Celastrol induces ferroptosis in activated HSCs to ameliorate hepatic fibrosis via targeting peroxiredoxins and HO-1

Ferroptosis is a form of regulated cell death, characterized by excessive membrane lipid peroxidation in an iron- and ROS-dependent manner. Celastrol, a natural bioactive triterpenoid extracted from Tripterygium wilfordii, shows effective anti-fibrotic and anti-inflammatory activities in multiple hepatic diseases. However, the exact molecular mechanisms of action and the direct protein targets of celastrol in the treatment of liver fibrosis remain largely elusive. Here, we discover that celastrol exerts anti-fibrotic effects via promoting the production of reactive oxygen species (ROS) and inducing ferroptosis in activated hepatic stellate cells (HSCs). By using activity-based protein profiling (ABPP) in combination with bio-orthogonal click chemistry reaction and cellular thermal shift assay (CETSA), we show that celastrol directly binds to peroxiredoxins (PRDXs), including PRDX1, PRDX2, PRDX4 and PRDX6, through the active cysteine sites, and inhibits their anti-oxidant activities. Celastrol also targets to heme oxygenase 1 (HO-1) and upregulates its expression in activated-HSCs. Knockdown of PRDX1, PRDX2, PRDX4, PRDX6 or HO-1 in HSCs, to varying extent, elevated cellular ROS levels and induced ferroptosis. Taken together, our findings reveal the direct protein targets and molecular mechanisms via which celastrol ameliorates hepatic fibrosis, thus supporting the further development of celastrol as a promising therapeutic agent for liver fibrosis.

Morphological analysis of proximal tibial epiphyseal fusion site in normal adults / 中华骨科杂志

Objective:To study the morphologic features of the fusion site of proximal tibial epiphysis in normal adults and analyze its potential clinical value based on Mimics three-dimensional (3D) reconstruction.Methods:CT images of knee joint of 68 patients without obvious abnormalities of lower limbs were retrospectively analyzed in electronic database of our hospital from June 2020 to June 2021, including 41 males and 27 females. The mean age of the patients was 38.7±8.4 years (range, 25-55 years), and the mean body mass index (BMI) was 25.3±4.0 kg/m 2 (range, 18.75-41.8 kg/m 2). Mimics 3D reconstruction technique was used to reconstruct the 3D model of the proximal tibia and epiphyseal fusion site. The relationship between the surface area of epiphyseal fusion site and age and BMI was studied, and the changes of cortical thickness and density at epiphyseal fusion site were also explored. Results:The fusion site of adult epiphyseal reconstructed by Mimics 3D reconstruction is a complex wavy surface structure in 3D space. The surface area of the epiphyseal fusion site was 2,994.7±645.3 mm 2 (range, 1,704.0-4,650.0 mm 2) obtained by 3-Matic Research 12.0. The fusing area of male epiphysis was 3 269.3±533.9 mm 2 than that of female 2,577.6±578.7 mm 2, the difference was statistically significant ( t=5.06, P<0.001). However, there was no significant correlation between the epiphyseal fusion site surface area and age ( R2=0.02, P=0.268) and BMI ( R2=0.04, P=0.125). Mimics software was used to obtain the CT values of bone cortex at the epiphysis line and the distal end of the epiphysis line at 10 mm and 20 mm levels as 451.059±74.953 Hu, 1,018.412±125.732 Hu and 1,414.162±107.848 Hu, respectively. The thickness of bone cortex was 1.814±0.090 mm, 2.511±0.089 mm and 3.189±0.185 mm at 10 mm and 20 mm layers of epiphysis line and distal epiphysis line, respectively. Conclusion:In this study, Mimics 3D reconstruction technique was used to visualize the fusion site of the proximal tibial epiphysis in normal adults. The epiphyseal fusion site of adult is a undulating plate-like structure, and the cortical bone density of epiphyseal fusion site is low and thin, theoretically, it is easy to fracture under indirect violence.

Detection and analysis of neutralizing antibodies against SARS-CoV-2 in convalescent plasma donors / 中国输血杂志

【Objective】 To detect the anti-SARS-CoV-2 neutralizing antibody levels in convalescent plasma (CP) and to evaluate whether it has specific anti-SARS-CoV-2 S antigen effect, so as to provide laboratory data support for clinical use of CP. 【Methods】 Nine CP donors who have recovered from COVID-19 were studied, and 4 volunteers who completed the vaccination and 3 asymptomatic infected blood donors were compared. Anti-SARS-CoV-2 antibodies including total antibody, IgM and IgG were measured by chemiluminescence microparticle immunoassays (CMIA) test in three groups. The VSV pseudovirus-based neutralization assay for evaluating neutralizing antibodies against SARS-CoV-2 was carried out in all samples. 【Results】 All samples were tested positive by the total antibody and IgG CMIA in COVID-19 CP donors and recipients of inactivated COVID-19 vaccine. High titers of IgG were observed in CP donors and vaccine recipients compared with asymptomatic blood donors. All vaccine recipients and 8 of 9 CP donors tested positive by SARS-CoV-2 pseudovirus-based neutralization test, whereas all asymptomatic blood donors tested negative. 【Conclusion】 The levels and characteristics of neutralizing antibodies among COVID-19 CP donors, vaccine recipients and asymptomatic blood donors were different. When unable to implement the pseudovirus assay to measure neutralizing antibodies, the detection of total antibody can be considered instead.

Treatment of intra-articular distal femur fracture by our slot-designed compression bolt combined with bilateral locking compression plates: a biomechanical analysis / 中华创伤骨科杂志

Objective:To evaluate the biomechanical stability of our slot-designed compression bolt (SCB) combined with bilateral locking compression plates (LCPs) in the treatment of intra-articular distal femur fracture.Methods:In 24 adult male knee specimens treated with formalin, the femoral bony part was preserved to establish standard models of intra-articular distal femur fracture (AO type 33-C1). According to the random number table, the fracture models were divided into 2 equal groups: an experimental group ( n=12) subjected to fixation with one SCB combined with bilateral LCPs with 10 locking screws and a control group ( n=12) subjected to fixation with bilateral LCPs with 12 locking screws. In each model, a vertical ballast test was conducted to record the maximum axial displacement of the system and a horizontal torsion test to calculate the torsional stiffness of the system. When the loading pressure was 0-1,000 N in the biomechanical machine, structural abnormalities were observed in the 2 groups of models and the system maximum axial displacement and system torsional stiffness were compared between the 2 groups. Results:When the vertical ballast pressure was 400 N, 600 N, 800 N and 1,000 N, the maximum axial displacement of the system was, respectively, (0.14±0.01) mm, (0.25±0.01) mm, (0.41±0.02) mm and (0.63 ± 0.02) mm in the experimental group, and (0.15 ± 0.01) mm, (0.26 ± 0.01) mm, (0.46 ± 0.03) mm, and (0.67 ± 0.04) mm in the control group. Compared with the control group, the average maximum axial displacement in the experimental group decreased significantly under the axial pressure of 600-1,000 N ( P<0.05). When the horizontal torsion reached 5°, the torsional stiffness was, respectively, (2.00±0.12) Nm/° and (2.02±0.07) Nm/° in the experimental group and the control group, showing no significant difference between the 2 groups ( P>0.05). Conclusions:In the treatment of intra-articular distal femur fracture, compared with simple bilateral LCPs, our SCB combined with bilateral LCPs demonstrate similar torsional stability but better axial biomechanical stability. As our SCB has advantages of bilateral compression and minimal invasion in operation, it may be a new option for the reduction and compression treatment of intra-articular fractures.

A highly efficient protein corona-based proteomic analysis strategy for the discovery of pharmacodynamic biomarkers / 药物分析学报

The composition of serum is extremely complex,which complicates the discovery of new pharmaco-dynamic biomarkers via serum proteome for disease prediction and diagnosis.Recently,nanoparticles have been reported to efficiently reduce the proportion of high-abundance proteins and enrich low-abundance proteins in serum.Here,we synthesized a silica-coated iron oxide nanoparticle and devel-oped a highly efficient and reproducible protein corona(PC)-based proteomic analysis strategy to improve the range of serum proteomic analysis.We identified 1,070 proteins with a median coefficient of variation of 12.56％using PC-based proteomic analysis,which was twice the number of proteins iden-tified by direct digestion.There were also more biological processes enriched with these proteins.We applied this strategy to identify more pharmacodynamic biomarkers on collagen-induced arthritis(CIA)rat model treated with methotrexate(MTX).The bioinformatic results indicated that 485 differentially expressed proteins(DEPs)were found in CIA rats,of which 323 DEPs recovered to near normal levels after treatment with MTX.This strategy can not only help enhance our understanding of the mechanisms of disease and drug action through serum proteomics studies,but also provide more pharmacodynamic biomarkers for disease prediction,diagnosis,and treatment.

Celastrol increases osteosarcoma cells line HOS lysis by γδ T cells through TRAIL way / 中国免疫学杂志

Objective:To investigate whether celastrol can increase the cytotoxic activity of γδ T cells against osteosarcoma (OS) cells line HOS through TRAIL way. Methods:The death receptors 4/5 (DR4/5) protein levels in the OS cell lines HOS was in-vestigated by Western blot analysis. Zoledronate ( ZOL) was used to induceγδT cells from PBMCs of healthy volunteers.γδT cell cy-totoxicity against HOS cells was investigated by a standard lactate dehydrogenase release assay ( LDH ) . Results:Celastrol increased DR4/5 protein expression in HOS ( P<0. 05 ) .γδ T cells from PBMCs of healthy volunteers showed cytotoxicity against HOS ( P<0. 05). Following co-culture with HOS pre-treated with celastrol (1 μmol/L) for 24 h,γδ T cells showed significantly higher cytotoxicity against HOS (P<0. 05). The induction of DR4/5 molecules increased lysis of HOS by γδ T cells which was abolished by addition of a blocking TRAIL antibody. Conclusion:Celastrol can enhance γδ T cells'cytotoxic activity against OS cells line HOS through TRAIL way.