The Efficacy and Safety of an Intra-articular Dual-Acting Antibacterial Agent (TNP-2092) for Implant Infection-Associated Methicillin-Resistant Staphylococcus aureus.

Owing to the presence of microbial biofilm on the implant, the eradication of biofilm-associated infections poses a challenge for antibiotic therapies. The study aimed to investigate the efficacy and safety of the novel antibiotic agent TNP-2092 in the context of implant infections. In vivo, rats with periprosthetic joint infection (PJI) treated with antibiotics showed an increase in body weight and decrease in swelling, temperature, and width of knee, compared with the control group. Meanwhile, inflammatory markers in synovium and serum were decreased in the TNP-2092 group, consistent with the pathological results. Moreover, TNP-2092 was effective in eliminating bacteria and disruption biofilm formation, and further alleviated the abnormal bone absorption and reactive bone changes around the prosthesis. In conclusion, intra-articular injection of TNP-2092 is safe and effective in treating knee PJI in a rat model. The study provides a foundation for the future utilization of TNP-2092 in the management of implant-related infections.

Genetic evidence of the causal relationship between chronic liver diseases and musculoskeletal disorders.

BACKGROUND: Chronic liver diseases constitute a major global public health burden, posing a substantial threat to patients' daily lives and even survival due to the potential development of musculoskeletal disorders. Although the relationship between chronic liver diseases and musculoskeletal disorders has received extensive attention, their causal relationship has not been comprehensively and systematically investigated. METHODS: This study aimed to assess the causal relationships between viral hepatitis, primary biliary cholangitis, primary sclerosing cholangitis (PSC), liver cirrhosis, and hepatocellular carcinoma (HCC) with osteoporosis, osteoarthritis, and sarcopenia through bidirectional Mendelian randomization (MR) research. The traits related to osteoporosis and osteoarthritis included both overall and site-specific phenotypes, and the traits linked to sarcopenia involved indicators of muscle mass and function. Random-effect inverse-variance weighted (IVW), weighted median, MR-Egger, and Causal Analysis Using the Summary Effect Estimates were used to evaluate causal effects, with IVW being the main analysis method. To enhance robustness, sensitivity analyses were performed using Cochran's Q test, MR-Egger intercept, MR-PRESSO global test, funnel plots, leave-one-out analyses, and latent causal variable model. RESULTS: The forward MR analysis indicated that PSC can reduce forearm bone mineral density (beta = - 0.0454, 95% CI - 0.0798 to - 0.0110; P = 0.0098) and increase the risk of overall osteoarthritis (OR = 1.012, 95% CI 1.002-1.022; P = 0.0247), while HCC can decrease grip strength (beta = - 0.0053, 95% CI - 0.008 to - 0.0025; P = 0.0002). The reverse MR analysis did not find significant causal effects of musculoskeletal disorders on chronic liver diseases. Additionally, no heterogeneity or pleiotropy was detected. CONCLUSIONS: These findings corroborate the causal effects of PSC on osteoporosis and osteoarthritis, as well as the causal impact of HCC on sarcopenia. Thus, the implementation of comprehensive preventive measures is imperative for PSC and HCC patients to mitigate the risk of musculoskeletal disorders, ultimately improving their quality of life.

Autophagy inhibition mediated by intrauterine miR-1912-3p/CTSD programming participated in the susceptibility to osteoarthritis induced by prenatal dexamethasone exposure in male adult offspring rats.

Autophagy inhibition is known to be involved in the development of adult osteoarthritis. Dexamethasone, as a synthetic glucocorticoid, is widely used for premature delivery and related pregnancy diseases in clinics. We have previously shown that prenatal dexamethasone exposure (PDE) was associated with increased susceptibility to postnatal osteoarthritis in offspring. However, whether the occurrence of fetal-originated adult osteoarthritis induced by PDE is related to autophagy remains unclear. In this study, we first found that PDE could increase the mRNA and protein expression of cartilage matrix-degrading enzymes (MMP3, MMP13, and ADAMTS5) and decrease the cartilage matrix contents in adult offspring, and the in vitro results suggested that this might be related to the autophagy inhibition of chondrocytes. Further, we demonstrated a persistent autophagy inhibition with autolysosome accumulation, low expression of cathepsin D (CTSD), increased H3K9ac level, and expression of miR-1912-3p in the cartilage of PDE offspring from fetus to adulthood. In vitro experiments showed that dexamethasone inhibited autophagy flux and CTSD expression in fetal chondrocytes, while overexpression of CTSD could alleviate the inhibition of autophagic flux induced by dexamethasone. Finally, we confirmed that dexamethasone increased the H3K9ac level and expression of miR-1912-3p through activation of the glucocorticoid receptor (GR), resulting in the decreased expression of CTSD and inhibition of autophagy flux in fetal chondrocytes. In conclusion, intrauterine miR-1912-3p/CTSD programming-mediated autophagy inhibition promoted the susceptibility to osteoarthritis in PDE adult offspring rats. This study provides new ideas for exploring early prevention and therapeutic targets in fetal-originated osteoarthritis.

Multi-organ developmental toxicity and its characteristics in fetal mice induced by dexamethasone at different doses, stages, and courses during pregnancy.

Dexamethasone is widely used in pregnant women at risk of preterm birth to reduce the occurrence of neonatal respiratory distress syndrome and subsequently reduce neonatal mortality. Studies have suggested that dexamethasone has developmental toxicity, but there is a notable absence of systematic investigations about its characteristics. In this study, we examined the effects of prenatal dexamethasone exposure (PDE) on mother/fetal mice at different doses (0.2, 0.4, or 0.8 mg/kg b.i.d), stages (gestational day 14-15 or 16-17) and courses (single- or double-course) based on the clinical practice. Results showed that PDE increased intrauterine growth retardation rate, and disordered the serum glucose, lipid and cholesterol metabolic phenotypes, and sex hormone level of mother/fetal mice. PDE was further discovered to interfere with the development of fetal lung, hippocampus and bone, inhibits steroid synthesis in adrenal and testis, and promotes steroid synthesis in the ovary and lipid synthesis in the liver, with significant effects observed at high dose, early stage and double course. The order of severity might be: ovary > lung > hippocampus/bone > others. Correlation analysis revealed that the decreased serum corticosterone and insulin-like growth factor 1 (IGF1) levels were closely related to PDE-induced low birth weight and abnormal multi-organ development in offspring. In conclusion, this study systematically confirmed PDE-induced multi-organ developmental toxicity, elucidated its characteristics, and proposed the potential "glucocorticoid (GC)-IGF1" axis programming mechanism. This research provided an experimental foundation for a comprehensive understanding of the effect and characteristics of dexamethasone on fetal multi-organ development, thereby guiding the application of "precision medicine" during pregnancy.

Construction of miRNA-mRNA Regulatory Network to Identify Potential Biomarkers in Infantile Hemangioma by Integrated Bioinformatics Analysis.

Infantile hemangioma (IH) is the most common vascular tumor among infants and children. However, the understanding of pathogenesis about IH has not been fully elucidated, and the potential diagnostic maker remains further explored. In this study, we aimed to find miRNAs as potential biomarkers of IH through bioinformatic analysis. The microarray datasets GSE69136, GSE100682 were downloaded from the GEO database. The co-expressed differential miRNAs were identified by analyzing these two datasets. The downstream common target genes were predicted by the ENCORI, Mirgene, miRWalk, and Targetscan databases. GO annotation and KEGG pathway enrichment analysis for target genes were performed. The STRING database and Cytoscape software were used to construct the protein-protein interaction network and screen hub genes. Then potential diagnostic markers for IH were further screened and identified by using Receiver operating characteristic curve analysis. A total of thirteen co-expressed up-regulated miRNAs were screened out in the above two datasets, and 778 down-regulated target genes were then predicted. GO annotation and KEGG pathway enrichment analysis indicated that the common target genes strongly correlated with IH. Through the DEM-hub gene network construction, six miRNAs associated with the hub genes were identified. Finally, has-miR-522-3p, has-miR-512-3p, has-miR-520a-5p with high diagnostic values were screened out by receiver operating characteristic analysis. In the study, the potential miRNA-mRNA regulatory network was firstly constructed in IH. And, the three miRNAs might be used as potential biomarkers for IH, which also provided novel strategies for the therapeutic intervention of IH.

Simvastatin promotes rat Achilles tendon-bone interface healing by promoting osteogenesis and chondrogenic differentiation of stem cells.

To investigate the effect and mechanism of simvastatin on cell components of tendon-bone healing interface. The tendon-bone healing model was established by inserting the end of the Achilles tendon into the tibial tunnel on 24 rats, and simvastatin was used locally at the tendon-bone interface. Healing was evaluated at 8 weeks by mechanical testing, micro-CT, and qualitative histology including H&E, Toluidine blue, and immunohistochemical staining. In vitro, bone marrow stromal cells (BMSCs) and tendon-derived mesenchymal stem cells (TDSCs) underwent osteogenic and chondrogenic differentiation respectively by plate co-culture. An analysis was performed on days 7 and 14 of cell differentiation. Biomechanical testing demonstrated a significant increase in maximum stiffness in the simvastatin-treated group. Micro-CT analysis showed that the bone tunnels in the simvastatin group were smaller in diameter and had higher bone density. H&E and Toluidine blue staining demonstrated that tendon-bone healing was significantly greater with better tissue arrangement and more extracellular matrix in the simvastatin-treated group than that in the control group, and immunohistochemical staining showed the expression of VEGF in simvastatin group was significantly higher. Histological staining and RT-PCR confirmed that simvastatin could promote the differentiation of co-cultured BMSCs and TDSCs into osteoblasts and chondroblasts, respectively. The effect of promoting osteogenic differentiation was more tremendous at 14 days, while its effect on promoting chondroblast differentiation was more evident on the 7th day of differentiation. In conclusion, local administration of simvastatin can promote the tendon-bone healing by enhancing neovascularization, chondrogenesis, and osteogenesis in different stages of the tendon-bone healing process.

Stage-, dose-, and course-dependent inhibition of prenatal amoxicillin exposure on fetal articular cartilage development in fetal mice.

Amoxicillin is widely used in the treatment of infectious diseases during pregnancy; however, the effects of prenatal amoxicillin exposure (PAE) on fetal development remain largely unknown. Therefore, this study aimed to investigate the toxic effects of PAE on fetal cartilage at different stage-, dose-, and course. Pregnant Kunming mice were orally administered 300 mg/kg·d (converted from clinical dose) amoxicillin on gestational days (GD) 10-12 or 16-18 (mid or late pregnancy stage), 150 or 300 mg/kg.d amoxicillin on GD16-18 (different doses), 300 mg/kg·d amoxicillin on GD16 (single course) or 16-18 (multiple courses), respectively. The fetal articular cartilage of the knee was collected on GD18. The number of chondrocytes and the expression of matrix synthesis/degradation, proliferation/apoptosis-related markers, and the TGF-ß signaling pathway were detected. The results showed that the number of chondrocytes and the expression of matrix synthesis markers were reduced in male fetal mice treated with PAE (GD16-18, 300 mg/kg.d, single course and multiple courses), whereas the above indices in female mice showed no changes. The inhibited expression of PCNA, increased expression of Caspase-3, and down-regulated expression of the TGF-ß signaling pathway were found in male PAE fetal mice. Accordingly, PAE exerted its "toxic effect window" on the knee cartilage development in male fetal mice, which manifested as reduced chondrocyte number and inhibited expression of matrix synthesis at a clinical dose of multiple courses in the late pregnancy stage. This study provides a theoretical and experimental basis for elucidating the risk of chondrodevelopmental toxicity associated with amoxicillin during pregnancy.

LOX overexpression programming mediates the osteoclast mechanism of low peak bone mass in female offspring rats caused by pregnant dexamethasone exposure.

BACKGROUND: Osteoporosis is a degenerative disease characterized by reduced bone mass, with low peak bone mass being the predominant manifestation during development and having an intrauterine origin. Pregnant women at risk of preterm delivery are commonly treated with dexamethasone to promote fetal lung development. However, pregnant dexamethasone exposure (PDE) can lead to reduced peak bone mass and susceptibility to osteoporosis in offspring. In this study, we aimed to investigate the mechanism of PDE-induced low peak bone mass in female offspring from the perspective of altered osteoclast developmental programming. METHODS: 0.2 mg/kg.d dexamethasone was injected subcutaneously into rats on gestation days (GDs) 9-20. Some pregnant rats were killed at GD20 to remove fetal rat long bones, the rest were delivered naturally, and some adult offspring rats were given ice water swimming stimulation for two weeks. RESULTS: The results showed that the fetal rat osteoclast development was inhibited in the PDE group compared with the control group. In contrast, the adult rat osteoclast function was hyperactivation with reduced peak bone mass. We further found that the promoter region methylation levels of lysyl oxidase (LOX) were decreased, the expression was increased, and the production of reactive oxygen species (ROS) was raised in PDE offspring rat long bone before and after birth. Combined in vivo and in vitro experiments, we confirmed that intrauterine dexamethasone promoted the expression and binding of the glucocorticoid receptor (GR) and estrogen receptor ß (ERß) in osteoclasts and mediated the decrease of LOX methylation level and increase of expression through upregulation of 10-11 translocator protein 3 (Tet3). CONCLUSIONS: Taken together, we confirm that dexamethasone causes osteoclast LOX hypomethylation and high expression through the GR/ERß/Tet3 pathway, leading to elevated ROS production and that this intrauterine epigenetic programming effect can be carried over to postnatal mediating hyperactivation in osteoclast and reduced peak bone mass in adult offspring. This study provides an experimental basis for elucidating the mechanism of osteoclast-mediated intrauterine programming of low peak bone mass in female offspring of PDE and for exploring its early targets for prevention and treatment. Video Abstract.

Prenatal ethanol exposure and changes in fetal neuroendocrine metabolic programming.

Prenatal ethanol exposure (PEE) (mainly through maternal alcohol consumption) has become widespread. However, studies suggest that it can cause intrauterine growth retardation (IUGR) and multi-organ developmental toxicity in offspring, and susceptibility to various chronic diseases (such as neuropsychiatric diseases, metabolic syndrome, and related diseases) in adults. Through ethanol's direct effects and its indirect effects mediated by maternal-derived glucocorticoids, PEE alters epigenetic modifications and organ developmental programming during fetal development, which damages the offspring health and increases susceptibility to various chronic diseases after birth. Ethanol directly leads to the developmental toxicity of multiple tissues and organs in many ways. Regarding maternal-derived glucocorticoid-mediated IUGR, developmental programming, and susceptibility to multiple conditions after birth, ethanol induces programmed changes in the neuroendocrine axes of offspring, such as the hypothalamus-pituitary-adrenal (HPA) and glucocorticoid-insulin-like growth factor 1 (GC-IGF1) axes. In addition, the differences in ethanol metabolic enzymes, placental glucocorticoid barrier function, and the sensitivity to glucocorticoids in various tissues and organs mediate the severity and sex differences in the developmental toxicity of ethanol exposure during pregnancy. Offspring exposed to ethanol during pregnancy have a "thrifty phenotype" in the fetal period, and show "catch-up growth" in the case of abundant nutrition after birth; when encountering adverse environments, these offspring are more likely to develop diseases. Here, we review the developmental toxicity, functional alterations in multiple organs, and neuroendocrine metabolic programming mechanisms induced by PEE based on our research and that of other investigators. This should provide new perspectives for the effective prevention and treatment of ethanol developmental toxicity and the early prevention of related fetal-originated diseases.

Analysis of risk factors for advanced age in patients with frozen shoulder.

OBJECTIVE: To explore the risk factors of elderly patients with frozen shoulder. METHODS: 262 cases of scapulohumeral periarthritis treated in our hospital from January 2020 to December 2020 were analyzed retrospectively. According to the age of patients, patients younger than 60 years old were divided into middle-aged group (101 cases), patients between 60 and 75 years old were divided into old-aged group (91 cases), and patients ≥ 75 years old were divided into old-aged group (70 cases). The general demographic data and clinical data of the three groups were compared. Visual analogue scale (VAS) was used to evaluate the degree of pain. Finally, the dependent variable is set as whether the onset age of scapulohumeral periarthritis patients is advanced. Univariate and multivariate Logistic regression was used to analyze the risk factors of frozen shoulder patients at an advanced age. RESULTS: There were no significant differences in general demographic data, fixed position, hypertension history, smoking history, drinking history, supraspinatus muscular atrophy and physical exercise among the three groups (all P > 0.05). The course of disease, diabetes, surgical treatment, pain degree, operation time, cholecystitis, coronary heart disease, pain degree three months after operation and cervical spondylosis in the elderly group were all higher than those in the middle-aged group and the elderly group, and the differences were statistically significant (all P < 0.05). The course of scapulohumeral periarthritis, the degree of pain and the degree of pain 3 months after operation in the elderly group were higher than those in the middle-aged group, with significant differences (all P < 0.05). Univariate Logistic regression analysis showed that the risk factors of scapulohumeral periarthritis in the elderly included diabetes mellitus (OR = 3.067, 95% CI 1.881-4.587, P < 0.001), operative treatment (OR = 3.076, 95% CI 1.365-6.765, P = 0.006), VAS score (OR = 2.267, 95% CI 1.117-3.887, P = 0.013), operation time (OR = 1.537, 95% CI 1.305-2.579, P < 0.001), cholecystitis (OR = 2.143, 95% CI 1.019-4.876, P = 0.023), coronary heart disease(OR = 3.128, 95% CI 1.428-7.019, P = 0.005), VAS at 3 months after operation (OR = 1.537, 95% CI 0.786-2.635, P = 0.002), and cervical spondylosis(OR = 1.162, 95% CI 1.029-1.321, P = 0.012). Multivariate logistic regression analysis showed that the risk factors for the onset of the disease at advanced age included fatty infiltration (OR = 4.021, 95% CI 2.981-9.682, P < 0.001), surgical treatment (OR = 4.109, 95% CI 1.419-7.832, P = 0.008), VAS score (OR = 3.081, 95% CI 1.042-7.931, P = 0.046) and operation time (OR = 1.537, 95% CI 1.305-2.579, P < 0.001). CONCLUSION: Risk factors of frozen shoulder at advanced age include fat infiltration, surgical treatment, VAS score and surgical time. In clinical practice, we should refer to the above indicators to help patients with early medical intervention and prevent their onset.

The effects of tourniquet use on blood loss and perioperative complications in total knee arthroplasty.

BACKGROUND: There has been ongoing debate about the use of tourniquets in total knee arthroplasty, and their application is widely studied. A comprehensive understanding of the advantages and disadvantages of tourniquet use during the procedure is crucial for optimizing surgical outcomes. This study aimed to investigate the effectiveness of tourniquet application, with a particular focus on blood loss and perioperative complications, providing valuable insights for clinical practice. METHODS: Fifty patients who underwent total knee arthroplasty were randomized into tourniquet (n = 25) and nontourniquet (n = 25) groups. The same surgeon performed all surgical procedures. The follow-up time was 14 days after surgery. Primary outcomes were hemoglobin level changes, blood loss, operation time, and perioperative plasma D-dimer levels. Secondary outcomes were postoperative complications, including thrombotic and nonthrombotic events. RESULTS: No significant differences were found in drainage, calculated blood loss, total blood loss, postoperative hemoglobin levels, or blood transfusion between the two groups (P > 0.05). No differences in D-dimer levels were observed on postoperative Days 1, 3, and 14 between the two groups, except on postoperative Day 7, when the D-dimer level in the tourniquet group was lower than that in the nontourniquet group (P = 0.03). The incidence of local complications (thigh bruising, blisters, pain, fat liquefaction, and superficial infections) in the tourniquet group was significantly higher than that in the nontourniquet group (P = 0.03), but no significant differences were found in thromboembolic and nonthromboembolic events or overall complications (P > 0.05). CONCLUSION: We conclude that tourniquet use does not reduce the length of surgery or blood loss but does increase local complications in total knee arthroplasty.

Dendrobine Alleviates Cellular Senescence and Osteoarthritis via the ROS/NF-κB Axis.

Osteoarthritis (OA) is a degenerative joint disease characterized by low-grade inflammation and cartilage degradation. Dendrobine (DEN) is reported to inhibit inflammation and oxidative stress in some diseases, but its role in chondrocyte senescence and OA progress has not yet been elucidated. Our study aimed to explore the protective effects of DEN on OA both in vitro and in vivo. We found that DEN inhibited extracellular matrix (ECM) degradation and promoted ECM synthesis. Meanwhile, DEN inhibited senescence-associated secretory phenotype (SASP) factors expression and senescence phenotype in IL-1ß-treated chondrocytes. Furthermore, DEN improved mitochondrial function and reduced the production of intracellular reactive oxygen species (ROS). Also, DEN suppressed IL-1ß-induced activation of the NF-κB pathway. Further, using NAC (ROS inhibitor), we found that DEN might inhibit NF-κB cascades by reducing ROS. Additionally, X-ray, micro-CT, and histological analyses in vivo demonstrated that DEN significantly alleviated cartilage inflammation, ECM degradation, and subchondral alterations in OA progression. In conclusion, DEN inhibits SASP factors expression and senescence phenotype in chondrocytes and alleviated the progression of OA via the ROS/NF-κB axis, which provides innovative strategies for the treatment of OA.

Midterm outcomes of 18 patients with primary intra-articular diffuse tenosynovial giant cell tumor (TGCT) of the knee treated with complete arthroscopic synovectomy and postoperative low-dose radiotherapy at a mean follow-up of 68 months.

OBJECTIVE: To evaluate the long-term clinical outcome of the treatment of complete arthroscopic synovectomy combined with low-dose external radiotherapy in the knee affected by primary intra-articular diffuse tenosynovial giant cell tumor (TGCT). METHODS: From May 2009 to January 2016, 18 patients with intra-articular diffuse TGCT underwent complete arthroscopic synovectomy and low-dose external-beam radiotherapy in Zhongnan Hospital were enrolled in this retrospective study. The preoperative symptoms of patients, the complications during or after the arthroscopic procedure and the recurrence were collected and recorded. Each patient was evaluated before treatment and at the follow-up visit. Efficacy evaluation criteria were based on Ogilvie-Harris score, and the evaluation of the functional ability of knee was based on the International Knee Documentation Committee (IKDC) Score. RESULTS: The mean time from symptom onset to surgery was 9.1 ± 5.8 months (range from 3 to 29 months). The most frequent preoperative symptoms were joint effusion (100%), diffuse non-specific knee pain (66.7%), and a decreased range of motion (83.3%). Mean follow-up time was 68.0 ± 18.1 months (range from 35 to 120 months). The mean evaluation score according to the Ogilvie-Harris criteria before treatment was 3.19 ± 0.74, which corresponded to a rating of "poor". The mean score after treatment was 8.79 ± 1.57, rated as "good". The Ogilvie-Harris score was significantly increased after treatment (P = 0.003). The IKDC score of all patients increased significantly from 37.1 ± 3.8 before treatment to 83.9 ± 11.3 after treatment. The IKDC score was obviously increased after treatment (P = 0.001). No recurrence was noted at final follow-up. There were no complications during or after the arthroscopic procedure. CONCLUSION: The outcome of this study proved that complete arthroscopic synovectomy combined with low-dose external radiotherapy was appropriate for treating primary intra-articular diffuse TGCT of the knee joint. It could be safely and reliably used with minimal complications, fast postoperative recovery and satisfactory control of recurrence rates.

Dosage, Efficacy, and Safety of Intra-articular Vancomycin for Prophylaxis of Periprosthetic Joint Infection Caused by Methicillin-Resistant Staphylococcus aureus after Total Knee Arthroplasty in a Rat Model.

Although intra-articular vancomycin powder (VP) is sometimes applied before the closure of the incision to prevent periprosthetic joint infection (PJI) after joint replacement, the dosage, efficacy, and safety remain controversial. This study aimed to explore the dosage, efficacy, and safety of intra-articular VP in the prophylaxis of infection after total knee arthroplasty (TKA) in a rat model. Sixty male rats were randomly divided into five groups after receiving TKA: control (no antibiotics); systemic vancomycin (SV) (intraperitoneal injection, 88 mg/kg of body weight, equal to 1 g in a patient weighing 70 kg); and VP0.5, VP1.0, and VP2.0 (44 mg/kg, 88 mg/kg and 176 mg/kg, respectively; intra-articular). All animals were inoculated in the knee with methicillin-resistant S. aureus (MRSA). General status, serum biomarkers, radiology, microbiological assay, and histopathological tests were assessed within 14 days postoperation. Compared with the control and SV groups, bacterial counts, knee width, tissue inflammation, and osteolysis were reduced in the VP0.5, VP1.0, and VP2.0 groups, without notable body weight loss and incision complications. Among all the VP groups, VP1.0 and VP2.0 groups presented superior outcomes with regard to knee width and tissue inflammation than the VP0.5 group. Microbial culture indicated that no MRSA survived in the knee of VP1.0 and VP2.0 groups, while bacteria growth was observed in the VP0.5 group. No obvious changes in the structure and functional biomarkers of liver and kidney were observed in either the SV or VP groups. Therefore, intra-articular vancomycin powder at a dosage from 88 mg/kg to 176 mg/kg may be effective and safe in preventing PJI induced by methicillin-resistant S. aureus in the rat TKA model.

Evaluation of Experimental and Clinical Efficacy on Surgical Debridement and Systemic Antibiotics Treatment for Early Knee Infection after Anterior Cruciate Ligament Reconstruction.

Deep knee infection (DKI) after anterior cruciate ligament reconstruction (ACLR) is rare and challenging. The optimal treatment strategy for infection after ACLR remains controversial. This study aimed to investigate the optimal treatment for early infection after ACLR surgery. Rats with unilateral ACLR were injected with 3.0 × 105 colony forming units (CFU) of Staphylococcus aureus in the knee joint for 7 days. Next, with surgical debridement (SD) and/or 21 days of antimicrobial (systemic vancomycin and oral rifampicin [SVR]) therapy, rats were euthanatized and samples harvested. We evaluated signs of infection by general postoperative conditions, serum inflammatory markers, microbiological counting, knee radiographs, micro-computed tomography (micro-CT), histologic staining, and scanning electron microscopy (SEM). Clinically, the data from 12 patients who suffered from DKI after ACLR were analyzed retrospectively. The DKI rats treated with SVR showed better outcomes in general postoperative conditions, serum inflammatory markers, microbiological counting, biofilm on the interference screw and graft, radiographic signs of periarticular osseous destruction, and inflammatory reaction in the joint tissues than those with SD treatment, while the DKI rats with SD and SVR administration showed the best outcomes. Rats which received SD and SVR administration had their S. aureus contamination completely eradicated. All patients treated with SD & SVR or SVR alone had effectively controlled knee infections and achieved good knee function outcomes in the 6 months after treatment, but one patient developed more serious knee infections. Therefore, surgical debridement combined with systemic antibiotics treatment could effectively eliminate S. aureus contamination in the DKI rat model and in patients after ACLR without affecting knee function. Treatment with systemic antibiotics could also control early DKI, which would be especially applicable in patients who could not tolerate surgery.

Prenatal caffeine exposure caused H-type blood vessel-related long bone dysplasia via miR375/CTGF signaling.

Caffeine has developmental toxicity. Prenatal caffeine exposure (PCE) caused intrauterine growth retardation (IUGR) and multiple organ dysplasia. This study intended to explore the effect and mechanism of PCE on long bone development in female fetal rats. In vivo, the PCE group pregnant rats were given different concentrations of caffeine during the gestational Day 9-20. The mRNA expression of osteogenesis-related genes were significantly reduced in PCE group. In the PCE group (120 mg/kg·d), the length and primary center of fetal femur were shorter, and accompanied by H-type blood vessel abundance reducing. Meanwhile, connective tissue growth factor (CTGF) expression decreased in the growth plate of the PCE group (120 mg/kg·d). In contrast, the miR375 expression increased. In vitro, caffeine decreased CTGF and increased miR375 expression in fetal growth plate chondrocytes. After co-culture with caffeine-treated chondrocytes, the tube formation ability for the H-type endothelial cells was decreased. Furthermore, CTGF overexpression or miR375 inhibitor reversed caffeine-induced reduction of tube formation ability, and miR375 inhibitor reversed caffeine-induced CTGF expression inhibition. In summary, PCE decreased the expression of CTGF by miR375, ultimately resulting in H-type blood vessel-related long bone dysplasia.

11ß-Hydroxysteroid dehydrogenase 2: A key mediator of high susceptibility to osteoporosis in offspring after prenatal dexamethasone exposure.

Epidemiological investigations have shown that individuals treated with dexamethasone during pregnancy have an increased risk of osteoporosis after birth. Our studies reported that peak bone mass was decreased in the prenatal dexamethasone exposure (PDE) offspring before chronic stress, while further decrease was observed after chronic stress. Simultaneously, increase of bone local active corticosterone was observed in the PDE offspring, while further increase was also observed after chronic stress. Moreover, the histone H3 lysine 9 acetylation (H3K9ac) level of 11-beta hydroxysteroid dehydrogenase 2 (11ß-HSD2) and its expression in bone tissue of PDE offspring rats remained lower than the control before and after birth. Injection of 11ß-HSD2 overexpression lentivirus into the bone marrow cavity could partially alleviate the accumulation of bone local active corticosterone and bone loss induced by PDE. In vitro, dexamethasone inhibited the expression of 11ß-HSD2 and aggravated the inhibitory effect of corticosterone on the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Overexpression of 11ß-HSD2 partially alleviated the inhibitory effect of corticosterone. Moreover, dexamethasone promoted the nuclear translocation of glucocorticoid receptor (GR), which resulted in the stimulation of 11ß-HSD2 expression due to the binding of GR to the 11ß-HSD2 promoter region directly, as well as increasing H3K9ac level in the 11ß-HSD2 promoter region by recruiting histone deacetylase 11 (HDAC11). Our results indicated that low expression of 11ß-HSD2 in bone tissue is an important mediator for the high susceptibility to osteoporosis in PDE adult offspring.

Programming changes of hippocampal miR-134-5p/SOX2 signal mediate the susceptibility to depression in prenatal dexamethasone-exposed female offspring.

Depression is a neuropsychiatric disorder and has intrauterine developmental origins. This study aimed to confirm the depression susceptibility in offspring rats induced by prenatal dexamethasone exposure (PDE) and to further explore the intrauterine programming mechanism. Wistar rats were injected with dexamethasone (0.2 mg/kg·d) subcutaneously during the gestational days 9-20 and part of the offspring was given chronic stress at postnatal weeks 10-12. Behavioral results showed that the adult PDE female offspring was susceptible to depression, accompanied by increased hippocampal miR-134-5p expression and decreased sex-determining region Y-box 2 (SOX2) expression, as well as disorders of neural progenitor cells proliferation and hippocampal neurogenesis. The PDE female fetal rats presented consistent changes with the adult offspring, accompanied by the upregulation of glucocorticoid receptor (GR) expression and decreased sirtuin 1 (SIRT1) expression. We further found that the H3K9ac level of the miR-134-5p promoter was significantly increased in the PDE fetal hippocampus, as well as in adult offspring before and after chronic stress. In vitro, the changes of GR/SIRT1/miR-134-5p/SOX2 signal by dexamethasone were consistent with in vivo experiments, which could be reversed by GR receptor antagonist, SIRT1 agonist, and miR-134-5p inhibitor. This study confirmed that PDE led to an increased expression level as well as H3K9ac level of miR-134-5p by activating the GR/SIRT1 pathway in the fetal hippocampus and then inhibited the SOX2 expression. The programming effect mediated by the abnormal epigenetic modification could last from intrauterine to adulthood, which constitutes the intrauterine programming mechanism leading to hippocampal neurogenesis disorders and depression susceptibility in female offspring. Intrauterine programming mechanism for the increased depressive susceptibility in adult female offspring by prenatal dexamethasone exposure (PDE). GR, glucocorticoid receptor; SIRT1, sirtuin 1; SOX2, sex-determining region Y-box 2; NPCs, neuroprogenitor cells; H3K9ac, histone 3 lysine 9 acetylation; GRE, glucocorticoid response element.

Intrauterine programming of cartilaginous 11ß-HSD2 induced by corticosterone and caffeine mediated susceptibility to adult osteoarthritis.

Our previous study reported that prenatal caffeine exposure (PCE) could induce chondrodysplasia and increase the susceptibility to osteoarthritis in offspring rats. However, the potential mechanisms and initiating factors remain unknown. This study aims to investigate whether 11ß-HSD2, a glucocorticoid-metabolizing enzyme, is involved in the susceptibility of osteoarthritis induced by PCE and to further explore its potential mechanisms and initiating factors. Firstly, we found that PCE reduced cartilage matrix synthesis (aggrecan/Col2a1 expression) in male adult offspring rats and exhibited an osteoarthritis phenotype following chronic stress, which was associated with persistently reduced H3K9ac and H3K27ac levels at the promoter of 11ß-HSD2 as well as its expression in the cartilage from fetus to adulthood. The expression of 11ß-HSD2, aggrecan and Col2a1 were all decreased by corticosterone in the fetal chondrocytes, while overexpression of 11ß-HSD2 could partially alleviate the decrease of matrix synthesis induced by corticosterone in vitro. Furthermore, the glucocorticoid receptor (GR) activated by glucocorticoids directly bonded to the promoter region of 11ß-HSD2 to inhibit its expression. Meanwhile, the activated GR reduced the H3K9ac and H3K27ac levels of 11ß-HSD2 by recruiting HDAC4 and promoting GR-HDAC4 protein interaction to inhibit the 11ß-HSD2 expression. Moreover, caffeine could reduce the expression of 11ß-HSD2 by inhibiting the cAMP/PKA signaling pathway but without reducing the H3K9ac and H3K27ac levels of 11ß-HSD2, thereby synergistically enhancing the corticosterone effect. In conclusion, the persistently reduced H3K9ac and H3K27ac levels of 11ß-HSD2 from fetus to adulthood mediated the inhibition of cartilage matrix synthesis and the increased susceptibility to osteoarthritis. This epigenetic programming change in utero was induced by glucocorticoids with synergistic effect of caffeine.

Autologous Dedifferentiated Osteogenic Bone Marrow Mesenchymal Stem Cells Promote Bone Formation in a Rabbit Model of Anterior Cruciate Ligament Reconstruction versus Bone Marrow Mesenchymal Stem Cells.

PURPOSE: This study aimed to verify whether transplantation of dedifferentiated osteogenic bone marrow mesenchymal stem cells (De-BMSCs) at the tendon-bone interface could result in more bone formation than BMSC transplantation in anterior cruciate ligament (ACL) reconstruction. METHODS: BMSCs from femur and tibia of New Zealand White rabbit were subjected to osteogenic induction and then cultured in osteogenic factor-free medium; the obtained cell population was termed De-BMSCs. Bilateral ACL reconstruction was performed in 48 adult rabbits. Three groups were established: control group with alginate gel injection, BMSCs group with the BMSCs injection, and De-BMSCs group with the De-BMSCs injection. At week 4 and 12 postoperatively, tendon-bone healing by histologic staining, micro-computed tomography examination, and biomechanical test were evaluated. RESULTS: The expression of α1 chain of type I collagen, osteocalcin, and osteopontin at the tendon-bone interface in the De-BMSCs group was greater than in the control or BMSCs group. The bone volume/total volume by micro-computed tomography scan was significantly greater in the De-BMSCs group than that in the control group (P = .013) or BMSCs group (P = .045) at 4 weeks, and greater than that in the control group (P = .014) or BMSCs group (P = .017) at 12 weeks. The tunnel area was significantly smaller in the De-BMSCs group than in the control group (P = .013) or BMSCs group (P = .044) at 12 weeks. The failure load and stiffness in De-BMSCs group were both significantly enhanced at 4 and 12 weeks than control group or De-BMSCs group. CONCLUSIONS: De-BMSCs transplantation can promote bone formation at the tendon-bone interface better than BMSCs transplantation in ACL reconstruction and increase the early biomechanical strength of the reconstructed ACL CLINICAL RELEVANCE: De-BMSCs transplantation is a potential choice for enhancing early bone formation in the tunnel in ACL reconstruction.