Therapeutic targets and potential delivery systems of melatonin in osteoarthritis.

Osteoarthritis (OA) is a highly prevalent age-related musculoskeletal disorder that typically results in chronic pain and disability. OA is a multifactorial disease, with increased oxidative stress, dysregulated inflammatory response, and impaired matrix metabolism contributing to its onset and progression. The neurohormone melatonin, primarily synthesized by the pineal gland, has emerged as a promising therapeutic agent for OA due to its potential to alleviate inflammation, oxidative stress, and chondrocyte death with minimal adverse effects. The present review provides a comprehensive summary of the current understanding regarding melatonin as a promising pharmaceutical agent for the treatment of OA, along with an exploration of various delivery systems that can be utilized for melatonin administration. These findings may provide novel therapeutic strategies and targets for inhibiting the advancement of OA.

Identification of EGFR as an essential regulator in chondrocytes ferroptosis of osteoarthritis using bioinformatics, in vivo, and in vitro study.

Objective: The mechanisms of chondrocytes ferroptosis in osteoarthritis (OA) have not yet been fully elucidated. This study aimed to identify key ferroptosis related genes (FRGs) involved in chondrocytes ferroptosis. Methods: LASSO, SVM-RFE, and receiver operating characteristic curve (ROC) were performed to screen key differentially expressed FRGs (DEFRGs). Functional analyses were conducted using GO, and KEGG analyses. Unsupervised clustering analysis was used to identify ferroptosis related patterns. The CeRNA network was constructed to predict the upstream miRNAs and lncRNAs. Finally, we validated the role of EGFR in chondrocytes ferroptosis using in vivo and in vitro experiments. Results: A total of 42 DEFRGs were identified between OA and normal cartilages. GO and KEGG analyses indicated that these DEFRGs were significantly engaged in ferroptosis related biological processes and pathways, such as cellular response to oxidative stress, positive regulation of programmed cell death, MAPK and PI3K-Akt signaling pathways. Moreover, four key DEFRGs, including ACSF2, AURKA, EGFR, and KLHL24, were considered as potential biomarkers of OA. Moreover, two distinct ferroptosis related patterns were determined, and a total of 882 differentially expressed genes were identified which might participate in extracellular matrix degradation and inflammatory response. In addition, the CeRNA network showed that EGFR could be competitively regulated by 3 lncRNAs and 4 miRNAs. Significantly, the expression of EGFR was downregulated in human OA cartilages, OA mouse model, and erastin induced chondrocytes. EGFR inhibition could induce the occurrence of chondrocytes ferroptosis and ECM degradation which could be reversed by the addition of Ferrostatin-1. Conclusion: Our study has identified ACSF2, AURKA, EGFR, and KLHL24 as ferroptosis-related biomarkers in OA. Furthermore, we have conducted a preliminary investigation into the role of EGFR in regulating chondrocytes ferroptosis. These findings offer novel insights into the molecular mechanisms underlying OA.

The Effects of an Osteoarthritic Joint Environment on ACL Damage and Degeneration: A Yucatan Miniature Pig Model.

Posttraumatic osteoarthritis (PTOA) arises secondary to joint injuries and is characteristically driven by inflammatory mediators. PTOA is often studied in the setting of ACL tears. However, a wide range of other injuries also lead to PTOA pathogenesis. The purpose of this study was to characterize the morphological changes in the uninjured ACL in a PTOA inflammatory environment. We retrospectively reviewed 14 ACLs from 13 Yucatan minipigs, 7 of which had undergone our modified intra-articular drilling (mIAD) procedure, which induced PTOA through inflammatory mediators. Seven ACLs were harvested from mIAD minipigs (PTOA) and seven ACLs from control minipigs with no cartilage degeneration (non-PTOA). ACL degeneration was evaluated using histological scoring systems. IL-1ß, NF-κB, and TNF-α mRNA expression in the synovium was measured using qRT-PCR. PTOA minipigs demonstrated significant ACL degeneration, marked by a disorganized extracellular matrix, increased vascularity, and changes in cellular shape, density, and alignment. Furthermore, IL-1ß, NF-κB, and TNF-α expression was elevated in the synovium of PTOA minipigs. These findings demonstrate the potential for ACL degeneration in a PTOA environment and emphasize the need for anti-inflammatory disease-modifying therapies following joint injury.

[Value of peripheral blood monocyte subsets and CD64 expression in the diagnosis and prognosis of sepsis].

OBJECTIVE: To explore the value of monocyte subsets and CD64 expression in the diagnosis and prognosis of sepsis. METHODS: A prospective case-control study was designed. 30 septic patients and 30 non-septic patients who were admitted to the intensive care unit (ICU) of the PLA Army Characteristic Medical Center from March 2021 to March 2022 were enrolled. After 1, 3, and 5 days of ICU admission, peripheral blood samples were taken from patients. Flow cytometry was used to detect the proportion of monocyte subsets and the expression level of CD64 on the surface, and the difference of expression between patients in two group was analyzed. The risk variables for sepsis were analyzed using single-factor and multi-factor Logistic regression. The diagnostic efficacy of each risk factor for sepsis was determined using the receiver operator characteristic curve (ROC curve). RESULTS: One day after ICU admission, the proportions of monocytes and classic monocytes in white blood cells (WBC) of septic patients were significantly lower than those of non-septic patients [proportion of monocytes to WBC: (4.13±2.03)% vs. (6.53±3.90)%, proportion of classic monocytes to WBC: 1.97 (1.43, 2.83)% vs. 3.37 (1.71, 5.98)%, both P < 0.05]. The proportion of non-classical monocytes in monocytes was significantly higher in septic patients than that in non-septic patients [(11.42±9.19)% vs. (6.57±4.23)%, P < 0.05]. The levels of CD64 expression in monocytes, classic monocytes, intermediate monocytes and non-classic monocytes were significantly higher in sepsis patients than those in non-septic patients [mean fluorescence intensity (MFI): 13.10±6.01 vs. 9.84±2.83 for monocytes, 13.58±5.98 vs. 10.03±2.84 for classic monocytes, 13.48±6.35 vs. 10.22±2.99 for intermediate monocytes, 8.21±5.52 vs. 5.79±2.67 for non-classic monocytes, all P < 0.05]. Multivariate Logistic regression research showed that CD64 in typical monocytes [odds ratio (OR) = 1.299, 95% confidence interval (95%CI) was 1.027-1.471, P = 0.025] and the proportion of non-typical monocytes in monocytes (OR = 1.348, 95%CI was 1.034-1.758, P = 0.027) were the independent risk factors for sepsis. ROC curve showed that the area under the ROC curve (AUC) of CD64 expression of classical monocytes, the fraction of non-classical monocytes in monocytes, and procalcitonin (PCT) in the diagnosis of sepsis was 0.871. A correlation analysis revealed a negative relationship between the acute physiology and chronic health status evaluation II (APACHE II) on the first, third, and fifth days following ICU admission and the expression level of CD64 in patients' classic monocytes (r values were -0.264, -0.428 and -0.368, respectively, all P < 0.05). CONCLUSIONS: Combining the proportion of non-classical monocytes in monocytes, the level of plasma PCT, and the CD64 expression of classic monocytes in peripheral blood has good efficacy in identifying sepsis and assessing its severity.

Exosomes from artesunate-treated bone marrow-derived mesenchymal stem cells transferring SNHG7 to promote osteogenesis via TAF15-RUNX2 pathway.

Aim: Effect of artesunate (ART)-treated bone marrow-derived mesenchymal stem cells-derived exosomes (BMSC-Exos) on osteogenesis and its underlying mechanisms were investigated. Materials & methods: Proliferation, alkaline phosphatase activity and calcified nodule formation of osteoblasts were determined. A mouse model of osteoporosis was established by ovariectomy. Results: SNHG7 was upregulated in BMSC-Exos by twofold, which was further enhanced in ART-BMSC-Exos by about twofold. ART intensified BMSC-Exos-induced proliferation, alkaline phosphatase activity by about fourfold, calcified nodule formation by about threefold and upregulation of osteogenesis related molecules RUNX2 (by 50%), BMP2 (by 30%) and ATF4 (by 40%) via delivering SNHG7. Mechanistically, SNHG7 recruited TAF15 to facilitate RUNX2 stability. Conclusion: ART-BMSC-Exos facilitated osteogenesis via delivering SNHG7 by modulating TAF15/RUNX2 axis.

Osteoporosis is the most common and complex skeletal disorder worldwide. Exosomes derived from bone marrow-derived mesenchymal stem cells (BMSC-Exos) have been recognized as an ideal seed source for bone tissue regeneration. We aimed to explore the effect of artesunate (ART)-BMSC-Exos on osteogenesis and its underlying mechanisms. The results showed that ART-BMSC derived exosomal SNHG7 facilitated osteoblast activity and attenuated osteogenesis in mice by modulating TAF15/RUNX2 pathway. Our findings contribute to a better understanding of the therapeutic mechanisms of ART-BMSCs-Exos for osteoporosis and suggest ART-BMSC-Exos as a novel therapeutic option for osteoporosis.

N6-methyladenosine Modification-Related Long Non-Coding RNAs are Potential Biomarkers for Predicting the Prognosis of Patients With Osteosarcoma.

Background: The role of N6-methyladenosine (m6A)-related long non-coding RNAs (lncRNAs) in osteosarcoma (OS) has not been fully studied yet. We aimed to identify m6A-related lncRNAs that could act as prognostic biomarkers for OS. Methods: Pearson correlation was performed to identify m6A-related lncRNAs. Univariate and multivariate Cox regression analyses were performed to construct the risk model and assess whether the risk score was an independent prognostic factor for patients with OS. Gene Set Enrichment Analysis (GSEA) was performed to analyze the functions of genes in high-risk and low-risk groups. StarBase and Cytoscape were used to construct a competing endogenous RNA (ceRNA) network based on m6A-related prognostic lncRNA signature. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to analyze the function of genes involved in the ceRNA network. Results: We extracted 122 common lncRNAs from TCGA and Gene Expression Omnibus (GEO) databases. Pearson correlation results revealed 59 significant m6A-related lncRNAs in The Cancer Genome Atlas (TCGA) database, from which 2 were screened to construct a risk signature in TCGA dataset, which was then validated in the GEO dataset. A corresponding risk score was calculated and shown to be an independent prognostic factor for patients with OS. Enrichment analysis indicated that cell proliferation-related biological processes were more common in the high-risk group, while immune-related biological processes were more common in the low-risk group. Moreover, we established a nomogram that had a good ability to predict the overall survival of patients with OS. Additionally, a ceRNA network based on small nucleolar RNA host gene 7 (SNHG7) and small nucleolar RNA host gene 12 (SNHG12) was constructed, with genes that were enriched in hepatocellular carcinoma, gastric cancer, and non-small-cell lung cancer pathways. Conclusion: Our study revealed the prognostic role of m6A-related lncRNAs in OS and identified SNHG7 and SNHG12 as potential biomarkers for predicting the prognosis of patients with OS. These findings have enriched our understanding of the role of m6A modification in the dysregulation of lncRNAs in OS.

Glycyrrhizin alleviates sepsis-induced acute respiratory distress syndrome via suppressing of HMGB1/TLR9 pathways and neutrophils extracellular traps formation.

BACKGROUND: Neutrophil extracellular traps (NETs) are involved in the development of sepsis-induced acute respiratory distress syndrome (ARDS). Glycyrrhizin (GL), the main active ingredient of the traditional Chinese medicine Glycyrrhiza glabra, has anti-inflammatory, anti-viral, and immunomodulatory effects. OBJECTIVE: The study aims to explore the efficacy and potential mechanism of GL on sepsis-induced ARDS in mice. MATERIALS AND METHODS: Mice were randomly divided into 3 groups: Control, CLP, and GL + CLP. Mice sepsis ARDS model was induced by cecal ligation and puncture (CLP) followed by intraperitoneal GL treatment. Then, the 7-day survival rate of mice was recorded. The lung function of mice was determined by whole-body plethysmography. Lung pathology and scores were observed by hematoxylin-eosin staining. The wet/dry ratio (W/D) of the lung was measured by weighing method. The protein concentration in bronchoalveolar lavage fluid (BALF) was measured by the BCA method. NETs formation in lung tissue was detected by immunofluorescence. Furthermore, HMGB1、TLR9、MyD88 and IL6 expression in lung tissue were detected by western blot and by quantitative real-time PCR, respectively. RESULTS: The results showed that GL improved the survival rate, attenuated lung tissue injury and reduced the expression of inflammatory factors in mice with CLP-induced sepsis. Meanwhile, we confirmed that GL could inhibit TLR9 / MyD88 activation from reducing NETs formation by decreasing HMGB1 expression. The formation of NETs is regulated by HMGB1 / TLR9 / MyD88. In addition, GL improved lung function in mice with sepsis-induced ARDS. Lung function suggested that GL increased alveolar ventilation, alleviated ventilator fatigue and reduced airway resistance in mice with ARDS induced by sepsis. CONCLUSIONS: GL ameliorated sepsis-induced ARDS and reduced the NETs formation in lung tissues, which may be associated with the inhibition of the HMGB1 / TLR9 pathway.

Exogenous growth hormone functionally alleviates glucocorticoid-induced longitudinal bone growth retardation in male rats by activating the Ihh/PTHrP signaling pathway.

Glucocorticoid (GC)-induced longitudinal bone growth retardation is a common and severe adverse effect in pediatric patients receiving GC immunosuppressive therapy. Molecular mechanisms underlying GC-induced growth inhibition are unclear. GC withdrawal following short-term high-dose use is common, including in the immediate post-transplant period. However, whether skeleton growth recovery is sufficient or whether growth-promoting therapy is required following GC withdrawal is unknown. The aim of this study was to investigate the effect of exogenous growth hormone (GH) on growth plate impairment in GC-induced longitudinal bone growth retardation. Here, apoptotic chondrocytes in the hypertrophic layer of growth plates increased whereas Indian Hedgehog (Ihh) and Parathyroid Hormone Related Peptide (PTHrP) protein levels in the growth plate decreased following GC exposure. The hypertrophic zone of the growth plate expanded following GC withdrawal. Subcutaneously injected GH penetrated the growth plate and modified its organization in rats following GC withdrawal. Ihh and PTHrP expression in GC-induced apoptotic chondrocytes decreased in vitro. GH promoted chondrocyte proliferation by activating Ihh/PTHrP signaling. Downregulating Ihh using specific siRNAs increased chondrocyte apoptosis and inhibited PTHrP, Sox9, and type II collagen (Col2a1) protein expression. GH inhibited apoptosis of Ihh-deficient growth plate chondrocytes by upregulating PTHrP, Sox9, and Col2a1 expression. Thus, reversal of the effect of GC on growth plate impairment following its withdrawal is insufficient, and exogenous GH provides growth plate chondral protection and improved longitudinal growth following GC withdrawal by acting on the Ihh/PTHrP pathway.

The Value of Interleukin-10 in the Early Diagnosis of Neonatal Sepsis: A Meta-Analysis.

OBJECTIVES: Interleukin-10 is a significant marker in neonatal sepsis. This meta-analysis evaluated the accuracy of interleukin-10 expression in the diagnosis of neonatal sepsis. DATA SOURCE: Summary of literature review. STUDY SELECTION: A literature search strategy was developed, including PubMed, EMBASE, Web of Science, MEDLINE, and the Cochrane Library. All publications published till October 1, 2020, were retrieved; the key words were "sepsis" and "interleukin-10." DATA EXTRACTION: The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were used to evaluate the data, and the heterogeneity of the combined results was tested according to the I2 value. DATA SYNTHESIS: A total of six articles involving 879 newborns were included in the study. The combined sensitivity was 0.82 (95% CI, 0.78-0.86), the specificity was 0.79 (95% CI, 0.75-0.82), the positive likelihood ratio was 4.17 (95% CI, 2.6-6.69), and the negative likelihood ratio was 0.25 (95% CI, 0.16-0.39). The area under the summary receiver operating characteristic curve was 0.88 (95% CI, 0.86-0.91), and the Q index was 0.81. The combined diagnostic odds ratio was 17.52 (95% CI, 8.95-34.29). CONCLUSIONS: Based on the results of the meta-analysis, interleukin-10 is a useful biomarker in the early diagnosis of neonatal sepsis. Its sensitivity, specificity, and diagnostic ability are excellent. However, it needs to be combined with clinical history data for comprehensive judgment and should not be used alone for diagnosis.

Development and prospective validation of a novel risk score for predicting the risk of lower extremity deep vein thrombosis among multiple trauma patients.

INTRODUCTION: Trauma patients have an increased risk of deep vein thrombosis (DVT). Early identification of patients with a high risk of DVT after trauma is crucial for thromboembolism prophylaxis. We aimed to develop and prospectively validate a novel risk score based on a nomogram to predict lower extremity DVT among multiple trauma patients. MATERIALS AND METHODS: Clinical data were collected from 281 multiple trauma patients who were admitted to our trauma center within 24 h of admission from January 2016 to September 2019 to develop a novel DVT risk score. The DVT risk estimates were then calculated prospectively based on the score in a new study cohort from October 2019 to July 2020. The technique of least absolute shrinkage and selection operator (LASSO) was used to select variables for the early prediction of DVT in multiple trauma patients. The DVT risk assessment score (DRAS) was constructed by incorporating related features based on the LASSO analysis and nomogram prediction model. Further, the multiple trauma patients were divided into various risk groups according to the DRAS. The incidence of lower extremity DVT was compared between groups and the discrimination of the DRAS was assessed using the area under the curve (AUC). RESULTS: Based on the LASSO method, seven variables (age, injury severity score, body mass index, lower extremity fracture, D-dimer level, fibrin degradation products, and prothrombin time) were included in the DRAS. A total of 166 multiple trauma patients were enrolled in the prospective study. Increased risk of DVT after trauma was related to higher DRAS. The area under the receiver operating characteristic (ROC) curve for the DRAS was 0.890 (0.841-0.940) in the validation cohort. Moreover, the discriminatory capacity of the DRAS was superior to that of each variable independently and the TESS score (P < 0.05). CONCLUSIONS: We developed and prospectively validated the DRAS as a reliable tool for predicting the risk of lower extremity DVT among patients with multiple trauma. This may help guide trauma surgeons in making sound decisions in the administration of DVT prophylaxis.

Long non-coding RNA MEG3 is involved in osteogenic differentiation and bone diseases (Review).

Osteogenic differentiation originating from mesenchymal stem cells (MSCs) requires tight co-ordination of transcriptional factors, signaling pathways and biomechanical cues. Dysregulation of such reciprocal networks may influence the proliferation and apoptosis of MSCs and osteoblasts, thereby impairing bone metabolism and homeostasis. An increasing number of studies have shown that long non-coding (lnc)RNAs are involved in osteogenic differentiation and thus serve an important role in the initiation, development, and progression of bone diseases such as tumors, osteoarthritis and osteoporosis. It has been reported that the lncRNA, maternally expressed gene 3 (MEG3), regulates osteogenic differentiation of multiple MSCs and also acts as a critical mediator in the development of bone formation and associated diseases. In the present review, the proposed mechanisms underlying the roles of MEG3 in osteogenic differentiation and its potential effects on bone diseases are discussed. These discussions may help elucidate the roles of MEG3 in osteogenic differentiation and highlight potential biomarkers and therapeutic targets for the treatment of bone diseases.

Long non-coding RNA MALAT1 as a valuable biomarker for prognosis in osteosarcoma: A systematic review and meta-analysis.

BACKGROUND: Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (lncRNA, MALAT1) has been found to be aberrantly expressed in osteosarcoma, while high MALAT1 expression is correlated with both metastasis and prognosis. This meta-analysis set out to investigate the prognostic value of lncRNA MALAT1 in patients living with osteosarcoma. METHODS: We conducted a systematical search of available databases from inception to May 2019. Odds ratios (OR) of clinical parameters, as well as hazard ratio (HR) of overall survival (OS), were calculated in order to evaluate the relationship between MALAT1 expression and the prognosis of patients living with osteosarcoma. RESULTS: Nine eligible studies which included a total of 599 osteosarcoma patients were enrolled in the present study. Pooled results found that high MALAT1 expression was associated with clinical stage and distant metastasis, but not age, gender, tumor anatomical location or tumor size. When compared to patients with low MALAT1 expression, patients with high MALAT1 expression were markedly correlated with a worse OS. Moreover, MALAT1 may be an independent predictive factor for OS in patients living with osteosarcoma. CONCLUSIONS: This meta-analysis suggests that high MALAT1 expression is associated with advanced clinicopathological features as well as unfavorable prognosis. LncRNA MALAT1 has the potential to serve as a moderate prognostic biomarker for osteosarcoma.

Emerging roles of long noncoding RNA in chondrogenesis, osteogenesis, and osteoarthritis.

Osteoarthritis (OA) is the most prevalent age-related debilitating joint disease, and is characterized primarily by articular cartilage degradation and subchondral bone lesions. It is also the leading cause of chronic morbidity in older populations. The etiology of OA is multifactorial, with the underlying regulatory mechanisms remaining largely unknown. Long noncoding RNA (lncRNA) is a group of noncoding RNAs defined as being >200 nucleotides in length. Increasing evidence demonstrates that many lncRNAs serve as critical regulators of chondrogenesis and bone and cartilage homeostasis, thereby influencing OA development. In this review, we highlight the current understanding concerning lncRNAs, including their physical features, biological functions, and potential roles in chondrogenesis, osteogenesis, and OA. This information may shed new light on the epigenetic regulation of cartilage and substantiate lncRNAs as novel therapeutic targets in OA.