Internalization of Neutrophil-Derived Microvesicles Modulates TNFα-Stimulated Proinflammatory Cytokine Production in Human Fibroblast-Like Synoviocytes

TLR-4Ab and IFNγAb with exogenous IL-10 treated LPS induced mice shown differential inflammatory response upon RANKL-M-CSF stimulation in resident bone marrow cells

The inflammatory response in bone tissue often triggered by LPS is a complex process. Since LPS through TLR4 and in presence of IFNγ activates osteoclast differentiation and bone resorption, therefore, suppression of osteoclastogenesis through inhibition of TLR4 vs IFNγ mediated inflammation could be a reasonable strategy for the treatment of inflammatory bone loss. Administration of anti-TLR4 (30 mg/kg) and anti-IFNγ antibodies (6.6 mg/kg) were utilized before LPS (5 mg/kg) challenge and subsequently mice were treated with mouse IL-10 (0.02 mg/kg). Then RBMCs were isolated from different groups of mice and stimulated (in vitro) with M-CSF (10 ng/ml) and RANKL (10 ng/ml) to induce bone marrow cell differentiation in presence of LPS (100 ng/ml). The involvement of RANKL and M-CSF in the regulation of bone inflammation underlines the intricate signaling pathways. Furthermore, the study sheds light on the potential therapeutic effects of exogenous IL-10 possibly through STAT3 signaling in the RBMCs. The use of antibodies against TLR4 and IFNγ, in conjugation with IL-10in LPS bone damage model, appears to downregulate the activation of NF-κB, and reduction of many pro-inflammatory cytokines regulating the inflammatory cascade in RBMC. This suggests a promising avenue for the development of treatments aimed at mitigating bone inflammation associated with bacterial infections. Therefore, inhibition of TLR4 and IFNγ could be explored as potential therapeutic agents against LPS induced bone loss.

IL-1β mediated fibroblast-neutrophil crosstalk promotes inflammatory environment in skin lesions of SLE

Systemic lupus erythematosus (SLE) is characterized by immune dysregulation, with neutrophil infiltration in skin lesions contributing to inflammation and disease progression. However, the interaction between fibroblasts and neutrophils in SLE skin lesions has not been fully explored. Using single-cell RNA sequencing, we identified a unique CXCL1+ fibroblast subset in SLE lesions. We found that CXCL1+ fibroblasts recruit and activate neutrophils, increasing the production of inflammatory mediators, reactive oxygen species, and neutrophil extracellular traps. These fibroblasts also facilitated the transition of neutrophils to a low-density phenotype. Notably, these fibroblasts delayed neutrophil apoptosis, extending their survival and amplifying inflammation. Serum amyloid A1, secreted by CXCL1+ fibroblasts, emerged as a key activator of neutrophils. Activated neutrophils, in turn, secreted IL-1β to induce CXCL1+ fibroblasts differentiation via activating the NF-κB pathway. In conclusion, our findings reveal that IL-1β-induced CXCL1+ fibroblasts significantly modulate pro-inflammatory neutrophils, underscoring the critical crosstalk between fibroblasts and neutrophils in SLE pathogenesis.

Mechanism of drug-pairs Astragalus Mongholicus-Largehead Atractylodes on treating knee osteoarthritis investigated by GEO gene chip with network pharmacology and molecular docking

Investigations into the therapeutic potential of Astragalus Mongholicus (AM, huáng qí) and Largehead Atractylodes (LA, bái zhú) reveal significant efficacy in mitigating the onset and progression of knee osteoarthritis (KOA), albeit with an elusive mechanistic understanding. This study delineates the primary bioactive constituents and their molecular targets within the AM-LA synergy by harnessing the comprehensive Traditional Chinese Medicine (TCM) network databases, including TCMSP, TCMID, and ETCM. Furthermore, an analysis of 3 gene expression datasets, sourced from the gene expression omnibus database, facilitated the identification of differential genes associated with KOA. Integrating these findings with data from 5 predominant databases yielded a refined list of KOA-associated targets, which were subsequently aligned with the gene signatures corresponding to AM and LA treatment. Through this alignment, specific molecular targets pertinent to the AM-LA therapeutic axis were elucidated. The construction of a protein-protein interaction network, leveraging the shared genetic markers between KOA pathology and AM-LA intervention, enabled the identification of pivotal molecular targets via the topological analysis facilitated by CytoNCA plugins. Subsequent GO and KEGG enrichment analyses fostered the development of a holistic herbal-ingredient-target network and a core target-signal pathway network. Molecular docking techniques were employed to validate the interaction between 5 central molecular targets and their corresponding active compounds within the AM-LA complex. Our findings suggest that the AM-LA combination modulates key biological processes, including cellular activity, reactive oxygen species modification, metabolic regulation, and the activation of systemic immunity. By either augmenting or attenuating crucial signaling pathways, such as MAPK, calcium, and PI3K/AKT pathways, the AM-LA dyad orchestrates a comprehensive regulatory effect on immune-inflammatory responses, cellular proliferation, differentiation, apoptosis, and antioxidant defenses, offering a novel therapeutic avenue for KOA management. This study, underpinned by gene expression omnibus gene chip analyses and network pharmacology, advances our understanding of the molecular underpinnings governing the inhibitory effects of AM and LA on KOA progression, laying the groundwork for future explorations into the active components and mechanistic pathways of TCM in KOA treatment.

Immunoengineering Biomaterials for Musculoskeletal Tissue Repair across Lifespan

Musculoskeletal diseases and injuries are among the leading causes of pain and morbidity worldwide. Broad efforts have focused on developing pro-regenerative biomaterials to treat musculoskeletal conditions; however, these approaches have yet to make a significant clinical impact. Recent studies have demonstrated that the immune system is central in orchestrating tissue repair and that targeting pro-regenerative immune responses can improve biomaterial therapeutic outcomes. However, aging is a critical factor negatively affecting musculoskeletal tissue repair and immune function. Hence, understanding how age affects the response to biomaterials is essential for improving musculoskeletal biomaterial therapies. This review focuses on the intersection of the immune system and aging in response to biomaterials for musculoskeletal tissue repair. The article introduces the general impacts of aging on tissue physiology, the immune system, and the response to biomaterials. Then, it explains how the adaptive immune system guides the response to injury and biomaterial implants in cartilage, muscle, and bone and discusses how aging impacts these processes in each tissue type. The review concludes by highlighting future directions for the development and translation of personalized immunomodulatory biomaterials for musculoskeletal tissue repair.

Impact of dual neutralization of TNF-α and IL-1β along with Gentamicin treatment on the functions of blood and splenic neutrophils and its role on improvement of S. aureus induced septic arthritis

Researches of recent past years have emphasized potential of antibiotics to improve septic arthritis but as multi-drug resistant strains like MRSA are emerging fast, new alternative therapeutic advances are high in demand. This study aims to figure out the role of neutrophils in regulating inflammatory responses of S. aureus induced septic arthritis while using TNF-α Ab or IL-1β Ab along with antibiotic gentamicin or both in combination. In this study, role of anti-oxidant enzymes were investigated and correlated with generated ROS level. While expression of TLR2, TNFR2, MMP2, RANKL, SAPK/JNK in the spleen were evaluated through western blot. Serum activity of IL-8, IL-10, IL-12, OPG, OPN, CRP was assessed using ELISA. Flow cytometry study evaluated inflamed neutrophil population. Results have shown TNF-α neutralization along with gentamicin was able to reduce arthritic swelling prominently. While combination therapy effectively reduced blood neutrophil ROS activity, arginase activity, MPO activity along with spleen bacterial burden. Serum OPG, CRP, IL-10 level got reduced while serum OPN, IL-8 and IL-12 level enhanced in treatment groups, showing mitigation of inflammatory damage. Overall, it is a novel work that observed how antibiotic and antibody therapy enhanced neutrophil function positively to combat sepsis. This study may not be fully applicable in clinical trials as it is performed with animal model. Clinical trials include crystalline and inflammatory arthritides, trauma, neoplasm. Interdisciplinary collaboration between radiology, orthopaedic surgery and knowledge of animal system responses may give better idea to find proper therapeutic approach in future research works.

Research progress of exosomes as drug carriers in cancer and inflammation

Extracellular vesicles (EVs) could be produced by most cells and play an important role in disease development. As a subtype of EVs, exosomes exhibit suitable size, rich surface markers and diverse contents, making them more appealing as potential drug carriers. Compared with traditional synthetic nanoparticles, exosomes possess superior biocompatibility and much lower immunogenicity. This work reviewed the most up-to-date research progress of exosomes as carriers for nucleic acids, proteins and small molecule drugs for cancer and inflammation management. The drug loading strategies and potential cellular uptake behaviour of exosomes are highlighted, trying to provide reference for future exosome design and application.

Breakthrough of extracellular vesicles in pathogenesis, diagnosis and treatment of osteoarthritis

Osteoarthritis (OA) is a highly prevalent whole-joint disease that causes disability and pain and affects a patient's quality of life. However, currently, there is a lack of effective early diagnosis and treatment. Although stem cells can promote cartilage repair and treat OA, problems such as immune rejection and tumorigenicity persist. Extracellular vesicles (EVs) can transmit genetic information from donor cells and mediate intercellular communication, which is considered a functional paracrine factor of stem cells. Increasing evidences suggest that EVs may play an essential and complex role in the pathogenesis, diagnosis, and treatment of OA. Here, we introduced the role of EVs in OA progression by influencing inflammation, metabolism, and aging. Next, we discussed EVs from the blood, synovial fluid, and joint-related cells for diagnosis. Moreover, we outlined the potential of modified and unmodified EVs and their combination with biomaterials for OA therapy. Finally, we discuss the deficiencies and put forward the prospects and challenges related to the application of EVs in the field of OA.

Effects of urinary extracellular vesicles from prostate cancer patients on the transcriptomes of cancer-associated and normal fibroblasts

BACKGROUND

Increasing evidence suggests that cancer-derived extracellular vesicles (EVs) alter the phenotype and functions of fibroblasts and trigger the reprogramming of normal fibroblasts into cancer-associated fibroblasts (CAFs). Here, we for the first time studied the effects of urinary EVs from PC patients and healthy males on the transcriptional landscape of prostate CAFs and normal foreskin fibroblasts.

METHODS

Patient-derived prostate fibroblast primary cultures PCF-54 and PCF-55 were established from two specimens of PC tissues. EVs were isolated from urine samples of 3 patients with PC and 2 healthy males and used for the treatment of prostate fibroblast primary cultures and normal foreskin fibroblasts. The EV-treated fibroblasts were subjected to RNA sequencing analysis.

RESULTS

RNA sequencing analysis showed that the fibroblast cultures differed significantly in their response to urinary EVs. The transcriptional response of foreskin fibroblasts to the urinary EVs isolated from PC patients and healthy controls was very similar and mostly related to the normal functions of fibroblasts. On the contrary, PCF-54 cells responded very differently - EVs from PC patients elicited transcriptional changes related to the regulation of the cell division and chromosome segregation, whereas EVs from healthy males affected mitochondrial respiration. In PCF-55 cells, EVs from both, PC-patients and controls induced the expression of a number of chemokines such as CCL2, CCL13, CXCL1, CXCL8, whereas pathways related to regulation of apoptotic signaling and production of cell adhesion molecules were triggered specifically by EVs from PC patients.

CONCLUSION

This study demonstrates that urinary EVs from PC patients and healthy controls elicit distinct transcriptional responses in prostate CAFs and supports the idea that EVs contribute to the generation of functional heterogeneity of CAFs. Moreover, this study suggests that the changes in the gene expression pattern in EV recipient cells might serve as a novel type of functional cancer biomarkers.

Inhibition of lncRNA NEAT1 induces dysfunction of fibroblast-like synoviocytes in rheumatoid arthritis via miRNA-338-3p-mediated regulation of glutamine metabolism

Background

Rheumatoid arthritis (RA) is a systemic chronic autoimmune disease; cellular glutamine metabolism in fibroblast-like synoviocytes (FLSs) of RA was known to be essential for RA pathogenesis and progression. NEAT1, a long non-coding RNA, functions as an oncogene in diverse cancers. The exact roles and molecular mechanisms of NEAT1 in fibroblast-like synoviocytes (FLSs) of RA patients are unknown.

Methods

Expression of NEAT1 and miR-338-3p was measured by qRT-PCR. lncRNA-miRNA and miRNA-mRNA interactions were predicted from starBase and validated by RNA pull-down and luciferase assay. The glutamine metabolism of FLSs was evaluated by glutamine uptake and glutaminase activity. Cell death in FLSs in response to H₂O₂ was assessed by MTT and Annexin V assays.

Results

NEAT1 was significantly upregulated, and miR-338-3p was significantly downregulated in FLSs from RA patients compared to normal FLSs. Silencing of NEAT1 and overexpression of miR-338-3p suppressed glutamine metabolism in FLSs-RA and promoted H₂O₂-induced apoptosis. Bioinformatics analysis showed that NEAT1 sponges miR-338-3p to form competing endogenous RNA (ceRNAs), which was verified by RNA pull-down assay and luciferase assay FLSs-RA had an increased rate of glutamine metabolism compared to normal FLSs increased compared to normal FLSs. The results confirmed that GLS (Glutaminase), a key enzyme in glutamine metabolism, is a direct target of miR-338-3p in FLSs-RA. miR-338-3p inhibition of glutamine metabolism was verified by rescue experiments verified. Finally, restoration of miR-338-3p in FLSs-RA expressing NEAT1 overcomes NEAT1-promoted glutamine metabolism and resistance to apoptosis.

Conclusions

This study reveals the essential role and molecular targets of NEAT1-regulated glutamine metabolism and FLSs-RA dysfunction in fibroblast-like synoviocytes of RA and indicates that blocking the molecular pathway via non-coding RNAs may be beneficial for RA patients.

The Involvement of Neutrophils in the Pathophysiology and Treatment of Osteoarthritis

Osteoarthritis (OA) is a chronic disability that significantly impairs quality of life. OA is one of the most prevalent joint pathologies in the world, characterized by joint pain and stiffness due to the degeneration of articular cartilage and the remodeling of subchondral bone. OA pathogenesis is unique in that it involves simultaneous reparative and degradative mechanisms. Low-grade inflammation as opposed to high-grade allows for this coexistence. Previously, macrophages and T cells have been identified as playing major roles in the inflammation and destruction of OA joints, but recent studies have demonstrated that neutrophils also contribute to the pathogenesis. Neutrophils are the first immune cells to enter the synovium after joint injury, and neutrophilic activity is indispensably a requisite for the progression of OA. Neutrophils act through multiple mechanisms including tissue degeneration via neutrophil elastase (NE), osteophyte development, and the release of inflammatory cytokines and chemokines. As the actions of neutrophils in OA are discovered, the potential for novel therapeutic targets as well as diagnostic methods are revealed. The use of chondrogenic progenitor cells (CPCs), microRNAs, and exosomes are among the newest therapeutic advances in OA treatment, and this review reveals how they can be used to mitigate destructive neutrophil activity.

Cross-Tissue Analysis Using Machine Learning to Identify Novel Biomarkers for Knee Osteoarthritis

Background

Knee osteoarthritis (KOA) is a common degenerative joint disease. In this study, we aimed to identify new biomarkers of KOA to improve the accuracy of diagnosis and treatment.

Methods

GSE98918 and GSE51588 were downloaded from the Gene Expression Omnibus database as training sets, with a total of 74 samples. Gene differences were analyzed by Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway, and Disease Ontology enrichment analyses for the differentially expressed genes (DEGs), and GSEA enrichment analysis was carried out for the training gene set. Through least absolute shrinkage and selection operator regression analysis, the support vector machine recursive feature elimination algorithm, and gene expression screening, the range of DEGs was further reduced. Immune infiltration analysis was carried out, and the prediction results of the combined biomarker logistic regression model were verified with GSE55457.

Results

In total, 84 DEGs were identified through differential gene expression analysis. The five biomarkers that were screened further showed significant differences in cartilage, subchondral bone, and synovial tissue. The diagnostic accuracy of the model synthesized using five biomarkers through logistic regression was better than that of a single biomarker and significantly better than that of a single clinical trait.

Conclusions

CX3CR1, SLC7A5, ARL4C, TLR7, and MTHFD2 might be used as novel biomarkers to improve the accuracy of KOA disease diagnosis, monitor disease progression, and improve the efficacy of clinical treatment.

Exercise-Induced Extracellular Vesicles Delay the Progression of Prostate Cancer

Increasing evidence suggests that regular physical exercise not only reduces the risk of cancer but also improves functional capacity, treatment efficacy and disease outcome in cancer patients. At least partially, these effects are mediated by the secretome of the tissues responding to exercise. The secreted molecules can be released in a carrier-free form or enclosed into extracellular vesicles (EVs). Several recent studies have shown that EVs are actively released into circulation during physical exercise. Here, we for the first time investigated the effects of exercise-induced EVs on the progression of cancer in an F344 rat model of metastatic prostate cancer. Although we did not observe a consistent increase in the circulating EV levels, RNA sequencing analysis demonstrated substantial changes in the RNA content of EVs collected before and immediately after forced wheel running exercise as well as differences between EVs from runners at resting state and sedentary rats. The major RNA biotype in EVs was mRNA, followed by miRNA and rRNA. Molecular functions of differentially expressed RNAs reflected various physiological processes including protein folding, metabolism and regulation of immune responses triggered by the exercise in the parental cells. Intravenous administration of exercise-induced EVs into F344 rats with orthotopically injected syngeneic prostate cancer cells PLS10, demonstrated reduction of the primary tumor volume by 35% and possibly—attenuation of lung metastases. Hence, our data provide the first evidence that exercise-induced EVs may modulate tumor physiology and delay the progression of cancer.

Isolation of Microvesicles from Human Circulating Neutrophils

Neutrophil-derived microvesicles (NDMVs) are liberated by neutrophils upon cell activation by molecules. Once activated, neutrophils are primarily involved in acute inflammation; however, the microvesicles they produce are largely anti-inflammatory. NDMVs have been shown to protect cartilage during inflammatory arthritis. They exert these effects by inhibiting or affecting the function of target cells, including macrophages. NDMVs have the potential to act as disease-modifying agents, especially for inflammatory diseases. This protocol describes a method using differential centrifugation to separate neutrophils from whole human blood. Subsequently, neutrophils are identified by cytospin and Wright's staining, and then the NDMVs are isolated using differential centrifugation.