Dual-engineered cartilage-targeting extracellular vesicles derived from mesenchymal stem cells enhance osteoarthritis treatment via miR-223/NLRP3/pyroptosis axis: Toward a precision therapy

Collagen binding and mimetic peptide-functionalized self-assembled peptide hydrogel enhance chondrogenic differentiation of human mesenchymal stem cells

The avascular structure and low cell migration to the damaged area due to the low number of cells do not allow spontaneous repair of the articular cartilage tissue. Therefore, functional scaffolds obtained from biomaterials are used for the regeneration of cartilage tissue. Here, we functionalized one of the self-assembling peptide (SAP) scaffolds KLD (KLDLKLDLKLDL) with short bioactive motifs, which are the α1 chain of type II collagen binding peptide WYRGRL (C1) and the triple helical collagen mimetic peptide GFOGER (C2) by direct coupling. Our goal was to develop injectable functional SAP hydrogels with proper mechanical characteristics that would improve chondrogenesis. Scanning electron microscopy (SEM) was used to observe the integration of peptide scaffold structure at the molecular level. To assure the stability of SAPs, the rheological characteristics and degradation profile of SAP hydrogels were assessed. The biochemical study of the DNA, glycosaminoglycan (GAG), and collagen content revealed that the developed bioactive SAP hydrogels greatly increased hMSCs proliferation compared with KLD scaffolds. Moreover, the addition of bioactive peptides to KLD dramatically increased the expression levels of important chondrogenic markers such as aggrecan, SOX-9, and collagen Type II as evaluated by real-time polymerase chain reaction (PCR). We showed that hMSC proliferation and chondrogenic differentiation were encouraged by the developed SAP scaffolds. Although the chondrogenic potentials of WYRGRL and GFOGER were previously investigated, no study compares the effect of the two peptides integrated into 3-D SAP hydrogels in chondrogenic differentiation. Our findings imply that these specifically created bioactive peptide scaffolds might help enhance cartilage tissue regeneration.

Regulation of ferroptosis in osteoarthritis and osteoarthritic chondrocytes by typical MicroRNAs in chondrocytes

Osteoarthritis (OA) is a progressive degenerative disorder impacting bones and joints, worsened by chronic inflammation, immune dysregulation, mechanical stress, metabolic disturbances, and various other contributing factors. The complex interplay of cartilage damage, loss, and impaired repair mechanisms remains a critical and formidable aspect of OA pathogenesis. At the genetic level, multiple genes have been implicated in the modulation of chondrocyte metabolism, displaying both promotive and inhibitory roles. Recent research has increasingly focused on the influence of non-coding RNAs in the regulation of distinct cell types within bone tissue in OA. In particular, an expanding body of evidence highlights the regulatory roles of microRNAs in OA chondrocytes. This review aims to consolidate the most relevant microRNAs associated with OA chondrocytes, as identified in recent studies, and to elucidate their involvement in chondrocyte metabolic processes and ferroptosis. Furthermore, this study explores the complex regulatory interactions between long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in OA, with an emphasis on microRNA-mediated mechanisms. Finally, critical gaps in the current research are identified, offering strategic insights to advance the understanding of OA pathophysiology and guide therapeutic developments in this field.

IL-18 biology in severe asthma

The role of interleukin-18 (IL-18) and inflammasomes in chronic inflammatory airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), has garnered significant attention in recent years. This review aims to provide an overview of the current understanding of IL-18 biology, the associated signaling pathways, and the involvement of inflammasome complexes in airway diseases. We explore the multifaceted role of IL-18 in asthma pathophysiology, including its interactions with other cytokines and contributions to both T2 and non-T2 inflammation. Importantly, emerging evidence highlights IL-18 as a critical player in severe asthma, contributing to chronic airway inflammation, airway hyperresponsiveness (AHR), and mucus impaction. Furthermore, we discuss the emerging evidence of IL-18's involvement in autoimmunity and highlight potential therapeutic targets within the IL-18 and inflammasome pathways in severe asthma patients with evidence of infections and airway autoimmune responses. By synthesizing recent advancements and ongoing research, this review underscores the importance of IL-18 as a potential novel therapeutic target in the treatment of severe asthma and other related conditions.

Research hotspots and trends of mesenchymal stem cell-derived extracellular vesicles for drug delivery: a bibliometric and visualization analysis from 2013 to 2023

Introduction

Our study aims to provide a comprehensive overview of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) in drug delivery research, focusing on the period between 2013 and 2023. Given the increasing global interest in this field, we utilized bibliometric tools to explore publication trends, key contributors, and thematic research clusters.

Methods

Data was collected from the Web of Science (WoS) database, and an in-depth bibliometric analysis was conducted using VOSviewer. The analysis encompassed bibliographic coupling, co-citation, co-authorship, and co-occurrence trends, offering a structured insight into global research activity. We also employed Citespace to further analyze thematic clusters in this domain.

Results

Our analysis revealed a total of 1,045 publications related to MSC-EVs in drug delivery over the past decade, showing a steady increase in research output. China led in publication count, H-index, prolific authors, and research funding, while the United States ranked highest in total citations, average citation counts, and H-index performance. Pharmaceutics emerged as the leading journal by publication volume, with the Journal of Controlled Release having the strongest total link strength. Top institutions driving research included Shanghai Jiao Tong University, Zhejiang University, and Harvard University. VOSviewer analysis identified four major research clusters: tissue engineering, cancer, neurological diseases, and targeted delivery. Citespace analysis refined this further into ten thematic areas, including differentiation, tissue regeneration, and drug resistance.

Discussion

This bibliometric assessment provides a holistic visualization of the research landscape for MSC-EVs in drug delivery, underlining the significant contributions of China and the United States. Our findings underscore the increasing global importance of MSC-EV research and highlight emerging themes that will likely guide future research directions. The insights from this study offer a foundational framework for identifying nascent frontiers in MSC-EV-based drug delivery.

The Therapeutic Potential of Exosomes vs. Matrix-Bound Nanovesicles from Human Umbilical Cord Mesenchymal Stromal Cells in Osteoarthritis Treatment

Osteoarthritis (OA) is a degenerative joint disease with limited therapeutic options, where inflammation plays a critical role in disease progression. Extracellular vesicles (EV) derived from mesenchymal stromal cells (MSC) have shown potential as a therapeutic approach for OA by modulating inflammation and alleviating degenerative processes in the joint. This study evaluated the therapeutic effects for the treatment of OA of two types of EV-exosomes and matrix-bound nanovesicles (MBV)-both derived from the human umbilical cord MSC (UC-MSC) via differential ultracentrifugation. Different phenotypes of human monocyte-derived macrophages (MDM) were used to study the anti-inflammatory properties of EV in vitro, and the medial meniscectomy-induced rat model of knee osteoarthritis (MMx) was used in vivo. The study found that both EV reduced pro-inflammatory cytokines IL-6 and TNF-α in MDM. However, exosomes showed superior results, preserving the extracellular matrix (ECM) of hyaline cartilage, and reducing synovitis more effectively than MBVs. Additionally, exosomes downregulated inflammatory markers (TNF-α, iNOS) and increased Arg-1 expression in macrophages and synovial fibroblasts, indicating a stronger anti-inflammatory effect. These results suggest UC-MSC exosomes as a promising therapeutic option for OA, with the potential for modulating inflammation and promoting joint tissue regeneration.

IRF1-mediated upregulation of PARP12 promotes cartilage degradation by inhibiting PINK1/Parkin dependent mitophagy through ISG15 attenuating ubiquitylation and SUMOylation of MFN1/2

Osteoarthritis (OA) is an age-related cartilage-degenerating joint disease. Mitochondrial dysfunction has been reported to promote the development of OA. Poly (ADP-ribose) polymerase family member 12 (PARP12) is a key regulator of mitochondrial function, protein translation, and inflammation. However, the role of PARP12 in OA-based cartilage degradation and the underlying mechanisms are relatively unknown. Here, we first demonstrated that PARP12 inhibits mitophagy and promotes OA progression in human OA cartilage and a monosodium iodoacetate-induced rat OA model. Using mass spectrometry and co-immunoprecipitation assay, PARP12 was shown to interact with ISG15, upregulate mitofusin 1 and 2 (MFN1/2) ISGylation, which downregulated MFN1/2 ubiquitination and SUMOylation, thereby inhibiting PINK1/Parkin-dependent chondrocyte mitophagy and promoting cartilage degradation. Moreover, inflammatory cytokine-induced interferon regulatory factor 1 (IRF1) activation was required for the upregulation of PARP12 expression, and it directly bound to the PARP12 promoter to activate transcription. XAV-939 inhibited PARP12 expression and suppressed OA pathogenesis in vitro and in vivo. Clinically, PARP12 can be used to predict the severity of OA; thus, it represents a new target for the study of mitophagy and OA progression. In brief, the IRF1-mediated upregulation of PARP12 promoted cartilage degradation by inhibiting PINK1/Parkin-dependent mitophagy via ISG15-based attenuation of MFN1/2 ubiquitylation and SUMOylation. Our data provide new insights into the molecular mechanisms underlying PARP12-based regulation of mitophagy and can facilitate the development of therapeutic strategies for the treatment of OA.

Mechanisms of chondrocyte cell death in osteoarthritis: implications for disease progression and treatment

Osteoarthritis (OA) is a chronic joint disease characterized by the degeneration, destruction, and excessive ossification of articular cartilage. The prevalence of OA is rising annually, concomitant with the aging global population and increasing rates of obesity. This condition imposes a substantial and escalating burden on individual health, healthcare systems, and broader social and economic frameworks. The etiology of OA is multifaceted and not fully understood. Current research suggests that the death of chondrocytes, encompassing mechanisms such as cellular apoptosis, pyroptosis, autophagy, ferroptosis and cuproptosis, contributes to both the initiation and progression of the disease. These cell death pathways not only diminish the population of chondrocytes but also exacerbate joint damage through the induction of inflammation and other deleterious processes. This paper delineates the morphological characteristics associated with various modes of cell death and summarizes current research results on the molecular mechanisms of different cell death patterns in OA. The objective is to review the advancements in understanding chondrocyte cell death in OA, thereby offering novel insights for potential clinical interventions.

Mesenchymal stem cells and their extracellular vesicles in bone and joint diseases: targeting the NLRP3 inflammasome

The nucleotide-binding oligomerization domain-like-receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a cytosolic multi-subunit protein complex, and recent studies have demonstrated the vital role of the NLRP3 inflammasome in the pathological and physiological conditions, which cleaves gasdermin D to induce inflammatory cell death called pyroptosis and mediates the release of interleukin-1 beta and interleukin-18 in response to microbial infection or cellular injury. Over-activation of the NLRP3 inflammasome is associated with the pathogenesis of many disorders affecting bone and joints, including gouty arthritis, osteoarthritis, rheumatoid arthritis, osteoporosis, and periodontitis. Moreover, mesenchymal stem cells (MSCs) have been discovered to facilitate the inhibition of NLRP3 and maybe ideal for treating bone and joint diseases. In this review, we implicate the structure and activation of the NLRP3 inflammasome along with the detail on the involvement of NLRP3 inflammasome in bone and joint diseases pathology. In addition, we focused on MSCs and MSC-extracellular vesicles targeting NLRP3 inflammasomes in bone and joint diseases. Finally, the existing problems and future direction are also discussed.

Picroside II suppresses chondrocyte pyroptosis through MAPK/NF-κB/NLRP3 signaling pathway alleviates osteoarthritis

BACKGROUND

Picroside II (P-II) is the main bioactive constituent of Picrorhiza Kurroa, a traditional Chinese herb of interest for its proven anti-inflammatory properties. Its beneficial effects have been noted across several physiological systems, including the nervous, circulatory, and digestive, capable of treating a wide range of diseases. Nevertheless, the potential of Picroside II to treat osteoarthritis (OA) and the mechanisms behind its efficacy remain largely unexplored.

AIM

This study aims to evaluate the efficacy of Picroside II in the treatment of osteoarthritis and its potential molecular mechanisms.

METHODS

In vitro, we induced cellular inflammation in chondrocytes with lipopolysaccharide (LPS) and subsequently treated with Picroside II to assess protective effect on chondrocyte. We employed the Cell Counting Kit-8 (CCK-8) assay to assess the impact of Picroside II on cell viability and select the optimal Picroside II concentration for subsequent experiments. We explored the effect of Picroside II on chondrocyte pyroptosis and its underlying molecular mechanisms by qRT-PCR, Western blot (WB) and immunofluorescence. In vivo, we established the destabilization of the medial meniscus surgery to create an OA mouse model. The therapeutic effects of Picroside II were then assessed through Micro-CT scanning, Hematoxylin-eosin (H&E) staining, Safranin O-Fast Green (S&F) staining, immunohistochemistry and immunofluorescence.

RESULTS

In in vitro studies, toluidine blue and CCK-8 results showed that a certain concentration of Picroside II had a restorative effect on the viability of chondrocytes inhibited by LPS. Picroside II notably suppressed the expression levels of caspase-1, IL-18, and IL-1β, which consequently led to the reduction of pyroptosis. Moreover, Picroside II was shown to decrease NLRP3 inflammasome activation, via the MAPK/NF-κB signaling pathway. In vivo studies have shown that Picroside II can effectively reduce subchondral bone destruction and osteophyte formation in the knee joint of mice after DMM surgery.

CONCLUSIONS

Our research suggests that Picroside II can inhibit chondrocyte pyroptosis and ameliorate osteoarthritis progression by modulating the MAPK/NF-κB signaling pathway.

Contents of exosomes derived from adipose tissue and their regulation on inflammation, tumors, and diabetes

Adipose tissue (AT) serves as an energy-capacitive organ and performs functions involving paracrine- and endocrine-mediated regulation via extracellular vesicles (EVs) secretion. Exosomes, a subtype of EVs, contain various bioactive molecules with regulatory effects, such as nucleic acids, proteins, and lipids. AT-derived exosomes (AT-exos) include exosomes derived from various cells in AT, including adipocytes, adipose-derived stem cells (ADSCs), macrophages, and endothelial cells. This review aimed to comprehensively evaluate the impacts of different AT-exos on the regulation of physiological and pathological processes. The contents and functions of adipocyte-derived exosomes and ADSC-derived exosomes are compared simultaneously, highlighting their similarities and differences. The contents of AT-exos have been shown to exert complex regulatory effects on local inflammation, tumor dynamics, and insulin resistance. Significantly, differences in the cargoes of AT-exos have been observed among diabetes patients, obese individuals, and healthy individuals. These differences could be used to predict the development of diabetes mellitus and as therapeutic targets for improving insulin sensitivity and glucose tolerance. However, further research is needed to elucidate the underlying mechanisms and potential applications of AT-exos.

Exercise-Induced Central Fatigue: Biomarkers, and Non-Medicinal Interventions

Fatigue, commonly experienced in daily life, is a feeling of extreme tiredness, shortage or lack of energy, exhaustion, and difficulty in performing voluntary tasks. Central fatigue, defined as a progressive failure to voluntarily activate the muscle, is typically linked to moderate- or light-intensity exercise. However, in some instances, high-intensity exercise can also trigger the onset of central fatigue. Exercise-induced central fatigue often precedes the decline in physical performance in well-trained athletes. This leads to a reduction in nerve impulses, decreased neuronal excitability, and an imbalance in brain homeostasis, all of which can adversely impact an athlete's performance and the longevity of their sports career. Therefore, implementing strategies to delay the onset of exercise-induced central fatigue is vital for enhancing athletic performance and safeguarding athletes from the debilitating effects of fatigue. In this review, we discuss the structural basis, measurement methods, and biomarkers of exercise-induced central fatigue. Furthermore, we propose non-pharmacological interventions to mitigate its effects, which can potentially foster improvements in athletes' performances in a healthful and sustainable manner.

Harnessing Nanomedicine for Cartilage Repair: Design Considerations and Recent Advances in Biomaterials

Cartilage injuries are escalating worldwide, particularly in aging society. Given its limited self-healing ability, the repair and regeneration of damaged articular cartilage remain formidable challenges. To address this issue, nanomaterials are leveraged to achieve desirable repair outcomes by enhancing mechanical properties, optimizing drug loading and bioavailability, enabling site-specific and targeted delivery, and orchestrating cell activities at the nanoscale. This review presents a comprehensive survey of recent research in nanomedicine for cartilage repair, with a primary focus on biomaterial design considerations and recent advances. The review commences with an introductory overview of the intricate cartilage microenvironment and further delves into key biomaterial design parameters crucial for treating cartilage damage, including microstructure, surface charge, and active targeting. The focal point of this review lies in recent advances in nano drug delivery systems and nanotechnology-enabled 3D matrices for cartilage repair. We discuss the compositions and properties of these nanomaterials and elucidate how these materials impact the regeneration of damaged cartilage. This review underscores the pivotal role of nanotechnology in improving the efficacy of biomaterials utilized for the treatment of cartilage damage.

Identification of novel potential drugs for the treatment and prevention of osteoarthritis

Objectives

Osteoarthritis (OA) is characterized by a high prevalence, poor prognosis, and a propensity to lead to disability. Despite the availability of standard therapies, they are associated with potential side effects and don't provide a complete cure for patients. Consequently, there is an urgent demand for the development of novel drugs.

Method

The gene expression profiles (GSE64394, GSE178557 and GSE215039) of normal and OA chondrocytes samples were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified by the "LIMMA" R package. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were conducted using the R package clusterProfiler. A protein-protein (PPI) interaction network was performed to identify hub genes by using the Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape. Small molecule compounds linked to OA were predicted through the NetworkAnalyst platform. Finally, molecular docking was conducted using AutoDock and Pymol software.

Results

We identified 98 DEGs primarily implicated in endochondral ossification, extracellular matrix degradation, and Wnt signaling pathways. 23 DEGs were closely associated with OA, and 10 hub genes were found to be potential drug targets for OA. Two new targeted compounds, tetrachlorodibenzodioxin (TCDD) and valproic acid (VPA), were screened. And they both exhibited strong binding affinity to their respective targets.

Conclusions

Reducing exposure to TCDD could be a crucial strategy in preventing OA, and VPA has gained recognition as a novel drug candidate for OA treatment.

The Role of Extracellular Vesicles in the Pathogenesis and Treatment of Rheumatoid Arthritis and Osteoarthritis

Cells can communicate with each other through extracellular vesicles (EVs), which are membrane-bound structures that transport proteins, lipids and nucleic acids. These structures have been found to mediate cellular differentiation and proliferation apoptosis, as well as inflammatory responses and senescence, among others. The cargo of these vesicles may include immunomodulatory molecules, which can then contribute to the pathogenesis of various diseases. By contrast, EVs secreted by mesenchymal stem cells (MSCs) have shown important immunosuppressive and regenerative properties. Moreover, EVs can be modified and used as drug carriers to precisely deliver therapeutic agents. In this review, we aim to summarize the current evidence on the roles of EVs in the progression and treatment of rheumatoid arthritis (RA) and osteoarthritis (OA), which are important and prevalent joint diseases with a significant global burden.

Novel 3D-printing bilayer GelMA-based hydrogel containing BP,β-TCP and exosomes for cartilage-bone integrated repair

The integrated repair of cartilage and bone involves the migration and differentiation of cells, which has always been a difficult problem to be solved. We utilize the natural biomaterial gelatin to construct gelatin methacryloyl (GelMA), a hydrogel scaffold with high cell affinity. GelMA is mixed with different components to print a bi-layer porous hydrogel scaffold with different modulus and composition in upper and lower layers through three-dimensional (3D) printing technology. The upper scaffold adds black phosphorus (BP) and human umbilical cord mesenchymal stem cells (hUMSCs) exosomes (exos) in GelMA, which has a relatively lower elastic modulus and is conducive to the differentiation of BMSCs into cartilage. In the lower scaffold, in addition to BP and hUMSCs exos,β-tricalcium phosphate (β-TCP), which has osteoconductive and osteoinductive effects, is added to GelMA. The addition ofβ-TCP significantly enhances the elastic modulus of the hydrogel scaffold, which is conducive to the osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs).In vitroexperiments have confirmed that the bi-layer scaffolds can promote osteogenesis and chondrogenic differentiation respectively. And in the rabbit cartilage-bone injury model, MRI and micro-CT results show that the 3D printed bi-layer GelMA composite scaffold has a repair effect close to normal tissue.