The N-terminal fragment of histone deacetylase 4 (1-669aa) promotes chondrocyte apoptosis via the p53-dependent endoplasmic reticulum stress pathway.

Exogenous administration of the histone deacetylation 4 (HDAC4) protein can effectively delay osteoarthritis (OA) progression. However, HDAC4 is unstable and easily degrades into N-terminal (HDAC4-NT) and C-terminal fragments, and the HDAC4-NT can exert biological effects, but little is known about its role in chondrocytes and cartilage. Thus, the roles of HDAC4-NT fragments (1-289aa, 1-326aa and 1-669aa) in chondrocytes and cartilage were evaluated via real-time cell analysis (RTCA), safranin O staining, Sirius Red staining and nanoindentation. Molecular mechanisms were profiled via whole-transcriptome sequencing (RNA-seq) and verified in vitro and in vivo by a live cell real-time monitoring system, flow cytometry, western blotting and immunohistochemistry. The results showed that 1-669aa induced chondrocyte death and cartilage injury significantly, and the differentially expressed genes (DEGs) were enriched mainly in the apoptotic term and p53 signalling pathway. The validation experiments showed that 1-669aa induced chondrocyte apoptosis via the endoplasmic reticulum stress (ERS) pathway, and up-regulated p53 expression was essential for this process. Thus, we concluded that the HDAC4-NT fragment 1-669aa induces chondrocyte apoptosis via the p53-dependent ERS pathway, suggesting that in addition to overexpressing HDAC4, preventing it from degradation may be a new strategy for the treatment of OA.

A single-cell 3D dynamic volume control system for chondrocytes.

In articular cartilage, zone-specific cellular morphology is a typical characteristic of cartilage tissue, which is related with chondrocyte function, inflammation and osteoarthritis (OA). Chondrocyte hypertrophic phenotype is a criticle physiological process which indicates a hallmark of chondrocyte terminal differentiation and bone formation. Thus, developing a in vitro cell culture system for dynamic regulation of single chondrocyte volume at a three-dimensional (3D) level is particularly necessary for understanding how physical cues of matrix microenvironment regulate chondrocyte fate and the degeneration of articular cartilage. Here, based on the soft lithography techniques, we have constructed well-defined single-cell 3D dynamic volume control system to recapitulate the physiological matrix microenvironment of single chondrocyte niche. The results of finite element analysis indicated that the stress and strain distribution in the cell culture region is homogeneous during the stretching process. Additionally, 3D dynamic volume expansion and compression of single cells in physiological or hyperphysiological can be realized in this cell culture system. Our device for single-cell 3D dynamic culture provides a microphysiological culture system for chondrocytes to explore the mechanisms of cartilage hypertrophy, as well as develops a new paradigm for functional cartilage tissue engineering and regenerative medicine.

SolidWorks software was used to design various components of 3D dynamic volume control system. Leveraging lithography microfabrication techniques, the polydimethylsiloxane (PDMS) 3D niches were fabricated with controlled geometry and volume on PDMS stretching substrate. Finite element analysis softwares (Abaqus and Comsol) were used to analyze the strain distribution of PDMS stretching substrate and single 3D niche. The elastic moduli of PDMS stretching substrate were measured using an Instron 5544. Furthermore, immunofluorescence staining was performed to assess the morphology and cytoskeletal reorganization of chondrocyte encapsulated in PDMS 3D niches. ImageJ software was used to quantitatively analyze immunofluorescence images.

Comparative Metabolome and Transcriptome Analysis Reveals the Defense Mechanism of Chinese Cabbage (Brassica rapa L. ssp. pekinensis) against Plasmodiophora brassicae Infection.

Chinese cabbage (Brassica rapa L. ssp. pekinensis) ranks among the most cultivated and consumed vegetables in China. A major threat to its production is Plasmodiophora brassicae, which causes large root tumors, obstructing nutrient and water absorption and resulting in plant withering. This study used a widely targeted metabolome technique to identify resistance-related metabolites in resistant (DH40R) and susceptible (DH199S) Chinese cabbage varieties after inoculation with P. brassicae. This study analyzed disease-related metabolites during different periods, identifying 257 metabolites linked to resistance, enriched in the phenylpropanoid biosynthesis pathway, and 248 metabolites linked to susceptibility, enriched in the arachidonic acid metabolism pathway. Key metabolites and genes in the phenylpropanoid pathway were upregulated at 5 days post-inoculation (DPI), suggesting their role in disease resistance. In the arachidonic acid pathway, linoleic acid and gamma-linolenic acid were upregulated at 5 and 22 DPI in resistant plants, while arachidonic acid was upregulated at 22 DPI in susceptible plants, leading to the conclusion that arachidonic acid may be a response substance in susceptible plants after inoculation. Many genes enriched in these pathways were differentially expressed in DH40R and DH199S. The research provided insights into the defense mechanisms of Chinese cabbage against P. brassicae through combined metabolome and transcriptome analysis.

Key roles of the superficial zone in articular cartilage physiology, pathology, and regeneration.

ABSTRACT: The superficial zone (SFZ) of articular cartilage is an important interface that isolates deeper zones from the microenvironment of the articular cavity and is directly exposed to various biological and mechanical stimuli. The SFZ is not only a crucial structure for maintaining the normal physiological function of articular cartilage but also the earliest site of osteoarthritis (OA) cartilage degeneration and a major site of cartilage progenitor cells, suggesting that the SFZ might represent a key target for the early diagnosis and treatment of OA. However, to date, SFZ research has not received sufficient attention, accounting for only about 0.58% of cartilage tissue research. The structure, biological composition, function, and related mechanisms of the SFZ in the physiological and pathological processes of articular cartilage remain unclear. This article reviews the key role of the SFZ in articular cartilage physiology and pathology and focuses on the characteristics of SFZ in articular cartilage degeneration and regeneration in OA, aiming to provide researchers with a systematic understanding of the current research status of the SFZ of articular cartilage, hoping that scholars will give more attention to the SFZ of articular cartilage in the future.

A pH-responsive novel delivery system utilizing carbon quantum dots loaded with PT2385 for targeted inhibition of HIF-2α in the treatment of osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a progressive joint disorder marked by the degradation of cartilage. Elevated concentrations of hypoxia-inducible factor-2α (HIF-2α) are intricately linked to the pathological development of OA. PT2385 has demonstrated effective inhibition of HIF-2α, thereby potentially impeding the initial advancement of OA. Nevertheless, challenges persist, including limited penetration into the deeper layers of cartilage, issues related to charge rejection, and a heightened rate of clearance from the joint. These constraints necessitate further consideration and exploration. METHODS: It has been demonstrated that PT2385 exhibits efficient inhibition of HIF-2α expression, thereby contributing to the delay in the progression of osteoarthritis. The pH-responsive attributes of carbon quantum dots, specifically those employing m-phenylenediamine (m-CQDs) coated with bovine serum albumin (BSA), have been systematically evaluated. In both in vitro settings involving cartilage explants and in vivo experiments, the efficacy of BSA-m-CQDs-PT2385 (BCP) has been confirmed in facilitating the transport of PT2385 to the middle and deep layers of cartilage. Furthermore, the BCP system demonstrates controlled drug release contingent upon alterations in environmental pH. RESULTS: While the use of PT2385 alone provides protective effects on chondrocytes within an inflamed environment, there exists an opportunity for further enhancement in its efficacy when administered via intra-articular injection. The BCP formulation, characterized by appropriate particle size and charge, facilitates seamless penetration into cartilage tissue. Additionally, BCP demonstrates the capability to release drugs in response to changes in environmental pH. In vitro experiments reveal that BCP effectively inhibits Hif-2α expression and catabolic factors in chondrocytes. Notably, cartilage explants and in vivo experiments indicate that BCP surpasses PT2385 alone in inhibiting the expression of HIF-2α and matrix metalloproteinase 13, particularly in the middle and deep layers. CONCLUSIONS: The BCP drug delivery system exhibits selective release of PT2385 in response to pH changes occurring during the progression of osteoarthritis (OA), thereby inhibiting HIF-2α expression deep within the cartilage. The use of BCP significantly augments the capacity of PT2385 to retard both cartilage degeneration and the progression of osteoarthritis. Consequently, BCP as an innovative approach utilizing m-CQDs to deliver PT2385 into articular cartilage, shows potential for treating osteoarthritis.This strategy opens new avenues for osteoarthritis treatment.

Integrated cytological and transcriptomic analyses provide new insights into restoration of pollen viability in synthetic allotetraploid Brassica carinata.

KEY MESSAGE: Upregulation of genes involved in DNA damage repair and sperm cell differentiation leads to restoration of pollen viability in synthetic allotetraploid B. carinata after chromosome doubling. Apart from the well-known contribution of polyploidy to crop improvement, polyploids can also be induced for other purposes, such as to restore the viability of sterile hybrids. The mechanism related to viability transition between the sterile allodiploid and the fertile allotetraploid after chromosome doubling are not well understood. Here, we synthesised allodiploid B. carinata (2n = 2x = 17) and allotetraploid B. carinata (2n = 4x = 34) as models to investigate the cytological and transcriptomic differences during pollen development. The results showed that after chromosome doubling, the recovery of pollen viability in allotetraploid was mainly reflected in the stabilisation of microtubule spindle morphology, normal meiotic chromosome behaviour, and normal microspore development. Interestingly, the deposition and degradation of synthetic anther tapetum were not affected by polyploidy. Transcription analysis showed that the expression of genes related to DNA repair (DMC1, RAD51, RAD17, SPO11-2), cell cycle differentiation (CYCA1;2, CYCA2;3) and ubiquitination proteasome pathway (UBC4, PIRH2, CDC53) were positively up-regulated during pollen development of synthetic allotetraploid B. carinata. In summary, these results provide some refreshing updates about the ploidy-related restoration of pollen viability in newly synthesised allotetraploid B. carinata.

Genome-Wide Identification, Expression, and Protein Analysis of CKX and IPT Gene Families in Radish (Raphanus sativus L.) Reveal Their Involvement in Clubroot Resistance.

Cytokinins (CKs) are a group of phytohormones that are involved in plant growth, development, and disease resistance. The isopentenyl transferase (IPT) and cytokinin oxidase/dehydrogenase (CKX) families comprise key enzymes controlling CK biosynthesis and degradation. However, an integrated analysis of these two gene families in radish has not yet been explored. In this study, 13 RsIPT and 12 RsCKX genes were identified and characterized, most of which had four copies in Brassica napus and two copies in radish and other diploid Brassica species. Promoter analysis indicated that the genes contained at least one phytohormone or defense and stress responsiveness cis-acting element. RsIPTs and RsCKXs were expanded through segmental duplication. Moreover, strong purifying selection drove the evolution of the two gene families. The expression of the RsIPT and RsCKX genes distinctly showed diversity in different tissues and developmental stages of the root. Expression profiling showed that RsCKX1-1/1-2/1-3 was significantly upregulated in club-resistant materials during primary infection, suggesting their vital function in clubroot resistance. The interaction network of CKX proteins with similar 3D structures also reflected the important role of RsCKX genes in disease resistance. This study provides a foundation for further functional study on the IPT and CKX genes for clubroot resistance improvement in Raphanus.

[Kinematic gait analysis for patients with meniscus injury].

OBJECTIVE: To investigate application of the Codamotion 2CX1 three-dimensional dynamic joint motion capture system to analyze the kinematic characteristics of patients with different degrees of meniscus injury. METHODS: From December 2020 to June 2022, 135 patients with meniscus injury and recruited normal people were collected, including 82 males and 53 females, aged 14 to 29 years old, with disease duration of 1 to 3 months. Combined with clinical symptoms and MRI examination, the diagnosis of meniscus injury was confirmed, and the patients were divided into stages, including 37 cases of grade 0(normal), 30 cases of gradeⅠ, 33 cases of gradeⅡ, 35 cases of grade Ⅲ according to Stoller grading standard. Subjects in each group were tested walking by using Codamotion 2CX1 three-dimensional dynamic joint motion capture system. Quantitative indexes of walking and kinematics were collected, including knee flexion and extension, internal and external rotation and internal and external turning, and their kinematics were analyzed. RESULTS: In the distribution of knee flexion/extension, there were significant differences in maximum knee flexion, minimum knee extension and knee flexion and extension range among 4 groups(P<0.05). In the distribution of internal/external rotation of knee joint, there were significant differences in the range of internal rotation and rotation of knee joint among 4 groups(P<0.05). In the distribution of internal/external turning of knee joint, there were significant differences in the range of internal and external turning of knee joint among 4 groups(P<0.05). The clinical stage progression was positively correlated with the range of motion of knee extension, external rotation, internal and external turning and turning range(P<0.05). It was negatively correlated with knee flexion, internal rotation, flexion extension and rotation range(P<0.05). The internal and external rotation angles of knee joint could be used as independent factors influencing the clinical stage of meniscus injury (P=0.006, 0.019<0.05). CONCLUSION: The knee movement of patients with meniscus injury has obvious changes, and the changes are different under different clinical stages. Gait analysis provides a reliable basis for the kinematic analysis of meniscus injury, helps to better understand the kinematic indexes of joints, and provides a reliable auxiliary diagnosis and treatment plan, which provides a new direction for the follow-up medical research.

Effect of patellofemoral joint overstuffing following total knee arthroplasty without patella resurfacing on clinical efficacy and related factors analysis.

OBJECTIVE: To analyze the influencing factors for patellofemoral joint (PFJ) overstuffing following total knee arthroplasty (TKA) without patella resurfacing, and explore the effect of PFJ overstuffing on clinical efficacy. METHODS: A retrospective analysis was conducted on 168 patients with end-stage knee osteoarthritis who underwent TKA without patella resurfacing at our hospital between Match 2019 and September 2021. The clinical data of these patients were retrospectively analyzed. In this study, PFJ overstuffing was defined as a postoperative PFJ distance greater than 1 mm compared to the preoperative measurement. The occurrence of postoperative PFJ overstuffing was counted. The patients were divided into the overstuffing group (n = 109) and the non-overstuffing group (n = 59) to count the patellar thickness and thickness of femoral anterior condyle in all patients before and after surgery, and analyze the influencing factors for postoperative PFJ overstuffing in such patients. Patients were followed up for 2 years to compare the recovery time of postoperative pain, score of visual analogue scale (VAS) and flexion activity between the two groups. RESULTS: There was no significant difference in patellar thickness between preoperative and postoperative measurements of the patients (P > 0.05). However, the thickness of the femoral anterior condyle and the PFJ distance after surgery increased significantly compared with those before surgery (P < 0.05). Among the 168 patients, 109 cases (64.88%) experienced PFJ overstuffing. The risk of PFJ overstuffing was higher in female patients than in male (P < 0.05). The preoperative thickness of the femoral anterior condyle in the overstuffing group was significantly smaller compared to the non-overstuffing group (P < 0.001). Compared with the non-overstuffing group, the overstuffing group had longer recovery time of postoperative pain (P < 0.05), and had lower flexion activity at 2 years after surgery (P < 0.001). However, no significant difference was found in VAS score between the overstuffing group and the non-overstuffing group at 2 years after surgery (P > 0.05). Spearman rank correlation analysis indicated females tend to have a lower preoperative thickness of the femoral anterior condyle (r=-0.424, P < 0.001), as well as a positive postoperative PFJ overstuffing (r = 0.237, P < 0.05). Furthermore, there was a negative correlation between preoperative thickness of the femoral anterior condyle and postoperative PFJ overstuffing (r=-0.540, P < 0.001). CONCLUSION: Following TKA without patella resurfacing, there is a high risk of PFJ overstuffing, particularly among female patients and those with a small thickness of the femoral anterior condyle. Therefore, special attention should be given to these high-risk groups during clinical treatment.

Characterization of the gut microbiota and fecal metabolome in the osteosarcoma mouse model.

Previous studies have reported the correlation between gut microbiota (GM), GM-derived metabolites, and various intestinal and extra-intestinal cancers. However, limited studies have investigated the correlation between GM, GM-derived metabolites, and osteosarcoma (OS). This study successfully established a female BALB/c nude mouse model of OS. Mice (n = 14) were divided into the following two groups (n = 7/group): OS group named OG, injected with Saos-2 OS cells; normal control group named NCG, injected with Matrigel. The GM composition and metabolites were characterized using 16S rDNA sequencing and untargeted metabolomics, respectively. Bioinformatics analysis revealed that amino acid metabolism was dysregulated in OS. The abundances of bone metabolism-related genera Alloprevotella, Rikenellaceae_RC9_gut_group, and Muribaculum were correlated with amino acid metabolism, especially histidine metabolism. These findings suggest the correlation between GM, GM-derived metabolites, and OS pathogenesis. Clinical significance: The currently used standard therapeutic strategies for OS, including surgery, chemotherapy, and radiation, are not efficacious. The findings of this study provided novel insights for developing therapeutic, diagnostic, and prognostic strategies for OS.

HDAC4 represses ER stress induced chondrocyte apoptosis by inhibiting ATF4 and attenuates cartilage degeneration in an osteoarthritis rat model.

BACKGROUND: The present study evaluated whether the lack of histone deacetylase 4 (HDAC4) increases endoplasmic reticulum stress-induced chondrocyte apoptosis by releasing activating transcription factor 4 (ATF4) in human osteoarthritis (OA) cartilage degeneration. METHODS: Articular cartilage from the tibial plateau was obtained from patients with OA during total knee replacement. Cartilage extracted from severely damaged regions was classified as degraded cartilage, and cartilage extracted from a relatively smooth region was classified as preserved cartilage. Terminal deoxynucleotidyl transferase dUTP nick end labeling staining was used to detect chondrocyte apoptosis. HDAC4, ATF4, and C/EBP homologous protein (CHOP) expression levels were measured using immunohistochemistry staining and real-time quantitative PCR. Chondrocytes were transfected with HDAC4 or HDAC4 siRNA for 24 h and stimulated with 300 µM H2O2 for 12 h. The chondrocyte apoptosis was measured using flow cytometry. ATF4, CHOP, and caspase 12 expression levels were measured using real-time quantitative PCR and western blotting. Male Sprague-Dawley rats (n = 15) were randomly divided into three groups and transduced with different vectors: ACLT + Ad-GFP, ACLT + Ad-HDAC4-GFP, and sham + Ad-GFP. All rats received intra-articular injections 48 h after the operation and every three weeks thereafter. Cartilage damage was assessed using Safranin O staining and quantified using the Osteoarthritis Research Society International score. ATF4, CHOP, and collagen II expression were detected using immunohistochemistry, and chondrocyte apoptosis was detected using terminal deoxynucleotidyl transferase dUTP nick end labeling staining. RESULTS: The chondrocyte apoptosis was higher in degraded cartilage than in preserved cartilage. HDAC4 expression was lower in degraded cartilage than in preserved cartilage. ATF4 and CHOP expression was increased in degraded cartilage. Upregulation of HDAC4 in chondrocytes decreased the expression of ATF4, while the expression of ATF4 was increased after downregulation of HDAC4. Upregulation of HDAC4 decreased the chondrocyte apoptosis under endoplasmic reticulum stress, and chondrocyte apoptosis was increased after downregulation of HDAC4. In a rat anterior cruciate ligament transection OA model, adenovirus-mediated transduction of HDAC4 was administered by intra-articular injection. We detected a stronger Safranin O staining with lower Osteoarthritis Research Society International scores, lower ATF4 and CHOP production, stronger collagen II expression, and lower chondrocyte apoptosis in rats treated with Ad-HDAC4. CONCLUSION: The lack of HDAC4 expression partially contributes to increased ATF4, CHOP, and endoplasmic reticulum stress-induced chondrocyte apoptosis in OA pathogenesis. HDAC4 attenuates cartilage damage by repressing ATF4-CHOP signaling-induced chondrocyte apoptosis in a rat model of OA.

Integrated proteomics and metabolomics analysis of sclerosis-related proteins and femoral head necrosis following internal fixation of femoral neck fractures.

Femoral head necrosis (FHN) is a serious complication after femoral neck fractures (FNF), often linked to sclerosis around screw paths. Our study aimed to uncover the proteomic and metabolomic underpinnings of FHN and sclerosis using integrated proteomics and metabolomics analyses. We identified differentially expressed proteins (DEPs) and metabolites (DEMs) among three groups: patients with FNF (Group A), sclerosis (Group B), and FHN (Group C). Using the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses, we examined the roles of these proteins and metabolites. Our findings highlight the significant differences across the groups, with 218 DEPs and 44 DEMs identified between the sclerosis and FNF groups, 247 DEPs and 31 DEMs between the FHN and sclerosis groups, and a stark 682 DEPs and 94 DEMs between the FHN and FNF groups. Activities related to carbonate dehydratase and hydrolase were similar in the FHN and sclerosis groups, whereas extracellular region and lysosome were prevalent in the FHN and FNF groups. Our study also emphasized the involvement of the PI3K-Akt pathway in sclerosis and FHN. Moreover, the key metabolic pathways were implicated in glycerophospholipid metabolism and retrograde endocannabinoid signaling. Using western blotting, we confirmed the pivotal role of specific genes/proteins such as ITGB5, TNXB, CA II, and CA III in sclerosis and acid phosphatase 5 and cathepsin K in FHN. This comprehensive analyses elucidates the molecular mechanisms behind sclerosis and FHN and suggests potential biomarkers and therapeutic targets, paving the way for improved treatment strategies. Further validation of the findings is necessary to strengthen the robustness and reliability of the results.

Fine mapping and candidate gene analysis of CRA8.1.6, which confers clubroot resistance in turnip (Brassica rapa ssp. rapa).

Clubroot disease poses a significant threat to Brassica crops, necessitating ongoing updates on resistance gene sources. In F2 segregants of the clubroot-resistant inbred line BrT18-6-4-3 and susceptible DH line Y510, the genetic analysis identified a single dominant gene responsible for clubroot resistance. Through bulk segregant sequencing analysis and kompetitive allele-specific polymerase chain reaction assays, CRA8.1.6 was mapped within 110 kb (12,255-12,365 Mb) between markers L-CR11 and L-CR12 on chromosome A08. We identified B raA08g015220.3.5C as the candidate gene of CRA8.1.6. Upon comparison with the sequence of disease-resistant material BrT18-6-4-3, we found 249 single-nucleotide polymorphisms, seven insertions, six deletions, and a long terminal repeat (LTR) retrotransposon (5,310 bp) at 909 bp of the first intron. However, the LTR retrotransposon was absent in the coding sequence of the susceptible DH line Y510. Given the presence of a non-functional LTR insertion in other materials, it showed that the LTR insertion might not be associated with susceptibility. Sequence alignment analysis revealed that the fourth exon of the susceptible line harbored two deletions and an insertion, resulting in a frameshift mutation at 8,551 bp, leading to translation termination at the leucine-rich repeat domain's C-terminal in susceptible material. Sequence alignment of the CDS revealed a 99.4% similarity to Crr1a, which indicate that CRA8.1.6 is likely an allele of the Crr1a gene. Two functional markers, CRA08-InDel and CRA08-KASP1, have been developed for marker-assisted selection in CR turnip cultivars. Our findings could facilitate the development of clubroot-resistance turnip cultivars through marker-assisted selection.

Transcriptome analysis reveals the potential lncRNA-mRNA modules involved in genetic male sterility and fertility of Chinese cabbage (brassica rapa L. ssp. pekinensis).

BACKGROUND: Long non-coding RNAs (lncRNAs) play a crucial role in regulating gene expression vital for the growth and development of plants. Despite this, the role of lncRNAs in Chinese cabbage (Brassica rapa L. ssp. pekinensis) pollen development and male fertility remains poorly understood. RESULTS: In this study, we characterized a recessive genic male sterile mutant (366-2 S), where the delayed degradation of tapetum and the failure of tetrad separation primarily led to the inability to form single microspores, resulting in male sterility. To analyze the role of lncRNAs in pollen development, we conducted a comparative lncRNA sequencing using anthers from the male sterile mutant line (366-2 S) and the wild-type male fertile line (366-2 F). We identified 385 differentially expressed lncRNAs between the 366-2 F and 366-2 S lines, with 172 of them potentially associated with target genes. To further understand the alterations in mRNA expression and explore potential lncRNA-target genes (mRNAs), we performed comparative mRNA transcriptome analysis in the anthers of 366-2 S and 366-2 F at two stages. We identified 1,176 differentially expressed mRNAs. Remarkably, GO analysis revealed significant enrichment in five GO terms, most notably involving mRNAs annotated as pectinesterase and polygalacturonase, which play roles in cell wall degradation. The considerable downregulation of these genes might contribute to the delayed degradation of tapetum in 366-2 S. Furthermore, we identified 15 lncRNA-mRNA modules through Venn diagram analysis. Among them, MSTRG.9997-BraA04g004630.3 C (ß-1,3-glucanase) is associated with callose degradation and tetrad separation. Additionally, MSTRG.5212-BraA02g040020.3 C (pectinesterase) and MSTRG.13,532-BraA05g030320.3 C (pectinesterase) are associated with cell wall degradation of the tapetum, indicating that these three candidate lncRNA-mRNA modules potentially regulate pollen development. CONCLUSION: This study lays the foundation for understanding the roles of lncRNAs in pollen development and for elucidating their molecular mechanisms in regulating male sterility in Chinese cabbage.

In vitro corrosion and cytocompatibility of Mg-Zn-Ca alloys coated with FHA.

In the field of orthopedics, it's crucial to effectively slow down the degradation rate of Mg alloys. This study aims to improve the degradation behavior of Mg-Zn-Ca alloys by electrodepositing fluorohydroxyapatite (FHA). We investigated the microstructure and bond strength of the deposition, as well as degradation and cellular reactions. After 15-30 days of degradation in Hanks solution, FHA deposited alloys showed enhanced stability and less pH change. The strong interfacial bond between FHA and the Mg-Zn-Ca substrate was verified through scratch tests (Critical loads: 10.73 ± 0.014 N in Mg-Zn-0.5Ca alloys). Cellular studies demonstrated that FHA-coated alloys exhibited good cytocompatibility and promoted the growth of MC3T3-E1 cells. Further tests showed FHA-coated alloys owed improved early bone mineralization and osteogenic properties, especially in Mg-Zn-0.5Ca. This research highlighted the potential of FHA-coated Mg-Zn-0.5Ca alloys in orthopedics applications.

[Screw versus Kirschner wire fixation for lateral humeral condyle fractures in children:a meta analysis].

OBJECTIVE: To compare screw versus Kirschner wire fixation in the treatment of lateral humeral condyle fractures in children. METHODS: A systematic search was conducted in PubMed, Embase, the Cochrane library, Web of Science, China National Knowledge Internet(CNKI), Wanfang Datebase from in ception to February 2022. Studies comparing screws and Kirschner wire fixation in the treatment of lateral humeral condyle fractures in children were included. Outcome measures included and excluded by a set of inclusion and exclusion criteria and evaluated for their quality, their excellent and good rate of fracture healing, malunion, delayed union or nonunion, infection, limitation of elbow flexion or extension(>10°) were extracted and analyzed using software Rev Man 5.3. RESULTS: A total of 9 retrospective studies involving 647 patients were included, with 255 patients in the screw fixation group(including screw combined with Kirschner wire) and 392 patients in the Kirschner wire fixation group. Meta analysis showed the following:infection rate in the screw group was significantly lower than that in the Kirschner wire group[OR=0.22, 95%CI(0.09, 0.56), P=0.001]. There were no significant differences between the 2 groups in excellent and good rate of fracture healing, malunion rate(P>0.05). Subgroup analysis showed that infection rate in the screw-only group was significantly lower than that in the Kirschner wire group[OR=0.18, 95%CI(0.05, 0.65), P=0.009]. CONCLUSION: For lateral humeral condyle fractures, Screw fixation alone had a lower infection rate than kirschner wire fixation and screw combined with Kirschner wire fixation. There were no significant differences in the excellent and good rate of fracture healing, malunion. In terms of postoperative efficacy and safety of internal fixation, orthopaedic surgeons are more likely to recommend screws for fixation of lateral humeral condyle fractures in children.

MiR-134-5p inhibits the malignant phenotypes of osteosarcoma via ITGB1/MMP2/PI3K/Akt pathway.

Micro RNAs (miRs) have been implicated in various tumorigenic processes. Osteosarcoma (OS) is a primary bone malignancy seen in adolescents. However, the mechanism of miRs in OS has not been fully demonstrated yet. Here, miR-134-5p was found to inhibit OS progression and was also expressed at significantly lower levels in OS tissues and cells relative to normal controls. miR-134-5p was found to reduce vasculogenic mimicry, proliferation, invasion, and migration of OS cells, with miR-134-5p knockdown having the opposite effects. Mechanistically, miR-134-5p inhibited expression of the ITGB1/MMP2/PI3K/Akt axis, thus reducing the malignant features of OS cells. In summary, miR-134-5p reduced OS tumorigenesis by modulation of the ITGB1/MMP2/PI3K/Akt axis, suggesting the potential for using miR-134-5p as a target for treating OS.

Intra-articular injection of miRNA-1 agomir, a novel chemically modified miRNA agonists alleviates osteoarthritis (OA) progression by downregulating Indian hedgehog in rats.

Our objective in this study is to determine whether intra-articular injection of miRNA-1 can attenuate the progression of OA in rats by down regulating Ihh. Knee chondrocytes were isolated from male Sprague-Dawley rats aged 2-3 days. Second-generation chondrocytes were transfected with miR-1 mimic and empty vector with lipo3000 for 6 h and then stimulated with 10 ng/mL IL-1ß for 24 h. OA-related and cartilage matrix genes were quantified using real-time quantitative polymerase chain reaction (RT-qPCR). Two-month-old male Sprague-Dawley rats were divided into three groups (n = 30?): sham operation group + 50 µL saline, anterior cruciate ligament transection (ACLT) group + 50 µL miR-1 agomir (concentration), and control group ACLT + 50 µL miR-1 agomir. Treatment was started one week after the operation. All animals were euthanized eight weeks after the operation. X-rays and micro-CT were used to detect imaging changes in the knee joints. FMT was used to monitor joint inflammation in vivo. Safranin O staining was used to detect morphological changes in articular cartilage. Immunohistochemistry was used to detect Col2, Col10, metalloproteinase-13 (MMP-13). RT-qPCR was used to detect gene changes includingmiR-1, Col2, Col10, MMP-13, Ihh, Smo, Gli1, Gli2, and Gli3. Overexpression of miR-1 in IL-1ß-stimulated chondrocytes reduced the levels of Ihh, MMP-13, and Col10 but increased the levels of Col2 and aggrecan. Intra-articular injection of miR-1 agomir reduced osteophyte formation, inflammation, and prevented cartilage damage. RT-qPCR results indicated that the miR-1 agomir increased articular cartilage anabolism and inhibited cartilage catabonism. miR-1 can attenuate the progression of OA by downregulating Ihh.

Deficient gait function despite effect index of the Western Ontario and McMaster university osteoarthritis index score considered cured one year after bilateral total knee arthroplasty.

BACKGROUND: To clarify the value of gait analysis and its consistency with traditional scoring scales for the evaluation of knee joint function after total knee arthroplasty (TKA). METHODS: This study included 25 patients with knee osteoarthritis (KOA) who underwent bilateral TKA, and 25 conditionally matched healthy individuals, categorised into the experimental and control groups, respectively. Patients in the experimental group underwent gait analysis and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) evaluation before and 1 year after TKA. Weight-bearing balance and walking stability were assessed using discrete trends of relevant gait indicators. Pearson's correlation analysis was performed on the gait and WOMAC score data of the experimental group before and after TKA. RESULTS: One year after TKA, patients' gait indices (except gait cycle) were significantly better than before surgery, but significantly worse than that of the control group (P < 0.01). The shape of patients' plantar pressure curves did not return to normal. Additionally, the discrete trend of related gait indicators reflecting weight-bearing balance and walking stability were smaller than before TKA, but still greater than that of the control group. The WOMAC scores of patients 1 year after TKA were significantly lower than those before TKA (P < 0.001), and the efficacy index was > 80%. The WOMAC scores and gait analysis results were significantly correlated before TKA (P < 0.05). CONCLUSIONS: Gait analysis should be used in conjunction with scoring scales to assess joint functions.

[Meta-analysis of autologous bone grafts and bone substitute for the treatment of tibial plateau fractures].

OBJECTIVE: To explore clinical efficacy of autologous bone grafts and bone substitute for the treatment of tibial plateau fractures by Meta analysis. METHODS: Controlled clinical studies on autogenous bone transplantation and bone substitutes in treating tibial plateau fractures published on PubMed,Web of Science,CNKI,Wanfang and other databases from January 2005 to August 2022 were searched by computer. Literature screening and data extraction were performed according to randomized controlled trial(RCT),and the quality of RCT were evaluated by using intervention meta-analysis criteria in Cochrane manual. Meta-analysis of joint depression,secondary collapse rate of articular surface,blood loss,operative time and infection rate between two methods were performed by Rev Man 5.3 software. RESULTS: Seven RCT studies (424 patients) were included,296 patients in bone replacement group and 128 patients in autograft group. Operative time [MD=-16.79,95%CI(-25.72,-7.85),P=0.000 2] and blood loss[MD=-70.49,95%CI(-79.34,-61.65),P<0.000 01] between two groups had statistically differences,while joint depression[MD=-0.17,95%CI(-0.91,0.58),P=0.66],secondary collapse rate of joint surface[RR=-0.74, 95%CI(0.35,1.57),P=0.43],infection rate [RR=1.21,95%CI(0.31,4.70),P=0.78] between two groups had no differences. CONCLUSION: The effects of bone substitute and autograft for the treatment of tibial plateau fracture have similar effects in terms of joint depression,secondary articular surface collapse rate and infection rate. However,compared with autologous bone transplantation,bone replacement could reduce blood loss and shorten operation time.