Identification of structural origins of complex charge heterogeneity in therapeutic ACE2Fc fusion protein facilitated by free-flow isoelectric focusing.

Fc Fusion protein represents a versatile molecular platform with considerable potential as protein therapeutics of which the charge heterogeneity should be well characterized according to regulatory guidelines. Angiotensin-converting enzyme 2 Fc fusion protein (ACE2Fc) has been investigated as a potential neutralizing agent to various coronaviruses, including the lingering SARS-CoV-2, as this coronavirus must bind to ACE2 to allow for its entry into host cells. ACE2Fc, an investigational new drug developed by Henlius (Shanghai China), has passed the Phase I clinical trial, but its huge amount of charge isoforms and complicated charge heterogeneity posed a challenge to charge variant investigation in pharmaceutical development. We employed offline free-flow isoelectric focusing (FF-IEF) fractionation, followed by detailed characterization of enriched ACE2Fc fractions, to unveil the structural origins of charge heterogeneity in ACE2Fc expressed by recombinant CHO cells. We adopted a well-tuned 3-component separation medium for ACE2Fc fractionation, the highest allowable voltage to maximize the FF-IEF separation window and a mild Protein A elution method for preservation of protein structural integrity. Through peptide mapping and other characterizations, we revealed that the intricate profiles of ACE2Fc charge heterogeneity are mainly caused by highly sialylated multi-antenna N-glycosylation. In addition, based on fraction characterization and in silico glycoprotein model analysis, we discovered that the large acidic glycans at N36, N73, and N305 of ACE2Fc were able to decrease the binding activity towards Spike (S) protein of SARS-CoV-2. Our study exemplifies the value of FF-IEF in highly complex fusion protein characterization and revealed a quantitative sialylation-activity relationship in ACE2Fc.

Can digital inclusive finance promote agricultural green development?

Digital inclusive finance (DIF) provides new momentum for green agricultural development (AGD). This paper measured AGD with entropy weight TOPSIS in five dimensions, including resource conservation, environmental friendliness, ecological conservation, green supply, and economic growth. After that, it estimated the regional spillover effects and threshold impacts of DIF on AGD utilizing China's provincial panel data from 2011 to 2020. The paper shows that (1) DIF and AGD have such a U-shaped complex interrelationship; (2) the AGD is spatially impacted by DIF. The unique manifestation is that as DIF has increased, its effect on AGD has steadily changed from being direct to being indirect, and this effect has regional heterogeneity; and (3) in regions with higher levels of green technology innovation, better development of traditional finance, or relatively concentrated agricultural industries, DIF plays a more prominent role in promoting the AGD.

Human understandable thyroid ultrasound imaging AI report system - A bridge between AI and clinicians.

Artificial intelligence (AI) enables accurate diagnosis of thyroid cancer; however, the lack of explanation limits its application. In this study, we collected 10,021 ultrasound images from 8,079 patients across four independent institutions to develop and validate a human understandable AI report system named TiNet for thyroid cancer prediction. TiNet can extract thyroid nodule features such as texture, margin, echogenicity, shape, and location using a deep learning method conforming to the clinical diagnosis standard. Moreover, it offers excellent prediction performance (AUC 0.88) and provides quantitative explanations for the predictions. We conducted a reverse cognitive test in which clinicians matched the correct ultrasound images according to TiNet and clinical reports. The results indicated that TiNet reports (87.1% accuracy) were significantly easier to understand than clinical reports (81.6% accuracy; p < 0.001). TiNet can serve as a bridge between AI-based diagnosis and clinicians, enhancing human-AI cooperative medical decision-making.

Automated diagnosis and management of follicular thyroid nodules based on the devised small-dataset interpretable foreground optimization network deep learning: a multicenter diagnostic study.

BACKGROUND: Currently, follicular thyroid carcinoma (FTC) has a relatively low incidence with a lack of effective preoperative diagnostic means. To reduce the need for invasive diagnostic procedures and to address information deficiencies inherent in a small dataset, we utilized interpretable foreground optimization network deep learning to develop a reliable preoperative FTC detection system. METHODS: In this study, a deep learning model (FThyNet) was established using preoperative ultrasound images. Data on patients in the training and internal validation cohort ( n =432) were obtained from Ruijin Hospital, China. Data on patients in the external validation cohort ( n =71) were obtained from four other clinical centers. We evaluated the predictive performance of FThyNet and its ability to generalize across multiple external centers and compared the results yielded with assessments from physicians directly predicting FTC outcomes. In addition, the influence of texture information around the nodule edge on the prediction results was evaluated. RESULTS: FThyNet had a consistently high accuracy in predicting FTC with an area under the receiver operating characteristic curve (AUC) of 89.0% [95% CI 87.0-90.9]. Particularly, the AUC for grossly invasive FTC reached 90.3%, which was significantly higher than that of the radiologists (56.1% [95% CI 51.8-60.3]). The parametric visualization study found that those nodules with blurred edges and relatively distorted surrounding textures were more likely to have FTC. Furthermore, edge texture information played an important role in FTC prediction with an AUC of 68.3% [95% CI 61.5-75.5], and highly invasive malignancies had the highest texture complexity. CONCLUSION: FThyNet could effectively predict FTC, provide explanations consistent with pathological knowledge, and improve clinical understanding of the disease.

Demonstrating analytical similarity of a biosimilar HLX04 to bevacizumab with a panel of state-of-the-art methods and tiering of quality attributes.

Therapeutical monoclonal antibodies are structurally and functionally complex, whereas the innovator's manufacturing processes are proprietary. With respect to the similarity assessment, a proposed biosimilar product needs to demonstrate a side-by-side comparison between the reference product (RP) and candidate product in terms of physicochemical properties and biological activities, as well as nonclinical and clinical outcomes. Here, a comprehensive analytical similarity assessment was performed for in-depth comparison of HLX04, China-sourced Avastin® (CN-Avastin®), and Europe-sourced Avastin® (EU-Avastin®) following a tier-based quality attribute (QA) evaluation. A series of orthogonal and state-of-the-art analytical techniques were developed for the assessment. Ten lots of HLX04 were compared with 29 lots bevacizumab RP. Referred to the characterization results, HLX04 is highly similar to the RPs with respect to physicochemical properties and biological functions. In addition, HLX04 was found with similar stability and degradation behaviors upon multiple stressed conditions to bevacizumab. Minor differences were observed in glycosylation, aggregates, FcγRIIIa(F), and FcγRIIIa(V) binding activities; nevertheless, they were evaluated and demonstrated not to impact clinical outcomes. According to the reported clinical results, the totality of evidence, including the pharmacokinetic, efficacy, safety, and immunogenicity, further shows that HLX04 is similar to CN-/EU-Avastin®.

Characterization of Extensively Drug-Resistant Salmonella enterica Serovar Kentucky Sequence Type 198 Isolates from Chicken Meat Products in Xuancheng, China.

The purpose of this study was to characterize extensively drug-resistant Salmonella enterica serovar Kentucky sequence type 198 (ST198) isolates from chicken meat products. Ten S. Kentucky strains obtained from chicken meat products in Xuancheng, China, carried 12 to 17 resistance genes, such as blaCTX-M-55, rmtB, tet(A), floR, and fosA3, combined with mutations within gyrA (S83F and D87N) and parC (S80I), resulting in resistance to numerous antimicrobial agents, including the clinically important antibiotics cephalosporin, ciprofloxacin, tigecycline, and fosfomycin. These S. Kentucky isolates shared a close phylogenetic relationship (21 to 36 single-nucleotide polymorphisms [SNPs]) and showed close genetic relatedness to two human clinical isolates from China. Three S. Kentucky strains were subjected to whole-genome sequencing using Pacific Biosciences (PacBio) single-molecule real-time (SMRT) technology. All antimicrobial resistance genes were located on their chromosomes and clustered in one multiresistance region (MRR) and Salmonella genomic island (SGI) SGI1-K. The MRRs in three S. Kentucky strains were bounded by IS26 at both ends and were inserted downstream of the bcfABCDEFG cluster with 8-bp direct repeats. The MRRs were related to those of IncHI2 plasmids but differed by insertions, deletions, and rearrangements of multiple segments involving resistance genes and plasmid backbones. This finding suggests that the MRR fragment possibly originates from IncHI2 plasmids. Four SGI1-K variants with slight differences were identified in 10 S. Kentucky strains. Mobile elements, particularly IS26, play an essential role in forming distinct MRRs and SGI1-K structures. In conclusion, the emergence of extensively drug-resistant S. Kentucky ST198 strains containing numerous chromosomally located resistance genes is alarming and needs continued surveillance. IMPORTANCE Salmonella spp. are important foodborne pathogens, and multidrug-resistant (MDR) Salmonella strains have become a serious threat to clinical therapy. MDR S. Kentucky ST198 strains have been increasingly reported from various sources and have become a global risk. In this study, we described extensively drug-resistant S. Kentucky ST198 strains from chicken meat products from a city in China. Numerous resistance genes are clustered in the chromosomes of S. Kentucky ST198 strains, possibly acquired with the help of mobile elements. This would facilitate the spread of numerous resistance genes as intrinsic chromosomal genes within this global epidemic clone, with the potential to capture more resistance genes. The emergence and dissemination of extensively drug-resistant S. Kentucky ST198 pose a severe clinical and public health threat; therefore, continuous surveillance is warranted.

Controlled Release of TGF-ß3 for Effective Local Endogenous Repair in IDD Using Rat Model.

Introduction: Intervertebral disc (IVD) degeneration (IDD) is one of the most widespread musculoskeletal diseases worldwide and remains an intractable clinical challenge. Currently, regenerative strategies based on biomaterials and biological factors to facilitate IVD repair have been widely explored. However, the harsh microenvironment, such as increased ROS and acidity, of the degenerative region impedes the efficiency of IVD repair. Here, an intelligent biodegradable nanoplatform using hollow manganese dioxide (H-MnO2) was developed to modulate the degenerative microenvironment and release transforming growth factor beta-3 (TGF-ß3), which may achieve good long-term therapeutic effects on needle puncture-induced IDD. Methods: Surface morphology and elemental analysis of the MnO2 nanoparticles (NPs) were performed by transmission electron microscopy and an energy-dispersive X-ray spectroscopy detector system, respectively. The biological effects of MnO2 loaded with TGF-ß3 (TGF-ß3/MnO2) on nucleus pulposus cells (NPCs) were assessed via cytoskeleton staining, EdU staining, qPCR and immunofluorescence. The efficacy of TGF-ß3/MnO2 on needle puncture-induced IDD was further examined using MRI and histopathological and immunohistochemical staining. Results: The MnO2 NPs had a spherical morphology and hollow structure that dissociated in the setting of a low pH and H2O2 to release loaded TGF-ß3 molecules. In the oxidative stress environment, TGF-ß3/MnO2 was superior to TGF-ß3 and MnO2 NPs in the suppression of H2O2-induced matrix degradation, ROS, and apoptosis in NPCs. When injected into the IVDs of a rat IDD model, TGF-ß3/MnO2 was able to prevent the degeneration and promote self-regeneration. Conclusion: Use of an MnO2 nanoplatform for biological factors release to regulate the IDD microenvironment and promote endogenous repair may be an effective approach for treating IDD.

Chromosomally Located fosA7 in Salmonella Isolates From China.

This study aimed to investigate the prevalence of fosfomycin fosA7 in Salmonella enterica isolates from food animals and retail meat products in China and the impact of fosA7 on bacterial fitness. A total of 360 Salmonella isolates collected from 11 provinces and cities in China were detected for fosA7. All fosA7-positive Salmonella isolates were determined minimum inhibitory concentrations (MICs) and sequenced by Illumina Hiseq. The fosA7 gene of S. Derby isolate HA2-WA5 was knocked out. The full length of fosA7 was cloned into vector pBR322 and then transformed into various hosts. MICs of fosfomycin, growth curves, stability, and fitness of fosA7 were evaluated. The fosA7 gene was identified in S. Derby (ST40, n = 30) and S. Reading (ST1628, n = 5). MICs to fosfomycin of 35 fosA7-positive isolates were 1 to 32 mg/L. All fosA7 were located on chromosomes of Salmonella. The deletion of fosA7 in HA2-WA5 decreased fosfomycin MIC by 16-fold and slightly affected its fitness. The acquisition of plasmid-borne fosA7 enhanced MICs of fosfomycin in Salmonella (1,024-fold) and Escherichia coli (16-fold). The recombinant plasmid pBR322-fosA7 was stable in Salmonella Typhimurium, S. Pullorum, S. Derby, and E. coli, except for Salmonella Enteritidis, and barely affected on the growth of them but significantly increased biological fitness in Salmonella. The spread of specific Salmonella serovars such as S. Derby ST40 will facilitate the dissemination of fosA7. fosA7 can confer high-level fosfomycin resistance and enhance bacterial fitness in Salmonella if transferred on plasmids; thus, it has the potential to be a reservoir of the mobilized fosfomycin resistance gene.

Coexistence of bla OXA-58 and tet(X) on a Novel Plasmid in Acinetobacter sp. From Pig in Shanghai, China.

The purpose of this study was to characterize the complete sequence of a novel plasmid carrying tigecycline resistance gene tet(X) and carbapenemase gene bla OXA-58 from a swine Acinetobacter sp. strain SH19PTT10. Minimal inhibitory concentration (MIC) was performed using microbroth dilution method. The isolate SH19PTT10 was highly resistant (16 mg/L) to tigecycline, and also exhibited resistance to ampicillin, streptomycin, tetracycline, chloramphenicol, florfenicol, ciprofloxacin, and sulfamethoxazole/trimethoprim. Although SH19PTT10 harbored bla OXA-58, it was susceptible to cefotaxime and meropenem. The genome sequence of SH19PTT10 was determined using PacBio single-molecule real-time sequencing. Plasmid pYUSHP10-1 had a size of 174,032 bp and showed partial homology to several plasmids found in Acinetobacter isolates. It contained two repA genes, putative toxin-antitoxin systems (HipA/HipB, RelE/RelB, and BrnT/BrnA), partitioning genes (parA and parB), and heavy metal resistance-associated genes (copA/copB, nrp, and czcA/czcD) but the transfer region or proteins was not found. pYUSHP10-1 carried 16 resistance genes, mainly clustered in two mosaic multiresistance regions (MRRs). The first MRR contained sul3, qacI-aadA1-clmA1-aadA2-blaCARB-2-dfrA16 cassette, aac(3)-IId, and bla OXA-58. The bla OXA-58 gene was associated with ISAba3, as previously described. The second MRR is the tet(X) region (ISAcsp12-aph(3')-Ia-IS26-ΔxerD-tet(X)-res-ISCR2-sul2) related to the corresponding region in other tet(X)-bearing plasmids. The pdif sites, as well as mobile elements, play an important role in mobilization of DNA modules and plasmid evolution. Coexistence of numerous resistance genes on a single plasmid may contribute to the dissemination of these genes under pressure posed by different agents, which may explain the presence of clinically crucial resistance genes tet(X) and bla OXA-58 in livestock. Thus, rational drug use and continued surveillance of tet(X) and bla OXA-58 in livestock are warranted.

Mesenchymal stem cells-derived exosomes ameliorate nucleus pulposus cells apoptosis via delivering miR-142-3p: therapeutic potential for intervertebral disc degenerative diseases.

Intervertebral disc degeneration (IDD) is the main cause of lower back pain (LBP), and puzzles massive individuals worldwide. Mesenchymal stem cells (MSCs) transplantation has been demonstrated to potentially ameliorate IDD progression, while the underlying mechanism has not been fully explained. Interleukin-1ß (IL-1ß) was used to induce nucleus pulposus cells (NPCs) injury. Bone marrow MSCs-derived exosomes were isolated using the super centrifugation method, and characterized using Transmission electron microscopy (TEM) and western blot. Cell viability was determined by MTT, while apoptosis was measured by Annexin-V staining using flow cytometry. miR-142-3fp and gene expressions were measured by real-time PCR. The protein expressions were determined by western blot. Herein, we found exosomes from bone marrow MSCs are circular vesicles, about 80 nm in diameter, and with robust expression of TSG101 and CD63, but without of Calnexin. MSCs exosomes alleviated NPCs apoptosis by reducing IL-1ß-induced inflammatory cytokines secretion and MAPK signaling activation. Additionally, MSCs exosomes inhibited NPCs apoptosis and MAPK signaling by delivering miR-142-3p that targets mixed lineage kinase 3 (MLK3). Overexpression of MLK3 abolished the effects of MSCs exosomes on the inflammatory condition, cell apoptosis, and MAPK signaling activation in NPCs. The results confirmed that bone marrow MSCs-derived exosomes-packaged miR-142-3p alleviates NPCs injury through suppressing MAPK signaling by targeting MLK3. The work highlights the therapeutic effect of MSCs on IDD progression, and bone marrow MSCs exosomes might be apromising therapeutic strategy for IDD.

Circular RNA CDR1as Exerts Oncogenic Properties Partially through Regulating MicroRNA 641 in Cholangiocarcinoma.

It has been found that the circular RNA (circRNA) CDR1as is upregulated in cholangiocarcinoma (CCA) tissues. In this study, we tried to explore the roles of CDR1as in CCA. CDR1as was overexpressed or knocked down in human CCA cells to assess the effects of CDR1as on cell behaviors and tumor xenograft growth. In vitro, the CDR1as level was significantly increased in CCA cell lines. The results showed that CDR1as promoted the cell proliferation, migration, invasion, and activation of the AKT3/mTOR pathway in CCA cells. Moreover, miR-641, a predicted target microRNA (miRNA) of CDR1as, could partially reverse the effects of CDR1as on cell behaviors in CCA cells. Furthermore, CDR1as improved tumor xenograft growth, and it could be attenuated by miR-641 in vivo Additionally, CDR1as expression was inversely correlated with miR-641 in CCA cells, and miR-641 could directly bind with CDR1as and its target genes, the AKT3 and mTOR genes. Mechanistically, CDR1as could bind with miR-641 and accelerate miR-641 degradation, which possibly leads to the upregulation of the relative mRNA levels of AKT3 and mTOR in RBE cells. In conclusion, our findings indicated that CDR1as might exert oncogenic properties, at least partially, by regulating miR-641 in CCA. CDR1as and miR-641 could be considered therapeutic targets for CCA.

Demonstrating Analytical Similarity of Trastuzumab Biosimilar HLX02 to Herceptin® with a Panel of Sensitive and Orthogonal Methods Including a Novel FcγRIIIa Affinity Chromatography Technology.

BACKGROUND: A biosimilar needs to demonstrate its similarity to the originator reference product (RP) in terms of structural and functional properties as well as nonclinical and clinical outcomes. OBJECTIVES: The aim was to assess the analytical similarity between the trastuzumab biosimilar HLX02 and Europe-sourced Herceptin® (EU-Herceptin®) and China-sourced Herceptin® (CN-Herceptin®) following a quality-by-design (QbD) quality study and tier-based quality attribute evaluation. METHODS: A panel of highly sensitive and orthogonal methods, including a novel Fc gamma receptor IIIa (FcγRIIIa) affinity chromatography technique that enables quantitative comparison of glycan effects on effector function, was developed for the assessment. To ensure the full product variability was captured, ten batches of HLX02 were compared with 39 RP batches with expiry dates from August 2017 to March 2021. RESULTS: The extensive three-way similarity assessment demonstrated that HLX02 is highly similar to the RPs. Furthermore, the %afucose, %galactose, and FcγRIIIa affinity of the RPs were observed to first decrease and then return to the original level in relation to their expiry dates, and the RP batches can be subgrouped by their FcγRIIIa affinity chromatograms. HLX02 is demonstrated to be more similar to the RPs of the high FcγRIIIa affinity group. CONCLUSION: Besides having an overall high analytical similarity to both EU-Herceptin® and CN-Herceptin®, HLX02 is more similar to Herceptin® with high FcγRIIIa affinity, a result that demonstrates the power of the novel FcγRIIIa affinity chromatography technology in biosimilarity evaluation.

Emergence of 16S rRNA Methylase Gene rmtB in Salmonella Enterica Serovar London and Evolution of RmtB-Producing Plasmid Mediated by IS26.

This study aimed to characterize 16S rRNA methylase genes among Salmonella and to elucidate the structure and evolution of rmtB-carrying plasmids. One hundred fifty-eight Salmonella isolates from one pig slaughterhouse were detected as containing 16S rRNA methylase genes; two (1.27%) Salmonella London isolates from slaughtered pigs were identified to carry rmtB. They were resistant to gentamicin, amikacin, streptomycin, ampicillin, tetracycline, florfenicol, ciprofloxacin, and sulfamethoxazole/trimethoprim. The complete sequences of RmtB-producing isolates were obtained by PacBio single-molecule real-time sequencing. The isolate HA1-SP5 harbored plasmids pYUHAP5-1 and pYUHAP5-2. pYUHAP5-1 belonged to the IncFIBK plasmid and showed high similarity to multiple IncFIBK plasmids from Salmonella London in China. The rmtB-carrying plasmid pYUHAP5-2 contained a typical IncN-type backbone; the variable region comprising several resistance genes and an IncX1 plasmid segment was inserted in the resolvase gene resP and bounded by IS26. The sole plasmid in HA3-IN1 designated as pYUHAP1 was a cointegrate of plasmids from pYUHAP5-1-like and pYUHAP5-2-like, possibly mediated by IS26 via homologous recombination or conservative transposition. The structure differences between pYUHAP1 and its corresponding part of pYUHAP5-1 and pYUHAP5-2 may result from insertion, deletion, or recombination events mediated by mobile elements (IS26, ISCR1, and ISKpn43). This is the first report of rmtB in Salmonella London. IncN plasmids are efficient vectors for rmtB distribution and are capable of evolving by reorganization and cointegration. Our results further highlight the important role of mobile elements, particularly IS26, in the dissemination of resistance genes and plasmid evolution.

Effects of medial support screws on locking plating of proximal humerus fractures in elderly patients: a retrospective study.

BACKGROUND: This study aimed to explore the effects of medial support screws (MSS) on the locking proximal humeral plate in elderly patients who suffered from proximal humeral fractures. METHODS: From December 2016 to December 2018, eighty-five elderly patients who suffered from proximal humeral fracture and received standard plate or locking plate with or without MSS were selected. The patients were allocated into 3 groups: Standard plate group (n=23), Locking plate without MSS group (n=34) and Locking plate with MSS group (n=28). Clinical data from all these 3 groups were collected and analyzed. RESULTS: These eighty-five elder patients (ranging 60-78 years) accomplished a follow-up with an average of 16.3 months. The outcome data showed that significant difference was found on the Constant score, humeral internal rotation angle and humeral height ratio (all the P<0.05) among 3 groups, and a highest Constant score and a lowest humeral internal rotation angle and humeral height ratio loss was revealed in Locking platelet with MSS group. Furthermore, the lowest incidence of post-operation complication events (7.1%, P=0.051) and an evident reduction of secondary surgery incidence (P=0.021) was also presented in Locking plate with MSS among these 3 groups. CONCLUSIONS: The medial support screws in the locking proximal humeral plate in treating proximal humeral fractures could reduce humerus restoration loss and humeral internal rotation angle.

Evanescent resonant mode for a T-shaped cavity in a terahertz parallel-plate waveguide.

The evanescent resonant modes are proposed for a T-shaped cavity in a terahertz (THz) parallel-plate waveguide (PPWG) to understand the essence of the resonant phenomenon. The theoretical modal field and the resonant frequency of the TE2-like evanescent resonant mode show agreement with the simulated ones through the whole THz region. The modal field consists of three evanescent fields outside the cross region and one propagation field inside the cross region. When the TE2-like mode is excited, the input THz wave is reflected. The resonance frequency of the TE2-like mode depends closely on the geometrical parameters of the T-shaped cavity. In particular, the separation of the PPWG must be twice larger than the width of the groove to avoid the non-evanescent electric field in the groove. In addition, the electric field of the TE1-like mode is localized in the T-shaped cavity. These results have potential applications in field enhancement, sensors, and filters.

[The role and mechanism of S100 calcium binding protein B in osteoarthritis cartilage damage repair].

Objective: To investigate the role and mechanism of S100 calcium binding protein B (S100B) in osteoarthritis (OA) cartilage damage repair. Methods: Twenty New Zealand rabbits were randomly divided into control group and model group, with 10 rabbits in each group. Rabbits in the model group were injured by the right knee joint immobilization method to make the artilage injury model, while the control group did not deal with any injury. After 4 weeks, the levels of interleukin-1ß (IL-1ß) and tumor necrosis factor α (TNF-α) in synovial fluid were detected by ELISA method; the mRNA and protein expressions of S100B, fibroblast growth factor 2 (FGF-2), and FGF receptor 1 (FGFR1) in cartilage tissue were examined by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot assay. Human synovial fibroblasts (SF) were isolated and cultured in vitro. The effects of S100B overexpression and knockdown on the levels of IL-1ß and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed. Moreover, the effects of FGFR1 knockdown in above S100 overexpression system on the levels of IL-1ß and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed. Results: ELISA detection showed that the expressions of IL-1ß and TNF-α in the synovial fluid of the model group were significantly higher than those of the control group ( P<0.05); qRT-PCR and Western blot detection showed that the mRNA and protein expressions of S100B, FGF-2, and FGFR1 in cartilage tissue were significantly higher than those of the control group ( P<0.05). Overexpression and knockdown S100 could respectively significantly increase and decrease lipopolysaccharides (LPS) induced IL-1ß and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 ( P<0.05); whereas FGFR1 knockdown could significantly decrease LPS induced IL-1ß and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 ( P<0.05). Conclusion: S100B protein can regulate the inflammatory response of SF and may affect the repair of cartilage damage in OA, and the mechanism may be related to the activation of FGF-2/FGFR1 signaling pathway.

S100B regulates inflammatory response during osteoarthritis via fibroblast growth factor receptor 1 signaling.

The present study aimed to investigate the role of S100B in the inflammation process during osteoarthritis (OA). OA cartilage samples were collected for S100B expression analysis. S100B expression levels were significantly increased in patients with OA compared with the Controls (1.28±0.66 vs. 0.42±0.31; P=0.01) and were determined to be correlated with TNF­α (r=0.42; P=0.04) and IL­1ß (r=0.73; P=0.001) expression levels. Orthopedic casting tape was used to immobilize the right knee at 180˚ extension of adult female New Zealand white rabbits for 4 weeks to establish an OA model. Cartilage specimens from the medial femoral condyle of these rabbits were used for histological confirmation and immunohistochemical analyses, whereas synovial fluid was used in ELISA assays for tumor necrosis factor (TNF)­α and interleukin (IL)­1ß expression levels. Human synovial fibroblasts from the knee synovial tissues of normal patients with traumatic injury were transfected with S100B overexpression and knockdown plasmids and subjected to lipopolysaccharide (LPS) stimulation; subsequently, TNF­α and IL­1ß expression levels in conditioned medium were determined by ELISA; S100B overexpression and knockdown significantly increased and decreased the TNF­α and IL­1ß expression levels, respectively. Increased TNF­α (573.3±15.4 vs. 102.6±8.7 pg) and IL­1ß (378.6±7.2 vs. 170.1±5.8 pg) expression levels were detected in OA model rabbits compared with the Control rabbits. Additionally, S100B, fibroblast growth factor (FGF)­1 and FGF receptor (FGFR)­1 mRNA and protein expression levels were increased in OA model rabbits compared with the Control group. FGFR1 knockdown significantly decreased TNF­α and IL­1ß expression levels in LPS­stimulated S100B­overexpressing human synovial fibroblasts. S100B is involved in FGFR1 signaling­mediated inflammatory response during OA, which may be considered as a potential therapeutic target.

Three-dimensional morphological analysis of acromioclavicular joint in patients with and without subacromial erosion after hook plate fixation.

Objective To investigate the role of acromioclavicular joint morphology in the presence of subacromial erosion after hook plate fixation. Methods We retrospectively analyzed the clinical data of 36 patients (17 men, 19 women; mean age, 48.7 years; range, 21-76 years) treated with hook plate fixation for distal clavicular fractures (n = 20) or acromioclavicular joint dislocation (n = 16) from August 2011 to March 2013. The patients were divided into two groups: the subacromial erosion group (18 patients) and the normal group (18 patients). Differences in multiple anatomical parameters between the two groups were measured and compared. Results The distal clavicle-acromion angle was significantly larger in the subacromial erosion group (mean, 51.37° ± 5.59°) than in the normal group (mean, 44.20° ± 3.83°), as was the distal clavicle-coronal angle (mean, 25.44° ± 2.51° vs. 21.67° ± 4.06°, respectively). The thickness of the acromion was significantly different between men and women (9.72 ± 1.13 vs. 8.16 ± 1.89 mm, respectively). Conclusion The results of this study indicate that the distal clavicle-acromion angle and distal clavicle-coronal angle are closely correlated with the occurrence of subacromial erosion after hook plate fixation.