IL-6 Reduces Spheroid Sizes of Osteophytic Cells Derived from Osteoarthritis Knee Joint via Induction of Apoptosis

Relationship between high-sensitivity C-reactive protein to lymphocyte ratio (hs-CLR) and incision complications following medial opening-wedge high tibial osteotomy for knee osteoarthritis

PURPOSE

Inflammatory and markers have a vital role in the development and prediction of adverse events following surgical procedures. This study aims to examine the relationship between high-sensitivity C-reactive protein to lymphocyte ratio (hs-CLR) and incision complications (ie, poor healing of superficial incisions, wound infection) following medial opening-wedge high tibial osteotomy (MOWHTO) for unicompartmental knee osteoarthritis (KOA).

METHODS

This retrospective study analyzed patients who underwent MOWHTO for varus KOA between January 2021 and June 2024 in two tertiary referral hospitals. Baseline characteristics and laboratory test results were obtained through a review of inpatient medical records. The primary outcome measure was the incidence of incision complications occurring within 30 days postoperatively, determined by examining both inpatient records and outpatient follow-up documentation after discharge. To explore the relationship between hs-CLR and incision complications, we employed restricted cubic spline (RCS) analysis, receiver operating characteristic (ROC) curves, as well as univariate and multivariate logistic regression models.

RESULTS

There were 528 participants, including 190 males and 338 females, with a mean age of 56.2 ± 6.5 years. Within the 30 days following surgery, 48 patients (9.1%; 95% CI, 6.6% to 11.5%) experienced incision complications. Both the unadjusted and adjusted RCS analyses revealed the consistently significant nonlinear relationship (P < 0.05). ROC curve analysis identified an optimal hs-CLR cut-off value of 1.83, accordingly categorizing patients into low hs-CLR (n = 298) and high hs-CLR (n = 230) groups. Multivariate analyses employing two adjustment techniques demonstrated a significant relationship between a hs-CLR ≥ 1.83 and an increased risk of incision complications, with an odds ratio of 8.08 (95% CI, 3.16 to 20.63; P < 0.001) for "fully adjusted model" and of 8.99 (95%CI, 3.92 to 20.63; P < 0.001) for "backward elimination model".

CONCLUSION

This study demonstrated a robust association between preoperative hs-CLR and the risk of postoperative incision complications following MOWHTO for varus KOA. Although the observed odds ratios were substantial, the wide confidence intervals highlight the need for validation through larger, multicenter studies.

Dynamic profiling of BMSC-dECM reveals accumulation of core matrisome proteins suppresses osteogenic differentiation and bone regeneration

INTRODUCTION

The extracellular matrix (ECM) of bone mesenchymal stem cells (BMSCs) plays a critical role in tissue development and regeneration. Rather than being inert, the ECM exhibits a dynamic structure that determines cell fate.

OBJECTIVES

The aim of this study is to investigate the dynamic composition, functional properties, and underlying mechanisms of BMSC-ECM during osteogenic differentiation. We propose that dynamic alterations in BMSC-ECM, particularly in critical matrix proteins, are essential to regulate osteogenic differentiation and bone regeneration.

METHODS

Dynamic ECM from BMSCs was collected at different time points during culture with or without osteogenic induction, followed by decellularization. A mouse tibial defect model was introduced to assess bone regeneration in vivo. Proteomics was used to analyze the dynamic protein composition pattern, while a comparative transcriptomic analysis further determined the impact of dynamic BMSC-dECM on cellular mRNA profile.

RESULTS

Decellularized ECMs (dECMs) from late noninduced BMSCs exhibited distinct functional properties compared to the other groups. While early noninduced, early osteogenic (Os)-induced and late Os-induced dECMs promoted bone regeneration, late noninduced dECM dramatically inhibited this process. The protein composition of dECMs, rather than the structure or total ECM content, was the key factor determining their dynamic function. Accumulation of core matrisome during noninduced culture resulted in the inhibition of its function. Consistently, the gene expression profiles of replanted BMSCs on early noninduced/Os-induced dECM and late Os-induced dECM were similar, leaving the late noninduced dECM separate. Moreover, the core matrisome of the external dECM negatively regulated intracellular gene expression. Versican (VCAN) and Asporin (ASPN) might be the key ECM proteins influencing bone regeneration.

CONCLUSIONS

Accumulation of the core matrisome during noninduction led to solidification and the inactivation of bone regeneration. Targeting the core matrisome might effectively avoid the drawbacks of noninduced dECM, providing novel strategies for developing highly bioactive stem cell-derived dECM.

Involvement of Heat Shock Protein 47 in Osteophyte Formation of Knee Joint Osteoarthritis

Osteophytes contribute to the development and progression of knee osteoarthritis (OA). Although transforming growth factor-β (TGF-β) and bone morphogenic protein-2 (BMP2) are known to induce osteophytes, regulators of osteophyte formation remain elusive. This study aimed to search for molecules that modulate osteophytosis in a mouse knee OA model. Proteomic analysis, followed by immunohistochemistry of osteophyte and articular cartilage, identified heat shock protein 47 (HSP47), a molecular chaperone for procollagens, as a molecule selectively overexpressed by osteophyte fibrocartilaginous cells. The treatment of TGF-β3 and BMP2 to a three-dimensional pellet culture of mouse mesenchymal stem cells caused their differentiation into osteophyte-like cells accompanied with the up-regulation of HSP47. The pellet sizes of stimulated three-dimensional-cultured mesenchymal stem cells were significantly reduced by knockdown of HSP47 or treatment with AK778 (HSP47 inhibitor), because of increased apoptosis. Furthermore, intra-articular AK778 injections suppressed osteophyte formation in a mouse OA model. Importantly, the studies with human samples demonstrated HSP47 overexpression by osteophyte fibrocartilaginous cells in human OA knee joints. Similarly, the overexpression of HSP47 was observed in the TGF-β3- and BMP2-treated human osteophytic cell spheroids as well as the size reduction of spheroids by AK778 treatment. These findings highlight the promoting function of HSP47 in osteophyte formation in OA knee joints and suggest that therapeutic interventions targeting HSP47 may be of clinical value.

Association between serum high-sensitivity C-reactive protein levels and osteoarthritis in adults from NHANES 2015 to 2018

To explore the association between serum high-sensitivity C-reactive protein (HSCRP) levels and osteoarthritis (OA) in adults, providing new evidence for the diagnosis of adult OA. We selected data from the 2015-2018 National Health and Nutrition Examination Survey (NHANES) and conducted a cross-sectional study. Serum HSCRP levels were extracted from laboratory data, and OA patients were identified through questionnaire responses. Participants under the age of 20 and those with incomplete data were excluded. We used multivariable logistic regression models, restricted cubic spline (RCS) functions, and stratified analyses to study the association between serum HSCRP levels and osteoarthritis in adults. After screening, a total of 9,948 participants were included, among whom 1,196 were osteoarthritis patients, representing a prevalence rate of 12.02%. Multivariable logistic regression analysis, along with three adjusted models, showed a positive correlation between serum HSCRP levels and the occurrence of osteoarthritis in adults. Compared to the lowest HSCRP quartile, the highest quartile showed a 1.86-fold higher prevalence of OA (95% confidence interval: 1.55 ~ 2.23, P < 0.001). The restricted cubic spline analysis showed a significant increase in OA incidence with rising serum HSCRP levels (P < 0.05). Subgroup and forest plot analyses indicated a positive correlation between HSCRP levels and osteoarthritis across different subgroups, such as age, gender, hypertension status, activity status, drinking status, and Smoke status (P < 0.05). There is a positive correlation between serum HSCRP levels and the occurrence of osteoarthritis in adults. When a patient's serum HSCRP level is elevated, the possibility of osteoarthritis should be considered.

Veratridine, a plant-derived alkaloid, suppresses the hyperactive Rictor-mTORC2 pathway: a new targeted therapy for primary and metastatic colorectal cancer

Despite considerable advances to improve colorectal cancer (CRC) survival over the last decade, therapeutic challenges remain due to the rapid metastatic dissemination of primary tumors and screening limitations. Meanwhile, the rise of CRC in younger adults (Early-onset CRC), commonly diagnosed with a metastatic form of the disease, shows the pressing need to develop more effective targeted therapies to decrease the high mortality rates associated with metastatic disease. Hyperactivation of the Rictor-mTORC2-AKT signaling pathway drives key metastatic players in diverse malignant tumors, including early- and late-onset colorectal cancer. Selective mTORC2 inhibitors are becoming a potential treatment strategy for CRC due to the therapeutic limitations of mTORC1 inhibitors. Veratridine (VTD), a lipid-soluble alkaloid extracted from Liliaceae plants, can transcriptionally increase UBXN2A, which induces 26S proteasomal degradation of the Rictor protein, a key member in the mTORC2 complex. Destabilization of Rictor protein by VTD decreases Akt phosphorylation on Ser473, which is responsible for metastatic signaling downstream of the mTORC2 pathway in diverse malignant tumors. VTD decreases the population of metastatic colon cancer stem cells and functions as an angiogenesis inhibitor. VTD effectively reduces the spheroid growth rate and restricts cell migration. Live cell migration and invasion assays alongside biomechanical-force-based experiments revealed that VTD suppresses colon cancer cell invasiveness and the ensuing risk of tumor metastasis. A CRC mouse model that mimics the natural stages of human sporadic CRC revealed that VTD treatment significantly decreases tumor growth in a UBXN2A-dependent manner. This study showed a novel mechanistic connection between a ubiquitin-like protein and mTORC2-dependent migration and invasion in CRC tumors. This study revealed the therapeutic benefit of selective inhibition of Rictor in CRC, particularly in tumors with a hyperactive Rictor-mTORC2 signaling pathway. Finally, this study opened a new platform for repurposing VTD, a supplemental anti-hypertension molecule, into an effective targeted therapy in CRC tumors.

The common link between sleep apnea syndrome and osteoarthritis: a literature review

Patients with Osteoarthritis (OA) often also suffer from Sleep Apnea Syndrome (SAS), and many scholars have started to notice this link, although the relationship between the two is still unclear. In this review, we aim to summarize the current literature on these two diseases, integrate evidence of the OA and OSA connection, explore and discuss their potential common mechanisms, and thus identify effective treatment methods for patients with both OA and SAS. Some shared characteristics of the two conditions have been identified, notably aging and obesity as mutual risk factors. Both diseases are associated with various biological processes or molecular pathways, including mitochondrial dysfunction, reactive oxygen species production, the NF-kB pathway, HIF, IL-6, and IL-8. SAS serves as a risk factor for OA, and conversely, OA may influence the progression of SAS. The effects of OA on SAS are underreported in the literature and require more investigation. To effectively manage these patients, timely intervention for SAS is necessary while treating OA, with weight reduction being a primary requirement, alongside combined treatments such as Continuous positive airway pressure (CPAP) and medications. Additionally, numerous studies in drug development are now aimed at inhibiting or clearing certain molecular pathways, including ROS, NF-KB, IL-6, and IL-8. Improving mitochondrial function might represent a viable new strategy, with further research into mitochondrial updates or transplants being essential.

Medial meniscus extrusion is invariably observed and consistent with tibial osteophyte width in elderly populations: The Bunkyo Health Study

We reported that the full-length width of medial tibial osteophytes comprising cartilage and bone parts correlates with medial meniscus extrusion (MME) in early-stage knee osteoarthritis (OA). However, no data exist on the prevalence of MME and its relationship with osteophytes in the elderly population. 1191 elderly individuals (females 57%; 72.9 years old on average) in the Bunkyo Health Study underwent standing plain radiograph and proton density-weighted MRI on knee joints. MRI-detected OA changes were evaluated according to the Whole-Organ Magnetic Resonance Imaging Score. A new method of assessing the cartilage and bone parts of osteophytes was developed using pseudo-coloring images of proton density-weighted fat-suppressed MRI. Most subjects showed Kellgren-Lawrence grade 1 or 2 radiographic medial knee OA (88.1%), MME (98.7%, 3.90 ± 2.01 mm), and medial tibial osteophytes (99.3%, 3.27 ± 1.50 mm). Regarding OA changes, MME was closely associated with the full-length width of medial tibial osteophytes (β = 1.114; 95% CI 1.069-1.159; p < 0.001) in line with osteophyte width (intraclass correlation coefficient, 0.804; 95% CI 0.783-0.823). Our data revealed that MME and medial tibial osteophytes are observed in the elderly and demonstrate that the degree of MME is consistent with the full-length width of medial tibial osteophytes, suggesting that osteophytes might be implicated in MME.