1 cisplatin）， Buzhong Yiqitang （10% serum containing Buzhong Yiqitang+20 mg·L^-1 cisplatin）， Fe-1 （10% blank serum+20 mg·L^-1 cisplatin+5 μmol·L^-1 Fe-1）， and Buzhong Yiqitang+Fe-1 （10% serum containing Buzhong Yiqitang+20 mg·L^-1 cisplatin+5 μmol·L^-1 Fe-1）. Firstly， PCR Array was used to screen ferroptosis-related genes regulated by Buzhong Yiqitang， and PCBP1 was identified as the target for studying the attenuation of cisplatin resistance by Buzhong Yiqitang. Subsequently， the median inhibitory concentration （IC₅₀） of cisplatin in each group was determined by the cell counting kit-8 （CCK-8） method and the resistance index （RI） was calculated. The ultrastructure of A549/DDP cells in each group was observed by transmission electron microscopy. The protein levels of PCBP1 and glutathione peroxidase 4 （GPX4） were determined by Western blot. The lipid reactive oxygen species （ROS） content in each group was determined by the C11-BODIRY 581/591 fluorescence probe. The ferrous ion assay kit was used to measure the ferrous ion content in each group. The malondialdehyde （MDA） assay kit was used to determine the MDA content in each group. ResultsCompared with model group， the IC₅₀ of cisplatin and the RI of A549/DDP cells decreased in the Buzhong Yiqitang group （P<0.05） but increased in the Fe-1 group （P<0.05）. The IC₅₀ of cisplatin and the RI of A549/DDP cells in the Buzhong Yiqitang+Fe-1 group were lower than those in the Fe-1 group （P<0.05）. Compared with the model group， the Buzhong Yiqitang group showed obvious mitochondrial ferroptosis， while the mitochondrial damage became less obvious after Fe-1 treatment. Compared with that in the Fe-1 group， the mitochondrial ferroptosis was aggravated after the intervention with Buzhong Yiqitang. Compared with blank group， the model group showed down-regulated expression levels of PCBP1 and GPX4 （P<0.05） and increased content of lipid ROS， ferrous ions， and MDA （P<0.05） in A549/DDP cells. Compared with model group， the Buzhong Yiqitang group showed down-regulated expression levels of PCBP1 and GPX4 （P<0.05） and increased content of lipid ROS， ferrous ions， and MDA （P<0.05）， while the Fe-1 group showed up-regulated expression levels of PCBP1 and GPX4 （P<0.05） and reduced content of lipid ROS， ferrous ions， and MDA （P<0.05）. Compared with the Fe-1 group， the Buzhong Yiqitang+Fe-1 group showed down-regulated expression levels of PCBP1 and GPX4 and increased content of lipid ROS， ferrous ions， and MDA （P<0.05）. ConclusionBuzhong Yiqitang attenuated cisplatin resistance in NSCLC by regulating PCBP1 to induce ferroptosis.

ObjectiveTo investigate the mechanism of Buzhong Yiqitang in attenuating cisplatin resistance in non-small cell lung cancer by observing the effects of Buzhong Yiqitang on endoplasmic reticulum stress-related molecules in human lung adenocarcinoma cells （A549） and cisplatin-resistant cells in human lung adenocarcinoma cells （A549/DDP） via the nuclear factor E₂-related factor 2（Nrf2）/reactive oxygen species（ROS） pathway. MethodsThe serum containing Buzhong Yiqitang was prepared and A549 cells and A549/DDP cells were cultured. The cells were randomized into groups A （A549 cells+blank serum）， B （A549 cells+20 mg·L^-1 cisplatin+blank serum）， C （A549 cells+20 mg·L^-1 cisplatin+10% Buzhong Yiqitang-containing serum）， D （A549/DDP cells+blank serum）， E （A549/DDP cells+20 mg·L^-1 cisplatin+blank serum）， and F （A549/DDP cells+20 mg·L^-1 cisplatin+10% Buzhong Yiqitang-containing serum）. The cell counting kit-8 （CCK-8） method was used to detect the half maximal inhibitory concentration （IC₅₀） of cisplatin. The protein levels of Nrf2 and p-Nrf2 were determined by Western blotting. The DCFH-DA fluorescent probe was used to measure the content of reactive oxygen species （ROS） in each group. The protein levels of glucose-regulated protein 78 （GRP78）， activated transcription factor 6 （ATF6）， and C/EBP-homologous protein （CHOP） were determined by Western blot. ResultsCompared with group B， group C showed a reduction in IC₅₀ of cisplatin （P<0.05）， which held true in group E compared with group F （P<0.05）. Moreover， the IC₅₀ of cisplatin to A549/DDP cells was higher than that to A549 cells before and after Buzhong Yiqitang intervention （P<0.05）. Compared with group A， group B showed up-regulated protein levels of Nrf2 and p-Nrf2 （P<0.05）. Compared with group B， group C showed down-regulated protein levels of Nrf2 and p-Nrf2 （P<0.05）. Compared with group D， group E showed up-regulated protein levels of Nrf2 and p-Nrf2 （P<0.05）， which， however， were significantly down-regulated in group F （P<0.05）. The ROS content and the protein levels of GRP78， ATF6， and CHOP followed a descending trend of group C > group B > group A in A549 cells and group F > group E > group D in A549/DDP cells （P<0.05）. Moreover， the ROS content and the protein levels of GRP78， ATF6， and CHOP in A549 cells were higher than those in A549/DDP cells before and after Buzhong Yiqitang intervention （P<0.05）. ConclusionBuzhong Yiqitang may regulate endoplasmic reticulum stress via the Nrf2/ROS pathway to attenuate cisplatin resistance in non-small cell lung cancer.

In the process of tumor chemotherapy， the emergence of multi-drug resistance （MDR） has always been a thorny problem， which is a result of the joint action of the host， tumor cells， and the immune microenvironment. Tumor cells can escape the toxicity of chemotherapeutic drugs through multiple pathways， being easy to produce drug resistance. MDR greatly restricts the effect of chemotherapeutic drugs on tumor cells and affects their therapeutic effects. Traditional Chinese medicine （TCM） has the unique advantages of multi-target， multi-pathway and individualized treatment. The TCM treatment of tumors emphasizes regulating Yin and Yang， as well as reinforcing healthy Qi and dispelling pathogen. In recent years， TCM has demonstrated remarkable efficacy in the treatment of tumors and the amelioration of multi-drug resistance. TCM not only can target the phenomenon of MDR but also greatly weakens the side effects of the patients after the chemotherapy， thus improving the survival quality and rate of the patients. Accordingly， many patients adopt TCM as an adjuvant therapy during or after chemotherapy. The binding of TCM to targets can reverse the drug resistance of various tumors， which has become an emerging research highlight. From the regulatory mechanism of TCM on MDR of tumors， this paper introduces the mechanisms by which tumor cells continue to grow， proliferate， and metastasize by adjusting the intracellular drug concentration， altering or utilizing the tumor microenvironment， and affecting the cell death mode to achieve the resistance to chemotherapeutic drugs. In this regard， the active ingredients and compound prescriptions of TCM can increase the sensitivity of chemotherapeutic drugs by down-regulating drug transporters， improving the tumor microenvironment， and modulating the drug resistance pathways associated with apoptosis， autophagy， ferroptosis， or pyroptosis. The aim of this paper is to explore more clinical practical value of TCM in the treatment of tumors and provide exploratory ideas and a theoretical basis for the future research on tumors and MDR.

Objective To clone and express the heat shock cognate protein 20 (SjHsc20) of Schistosoma japonicum, and to preliminarily investigate its biological characteristics. Methods The target fragment of the SjHsc20 gene was amplified using PCR assay and cloned into the pET-28a(+) expression plasmid to generate the recombinant expression vector pET-28a(+)-SjH-sc20, which was then transformed into Escherichia coli BL21 (DE3) competent cells. The recombinant SjHsc20 (rSjHsc20) protein was induced with isopropyl β-D-thiogalactopyranoside (IPTG) and purified, and the expression of the rSjHsc20 protein was checked with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The immunogenicity of the rSjHsc20 protein was detected using Western blotting, and the transcriptional levels of SjHsc20 were quantified in S. japonicum worms at different developmental stages and in male and female adult worms using real-time quantitative PCR (RT-qPCR) assay. Thirty female BALB/c mice at ages 6 to 8 weeks were divided into three groups, including the rSjHsc20 immunization group, the PBS control group, and the ISA 206 adjuvant group, of 10 mice in each group. Mice in the rSjHsc20 immunization group were subcutaneously immunized with 20 μg rSjHsc20 on days 1, 15 and 31, and animals in the PBS control group were subcutaneously injected with the same volume of PBS on days 1, 15 and 31, while mice in the ISA 206 adjuvant group were subcutaneously immunized with the same volume of ISA 206 adjuvant on days 1, 15 and 31, respectively. All mice in each group were infected with (40 ± 2) S. japonicum cercariae via the abdomen 14 day following the last immunization. Levels of serum specific IgG and its subtypes IgG1 and IgG2 antibodies against rSjHsc20, and the serum titers of anti-rSjHsc20 antibody were detected in mice using indirect enzyme-linked immunosorbent assay (ELISA). All mice were sacrifice 42 days post-infection, and S. japonicum worms were collected from the hepatic portal vein and counted. The eggs per gram (EPG), worm burden reductions and egg burden reductions were estimated to evaluate the protective efficacy of the rSjHsc20 protein. Results The SjHsc20 gene had an open reading frame (ORF) with 756 bp in length and encoded 252 amino acids, and the rSjHsc20 protein had a relative molecular mass of approximately 29 kDa. The rSjHsc20 protein was recognized by the serum of mice infected with S. japonicum and the serum of mice immunized with the rSjHsc20 protein, indicating that rSjHsc20 had a good immunogenicity. There was a significant difference in the transcriptional levels of the SjHsc20 gene among the 7-day (1.001 4 ± 0.065 7), 12-day (2.268 3 ± 0.129 2), 21-day (1.378 5 ± 0.160 4), 28-day (1.196 4 ± 0.244 0), 35-day (1.646 3 ± 0.226 1), 42-day worms of S. japonicum (1.758 0 ± 0.611 1) (F = 38.45, P < 0.000 1), and the transcriptional level of the SjHsc20 gene was higher in the 12-day worms than in worms at other developmental stages (all P values < 0.000 1). The serum levels of anti-rSjHsc20 IgG antibody were 0.106 6 ± 0.010 7, 0.108 3 ± 0.010 4, and 0.553 2 ± 0.069 1 in the PBS control group, ISA 206 adjuvant group, and rSjHsc20 immunization group following the last immunization, respectively, and the serum levels of IgG1 antibody were 0.137 3 ± 0.054 0, 0.181 1 ± 0.096 8, and 1.765 8 ± 0.221 1, while the levels of IgG2a antibody were 0.280 3 ± 0.197 6, 0.274 0 ± 0.146 3, and 1.560 4 ± 0.106 0, respectively. There were significant differences in the serum levels of anti-rSjHsc20 IgG (F = 397.70, P < 0.000 1), IgG1 (F = 401.00, P < 0.000 1) and IgG2a antibodies (F = 229.70, P < 0.000 1) among the three groups, and the serum levels of anti-rSjHsc20 IgG, IgG1 and IgG2a antibodies were higher in the rSjHsc20 immunization group than in the PBS control group and the ISA 206 adjuvant group (all P values < 0.000 1). There was a significant difference in the IgG1/IgG2a ratio among the rSjHsc20 immunization group (1.177 2 ± 0.143 6), the PBS control group (0.428 4 ± 0.199 8) and the ISA 206 adjuvant group (0.559 9 ± 0.181 1) (F = 43.97, P < 0.000 1), and the IgG1/IgG2a ratio was > 1 in the rSjHsc20 immunization group, which was higher than in the PBS control group and the ISA 206 adjuvant group (both P values < 0.000 1). The titers of serum anti-rSjHsc20 antibody were all above 1∶16 384 in the rSjHsc20 immunization group following immunizations on days 1, 15 and 31, indicating that the rSjHsc20 protein had a strong immunogenicity. The mean worm burdens were (16.60±5.75), (15.80±5.58) worms per mouse and (14.40±5.75) worms per mouse in the PBS control group, the ISA 206 adjuvant group and the rSjHsc20 immunization group 42 days post-infection with S. japonicum cercariae (F = 0.50, P > 0.05), and the EPG were 68 370 ± 22 690, 67 972 ± 19 502, and 41 075 ± 13 251 in the PBS control group, the ISA 206 adjuvant group and the rSjHsc20 immunization group (F = 4.55, P < 0.05), with lower EPG in the PBS control group and the ISA 206 adjuvant group than in the rSjHsc20 immunization group (both P values < 0.05). Immunization with the rSjHsc20 protein resulted in a worm burden reduction of 13.25% and an egg burden reduction of 39.92% relative to the PBS control group. Conclusions SjHsc20 is successfully cloned and expressed, and the rSjHsc20 protein induces partial immunoprotective effects in mice, which provides a basis for deciphering the biological functions of SjHsc20 and assessing the potential of SjH-sc20 as a vaccine candidate.

Objective To predict the lymph node metastasis status of patients with invasive pulmonary adenocarcinoma by constructing machine learning models based on primary tumor radiomics, peritumoral radiomics, and habitat radiomics, and to evaluate the predictive performance and generalization ability of different imaging features. Methods A retrospective analysis was performed on the clinical data of 1 263 patients with invasive pulmonary adenocarcinoma who underwent surgery at the Department of Thoracic Surgery, Jiangsu Province Hospital, from 2016 to 2019. Habitat regions were delineated by applying K-means clustering (average cluster number of 2) to the grayscale values of CT images. The peritumoral region was defined as a uniformly expanded area of 3 mm around the primary tumor. The primary tumor region was automatically segmented using V-net combined with manual correction and annotation. Subsequently, radiomics features were extracted based on these regions, and stacked machine learning models were constructed. Model performance was evaluated on the training, testing, and internal validation sets using the area under the receiver operating characteristic curve (AUC), F1 score, recall, and precision. Results After excluding patients who did not meet the screening criteria, a total of 651 patients were included. The training set consisted of 468 patients (181 males, 287 females) with an average age of (58.39±11.23) years, ranging from 29 to 78 years, the testing set included 140 patients (56 males, 84 females) with an average age of (58.81±10.70) years, ranging from 34 to 82 years, and the internal validation set comprised 43 patients (14 males, 29 females) with an average age of (60.16±10.68) years, ranging from 29 to 78 years. Although the habitat radiomics model did not show the optimal performance in the training set, it exhibited superior performance in the internal validation set, with an AUC of 0.952 [95%CI (0.87, 1.00)], an F1 score of 84.62%, and a precision-recall AUC of 0.892, outperforming the models based on the primary tumor and peritumoral regions. Conclusion The model constructed based on habitat radiomics demonstrated superior performance in the internal validation set, suggesting its potential for better generalization ability and clinical application in predicting lymph node metastasis status in pulmonary adenocarcinoma.

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 &mu;m/year in women and 5.8 &mu;m/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

Viral infection can induce endoplasmic reticulum stress(ERS)and unfolded protein re-sponse(UPR)in host cells,resulting in perturbation of endoplasmic reticulum homeostasis.To e-lucidate the action mechanism of isochlorogenic acid A(IAA)in regulating peste des petits rumi-nant virus(PPRV)-induced ERS and UPR,MTT assay,indirect immunofluorescence assay and Western blot were used to evaluate the anti-PPRV activity of IAA,and the effects of IAA on PPRV-induced ERS and PERK signaling pathway were studied by Western blot and quantitative real-time PCR.The results showed that the PPRV replication and virus-induced cytopathic in LDG-2 cells were significantly inhibited,and the survival rate of virus-infected cells was significantly in-creased due to IAA treatment.Compared with the virus control group,the expression levels of GRP78 and p-eIF2α,the ratios of p-PERK/PERK and p-eIF2α/eIF2α in IAA treated PPRV-infec-ted cells were significantly decreased.The expression level of GADD153 significantly decreased at 24,36 h,and significantly increased at 48,60 h.Furthermore,treatment with ERS inhibitor 4-PBA could significantly suppress the expression levels of GRP78,PPRV-N protein and GADD153 in PPRV-infected cells,and the ratios of p-eIF2α/eIF2α and p-PERK/PERK in PPRV-infected cells were also significantly decreased caused by treatment with IAA or 4-PBA and IAA combination.These findings implicated that the PPRV-induced ERS could be alleviated by inhibiting activation of the PERK-eIF2α-GADD1 53 signaling pathway,which led to restriction of PPRV replication in host cells.

Viral infection can induce endoplasmic reticulum stress(ERS)and unfolded protein reac-tion(UPR)in host cells.This study aims to further explore the effects of ERS induced by pest des petits ruminants virus(PPRV)infection on UPR signaling pathway,virus replication and apopto-sis of host cells.MTT assay,indirect immunofluorescence assay(IFA)and Western blot were used to observe the proliferation of PPRV in goat kidney cells(LDG-2).Western blot and real-time flu-orescence quantitative PCR(qRT-PCR)were used to observe the effects of PPRV infection on the expression levels of GRP78,PERK and its downstream signal molecules,apoptosis-related proteins Bcl-2 and Bax.The result indicated that the cell survival rate was significantly declined with evident cytopathic effect at 36 h post-infection,and the expression level of PPRV-N protein tended to be elevated,and was significantly higher than that of cell control at 30 h post-infection.Meanwhile,the expression levels of GRP78,p-eIF2α and GADD153,the ratio of p-PERK/PERK and p-eIF2α/eIF2α were significantly increased.Moreover,the expression levels of PPRV-N protein,GRP78,p-eIF2α and GADD1 53,the ratio of p-eIF2α/eIF2α and p-PERK/PERK were significantly decreased in PPRV-infected cells due to 4-PBA treatment.The expression level of apoptosis-related Bcl-2 was down-regulated,Bax was up-regulated,and the ratio of Bcl-2/Bax was significantly decreased.Therefore,the activation of PERK/eIF2α/GADD153 signaling pathway could be induced by PPRV infection resulting in alleviating of virus-induced ERS,which is beneficial to viral replication.Bloc-king PPRV-induced ERS could inhibit the activation of PERK signaling pathway and virus replica-tion.PPRV infection and prolonged ERS can induce apoptosis of LDG-2 cells.

MTT assay,indirect immunofluorescence assay(IFA)and real-time fluorescence quanti-tative PCR(qRT-PCR)were used to observe the proliferation of PPRV in goat kidney cells(LDG-2).Western blot and qRT-PCR were used to evaluate the effects of PPRV infection on the expres-sion levels of TLR2,MyD88,NF-κB signaling pathway-related factors and their downstream in-flammatory factors.The results indicated that the significantly decreased cell survival rate and ob-vious cytopathic effect were observed at 36 h post PPRV infection,and the mRNA expression level of PPRV-N gene was significantly up-regulated.At the same time,the expression levels of TLR2,MyD88,p-p65 and p-IκBα,the ratio of p-p65/p65 and p-IκBα/IκBα and the mRNA expression levels of downstream inflammatory factors TNFα,IL-1β,IL-4 and IL-10 were significantly increased.Mo-reover,the expression levels of PPRV-N mRNA,TLR2,MyD88,p-p65 and p-IκBα,the ratio of p-p65/p65 and p-IκBα/IκBα and the mRNA expression levels of downstream inflammatory factors IL-1β and IL-4 in PPRV-infected cells were significantly decreased in the presence of the inhibitor C29 of TLR2.These findings implied that the TLR2/MyD88/NF-κBα signaling pathway can be activated by PPRV infection,which is beneficial to the replication and spread of the virus.Blocking down the activation of TLR2 can inhibit MyD88/NF-κB signaling pathway and viral replication in PPRV-infected cells.