Reduction of intraarticular adhesion by topical application of colchicine following knee surgery in rabbits

Computational screening of biomarkers and potential drugs for arthrofibrosis based on combination of sequencing and large nature language model

Background

Arthrofibrosis (AF) is a fibrotic joint disease resulting from excessive collagen production and fibrous scar formation after total knee arthroplasty (TKA). This devastating complication may cause consistent pain and dramatically reduction of functionality. Unfortunately, the conservative treatments to prevent the AF in the early stage are largely unknown due to the lack of specific biomarkers and reliable therapeutic targets.

Methods

In this study, we extracted1782 fibrosis related genes (FRGs) from 373,461published literature based on the large natural language processing models (ChatGPT) and intersected with the 2750 differential expressed genes (DEGs) from mRNA microarray (GSE135854). A total of 311 potential AF biomarker genes (PABGs) were obtained and functional analysis were performed including gene ontology (GO) annotation and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Subsequently, we accomplished validation in AF animal models with immobilization of the unilateral knee joints of 16 rabbits for 1-week, 2-weeks, 3-weeks and 4-weeks. Finally, we tested the biomarkers in a retrospective cohort enrolled 35 AF patients and 35 control group patients.

Results

We identified G-protein-coupled receptor 17 (GPR17) as a reliable therapeutic biomarker for AF diagnosis with higher AUC (0.819) in the ROC curve. A total of 21 potential drugs targeted to GPR17 were screened. Among them, pranlukast and montelukast have achieved therapeutic effect in animal models. In addition, we established an online AF database for data integration (https://chenxi2023.shinyapps.io/afdbv1).

Conclusions

These results unveiling therapeutic biomarkers for AF diagnosis, and provide potential drugs for clinical treatment.

The translational potential of this article

Our study demonstrated that GPR17 holds significant promise as a potential biomarker and therapeutic target for arthrofibrosis. Moreover, pranlukast and montelukast targeted to GPR17 that could be instrumental in the treatment of AF.

Single-cell and bulk tissue sequencing unravels the heterogeneity of synovial microenvironment in arthrofibrosis

Arthrofibrosis (AF) is a debilitating complication that occurs after trauma or surgery, leading to functional impairment and surgical failures worldwide. This study aimed to uncover the underlying mechanism of AF. A total of 141 patients were enrolled, and synovial samples were collected from both patients and animal models at different time points. Single-cell RNA-sequencing (scRNA-seq) and bulk tissue RNA sequencing (bulk-seq) were employed to profile the distinct synovial microenvironment. This study revealed changes in cell proportions during AF pathogenesis and identified Engrailed-1 (EN1) as a key transcription factor strongly associated with disease severity and clinical prognosis. Additionally, the researchers discovered a specific type of synovial fibroblast called DKK3-SLF, which played a critical role in driving AF development. These findings shed light on the composition and heterogeneity of the synovial microenvironment in AF, offering potential avenues for identifying therapeutic targets and developing clinical treatments for AF and other fibrotic diseases.

Comparison of the preventive effect of colchicine versus diphenhydramine, prednisolone, and a combination therapy on intraperitoneal adhesion bands: an experimental study in rats

BACKGROUND

Peritoneal adhesion formation is an inevitable consequence of abnormal repair of the peritoneum following different peritoneal injuries of intra-abdominal operations with the subsequent morbidity that they represent. Vast efforts have been made to elucidate the cause and prevent the development of abdominal adhesions. The aim of our study is to compare the capability of colchicine versus diphenhydramine (DPH) and methylprednisolone (MP), and also prednisolone in adhesion prevention.

METHODS

Sixty-one male Wistar stock rats were divided into four groups. The first group attended as the control group. Groups 2, 3, and 4 received oral combination of MP + DPH solution (20 mg/kg), colchicine (0.02 mg/kg), and prednisolone (1 mg/ kg), respectively. Adhesion bands were induced by standardized abrasion of the peritoneum through a midline laparotomy. All rats were sacrificed on the 15^th-day post medication administration and the subjects underwent an exploratory laparotomy. The presence of adhesions was evaluated with the modified using Nair's classification.

RESULTS

The proportion of the control group with substantial adhesion bands (73.3%) was significantly higher than that of the MP + DPH (13.3%), colchicine (33.3%), and prednisolone (31.3%) groups. There were significant differences between the scores of the control and the MP + DPH, colchicine, and prednisolone groups (P = 0.001, 0.028, and 0.019, respectively). There was no statistically significant difference to favor colchicine against MP + DPH (P = 0.390) or MP + DPH against prednisolone (P = 0.394).

CONCLUSIONS

Both colchicine and combination of DPH + MP prevented postoperative abdominal adhesions separately in our study. However, the lowest adhesion formation rate was observed in the DPH + MP group, even lower than the prednisolone group.

Cell Type-Specific Anti-Adhesion Properties of Peritoneal Cell Treatment with Plasma-Activated Media (PAM)

Postoperative abdominal adhesions are responsible for serious clinical disorders. Administration of plasma-activated media (PAM) to cell type-specific modulated proliferation and protein biosynthesis is a promising therapeutic strategy to prevent pathological cell responses in the context of wound healing disorders. We analyzed PAM as a therapeutic option based on cell type-specific anti-adhesive responses. Primary human peritoneal fibroblasts and mesothelial cells were isolated, characterized and exposed to different PAM dosages. Cell type-specific PAM effects on different cell components were identified by contact- and marker-independent Raman imaging, followed by thorough validation by specific molecular biological methods. The investigation revealed cell type-specific molecular responses after PAM treatment, including significant cell growth retardation in peritoneal fibroblasts due to transient DNA damage, cell cycle arrest and apoptosis. We identified a therapeutic dose window wherein specifically pro-adhesive peritoneal fibroblasts were targeted, whereas peritoneal mesothelial cells retained their anti-adhesive potential of epithelial wound closure. Finally, we demonstrate that PAM treatment of peritoneal fibroblasts reduced the expression and secretion of pro-adhesive cytokines and extracellular matrix proteins. Altogether, we provide insights into biochemical PAM mechanisms which lead to cell type-specific pro-therapeutic cell responses. This may open the door for the prevention of pro-adhesive clinical disorders.

Identification of novel biomarkers for arthrofibrosis after total knee arthroplasty in animal models and clinical patients

Background

Arthrofibrosis is a debilitating complication after total knee arthroplasty (TKA) which becomes a considerable burden for both patients and clinical practitioners. Our study aimed to identify novel biomarkers and therapeutic targets for drug discovery.

Methods

Potential biomarker genes were identified based on bioinformatic analysis. Twelve male New Zealand white rabbits underwent surgical fixation of unilateral knees to mimics the joint immobilization of the clinical scenario after TKA surgery. Macroscopic assessment, hydroxyproline content determination, and histological analysis of tissue were performed separately after 3-days, 1-week, 2-weeks, and 4-weeks of fixation. We also enrolled 46 arthrofibrosis patients and 92 controls to test the biomarkers. Clinical information such as sex, age, range of motion (ROM), and visual analogue scale (VAS) was collected by experienced surgeons

Findings

Base on bioinformatic analysis, transforming growth factor-beta receptor 1 (TGFBR1) was identified as the potential biomarkers. The level of TGFBR1 was significantly raised in the rabbit synovial tissue after 4-weeks of fixation (p<0.05). TGFBR1 also displayed a highly positive correlation with ROM loss and hydroxyproline contents in the animal model. TGFBR1 showed a significantly higher expression level in arthrofibrosis patients with a receiver operating characteristic (ROC) area under curve (AUC) of 0.838. TGFBR1 also performed positive correlations with VAS baseline (0.83) and VAS after 1 year (0.76) while negatively correlated with ROM baseline (-0.76) in clinical patients.

Interpretation

Our findings provided novel biomarkers for arthrofibrosis diagnosis and uncovered the role of TGFBR1. This may contribute to arthrofibrosis prevention and therapeutic drug discovery.

Overexpression of laminin α4 facilitates proliferation and migration of fibroblasts in knee arthrofibrosis by targeting canonical Shh/Gli1 signaling

Aim: Pathologic hyperplasia of fibroblast is responsible for the progression of intraarticular fibrosis. Laminin α4 (LAMA4), a subunit of laminin macromolecule family, was found to be overexpressed in various fibrotic tissues. However, the role of LAMA4 in knee arthrofibrosis remains elusive. Therefore, the aim of this study was to investigate the effect and mechanism of LAMA4 on fibroblast proliferation and migration. Materials and methods: Following knee surgery, LAMA4 expression was detected in intraarticular fibrous tissues in rabbits at week 2 and week 4, respectively. In lentivirus-mediated LAMA4-overexpressed fibroblasts, cellular proliferation was assessed by EdU labeling and cell cycle analysis, cellular migration was evaluated using Transwell assay, and the expressions of key components in Shh/Gli1 signaling were detected by qRT-PCR, western blot and immunofluorescence analysis. Additionally, canonical Shh cascade was further blocked in LAMA4-overexpressed fibroblasts by cyclopamine, and the changes in cellular proliferation and migration were investigated. Results: LAMA4 expression was positively correlated with the severity of knee arthrofibrosis. Functional studies demonstrated that LAMA4 overexpression facilitated proliferation, cell cycle progression and migration in fibroblasts. Mechanically, LAMA4 activated the canonical Shh/Gli1 signaling and promoted the nuclear translocation of Gli1 to upregulate expression of genes associated with cellular proliferation and migration. Intriguingly, blockage of Shh/Gli1 signaling with cyclopamine reversed the promoting effects of LAMA4 on proliferation and migration of fibroblasts. Conclusions: LAMA4 positively regulated cellular proliferation and migration in fibroblasts via activating the Shh/Gli1 signaling. LAMA4/Shh/Gli1 signaling axis might be a potential therapeutic target for the prevention of surgery-induced intraarticular fibrosis.

The Prognosis of Arthrofibroses: Prevalence, Clinical Shortcomings, and Future Prospects

Fibrosis is the dysregulated biosynthesis of connective tissue that results from persistent infection, high serum cholesterol, surgery, trauma, or prolonged joint immobilization. As a disease that impacts connective tissue, it is prevalent across the body and disrupts normal extracellular and tissue organization. Ultimately, fibrosis impairs the tissue structural, mechanical, or biochemical function. This review describes the clinical landscape of joint fibrosis, that is, arthrofibrosis, including the risk factors and causes, as well as current clinical treatments and their shortcomings. Because treating arthrofibrosis remains an unmet clinical challenge, we present several animal models used for exploration of the physiopathology of arthrofibrosis and summarize their use for testing novel treatments. We then discuss therapeutics for the prevention or treatment of arthrofibrosis that are in preclinical development and in ongoing clinical trials. We conclude with recent findings from molecular biological studies of arthrofibroses that shed insight on future areas of research for improved treatments.

Homoharringtonine inhibits fibroblasts proliferation, extracellular matrix production and reduces surgery-induced knee arthrofibrosis via PI3K/AKT/mTOR pathway-mediated apoptosis

Background

The prevention of surgery-induced intraarticular fibrosis remains a challenge following orthopedic surgery. Homoharringtonine (HHT) has been reported to have positive effects in preventing various kinds of fibrosis. However, little is known regarding its effect as well as the potential mechanism of HHT in preventing surgery-induced intraarticular fibrosis.

Methods

Various concentrations of HHTs were locally applied in vivo to reduce knee intraarticular fibrosis in rabbits. Histological macroscopic assessments such as hematoxylin and eosin (HE) staining, Masson’s trichrome staining, and Picric-sirius red polarized light were used to evaluate the effect of HHT in reducing intraarticular fibrosis. CCK-8, cell cycle assay, and EdU incorporation assay were used in vitro to detect HHT’s effect on inhibiting fibroblast viability and proliferation. The effect of HHT on fibroblast differentiation, extracellular matrix production, and apoptosis were evaluated by western blot, flow cytometry, immunofluorescent staining, and TUNEL analysis. Moreover, the expressions of PI3K/AKT/mTOR signaling pathway were detected.

Results

The results demonstrated that HHT could reduce the formation of intraarticular fibrosis. HHT was also found to induce fibroblast apoptotic cell death in a dose- and time-dependent manner in vitro. Moreover, HHT could effectively inhibit the production of the extracellular matrix secreted by fibroblasts and inhibited the expression of p-PI3K, p-AKT, and p-mTOR in a dose-dependent manner. After treating with insulin-like growth factor-1 (IGF-1), an activator of the PI3K/AKT axis, the expressions of pro-apoptosis-related proteins were decreased, and the fibroblast apoptosis rate was also inhibited.

Conclusions

In conclusion, this study demonstrated that HHT could reduce the formation of intraarticular fibrosis through the inhibition of fibroblast proliferation, extracellular matrix production, and the induction of fibroblast apoptotic cell death. Furthermore, its potential mechanism may be through the suppression of the PI3K/AKT/mTOR signaling pathway.

Mechanisms involved in the arthrofibrosis formation and treatments following bone fracture

Arthrofibrosis is a common complication for patients with bone fracture following external and internal fixation. In this review, we summarize the related factors and significant pathways for joint adhesion following fracture surgery. Moreover, the different types of treatments and related preventive measures are also discussed. Many factors related to the development and treatment of arthrofibrosis are discussed in this review in order to provide possible clues for the prospective targets to develop new medication or treatments for preventing or reducing the joint adhesion following orthopedic surgery.

Prospective application of stem cells to prevent post-operative skeletal fibrosis

Post-operative skeletal fibrosis is considered one of the major complications causing dysfunction of the skeletal system and compromising the outcomes of clinical treatment. Limited success has been achieved using current therapies; more effective therapies to reduce post-operative skeletal fibrosis are needed. Stem cells possess the ability to repair and regenerate damaged tissue. Numerous studies show that stem cells serve as a promising therapeutic approach for fibrotic diseases in tissues other than the skeletal system by inhibiting the inflammatory response and secreting favorable cytokines through activating specific signaling pathways, acting as so-called medicinal signaling cells. In this review, current therapies are summarized for post-operative skeletal fibrosis. Given that stem cells are used as a promising therapeutic approach for fibrotic diseases, little effort has been undertaken to use stem cells to prevent post-operative skeletal fibrosis. This review aims at providing useful information for the potential application of stem cells in preventing post-operative skeletal fibrosis in the near future. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1236-1245, 2019.

Upregulation of NOXA by 10-Hydroxycamptothecin plays a key role in inducing fibroblasts apoptosis and reducing epidural fibrosis

The fibrosis that develops following laminectomy or discectomy often causes serious complications, and the proliferation of fibroblasts is thought to be the major cause of epidural fibrosis. 10-Hydroxycamptothecin (HCPT) has been proven to be efficient in preventing epidural fibrosis, but the exact mechanism is still unclear. NOXA is a significant regulator of cell apoptosis, which has been reported to be beneficial in the treatment of fibrosis. We performed a series of experiments, both in vitro and in vivo, to explore the intrinsic mechanism of HCPT that underlies the induction of apoptosis in fibroblasts, and also to investigate whether HCPT has positive effects on epidural fibrosis following laminectomy in rats. Fibroblasts were cultured in vitro and stimulated by varying concentrations of HCPT (0, 1, 2, 4 µg/ml) for various durations (0, 24, 48, 72 h); the effect of HCPT in inducing the apoptosis of fibroblasts was investigated via Western blots and TUNEL assay. Our results showed that HCPT could induce apoptosis in fibroblasts and up-regulate the expression of NOXA. Following the knockdown of NOXA in fibroblasts, the results of Western blot analysis showed that the level of apoptotic markers, such as cleaved-PARP and Bax, was decreased. The results from the TUNEL assay also showed a decreased rate of apoptosis in NOXA-knocked down fibroblasts. For the in vivo studies, we performed a laminectomy at the L1-L2 levels in rats and applied HCPT of different concentrations (0.2, 0.1, 0.05 mg/ml and saline) locally; the macroscopic histological assessment, hydroxyproline content analysis and histological staining were performed to evaluate the effect of HCPT on reducing epidural fibrosis. The TUNEL assay in epidural tissues showed that HCPT could obviously induce apoptosis in fibroblasts in a dose-dependent manner. Also, immunohistochemical staining showed that the expression of NOXA increased as the concentrations of HCPT increased. Our findings are the first to demonstrate that upregulation of NOXA by HCPT plays a key role in inducing fibroblast apoptosis and in reducing epidural fibrosis. These findings might provide a potential therapeutic target for preventing epidural fibrosis following laminectomy.

Reduction of intraarticular adhesion of knee by local application of rapamycin in rabbits via inhibition of fibroblast proliferation and collagen synthesis

BACKGROUND

The formation of intraarticular adhesion is a common complication after total knee arthroplasty or anterior cruciate ligament reconstruction. Previously, little research was reported regarding whether the local application of rapamycin (RAPA) could reduce intraarticular adhesion following knee surgery. In our present study, we determined the therapeutic effect of RAPA by local application on the reduction of intraarticular adhesion following knee surgery in rabbits.

METHODS

In this study, we built the model of knee surgery according to a previous study. The decorticated areas of the cortical bone were exposed and covered with cotton pads soaked with different concentrations of RAPA or physiological saline for 10 min. All of the rabbits were euthanized 4 weeks after the surgery. Macroscopic evaluation of the hydroxyproline content, the histological morphological analysis and collagen density and fibroblast density were used to evaluate the effect of RAPA on reducing intraarticular adhesion.

RESULTS

The results shown that RAPA could significantly inhibit the proliferation of fibroblasts and reduce collagen synthesis; in the rabbit model of knee surgery, there were weak scar tissues around the decorticated areas in the 0.2 mg/ml RAPA group; moderate scar tissues were found in the 0.1 mg/ml RAPA group. However, severe fibrous adhesions were found in the 0.05 mg/ml RAPA group and the control group. The hydroxyproline content and the fibroblast density in the 0.2 mg/ml and 0.1 mg/ml RAPA groups were significantly less than those of the control group.

CONCLUSIONS

We concluded that the local application of RAPA could reduce intraarticular adhesion after knee surgery in the rabbit model; this effect was mediated by inhibition of fibroblast proliferation and collagen synthesis, which may provide a new method for reducing intraarticular adhesion after clinical knee surgery.

All-trans retinoic Acid reduces joint adhesion formation: an experimental study in rats

Background

Intra-articular adhesion is a common complication in post-surgical knees. The formation of post-surgical joint adhesion could lead to serious conditions. All-trans retinoic acid (ATRA) is a physiological metabolite of vitamin A that has a wide range of biological activities. The aim of the study was to verify the effects of (ATRA) in preventing adhesions in the post-operative rat knee.

Material/Methods

Eighty healthy adult male Wistar rats underwent femoral condyle-exposing surgery. After surgery, cotton pads soaked with the vehicle or various concentrations of ATRA (0.1%, 0.05%, 0.025%) were applied to the surgery site for 5 min. The post-surgical knee joints were fixed with micro-Kirschner wires in a flexed position for 4 weeks. The rats were killed 4 weeks after surgery. The effect of ATRA on the prevention of intra-articular adhesion was evaluated using histological analyses, hydroxyproline content, visual score, and inflammatory factor activity evaluation.

Results

No obvious postoperative complications or signs of infection in the rats were observed. None of the rats died before the scheduled time. The rats in the 0.1% ATRA group showed better outcomes, as suggested by the visual scores, hydroxyproline contents, and inflammatory factors expressional levels, than the other 2 groups. The local application of 0.1% ATRA was able to suppress adhesions, collagen expression, and inflammatory activity in the post-surgical rat knees.

Conclusions

In the rat knee surgery model, the application of intra-articular ATRA was able to decrease intra-articular scar adhesion formation, collagen expression, and inflammatory activities. ATRA was found to work in a dose-dependent manner, with 0.1% being possible optimal concentration.