Bone Destruction Research Articles

N-(4-methoxyphenyl) quinoline-8-sulfonamide reduces the inflammatory response of fibroblast-like synoviocytes by targeting receptor (calcitonin) activity modifying protein 1 in rheumatoid arthritis

BackgroundRheumatoid arthritis (RA) is characterized by chronic inflammation of the synovium of joints. Fibroblast-like synoviocytes (FLS) play an important role in RA pathogenesis. We aimed to investigate the effect of N-(4-methoxyphenyl) quinoline-8-sulfonamide (QS-3g) on the inflammatory response of FLS and explore the potential underlying mechanisms. MethodsWe screened and found that QS-3g exhibits the best anti-inflammatory response against FLS using the CCK8 assay. To investigate the therapeutic effects of QS-3g on K/BxN STA mice, we used H&E staining, immunofluorescence, immunohistochemistry, micro-CT, and other techniques. Additional investigations, including RNA-seq, molecular docking, and CETSA, revealed that QS-3g binds to RAMP1. ResultsAmong a series of 8-quinoline sulfonyl amide derivatives, QS-3g reduced the inflammatory response in TNF-α stimulated FLS, such as the release of interleukin (IL)-1β and IL-6. H&E staining and micro-CT showed that QS-3g inhibited synovial hypertrophy, inflammatory cell infiltration, and bone destruction. RNA-seq and CETSA analyses revealed the targeted inhibition of RAMP1 by QS-3g. Inhibition of RAMP1 expression could reduce IL-6 and IL-1β levels. Compared with RAMP1-si, combined administration of QS-3g and RAMP1-si reduced the TNF-α-induced inflammation in TNF-α stimulated FLS without statistically significant differences. Finally, the results of in vitro experiments showed that QS-3g could restore the balance of Gαi/Gαs by inhibiting Gαi and activating Gαs and up-regulate the expression of cAMP protein, thus inhibiting the RAMP1-mediated inflammatory response in FLS. ConclusionQS-3g could inhibit RAMP1 activity and mediate the Gαs/Gαi–cAMP pathway to reduce FLS inflammatory response. Therefore, QS-3g may serve as a novel anti-inflammatory compound for treating RA.

Matrix-bound nanovesicles alleviate particulate-induced periprosthetic osteolysis.

Aseptic loosening of orthopedic implants is an inflammatory disease characterized by immune cell activation, chronic inflammation, and destruction of periprosthetic bone, and is one of the leading reasons for prosthetic failure, affecting 12% of total joint arthroplasty patients. Matrix-bound nanovesicles (MBVs) are a subclass of extracellular vesicle recently shown to mitigate inflammation in preclinical models of rheumatoid arthritis and influenza-mediated "cytokine storm." The molecular mechanism of these anti-inflammatory properties is only partially understood. The objective of the present study was to investigate the effects of MBV on RANKL-induced osteoclast formation in vitro and particulate-induced osteolysis in vivo. Results showed that MBV attenuated osteoclast differentiation and activity by suppressing the NF-κB signaling pathway and downstream NFATc1, DC-STAMP, c-Src, and cathepsin K expression. In vivo, local administration of MBV attenuated ultrahigh molecular weight polyethylene particle-induced osteolysis, bone reconstruction, and periosteal inflammation. The results suggest that MBV may be a therapeutic option for preventing periprosthetic loosening.

Bone Destruction-Chemotactic Osteoprogenitor Cells Deliver Liposome Nanomedicines for the Treatment of Osteosarcoma and Osteoporosis.

Therapeutic efficacy of skeletal diseases is usually limited by unfavorable drug delivery due to incapable bone targeting and low bone affinity of conventional drug carriers, as well as relatively reduced vascularization and dense structure of bone tissues. Due to CXC chemokine receptor 4 (CXCR4)/CXC chemokine ligand 12 (CXCL12) signal axis-guided recruitment, osteoprogenitor cells (OPCs) can actively migrate to bone disease nidus. Here, drugs-loaded nanoliposomes are prepared and decorated onto OPCs by biotin-streptavidin linkage for precise bone disease targeting and effective drug delivery. In mouse models of tibia defect and orthotopic osteosarcoma, superior targeting property of OPCs-based drug delivery systems toward diseased bone niduses is verified. By encapsulating antitumor and antiosteoporosis drugs into nanoliposomes, OPCs-based drug delivery systems effectively inhibit disease development and restore bone destruction in mouse models of orthotopic osteosarcoma and ovariectomized osteoporosis. This study reveals a cell-based drug delivery system for precise bone disease targeting and highly effective drug delivery, which will find great potential as a universal drug delivery platform for targeting treatment of various bone diseases.

Predictive value of tooth and sinuses radiological characteristics in managing odontogenic sinusitis of endodontic origin.

One of the most common causes of bacterial odontogenic sinusitis (ODS) is endodontic disease with periapical lesions (PAL). Referrals between otolaryngologists and dental specialists are indispensable for proper diagnosis and treatment. If the disease does not resolve after medical and root-canal treatment (RCT), tooth extraction, endoscopic sinus surgery (ESS) or both are the ways of management.The aim was to clarify the predictive value of disease's radiological characteristics for the further surgical intervention. 68 symptomatic patients evaluated by an otolaryngologist and dental specialist were included to this prospective observational cohort study. Patients who failed medical treatment of sinusitis (intranasal steroids, saline rinses and antibiotics) and RCT were treated either with ESS, tooth extraction or both at the same time. 87% of patients required surgical intervention. 12% improved after tooth extraction alone, 47% after ESS and 31% required both procedures. The degree of maxillary sinus' (MS) opacification was not correlated with the need of invasive procedures implementation, as opposed to ostiomeatal complex' patency (p<0.001). Cortical bone destruction towards the MS and multiple tooth roots involvement suggested ODS resolution only after combined surgical approach (p=0.041). Radiological characteristics of causative tooth and patency of ostiomeatal unit correlate with the evolution of ODS and need for either ESS and/or tooth extraction. Patients with multiple roots affected, shorter distance to the MS floor and PAL's with visible bone destruction may require tooth extraction and ESS to resolve ODS completely. Radiological data may help in earlier diagnosis and treatment of ODS with PALs for both otolaryngologists and dental specialists.

Butyrate: a bridge between intestinal flora and rheumatoid arthritis.

In patients with rheumatoid arthritis (RA), intestinal flora imbalance and butyrate metabolism disorders precede clinical arthritis and are associated with the pathogenesis of RA. This imbalance can alter the immunology and intestinal permeability of the intestinal mucosa, leading to damage to the intestinal barrier. In this context, bacteria and their metabolites can enter the bloodstream and reach the distant target tissues of the host, resulting in local inflammation and aggravating arthritis. Additionally, arthritis is also exacerbated by bone destruction and immune tolerance due to disturbed differentiation of osteoclasts and adaptive immune cells. Of note, butyrate is a metabolite of intestinal flora, which not only locally inhibits intestinal immunity and targets zonulin and tight junction proteins to alleviate intestinal barrier-mediated arthritis but also inhibits osteoclasts and autoantibodies and balances the immune responses of T and B lymphocytes throughout the body to repress bone erosion and inflammation. Therefore, butyrate is a key intermediate linking intestinal flora to the host. As a result, restoring the butyrate-producing capacity of intestinal flora and using exogenous butyrate are potential therapeutic strategies for RA in the future.

Investigation of the Effects of Ozon and Propolis on the Healing of Bone Defects: An Experimental Study

Background/aim: This study explores the effects of ozone and propolis on the healing of critically sized bone defects at both the histologic and molecular levels, and the locations and concentrations of osteopontin and osteonectin during healing; both proteins play roles during bone healing. Materials and methods: This study used 56 adult male Sprague-Dawley rats of an average weight of 350 g, divided into four groups of 14: a control group, a topical ozone group (O), a topical ozone + systemic propolis (O + PO) group, and a systemic propolis group (PO). Seven rats from each group were sacrificed at the end of week 4 and the other seven at the end of week 6. Tissues were subjected to histologic and immunohistochemical examinations in a fixative solution. The results were analyzed using the statistical software package SPSS 23 (Statistical Package for the Social Sciences—IBM). Results were considered significant at the 95% confidence level (P<0.05). Results: Graft sections were immunostained for osteonectin. Staining was low in the control group but moderate in the other three groups; the differences were significant. The three experimental groups did not differ significantly. Graft sections were also immunostained for osteonectin. At 4 weeks, staining was low in the control group but moderate in the other 3 groups. At 6 weeks, stronger staining was apparent in the 3 experimental groups. At both 4 and 6 weeks, the differences between the control and experimental groups were significantly different, but the differences among the experimental groups were not. Conclusion: The authors' results are compatible with the literature. Ozone and propolis, given separately or together, improved bone healing, increased bone formation, and reduced bone destruction. However, further research is required.

Analysis of errors in endodontic treatment according to cone-beam computed tomography

AIM. The aim of the study was to study the frequency of errors in endodontic treatment according to cone beam computed tomography.MATERIALS AND METHODS. 71 cone beam computed tomography (CBCT) scans of patients treated by random sampling who sought treatment and consultation in the period 2022–2023 were studied. 256 teeth previously subjected to endodontic treatment with the presence or absence of radiological signs of chronic apical periodontitis were examined. The assessment of the quality of root canal obturation and the features of the anatomical structure of teeth was carried out. The data of the «Ray RAYSCAN alpha 3D» cone beam computed tomograph were studied using the OnDemand3DDental program. The results were considered statistically significant at p< 0.05.RESULTS. In 57.42% of cases, there were no signs of periapical pathology, and in 42.58%, foci of bone destruction in the periapical region were observed. Homogeneously, 58.59% of root canals were sealed to the apex. In 16.79% of cases, the removal of filling material outside the root canal was noted. 10.54% of teeth with insufficient root canal filling depth and 6.64% of teeth with a missing root canal were also identified.CONCLUSIONS. There is a decrease in the incidence of the most common errors of endodontic treatment. The method of cone beam computed tomography is important at the stage of diagnosis and planning of endodontic treatment to assess the features of the internal structure of the tooth.

Stage-specific modulation of multinucleation, fusion, and resorption by the long non-coding RNA DLEU1 and miR-16 in human primary osteoclasts

Osteoclasts are the only cells able to resorb all the constituents of the bone matrix. While the modulation of osteoclast activity is well established for preventing bone-related diseases, there is an increasing demand for novel classes of anti-resorption agents. Herein, we investigated non-coding RNA molecules and proposed DLEU1 and miR-16 as potential candidates for modulating osteoclast functions. DLEU1 and miR-16 target cell fusion at both the early and late stages of osteoclastogenesis but operate through independent pathways. DLEU1 silencing hinders the fusion process, leading to abrogation of the phagocytic cup fusion modality and a reduction in the fusion events between mononucleated precursors and multinucleated osteoclasts, while miR-16 influences monocyte-to-osteoclast differentiation, impairing osteoclasts formation but not the number of nuclei at early stages. On the other hand, using these non-coding RNAs to engineer mature osteoclasts has implications for bone resorption. Both DLEU1 and miR-16 influence the speed of resorption in pit-forming osteoclasts, without affecting the resorbed area. However, the impact of increasing miR-16 levels extends more broadly, affecting trench-forming osteoclasts as well, leading to a reduction in their percentage, speed, and resorbed area. These findings offer potential new therapeutic targets to ameliorate bone destruction in skeletal diseases.

Metabolic effects of quercetin on inflammatory and autoimmune responses in rheumatoid arthritis are mediated through the inhibition of JAK1/STAT3/HIF-1α signaling

BackgroundRheumatoid arthritis, a chronic autoimmune disease, is characterized by synovial hyperplasia and cartilage erosion. Here, we investigated the potential mechanism of action of quercetin, the main component of flavonoids, in treating rheumatoid arthritis.ObjectTo examine the anti-arthritic effects of quercetin and elucidate the specific mechanisms that differentiate its metabolic effects on autoimmune and inflammatory responses at the synovial cell level.MethodsWe created a collagen-induced arthritis (CIA) model in Wistar rats, which were administered quercetin (50 or 100 mg/kg) continuously for four weeks via stomach perfusion. The arthritis score, histopathological staining, radiological assessment, and serum biochemical parameters were used to study the impact of quercetin on disease improvement. Additionally, immunofluorescence was employed to detect JAK1/STAT3/HIF-1α expression in rat joints. Moreover, the effects of quercetin (20, 40, and 80 µmol/L) on the properties and behavior of synovial fibroblasts were evaluated in an in vitro MH7A cell model using flow cytometry, CCK8, and transwell assays. Further, the mRNA expression levels of inflammatory cytokines IL1β, IL6, IL17, and TNFα were assessed by quantitative real-time PCR. Glucose, lactate, lactate dehydrogenase, pyruvate, pyruvate dehydrogenase, and adenosine triphosphate assay kits were employed to measure the metabolic effects of quercetin on synovial fibroblasts. Finally, immunoblotting was used to examine the impact of quercetin on the JAK1/STAT3/HIF-1α signaling pathway in synovial fibroblasts.ResultsIn vivo experiments confirmed the favorable effects of quercetin in CIA rats, including an improved arthritis score and reduced ankle bone destruction, in addition to a decrease in the pro-inflammatory cytokines IL-1β, IL-6, IL-17, and TNF-α in serum. Immunofluorescence verified that quercetin may ameliorate joint injury in rats with CIA by inhibiting JAK1/STAT3/HIF-1α signaling. Various in vitro experiments demonstrated that quercetin effectively inhibits IL-6-induced proliferation of MH7A cells and reduces their migratory and invasive behavior, while inducing apoptosis and reducing the expression of the pro-inflammatory cytokines IL1β, IL6, IL17, and TNFα at the mRNA level. Quercetin caused inhibition of glucose, lactate, lactate dehydrogenase, pyruvate, and adenosine triphosphate and increased pyruvate dehydrogenase expression in MH7A cells. It was further confirmed that quercetin may inhibit energy metabolism and inflammatory factor secretion in MH7A cells through JAK1/STAT3/HIF-1α signaling.ConclusionsQuercetin’s action on multiple target molecules and pathways makes it a promising treatment for cartilage injury in rheumatoid arthritis. By reducing joint inflammation, improving joint metabolic homeostasis, and decreasing immune system activation energy, quercetin inhibits the JAK1/STAT3/HIF-1α signaling pathway to improve disease status.

A case of early-onset congenital syphilitic osteomyelitis of the calcaneus and literature review

BackgroundCongenital syphilis (CS) is a sexually transmitted disease caused by Treponema pallidum (TP). When the skeletal system is involved, it often results in multiple, symmetrical bone destruction at the epiphyses of long tubular bones such as the humerus and radius, rarely involving the calcaneus. This article reports a case of calcaneal osteomyelitis caused by TP in a child with no other bone damage and subtle clinical manifestations, No similar cases have been reported.Case presentationA 4-month-old male infant presented with right foot swelling without any obvious cause and no history of trauma. X-ray and CT scans showed bone loss in the calcaneus and surrounding soft tissue swelling. Review of past medical records revealed that the infant had been diagnosed with CS infection during a hospital stay for “pneumonia” at one month old. The parents refused surgery, opting for conservative treatment at an external hospital for three weeks, during which the symptoms of the affected foot showed no significant improvement. Subsequently, the child was treated at our hospital with surgery, including lesion removal and cast fixation, followed by oral antibiotic treatment. The last follow-up showed no swelling or tenderness in the affected foot, with good mobility, and X-rays indicated that the bone had essentially returned to normal.ConclusionsEarly CS rarely involves the calcaneus. When diagnosing unexplained calcaneal osteomyelitis in infants, this rare cause should be considered. A thorough medical history should be taken and a careful physical examination conducted. Once diagnosed, timely surgical debridement and appropriate antibiotic therapy targeting TP infection are required. Early identification and intervention can result in a good prognosis without related complications.

Magnetic resonance imaging classification in a percutaneous needle injury rat model of intervertebral disc degeneration

BackgroundDuring the development of disease-modifying intervertebral disc degeneration (IDD) drugs, the rat model of IDD is frequently used for disease progression assessment. The aim of this study was to describe a magnetic resonance (MRI) scoring system for the assessment of different disc conditions in puncture-induced IDD, allowing standardization and comparison of results obtained by different investigators.MethodsA total of 36 Sprague-Dawley rats were utilized in the present study. The animals were divided into two groups: a sham group and an IDD group caused by puncture. The rats in the IDD group were subsequently divided into six categories based on time frames, with five rats in each category. The sham group was divided into two sub-groups (n = 3) for 28 and 56 days, respectively. T2-weighted images of rats consecutively studied with MRI of the coccygeal discs were classified according to the time course using the corresponding histological data. Additional scoring of the micro-CT was employed to identify the progression of bone destruction of the rat model of IDD.ResultsA comparison of the MRI results between the sham group and the IDD group revealed a significant reduction in NP height, area, T2WI value, and DHI in the latter group (P < 0.05). The micro-CT results demonstrated that following acupuncture, there was a notable decline in the BV, Tb.N, and height of the coccygeal vertebra, while the BS/BV and Tb.Sp exhibited a significant increase (P < 0.05). The histological results were analogous to the MRI results, indicating a progressive exacerbation of IDD and a corresponding increase in NP score (P < 0.05). The results of the MRI were found to be consistent with those of the micro-CT and histological analyses (P < 0.05). The results of the study demonstrate a robust correlation between MRI analysis and histological findings. Live animals are employed for MRI analysis to improve experiment comparability. The reliability of the MRI scoring system ensures assessment of disease progression in live animals, while promoting cost savings and animal welfare by avoiding the sacrifice of animals at different times.ConclusionsThe described scoring paradigm has quantitatively been found to differentiate IDD disease progression in an in vivo rat model. Hence, we suggest employing it to evaluate the rat IDD model and assess the effects of treatments in this model.

Breast Cancer Bone Metastasis Therapy and Tumor‐Associated Bone Destruction Repair by Versatile Semiconducting Nanointegrators with X‐Ray Adjuvant

AbstractTumor progress and tumor‐associated osteolysis are two key issues of breast cancer bone metastasis, which makes it challenging for bone metastasis treatment. To settle these two issues concurrently, a versatile semiconducting nanointegrator (termed as SPNCpG/Ca) containing semiconducting polymer nanoparticle (SPN), Ca2+ and cytosine‐phosphate‐guanine (CpG) oligonucleotides conjugated on the surface via a singlet oxygen (1O2)‐responsive linker, is designed. The antitumor effect can be triggered with X‐ray irradiation as an adjuvant, in which SPN works as a radiosensitizer to produce 1O2 for radiotherapy and controlled release of CpG via disrupting 1O2‐responsive linkers. The Ca2+ accumulation via SPNCpG/Ca delivering causes tumor cell death and the released CpG activates immune response to realize immunotherapy. The combinational action of radiotherapy, Ca2+ overloading, and immunotherapy results in complete clearance of metastatic tumor cells in 4T1 breast cancer‐based bone metastasis mouse models. Furthermore, Ca2+ can accelerate osteogenesis of bone marrow mesenchymal stem cells while CpG inhibits osteoclast differentiation in the bone metastasis microenvironment to alleviate osteolysis, which synergistically contributes to repair of tumor‐associated bone destruction. SPNCpG/Ca represents a versatile therapeutic nanosystem with the abilities to treat bone metastasis and repair tumor‐associated bone destruction, providing a new tactic for bone metastasis therapy.

12460 Bilateral Parietal Thinning: A Rare Condition Of Unclear Etiology

Abstract Disclosure: T.L. Madsen-Barbosa: None. M. Cheikh: None. I. Marcano: None. Background: Bilateral parietal bone thinning (BPT) is an infrequent and often underdiagnosed condition characterized by the external thinning of the skull's parietal bone. The pathophysiology is unclear, but some studies suggest a link to osteoporosis. We present a case of osteoporosis diagnosed on evaluation of BPT. Case Description: A 77-year-old woman with a history of chronic kidney disease (CKD stage IV) and type 2 diabetes was referred to the Bone Health Clinic for evaluation of low bone density. She initially presented to Neurosurgery clinic for evaluation of head indentations. A dual energy x-ray absorptiometry (DEXA) scan showed values in osteopenia range (left total hip bone mineral density (BMD) 0.678 and T-score of -2.2, left femoral neck BMD 0.272 and T-score of -1.6, and left 33% radius BMD 0.577 and T-score of -2.0), leading to the referral. The patient reported painless indentations in the parietal bones that had been progressing for four years, with no history of head trauma, inflammatory disease, or prolonged steroid use. A head computed tomography (CT) scan showed symmetric thinning of the skull’s parietal bones, with an average thickness of 2.34 mm (compared to 5.1 mm four years earlier). Review of prior images also revealed a T11 compression fracture on spine X-ray from 2019. Laboratory tests showed elevated parathyroid hormone (PTH) 155 pg/mL (reference range 15-65 pg/mL), low vitamin D 25-OH 10.6 ng/mL (reference range 30-100 ng/mL), elevated alkaline phosphatase 142 units/L (reference range 46-116 units/L), and high creatinine level 2.7 mg/dL (reference range 0.5-0.8 mg/dL), other laboratory tests were normal. After discussion with the patient and Nephrology, Denosumab therapy along with Calcium and Vitamin D supplementation were started in November 2023. The patient continues the treatment with antiresorptive medication every 6 months and head CT scan to monitor the skull thinning changes. Discussion: BPT is rare, with only approximately 150 cases reported. Crucial aspects such as its etiology, pathophysiology, treatment, and prognosis remain unknown. It can result from various conditions like trauma, systemic mastocytosis, diabetes mellitus, hereditary diseases, or idiopathic causes and mainly affects women of advanced age. Osteoporosis is suggested as a possible cause based on histological findings on prior studies that propose BPT may result from osteoporosis-induced decreased bone formation rather than increased bone destruction. The reason for excessive bone resorption in the skull of osteoporotic patients remains unclear. Our case highlights progressive and symmetric BPT possibly related to systemic conditions like osteoporosis, with a focus on treatment options. Conclusion: This case sheds light on the clinical presentation, imaging findings, pathogenesis, and treatment options for the rare condition of bilateral parietal bone thinning. Presentation: 6/3/2024

7949 Unraveling a Unique Presentation of Paget’s Disease of Bone

Abstract Disclosure: S. Puri: None. L. Bovee: None. R. Narla: None. Background: Paget's Disease of Bone (PDB) is a disorder characterized by rapid bone destruction and repair, which results in distortion of bone architecture. PDB occurs most commonly in adults over 55 and of European descent. PDB presents with both lytic and sclerotic lesions, predominantly in the axial skeleton. Serum alkaline phosphatase (ALP) levels and bone turnover markers (BTMs) are typically elevated in PDB. Clinical Case: A 53-year-old African-American woman with a history of breast cancer, PTSD, depression, and obesity (BMI 37) presented with worsening back pain over the past six months. Her pain would start at the center of her back and radiate to her left lower extremity. She endorsed rapid weight loss and night sweats and had lumbar bony tenderness on exam, prompting a spinal MRI. Spinal MRI was significant for diffuse sclerosis of the L3 vertebral body only. The radiology report provided a broad differential for this finding, including metastases, lymphoma, infection, PDB, and hemangioma. Due to progression of the patient’s back pain and concern for possible malignancy, a whole-body SPECT was completed which showed isolated tracer uptake into the L3 vertebral body extending into the pedicles and spinous process. Similar findings were noted on bone scans dating back to 2001. Per the radiology report, the presence of sclerosis with minimal expansion is most suggestive of PDB. Endocrinology was consulted for guidance on treatment and surveillance imaging for this patient. The endocrinology team discussed the case with radiology, who confirmed that the patient’s imaging findings had classic features of PDB. Bone specific ALP (B-ALP) and procollagen type 1 amino-terminal propeptide (P1NP) as bone turnover markers (BTMs) were within normal limits. A DEXA scan is pending to evaluate for concurrent osteoporosis. Clinical Lessons: PDB was favored as the most likely diagnosis primarily due to the sclerotic appearance of the patient’s vertebral lesion on imaging, radicular symptoms, and exam finding of bony point tenderness. Other diagnoses, such as metastatic disease, were considered and were thought to be unlikely given that the vertebral lesion is monostotic and stable. This case highlights the necessity of carefully evaluating radiographic findings and clinical history in the diagnosis of PDB. In this case, the patient was from a demographic group unlikely to have PDB and, unexpectedly, did not have elevated BTMs. It is important to consider PDB on the differential diagnosis in cases such as this because PDB can present in myriad ways and in a variety of patient populations. Presentation: 6/2/2024

Efficacy and safety of intra-articular-only meropenem after one-stage revision for treating Escherichia coli-induced periprosthetic joint infection in a rat model.

The optimum type of antibiotics and their administration route for treating Gram-negative (GN) periprosthetic joint infection (PJI) remain controversial. This study aimed to determine the GN bacterial species and antibacterial resistance rates related to clinical GN-PJI, and to determine the efficacy and safety of intra-articular (IA) antibiotic injection after one-stage revision in a GN pathogen-induced PJI rat model of total knee arthroplasty. A total of 36 consecutive PJI patients who had been infected with GN bacteria between February 2015 and December 2021 were retrospectively recruited in order to analyze the GN bacterial species involvement and antibacterial resistance rates. Antibiotic susceptibility assays of the GN bacterial species were performed to screen for the most sensitive antibiotic, which was then used to treat the most common GN pathogen-induced PJI rat model. The rats were randomized either to a PJI control group or to three meropenem groups (intraperitoneal (IP), IA, and IP + IA groups). After two weeks of treatment, infection control level, the side effects, and the volume of antibiotic use were evaluated. Escherichia coli was the most common pathogen in GN-PJI, and meropenem was the most sensitive antibiotic. Serum inflammatory markers, weightbearing activity, and Rissing score were significantly improved by meropenem, especially in the IA and IP + IA groups ( p < 0.05). Meropenem in the IA group eradicated E. coli from soft-tissue, bone, and prosthetic surfaces, with the same effect as in the IP + IA group. Radiological results revealed that IA and IP + IA meropenem were effective at relieving bone damage. Haematoxylin and eosin staining also showed that IA and IP + IA meropenem improved synovial inflammation and bone destruction. No pathological changes in the main organs or abnormal serum markers were observed in any of the meropenem-treated rats. The IA group required the lowest amount of meropenem, followed by the IP and IP + IA groups. IA-only meropenem with a two-week treatment course was effective and safe for PJI control following one-stage revision in a rat model, with less meropenem use.

Aberrant NSUN2-mediated m5C modification of exosomal LncRNA MALAT1 induced RANKL-mediated bone destruction in multiple myeloma

The impact of exosome-mediated crosstalk between multiple myeloma (MM) cells and osteoclasts (OCs) on bone lesions remains to be investigated. Here, we identified NSUN2 and YBX1-mediated m5C modifications upregulated LncRNA MALAT1 expression in MM cells, which could be transported to OCs via exosomes and promote bone lesions. Methodologically, RNA-seq was carried out to detect the cargoes of exosomes. TRAP staining and WB were used to evaluate osteoclastogenesis in vitro. Micro-CT and bone histomorphometric analyses were performed to identify bone destruction in vivo. RNA pull-down, RIP, MeRIP, and luciferase reporter assays were used to test the interactions between molecules. The clinical features of MALAT1, NSUN2 and YBX1 were verified through public datasets and clinicopathological data analyses. Mechanistically, MALAT1 was the highest expressed lncRNA in U266 exosomes and could be transported to RAW264.7 cells. MALAT1 could enhance the differentiation of RAW264.7 cells into OCs by stimulating RANKL expression and its downstream AKT and MAPKs signaling pathways via a ceRNA mechanism. Additionally, MALAT1 could be modified by NSUN2, an m5C methyltransferase, which in turn stabilized MALAT1 through the “reader” YBX1. Clinical studies indicated a notable positive correlation between MALAT1, NSUN2, YBX1 levels and bone destruction features, as well as with RANKL expression.

Imaging approach for fungal sinusitis.

This article provides a comprehensive review of the computed tomography (CT) and magnetic resonance (MR) imaging findings of invasive fungal sinusitis with an emphasis on pattern recognition and approach to interpretation. Fungal sinusitis is categorized into invasive (acute, chronic, and granulomatous) and noninvasive forms (allergic fungal sinusitis and mycetoma). CT is superior for detecting bony erosion and hyperdense fungal elements, while MRI excels in evaluating soft tissue and mucosal involvement. Key radiologic signs such as bone destruction, sinus wall thickening, and 'black turbinate sign' aid in early diagnosis, especially in invasive cases. Early imaging signs can be subtle. Early detection is necessary, particularly in immunocompromised patients with acute invasive fungal sinusitis, where rapid intervention is critical. Pattern recognition and adequate interpretation of fungal sinusitis are possible using CT and MRI. Imaging can also help identify complications, aiding with reliable diagnosis and prompt intervention.

Application Value of Platelet-to-Lymphocyte Ratio as a Novel Indicator in Rheumatoid Arthritis: A Review Based on Clinical Evidence.

Rheumatoid arthritis (RA) is a chronically progressive autoimmune disease with increasing age-standardized prevalence and incidence of RA worldwide. Its pathological features are persistent synovitis of the joint, accompanied by the release of a large number of inflammatory cytokines and cartilage and bone destruction. RA can lead to progressive joint damage, stiffness and swelling, vascular and bone-related complications, and irreversible disability, which seriously affects patients' life treatment. Early diagnosis and treatment can enhance the quality of life of RA patients. Platelet-to-lymphocyte ratio (PLR), as a common indicator in routine blood tests, has been proposed as an indicator of systemic inflammation in recent years. Its clinical detection is less invasive, economical, rapid and simple, and has been applied to the clinical evaluation of a variety of diseases. Of note, this indicator is important in assessing disease activity in RA, co-diagnosing RA, detecting subclinical complications, and monitoring responses to anti-inflammatory therapy. Therefore, this review summarizes the relationship between PLR and RA and the relevant mechanisms, further advancing the understanding of the clinical value of PLR.

Research progress on the regulatory cell death of osteoblasts in periodontitis

Periodontitis is a chronic inflammatory disease characterized by progressive destruction of alveolar bone. The most critical mechanism underlying alveolar bone destruction is the imbalance of bone homeostasis, where osteoblast-mediated bone matrix synthesis plays an important role in regulating bone homeostasis. Regulated cell death is instrumental in both the inflammatory microenvironment and the regulation of bone homeostasis. Chronic inflammation, oxidative stress, and other factors can be directly involved in mitochondrial and death receptor-mediated signaling pathways, modulating B-cell lymphoma 2 family proteins and cysteine aspartic acid specific protease (caspase) activity, thereby affecting osteoblast apoptosis and alveolar bone homeostasis. Chronic inflammation and cellular damage induce osteoblast necroptosis via the RIPK1/RIPK3/MLKL signaling pathway, exacerbating the inflammatory response and accelerating alveolar bone destruction. Stimuli such as pathogenic microorganisms and cellular injury may also activate caspase-1-dependent or independent signaling pathways and gasdermin D family proteins, promoting osteoblast pyroptosis and releasing pro-inflammatory cytokines to mediate alveolar bone damage. Iron overload and lipid peroxidation in periodontitis can trigger ferroptosis in osteoblasts, impacting their survival and function, ultimately leading to bone homeostasis imbalance. This article focuses on the mechanism of periodontal disease affecting bone homeostasis through regulatory cell death, aiming to provide research evidence for the treatment of periodontitis and alveolar bone homeostasis imbalance.

A size-switchable microsphere loaded with salmon calcitonin as two-weekly dosing for osteoporosis therapy

Osteoporosis is a disease with an increased incidence of fractures due to decreased bone mass and destruction of the microstructure of bone tissue. Salmon calcitonin (sCT), as a peptide, possesses the ability to inhibit osteoclast activity and thus regulate bone metabolism in clinical. However, short half-life and unstable physicochemical properties leading to rapid degradation of sCT have severely limited its clinical application. In this study, a size-switchable microsphere was developed to solve the problem of frequent administration and poor stability of sCT. sCT was encapsulated into Egg PC to form anhydrous reverse micelles (ARM) and then ARM was encapsulated into microspheres (MS@ARM). The degradable composite microspheres were utilized to provide a drug reservoir for sustained release of ARM encapsulated with sCT to reduce the frequency of drug administration, while the released ARM encapsulated with sCT entered the blood circulation to further protect sCT. In vitro release experiments demonstrated that the microspheres could sustain the release of sCT for at least 16 days. The microspheres MS@ARM showed the advanced therapeutic effect on the mouse model of glucocorticoid-induced osteoporosis (GIOP) at a low dosing frequency. The size-switchable microsphere is expected to be a new strategy for delivering sCT for osteoporosis treatment.