1.Facilitators and barriers to work-related musculoskeletal disorder prevention behaviors among healthcare professionals: A comprehensive review
Haijing MA ; Su’e YUAN ; Hui ZHU ; Yujia CHEN ; Ping SONG ; Huiqin YU ; Yunxia LI
Journal of Environmental and Occupational Medicine 2026;43(3):387-394
Work-related musculoskeletal disorders (WMSDs) represent a significant occupational health challenge among healthcare professionals globally, posing substantial threats to physical and mental well-being as well as work sustainability. Adopting preventive behaviors—including ergonomic postural adjustments, optimized work-rest scheduling, proper use of protective and assistive equipment, and regular physical activity—is essential for mitigating the risk of WMSDs. Guided by the social ecological model, the review synthesized current evidence on the determinants of WMSDs preventive behaviors across four levels: intrapersonal characteristics, work environment conditions, interpersonal support, and policy/institutional factors. The findings suggest that higher educational attainment, favorable health-related behavioral patterns, optimized ergonomic work environments, adoption of supportive collaborative systems, strong organizational support, as well as policy safeguards facilitate preventive behavior adoption. Conversely, limited prevention-related knowledge, low risk perception, insufficient physical activity, excessive workload, lack of appropriate protective equipment, inadequate ergonomic training, a prevailing culture of presenteeism, and inadequate policy implementation constitute significant barriers. Multi-dimensional intervention strategies targeting these determinants are warranted to enhance preventive behaviors, reduce the risk of WMSDs, and strengthen occupational health protection for healthcare professionals.
2.Exploration on effects of Bushen Antai Mixture on placental oxidative damage in mice with RSA investigation based on Nrf2/HO-1/NF-κB signaling pathways
Haijing CHU ; Chengcheng LIANG ; Zhe LI ; Heng HU ; Jing YU ; Jijun CHU
International Journal of Traditional Chinese Medicine 2025;47(4):494-500
Objective:To observe the effects of Bushen Antai Mixture on nuclear transcription factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1)/nuclear transcription factor-κB (NF-κB) in placental tissue of recurrent spontaneous abortion (RSA) mice.Methods:The CBA/J mice (female) and DBA/2 (male), CBA/J mice (female) and BALB/c (male) were caged at a ratio of 2 : 1 to establish RSA and normal pregnant mice, respectively. The next morning, the vaginal plug was found or the sperm was seen under the microscope as the successful modeling, which was counted as the first day of pregnancy. CBA/J×BALB/c mice were set as normal group, and the RSA model pregnant mice were divided into model group, progesterone group, and Bushen Antai Mixture low-, medium-, and high-dosage groups using a random number table method, with 6 mice in each group. The normal group and the model group were given distilled water by gavage. Bushen Antai Mixture low-, medium-, and high-dosage groups were given 3.9 g/kg, 11.7 g/kg and 23.4 g/kg Bushen Antai Mixture by gavage. The progesterone group was given progesterone capsule aqueous solution 26 mg/kg by gavage for 14 consecutive days. The embryo loss rate of mice was calculated. The pathological changes of placental tissues were observed by HE staining. The expressions of Nrf2, HO-1 and NF-κB protein and mRNA in placental tissues were detected by Western blot and RT-qPCR.Results:Compared with the model group, the embryo loss rate of mice in the Bushen Antai Mixture low-, medium-, and high-dosage groups and the progesterone group significantly decreased ( P<0.05, P<0.01); the pathological morphology of placental tissue improved; the expressions of Nrf2, HO-1 protein and mRNA in placental tissue significantly increased ( P<0.05, P<0.01), and the expression of NF-κB protein and mRNA significantly decreased ( P<0.05, P<0.01). Conclusion:Bushen Antai Mixture may may treat RSA by activating the Nrf2/HO-1 pathway, inhibiting NF - κB expression, and improving oxidative stress and inflammatory response in the placental tissue of RSA pregnant mice.
3.Yijingtang Reduces Ovarian Inflammatory Responses in Rat Model of Diminished Ovarian Reserve via TLR4/MyD88/NF-κB Signaling Pathway
Heng HU ; Jijun CHU ; Zhe LI ; Haijing CHU ; Jing YU ; Chengcheng LIANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(11):20-30
ObjectiveTo investigate the effect and mechanism of Yijingtang (YJT) in treating diminished ovarian reserve (DOR) in rats by regulating the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway. MethodsFifty female SD rats with normal estrous cycles were randomly allocated into blank, model, low- and high-dose (12.579 and 25.158 g·kg-1, respectively) YJT, and dehydroepiandrosterone (7.487 5 mg·kg-1) groups, with 10 rats in each group. The rats in other groups except the blank group were administrated with the tripterygium glycosides tablet suspension (5 mg·kg-1) by gavage for 14 days for the modeling of DOR. The rats in the drug treatment groups were administrated with corresponding drugs by gavage from day 15 for 30 consecutive days, and those in the blank and model groups received equal volumes of distilled water. The vaginal exfoliated cell smears were observed to assess the changes in the estrous cycle. The wet weight of bilateral ovaries was weighed for calculation of the ovarian index. Hematoxylin-eosin staining was performed to observe the histopathological changes in the ovaries and the proportions of follicles at various levels were calculated. The serum levels of sex hormones [follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and anti-Müllerian hormone (AMH)] and inflammatory factors [tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and interleukin-10 (IL-10)] were determined by enzyme-linked immunosorbent assay. Real-time quantitative polymerase chain reaction(Real-time PCR) was conducted to determine the mRNA levels of TLR4, MyD88, NF-κB profilin α (IκBα), NF-κB and inflammatory factors in the ovarian tissue. Western blot was employed to measure the protein levels of factors related to the TLR4/MyD88/NF-κB signaling pathway in the ovarian tissue. Immunofluorescence (IF) was used to detect the nuclear translocation of NF-κB p65 in the ovarian tissue. ResultsCompared with the blank group, the model group showed disturbed estrous cycles, increased inflammatory infiltration in the ovarian tissue, decreases in ovarian index and proportion of presinusoidal follicles, and an increase in the proportion of atretic follicles (P<0.05, P<0.01). In addition, the model group showed elevated serum levels of FSH, LH, TNF-α, and IL-1β, up-regulated mRNA levels of TLR4, MyD88, IκBα, NF-κB, TNF-α, and IL-1β and protein levels of TLR4, MyD88, p-IκBα, and p-NF-κB p65 (P<0.01), lowered serum levels of AMH, E2, and IL-10, down-regulated mRNA level of IL-10 (P<0.01), and massive nuclear translocation of NF-κB p65 in the ovarian tissue. Compared with the model group, dehydroepiandrosterone and low and high doses of YJT restored the disturbed estrous cycle, reduced inflammatory infiltration in the ovarian tissue, increased the ovarian index (P<0.01), and changed the follicular composition ratio (P<0.01). Furthermore, the drugs lowered the serum levels of FSH, LH, TNF-α, and IL-1β, down-regulated the mRNA levels of TLR4, MyD88, IκBα, NF-κB, TNF-α, and IL-1β and the protein levels of TLR4, MyD88, p-IκBα, and p-NF-κB p65 (P<0.05, P<0.01), raised the serum levels of AMH, E2, and IL-10, up-regulated the mRNA level of IL-10 (P<0.05, P<0.01), and reduced the nuclear translocation of NF-κB p65 in the ovarian tissue. ConclusionYJT may inhibit the release and expression of inflammatory factors by regulating the TLR4/MyD88/NF-κB signaling pathway to attenuate the inflammatory responses in the ovarian tissue, thereby improving the ovarian function in DOR rats.
4.Yijingtang Reduces Ovarian Inflammatory Responses in Rat Model of Diminished Ovarian Reserve via TLR4/MyD88/NF-κB Signaling Pathway
Heng HU ; Jijun CHU ; Zhe LI ; Haijing CHU ; Jing YU ; Chengcheng LIANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(11):20-30
ObjectiveTo investigate the effect and mechanism of Yijingtang (YJT) in treating diminished ovarian reserve (DOR) in rats by regulating the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway. MethodsFifty female SD rats with normal estrous cycles were randomly allocated into blank, model, low- and high-dose (12.579 and 25.158 g·kg-1, respectively) YJT, and dehydroepiandrosterone (7.487 5 mg·kg-1) groups, with 10 rats in each group. The rats in other groups except the blank group were administrated with the tripterygium glycosides tablet suspension (5 mg·kg-1) by gavage for 14 days for the modeling of DOR. The rats in the drug treatment groups were administrated with corresponding drugs by gavage from day 15 for 30 consecutive days, and those in the blank and model groups received equal volumes of distilled water. The vaginal exfoliated cell smears were observed to assess the changes in the estrous cycle. The wet weight of bilateral ovaries was weighed for calculation of the ovarian index. Hematoxylin-eosin staining was performed to observe the histopathological changes in the ovaries and the proportions of follicles at various levels were calculated. The serum levels of sex hormones [follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and anti-Müllerian hormone (AMH)] and inflammatory factors [tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and interleukin-10 (IL-10)] were determined by enzyme-linked immunosorbent assay. Real-time quantitative polymerase chain reaction(Real-time PCR) was conducted to determine the mRNA levels of TLR4, MyD88, NF-κB profilin α (IκBα), NF-κB and inflammatory factors in the ovarian tissue. Western blot was employed to measure the protein levels of factors related to the TLR4/MyD88/NF-κB signaling pathway in the ovarian tissue. Immunofluorescence (IF) was used to detect the nuclear translocation of NF-κB p65 in the ovarian tissue. ResultsCompared with the blank group, the model group showed disturbed estrous cycles, increased inflammatory infiltration in the ovarian tissue, decreases in ovarian index and proportion of presinusoidal follicles, and an increase in the proportion of atretic follicles (P<0.05, P<0.01). In addition, the model group showed elevated serum levels of FSH, LH, TNF-α, and IL-1β, up-regulated mRNA levels of TLR4, MyD88, IκBα, NF-κB, TNF-α, and IL-1β and protein levels of TLR4, MyD88, p-IκBα, and p-NF-κB p65 (P<0.01), lowered serum levels of AMH, E2, and IL-10, down-regulated mRNA level of IL-10 (P<0.01), and massive nuclear translocation of NF-κB p65 in the ovarian tissue. Compared with the model group, dehydroepiandrosterone and low and high doses of YJT restored the disturbed estrous cycle, reduced inflammatory infiltration in the ovarian tissue, increased the ovarian index (P<0.01), and changed the follicular composition ratio (P<0.01). Furthermore, the drugs lowered the serum levels of FSH, LH, TNF-α, and IL-1β, down-regulated the mRNA levels of TLR4, MyD88, IκBα, NF-κB, TNF-α, and IL-1β and the protein levels of TLR4, MyD88, p-IκBα, and p-NF-κB p65 (P<0.05, P<0.01), raised the serum levels of AMH, E2, and IL-10, up-regulated the mRNA level of IL-10 (P<0.05, P<0.01), and reduced the nuclear translocation of NF-κB p65 in the ovarian tissue. ConclusionYJT may inhibit the release and expression of inflammatory factors by regulating the TLR4/MyD88/NF-κB signaling pathway to attenuate the inflammatory responses in the ovarian tissue, thereby improving the ovarian function in DOR rats.
5.Ac-SDKP antagonizes lung fibrosis through EGFR/STAT3 pathway in silicosis rats
Wenli LI ; Lu LIU ; Yi HE ; Nana YAO ; Haijing DENG ; Ye QIAN
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(10):721-727
Objective:To examine the regulatory effects of a potential antifibrotic tetrapeptide called N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) on the expression of epidermal growth factor (EGFR) and signal transducer and activator of transcription 3 (STAT3) in lung tissues with fibrosis induced by silicosis in rats. This study aims to explore the potential therapeutic benefits of Ac-SDKP in the prevention and treatment of fibrotic lung diseases associated with silicosis.Methods:In January 2024, disease targets and Ac-SDKP active ingredients were predicted through GeneCards (https://www.genecards.org) and OMIM (https://www.omim.org) databases. Using R 4.2.1 software, we identified overlapping targets between pulmonary fibrosis and AC-SDKP. Cytoscape 3.10.2 was employed to visualize interactions between active chemical components and these targets, followed by GO enrichment analysis and KEGG pathway analysis using R 4.2.1. Forty healthy adult Wistar rats were selected to establish silicosis models through single-dose gavage with 50 mg/ml silica suspension (1. 0 ml per rat). The rats were randomly divided into four groups: model control group (4 weeks), silicosis model group (4 weeks), Ac-SDKP preventive treatment group (acquired via intraperitoneal injection of a micro-release pump containing Ac-SDKP [800 μg/ (kg·d) ] during modeling, maintained for 4 weeks), and Ac-SDKP anti-fibrosis treatment group (acquired via intraperitoneal injection of the same pump after 2 weeks of modeling, continued maintenance for 2 weeks). Each group contained 10 rats. The pathological changes in rat lung tissues were observed. Western blot technology was used to detect the protein expression levels of α-smooth muscle actin (α-SMA), epidermal growth factor receptor (EGFR), signal transduction and activation transcription factor 3 (STAT 3), caspase 3, and caspase 8 in lung tissues. Immunohistochemical techniques were employed to assess the expressions of EGFR, STAT3, caspase 3, and caspase 8. Overall differences between groups were compared using one-way ANOVA.Results:Compared with the control group in the silicosis model, rats in the 4-week group exhibited significant fibrotic nodules. The lung tissues of these rats showed statistically significant increases in α-SMA, EGFR, STAT 3, Caspase 3, and Caspase 8 protein expression ( P<0.05). In contrast, the Ac-SDKP prevention and anti-fibrosis treatment group demonstrated markedly reduced expression levels of these proteins compared to the 4-week silicosis model group, with statistically significant differences ( P<0.05). Immunohistochemical staining revealed that brownish-yellow expression of EGFR, STAT3, Caspase3, and Caspase8 was significantly enhanced in silicotic nodules within the silicosis model group. Conversely, this brownish-yellow expression was notably decreased in the Ac-SDKP prevention and anti-fibrosis treatment group compared to the 4-week silicosis model group. Conclusion:Ac-SDKP may exert antifibrotic effects on the lungs of rats with silicosis by regulating the EGFR/STAT3 pathway.
6.Plate and cannulated screw double-column fixation for complex talar neck fractures
Guixin WANG ; Hongbin CAO ; Nan LI ; Jun LIANG ; Haijing HUANG ; Jinquan HE
Chinese Journal of Orthopaedics 2025;45(8):485-491
Objective:To explore the clinical effect of treating complex talar neck fractures with double-column fixation using plates and cannulated screws.Methods:A retrospective analysis was performed on the data of 13 patients with complex talar neck fractures treated with double-column fixation using plates and cannulated screws at Tianjin Hospital, Tianjin University from June 2019 to November 2023. There were 9 males and 4 females, with an age of 42.1±17.7 years (range, 15-66 years). There were 5 cases on the left and 8 cases on the right. Four cases were caused by traffic accidents, 8 by falling from a height, and 1 by a heavy object injury. According to the Hawkins classification, there were 12 cases of type II and 1 case of type III talar neck fractures. All the fractures were comminuted, including 12 cases of talar neck combined with talar body, and 3 cases combined with subluxation of subtalar joint. The time from injury to surgery was 3.3±1.6 d (range, 1-6 d). All patients were treated with anteromedial combined anterolateral approach, plate and cannulated screw double-column fixation pattern. The healing time of fractures and the occurrence of complications were recorded. Postoperative anteroposterior and lateral X-ray images were taken to assess the quality of fracture reduction based on the presence or absence of step-offs and angulation after reduction of fractures at the neck or body of the talus. The functional outcome was evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale.Results:All 13 patients were followed up for 33.8±15.2 months (range, 12-53 months). All fractures healed, and the healing time was 17.2±2.8 weeks (range, 13-23 weeks). Postoperative X-ray evaluation showed that 10 cases had anatomical reduction and 3 cases had near-anatomical reduction. After operation, there was no loosening or breakage of implant, loss of fracture reduction, irritation of skin and soft tissue by internal fixation. The AOFAS score was 88.1±13.0 points (range, 48-100 points), with 9 excellent cases, 3 good cases, and 1 poor case. Superficial skin necrosis in one surgical incision healed after dressing exchange. At the 1-year follow-up after surgery, 1 case developed avascular necrosis of the talus without collapse. And at the last follow-up (postoperative 13 to 53 months), 5 cases developed post-traumatic arthritis.Conclusion:Plate and cannulated screw double-column fixation in the treatment of complex talar neck fractures can achieve satisfactory reduction and strong fixation effects, which is beneficial in reducing complications related to poor reduction.
7.Effects of Bushen Antai Mixture on Maternal and Foetal Interface Angiogenesis in Recurrent Spontaneous Abortion Mice Based on the VEGF/Hippo/YAP Pathway
Zhe LI ; Chengcheng LIANG ; Haijing CHU ; Heng HU ; Jing YU ; Jijun CHU
Chinese Journal of Information on Traditional Chinese Medicine 2025;32(4):107-112
Objective To observe the effects of Bushen Antai Mixture on angiogenesis at the maternal fetal interface in recurrent spontaneous abortion(RSA)mice;To explore its mechanism in treating RSA based on the VEGF/Hippo/YAP pathway.Methods RSA mouse model and normal pregnancy mouse were constructed using Clark classic method.RSA model mice were randomly divided into model group,progesterone group,Bushen Antai Mixture low-,medium-and high-dosage groups,and normal pregnant mice were used as normal group,with 10 mice in each group.Starting from the first day of pregnancy,each medication group was given the corresponding medication by gavage for 15 days.The absorption rate of mouse embryos was calculated,the morphology of decidual tissue were observed by HE staining,the mRNA and protein expression of VEGF and Hippo/YAP pathway-related molecules of decidual tissue were detected by RT-qPCR and Western blot.Results Compared with the normal group,the absorption rate of embryos in the model group significantly increased(P<0.01),the arrangement of decidual tissue cells were disordered,edematous and degenerated,some nuclei disappeared,the vascular density decreased,the mRNA expressions of VEGF,Yes associated protein(YAP),large tumor suppressor factor(LATS)1 and LATS2 in decidual tissue significantly decreased(P<0.01),the protein expression of VEGF decreased(P<0.01),and the protein expressions of p-YAP/YAP and p-LATS/LATS significantly increased(P<0.01).Compared with the model group,the absorption rate of embryos in each dosage group of Bushen Antai Mixture was significantly reduced(P<0.05,P<0.01),the cells in the decidual tissue were arranged in an orderly manner,and edema degeneration was reduced,the mRNA expressions of VEGF,YAP,LATS1 and LATS2 in decidual tissue significantly increased(P<0.05,P<0.01),and the protein expression of VEGF significantly increased(P<0.05,P<0.01),the protein expressions of p-YAP/YAP and p-LATS/LATS decreased(P<0.05,P<0.01).Conclusion Bushen Antai Mixture can promote the expressions of VEGF,YAP,LATS by activating VEGF/Hippo/YAP signaling pathway,promote angiogenesis at the maternal-fetal interface,reduce the pregnancy loss rate,and play a therapeutic effect of RSA.
8.Value of expression profile of mitochondrial ribosomal large subunit protein 13/BCL2-related protein A1/TP53 apoptosis-inducing protein 1 in serum in predicting chemotherapy response of triple-negative breast cancer and its immune regulatory mechanism
Haijing XIE ; Zhenzhong DENG ; Zhiyong YANG ; Shuqin LI
Journal of Clinical Medicine in Practice 2025;29(20):33-39
Objective To investigate the relationships of the mRNA expression levels of mitochon-drial ribosomal large subunit protein 13(MRPL13),BCL2-associated protein A1(BCL2A1)and TP53 apoptosis-inducing protein 1(TP53AIP1)in the serum of breast cancer patients with their chemotherapy efficacy as well as immune function.Methods A total of 148 triple-negative breast cancer patients undergoing chemotherapy were selected as the study subjects.Based on chemotherapy efficacy,they were divided into responsive group(97 cases)and non-responsive group(51 cases).Sixty healthy individuals undergoing physical examinations during the same period were selected as the control group.The mRNA expression levels of MRPL13,BCL2A1 and TP53AIP1 in the serum of patients were detected.The concentrations of immunoglobulin M(IgM),immunoglobulin G(IgG)and im-munoglobulin A(IgA)in the serum of patients were measured,and the proportions of CD4+and CD8+cells in whole blood were determined.The mRNA expression levels of MRPL13,BCL2A1 and TP53AIP1 were compared between the breast cancer group and the control group.The mRNA ex-pression levels of MRPL13,BCL2A1 and TP53AIP1 were compared between the responsive and non-responsive groups.The differences in immune function indicators before and after chemotherapy be-tween the responsive and non-responsive groups,were compared.The correlations of the mRNA ex-pression levels of MRPL13,BCL2A1 and TP53AIP1 with immune indicators were analyzed.Factors influencing chemotherapy efficacy were screened.Results The mRNA expression levels of MRPL13 and BCL2A1 in the breast cancer group were higher than those in the control group,while the mRNA expression level of TP53AIP1 was lower,with statistically significant differences(P<0.05).In the responsive group,the mRNA expression levels of MRPL13 and BCL2A1 were lower than those in the non-responsive group,while the mRNA expression level of TP53AIP1 was higher,with statistically significant differences(P<0.05).After chemotherapy,the IgM concentration in the responsive group was higher than that in the non-responsive group,with a statistically significant difference(P<0.05).The proportion of CD8+cells in the responsive group was lower than that in the non-responsive group,with a statistically significant difference(P<0.05).The mRNA expres-sion level of MRPL13 was positively correlated with IgM,IgG and CD8+(r=0.672,0.716,0.824,P<0.05).The mRNA expression level of BCL2A1 was positively correlated with IgA and CD4+(r=0.654,0.862,P<0.05).The mRNA expression level of TP53AIP1 was negatively cor-related with CD4+and CD8+(r=-0.846,-0.792,P<0.05).High expressions of MRPL13 and BCL2A1 were independent risk factors for chemotherapy efficacy in breast cancer patients(P<0.05),while high expression of TP53AIP1 was protective factor(P<0.05).Conclusion The mRNA expression levels of MRPL13,BCL2A1 and TP53AIP1 in the serum of triple-negative breast cancer patients undergoing chemotherapy are correlated with the levels of IgM,IgG and IgA,the proportions of CD4+and CD8+T cells,and chemotherapy efficacy.High expression of MRPL13 and BCL2A1 are independent risk factors for poor chemotherapy efficacy,while high expression of TP53AIP1 is a protective factor.
9.Construction and biological characterization of a dual sagA/aroA gene deletion mutant strain of donkey-derived Streptococcus equi subsp. equi
Bing LIU ; Guangyuan LIU ; Nannan GAO ; Zhaoliang DING ; Jie YU ; Chuanlu WEI ; Haijing LI ; Hua WANG ; Shishan DONG ; Jianbao DONG
Chinese Journal of Veterinary Science 2025;45(11):2365-2371
Strangles,caused by Streptococcus equi subsp.equi,remains one of the most prevalent and high-incidence infectious diseases in intensive donkey farms,posing a significant threat to the healthy development of the donkey industry.Vaccination serves as an effective measure for the pre-vention and control of the disease,however,there is currently no attenuated vaccine against this disease in China.To provide a candidate strain for the development of a live attenuated strangles vaccine,this study focused on a wild-type S.equi subsp.equi strain isolated from donkeys.Using homologous recombination gene knockout technology,the aroA gene(encoding 5-enolpyru-vylshikimate-3-phosphate synthase)and the sag A gene(encoding the precursor of streptolysin S toxin)were sequentially deleted to construct a double-gene-deletion strain(ΔsagA/aroA).The virulence and key biological characteristics of the mutant strain were systematically evaluated.TheΔsagA/aroA strain was successfully generated,exhibiting complete loss of hemolytic activity and maintaining stable genetic inheritance over 60 consecutive passages.Electron microscopy revealed that the mutant retained morphological characteristics compared to the wild-type strain,and its growth rate was significantly slower(P<0.000 1).Virulence assessment using a challenge dose of 1× 105 CFU/0.2 mL(the minimum fully lethal dose of the wild-type strain)demonstrated markedly attenuated virulence in the mutant.Immunization trials with 1 ×104 CFU/0.2 mL of theΔsagA/aroA strain revealed a increase in ELISA antibody titers by day 7 post-vaccination,and higher levels at days 14 and 21.Notably,antibody levels in the experimental group were significant-ly higher than those in the control group(P<0.000 1).These findings confirm that the double-gene-deletion strain S.equi subsp.equi ΔsagA/aroA exhibits reduced virulence while retaining im-munogenicity,which suggested it can be used as a promising candidate strain for further develop-ment of a live attenuated strangles vaccine.
10.Ac-SDKP antagonizes lung fibrosis through EGFR/STAT3 pathway in silicosis rats
Wenli LI ; Lu LIU ; Yi HE ; Nana YAO ; Haijing DENG ; Ye QIAN
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(10):721-727
Objective:To examine the regulatory effects of a potential antifibrotic tetrapeptide called N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) on the expression of epidermal growth factor (EGFR) and signal transducer and activator of transcription 3 (STAT3) in lung tissues with fibrosis induced by silicosis in rats. This study aims to explore the potential therapeutic benefits of Ac-SDKP in the prevention and treatment of fibrotic lung diseases associated with silicosis.Methods:In January 2024, disease targets and Ac-SDKP active ingredients were predicted through GeneCards (https://www.genecards.org) and OMIM (https://www.omim.org) databases. Using R 4.2.1 software, we identified overlapping targets between pulmonary fibrosis and AC-SDKP. Cytoscape 3.10.2 was employed to visualize interactions between active chemical components and these targets, followed by GO enrichment analysis and KEGG pathway analysis using R 4.2.1. Forty healthy adult Wistar rats were selected to establish silicosis models through single-dose gavage with 50 mg/ml silica suspension (1. 0 ml per rat). The rats were randomly divided into four groups: model control group (4 weeks), silicosis model group (4 weeks), Ac-SDKP preventive treatment group (acquired via intraperitoneal injection of a micro-release pump containing Ac-SDKP [800 μg/ (kg·d) ] during modeling, maintained for 4 weeks), and Ac-SDKP anti-fibrosis treatment group (acquired via intraperitoneal injection of the same pump after 2 weeks of modeling, continued maintenance for 2 weeks). Each group contained 10 rats. The pathological changes in rat lung tissues were observed. Western blot technology was used to detect the protein expression levels of α-smooth muscle actin (α-SMA), epidermal growth factor receptor (EGFR), signal transduction and activation transcription factor 3 (STAT 3), caspase 3, and caspase 8 in lung tissues. Immunohistochemical techniques were employed to assess the expressions of EGFR, STAT3, caspase 3, and caspase 8. Overall differences between groups were compared using one-way ANOVA.Results:Compared with the control group in the silicosis model, rats in the 4-week group exhibited significant fibrotic nodules. The lung tissues of these rats showed statistically significant increases in α-SMA, EGFR, STAT 3, Caspase 3, and Caspase 8 protein expression ( P<0.05). In contrast, the Ac-SDKP prevention and anti-fibrosis treatment group demonstrated markedly reduced expression levels of these proteins compared to the 4-week silicosis model group, with statistically significant differences ( P<0.05). Immunohistochemical staining revealed that brownish-yellow expression of EGFR, STAT3, Caspase3, and Caspase8 was significantly enhanced in silicotic nodules within the silicosis model group. Conversely, this brownish-yellow expression was notably decreased in the Ac-SDKP prevention and anti-fibrosis treatment group compared to the 4-week silicosis model group. Conclusion:Ac-SDKP may exert antifibrotic effects on the lungs of rats with silicosis by regulating the EGFR/STAT3 pathway.

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