Platelet-rich plasma attenuates the severity of joint capsule fibrosis following post-traumatic joint contracture in rats

The Effect of Platelet-Rich Plasma on Synovial Fibrosis and Cartilage Degeneration in Knee Osteoarthritis

BACKGROUND

Synovial fibrosis is a prevalent pathological feature of osteoarthritis and a primary contributor to joint pain and stiffness. Studies indicate that platelet-rich plasma (PRP) is rich in growth factors and cytokines, exhibiting anti-inflammatory, anti-apoptotic, chemotactic, and proliferative properties that can facilitate tissue repair. However, little is known about its effect on synovial fibrosis in knee osteoarthritis (KOA).

PURPOSE

To determine the effect of PRP on synovial fibrosis and cartilage degeneration in KOA.

STUDY DESIGN

Controlled laboratory study.

METHOD

Anterior cruciate ligament transection was performed to induce KOA in male Sprague-Dawley rats, and then rats were randomly assigned to 4 different groups: sham operation, KOA only, KOA treated with phosphate-buffered saline (PBS), and KOA treated with PRP. Synovial collagen fiber deposition was observed using Masson and Sirius red staining, and synovial inflammation was assessed using hematoxylin and eosin (H&E) staining. Moreover, immunohistochemistry was conducted to analyze the expression of synovial fibrosis-related factors including PLOD2, COL1A1, TIMP1, TGF-β1, and α-SMA. KOA severity and articular cartilage degradation were assessed using micro-computed tomography (micro-CT), safranin O-fast green staining, H&E staining, immunohistochemistry, and the Osteoarthritis Research Society International (OARSI) criteria. A quantitative analysis of growth factors (platelet-derived growth factor, IGF-1, epidermal growth factor, TGF-β1, fibroblast growth factor, and endothelial growth factor) in activated PRP was performed using enzyme-linked immunosorbent assay.

RESULTS

Micro-CT imaging and histological staining showed that the KOA model had been successfully established. Compared with the KOA and PBS groups, Masson staining and Sirius red staining results showed that PRP aggravated the degree of synovial fibrosis, which was consistent with the results of immunohistochemistry analysis. Immunohistochemistry analysis showed that PRP promoted the protein expression of PLOD2, COL1A1, TIMP1, TGF-β1, and α-SMA, indicating that the degree of fibrosis was aggravated. However, the PRP group showed lower OARSI and synovitis scores, as well as attenuated abnormal tibial subchondral bone remodeling, suggesting that PRP inhibited further cartilage degeneration and synovial inflammation and improved the subchondral bone microarchitecture.

CONCLUSION

PRP may aggravate KOA synovial fibrosis, but it still has an inhibitory effect on cartilage degeneration and abnormal subchondral bone remodeling.

CLINICAL RELEVANCE

Synovial fibrosis is a significant pathological feature in KOA that is closely linked to clinical symptoms like joint pain and stiffness. This study offers insights into enhancing the effectiveness of PRP therapy for patients with KOA.

The role of macrophages in hypertrophic scarring: molecular to therapeutic insights

Hypertrophic Scar (HS) is a common fibrotic disease of the skin, usually caused by injury to the deep dermis due to trauma, burns, or surgical injury. The main feature of HS is the thickening and hardening of the skin, often accompanied by itching and pain, which seriously affects the patient's quality of life. Macrophages are involved in all stages of HS genesis through phenotypic changes. M1-type macrophages primarily function in the early inflammatory phase by secreting pro-inflammatory factors, while M2-type macrophages actively contribute to tissue repair and fibrosis. Despite advances in understanding HS pathogenesis, the precise mechanisms linking macrophage phenotypic changes to fibrosis remain incompletely elucidated. This review addresses these gaps by discussing the pathological mechanisms of HS formation, the phenotypic changes of macrophages at different stages of HS formation, and the pathways through which macrophages influence HS progression. Furthermore, emerging technologies for HS treatment and novel therapeutic strategies targeting macrophages are highlighted, offering potential avenues for improved prevention and treatment of HS.

Anti-fibrosis effect and its mechanism of atractylenolide III on post-traumatic extending knee joint contracture in rats

OBJECTIVES

Atractylenolide III (ATL III) is the major bioactive component found in Atractylodes macrocephala, which has shown a range of benefits in pharmacological studies, including neuroprotection, anti-neuroinflammatory properties, antioxidant effects, anti-allergic effects, anti-cancer properties and antifibrotic abilities. Here, we investigated the therapeutic potential and underlying mechanisms of ATL III in the treatment of post-traumatic joint contracture (PTJC) in rat knees.

METHODS

The rat PTJC model and TGF-β1-induced a primary synovial fibroblast model were used to observe several fibrotic markers (α-SMA、TGF-β1、FGF2、COL1A1and COL3A1) using histological staining, immunofluorescence and western blot. Additionally, the effects of ATL III on synovial fibroblasts in vitro were evaluated through CCK-8 assays and migration assays to ascertain both cell viability and migratory behaviors. Furthermore, molecular docking studies were performed to elucidate the potential binding affinity of ATL III for Silent information regulator of transcription 1 (Sirt1), thereby providing insights into the underlying molecular mechanisms implicated in fibrosis modulation.

RESULTS

ATL III treatment was observed to reduce proliferating cells, inflammatory cells and collagen accumulation in a rat model of traumatic rat knee fibrosis. In vitro, ATL III treatment was found to significantly reduce fibrosis and collagen-associated protein expression and inhibit synovial fibroblast proliferation and migration. Molecular docking identified Sirt1 as a potential target of ATL III. Interestingly, Sirt1 and Smad3 can interact and act to deacetylate Smad3, and in vitro and in vivo ATL III treatment significantly reduced Smad3 acetylation levels.

CONCLUSION

ATL III produces a therapeutic effect on knee fibrosis probably because Sirt1 deacetylates Smad3 and thus relieves knee fibrosis in rats.

Novel Clinical Insights into the Pathogenesis of Posttraumatic Elbow Stiffness: An Expression Profile Analysis of Contracted Joint Capsule in Human

Background

Posttraumatic elbow stiffness is a complex complication with two characteristics of capsular contracture and heterotopic ossification. Currently, genomic mechanisms and pathogenesis of posttraumatic elbow stiffness remain inadequately understood. This study aims to identify differentially expressed genes (DEGs) and elucidate molecular networks of posttraumatic elbow stiffness, providing novel insights into disease mechanisms at transcriptome level.

Methods

Global transcriptome sequencing was conducted on six capsular samples from individuals with posttraumatic elbow stiffness and three control capsular samples from individuals with elbow fractures. Differentially expressed genes (DEGs), microRNAs, and long non-coding RNAs (LncRNAs) were identified and analyzed. Functional enrichment analysis was performed, and the associated protein-protein interaction (PPI) network was constructed. MicroRNAs targeting these DEGs were identified, and transcription factors (TFs) targeting DEGs were predicted using the ENCODE database. Finally, key DEGs were validated by quantitative real-time polymerase chain reaction (qRT-PCR).

Results

A total of 4909 DEGs associated with protein-coding, LncRNA and microRNA were detected, including 2124 upregulated and 2785 downregulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the DEGs were significantly enriched in 36 signaling pathways, notably involving inflammatory responses and extracellular matrix (ECM) receptor interactions. The protein-protein interaction (PPI) network analysis highlighted genes such as SPP1, IBSP, MMP13 and MYO1A as having higher degrees of connectivity. Key microRNAs (hsa-miR-186-5p, hsa-miR-515-5p, and hsa-miR-590-3p) and transcription factors (TFDP1 and STAT3) were predicted to be implicated in the pathogenesis of posttraumatic elbow stiffness through the microRNA-transcription factor regulatory network analysis.

Conclusion

The study provided insights into the molecular mechanisms underlying the changes in the contracted capsules associated with posttraumatic elbow stiffness. Hub genes including SPP1, IBSP, MMP13, and MYO1A, key microRNAs (has-miR-186-5p, has-miR-515-5p, hsa-miR-590-3p) and TFs (TFDP1 and STAT3) may serve as prognostic and therapeutic targets of posttraumatic elbow stiffness, and provide a new idea for the future research direction of clinical treatment.

Extracorporeal Shock Wave and Melatonin Alleviate Joint Capsule Fibrosis after Knee Trauma in Rats by Regulating Autophagy

BACKGROUND

Joint contracture is a common clinical problem affecting joint function. Capsule fibrosis plays a pivotal role in the progression of joint contracture. Previous studies have reported that autophagy plays a regulatory role in visceral fibrosis.

OBJECTIVE

This study aimed to investigate whether extracorporeal shock wave therapy (ESWT) and melatonin alleviate joint capsule fibrosis in rats with extended knee joint contracture by regulating autophagy.

METHODS

A rat traumatic knee joint extension contracture model was made. Then, the rats were treated with ESWT, melatonin, ESWT + melatonin, or ESWT + melatonin + mTOR agonist for 4 weeks. The range of motion (ROM) of the knee joints was measured. Joint capsules were collected and observed for pathological changes by H&E and Masson staining. LC3B protein expression was evaluated by immunofluorescence staining. TGF-β1, MMP-1, Col-Ⅰ, Col-Ⅲ, LC3, ATG7, Beclin1, p-AMPK, p-mTOR and p-ULK1 protein expressions were measured by Western blot assay.

RESULTS

The intervention groups had significantly improved ROM of knee joint (P < 0.05), significantly improved pathological changes on HE and Masson staining, significantly decreased protein expressions of TGF-β1, MMP-1, Col-Ⅰ, Col-Ⅲ and pmTOR (P < 0.05), and significantly increased protein expressions of LC3B, LC3II/LC3I ratio, ATG7, Beclin1, p-AMPK, and p-ULK1 (P < 0.05). Among these groups, the effects demonstrated by the ESWT + melatonin group were the best. With the mTOR agonist supplement, the therapeutic effects of extracorporeal shock waves and melatonin were significantly reduced.

CONCLUSION

ESWT plus melatonin alleviated knee joint capsule fibrosis in rats by regulating autophagy.

Platelet-rich plasma applications in the larynx: snake oil or stupendous?

PURPOSE OF REVIEW

To explore and summarize recent work examining the use of platelet-rich plasma (PRP) applications for vocal fold disorder.

RECENT FINDINGS

Intrachordal PRP injections have recently emerged as a treatment option for patients with damage to the lamina propria of the vocal fold (scar, atrophy, sulcus and inflammatory lesions). Studies support significant improvements in patient-reported and clinician-reported outcomes, and objective phonatory parameters. PRP demonstrates a good safety profile, absence of immune reactions, affordable cost model and improvement in mucosal wave features with resultant improved voice quality up to 12 months following treatment.

SUMMARY

PRP injection of the vocal folds is a novel repurposing of a previously validated technique, and emerging data shows consistent results across multiple centres, increasing confidence in use of this freely available material. Current published studies confirm improved voice outcomes compared with pretreatment measures and high patient satisfaction. Further research is required to properly assign the role of and ideal candidate for PRP applications, and to delineate durability of treatment.

The Well-Forgotten Old: Platelet-Rich Plasma in Modern Anti-Aging Therapy

Currently, approaches to personalized medicine are actively developing. For example, the use of platelet-rich plasma (PRP) is actively growing every year. As a result of activation, platelets release a wide range of growth factors, cytokines, chemokines, and angiogenic factors, after which these molecules regulate chemotaxis, inflammation, and vasomotor function and play a crucial role in restoring the integrity of damaged vascular walls, angiogenesis, and tissue regeneration. Due to these characteristics, PRP has a wide potential in regenerative medicine and gerontology. PRP products are actively used not only in esthetic medicine but also to stimulate tissue regeneration and relieve chronic inflammation. PRP therapy has a number of advantages, but the controversial results of clinical studies, a lack of standardization of the sample preparation of the material, and insufficient objective data on the evaluation of efficacy do not allow us to unambiguously look at the use of PRP for therapeutic purposes. In this review, we will examine the current clinical efficacy of PRP-based products and analyze the contribution of PRP in the therapy of diseases associated with aging.

Platelet Rich plasma injection of the vocal folds in benign vocal pathologies

PURPOSE

There are few options for treatment of dysphonia secondary to vocal pathology related to lamina propria scar, atrophy, sulcus, or inflammatory disorders. Platelet rich plasma (PRP) may provide anti-inflammatory and regenerative properties seen with other tissue engineering therapies without the risks associated with these treatments. We evaluated vocal fold (VF) injection of PRP for feasibility, phonatory effects, patient satisfaction and durability.

METHODS

Patients with dysphonia secondary to vocal fold scar, atrophy, sulcus and inflammatory lesions were included. PRP injections were administered in office, to bilateral vocal folds. Patients were followed up at 1 week, 1 month, 3 months and 6 months to assess outcomes (GRBAS scale, maximum phonation time, vocal fatigue index (VFI), voice handicap index (VHI-10) and stroboscopy).

RESULTS

75 intracordal PRP injections were administered to 48 patients. All injections were completed, and no adverse reactions were experienced. Improvements in VHI-10 scores at 1,3,6 months were seen (mean VHI 21.73 at baseline, 15.62 at six months, p < 0.001). 72.3% rated improvement at 7 or above on Likert scale. 95.7% of patients would consider a future PRP injection. Secondary outcomes VFI, MPT, and GRBAS also demonstrated significant improvements over time. Patients receiving a single PRP injection (n = 26) still demonstrated significant VHI-10 improvements at 1,3 and 6 months.

CONCLUSIONS

VF office PRP injections are feasible and safe and can provide phonatory benefit and reduce vocal effort in benign VF disorders. A single PRP injection is sufficient to provide sustained benefit in some cases.

LEVEL OF EVIDENCE

Level III: prospective cohort study.

Biomechanical outcomes of pharmacological therapies for post-traumatic arthrofibrosis in preclinical animal models: a systematic review and meta-analysis

PURPOSE/AIM OF THE STUDY

There is still no evidence of which drug has the greatest therapeutic potential for post-traumatic arthrofibrosis. The aim of this study is to systematically review the literature for quality evidence and perform a meta-analysis about the pharmacological therapies of post-traumatic arthrofibrosis in preclinical models.

MATERIALS AND METHODS

A comprehensive and systematic search strategy was performed in three databases (MEDLINE, EMBASE and Web of Science) retrieving studies on the effectiveness of pharmacological therapies in the management of post-traumatic arthrofibrosis using preclinical models in terms of biomechanical outcomes. Risk of bias assessment was performed using the SYRCLE's risk of bias tool. A meta-analysis using a random-effects model was conducted if a minimum of three studies reported homogeneous outcomes for drugs with the same action mechanism.

RESULTS

Forty-six studies were included in the systematic review and evaluated for risk of bias. Drugs from 6 different action mechanisms of 21 studies were included in the meta-analysis. Overall, the methodological quality of the studies was poor. Statistically significant overall effect in favor of reducing contracture was present for anti-histamines (Chi2 p = 0.75, I2 = 0%; SMD (Standardized Mean Difference) = -1.30, 95%CI: -1.64 to -0.95, p < 0.00001) and NSAIDs (Chi2 p = 0.01, I2 = 63%; SMD= -0.93, 95%CI: -1.58 to -0.28, p = 0.005).

CONCLUSIONS

Anti-histamines, particularly ketotifen, have the strongest evidence of efficacy for prevention of post-traumatic arthrofibrosis. Some studies suggest a potential role for NSAIDs, particularly celecoxib, although heterogeneity among the included studies is significant.

Porcine platelet lysates exert the efficacy of chondroregeneration and SMAD2-mediated anti-chondrofibrosis on knee osteoarthritis

BACKGROUND

The lack of self-repairability in cartilage and the formation of fibrocartilage pose significant challenges in treating knee osteoarthritis, and there is still no ideal solution. Autologous platelet lysates have been clinically applied to treat kOA and exert satisfactory cartilage-repair efficacy, but the preparation of human PL brings damage to patients and is hardly standardized.

METHODS

In this study, porcine PL was developed to replace hPL, and its chondroregenerative and anti-chondrofibrosis effects were explored. Enzyme-Linked Immunosorbent Assay was applied to qualify the PL products. In vivo, partial-thickness cartilage defects were created on rats as a kOA model, and the von Frey test, histopathological observation, immunohistochemical analysis, and western blot analysis were conducted. In vitro, CCK-8 assay, real-time PCR analysis, immunofluorescence test, and WB analysis were conducted for the mechanism study of pPL.

RESULTS

The in vivo data showed that pPL significantly repaired the cartilage defect by improving matrix synthesis and also ameliorated the pain response in the kOA model of rats. In addition, pPL exerted an anti-fibrosis effect on cartilage by suppressing the expressions of COL1, COL3, α-SMA, VIMENTIN, SMAD2, p-SMAD2, and CTGF in cartilage. The in vitro data verified these effects and indicated that the SMAD2 pathway mediated the anti-fibrosis mechanism of pPL. Moreover, the comparable effects between pPL and rat PL indicate that there is no immune rejection from pPL.

CONCLUSIONS

This study firstly demonstrated the anti-kOA effects of pPL on both cartilage-repair and anti-chondrofibrosis. It developed pPL as a promising alternative to autologous PL for clinical applications.

Time-Series Expression Profile Analysis of Post-Traumatic Joint Contracture in Rats at the Early Stages of the Healing Process

Objective

This study aimed to characterize the gene expression profile at the early stages of the healing process of post-traumatic joint contracture (PTJC).

Methods

Twelve rats were used for PTJC model establishment and were divided into four groups according to the sampling time: S0d, S3d, S7d and S2w. Transcriptome sequencing was performed on fibrotic joint capsule samples in four groups followed by bioinformatics analyses including differentially expressed genes (DEGs) screening, Short Time-series Expression Miner (STEM) analysis, network construction, and pathway analysis. Five important genes were validated by qRT-PCR.

Results

A total of 1171, 1052 and 793 DEGs were screened in S3d vs S0d, S7d vs S0d, and S2w vs S0d comparison groups, respectively. A total of 383 overlapping genes were screened out, which were significantly enriched in some inflammatory functions and pathways. Through STEM analysis, three clusters were identified, including 105, 57 and 57 DEGs, respectively. Then, based on the cluster genes, 10 genes, such as Il6, Timp1, Cxcl1, Cxcr4 and Mmp3, were further selected after PPI and pathway analyses. The expression levels of Il6, Timp1, Cxcl1, Cxcr4 and Mmp3 were validated by qRT-PCR.

Conclusion

The present study screened out several genes with significant changes in expression levels at the early stages of the healing process in PTJC, such as Il6, Timp1, Cxcl1, Cxcr4 and Mmp3. Our study offers a valuable contribution to the understanding pathomechanism of PTJC.