Anti-Osteoporosis Is Imperative in Prevention of Progress of Ankylosing Spondylitis

Background

Ankylosing spondylitis (AS) is a chronic autoimmune disease that affects the spine and peripheral joints, often leading to kyphosis, joint stiffness, and even ankylosis. Sagittal parameters, such as total thoracic kyphosis (TTK), thoracic kyphosis (TK), major thoracic kyphosis (MTK), and thoracolumbar kyphosis (TLK), are crucial indices for evaluating spinal alignment in AS patients and can reflect disease progression. This study aims to explore the relationship between bone mineral density (BMD), sagittal parameters, and joint ankylosis in AS patients.

Methods

A retrospective study was conducted on 147 AS patients. Participants were divided into three groups based on cervical and hip joint mobility. BMD was measured using quantitative computed tomography (QCT). Sagittal parameters (TTK, TK, MTK, TLK) were assessed using X-rays. Ordinal multinomial logistic regression and Spearman correlation analyses were performed to identify factors influencing joint stiffness.

Results

Significant differences in age, BMD, and sagittal parameters (TTK, TK, MTK, TLK) were observed among the groups. Ordinal logistic revealed that BMD (Estimate = 0.012) was negatively correlated with joint stiffness, while TTK (Estimate = 0.020) and TLK (Estimate = 0.030) were positively correlated. Age, TK, and MTK do not have a significant impact on joint stiffness. Spearman analysis showed no correlation between BMD and sagittal parameters (TTK and TLK). Besides, TTK and TLK were correlated.

Conclusion

In AS patients, BMD is an independent protective factor against joint stiffness, whereas sagittal parameters (TTK and TLK) contribute to increased joint stiffness. These findings highlight the importance of monitoring both bone mineral density and key sagittal parameters in clinical practice. Early anti-osteoporosis treatment, alongside interventions targeting abnormal spinal alignment, may help preserve joint mobility and potentially prevent progression to joint ankylosis.

A review of bacterial and osteoclast differentiation in bone infection

Bone infections are characterized by bacterial invasion of the bone microenvironment and subsequent bone structure deterioration. This holds significance because osteoclasts, which are the only cells responsible for bone resorption, are abnormally stimulated during bone infections. Multiple communication factors secreted by bone stromal cells regulate the membrane of osteoclast progenitor cells, thereby maintaining bone homeostasis through the expression of many types of receptors. During infection, the immunoinflammatory response triggered by bacterial invasion and multiple virulence factors of bacterial origin can disrupt osteoclast homeostasis. Therefore, clarifying the pathways through which bacteria affect osteoclasts can offer a theoretical basis for preventing and treating bone infections. This review summarizes studies investigating bone destruction caused by different bacterial infections. In conclusion, bacteria can affect osteoclast metabolic activity through multiple pathways, including direct contact, release of virulence factors, induction of immunoinflammatory responses, influence on bone stromal cell metabolism, and intracellular infections.

Microbial chaperonin 60 inhibits osteoclast differentiation by interfering with RANK/RANKL binding and overexpression of lipocalin2

Osteoclasts play a crucial role in bone destruction in rheumatoid arthritis (RA). This study aimed to investigate the inhibitory effects of chaperonin 60 (CPN60), identified in the surface proteins of Propionibacterium freudenreichii MJ2, on receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation, and elucidate the underlying mechanisms. Treatment with CPN60 inhibited RANKL-induced osteoclast differentiation by decreasing the expression of osteoclast differentiation-related genes and proteins. CPN60 interfered with the binding of RANKL to RANK, as elucidated using surface plasmon resonance (SPR) and immunofluorescence. In silico molecular docking analysis further supported the interference of CPN60 with the binding of RANKL and RANK. CPN60 suppressed the expression of molecules linked to the calcium-dependent pathway in RANKL-induced osteoclast differentiation at both mRNA and protein levels. Microarray analysis showed elevated expression of lipocalin 2 (Lcn2), which was closely linked to the inhibition of osteoclast differentiation in CPN60-treated RAW 264.7 cells. Inhibition of Lcn2 decreased the inhibitory effect of CPN60 on osteoclast differentiation, indicating that increased expression of Lcn2 by CPN60 contributes to the inhibition of osteoclastogenesis. In addition, CPN60 treatment alleviated arthritis symptoms in collagen-induced arthritis mice by reducing the generation of collagen-specific antibodies and inhibiting osteoclast differentiation. In conclusion, CPN60 of P. freudenreichii MJ2 interfered with RANKL-RANK binding, reduced the expression of genes and proteins related to osteoclast differentiation and upregulated Lcn2 expression, thereby inhibiting RANKL-induced osteoclast differentiation, which might contribute to ameliorate collagen-induced arthritis.

Effect of Acupuncture Treatment on the Ocular Pain, Mental State and Ocular Surface Characteristics of Patients with Dry Eye Disease: A Non-Randomized Pilot Study

Background

Ocular pain is a prevalent symptom of dry eye disease (DED), which often accompanies potential psychological issues. The study aimed to explore whether acupuncture could improve ocular pain, mental state, and dry eye parameters in patients with DED.

Methods

The non-randomized pilot study included 48 patients divided into two groups: the acupuncture group (n=27) and the 0.3% sodium hyaluronate (SH) group (n=21). Participants in the acupuncture group underwent treatments on six bilateral acupuncture points (BL1, BL2, ST1, LI 20, SI1 and SI3) 3 times per week for 4 weeks. Patients in the SH group received 0.3% SH 4 times per day for 4 weeks. Ocular pain was assessed using the numerical rating scale (NRS), and mental state was evaluated through the self-rating anxiety scale (SAS) and self-rating depression scale (SDS). Ocular surface parameters, concentrations of inflammatory cytokines, and corneal nerve morphological indicators were measured at baseline, the first week, and the fourth week. Randomization procedures were not used in this study, and outcome assessors and statistical analysts were blinded.

Results

Compared with baseline, both NRS scores (from 5.91 ± 1.52 to 1.94 ± 1.57) and ocular surface discomfort index (OSDI) scores (from 49.75 ± 14.92 to 29.64 ± 18.79) were decreased after 1 and 4 weeks of treatment in both groups (all p < 0.05). At 4 weeks, the acupuncture group showed significant improvements, including increased tear break-up time (TBUT) and corneal perception, decreased SAS and SDS scores, and reduced concentrations of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α concentration in tears (all p < 0.05). These changes were not observed in the SH group (all p > 0.05).

Conclusion

Acupuncture treatment could improve ocular surface characteristics in patients with DED, and more importantly, it alleviates their ocular pain and depressive state. The anti-inflammatory effect of acupuncture may be involved in this process. Future research with larger, randomized controlled trials (RCTs) is necessary to confirm these findings and clarify the mechanisms involved.

Positive Effects of Biologics on Osteoporosis in Rheumatoid Arthritis

Osteoporosis is a systemic skeletal disorder that causes vulnerability of bones to fracture owing to reduction in bone density and deterioration of the bone tissue microstructure. The prevalence of osteoporosis is higher in patients with autoimmune inflammatory rheumatic diseases, including rheumatoid arthritis (RA), than in those of the general population. In this autoimmune inflammatory rheumatic disease, in addition to known risk factors for osteoporosis, various factors such as chronic inflammation, autoantibodies, metabolic disorders, drugs, and decreased physical activity contribute to additional risk. In RA, disease-related inflammation plays an important role in local or systemic bone loss, and active treatment for inflammation can help prevent osteoporosis. In addition to conventional synthetic disease-modifying anti-rheumatic drugs that have been traditionally used for treatment of RA, biologic DMARDs and targeted synthetic DMARDs have been widely used. These agents can be employed more selectively and precisely based on disease pathogenesis. It has been reported that these drugs can inhibit bone loss by not only reducing inflammation in RA, but also by inhibiting bone resorption and promoting bone formation. In this review, the pathogenesis and research results of the increase in osteoporosis in RA are reviewed, and the effects of biological agents on osteoporosis are discussed.

Osteoclasts in Tumor Biology: Metastasis and Epithelial-Mesenchymal-Myeloid Transition

Osteoclast is a specialized cell that originates from monocytic lineage, communicates closely with osteoblasts under physiological conditions, participates in bone modeling and re-modeling, contributes to calcium homeostasis and osteoimmunity. In pathological conditions, it is involved in many tumors such as giant cell bone tumor (osteoclastoma), aneurysmal bone cyst, osteosarcoma, and metastatic cancers, and it usually causes local spread and progression of the tumor, working against the host. Since osteoclasts play an active role in primary bone tumors and bone metastases, the use of anti-osteoclastic agents significantly reduces the mortality and morbidity rates of patients by preventing the progression and local spread of tumors. Osteoclasts also accompany undifferentiated carcinomas of many organs, especially pancreas, thyroid, bladder and ovary. Undifferentiated carcinomas rich in osteoclasts have osteoclastoma-like histology. In these organs, osteoclastoma-like histology may accompany epithelial carcinomas, and de novo, benign and borderline tumors. Mature and immature myeloid cells, including osteoclasts, play an active role in the tumor progression in primary and metastatic tumor microenvironment, in epithelial-mesenchymal transition (EMT), mesenchymal-epithelial-transition (MET), and cancer stem cell formation. Additionally, they are the most suitable candidates for cancer cells in cell fusion due to their evolutionary fusion capabilities. Myeloid features and markers (CD163, CD33, CD68 etc.) can be seen in metastatic cancer cells. Consequently, they provide metastatic cancer cells with motility, margination, transmigration, chemotaxis, phagocytosis, angiogenesis, matrix degradation, and resistance to chemotherapy. For these reasons, we think that the concept of Epithelial-Mesencyhmal-Myeloid-Transition (EMMT) will be more accurate than EMT for cancer cells with myeloid properties.

Comparison of Biocompatibility of Calcium Silicate-Based Sealers and Epoxy Resin-Based Sealer on Human Periodontal Ligament Stem Cells

The aim of this study was to evaluate the biocompatibility of calcium silicate-based sealers (CeraSeal and EndoSeal TCS) and epoxy resin-based sealer (AH-Plus) in terms of cell viability, inflammatory response, expression of mesenchymal phenotype, osteogenic potential, cell attachment, and morphology, of human periodontal ligament stem cells (hPDLSCs). hPDLSCs were acquired from the premolars (n = 4) of four subjects, whose ages extended from 16 to 24 years of age. Flow cytometry analysis showed stemness of hPDLSCs was maintained in all materials. In cell viability test, AH-Plus showed the lowest cell viability, and CeraSeal showed significantly higher cell viability than others. In ELISA test, AH-Plus showed higher expression of IL-6 and IL-8 than calcium silicate-based sealers. In an osteogenic potential test, AH-Plus showed a lower expression level than other material; however, EndoSeal TCS showed a better expression level than others. All experiments were repeated at least three times per cell line. Scanning electronic microscopy studies showed low degree of cell proliferation on AH-Plus, and high degree of cell proliferation on calcium silicate-based sealers. In this study, calcium silicate-based sealers appear to be more biocompatible and less cytotoxic than epoxy-resin based sealers.

Bone Diseases in Patients with Chronic Liver Disease

Osteoporosis is a frequently observed complication in patients with chronic liver disease, particularly liver cirrhosis and cholestatic liver diseases. In addition, osteoporosis is critical in patients receiving a liver transplant. Nevertheless, few studies have evaluated bone diseases in patients with more frequently observed chronic liver disease, such as chronic viral hepatitis, nonalcoholic fatty liver disease and alcoholic liver disease. Osteoporosis is a disease caused by an imbalance in the activities of osteoblasts and osteoclasts. Over the last few decades, many advances have improved our knowledge of the pathogenesis of osteoporosis. Importantly, activated immune cells affect the progression of osteoporosis, and chronic inflammation may exert an additional effect on the existing pathophysiology of osteoporosis. The microbiota of the intestinal tract may also affect the progression of bone loss in patients with chronic liver disease. Recently, studies regarding the effects of chronic inflammation on dysbiosis in bone diseases have been conducted. However, mechanisms underlying osteoporosis in patients with chronic liver disease are complex and precise mechanisms remain unknown. The following special considerations in patients with chronic liver disease are reviewed: bone diseases in patients who underwent a liver transplant, the association between chronic hepatitis B virus infection treatment and bone diseases, the association between sarcopenia and bone diseases in patients with chronic liver disease, and the association between chronic liver disease and avascular necrosis of the hip. Few guidelines are currently available for the management of low bone mineral density or bone diseases in patients with chronic liver disease. Due to increased life expectancy and therapeutic advances in chronic liver disease, the importance of managing osteoporosis and other bone diseases in patients with chronic liver disease is expected to increase. Consequently, specific guidelines need to be established in the near future.

In Vitro Comparison of Biocompatibility of Calcium Silicate-Based Root Canal Sealers

The aim of this study was to assess the effect of three calcium silicate-based sealers (EndoSeal MTA, Nano-ceramic Sealer, and Wellroot ST) and two epoxy resin-based sealers (AH-Plus, AD Seal) on various aspects, such as cell viability, inflammatory response, and osteogenic potential, of human periodontal ligament stem cells (hPDLSCs). AH-Plus showed the lowest cell viability on hPDLSCs in all time periods in fresh media. In set media, hPDLSCs showed no significant differences in cell viability among all the tested materials. Wellroot ST showed the highest level of cell adhesion and the morphology of attached cells. AH-plus presented a significantly higher expression of IL-6 and IL-8 than the other sealers. AD Seal and three calcium silicate sealers showed high expression of the mesenchymal stem cell markers. ALP mRNA expression showed a significant increase in time-dependent manner on all of three calcium silicate-based sealers, which do not seem to interfere with the differentiation of hPDLSCs into osteoblasts. Based on the results from this study, calcium silicate-based sealers appear to be more biocompatible and less cytotoxic than epoxy resin-based sealers. Meanwhile, further and long-term clinical follow-up studies are required.