Tartrate-resistant Acid Phosphatase Research Articles

Optimizing Ligand Valency to Maximize Tendon Accumulation of Peptide-Targeted Nanoparticles.

In many tissues, including musculoskeletal tissues such as tendon, systemic delivery typically results in poor targeting of free drugs. Hence, we previously developed a targeted drug delivery nanoparticle (NP) system for tendon healing, leveraging a tartrate resistant acid phosphatase (TRAP) binding peptide (TBP) ligand. The greatest tendon targeting was observed with NPs functionalized with 30 000 TBP ligands per NP at day 7 during the proliferative healing phase, relative to the inflammatory (day 3) and early remodeling (day 14) phases of healing. Nevertheless, TRAP activity varies throughout healing and, therefore, may offer an opportunity for optimizing temporal therapeutic targeting through multivalent interactions. Hence, in this study, we hypothesized that the ligand density (9000-55,000 TBPs per NP) can optimize tendon accumulation on the basis of variable TRAP levels. The multivalent nanoparticles were loaded with three different fluorophores. In vitro, the ligand density and fluorophore had no effect on the physicochemical properties of the NPs, including size, charge, polydispersity index, or dye loading efficiency; however, the TRAP binding affinity correlated positively with the ligand density. In vivo, the ligand density correlated positively with NP homing and retention in the tendon, establishing opportunities to leverage ligand density for tendon targeting across the tendon healing cascade, during aging, and in other tendon pathologies, including tendinopathies.

Utilization of Bone Alkaline Phosphatase (BAP) and Tartrate Resistant Acid Phosphatase (TRAP) as Biomarkers of Eggshell Quality and Bone Metabolism in Broiler Breeders and Progeny.

Eggshell breakage and broiler bone disorders are major problems for the breeder and broiler industries which are linked to mineral metabolism and animal genetics. The purpose of this work was to discover the link between individual animal phenotypic differences in mineral metabolism against concentrations of novel plasma biomarkers including tartrate resistant acid phosphatase (TRAP) and bone alkaline phosphatase (BAP). A subset of hens were selected from a flock of Cobb 500 breeders with the best or worst eggshell quality based upon dual energy x-ray absorptiometry (DEXA) and specific gravity (SG). Breeders were defined as having good eggshell quality (SG ≥ 1.080), or poor eggshell quality (SG < 1.080). Progeny hatched from breeders with good or poor eggshell quality were reared to 2 week of age and blood and bone samples were obtained after euthanasia. In both breeders and progeny, plasma concentrations of BAP and TRAP were measured, and bone mineral density was evaluated by DEXA. Results showed that breeders selected for eggshell quality had significantly different plasma concentrations of BAP (Good = 326.5 pg/mL, Poor = 253.2 pg/mL), and TRAP activity (Good = 2203 U, Poor = 4985 U). Breeders selected for eggshell quality produced progeny with different bone breaking strength (Good = 1.61 kg/mm, Poor = 1.47 kg/mm), tibia ash (Good = 45.9%, Poor = 42.2%), plasma BAP (Good = 372.3 pg/mL, Poor = 312.4 pg/mL), and lower plasma TRAP activity (Good = 18010 U, Poor = 23590 U). These data suggest that there is a strong correlation between the eggshell quality of breeders, performance and bone strength of progeny, and plasma of concentrations of BAP and TRAP in both breeder hens and progeny.

Gu Sui Bu (Drynaria fortunei J. Smith) prevents osteoporosis in ovariectomized rats by inhibiting pyroptosis through NLRP3/GSDMD/CASPASE-1

Traditional Chinese medicine Gu Sui Bu (Drynaria fortunei J. Smith) has the effect of tonifying the kidneys and strengthening bone. There are many modern studies on the anti-osteoporosis pharmacological mechanism of Drynariae, but no reports on the pharmacological mechanism of Drynariae improving cell pyroptosis and anti-osteoporosis have been found. AimThis study aims to verify the changes in cellular standard indicators in postmenopausal osteoporosis, thereby revealing the participating mechanism of pyroptosis and the intervention effect of Gu Sui Bu (Drynaria fortunei J. Smith) . MethodsDrynariae was subjected to UHPLC-Q-Orbitrap-MS/MS analysis, and the OVX rat model was constructed in vivo as the research object. It was divided into sham operation group (SHAM), ovariectomized osteoporosis model group (OVX) and bone fragmentation. Supplementary drug group (TFRD-L, TFRD-H). After 3 months of modeling, the medication group was treated with Drynariae and the samples were collected after 12 weeks of intervention. ELISA was used to detect the levels of Caspase-1, NLRP3, GSDMD, IL-1β, and IL-18 in rat serum; the right femur was taken for Micro-CT large bone microstructure scanning and femoral BMD detection; the femur was subjected to rat histopathology HE, TRAP staining; immunohistochemistry and immunofluorescence staining of rat histopathology were performed. WB and PCR were used to observe the expression of cell pyroptosis-related indicators Caspase-1, NLRP3, GSDMD and RUNX2, IL-1β, and IL-18. ResultsUHPLC-Q-Orbitrap-MS/MS analysis the main compounds in Gu Sui Bu (Drynaria fortunei J. Smith) samples were identified. These 9 chemical components are Palmitic acid, Fisetin, Caffeic acid, Naringin, Rutin, Uridine, Cafestol, Astilbin . Rat Micro-CT, The results of HE staining and TRAP showed that compared with the rats in the OVX group, the number of bone trabeculae in the rats in the Gu Sui Bu (Drynaria fortunei J. Smith) medication group (TFRD-L, TFRD-H) increased, became wider and thicker, and the bone density increased. Continuity increases and bone lacunae decrease. Rat serum ELISA, femoral tissue immunohistochemistry, immunofluorescence staining and WB, PCR showed that compared with the OVX group, Caspase-1, NLRP3, The expression levels of GSDMD and inflammation were reduced (p<0.05), and the expression of osteogenic marker RUNX2 was reduced and increased (p<0.05). ConclusionThe traditional Chinese medicine Gu Sui Bu (Drynaria fortunei J. Smith) can improve the bone density of ovariectomized osteoporosis model rats and significantly enhance the bone microstructure. At the same time, it reduced the expression of rat cell pyroptosis markers Caspase-1, NLRP3, and GSDMD in vivo, confirming that Gu Sui Bu (Drynaria fortunei J. Smith) may play an anti-osteoporosis effect through the NLRP3/GSDMD/Caspase-1 pathway.

Osteogenic CpG Oligodeoxynucleotide, iSN40, Inhibits Osteoclastogenesis in a TLR9-Dependent Manner

A CpG oligodeoxynucleotide (CpG-ODN), iSN40, was originally identified as promoting the mineralization and differentiation of osteoblasts, independent of Toll-like receptor 9 (TLR9). Since CpG ODNs are often recognized by TLR9 and inhibit osteoclastogenesis, this study investigated the TLR9 dependence and anti-osteoclastogenic effect of iSN40 to validate its potential as an osteoporosis drug. The murine monocyte/macrophage cell line RAW264.7 was treated with the receptor activator of nuclear factor-κB ligand (RANKL) to induce osteoclast differentiation, then the effect of iSN40 on was quantified by tartrate-resistant acid phosphatase (TRAP) staining and real-time RT-PCR. iSN40 completely inhibited RANKL-induced differentiation into TRAP+ multinucleated osteoclasts by suppressing osteoclastogenic genes and inducing anti-/non-osteoclastogenic genes. Treatment with a TLR9 inhibitor, E6446, or a mutation in the CpG motif of iSN40 abolished the intracellular uptake and anti-osteoclastogenic effect of iSN40. These results demonstrate that iSN40 is subcellularly internalized and is recognized by TLR9 via its CpG motif, modulates RANKL-dependent osteoclastogenic gene expression, and ultimately inhibits osteoclastogenesis. Finally, iSN40 was confirmed to inhibit the osteoclastogenesis of RAW264.7 cells cocultured with the murine osteoblast cell line MC3T3-E1, presenting a model of bone remodeling. This study demonstrates that iSN40, which exerts both pro-osteogenic and anti-osteoclastogenic effects, may be a promising nucleic acid drug for osteoporosis.

Inhibiting autophagy further promotes Ginkgolide B's anti-osteoclastogenesis ability

Excessive osteoclast activity could cause skeletal diseases including osteoporosis. Additionally, autophagy plays an initial role in osteoclast differentiation and function. Ginkgolide B (GB), a key compound in Ginkgo biloba, improves bone mass and suppresses mature osteoclast formation in vitro. This study examines the role of GB role in regulating osteoclast formation via autophagy. Using murine bone marrow-derived macrophages in vitro, we explored GB's effects on autophagy and osteoclast formation. We also assessed bone loss prevention in an ovariectomized (OVX) mouse model using GB combined with an autophagy inhibitor. Tartrate-resistant acid phosphatase staining was used to observe osteoclast formation. Autophagy-related proteins and intracellular microtubule associated protein 1 light chain 3 beta puncta were observed using western blotting and immunofluorescence. The impact of GB on OVX mice was evaluated using micro-computed tomography and hematoxylin and eosin staining. GB directly promoted autophagy in osteoclast precursors (OCPs), but inhibited osteoclast differentiation by reducing receptor activator of nuclear factor kappa B ligand (RANKL)-induced autophagy. GB inhibits the phosphorylation of RANKL downstream signaling pathways, such as Jun N-terminal kinase (JNK), p38, and extracellular signal-regulated kinase (ERK). Anisomycin (ANI), a JNK activator, reversed GB's inhibitory effects on RANKL-induced autophagy and osteoclastogenesis. Inhibiting autophagy using 3-Methyladenine (3-MA) or small interfering RNA significantly suppressed osteoclast differentiation both in vitro and in vivo. Our findings suggested that GB inhibits osteoclast formation by decreasing JNK phosphorylation and autophagy under RANKL stimulation. Interestingly, GB also directly promotes autophagy in OCPs. Thus, GB markedly reduces osteoclast differentiation and prevents bone loss, with its anti-osteoclastogenesis effect being enhanced by 3-MA. Accordingly, inhibiting GB-induced direct autophagy could further increase its therapeutic effect on bone disease resulting from excessive osteoclast activity.

TGF-β3 Restrains Osteoclastic Resorption Through Autophagy

While TGF-β3 promoted defect healing in a primate baboon skull defect model and patients, it remains unclear whether TGF-β3 affects the formation of osteoclasts and bone resorption between osteogenesis and osteolysis. Analysis of the full transcriptome of hPDLSCs (human periodontal ligament stem cells) revealed that the expression of RANKL was significantly up-regulated after TGF-β3 treatment during osteogenesis, which suggests its involvement in clock-controlled autophagy in bone metabolism. TRAP staining and bone resorption lacunae were used to assess the osteoclasts formed from RANKL-induced differentiated BMMs. During osteoclast differentiation, the characteristics of autophagy regulated by TGF-β3 were observed in BMMs through MDC staining, transmission electron microscopy, and LC3 immunofluorescence. The expression of related genes and proteins were detected on the sixth day in mCherry-EGFP-LC3B lentivirus-transfected BMMs using RT-qPCR and WB. Finally, a trans-well co-culture system was used to evaluate the effects of osteogenic differentiated hPDLSCs treated with TGF-β3 on the osteoclastic differentiation of BMMs. The results showed 10 ng/mL of TGF-β3 significantly suppressed osteoclastic differentiation and bone resorption in BMMs (p &lt; 0.05 vs. RANKL). In particular, TGF-β3 augments the expression of LC3-II to stimulate autophagy, consequently restraining osteoclastic resorption. These findings provide a molecular basis and are beneficial to illustrate the potential druggability of TGF-β3 in osteoporotic diseases.

Polyphyllin VI: A promising treatment for prostate cancer bone metastasis

Prostate cancer, as one of the most prevalent malignant tumors in men, seriously affects the prognosis and survival of patients due to its extremely high rate of bone metastasis. This study investigated the effect of Polyphyllin VI (PPVI) on metastatic bone disease for the first time in prostate cancer, focusing on its impact on osteoclast and tumor cell. In vitro studies utilized TRAP staining, ghost pen cyclic peptide staining, and bone resorption assays to evaluate the differentiation and function of receptor activator of nuclear factor-κB ligand (RANKL) induced and RM-1 conditional medium (CM) induced osteoclasts. The colony formation assay, wound healing assay, and Transwell assay were employed to analyze tumor cell proliferation, migration, and invasion in vitro. Flow cytometry was used to detect the cycling and apoptosis of tumor cells in vitro. Western Blot and PCR assays were conducted to assess the expression of genes. In vivo, micro-CT, hematoxylin-eosin staining, and immunohistochemical staining evaluated the impact of PPVI on bone destruction and tumor growth in a mouse model of tumor tibial metastasis. The study results indicated that PPVI effectively inhibited osteoclast differentiation, suppresses tumor cell proliferation, migration, and invasion in vitro, and induces apoptosis and G2/M phase arrest. In vivo, PPVI not only inhibits the growth of metastatic tumors but also mitigates the resulting bone destruction. These results suggest that PPVI holds significant potential as an alternative treatment for prostate cancer with bone metastasis, providing insights into its molecular mechanisms and therapeutic efficacy.

GDF15 propeptide promotes bone metastasis of castration-resistant prostate cancer by augmenting the bone microenvironment

BackgroundBone metastasis (BM) is a common and fatal condition in patients with castration-resistant prostate cancer (CRPC). However, there are no useful blood biomarkers for CRPC with BM, and the mechanism underlying BM is unclear. In this study, we investigated precise blood biomarkers for evaluating BM that can improve the prognosis of patients with CRPC.MethodsWe comprehensively examined culture supernatants from four prostate cancer (PCa) cell lines using Orbitrap mass spectrometry to identify specific proteins secreted abundantly by PCa cells. The effects of this protein to PCa cells, osteoblasts, osteoclasts were examined, and BM mouse model. In addition, we measured the plasma concentration of this protein in CRPC patients for whom bone scan index (BSI) by bone scintigraphy was performed.ResultsA total of 2,787 proteins were identified by secretome analysis. We focused on GDF15 propeptide (GDPP), which is secreted by osteoblasts, osteoclasts, and PCa cells. GDPP promoted the proliferation, invasion, and migration of PC3 and DU145 CRPC cells, and GDPP aggravated BM in a mouse model. Importantly, GDPP accelerated bone formation and absorption in the bone microenvironment by enhancing the proliferation of osteoblasts and osteoclasts by upregulating individual transcription factors such as RUNX2, OSX, ATF4, NFATc1, and DC-STAMP. In clinical settings, including a total of 416 patients, GDPP was more diagnostic of BM than prostate-specific antigen (PSA) (AUC = 0.92 and 0.78) and the seven other blood biomarkers (alkaline phosphatase, lactate dehydrogenase, bone alkaline phosphatase, tartrate-resistant acid phosphatase 5b, osteocalcin, procollagen I N-terminal propeptide and mature GDF15) in patients with CRPC. The changes in BSI over time with systemic treatment were correlated with that of GDPP (r = 0.63) but not with that of PSA (r = -0.16).ConclusionsGDPP augments the tumor microenvironment of BM and is a novel blood biomarker of BM in CRPC, which could lead to early treatment interventions in patients with CRPC.

S6K/FLNC/ITGβ3 signaling pathway regulates osteoclastogenesis and the inhibition of osteoclastogenesis by columbianadin

BackgroundOver-activation of osteoclastogenesis is a significant factor contributing to bone loss, leading to increased resorption of bone. Columbianadin (CBN), a compound derived from Angelicae Pubescentis Radix, has traditionally been used in Chinese medicine to treat bone-related disorders. However, the specific effects of CBN on bone loss are still poorly understood. Study designThis study aims to identify a novel target for inhibiting osteoclast differentiation and to elucidate the effects and underlying mechanisms of CBN on osteoclastogenesis. MethodsWe employed a transcriptomics approach to identify genes that undergo significant changes during osteoclast differentiation. These findings were validated using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot (WB) analysis. Subsequently, we utilized adenoviral transfection to investigate the effects of target genes on osteoclast differentiation. Additionally, we employed proteomics to elucidate the signaling pathways that regulate osteoclast differentiation. We examined the effect of CBN on S6K/FLNC/ITGβ3 signaling pathway and osteoclast differentiation. ResultsOur results revealed a dramatic increase in filamin C (FLNC) levels during osteoclast differentiation. Inhibition of FLNC expression significantly suppressed markers of osteoclast differentiation such as tartrate-resistant acid phosphatase (TRAP), nuclear factor-activated T cell 1 (NFATc1), and c-Fos, as well as inhibited the activity of bone resorption. We further conducted a proteomic analysis and found S6K protein might be involved in this process. Then we utilized an S6K-specific inhibitor (PF-4708671) and demonstrated that inhibiting the S6K protein reduced FLNC expression and the interaction between FLNC and integrin β3 (ITGβ3) in osteoclasts. Finally, we found that CBN inhibited osteoclast differentiation and bone loss in ovariectomized mice by targeting the S6K/FLNC/ITGβ3 signaling pathway. ConclusionFLNC was identified as a critical protein in osteoclastogenesis. The S6K/FLNC/ITGβ3 signaling pathway played a significant role in osteoclast differentiation and bone loss. Furthermore, CBN exhibited anti-osteoporotic effects by inhibiting the S6K/FLNC/ITGβ3 signaling pathway.

Leptin Promotes the Expression of Pro-inflammatory Mediator Genes but Does Not Alter Osteoclastogenesis and Early Stage Differentiation of Osteoblasts.

Leptin, a hormone secreted by adipose tissue, plays a pivotal role in maintaining energy metabolism and bone quality. Dysregulation of leptin can lead to the development of various pathological conditions. For example, the concentration of leptin is increased in individuals with obesity, and this increased concentration is positively correlated with higher bone mass. In addition, mice lacking leptin or the leptin receptor exhibit substantial bone loss, further highlighting the pivotal role of leptin in regulating bone metabolism. However, the precise mechanism through which leptin affects bone remodeling remains unclear. The present study investigated the effect of leptin on osteoclastogenesis and osteoblastogenesis. Osteoblasts derived from MC3T3-E1 cells and osteoclasts derived from RAW 264.7 cells were used. The findings revealed that leptin did not substantially affect osteoclastogenesis or osteoblastogenesis. Furthermore, leptin did not affect cell viability during osteoclast differentiation. The expression of inflammatory mediators was increased in differentiating RAW 264.7 cells. However, the expression of critical bone resorptive genes, including Ctsk and tartrate-resistant acid phosphatase, was not elevated following leptin stimulation. By contrast, leptin did not alter the expression of key osteogenic genes in preosteoblasts in the early stage of differentiation. These data demonstrate that leptin can stimulate the expression of pro-inflammatory mediators in differentiating osteoclasts. These changes do not affect osteoblastogenesis or osteoclastogenesis. Leptin may downregulate bone resorption and enhance mineralization to increase bone mass.

Serum bone turnover markers were associated with bone mass in late prepuberty and early puberty.

To analyse the association between bone turnover markers and bone mass in children and young adults. This descriptive study followed 132 children (68 boys/64 girls) from Malmö, Sweden, as controls in a school-based intervention study (2000-2017). Height, weight, Tanner stage and bone mass were measured annually from ages 8 to 15 years, with follow-ups at 19 and 23 years of age. Serum markers for bone formation (bone-specific alkaline phosphatase (bALP), N-terminal propeptide of collagen type 1 (PINP), osteocalcin) and resorption (C-terminal telopeptide crosslinks (CTX), tartrate-resistant acid phosphatase (TRAcP 5b)) were collected at ages 9.9 ± 0.6 (mean ± SD) (n = 78), 12.0 ± 0.6 (n = 64), 14.9 ± 0.8 (n = 52), 18.8 ± 0.3 (n = 34) and 23.3 ± 0.6 years (n = 56). Compared to girls, boys showed higher bone turnover markers at ages 15, 19 and 23 years (all p < 0.05). At 10 years of age (Tanner stage 1 and 2), bALP and TRAcP 5b correlated with current bone mass (adjusted for age and sex), while bALP, PINP, osteocalcin and CTX correlated with bone mass change over the next 2 years (adjusted for age, sex and interval) (all p < 0.05). Bone turnover markers in early Tanner stages predicted both current bone mass and subsequent bone mass changes.

Association of obstructive sleep apnea with bone metabolism in older adults: a hospital-based study

PurposeObstructive sleep apnea (OSA) significantly affects patients’ quality of life; however, the mechanisms, such as its effects on bone mineral density (BMD) and bone turnover marker (BTM) expression, remain unclear. In this study, we investigated the relationships among OSA, BMD, and (BTMs) in older adults.MethodsThis retrospective study enrolled 260 participants (114 women; 44.5%). Data of an established system (Alice NightOne) were used to diagnose OSA and analyze nocturnal hypoxia. Participants were divided into four groups according to respiratory event index (REI) (control, < 5 times/hour; mild OSA, 5–15 times/hour; moderate OSA 15–30 times/hour; severe OSA ≥ 30 times/hour). BMD were mesured by dual-energy x-ray absorptiometry. BTMs including bone specific alkaline phosphatase (BALP), tartrate-resistant acid phosphatase 5b (TRAP-5b) were collected.ResultsPatients with OSA had higher BMD at first lumbar vertebra, left and right femur than those without (all p < 0.05). REI was positively correlated with BMD at the first lumbar vertebra (r = 0.181, p = 0.006), left femur (r = 0.160, p = 0.014), and right femur (r = 0.243, p < 0.001). In participants with body mass index (BMI) of 18–24 kg/m2 (N = 96), the correlation between REI and BMD at the left femur(r = 0.251, p = 0.019) and right femur (r = 0.258, p = 0.018) remained. Multiple regression analysis showed that OSA was significantly associated with osteoporosis (p = 0.034, 95% confidence interval, 0.092–0.100, odds ratio, 0.092). MSaO2 was positively correlated with TRAP5b (r = 0.560, p = 0.007). In participants with a BMI of ≥ 24 kg/m2(N = 164), MSaO2 was negatively correlated with BALP (r = −0.331, p = 0.034). No significant association between REI and BMD was observed.ConclusionsOSA and hypoxia were associated with higher BMD in older adults in BMI of 18–24 kg/m2 but not in participants with a BMI of ≥ 24 kg/m2. This study suggests a negative association between OSA and osteoporosis in non-overweight and obese population. BMI played an important role. The study’s findings could help exploration mechanisms of osteoporosis and promoting its treatment.

A rare case of late-onset spondyloenchondrodysplasia with immune dysregulation presenting as adult-onset monogenic lupus.

Spondyloenchondrodysplasia is classified as an interferonopathy resulting from recessive mutations in the ACP5 gene and manifests with various clinical features, including distinctive skeletal dysplasia, neurological abnormalities, immune dysfunction resembling systemic lupus erythematosus (SLE) and Sjogren's syndrome. While SLE is typically considered multifactorial and more prevalent in adulthood, a subset of approximately 10%-25% of childhood cases arise from monogenic form. Among these, spondyloenchondrodysplasia accounts for only a rare fraction of monogenic lupus cases, with only 22 reported instances in the literature. This paper presents a new case of spondyloenchondrodysplasia-immune dysregulation (SPENCDI) in an adult patient born to nonconsanguineous parents. The patient was diagnosed with SPENCDI and exhibited immune neutropenia, anti-dsDNA positivity, platyspondyly, immune deficiency, and a homozygous variant (c.155A > C, p. Lys52Thr) in the ACP5 gene, previously classified as pathogenic. Notably, the patient achieved successful clinical management through the initiation of baricitinib treatment, a Janus kinase inhibitor. SPENCDI represents an uncommon cause of SLE in adulthood. Clinicians should be vigilant of underlying Mendelian inheritance when encountering patients with associated features. While treatments for both Mendelian and non-Mendelian SLE are similar, Janus kinase inhibitors like baricitinib show potential for managing interferon-signature monogenic SLE cases.

Bioflavonoid Tangeretin regulates RANK/RANKL/OPG Signaling Proteins via Stimulating Estrogenic Activity in Ovariectomized Rats

Background: Globally, osteoporosis has arisen as a significant health hazard, impacting over 200 million individuals. It is often reported in women, especially those who are in the postmenopausal stage. Even though numerous reasons are linked with osteoporosis etiology, estrogen deprivation is the prime inducer of osteoporosis. Purpose: The present research was intended to detect the bioflavonoid tangeretin potency against ameliorating osteoporosis in ovariectomized rats. Methods: Ovariectomy was performed in healthy female Sprague rats and treated with two different doses of the drug tangeretin. The body weight gain obtained by the experimental animals was noted throughout the experimental period. The uterus and vagina, the organ responsible for estrogen production and activity, were measured. Bone mineral density (BMD) and biomechanical properties of the femur were evaluated to study the impact of tangeretin. Bone biomarkers estradiol, bone GLA protein, and acid phosphatase were quantified to assess the impact of tangeretin on bone turnover. Serum phosphorous, calcium, creatinine, and tartrate-resistant acid phosphatase (TRAP), which are the osteoporosis risk factors, were analyzed in tangeretin-treated ovariectomized rats. Signaling proteins involved in the receptor activator of nuclear factor-κB (RANK)/receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) pathway, which is responsible for bone turnover, were quantified. Results: Tangeretin treatment significantly inhibited excess weight gain and increased the uterus and vaginal weight. BMD and biomechanical analysis of the femur prove tangeretin treatment increased the BMD and upgraded the biomechanical properties in ovariectomized animals. Tangeretin increased the estradiol and decreased the bone GLA protein and acid phosphatase. It also increased serum phosphorous, calcium, and creatinine and decreased the TRAP levels, confirming its ameliorative potency against bone turnover. It inhibited RANKL protein and increased the levels of OPG and its signaling molecules in ovariectomized rats. The anti-inflammatory bioflavonoid tangeretin attenuated the inflammatory stimulating cytokines in ovariectomized rats. Conclusion: Overall, our analysis confirms tangeretin possesses antiosteoporotic potency which effectively elevates estradiol and attenuates the bone turnover signaling pathway RANK/RANKL/OPG proteins in ovariectomized rats. The results of our research prove the establishment of a treatment strategy using tangeretin can improve bone health and prevent osteoporosis in menopausal women.

Nuciferine inhibits osteoclast formation through suppressing glycolysis metabolic programming and ROS production.

Nuciferine (NCF) is a bioactive compound from lotus leaves and has been proven to prevent osteoclastogenesis and ovariectomy-induced osteoporosis by our previous research. However, the underlying mechanism is still unclear. In this research, Raw264.7 cells were induced into osteoclast with or without NCF. CCK-8 and Edu assays were performed to detect the effects of 30 μM NCF on cell viability and proliferation. TRAP staining and bone resorption assays were performed to observe the role of NCF in osteoclastogenesis and bone resorption. RT-PCR and Western blot were performed to detect the effects of NCF on osteoclast-related genes, glycolysis-related genes, and reactive oxygen species (ROS)-related genes. Seahorse assays, lactate concentration and glucose consumption were performed to observe cell metabolism change. DCFH-DA fluorescent probe was used to detect ROS level. In this work, 30 μM NCF could not influence cell viability and cell proliferation. Osteoclast differentiation could be inhibited by 30 μM NCF. Bone resorption assay could also observe that bone resorption ability was successfully inhibited by 30 μM NCF. In seahorse assay, we discovered that NCF could decrease extracellular acid rate and increase oxygen consumption. RT-PCR and Western blot results showed that NCF could decrease the expression of hexokinase2, pyruvate kinase muscle 2, and lactate dehydrogenase A and that NCF could also weaken the concentration of lactate. However, pyruvate kinase muscle 2 activator (GC69716) and lactate addition could promote osteoclastogenesis and bone resorption and promote the expression of c-Fos and nuclear factor of activated T cells c1. Besides, NCF could also inhibit the production of ROS. In conclusion, NCF might inhibit osteoclast formation through inhibiting glycolysis metabolism and ROS production.

The effect of the Hippocampus erectus decoction on improving osteoporosis in zebrafish

The seahorse is a traditional Chinese herbal medicine that has been utilized for the treatment of conditions such as osteoporosis, nonunion fractures, knee osteoarthritis, and herniated lumbar disks.Zebrafish is an excellent animal model to study the effects of herbal preparations on osteogenesis and bone metabolism, and bone biology is highly similar to that of mammals, so it has been used to develop multiple glucocorticoid-induced osteoporosis (GIOP) models. Our study aimed to explore whether the decoction of Hippocampus erectus (DHe) administered in zebrafish larvae promotes bone health under physiological and osteoporotic conditions. In zebrafish larvae, 25 µM prednisolone solution was successfully used to induce the zebrafish osteoporosis model, which can significantly inhibit the mineralization area and degree of bone mineralization, reduce the activity of alkaline phosphatase, and increase tartrate-resistant acid phosphatase activity. The results showed that 0.3 g/L DHe had a significant improvement effect on osteoporosis in zebrafish by enhancing the mineralization degree and phosphatase activity of zebrafish, while also promoting the expression of genes associated with bone development. It can be considered a good candidate to develop new drugs against osteoporosis.

Histopathological characterization of mandibular condyles in four temporomandibular joint osteoarthritis mouse models

ObjectiveTemporomandibular joint osteoarthritis (TMJOA) has been modeled in different ways with a lack of uniformity. We aimed to investigate four TMJOA mouse models and assess histopathological changes in condyles, which could assist in the selection of animal models in further TMJOA-related studies. DesignFour TMJOA mouse models were established, including unilateral hyperocclusion, discectomy, monosodium iodoacetate injection and aged model. Bilateral condyles were collected at different time points. The condylar alterations were analyzed by Micro-CT, Hematoxylin and eosin staining, Toluidine blue staining, Safranin O staining, Trap staining, immunofluorescence staining, immunohistochemistry staining and quantitative polymerase chain reaction. ResultsRadiographic and histopathological analysis indicated that all four methods could cause condylar degeneration successfully. Differences in morphologic and histologic changes were found among four models. The hyperocclusion model was time-dependent and the lesions got worse over time. Discectomy model presented obvious damage of cartilage and subchondral bone. Injected model showed severe inflammation and chondrocyte hypertrophy. The aged model was characterized by decreased of proteoglycan and osteolysis. ConclusionsThe four methods had different characteristics and applicability. The harvest time affected the degree of cartilage degradation. Hyperocclusion was suited to explore the early-stage of TMJOA. Discectomy present advantages in investigating the long-term restoration of cartilage and subchondral bone. Monosodium iodoacetate-injection was appropriate for screening the agents for inflammatory relief. The aged model more naturally facilitated discovering underlying mechanisms in primary TMJOA. Unilateral modeling methods could initiate contralateral condylar alterations. The TMJOA models should be selected based on experimental requirements and applicability of each model.

The Glucagon-Like Peptide-1 (GLP-1) Receptor Agonist Liraglutide Regulates Sirtuin-1-Mediated Neutrophil Extracellular Traps to Improve Diabetes-Induced Bone Metabolism Imbalance

Background: Diabetes mellitus (DM) is a chronic metabolic disorder that disrupts normal bone remodeling. Objectives: This study aimed to investigate how the glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide (LIR) addresses bone metabolism imbalances induced by type-II diabetes. Methods: Type-II diabetic rat models were established through a single intraperitoneal injection of streptozotocin (STZ). Blood glucose levels were measured using a blood glucose meter, and insulin levels were assessed using an assay kit. Bone formation markers [alkaline phosphatase (ALP), osteocalcin (OCN), and procollagen I N-terminal propeptide (PINP)] and bone resorption markers [tartrate-resistant acid phosphatase (TRACP) and CTX-1] were monitored using assay kits. Bone marrow mesenchymal stem cells (BMSCs) were cultured in vitro under high-fat and high-glucose (HFHS) conditions to mimic diabetic bone metabolism dysregulation. Neutrophil extracellular traps (NETs) formation was examined through immunofluorescent staining and Western blot analysis. Results: Liraglutide was found to reduce STZ-induced NETs formation, as indicated by decreased expression of cit-H3 by 36.90% - 53.57%, myeloperoxidase (MPO) by 55.81% - 65.12%, NE by 53.95% - 65.17%, and PAD4 by 46.81% - 63.83%, alongside increased Sirtuin-1 (SIRT1) expression in femur tissue (70.71% - 91.19%). In vitro, LIR enhanced osteogenesis and inhibited apoptosis, effects that were partially reversed by SIRT1 knockdown. Additionally, SIRT1 knockdown partially restored LIR-induced reductions in oxidative stress, inflammation, and NETs formation. Conclusions: LIR mitigates diabetes-induced bone metabolism imbalance by inhibiting NETs formation through SIRT1 mediation.

Pilot study of the effect of surgical menopause on bone mineral density and quality in patients with gynecological malignancies.

To investigate the effects of surgical menopause on bone mineral density and bone quality because bilateral salpingo-oophorectomy for the treatment of gynecological malignancies is common even in premenopausal patients. This study is prospective one of bone mineral density and quality measurements after surgery for perimenopausal gynecologic malignancies. In 50 women who underwent surgical menopause for a diagnosis of gynecological malignancies, bone mineral density (BMD), blood levels of tartrate-resistant acid phosphatase 5b (TRACP-5b) and bone-specific alkaline phosphatase (BAP) as bone metabolism markers, and urinary pentosidine level as bone quality marker were measured before surgery and at multiple points up to 24 months after surgery. In a group of 22 patients who did not undergo hormone replacement therapy (HRT) (HRT- group), BMD of the lumbar spine and total hip continued to decrease significantly from 6 months postoperatively. Percentages of changes in BMD progressively increased over time after surgery. TRACP-5b and urinary pentosidine levels significantly increased 6 months postoperatively compared with preoperative levels. Comparisons between 10 patients who underwent HRT (HRT+ group) and the HRT- group revealed significant reductions in the percentage of change in lumbar spine BMD only and TRACP-5b and urinary pentosidine levels 12 months postoperatively in the former group. In this pilot study, we showed that BMD and bone-related markers are altered in patients with surgical menopause. It also suggested that HRT may reduce these influences on bone metabolism.

Abnormally accumulated GM2 ganglioside contributes to skeletal deformity in Tay-Sachs mice.

Tay-Sachs Disease is a rare lysosomal storage disorder caused by mutations in the HEXA gene, responsible for the degradation of ganglioside GM2. In addition to progressive neurodegeneration, Tay-Sachs patients display bone anomalies, including kyphosis. Tay-Sachs disease mouse model (Hexa-/-Neu3-/-) shows both neuropathological and clinical abnormalities of the infantile-onset disease phenotype. In this study, we investigated the effects of GM2 accumulation on bone remodeling activity. Here, we evaluated the bone phenotype of 5-month-old Hexa-/-Neu3-/- mice with age-matched control groups using gene expression analysis, bone plasma biomarker analysis, and micro-computed tomography. We demonstrated lower plasma alkaline phosphatase activity and calcium levels with increased tartrate-resistant acid phosphatase levels, indicating reduced bone remodeling activity in mice. Consistently, gene expression analysis confirmed osteoblast reduction and osteoclast induction in the femur of mice. Micro-computed tomography and analysis show reduced trabecular bone volume, mineral density, number, and thickness in Hexa-/-Neu3-/- mice. In conclusion, we demonstrated that abnormal GM2 ganglioside accumulation significantly triggers skeletal abnormality in Tay-Sachs mice. We suggest that further investigation of the molecular basis of bone structure anomalies is necessary to elucidate new therapeutic targets that preventthe progression ofbone symptoms and improve the life standards of Tay-Sachs patients. KEY MESSAGES: We detected the markers of bone loss-associated disorders such as osteopenia and osteoporosis in the Tay-Sachs disease mice model Hexa-/-Neu3-/-. We also demonstrated for the first time there is an increase in trabecular spacing and a reduction in trabecular thickness and number indicating skeletal abnormalities in mice model using micro-CT analysis.