METTL14 Mediates Glut3 m6A methylation to improve osteogenesis under oxidative stress condition

OBJECTIVES

Bone remodeling imbalance contributes to osteoporosis. Though current medications enhance osteoblast involvement in bone formation, the underlying pathways remain unclear. This study was aimed to explore the pathways involved in bone formation by osteoblasts, we investigate the protective role of glycolysis and N6-methyladenosine methylation (m6A) against oxidative stress-induced impairment of osteogenesis in MC3T3-E1 cells.

METHODS

We utilized a concentration of 200 μM hydrogen peroxide (H2O2) to establish an oxidative damage model of MC3T3-E1 cells. Subsequently, we examined the alterations in the m6A methyltransferases (METTL3, METTL14), glucose transporter proteins (GLUT1, GLUT3) and validated m6A methyltransferase overexpression in vitro and in an osteoporosis model. The osteoblast differentiation and osteogenesis-related molecules and serum bone resorption markers were measured by biochemical analysis, Alizarin Red S staining, Western blot and ELISA.

RESULTS

H2O2 treatment inhibited glycolysis and osteoblast differentiation in MC3T3-E1 cells. However, when METTL14 was overexpressed, these changes induced by H2O2 could be mitigated. Our findings indicate that METTL14 promotes GLUT3 expression via YTHDF1, leading to the modulation of various parameters in the H2O2-induced model. Similar positive effects of METTL14 on osteogenesis were observed in an ovariectomized mouse osteoporosis model.

DISCUSSION

METTL14 could serve as a potential therapeutic approach for enhancing osteoporosis treatment.

Role of insulinemic and inflammatory dietary patterns on gut microbial composition and circulating biomarkers of metabolic health among older American men

Chronic low-grade inflammation and hyperinsulinemia are linked with metabolic dysfunction and dysbiosis. This study investigated the role of dietary inflammatory and insulinemic potential on gut microbiome and circulating health biomarkers in older men. Data from the Osteoporotic Fractures in Men (MrOS) study were analyzed. Reversed Empirical Dietary Inflammatory Pattern (rEDIP), Empirical Dietary Index for Hyperinsulinemia (rEDIH), and Healthy Eating Index (HEI)-2020 scores were computed from food frequency questionnaire data. Stool samples were profiled using 16S rRNA sequencing. Elastic net regression identified diet-associated microbial profiles and multivariable-adjusted linear regression assessed diet-biomarker associations. Higher rEDIP, rEDIH, and HEI-2020 scores were positively associated with gut microbiota alpha diversity. Specific genera, including Intestinibacter and Lachnospira, associated positively, while Dielma, Peptococcus, Feacalitalea, and Negativibaccilus associated inversely with healthier dietary patterns. When evaluating changes in dietary patterns between baseline and visit 4 ( ~ 14 years), these genera tended to define rEDIP, rEDIH more than HEI-2020. In addition, higher dietary quality was linked to better biomarker profiles, including lower creatinine, sodium, triglycerides, and insulin resistance. Beneficial effects of higher dietary quality on health may be mediated by the ability of diet to regulate gut microbial composition and metabolic biomarker profiles.

Moderate-severe aortic arch calcification and high serum alkaline phosphatase co-modify the risk of cardiovascular events and mortality among chronic hemodialysis patients

BACKGROUND

Patients with end-stage kidney disease undergoing chronic hemodialysis (HD) have an unparalleled risk of vascular calcification (VC) and high alkaline phosphatase (Alk-P) levels. However, whether VC contributed to the cardiovascular risk modified by serum Alk-P levels was not addressed in the population.

METHODS

A retrospective cohort study was conducted on chronic HD patients, between October 1 and December 31, 2018, with aortic arch calcification (AoAC) scores and serum Alk-P levels. Patients were categorized into four groups: non-to-mild AoAC/low Alk-P, non-to-mild AoAC/high Alk-P, moderate-to-severe AoAC/low Alk-P, and moderate-to-severe AoAC/high Alk-P. The Cox proportional hazard model and Kaplan-Meier analysis were used to evaluate the risks of major adverse cardiovascular effects (MACEs) and cardiovascular and all-cause mortality after multivariate adjustment.

RESULTS

Among 376 chronic HD patients recruited, 125 (33%) had non-to-mild AoAC/low Alk-P, 76 (20%) had non-to-mild AoAC/high Alk-P, 89 (24%) had moderate-to-severe AoAC/low Alk-P, and 86 (23%) had moderate-to-severe AoAC/high Alk-P. After 3 years of follow-up, patients with coexisting moderate-to-severe AoAC and high Alk-P had a higher risk of MACEs (aHR 1.76; 95% CI 1.06-2.92), and cardiovascular (aHR 2.49; 95% CI 1.21-5.11) and all-cause mortality (aHR 2.67; 95% CI 1.39-5.13) compared to those with non-to-mild AoAC/low Alk-P even after adjustments for significant clinical variables.

CONCLUSIONS

In chronic HD patients, moderate to severe AoAC co-existed with high Alk-P levels and enhanced the risk of MACEs and cardiovascular and all-cause mortality. Interventions to attenuate these risk factors simultaneously should be emphasized in this population.

Therapeutic potential of SOX family transcription factors in osteoarthritis

BACKGROUND

As the worldwide population ages, osteoarthritis has significantly increased. This musculoskeletal condition has become a pressing global health issue and thus, prevention and treatment of osteoarthritis have become the primary focus of domestic and international research. Scholarly investigations of the molecular mechanisms that are related to the occurrence and development of osteoarthritis have shed light on the pathological causes of this condition to a certain extent, providing a foundation for its prevention and treatment. However, further research is necessary to fully understand the critical role of the transcription factor SOX9 in chondrocyte differentiation and the development of osteoarthritis. As a result, there has been widespread interest in SOX transcription factors. While SOX9 has been utilized as a biomarker to indicate the occurrence and prognosis of osteoarthritis, investigations into other members of the SOX family and the development of targeted treatments around SOX9 are still required.

PURPOSE

This article considers the impact of the SOX protein on the development and inhibition of osteoarthritis and highlights the need for therapeutic approaches targeting SOX9, as supported by existing research.

RESULTS

SOX9 can contribute to the process of osteoarthritis through acetylation and ubiquitination modifications. The regulation of the WNT signalling pathway, Nrf2/ARE signalling pathway, NF-κB signalling pathway and SOX9 is implicated in the emergence of osteoarthritis. Non-coding RNA may play a role in the onset and progression of osteoarthritis by modulating various SOX family members, including SOX2, SOX4, SOX5, SOX6, SOX8, SOX9 and SOX11.

CONCLUSION

SOX9 has the capability of mitigating the onset and progression of osteoarthritis through means such as medication therapy, stem cell therapy, recombinant adeno-associated virus (rAAV) vector therapy, physical therapy and other approaches.

Myeloperoxidase as a therapeutic target for oxidative damage in Alzheimer's disease

Alzheimer's disease (AD) is a major neurodegenerative disorder more common in older adults. One of the leading AD hypotheses involves the amyloid beta (A) production, it is associated to oxidative stress, neuroinflammation, and neurovascular damage. The interaction of A with the blood vessel wall contributes to the disruption of the blood-brain barrier (BBB), allowing neutrophil infiltration containing the myeloperoxidase enzyme (MPO), which produces hypochlorous acid (HOCl) a potent oxidant. Also, MPO could be released from the microglia cells and interact with the amyloid beta plaques. This review aims to study the role of MPO in the progression of AD, in particular its contribution to oxidative stress and neuroinflammation. Furthermore, to explore the MPO-potential as AD-biomarker to evaluate the therapeutic potential of its inhibitors to mitigate the neurotoxicity. Finally, revise MPO inhibitors that could act as dual inhibitors acting on MPO and acetylcholinesterase and or another target involved in AD.

The impact of low energy availability risk on pre-competition physiological function in Chinese female combat athletes

BACKGROUND

Low energy availability (LEA) can negatively impact athletes' physiological function and performance. This study aims to examine the prevalence of LEA in Chinese female combat athletes and monitor changes in physiological function and performance during the pre-competition period.

METHOD

We assessed the incidence of low energy availability (LEA) and eating disorder (ED) risks in 84 female combat athletes (judo, freestyle wrestling, and sanda) from Beijing using the Low Energy Availability in Females Questionnaire (LEAF-Q) and the Eating Disorder Examination Questionnaire (EDE-Q). From this group, 11 judo athletes who were preparing for competition were selected and divided into a low energy availability (LEA) group and a non-LEA group based on their energy availability levels. Dietary intake, training energy expenditure, body composition, resting metabolic rate, blood markers, and special judo fitness tests were monitored at 4 weeks, 2 weeks, and 0 weeks before the competition.

RESULTS

Among the 84 athletes, 45.2% of athletes (n = 38) were at increased risk of LEA, and 21.4% of athletes (n = 18) were classified as high in eating disorder risk. There were no significant differences in LEA and ED risk between elite and recreational athletes. Among the 11 athletes preparing for competition, 6 athletes (45.5%) were in a state of LEA at the initial stage (4 weeks before the competition), and by the competition week, all 11 athletes exhibited LEA. Additionally, athletes in the LEA group experienced significant reductions in VO2 and resting metabolic rate at 0 week of the competition compared to 4 weeks prior (p < 0.05). Thyroid function indicators and IGF-1 levels of LEA group also significantly decreased (p < 0.05). After completing the four-week pre-competition weight loss, heart rate recovery during the special judo fitness test improved significantly in both the LEA and non-LEA groups (p < 0.05).

CONCLUSION

The current study identified a risk of LEA among Chinese female combat sport athletes, with no significant difference in the prevalence of LEA between elite and recreational athletes. It is essential for Chinese coaches and sports medicine staff to implement LEA-related nutritional education across all performance levels. Moreover, preventive measures during training are recommended to mitigate the impact of LEA on physiological function during the pre-competition weight loss phase.

Finite element models of intervertebral disc: recent advances and prospects

OBJECTIVES

The incidence rate of intervertebral disc degeneration (IVDD) is increasing year by year, which brings great harm to our health. The change of biomechanical factors is an important reason for IVDD. Therefore, more and more studies use finite element (FE) models to analyze the biomechanics of spine.

METHODS

In this review, literatures which reported the FE model of intervertebral disc (IVD) were reviewed. We summarized the types and constructional methods of the FE models and analyzed the applications of some representative FE models.

RESULTS

The most widely used model was the nonlinear model which considers the behavior of porous elastic materials. As more advanced methods, More and more models which involve penetration parameters were used to simulate the biological behavior and biomechanical properties of IVD.

CONCLUSIONS

Personalized modeling should be carried out in order to better provide accurate basis for the diagnosis and treatment of the disease. In addition, microstructure, cell behavior and complex load should be considered in the process of model construction to build a more realistic model.

Gut microbiota and microbial metabolites for osteoporosis

Osteoporosis is an age-related bone metabolic disease. As an essential endocrine organ, the skeletal system is intricately connected with extraosseous organs. The crosstalk between bones and other organs supports this view. In recent years, the link between the gut microecology and bone metabolism has become an important research topic, both in preclinical studies and in clinical trials. Many studies have shown that skeletal changes are accompanied by changes in the composition and structure of the gut microbiota (GM). At the same time, natural or artificial interventions targeting the GM can subsequently affect bone metabolism. Moreover, microbiome-related metabolites may have important effects on bone metabolism. We aim to review the relationships among the GM, microbial metabolites, and bone metabolism and to summarize the potential mechanisms involved and the theory of the gut‒bone axis. We also describe existing bottlenecks in laboratory studies, as well as existing challenges in clinical settings, and propose possible future research directions.

Causal associations of metabolic dysfunction-associated steatotic liver disease with gestational hypertension and preeclampsia: a two-sample Mendelian randomization study

BACKGROUND

Hypertensive disorders of pregnancy (HDPs), which include gestational hypertension (GH) and preeclampsia (PE), are the primary causes of maternal morbidity and mortality worldwide. Recent studies have found a correlation between metabolic dysfunction-associated steatotic liver disease (MASLD) and HDPs, but the causality of this association remains to be identified. Therefore, this study aims to evaluate the causal relationship between MASLD and HDPs through Mendelian randomization (MR) analysis.

METHODS

The summary statistics from genome-wide association studies were employed to conduct a two-sample MR analysis. Five complementary MR methods, including inverse variance weighting (IVW), MR-Egger, weighted median, simple mode and weighted mode were performed to assess the causality of MASLD on GH and PE. Furthermore, we conducted various sensitivity analyses to ensure the stability and reliability of the results.

RESULTS

Genetically predicted MASLD significantly increased the risk of GH (IVW: OR = 1.138, 95% CI: 1.062-1.220, p < 0.001), while there was little evidence of a causal relationship between MASLD and PE (IVW: OR = 0.980, 95% CI: 0.910-1.056, p = 0.594). The sensitivity analyses indicated no presence of heterogeneity and horizontal pleiotropy.

CONCLUSION

This MR study provided evidence supporting the causal effect of MASLD on GH. Our findings underscore the significance of providing more intensive prenatal care and early intervention for pregnant women with MASLD to prevent potential adverse obstetric outcomes.

Bioinformatic identification of important roles of COL1A1 and TNFRSF12A in cartilage injury and osteoporosis

OBJECTIVE

The aim of this study was to identify the key regulatory mechanisms of cartilage injury and osteoporosis through bioinformatics methods, and to provide a new theoretical basis and molecular targets for the diagnosis and treatment of the disease.

METHODS

Microarray data for cartilage injury (GSE129147) and osteoporosis (GSE230665) were first downloaded from the GEO database. Differential expression analysis was applied to identify genes that were significantly up-or down-regulated in the cartilage injury and osteoporosis samples. These genes were subjected to GO enrichment analysis and KEGG pathway analysis. In addition, we employed SVA and RRA methods to merge the two sets of data, eliminating batch effects and enhancing the statistical power of the analysis. Through WGCNA, we identified gene modules that were closely associated with disease phenotypes and then screened for key genes that intersected with differentially expressed genes. The diagnostic value of these genes as potential biomarkers was evaluated by ROC analysis. Moreover, we performed an immune infiltration analysis to explore the correlation between these core genes and immune cell infiltration.

RESULTS

We performed GO enrichment analysis and KEGG pathway analysis of genes significantly up-or down-regulated in cartilage injury and osteoporosis samples. Important biological processes, cellular components and molecular functions, and key metabolic or signaling pathways associated with osteoporosis and cartilage injury were identified. Through WGCNA, we identified gene modules that were closely associated with the disease phenotype, from which we then screened for key genes that intersected with differentially expressed genes. Ultimately, we focused on two identified core genes, COL1A1 and TNFRSF12A, and assessed the diagnostic value of these genes as potential biomarkers by ROC analysis. Meanwhile, GSVA provided an in-depth view of the role of these genes in disease-specific biological pathways. Immune infiltration analysis further revealed the possible key role of COL1A1 and TNFRSF12A in regulating immune cell infiltration in osteoporosis and cartilage injury.

CONCLUSION

COL1A1 and TNFRSF12A as key regulatory molecules in osteoporosis and cartilage injury.

Unveiling the ageing-related genes in diagnosing osteoarthritis with metabolic syndrome by integrated bioinformatics analysis and machine learning

Ageing significantly contributes to osteoarthritis (OA) and metabolic syndrome (MetS) pathogenesis, yet the underlying mechanisms remain unknown. This study aimed to identify ageing-related biomarkers in OA patients with MetS. OA and MetS datasets and ageing-related genes (ARGs) were retrieved from public databases. The limma package was used to identify differentially expressed genes (DEGs), and weighted gene coexpression network analysis (WGCNA) screened gene modules, and machine learning algorithms, such as random forest (RF), support vector machine (SVM), generalised linear model (GLM), and extreme gradient boosting (XGB), were employed. The nomogram and receiver operating characteristic (ROC) curve assess the diagnostic value, and CIBERSORT analysed immune cell infiltration. We identified 20 intersecting genes among DEGs of OA, key module genes of MetS, and ARGs. By comparing the accuracy of the four machine learning models for disease prediction, the SVM model, which includes CEBPB, PTEN, ARPC1B, PIK3R1, and CDC42, was selected. These hub ARGs not only demonstrated strong diagnostic values based on nomogram data but also exhibited a significant correlation with immune cell infiltration. Building on these findings, we have identified five hub ARGs that are associated with immune cell infiltration and have constructed a nomogram aimed at early diagnosing OA patients with MetS.

Exploring NamiRNA networks and time-series gene expression in osteogenic differentiation of adipose-derived stem cells

BACKGROUND

Adipose-derived stem cells (ADSCs) are a type of stem cell found in adipose tissue with the capacity to differentiate into multiple lineages, including osteoblasts. The differentiation of ADSCs into osteoblasts underlies osteogenic and pathological cellular basis in osteoporosis, bone damage and repair.

METHODS

Focused on ADSCs osteogenic differentiation, we conducted mRNA, microRNA expression and bioinformatics analysis, including gene differential expression, time series-based trend analysis, functional enrichment, and generates potential nuclear activating miRNAs (NamiRNA) regulatory network. The screened mRNAs in NamiRNA regulatory network were validated with correlation analysis.

RESULTS

The NamiRNA Regulatory Network reveals 4 mRNAs (C12orf61, MIR31HG, NFE2L1, and PCYOX1L) significantly downregulated in differentiated group and may be associated with ADSCs stemness. Furthermore, the significantly upregulated 10 genes (ACTA2, TAGLN, LY6E, IFITM3, NGFRAP1, TCEAL4, ATP5C1, CAV1, RPSA, and KDELR3) were significantly enriched in osteogenic-related pathways, and negatively correlated with ADSCs cell stemness in vitro.

CONCLUSION

These findings uncover potential genes related to ADSCs osteogenic differentiation, and provide theoretical basis for underlying ADSCs osteogenic differentiation and related diseases.

Risk factors for periprosthetic femoral fractures following hip arthroplasty: a systematic review and meta-analysis

INTRODUCTION

Periprosthetic femoral fracture (PPFF) is a serious complication following hip arthroplasty. The objective of this study was to determine the risk factors for PPFF following hip arthroplasty from existing studies.

METHODS

A comprehensive systematic search was performed in 4 databases: Pubmed, Embase, Web of Science, and Cochrane Library. The last search was carried out on 26th July 2024. We focused on identifying risk factors for PPFF following hip arthroplasty. Study eligibility required PPFF as an outcome and reporting of associated risk factors. Quality assessment was performed using the Newcastle-Ottawa Scale (NOS), with evidence certainty evaluated via Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Meta-analyses employed both fixed-effect and random-effects models to pool odds ratios for identified risk factors.

RESULTS

Out of 1553 articles, 36 studies published between 2006 and 2024 were included. Risk factors associated with increased incidence of PPFF ranges from very Low to High. High-quality evidence supported the use of uncemented stems (Odds Ratio [OR]: 3.36, 95% Confidence Interval [95% CI]: 3.02-3.74), major teaching hospital (OR: 2.04, 95% CI: 1.37-3.05). Moderate-quality evidence: female gender (OR: 1.60, 95% CI: 1.43-1.78), morbid obesity (OR: 1.44, 95% CI: 1.01-2.16), higher Deyo-Charlson index (OR: 1.44, 95% CI: 1.18-1.77), rheumatoid arthritis (OR: 1.89, 95% CI: 1.16-3.06), femoral Dorr type C (OR: 4.23, 95% CI: 2.82-6.33). Low evidence: age > 70 years (OR: 1.67, 95% CI: 1.19-2.34), revision hip arthroplasty (OR: 2.60, 95% CI: 1.59-4.27). BMI > 30 and history of hip surgery are not the risk (very low). Diagonized as osteoarthritis before surgery is a protective factor (OR:0.51, 95%CI: 0.40-0.65, quality = High).

CONCLUSION

This meta-analysis provided some low-to-high evidence about the risk of PPFF following hip arthroplasty. It's recommended that clinicians consider these risk factors when evaluating patients for hip arthroplasty and take steps to mitigate their impact, like optimizing patients health preoperatively, using cemented stems, and monitoring high-risk patients closely.

Radical Resection of Differentiated Thyroid Cancer in Elderly Patients: Evaluation of the Efficacy of the Immunocolloidal Gold Strip Method Combined with Nanocarbon Negative Imaging Tracing Technology for Parathyroid Gland Imaging

OBJECTIVE

Extant imaging methods used for the proper identification of the parathyroid glands to prevent post-operative hypothyroidism associated with the resection of differentiated thyroid cancer (DTC) are limited by factors such as low specificity, high cost, and technical complexity. This study, therefore, sought to investigate the efficacy of the immunocolloidal gold strip method combined with nanocarbon negative imaging tracing technology for parathyroid gland imaging during radical resection of DTC in elderly patients.

METHODS

A total of 100 elderly patients with DTC were enrolled and randomly divided into two groups: the control group and the observation group. The control group underwent conventional radical thyroidectomy with bilateral cervical lymph node dissection, while the observation group received the immunocolloidal gold strip method combined with nanocarbon negative imaging tracing technology for parathyroid gland imaging during the surgery. The baseline characteristics, intraoperative findings, postoperative parathyroid hormone (PTH), and serum calcium levels, as well as postoperative complications, were compared between the two groups.

RESULTS

There were no significant differences in age, gender, body mass index, comorbidities, or smoking history between the two groups. The observation group had a significantly higher number of parathyroid glands identified during surgery compared with the control group. The postoperative PTH and serum calcium levels at postoperative days 1 and 3 and at 6 months were significantly higher in the observation group than those in the control group. The incidence of postoperative hypoparathyroidism was significantly lower in the observation group.

CONCLUSION

The immunocolloidal gold strip method combined with nanocarbon negative imaging tracing technology is effective in identifying and preserving parathyroid glands during radical resection of DTC in elderly patients.

MS-275 facilitates osseointegration in osteoporotic rats by mitigating oxidative stress via activation of the miR-200a/Keap1/Nrf2 signaling pathway

OBJECTIVES

Osteoporosis, a prevalent metabolic bone disease affecting millions worldwide. Although MS-275 has been reported to inhibit oxidative stress, its ability to protect osteoblasts from oxidative stress damage has yet to be clarified. This study investigated whether MS-275 can inhibit oxidative stress and promote osteogenesis by activating the miRNA-200a/Keap1/Nrf2 signaling pathway.

METHODS

In vitro, MC3T3-E1 cells underwent induction with carbonyl cyanide 3-chlorophenylhydrazone, leading to the establishment of an oxidative stress model, investigating the underlying mechanism. In vivo, using a rat model of ovariectomized osteoporosis, evaluating the effects of MS-275.

RESULTS

In vitro, MS-275 treatment of oxidation-induced MC3T3-E1 cells resulted in up-regulation of osteoblast protein, increased expression of miRNA-200a, increased binding of miRNA-200a to Keap1 mRNA, decreased expression of Keap1 protein, and dissociation of Nrf2 from Keap1. The expressions of total Nrf2, nuclear Nrf2 and HO-1 were increased, mitochondrial function was enhanced, and oxidative damage was reduced. However, these effects were reversed after interference with miRNA-200a. In vivo,MS-275 effectively enhanced the microstructural features of distal femoral trabecular bone, increased the mineralization capacity of osteoblasts, and promoted bone formation.

DISCUSSION

MS-275 can reverse oxidative stress-induced cell damage, promote bone healing, and improve osteoporosis by activating the miRNA-200a/Keap1/Nrf2 pathway.

Study on immortalization of Mongolian sheep fibroblast cells

This study aims to establish an immortalized fibroblast cell line from Mongolian sheep. Primary Mongolian sheep fibroblasts (SSF) were isolated using tissue explant and enzymatic digestion methods, followed by microscopic observation, growth curve plotting, and karyotype analysis. The results confirmed the successful isolation of SSF. Human (hTERT) and sheep (sTERT) telomerase reverse transcriptase vectors were separately introduced into SSF, with cells passaged up to 36 generations following G418 selection. Microscopic examination and qRT-PCR results demonstrated that TERT transfection did not alter the morphology of SSF and led to stable, high levels of TERT expression (P < 0.01). Cell counting and flow cytometry revealed that TERT-transfected cells had higher viability and lower apoptosis rates compared to SSF (P < 0.05). Karyotype and soft agar colony formation assays indicated that hTERT and sTERT-transfected cells maintained normal characteristics without malignant transformation. β-galactosidase staining indicated that TERT transfection significantly reduced cellular senescence (P < 0.001). Additionally, sTERT-transfected cells exhibited higher TERT expression, enhanced viability, proliferation, and anti-senescence effects compared to hTERT-transfected cells (P < 0.05). In summary, the introduction of hTERT and sTERT effectively extends the lifespan of SSF, with sTERT demonstrating a more pronounced effect. This study provides critical evidence for preserving Mongolian sheep genetic resources and developing immortalized cell lines.

Sociodemographic variables are rarely included in femoral neck fracture randomized controlled trials: A systematic review

Introduction

Sociodemographic factors may affect outcomes after surgery for patients with femoral neck fractures. The purpose of this study was to assess the inclusion of sociodemographic variables in high-impact randomized controlled trials (RCTs) related to femoral neck fracture operative management.

Methods

PubMed, Embase, and Medline were queried from January 1, 2017 to March 31, 2024 for RCTs pertaining to operative treatment of femoral neck fracture patients in high impact journals were included. The journal of publication, year of publication, and interventions assessed by the RCTs were extracted. Each RCT was assessed for inclusion of the following sociodemographic variables: age, sex/gender, body mass index (BMI)/weight, race/ethnicity, education level, insurance, smoking/tobacco use, socioeconomic status, marital status, alcohol use, English proficiency, geographic measures (i.e. proximity to hospital), employment status, and prefracture residence status. Temporal reporting trends were analyzed using Chi-square test.

Results

Of 1038 RCTs identified, 37 were included for analysis. All 37 studies reported age and sex/gender. BMI/weight was reported in 22 studies (59.5 %). Patients' prefracture residence status was reported in 11 studies (29.7 %). Smoking/tobacco use was reported in 9 studies (24.3 %). Race/ethnicity was reported in only 5 studies (13.5 %). Socioeconomic status, English proficiency, geographic measures, marital status, education level, insurance, and employment variables were all reported in less than 10 % of the analyzed RCTs. Furthermore, there was no significant difference in the proportion of studies reporting at least one sociodemographic variable (excluding age, sex/gender, and BMI/weight) in 2017-2020 (10/22) versus 2021-2024 (8/15; p = 0.743).

Conclusion

Our analysis of high-impact RCTs revealed a large gap in the reporting of sociodemographic variables. RCTs relating to femoral neck fracture management should consistently report key sociodemographic variables to ensure generalizability of study findings.

Level of evidence

1.

Metal-free antioxidant nanozyme incorporating bioactive hydrogel as an antioxidant scaffold for accelerating bone reconstruction

Oxidative stress at bone defect sites mediates inflammation and even osteoblast apoptosis, severely hindering the repair process. While current antioxidant bone tissue engineering (BTE) scaffolds lack broad-spectrum reactive oxygen species (ROS) scavenging capability and structure-activity elucidation. Herein, we report a three-dimensional nitrogen-doped carbon antioxidant nanozyme (ZIFC) derived from metal-organic frameworks, which exhibits cascading superoxide dismutase- and catalase-like activities, along with the ability to scavenge other harmful free radicals. Through the experimental studies and theoretical calculations, we reveal that the catalase-like activity arises from the synergistic catalytic interaction between graphitized pyridinic nitrogen and its adjacent carbon atom. Moreover, hybrid double network hydrogel integrated with ZIFC is utilized to construct composite scaffold (Gel/ZIFC) by 3D printing. In vivo transcriptome analysis confirms that Gel/ZIFC can rapidly activate antioxidant defense system and suppress local inflammation under oxidative stress microenvironment, thereby protecting cells from oxidative damage. Subsequently, owing to the unique osteoinductive property of carbon nanomaterials and the osteoconductive property of 3D-printed scaffold, Gel/ZIFC composite scaffold exhibits desirable bone repair efficacy. The elucidation of structure-activity relationship and therapeutic mechanism provides new insights and guidance for devising antioxidant BTE scaffolds, and demonstrates their feasibility for clinical application.

Novel "hot spring"-mimetic scaffolds for sequential neurovascular network reconstruction and osteoporosis reversion

Neurovascular network damage and excessive hydrogen peroxide (H2O2) accumulation are the main obstacles for osteoporotic bone defect repair. It is extremely essential to endow the implants with sequential neuroangiogenesis promotion and osteoporosis pathological microenvironment improvement. Hot springs exhibits excellent facilitation on angiogenesis and bone regeneration due to abundant minerals, trace elements and modest thermal stimulation. Inspired by the hot spring effect, we propose a novel porous photothermal calcium magnesium phosphate bone cement (MCPC) compounded with manganese-substituted Fe3O4 (MnxFe3-xO4), which is perfused by temperature-responsive PLGA hydrogel loaded with vascular endothelial growth factor (VEGF) and nerve growth factor (NGF). At the initial stage of implantation, MnxFe3-xO4 scavenges excessive H2O2 under the heat stimulation triggered by near-infrared (NIR) light, and the factors are released from the hydrogel that stimulate the impaired neurovascular network reconstruction; at the later stage, the continuous hot spring effect maintains mild thermal stimulation and sustained release of bioactive ions (Ca2+, Mn2+, Mg2+ and PO43-), which inhibits osteoclast function and activity, and promotes osteogenic differentiation and mineralization. The osteoporotic bone defect model in ovariectomized (OVX) rats further verifies that a synergy effect of photothermal therapy and bioactive factors/ions significantly promotes neurovascular bone regeneration. It demonstrates that the hot spring mimetic effect possesses huge potential for the sequential treatment of osteoporosis bone defect.

Regulation of osteoimmune microenvironment via functional dynamic hydrogel for diabetic bone regeneration

Bone regeneration and repair face formidable challenges under diabetic conditions, primarily due to the disruption of macrophage polarization induced by diabetes and the inflammatory imbalance within the bone microenvironment. We have developed a novel dynamic hydrogel system (AG-CD@LINA), constructed through the coordination crosslinking of thiolated gelatin (SH-Gelatin) and gold ions (Au3+), followed by grafting with cyclodextrin to load the ligand linagliptin. This hydrogel effectively inhibits the formation of M1 macrophages and the expression of pro-inflammatory cytokines by gradually releasing linagliptin. Simultaneously, it promotes the formation of M2 macrophages and the expression of anti-inflammatory cytokines, thus improving the inflammatory microenvironment of diabetic bone defects. Consequently, it facilitates the migration of mesenchymal stem cells and angiogenic cells, augments osteogenic activity, and promotes vascularization, collectively accelerating the regeneration of diabetic bone tissue. Mechanistically, polarization occurs through the TLR3-NF-κB signaling pathway. In vivo experiments demonstrate that the in-situ injection of the hydrogel enhances the regeneration of bone tissue and the restoration of bone structure in diabetic bone defects, effectively modulating local inflammation and promoting vascular formation. This study suggests that functionalized dynamic hydrogels can improve the inflammatory microenvironment by regulating in situ macrophage polarization, thereby facilitating the reconstruction of bone microstructure. This approach represents a promising novel therapeutic strategy for diabetic bone defects.

Application and progress of hyperbaric oxygen therapy in cardiovascular diseases

Cardiovascular diseases remain the leading cause of death worldwide, underscoring the urgent need for additional therapeutic strategies to reduce their mortality rates. This review systematically outlines the historical development and recent advances of hyperbaric oxygen therapy in cardiovascular diseases, with a focus on its therapeutic mechanisms and clinical outcomes. Hyperbaric oxygen therapy enhances oxygen delivery to ischemic and reperfused tissues, promotes angiogenesis, and significantly suppresses oxidative stress, inflammatory cascades, and cardiomyocyte apoptosis, demonstrating multifaceted therapeutic potential in cardiovascular conditions. Specifically, hyperbaric oxygen therapy combined with reperfusion strategies has been shown to markedly improve left ventricular ejection fraction in acute myocardial infarction. In heart failure, it facilitates myocardial repair and enhances cardiac function. For arrhythmias, hyperbaric oxygen therapy effectively reduces the frequency and duration of premature ventricular contractions and paroxysmal tachycardia, while mitigating the risk of neurological complications following atrial fibrillation ablation. Furthermore, hyperbaric oxygen therapy preconditioning in cardiac surgery has demonstrated improvements in left ventricular stroke work, reductions in postoperative myocardial injury, and a decrease in related complications. Despite its promising applications, the widespread adoption of hyperbaric oxygen therapy remains hindered by the lack of standardized treatment protocols and high-quality evidence from rigorous clinical trials. In conclusion, this review underscores the potential value of hyperbaric oxygen therapy in the cardiovascular domain while highlighting the need for further optimization of therapeutic parameters and exploration of its synergistic effects with conventional therapies to provide clearer guidance for clinical implementation.

An injectable hydrogel loaded with miRNA nanocarriers promotes vessel-associated osteoclast (VAO)-mediated angiogenesis and bone regeneration in osteonecrosis of the rat femoral head

Osteonecrosis of the femoral head (ONFH) remains a significant clinical challenge. Despite various strategies aimed at promoting bone repair and halting disease progression, an effective cure remains elusive. Recent studies have identified a non-bone-resorbing osteoclast subtype, vessel-associated osteoclasts (VAOs), distinct from classical bone-associated osteoclasts (BAOs), offering new therapeutic opportunities for ONFH. Notably, we observed alterations in the populations and distributions of VAOs and BAOs in the femoral head of ONFH patients, suggesting that the imbalance between these two osteoclast subtypes contributes to ONFH pathology. Here, we developed an injectable alginate/hydroxyapatite hydrogel (AHH) loaded with graphene oxide-based miR-7b nanocarriers (GPC@miR) for ONFH treatment. The controlled release of GPC@miR from AHH/GPC@miR inhibited BAO formation by suppressing dendritic cell-specific transmembrane protein (DC-STAMP), thereby reducing bone resorption. Meanwhile, mono-/bi-nucleated VAOs were preserved and increased in number, promoting angiogenesis of type H vessels and osteogenesis via platelet-derived growth factor-BB (PDGF-BB) and vascular endothelial growth factor-A (VEGF-A) secretion. Intraosseous administration of AHH/GPC@miR rebalanced VAOs and BAOs, restored the femoral head microenvironment, and enhanced vascularization and bone regeneration in ONFH rat models. This study introduces a novel biomaterial-based strategy for ONFH repair by regulating osteoclast subtypes, providing insights into VAO-mediated angiogenesis and osteogenesis for bone regeneration.

Endogenous dual-responsive and self-adaptive silk fibroin-based scaffold with enhancement of immunomodulation for skull regeneration

Despite the current biomaterials (e.g. titanium mesh and polyether ether ketone) have been applied to clinical skull repair, the limitations on mechanical match, shape adaptability, bioactivity and osteointegration have greatly limited their clinical application. In this work, we constructed a water and inflammatory microenvironment dual-responsive self-adaptive silk fibroin-magnesium oxide-based scaffold with the matrix metalloproteinase-2-responsive gelatin-methacryloyl-interleukin-4 (IL-4) coating, which presented good mechanical compliance, quickly shape matching and intraoperative reprocessability. With the capability of responding to an acute inflammation microenvironment followed by a triggered on-demand release of the IL-4, the combination of immunoactive IL-4 and Mg2+ co-ordinately facilitated metabolic reprogramming by suppressing glycolysis, promoting mitochondrial oxidative phosphorylation and modulating adenosine 5'-monophosphate-activated protein kinase (AMPK) signalling pathways in macrophages, resulting in significantly facilitating M2 macrophage activation. During the stage of tissue remodelling, the sustained release of Mg2+ further promoted macrophage M2 polarization and the expression of anti-inflammatory cytokines, significantly reduced immune response and improved ectopic osteogenesis ability. Meanwhile, the cranial defect models of male rats demonstrated that this scaffold could significantly enhance biomineralized deposition and vascularisation, and achieve good bone regeneration of cranial defects. Overall, the bioactive scaffold provides a promising biomaterial and alternative repair strategy for critical-size skull defect repair.

Bioactive Zn ingredients endow Ti-Zn composites with exceptional mechanical and osteogenic properties as biomedical implants

Titanium-based (Ti-) alloys are promising materials as bioimplants with superior mechanical properties and excellent biocompatibility. However, their bioinertia and high elastic moduli are not comparable to natural bone tissue; thus, novel Ti alloys with good biomechanical adaptation and high bioactivity are desired. Zinc (Zn) is recognized for ideal biodegradability and its biological effects can be considered to endow pure Ti with rewarding bio functions. Herein, this study has employed a designed spark plasma sintering (SPS) procedure to effectively diffuse varying amounts of Zn into pure Ti as bioactive ingredients and generate novel TiZn composites as bone defect implants. The as-sintered TiZn samples feature a gradient core-shell structure, achieving a match of high strength and low elastic moduli to satisfy the load-bearing requirements while avoiding the stress-shielding effect. A moderate degradation of the Zn component allows TiZn materials to maintain stable mechanical support and exhibit satisfactory cytocompatibility. Ti20Zn, Ti30Zn, and Ti90Zn are confirmed to exert antibacterial and osteogenic abilities by in vitro experiments. Further analyses of in vivo implantation in the rat femur show they exhibit qualified biosafety and are superior to pure Ti in treating bone defects through bio-friendly Zn ions release. This study achieves a reasonable combination of the mechanical properties of pure Ti and the biological functions of pure Zn, providing a better choice for bone injury and fracture treatment.

Global trends in proximal femoral trabecular research: A bibliometric and visualized analysis

Introduction

Hip disease is a global public health issue, associated with high morbidity, mortality, and healthcare costs. Although research on proximal femoral trabeculae has been conducted for over a century, no bibliometric analysis has been carried out. The purpose of this study is to evaluate the existing research landscape, identify emerging trends, and offer insights for future studies.

Method

The scientific output related to the trabeculae within the human proximal femur from 2004 to 2023 was sourced from the Web of Science Core Collection. Moreover, both the annual publications and cumulative totals over this period were summarized in Excel. The VOS viewer was utilized to analyze co-authorship and co-citation relationship between authors, institutions, countries, references and journals. CiteSpace was used to cluster the keywords and research frontiers in this field.

Results

A total of 365 publications were extracted, with the USA emerging as the primary contributor to this field, accounting for 133 publications with 5807 total citations, averaging 43.7 citations per publication. The Journal of Bone and Mineral Research has been identified as the most co-cited journal with a total of 1742 citations. The journals can be categorized into 5 distinct clusters, including medical imaging, orthopedic clinical research, research on endocrine and metabolic related diseases, human evolution and anatomy related research, biomechanics and modeling. The keyword with the highest co-occurrence frequency is "bone mineral density". The keywords were stratified into six clusters, including DXA, bone remodeling, diagnosis, titanium alloy bionic cannulated screws, individual trabecula segmentation, and QCT. More recently, the focus has expanded to three-dimensional modeling, falls, microarchitecture, and avascular necrosis.

Conclusions

Evaluation of proximal femoral strength can be improved by combining structural parameters with bone mineral density by DXA or QCT. Three-dimensional analysis, microarchitecture, and bionic implants are emerging as significant areas of focus and trends for future research.

Co-stimulation with piezoelectric PVDF films and low intensity pulsed ultrasound enhances osteogenic differentiation

Bone tissue engineering has emerged as a promising approach to address the challenges of bone fracture repair and regeneration. The application of external stimuli (mechanical and electrical) can drive specific cellular responses and osteogenic differentiation, leading to the development of more effective treatments. Piezoelectric materials modulate cellular proliferation and osteogenic differentiation under both static (without mechanical stimulation) and dynamic (with mechanical stimulation) conditions, activating distinct gene expression pathways. In this work, we investigate the combinatorial effect of poly (vinylidene fluoride) (PVDF) poled and non-poled films, and low-intensity pulsed ultrasound (LIPUS) on early-stage osteogenic differentiation of mouse pre-osteoblasts. Static culture with PVDF poled films enhanced Runx2 and Col1α1 expression without impacting alkaline phosphatase (ALP) activity. Inhibition of ERK phosphorylation using U0126 in PVDF poled films resulted in a ~ 6-8-fold increase in ALP activity, suggesting the involvement of an alternative pathway in osteogenic differentiation. Dynamic culture with LIPUS generated an electric potential of approximately 500 mV across PVDF films and an electrical field of 0-10 mV mm-1. Co-stimulation led to a ~3-fold increase of ALP activity on stimulated PVDF compared to unstimulated films. This study underscores the potential of piezoelectric materials as non-invasive electrical stimulators to enhance the efficacy of ultrasound-based therapies for bone fracture repair.

An engineered M2 macrophage-derived exosomes-loaded electrospun biomimetic periosteum promotes cell recruitment, immunoregulation, and angiogenesis in bone regeneration

The periosteum, a fibrous tissue membrane covering bone surfaces, is critical to osteogenesis and angiogenesis in bone reconstruction. Artificial periostea have been widely developed for bone defect repair, but most of these are lacking of periosteal bioactivity. Herein, a biomimetic periosteum (termed PEC-Apt-NP-Exo) is prepared based on an electrospun membrane combined with engineered exosomes (Exos). The electrospun membrane is fabricated using poly(ε-caprolactone) (core)-periosteal decellularized extracellular matrix (shell) fibers via coaxial electrospinning, to mimic the fibrous structure, mechanical property, and tissue microenvironment of natural periosteum. The engineered Exos derived from M2 macrophages are functionalized by surface modification of bone marrow mesenchymal stem cell (BMSC)-specific aptamers to further enhance cell recruitment, immunoregulation, and angiogenesis in bone healing. The engineered Exos are covalently bonded to the electrospun membrane, to achieve rich loading and long-term effects of Exos. In vitro experiments demonstrate that the biomimetic periosteum promotes BMSC migration and osteogenic differentiation via Rap1/PI3K/AKT signaling pathway, and enhances vascular endothelial growth factor secretion from BMSCs to facilitate angiogenesis. In vivo studies reveal that the biomimetic periosteum promotes new bone formation in large bone defect repair by inducing M2 macrophage polarization, endogenous BMSC recruitment, osteogenic differentiation, and vascularization. This research provides valuable insights into the development of a multifunctional biomimetic periosteum for bone regeneration.

Fused exosomal targeted therapy in periprosthetic osteolysis through regulation of bone metabolic homeostasis

The onset of periprosthetic osteolysis is mediated by wear particles following artificial arthroplasty. This manifests as a disturbed bone metabolism microenvironment, characterized by insufficient osteogenesis and angiogenesis, and enhanced osteoclastic activity. To target and remodel the homeostatic environment of bone metabolism in the sterile region around the prosthesis, we successfully pioneered the proposal and construction of a fused exosome (f-exo) system with M2 macrophage-derived exosomes (M2-exo) and urine-derived stem cell exosomes (USC-exo). The results demonstrate that f-exo effectively combines the osteolysis region-targeting capabilities of M2-exo with the bone metabolic homeostasis modulation effects of two exosomes (M2-exo and USC-exo), thereby achieving a significantly enhanced bone metabolic homeostasis targeting effect in the periprosthetic osteolysis region. The proteomic analysis of M2-exo, USC-exo, and f-exo revealed the potential mechanism of f-exo in targeting-regulation of bone metabolic homeostasis. Our study employs an innovative approach utilizing the fused exosome system for exosome targeted delivery, which offers a novel intervention strategy for the clinical management of periprosthetic osteolysis. Furthermore, it provides a novel conceptual framework for the development of exosome-based drug-targeting delivery systems.

Hypophosphatasia: A case report

BACKGROUND

Hypophosphatasia (HPP) is a rare metabolic disorder caused by low tissue-nonspecific alkaline phosphatase (ALP) activity, presenting symptoms from bone demineralization to tooth loss. It affects multiple systems and is diagnosed based on clinical symptoms, radiological findings, and lab tests. This case report emphasizes considering HPP in patients with unexplained bone pain and low ALP levels, especially with underlying osteopenia or osteoporosis. It highlights the importance of genetic testing and counseling for early diagnosis and treatment, aiming to raise clinician awareness.

CASE SUMMARY

We present a case of a 65-year-old female patient who was referred to our endocrinology clinic for complaints of generalized bone pain and hypothyroidism. Initial evaluation revealed osteopenia, managed with calcium and vitamin D supplementation. Persistently low ALP levels and elevated vitamin B6 levels led to the diagnosis of HPP, confirmed by genetic testing identifying a pathogenic ALPL gene variant [c.119C>T (p.Ala40Val)]. Despite conservative treatment, her bone density declined, although remaining in the osteopenic range. The Fracture Risk Assessment score indicated a low risk of major osteoporotic and hip fractures, not warranting immediate treatment. Plans are underway to initiate enzyme replacement therapy with asfotase alfa.

CONCLUSION

Recognizing HPP is crucial, as early diagnosis and treatment can significantly improve patient outcomes and prevent complications.

Life-threatening vascular injury in an elderly patient with isolated pubic ramus fracture: A case report

BACKGROUND

Pubic ramus fractures are generally considered fragility fractures in the elderly population, commonly deriving from a low-impact fall. Treatment is ordinarily conservative and hemodynamic complications are exceedingly infrequent. Notwithstanding, patients with copious comorbidities should be carefully monitored for potential vascular injury.

CASE SUMMARY

This case report presents the management of a 75-year-old male patient with a history of diabetes mellitus and arterial hypertension who was admitted to the emergency room with a superior pubic ramus fracture. The patient experienced a significant drop in hematocrit and hemoglobin levels post-admission, necessitating urgent intervention. A computed tomography angiography revealed active bleeding, leading to the embolization of the medial femoral branch. The patient was stabilized hemodynamically and was discharged after 15 days, with recommendations for home-based follow-up care.

CONCLUSION

This report denotes the various challenges and strategies in managing simple fractures that are treated conservatively, but need prompt monitoring for occult vascular injuries that can be fatal.

TSH inhibits osteoclast differentiation through AMPK signaling pathway

PURPOSE

It is believed that osteoporosis (OP) is associated with hyperthyroidism as a result of the elevation in thyroxine levels. However, patients with subclinical hyperthyroidism, which is characterized by decreased levels of thyroid-stimulating hormone (TSH) alone, are at equal risk of osteoporosis. Research has shown that TSH receptor (TSHR) is expressed on osteoclasts, but whether TSH directly regulates osteoclasts and the underlying mechanisms remain unclear.

METHODS

In this study, we used osteoclast precursor cell conditional TSHR-knockout (TSHR CKO) mouse to study the effects of TSHR knockout on bone metabolism in mice and the changes in osteoclast differentiation in vitro. Transcriptomics was used to identify differentially expressed genes and signaling pathways.

RESULTS

In vitro, experiments confirmed that TSH inhibited osteoclast differentiation in mouse RAW264.7 monocyte/macrophage cell line and targeted the key signaling pathway AMPK by RNA-seq sequencing. We found TSHR CKO mice exhibited decreased femoral biomechanics and damaged bone microstructure. The serum levels of bone resorption marker were increased, accompanied by an increase in the number of osteoclasts.

CONCLUSION

TSH inhibits osteoclast differentiation by activating the AMPK signaling pathway, and exerts an osteoprotective effect. This study will provide guidance for the diagnosis and treatment of osteoporosis. TSH structural analogs or AMPK activators are expected to provide new ideas for the development of drugs to prevent and treat osteoporosis.

Advances and challenges in immunosuppressive antibody drug conjugates

Since the approval of Mylotarg™ in 2000 for acute myeloid leukemia, antibody-drug conjugates (ADCs) have significantly advanced precision medicine, particularly for oncology applications. ADCs combine an antibody, a linker, and a payload to result in a targeted therapeutic that minimizes toxicity resulting from systemic drug exposure. This review explores the innovative application of ADC technology towards immunosuppressive therapeutics, primarily focusing on antibody-mediated delivery of glucocorticoids (GCs). Despite their potent anti-inflammatory effects, the clinical use of GCs is limited by adverse systemic effects including osteoporosis, high blood sugar, adrenal insufficiency, weight gain, and glaucoma. Therefore, targeted delivery via ADCs presents a promising strategy to enhance therapeutic efficacy while reducing toxicity. Herein, we review the current status of immune-suppressing ADC technology, starting with early investigations of CD163-targeted dexamethasone and moving to the design of ADCs employing next-generation ultra-potent GCs. Additionally, we will discuss the current status of anti-inflammatory ADCs that employ non-glucocorticoid immune-suppressive medications. Throughout, we will highlight preclinical and clinical data that serves to derisk and drive investment in this new therapeutic class. In parallel, we will focus on ADC design principles that illustrate the importance of careful selection of payload, linker, and conjugation technology in this emerging field.

The paradigm shifts of periodontal regeneration strategy: From reparative manipulation to developmental engineering

Ideal periodontal regeneration requires the integration of alveolar bone, periodontal ligament, and cementum, along with Sharpey's fibers for occlusal force resistance. However, physiological regeneration remains rare due to its intricate structure, making clinical regeneration a challenge. Periodontal ligament stem cells (PDLSCs), first isolated in 2004, hold the key to multi-directional differentiation into cementoblasts, fibroblasts, and osteoblasts. While traditional therapies like guided tissue regeneration (GTR) aim to activate PDLSCs, clinical outcomes are inconsistent, suggesting the need for additional strategies to enhance PDLSCs' functions. Advancements in molecular biotechnology have introduced the use of recombinant growth factors for tissue regeneration. However, maintaining their efficacy requires high doses, posing cost and safety issues. Multi-layered scaffolds combined with cell sheet technology offer new insights, but face production, ethical, and survival challenges. Immune regulation plays a crucial role in PDLSC-mediated regeneration. The concept of "coagulo-immunomodulation" has emerged, emphasizing the coupling of blood coagulation and immune responses for periodontal regeneration. Despite its potential, the clinical translation of immune-based strategies remains elusive. The "developmental engineering" approach, which mimics developmental events using embryonic-stage cells and microenvironments, shows promise. Our research group has made initial strides, indicating its potential as a viable solution for periodontal complex regeneration. However, further clinical trials and considerations are needed for successful clinical application. This review aims to summarize the strategic transitions in the development of periodontal regenerative materials and to propose prospective avenues for future development.

Advances in the mechanism and therapies of achondroplasia

Achondroplasia (ACH), is the prevailing type of genetic dwarfism in humans, caused by mutations in fibroblast growth factor receptor 3 (FGFR3) that are inherited in an autosomal dominant manner. FGFR3 is mainly expressed in condensed mesenchyme, chondrocytes, and mature osteoblasts and osteoclasts, in which it regulates the formation, development, growth, and remodeling of the skeletal system. Mutations in FGFR3 causing ACH result in enhanced FGFR3 signaling through combined mechanisms including enhancing FGF dimerization and tyrosine kinase activity and stabilizing FGF receptors. In ACH, suppression of the proliferation and maturation of chondrocytes in the growth plate leads to a notable reduction in growth plate size, trabecular bone volume, and bone elongation through a profound enhancement of FGFR3 signaling. This review aims to comprehensively outline the cellular and molecular mechanisms contributing to the pathological process of ACH and its potential therapeutic interventions.

Periprosthetic osteolysis: Mechanisms and potential treatment strategies

Periprosthetic osteolysis is a common bone-related disorder that often occurs after total hip arthroplasty. The implants can cause damage to bone and bone-related cells due to mechanical stress and micromotions, resulting in the generation of a large number of wear particles. These wear particles trigger inflammation and oxidative stress in the surrounding tissues, disrupting the delicate balance maintained by osteoblasts and osteoclasts, ultimately leading to bone loss around the implant. Clinical investigations have demonstrated that Epimedium prenylflavonoids, miR-19a-3p, stem cell-derived exosomes, and certain non-PPO category pharmaceuticals have regulatory effects on bone homeostasis through distinct molecular pathways. Notably, this phenomenon reflects inherent biological rationality rather than stochastic occurrence. Extensive research has revealed that multiple natural compounds, non-coding RNAs, exosomes, and non-PPO therapeutics not only exert modulatory influences on critical pathophysiological processes including inflammatory cascades, oxidative stress responses, and tissue regeneration mechanisms, but also effectively regulate bone-related cellular functions to inhibit PPO progression. Therefore, this review comprehensively and systematically summarizes the main pathogenic mechanisms of periprosthetic osteolysis. Furthermore, it delves deeper into the research progress on the applications of currently reported natural products, ncRNAs, exosomes, and non-PPO medications in the treatment of periprosthetic osteolysis. Based on this, we hope that this paper can provide new perspectives and references for the future development of drugs targeting periprosthetic osteolysis.

Stiffness regulates extracellular matrix synthesis in fibroblasts by DDR1-TGF-β/STAT3 mechanotransduction axis

For a long time, research on atherosclerosis (AS) has mainly focused on endothelial cells (ECs) and smooth muscle cells (SMCs) in blood vessels. Fibroblasts, however, being the major component in adventitia, little is known about their role. Fibroblasts are highly plastic cells, capable of undergoing phenotypic changes in response to various extracellular signals. Once activated, fibroblasts can promote fibrosis by altering the secretion of extracellular matrix (ECM). In this study, the effect of ECM stiffness on fibroblasts was investigated. Polyacrylamide (PA) gels with varying elastic moduli (1 kPa, 20 kPa and 100 kPa) were used as models for matrix stiffness. Human fibroblasts were cultured on these substrates, and their phenotypic and functional changes were examined. The data revealed that a collagen-binding receptor, Discoidin Domain Receptor 1 (DDR1), plays a central role in sensing mechanical stimuli from ECM. Matrix stiffness-induced phosphorylation of DDR1 suppresses the synthesis of ECM proteins in fibroblasts. The expression of ECM proteins on the 1 kPa substrate was significantly higher than that on the 20 kPa and 100 kPa substrates, while the phosphorylation level of DDR1 was notably reduced. After knocking out DDR1, the difference in ECM proteins expression among the three substrates with different stiffness levels disappeared. The signal transduction from DDR1 to ECM synthesis is mediated by the TGF-β/STAT3 signaling axis. Our study reveals how matrix stiffness regulates the synthesis of ECM in fibroblasts and paves the way for understanding the regulation of fibrotic process in the pathogenesis of AS.

The role of RGS12 in tissue repair and human diseases

Regulator of G protein signaling 12 (RGS12) belongs to the superfamily of RGS proteins defined by a conserved RGS domain that canonically binds and deactivates heterotrimeric G-proteins. As the largest family member, RGS12 is widely expressed in many cells and tissues. In the past few decades, it has been found that RGS12 affects the activity of various cells in the human body, participates in many physiological and pathological processes, and plays an important role in the pathogenesis of many diseases. Here, we set out to comprehensively review the role of RGS12 in human diseases and its mechanisms, highlighting the possibility of RGS12 as a therapeutic target for the treatment of human diseases.

Cyclodextrin-based self-assembling hydrogel for Photothermal-controlled nitric oxide release in stage-specific treatment of MRSA-induced arthritis

MRSA-induced arthritis is a prevalent and highly debilitating orthopedic condition. The inflammatory response induced by bacterial infection hinders tissue repair and exacerbates bone loss. Traditional antibiotic therapies are limited by low bioavailability, substantial side effects, and narrow efficacy, rendering them inadequate for comprehensive treatment of arthritis. Nitric oxide (NO) has demonstrated considerable potential in overcoming bacterial resistance, modulating immune responses, and facilitating tissue repair. Therefore, a stage-specific NO release strategy, tailored to the distinct phases of bacterial arthritis, is essential for effective treatment. In this study, mesoporous polydopamine nanoparticles were utilized as NO donors (mPDA/NONOate) and encapsulated within a supramolecular hydrogel formed via the host-guest interaction between α-cyclodextrin (α-CD) and Pluronic F127. The injectable nature of the resulting NO/PDA-Gel hydrogel ensured uniform distribution within irregular bone joint infection sites, minimizing NO donor loss and enhancing local bioavailability. Notably, upon near-infrared (NIR) irradiation, the hydrogel induces a rapid increase in local temperature, facilitating rapid NO release. At the same time, the synergistic photothermal effect effectively kills bacteria and rapidly controls the infection. Without light irradiation, NO is sustainably and stably released from the NO/PDA-Gel, modulating the bone immune microenvironment, alleviating inflammation, promoting chondrocyte proliferation and differentiation, and accelerating bone tissue repair, thus significantly shortening the healing time of MRSA-induced arthritis. In conclusion, the injectable self-assembled NO/PDA-Gel offers a precise, stage-matched therapeutic approach for MRSA-induced arthritis and holds promise for the treatment of deep-seated infections caused by other multidrug-resistant pathogens.

Influences and strategies for bone regeneration based on microenvironment pH adjustment

Bone possesses remarkable endogenous regenerative capacity. Bone regeneration is typically divided into three stages: inflammation, bone formation, and bone remodeling, during which pH is a critical variable. The influence of pH on the bone regeneration process depends on three main factors: (1) the activity and differentiation of cells involved in bone regeneration are affected by pH; (2) protein activity is regulated by pH; and (3) extracellular calcium phosphate precipitates in a pH-dependent manner. The aim of this study is to review the mechanisms by which microenvironment pH affects bone regeneration and to explore specific sites and signaling pathways involved in pH regulation during the bone regeneration process. Therapeutic approaches aimed at enhancing bone regeneration via modulation of microenvironment pH are discussed, including pH adjustment via biological implant materials, pH-responsive material setting, and pH stabilization through anti-inflammatory therapy. Investigating the impact of microenvironment pH on bone regeneration is of considerable clinical importance, as it provides valuable insights for improving the success rates of bone implants and promoting bone healing. This review offers insights into regulatory mechanisms, establishes theoretical foundations, and presents new perspectives for current research on bone defect repair.

The effect of oral colchicine and vitamin K1 on bone metabolism in patients with diabetes mellitus: A post-hoc analysis of a 2 × 2 factorial randomized controlled trial with 18F-sodium fluoride positron emission tomography

PURPOSE

Diabetes mellitus (DM) confers an increased risk of fracture. Fracture risk stratification techniques are imperfect, and preventative therapies are sparse. We aimed to describe features associated with a dysfunctional bone metabolism determined by 18F-Sodium Fluoride Positron Emission Tomography (18F-NaF PET) in patients with DM and test the effects of vitamin K1 and colchicine therapy on vertebral 18F-NaF activity.

METHODS

This is a post-hoc analysis of a 2 × 2 factorial randomized double-blind placebo-controlled trial. Participants aged 50-80 with DM underwent 18F-NaF PET/CT imaging at baseline, 3 months of therapy with vitamin K1 (10mg/daily) or placebo, and colchicine (0.5 mg/day) or placebo and repeat 18F-NaF PET/CT. The 18F-NaF vertebral mean standardized uptake value (SUVmean) and the CT estimated bone mineral density (BMD) (in Hounsfield units) was evaluated from thoracic vertebra.

RESULTS

In total, 149 individuals (66.4 % male, mean age 65.5 ± 6.8 years) were included. Male sex (β -1.421, 95 % CI [-1.826, -1.016], p < 0.001), duration of DM in years (-0.021 [-0.039, -0.002], p = 0.030) and CT estimated vertebral BMD (0.011 [0.006, 0.015], p < 0.001) were independently associated with the SUVmean. The change in the SUVmean was similar between vitamin K1 or placebo groups (-0.07 ± 0.64 v 0.07 ± 0.69, p = 0.20). Participants receiving colchicine therapy had a greater reduction in the SUVmean, compared with placebo (-0.12 ± 0.72 v 0.11 ± 0.60, p = 0.039).

CONCLUSION

18F-NaF PET may be a useful measure of vertebral bone metabolism in people with DM. Three months of oral colchicine reduced the 18F-NaF vertebral SUVmean, whereas Vitamin K1 had no effect. The findings should be considered hypothesis generating.

TRIAL REGISTRATION

www.anzctr.org.au (ACTRN12616000024448).

Exercise alleviates osteoporosis by regulating the secretion of the Senescent Associated Secretory Phenotype

As the elderly population grows, the number of patients with metabolic bone diseases such as osteoporosis has increased sharply, posing a significant threat to public health and social economics. Although pharmacological therapies for osteoporosis demonstrate therapeutic benefits, their prolonged use is associated with varying degrees of adverse effects. As a non-pharmacological intervention, exercise is widely recognized for its cost-effectiveness, safety, and lack of toxic side effects, making it a recommended treatment for osteoporosis prevention and management. Previous studies have demonstrated that exercise can improve metabolic bone diseases by modulating the Senescent Associated Secretory Phenotype (SASP). However, the mechanisms through which exercise influences SASP remain unclear. Therefore, this review aims to summarize the effects of exercise on SASP and elucidate the specific mechanisms by which exercise regulates SASP to alleviate osteoporosis, providing a theoretical basis for osteoporosis through exercise and developing targeted therapies.

Global morphogenesis regulating tissue architecture and organogenesis

This perspective article proposes that the induction of bone by recombinant human bone morphogenetic proteins (hBMPs), and by the recombinant human transforming growth factor-β3 (hTGF-β3), the latter only in primates, recapitulates embryonic development, whereby large ossicles de novo form in heterotopic intramuscular sites, where several responding cells are available with marked vascular invasion. The induction of bone initiates with the induction of cartilage' anlages recapitulating development. Selected recombinant hBMPs, hBMP-2 and hOP-1 (hBMP-7) on the other hand, fail to induce significant osteoinduction in orthotopic intraskeletal sites in clinical contexts. This review proposes that the failure of significant clinical bone formation in orthotopic sites is because implantation of hBMP-2 and hOP-1, as well as hTGF-β3 in human mandibular sites, does not proceed via recapitulation of embryonic development, ultimately failing the clinical translation of the "bone induction principle". Biologically, a prerogative of the osteogenic proteins of the TGF-β super family, is the heterotopic induction of bone that initiates via recapitulation of embryonic bone development. Delivery of recombinant hBMP-2 and/or hOP-1 into human bony defects fails because the induction of bone is possible only via embryonic development, which does not occur in orthotopic sites, with limited responding cells and vascular supply. The initiation and assembly of the bone/bone-marrow organ follow a multistep molecular and cellular cascades that ultimately morphogenize the assembly of skeletogenesis masterminding ambulation, body erection, masticatory functions, copulation and the preservation of vital organs and tissues such as the marrow and the cerebral hemispheres. Embryologically, bone forms either via mesenchymal osteogenesis or via endochondral osteogenesis. The former route prevalently sculpts the craniomandibulofacial bones by inducing aggregation of targeted mesenchymal cells to condensate in the primordia of the craniofacial skeleton. A critical step is the condensation of mesenchymal cells that forms around vessels, as the vessels guide the formation of bone. Endochondral osteogenesis initiates by firstly constructing cartilage' anlages that developing bone uses as struts to growth and differentiate. The cartilage anlage is an extraordinary conduit that sets into motion molecular and cellular cell-to-cell, cell-to-receptors cross-talking to initiate angiogenesis and capillary invasion within the hypertrophic cartilage, chondrolysis that initiate osteoblastic cellular differentiation and the deposition of bone, osteoid synthesis, bone marrow development and the induction of a complete mineralized bone-bone marrow organ. The assembled constructs are storage of critical ions, several structural proteins such as osteonectins and fibronectins, biological markers of osteoblast' secretion and activity, such as osteocalcin, together with an array of extraordinary morphogen initiators that de novo set into motion the molecular and cellular cascades inducing bone in heterotopic sites recapitulating embryonic development. In evolutionary molecular biology contexts however, the pleiotropic activities of both proteins' family and the induction of bone formation in heterotopic sites are developmental, and thus not suitable to induce bone when recombinant morphogens are singly implanted in orthotopic skeletal defects, the latter lacking the developmental biological platform.

Accurate measurement of a bone surrogate flexural rigidity in three- and four-point bending

The mechanical assessment of long bones through bending is an established preclinical approach to evaluate the effectiveness of treatments for osteoporosis and fractures. Three- and four-point bending (3PB and 4PB) tests are the most common methods for mechanical characterization of long bones with Euler-Bernoulli (EB) theory to calculate of bone flexural rigidity (EI). Previous studies demonstrated that EB theory underestimates the EI of long bones due to its reliance on assumptions that are not entirely applicable to long bones. Therefore, the current study aimed to evaluate the factors that affect the percent error (PE) and bias stemming from the omission of contact and shear deflections in the EI estimation using mechanical testing and finite element analysis (FEA). The true EI of a porcine bone surrogate was used to quantify the percent error and bias of EI estimations from three deflection measurement methods and FEA, in 3PB and 4PB. The analysis confirmed that bending was the main component of total deflection, but only contributed to approximately 50 % and 65 % of the total deflection in 3PB and 4PB, respectively. The combined shear and indentation deflections accounted for the remainder of the total deflection. The FEA aligned with 3PB and 4PB tests with less than 10 % deviation. Underestimation of EI was largest with deflection measurements taken from the machine crosshead (PE 74 % in 3PB and 71 % in 4PB). However, these underestimations improved notably when indentation and shear deflections were considered (PE 42 % in 3PB and 39 % in 4PB). The deflection measurements from extensometer and digital image correlation (DIC) underestimated the EI by 66 % and 71 % in 3PB, and 57 % and 59 % in 4PB. When corrected for shear and indentation deflections, the 3PB PE reduced to 16 % and 14 %, respectively. In 4PB, PE reduced to, 10 % and 7 %, respectively, demonstrating the advantage of the 4PB test configuration over 3PB. The bias resulting from shear deflection was not consistent across deflection measurement methods; and therefore, cannot be generalized with a constant bias correction. The current study highlighted that a slight error in deflection measurement can lead to a significant inaccuracy in EI measurements. This sensitivity comes from the hyperbolic relationship between EI and deflection which not only depends on the ratio of support span to diameter of the specimen but also the test configuration and the ratio of the elastic to shear modulus of specimen. In other words, the PE from neglecting shear effects increases as the specimen EI increases. Accuracy with less than 10 % PE in EI estimations can be achieved by: 1. taking deflection measurements with extensometers, DIC, or FEA; 2. testing in 4PB instead of 3PB; and, 3. correcting for indentation and shear deflections.

From hard tissues to beyond: Progress and challenges of strontium-containing biomaterials in regenerative medicine applications

Tissue engineering and regenerative medicine have emerged as crucial disciplines focused on the development of new tissues and organs to overcome the limitations of traditional treatments for tissue damage caused by accidents, diseases, or aging. Strontium ion (Sr2+) has garnered significant attention for its multifaceted role in promoting regeneration medicine and therapy, especially in bone tissue regeneration. Recently, numerous studies further confirm that Sr2+ also plays a critical in soft tissue regeneration. This review firstly summarizes the influence of Sr2+ on critical biological processes such as osteogenesis, angiogenesis, immune modulation, matrix synthesis, mineralization, and antioxidative defence mechanisms. Then details the classification, properties, advantages, and limitations of Sr-containing biomaterials (SrBMs). Additionally, this review extends to the current applications of SrBMs in regenerative medicine for diverse tissues, including bone, cartilage, skeletal muscle, dental pulp, cardiac tissue, skin, hair follicles, etc. Moreover, the review addresses the challenges associated with current SrBMs and provides insights for their future designing and applications in regenerative medicine.

CRISPR/CasRx-mediated RNA knockdown targeting β-catenin and Ihh signaling alleviates osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint disease. Currently, OA is incurable. Abnormal activation of canonical Wnt/β-catenin or Indian hedgehog (Ihh) signaling could lead to OA development and progression. This study aimed to determine if targeting β-catenin and Ihh signaling could yield an effective therapeutic intervention for OA disease. CRISPR/CasRx is a new RNA interference tool that can precisely and efficiently cleave single-strand RNAs. In this study, we screened CRISPR-derived RNA (crRNA) targeting Ctnnb1 and Smo in vitro and selected two optimal crRNAs for each gene. CasRx-mediated Ctnnb1 and Smo knockdown showed high efficiency and specificity with no obvious off-target effects in vitro. We then performed intra-articular injection of selected crRNAs driven by the adeno-associated virus into an OA mouse model. Micro-CT, histological, and histomorphometric analyses were conducted to evaluate the efficacy of CasRx approach on OA treatment. We found that the knockdown of Ctnnb1 and Smo decelerated pathological damage in the keen joint of the experimental OA mouse model. Our findings suggest that CasRx-mediated Ctnnb1 and Smo knockdown could be a potential strategy for OA treatment.

Small and porous ossicles, with flat stapes footplate and incudal fractures in the oim mouse model of osteogenesis imperfecta

Hearing loss affects approximately 70% of individuals with osteogenesis imperfecta (OI), a genetic connective tissue disorder characterized by bone fragility and deformities. No effective treatments exist for OI hearing loss, and its etiology is unknown limiting the development of new targeted therapies. This work investigates the impact of OI type I collagen mutations on the ossicle bone properties in the homozygous oim mouse model of severe OI, which is known to exhibit hearing loss. The morphology and porosity of the ossicles of 14-week-old oim and wild-type mice were analyzed using high-resolution synchrotron radiation microtomography. Additionally, the collagen fibers structure, bone tissue composition and mechanical properties were evaluated through second harmonic generation microscopy, Raman spectroscopy, and nanoindentation. The results demonstrated that oim ossicles are small, highly porous with an elevated lacunar number density, a flat stapes footplate and a small malleal processus brevis. One-in-two oim ossicles had incudomalleal joint abnormalities, exhibiting either a localized fracture in the incus head or a joint space widening. No differences were observed in collagen fibers structure, bone tissue composition and mechanical properties. These findings suggest that bone fractures observed in the oim incudes may contribute to their reported hearing loss. However, the underlying mechanism for these fractures' development remains to be investigated, as they do not appear to result from changes in bone tissue properties (collagen fibers organization, tissue composition or mechanical properties). Instead, they may be associated with joint space widening, and possibly altered ossicle chain kinematics.

Characterization of strains induced by in vivo locomotion and axial tibiotarsal loading in a chukar partridge model

Rodent models have offered valuable insights into the mechanobiological mechanisms that regulate bone adaptation responses to dynamic mechanical stimuli. However, using avian models may provide new insights into the mechanisms of bone adaptation to dynamic loads, as bird bones have distinct features that differ from mammalian bones. This paper illuminates these aspects by evaluating the mechanical environment in a novel avian, chukar partridge tibiotarsus (TBT), during fast locomotion and in cortical and cancellous tissue under in vivo dynamic compressive loading within the TBT. We measured in vivo mechanical strains at the TBT midshaft on the anterior, medial, and posterior surfaces during locomotion at various treadmill speeds. The mean in vivo strains measured on the anterior, medial, and posterior surfaces of the TBT midshaft were 154 με, -397 με, and -438 με, respectively, at a treadmill speed of 2 m/s. The mean experimentally measured strains on the anterior, medial, and posterior surfaces of the TBT were 114.7 με, -952.6 με, and -593.7 με under an in vivo dynamic compressive load of 130 N. The study, which employs a micro-computed tomography (microCT) based finite element model in combination with diaphyseal strain gauge measures, found that cancellous strains were greater than those in the midshaft cortical bone. Sensitivity analyses revealed that the material property of cortical bone was the most significant model parameter. In the midshaft cortical volume of interest (VOI), daily dynamic loading increased the maximum moment of inertia and reduced the bone area in the loaded limb compared to the contralateral control limb after three weeks of loading. Despite the strong correlations between the computationally modeled strains and experimentally measured strains at the medial and posterior gauge sites, no correlations existed between the computationally modeled strains and strain gradients, and histologically measured bone formation thickness at the mid-diaphyseal cross-section of the TBT.

Scanning acoustic microscopy for biomechanical characterization of reindeer antler using singular spectral analysis

Scanning Acoustic Microscopy (SAM) has become a vital tool in materials science and biology, allowing for non-destructive and non-invasive analysis of biological specimens and bio-inspired materials. Its deep-penetrating imaging capabilities enable a broad range of applications. This study combines SAM with Singular Spectral Analysis (SSA) to enhance signal processing and extract key data, particularly acoustic impedance. Reindeer antlers, known for their rapid growth and unique mechanical properties, were chosen as a focus for this method. SAM was used to quantify the specific acoustic impedance, longitudinal stiffness, bulk modulus, and Young's modulus of the material at three orientations (0°, 45°, and 90°). This analysis provides a comprehensive understanding of the directional dependence of its structural behavior, highlighting its orthotropic nature. By analyzing cross-sections along three axes, this study reveals the orthotropic biomechanical properties of reindeer antlers, offering a systematic approach to characterizing biological materials. Their unique strength, resilience, and rapid growth highlight their potential as a sustainable and innovative biomaterial for bioengineering and advanced composites.

Biomarkers of aging: from molecules and surrogates to physiology and function

Many countries face an unprecedented challenge in aging demographics. This has led to an exponential growth in research on aging, which, coupled to a massive financial influx of funding in the private and public sectors, has resulted in seminal insights into the underpinnings of this biological process. However, critical validation in humans has been hampered by the limited translatability of results obtained in model organisms, additionally confined by the need for extremely time-consuming clinical studies in the ostensible absence of robust biomarkers that would allow monitoring in shorter time frames. In the future, molecular parameters might hold great promise in this regard. In contrast, biomarkers centered on function, resilience, and frailty are available at the present time, with proven predictive value for morbidity and mortality. In this review, the current knowledge of molecular and physiological aspects of human aging, potential antiaging strategies, and the basis, evidence, and potential application of physiological biomarkers in human aging are discussed.