Objective To investigate the development, role, and regulatory mechanism of macrophage efferocytosis in the liver of hosts infected with Schistosoma japonicum. Methods The expression of efferocytosis-related gene like efferocytosis receptors, efferocytosis-related bridging molecules,“eat me” signal and “don’t eat me” signal was detected in the livers of patients and mice infected with S. japonicum in the Gene Expression Omnibus (GEO) database. Ten wild-type (WT) male mice (6 ~ 8 weeks old, weighing 20 ~ 25 g) were randomly divided into a Schistosoma japonicum infection (SJ) group and a normal control (NC) group, with 5 mice in each group. The efferocytosis of neutrophils and T cells by liver macrophages was detected in mice from SJ group and NC group using flow cytometry and immunofluorescence assay, respectively. The expression of efferocytosis-related Mer receptor tyrosine kinase (MerTK) and Axl receptor tyrosine kinase (Axl) proteins was determined in mouse liver tissues using Western blotting assay, and the proportion of MerTK⁺ macrophages and the average fluorescence intensity of macrophage MerTK were detected in mouse livers using flow cytometry. Changes in liver granulomas and fibrosis were observed in mice infected with S. japonicum following injection of efferocytosis inhibitors, and S. japonicum-infected mice without injection of efferocytosis inhibitors served as controls. Bone marrow-derived macrophages (BMDMs) were isolated from macrophage scavenger receptor class A (SR-A) conditional knockout (CKO) and wild-type (WT) mice, and changes in apoptotic neutrophils were detected in SR-A CKO mouse macrophages in vitro using flow cytometry. Then, BMDMs was divided into the WT mono-culture group, the WT and apoptotic neutrophils co-culture group, the SR-A CKO mono-culture group, and the SR-A CKO and neutrophils co-culture group, and the expression of MerTK and Axl was quantified in vitro using Western blotting and real-time quantitative PCR (RT-qPCR) assays during neutrophil efferocytosis. The efferocytosis of neutrophils and T cells by mouse liver macrophages was detected in the SR-A CKO SJ group and the WT SJ group using flow cytometry and immunofluorescence assay, and the expression of MerTK and Axl proteins was determined in mouse liver tissues in both groups using Western blotting. In addition, the proportion of MerTK⁺ macrophages and the average fluorescence intensity of macrophage MerTK were detected in mouse livers in both groups using flow cytometry. Results Data from the GEO database showed that the expression of some efferocytosis receptors and efferocytosis-related bridging molecules, and “eat me” and “don’t eat me” signals all appeared a tendency towards a rise in livers of patients and mice in the SJ group relative to the NC group, suggesting that S. japonicum infection-induced liver diseases may be associated with efferocytosis. Flow cytometry detected higher proportions of Ly6G⁺ cells [(13.13 ± 0.45)% vs. (6.48 ± 0.25)%; t = 22.30, P < 0.05] and CD3⁺ cells [(7.60 ± 0.33)% vs. (3.30 ± 0.42)%; t = 13.98, P < 0.05] in mouse liver macrophages in the SJ group than in the NJ group, and the expression of MerTK protein [(2.30 ± 0.14) vs. (1.14 ± 0.46); t = 4.19, P < 0.05], the mean fluorescence intensity of macrophages [(160.67 ± 15.28) vs. (94.50 ± 19.61); t = 4.81, P < 0.05], and the proportion of MerTK⁺ macrophages [(20.78 ± 4.17)% vs. (6.85 ± 0.39)%; t = 6.57, P < 0.05] were significantly higher in mouse liver tissues in the SJ group than in the NC group. The Axl expression was lower in mouse liver tissues in the SJ group than in the NC group [(1.25 ± 0.08) vs. (1.93 ± 0.37); t = 2.79, P < 0.05], and the area of granulomas around single eggs [(9.18 ± 1.81) × 10⁴μm² vs. (5.24 ± 1.35) × 10⁴ μm²; t = 3.03, P < 0.05] and proportion of collagen fibers [(25.27 ± 3.99)% vs. (15.14 ± 4.02)%; t = 3.10, P < 0.05] were significantly greater in livers of S. japonicum-infected mice with injection of efferocytosis inhibitors than in mice without injection of efferocytosis inhibitors. The in vitro efferocytosis efficiency of BMDMs [(32.83 ± 3.17)% vs. (45.43 ± 2.34)%; t = 5.54, P < 0.05], and the proportions of Ly6G⁺ [(9.37 ± 0.48)% vs. (13.13 ± 0.72)%; t = 7.50, P < 0.05] and CD3⁺ cells [(4.95 ± 0.17)% vs. (7.64 ± 0.50)%; t = 8.87, P < 0.05] in liver macrophages post-infection with S. japonicum were significantly lower in SR-A CKO mice than in WT mice, and the expression of MerTK protein [(0.65 ± 0.25) vs. (1.96 ± 0.69); t = 3.10, P < 0.05], the average fluorescence intensity of macrophages [(138.33 ± 8.39) vs. (160.67 ± 15.28); t = 3.03, P < 0.05] and the proportion of MerTK⁺ macrophages [(13.17 ± 5.01)% vs. (22.63 ± 2.06)%; t = 3.56, P < 0.05] were significantly lower in mouse liver tissues in the SR-A CKO SJ group than in the WT group. Western blotting detected no significant difference in the Axl protein expression in mouse liver tissues between the SR-A CKO SJ group and the WT SJ group [(0.48 ± 0.07) vs. (0.68 ± 0.30); t = 1.09, P > 0.05]. There were significant differences in the relative MerTK mRNA and protein expression during efferocytosis of BMDMs among the WT monoculture group, the WT and apoptotic neutrophils co-culture group, the SR-A CKO mono-culture group, and the SR-A CKO and neutrophils co-culture group (F = 9.41 and 40.68, both P values < 0.05). In addition, there was a significant difference in the relative Axl mRNA expression during efferocytosis of BMDMs among the four groups (F = 13.62, P < 0.05); however, no significant difference was seen in the relative Axl protein expression (F = 1.27, P > 0.05). Conclusions Efferocytosis of liver macrophages is seen in mice infected with S. japonicum and inhibits liver fibrosis. SR-A may up-regulate the efficiency of macrophage efferocytosis through regulating the expression of efferocytosis receptors.

Objective:To investigate the effect of verbascoside(VERB)on high-fat diet-induced atherosclerosis(AS)in ApoE-/-mice and the effect on high mobility histone 1(HMGB1)/receptor for glycation end products(RAGE)/nuclear factor κB(NF-κB)pathway.Methods:A total of 90 ApoE-/-mice were randomly divided into normal group,AS group,VERB group,simvastatin group and VERB+pathway activator HMGB1 group,with 18 mice per group.After 8 weeks of group administration,blood and aorta samples were taken.Fasting serum triacylglycerol(TG),total cholesterol(TC)and low density lipoprotein(LDL)levels were deter-mined by automatic biochemical analyzer.Oil red O,HE and TUNEL staining were performed to observe apoptosis of aortic plaque and endothelial cell(EC).Flow cytometry was performed to analyze circulating EC numbers.Immunohistochemistry was performed to analyze the infiltration area of macrophages(CD68+)and T lymphocytes(CD3+)in aortic plaques.Western blot was performed to detect expressions of HMGB1/RAGE/NF-κB pathway,inflammation and adhesion molecules.Results:Compared with normal group,AS group had lipid plaques in arterial intima,thickness of the media was uneven,TG,TC,LDL levels,lession proportion,plaque area,circulating EC number,arterial EC apoptosis rate,macrophage(CD68+)and T lymphocyte(CD3+)infiltration areas,TNF-α,monocyte chemoattractant protein-1(MCP-1),vascular cell adhesion molecule-1(VCAM-1),intercellular adhesion molecule-1(ICAM-1),cytoplasm HMGB1,total HMGB1,total RAGE protein levels and nuclear/total p65 NF-κB levels were increased(P<0.05),while nuclear HMGB1 protein,nuclear/total HMGB1 and cytosolic p65 NF-κB levels were decreased(P<0.05).After VERB or simvastatin intervention,arterial lesions were alleviated,TG,TC,LDL levels,lession proportion,plaque area,circulating EC number,arterial EC apoptosis rate,macrophage(CD68+)and T lymphocyte(CD3+)infiltration areas,TNF-α,MCP-1,VCAM-1,ICAM-1,cytoplasm HMGB1,total HMGB1,RAGE protein levels and nuclear/total p65 NF-κB level were decreased(P<0.05),while nuclear HMGB1 protein,nuclear/total HMGB1 and cytosolic p65 NF-κB levels were increased(P<0.05),and HMGB1 was able to antagonize the protective effect of VERB on AS mice.Conclusion:VERB can inhibit expressions of inflammatory and adhesion fac-tors in arterial plaques in ApoE-/-mice,reduce EC shedding and apoptosis,therefore improve AS symptoms in ApoE-/-mice,and the mechanism may be related to the inhibition of HMGB1/RAGE and NF-κB pathway.

Objective:To investigate the effect of verbascoside(VERB)on high-fat diet-induced atherosclerosis(AS)in ApoE-/-mice and the effect on high mobility histone 1(HMGB1)/receptor for glycation end products(RAGE)/nuclear factor κB(NF-κB)pathway.Methods:A total of 90 ApoE-/-mice were randomly divided into normal group,AS group,VERB group,simvastatin group and VERB+pathway activator HMGB1 group,with 18 mice per group.After 8 weeks of group administration,blood and aorta samples were taken.Fasting serum triacylglycerol(TG),total cholesterol(TC)and low density lipoprotein(LDL)levels were deter-mined by automatic biochemical analyzer.Oil red O,HE and TUNEL staining were performed to observe apoptosis of aortic plaque and endothelial cell(EC).Flow cytometry was performed to analyze circulating EC numbers.Immunohistochemistry was performed to analyze the infiltration area of macrophages(CD68+)and T lymphocytes(CD3+)in aortic plaques.Western blot was performed to detect expressions of HMGB1/RAGE/NF-κB pathway,inflammation and adhesion molecules.Results:Compared with normal group,AS group had lipid plaques in arterial intima,thickness of the media was uneven,TG,TC,LDL levels,lession proportion,plaque area,circulating EC number,arterial EC apoptosis rate,macrophage(CD68+)and T lymphocyte(CD3+)infiltration areas,TNF-α,monocyte chemoattractant protein-1(MCP-1),vascular cell adhesion molecule-1(VCAM-1),intercellular adhesion molecule-1(ICAM-1),cytoplasm HMGB1,total HMGB1,total RAGE protein levels and nuclear/total p65 NF-κB levels were increased(P<0.05),while nuclear HMGB1 protein,nuclear/total HMGB1 and cytosolic p65 NF-κB levels were decreased(P<0.05).After VERB or simvastatin intervention,arterial lesions were alleviated,TG,TC,LDL levels,lession proportion,plaque area,circulating EC number,arterial EC apoptosis rate,macrophage(CD68+)and T lymphocyte(CD3+)infiltration areas,TNF-α,MCP-1,VCAM-1,ICAM-1,cytoplasm HMGB1,total HMGB1,RAGE protein levels and nuclear/total p65 NF-κB level were decreased(P<0.05),while nuclear HMGB1 protein,nuclear/total HMGB1 and cytosolic p65 NF-κB levels were increased(P<0.05),and HMGB1 was able to antagonize the protective effect of VERB on AS mice.Conclusion:VERB can inhibit expressions of inflammatory and adhesion fac-tors in arterial plaques in ApoE-/-mice,reduce EC shedding and apoptosis,therefore improve AS symptoms in ApoE-/-mice,and the mechanism may be related to the inhibition of HMGB1/RAGE and NF-κB pathway.

Objective To develop a novel electric stapler, so as to improve the automation, convenience and precision of minimally invasive surgery. Methods The clamping, firing and turning mechanism of the new electric stapler was innovatively designed to realize the electric drive of minimally invasive surgical anastomosis on the basis of traditional mechanical stapler. The motion process of electric clamping, firing and double-screw turning mechanism was analyzed in detail, and the equations for motion function of three mechanisms were solved, providing a theoretical basis for the intelligent control algorithm of electric stapler. Results The electric clamping and firing process was simulated using ADAMS software to verify the equation of motion. The prototype of the new electric stapler was made, and the anastomosis experiment and blasting pressure experiment of the in vitro small intestine tissues were carried out. The range of anastomotic blasting pressure was between 3.7 kPa and 11.67 kPa, meeting the basic requirements in clinic. Conclusions The structure of the new electric stapler can meet the requirements of electric pressing and firing in minimally invasive surgery, contributing to achieve tissue anastomosis more conveniently, quickly and effectively.