The prevention effect of pulsed electromagnetic fields treatment on senile osteoporosis in vivo via improving the inflammatory bone microenvironment.

This study aimed to assess PEMF in a rat model of senile osteoporosis and its relationship with NLRP3-mediated low-grade inflammation in the bone marrow microenvironment. A total of 24 Sprague Dawley (SD) rats were included in this study. Sixteen of them were 24-month natural-aged male SD rats, which were randomly distributed into the Aged group and the PEMF group (n = 8 per group). The remaining 8 3-month -old rats were used as the Young positive control group (n = 8). Rats in the PEMF group received 12 weeks of PEMF with 40 min/day, five days per week, while the other rats received placebo PEMF intervention. Bone mineral density/microarchitecture, serum levels of CTX-1 and P1CP, and NLRP3-related signaling genes and proteins in rat bone marrow were then analyzed. The 12-week of PEMF showed significant mitigation of aging-induced bone loss and bone microarchitecture deterioration, i.e. PEMF increased the bone mineral density of the proximal femur and L5 vertebral body and improved parameters of the proximal tibia and L4 vertebral body. Further analysis showed that PEMF reversed aging-induced bone turnover, specifically, decreased serum CTX-1 and elevated serum P1CP. Furthermore, PEMF also dramatically inhibited NLRP3-mediated low-grade inflammation in the bone marrow, i.e. PEMF inhibited the levels of NLRP3, proCaspase1, cleaved Caspase1, IL-1ß, and GSDMD-N. The study demonstrated that PEMF could mitigate the aging-induced bone loss and reverses the deterioration of bone microarchitecture probably through inhibiting NLRP3-mediated low-grade chronic inflammation to improve the inflammatory bone microenvironment in aged rats.

Glucagon-Like Peptide-2 Ameliorates Age-Associated Bone Loss and Gut Barrier Dysfunction in Senescence-Accelerated Mouse Prone 6 Mice.

INTRODUCTION: Senile osteoporosis is one of the most common age-related diseases worldwide. Glucagon like peptide-2 (GLP-2), a naturally occurring gastrointestinal peptide, possesses therapeutic effects on bone loss in postmenopausal women and ovariectomized rats. However, the role of GLP-2 in senile osteoporosis and underlying mechanisms has not been explored. METHODS: GLP-2 was subcutaneously injected into the 6-month-old male senile osteoporosis model of senescence-accelerated mouse prone 6 (SAMP6) mice for 6 weeks. SAMP6 subjected to normal saline and senescence-accelerated mouse resistant 1 served as control groups. Micro-computed tomography was performed to evaluate the bone mass and microarchitecture of the mice. Osteoblastic and osteoclastic activities were determined by biochemical, quantitative real-time PCR, histological, and histomorphometric analyses combined with hematoxylin-eosin, toluidine blue, and tartrate-resistant acid phosphatase staining. We also examined the proteins and structure of intestinal tight junction using immunohistochemical assay as well as a transmission electron microscope. Serum inflammation marker levels were measured using ELISA. Additionally, anti-oxidative enzymes GPX-4 and SOD-2 and receptors of GLP-2 and vitamin D expression in the ileum and colon were detected under immunofluorescence staining. RESULTS: Six-week GLP-2 treatment attenuated bone loss in SAMP6 mice, as evidenced by increased bone mineral density, improved microarchitecture in femora, and enhanced osteogenic activities. In contrast, the activity of osteoclastic activity was not obviously inhibited. Moreover, GLP-2 ameliorated tight junction structure and protein expression in the intestinal barrier, which was accompanied by the reduction of TNF-α level. The expression of receptors of intestinal GLP-2 and vitamin D in the ileum was elevated. Furthermore, the oxidative stress in the intestines was improved by increasing the GPX-4 and SOD-2 signaling. CONCLUSION: Our findings suggest that GLP-2 could ameliorate age-associated bone loss, tight junction structure, and improved antioxidant enzyme activity in the gut in SAMP6 mice. Amelioration of gut barrier dysfunction may potentially contribute to improving bone formation and provide evidence for targeting the entero-bone axis in the treatment of senile osteoporosis.

Correlation analysis between morphologic characteristics of the thoracolumbar basivertebral foramen and Kummell's disease in patients with osteoporosis using imaging techniques.

BACKGROUND: The aging of the population is a social problem faced by many countries in the world. With the increase in the elderly population, the number of patients with Kummell's disease is also gradually increasing. No study has demonstrated that Kummell's disease has a clear correlation with the foramen of a vertebrobasilar vein. OBJECTIVES: The research was conducted to describe and evaluate the morphological characteristics of a basivertebral foramen in patients with osteoporosis and Kummell's disease by CT; to infer whether the specific morphological characteristics of basivertebral foramen may be one of the risk factors of Kummell's disease; to provide clinical suggestions for the treatment of Kummell's disease. DESIGN: Retrospective analysis from January 2020 to December 2021 on 83 patients with 83 vertebral bodies (T8-L5) diagnosed with senile osteoporosis and Kummell's disease hospitalized in our hospital due to chronic low back pain, including 57 women and 23 men. Group A was assigned for the following patients: the age ranged from 59 to 86 years old, with the average age of 67.30 ± 7.32 years old; the body mass index ranged from 20.01 to 29.46 kg/m2, with the average body mass index of 23.51 ± 3.03 kg/m2.Group B was assigned for the following patients: 83 patients diagnosed with senile osteoporosis in our outpatient department from January 2020 to December 2021, including 41 males and 42 females; the age ranged from 60 to 85 years, with an average age of 68.52 ± 4.68 years old; the height to weight ratio met the normal reference standard (except 20% above or 10% below the standard weight). Through the lanwon PACS imaging system, the related parameters of the vertebrobasilar foramen in patients with osteoporosis and Kummell's disease were measured to evaluate and analyze the correlation between the morphological characteristics of the vertebrobasilar foramen in patients with osteoporosis and Kummell's disease. RESULTS: In patients with osteoporosis, the distribution of incidence rate of Kummell's disease in the spine was consistent with that of osteoporotic compression fractures. Sagittal view of the vertebral body on CT scan and the triangular-shaped, trapezoidal-shaped, and irregular-shaped basivertebral foramen in group A accounted for 18%,57%,and 36%,respectively. In group B, triangular-shaped, trapezoidal-shaped, and irregular-shaped foramen accounted for 51%,17%,and 26%,respectively.The distribution of triangular-shaped, trapezoidal-shaped, and irregular-shaped foramen was compared between groups A and B, and the difference was recorded as statistically significant (P < 0.05). Additionally, the difference in the distribution of triangular-shaped, trapezoidal-shaped, and irregular-shaped foramen in group A was found statistically significant (P < 0.05),while that of Group B was found statistically insignificant (P > 0.05).On a horizontal CT scan of the vertebra of group A, triangles, trapezoids, and irregularities accounted for 28%, 26%, and 47%, respectively. In group B, triangles,trapezoids,and irregularities accounted for 31%, 37%, and 30%, respectively. The difference in the distribution of the triangular-shaped and trapezoidal-shaped foramen in groups A and B was statistically insignificant (P > 0.05), while that of irregular-shaped was statistically significant (P < 0.05). Additionally, there was no statistical significance (P > 0.05) in the difference in the morphological distribution of triangular-shaped and trapezoidal-shaped foramen in group A, while that of irregular-shaped was found to be statistically significant (P < 0.05). Further, the difference in the morphological distribution of triangular-shaped, trapezoidal-shaped, and irregular-shaped foramen in group B was not statistically significant (P > 0.05).In general, about 8% of the vertebral body of BF has an osseous septum. In group A, 97% are single-holed while the remaining 3% are porous; in group B, those with single holes accounted for 76%, while the remaining 24% are porous. In groups A and B, the difference in the morphological distribution of single-holed and multi-holed T8, T11, T12, L1, L2, L4, and L5 vertebral bodies was statistically significant (P < 0.05). In group A, the difference in the distribution of single-holed and multi-holed L1 and L5 vertebral bodies was statistically significant (P < 0.05). Similarly, the difference in the distribution of single-holed and multi-holed T8, T11, T12, L1, L2, and L4 basivertebral foramen was statistically significant (P < 0.05). CONCLUSIONS: In patients with osteoporosis, the incidence of vertebral Kummell's disease can be associated with the morphological characteristics of the basivertebral foramen, as observed in the CT scan. Furthermore, the vertebral body with trapezoidal-shaped and irregular-shaped basivertebral foramen and boneless septum in the foramen is highly susceptible to Kummell's disease.

Ten existing osteoporosis prediction tools for the successful application of National Health Insurance-reimbursed anti-osteoporosis medications in long-term care residents in Taiwan.

BACKGROUND/PURPOSE: Osteoporotic fracture introduce enormous societal and economic burden, especially for long-term care residents (LTCRs). Although osteoporosis prevention for LTCRs is urgently needed, obstacles such as frail status and inconvenient hospital visits hurdled them from necessary examinations and diagnoses. We aimed to test 10 existing osteoporosis screening tools (OSTs), which can be easily used in institutions and serve as a prediction, for accurately determining the outcome of a Taiwan's National Health Insurance (NHI)-reimbursed anti-osteoporosis medications (AOMs) application for LTCRs. METHODS: This prospective analysis recruited 444 patients from LTC institutions between October 2018 and November 2019. Predictions of whether the NHI-reimbursed AOMs criteria was met were tested for 10 OSTs. The results of OSTs categorized into self-reported or validated based on previous fracture history were self-reported by LTCRs or validated by imaging data and medical records, respectively. The receiver operating characteristic curve and the optimal cut-off points for LTCRs based on Youden's index were explored. RESULTS: Overall, the validated OSTs had a higher positive predictive value (PPV) and negative predictive value (NPV) summation than the corresponding reported OSTs. The validated FRAX-Major was the best OST (PPV = 63.6%, NPV = 82.4% for the male group and, PPV = 78.8%, NPV = 90.0% for the female group). After applying the optimum cut-off derived from Youden's index, the validated FRAX-Major (PPV = 75.4%, NPV = 92.0%)) remained performed best for men. In female population, validated FRAX-Major (PPV = 87.2%, NPV = 84.1%) and validated osteoporosis prescreening risk assessment (OPERA; PPV = 96.1%, NPV = 79.7%)) both provided good prediction results. CONCLUSION: FRAX-Major and OPERA have better prediction ability for LTCRs to acquire NHI-reimbursed AOMs. The validated fracture history and adjusted cut-off points could prominently increase the PPV during prediction.

Does the association of therapeutic exercise and supplementation with sucrosomial magnesium improve posture and balance and prevent the risk of new falls?

BACKGROUND: Fracture of the proximal femur is the most feared complication of osteoporosis. Given the numerous physiological functions that magnesium performs in our body, in the literature there is a correlation between osteoporosis and low serum levels of magnesium. AIM: Evaluate the incidence of hypomagnesemia in patients with lateral fragility fracture of the proximal femur, the possible correlation between serum magnesium levels and fractures, and the effectiveness of supplementing Sucrosomial® magnesium associated with therapeutic exercise on the outcome of these patients. METHODS: We divided the study into two parts. In the first part, we assessed the preoperative incidence of hypomagnesemia in patients using a blood test. In the second part, patients with hypomagnesemia were divided, in the post-operative period, into two groups, who received, respectively, only therapeutic exercise or oral supplementation with sucrosomial magnesium associated with therapeutic exercise. RESULTS: Half of the patients with fragility femoral fracture had hypomagnesemia, with a higher incidence of the subclinical form. From the comparison between the two groups, the T1 treatment group showed a significant improvement in blood levels of magnesium (2.11 ± 0.15 vs. 1.94 ± 0.11; p < 0.05), on the NRS scale (5.7 ± 0.81 vs. 6.6 ± 1.18; p < 0.05), the Tinetti scale (17.3 ± 1.15 vs. 15.2 ± 2.98; p < 0.05) and the SarQoL questionnaire (47.3 ± 5.21 vs. 44.9 ± 5.54; p < 0.05). CONCLUSIONS: More attention would be needed in the diagnosis and correction of subclinical hypomagnesemia and not just the simple and clinically evident one, including hypomagnesemia among the modifiable risk factors for osteoporosis.

Bone marrow stromal cells (BMSCs CD45- /CD44+ /CD73+ /CD90+ ) isolated from osteoporotic mice SAM/P6 as a novel model for osteoporosis investigation.

Available therapies aimed at treating age-related osteoporosis are still insufficient. Therefore, designing reliable in vitro model for the analysis of molecular mechanisms underlying senile osteoporosis is highly required. We have isolated and characterized progenitor cells isolated from bone marrow (BMSCs) of osteoporotic mice strain SAM/P6 (BMSCSAM/P6 ). The cytophysiology of BMSCSAM/P6 was for the first time compared with BMSCs isolated from healthy BALB/c mice (BMSCBALB/c ). Characterization of the cells included evaluation of their multipotency, morphology and determination of specific phenotype. Viability of BMSCs cultures was determined in reference to apoptosis profile, metabolic activity, oxidative stress, mitochondrial membrane potential and caspase activation. Additionally, expression of relevant biomarkers was determined with RT-qPCR. Obtained results indicated that BMSCSAM/P6 and BMSCBALB/c show the typical phenotype of mesenchymal stromal cells (CD44+, CD73+, CD90+) and do not express CD45. Further, BMSCSAM/P6 were characterized by deteriorated multipotency, decreased metabolic activity and increased apoptosis occurrence, accompanied by elevated oxidative stress and mitochondria depolarisation. The transcriptome analyses showed that BMSCSAM/P6 are distinguished by lowered expression of molecules crucial for proper osteogenesis, including Coll-1, Opg and Opn. However, the expression of Trap, DANCR1 and miR-124-3p was significantly up-regulated. Obtained results show that BMSCSAM/P6 present features of progenitor cells with disturbed metabolism and could serve as appropriate model for in vitro investigation of age-dependent osteoporosis.

Metabolomic analysis to elucidate the change of the n-3 polyunsaturated fatty acids in senescent osteoblasts.

Senile osteoporosis is a major public health concern, and yet, effective treatment methods do not exist. Herein, we used metabolomics to analyze the change of n-3 polyunsaturated fatty acids (PUFA) in senescent osteoblasts. We found that with an increase in the number of passages, the osteoblasts proliferative ability, alkaline phosphatase activity, and expression levels of bone metabolism genes decreased, the expression levels of aging-related genes increased, the damage caused by oxidative stress became more severe. Furthermore, levels of n-3 PUFA family members were downregulated in passage 10 than in passage 3 osteoblasts. These findings indicated that multiple passages led to more severe oxidative stress damage in senescent osteoblasts, which could be related to a decrease in n-3 PUFA levels. We believe that unsaturated fatty acid metabolism is a key factor involved in osteoblast senescence and that a proper dietary intake of n-3 PUFA may delay the occurrence senile osteoporosis.

The old sheep: a convenient and suitable model for senile osteopenia.

INTRODUCTION: Existing osteoporosis models in sheep exhibit some disadvantages, e.g., challenging surgical procedures, serious ethical concerns, failure of reliable induction of substantial bone loss, or lack of comparability to the human condition. This study aimed to compare bone morphological and mechanical properties of old and young sheep, and to evaluate the suitability of the old sheep as a model for senile osteopenia. MATERIALS AND METHODS: The lumbar vertebral body L3 of female merino sheep with two age ranges, i.e., old animals (6-10 years; n = 41) and young animals (2-4 years; n = 40), was analyzed concerning its morphological and mechanical properties by bone densitometry, quantitative histomorphometry, and biomechanical testing of the corticalis and/or central spongious region. RESULTS: In comparison with young sheep, old animals showed only marginally diminished bone mineral density of the vertebral bodies, but significantly decreased structural (bone volume, - 15.1%; ventral cortical thickness, - 11.8%; lateral cortical thickness, - 12.2%) and bone formation parameters (osteoid volume, osteoid surface, osteoid thickness, osteoblast surface, all - 100.0%), as well as significantly increased bone erosion (eroded surface, osteoclast surface). This resulted in numerically decreased biomechanical properties (compressive strength; - 6.4%). CONCLUSION: Old sheep may represent a suitable model of senile osteopenia with markedly diminished bone structure and formation, and substantially augmented bone erosion. The underlying physiological aging concept reduces challenging surgical procedures and ethical concerns and, due to complex alteration of different facets of bone turnover, may be well representative of the human condition.

Senile Osteoporosis: The Involvement of Differentiation and Senescence of Bone Marrow Stromal Cells.

Senile osteoporosis has become a worldwide bone disease with the aging of the world population. It increases the risk of bone fracture and seriously affects human health. Unlike postmenopausal osteoporosis which is linked to menopause in women, senile osteoporosis is due to aging, hence, affecting both men and women. It is commonly found in people with more than their 70s. Evidence has shown that with age increase, bone marrow stromal cells (BMSCs) differentiate into more adipocytes rather than osteoblasts and undergo senescence, which leads to decreased bone formation and contributes to senile osteoporosis. Therefore, it is necessary to uncover the molecular mechanisms underlying the functional changes of BMSCs. It will benefit not only for understanding the senile osteoporosis development, but also for finding new therapies to treat senile osteoporosis. Here, we review the recent advances of the functional alterations of BMSCs and the related mechanisms during senile osteoporosis development. Moreover, the treatment of senile osteoporosis by aiming at BMSCs is introduced.

Clinical effect of Zoledronic Acid in the treatment of Senile Osteoporosis.

OBJECTIVE: To investigate the clinical efficacy of zoledronic acid in the treatment of senile osteoporosis. METHODS: One hundred and six cases of senile osteoporosis who visited to our hospital from August 2017 to December 2018 for treatment were selected and randomly divided into a control group and an observation group. The control group was treated with conventional therapy, while the observation group was treated with zoledronic acid in addition to the treatment of the control group. Bone mineral density, pain degree, therapeutic effect and adverse reactions of the two groups were compared. RESULTS: The total effective rate of the observation group was 96.67%, higher than 80.00% of the control group (P<0.05); the bone mineral density of lumbar vertebrae, femoral neck and Ward' area in the two groups increased after 6 months of treatment, and the bone mineral density of the observation group increased more than that of the control group (P<0.05); the pain degree of the observation group was lower than that of the control group after 6 months of treatment, and the difference was significant (P<0.05). There was no significant difference in the occurrence of adverse reactions between the two groups (P>0.05). CONCLUSION: Zoledronic acid is helpful to alleviate clinical symptoms, reduce the degree of bone pain, and promote the increase of bone mass, and has high safety in the treatment of senile osteoporosis, which is worth promotion.

Exendin-4 enhances proliferation of senescent osteoblasts through activation of the IGF-1/IGF-1R signaling pathway.

A growing body of evidence indicates that treatment with glucagon-like peptide-1 (GLP-1) receptor agonists can be beneficial for patients with osteoporosis. However, the underlying mechanism by which GLP-1 receptor agonists improve osteoporosis remains unclear. In this study, we assessed the anti-osteoporosis effects of Exendin-4, a highly potent GLP-1 receptor agonist, using a rat senescent osteoblast model. We found that Exendin-4 improved proliferation of senescent osteoblasts, as indicated by MTT assay and ALP activity detection. RT-qPCR revealed that Exendin-4 up-regulated the expression of bone metabolism genes (OPG, RANKL, BGP) and down-regulated the expression of aging-related genes (p16, p21, p53). Meanwhile, we observed a sustained increase in IGF-1 receptor (IGF-1R) expression, and not GLP-1 receptor (GLP-1R) expression, in senescent osteoblasts treated with Exendin-4. Furthermore, intervention with Exendin-4 in senescent osteoblasts increased IGF-1, p-PI3K, and p-Akt protein levels, as shown by western blot analysis. Finally, downregulation of IGF-1 by RNAi inhibited the anti-osteoporosis effects of Exendin-4, which is associated with the IGF-1/PI3K/Akt signaling pathway. In summary, these results indicate that the GLP-1 receptor agonist Exendin-4 promotes proliferation of senescent osteoblasts by up-regulating IGF-1R expression and activating the IGF-1/PI3K/Akt signaling pathway, thereby preventing senile osteoporosis.

Effects of Osteoglycin (OGN) on treating senile osteoporosis by regulating MSCs.

BACKGROUND: Significant amount of bone mass is lost during the process of aging due to an imbalance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption in bone marrow microenvironment, which leads to net bone loss in the aging population, resulting in the pathogenesis of osteoporosis. METHODS: Firstly, differences in proliferative capacity of adipocyte or adipogenic differentiation in mouse mesenchymal stem cells (MMSCs) and senile mouse model-derived bone marrow mesenchymal stem cells (SMMSCs), as well as mRNA expression of OGN and PPARγ2 were observed. Secondly, osteogenic abilities of MMSCs and SMMSCs treated with rosiglitazone (a PPARγ2 agonist) to induce osteogenic changes were observed, and negative correlation of PPARγ2 with OGN was evaluated. Thirdly, the role of SMMSCs in promoting osteogenesis was examined through enhancing expression of OGN; besides, the related mechanism was investigated by means of expression of related adipocyte and osteoblast specific genes. RESULTS: Forced OGN expression by OGN-infected lentivirus could increase expression of Wnt5b, RUNX2, OCN, ALP and Colla1, as well as bone formation, while decreases expression of adipogenesis marker PPARγ2. It resulted in expression inhibition of adipocyte genes such as adipocytic differentiation related genes adipocyte binding protein 2 (aP2) and osteoclast differentiation factor Rankl in bone marrow, giving rise to increased bone mass. CONCLUSION: OGN may plays a significant role in osteoporosis, which may also provide a potential target for therapeutic intervention of senile osteoporosis characterized by altered differentiation of BMSCs into osteoblasts and adipocytes.

Transpedical Interbody Bone Grafting in the Treatment of Senile Osteoporotic Vertebral Fracture.

OBJECTIVE: To evaluate the clinical effect of transpedical interbody bone grafting in the treatment of senile osteoporotic vertebral fracture. METHODS: Eighty-six elders with osteoporotic vertebral fracture were selected and divided into a control group and a test group using random double-blind method. Patients in the control group were treated by short-segment transpedicular screw system internal fixation, while patients in the test group were treated by short-segment transpedicular screw system internal fixation in combination with transpedical interbody bone grafting. Operation related indexes and fracture recovery condition were compared between the two groups. RESULTS: The overall effective rate of the test group was 93.02%, much higher than the control group (76.74%) (P<0.05). The difference of operation duration, intraoperative bleeding volume, length of hospital stay, fracture healing time, preoperative vertebral height loss and preoperative Cobb's angle between the two groups had no statistical significance (P>0.05). The postoperative pain score of the test group was lower than that of the control group, and the difference was statistically significant (P<0.05). The vertebral height loss and Cobb's angle of the test group were superior to those of the control group at the last follow up, and the difference had statistical significance (P<0.05). The incidence of internal fixator loosening of the test group was much lower than that of the control group (P<0.05). CONCLUSION: Short-segment transpedicular screw system internal fixation in combination with transpedical interbody bone grafting shows favorable effects in the treatment senile osteoporotic vertebral fracture, resulting in mild pain and less loss of vertebral height and angle; hence it is worth promotion in clinic.

Positive effect of peptide-calcium chelates from Grifola frondosa on a mouse model of senile osteoporosis.

Calcium supplementation has been shown to be efficacious in mitigating the progression of senile osteoporosis (SOP) and reducing the incidence of osteoporotic fractures resulting from prolonged calcium shortage. In this study, Grifola frondosa (GF) peptides-calcium chelate were synthesized through the interaction between peptide from GF and CaCl2. The chelation reaction was shown to involve the participation of the amino and carboxyl groups in the peptide, as revealed by scanning electron microscope, Fourier-transform infrared, and ultraviolet spectrophotometry. Furthermore, a mouse model of (SOP) induced by d-galactose was established (SCXK-2018-0004). Results demonstrated that low dosage of low-molecular weight GF peptides-calcium chelates (LLgps-Ca) could significantly improve serum index and pathological features of bone tissue and reduce bone injury. Further research suggested that LLgps-Ca could ameliorate SOP by modulating the disrupted metabolic pathway, which includes focal adhesion, extracellular matrix receptor interaction, and PI3K-Akt signaling pathway. Using Western blot, the differentially expressed proteins were further confirmed. Thus, calciumchelating peptides from GF could serve as functional calcium agents to alleviate SOP.

Elimination of Senescent Osteocytes by Bone-Targeting Delivery of ß-Galactose-Modified Maytansinoid Prevents Age-Related Bone Loss.

The accumulation of senescent cells in bone during aging contributes to senile osteoporosis, and clearance of senescent cells by senolytics could effectively alleviate bone loss. However, the applications of senolytics are limited due to their potential toxicities. Herein, small extracellular vesicles (sEVs) have been modified by incorporating bone-targeting peptide, specifically (AspSerSer)6, to encapsulate galactose-modified Maytansinoids (DM1). These modified vesicles are referred to as (AspSerSer)6-sEVs/DM1-Gal, and they have been designed to specifically clear the senescent osteocytes in bone tissue. In addition, the elevated activity of lysosomal ß-galactosidase in senescent osteocytes, but not normal cells in bone tissue, could break down DM1-Gal to release free DM1 for selective elimination of senescent osteocytes. Mechanically, DM1 could disrupt tubulin polymerization, subsequently inducing senescent osteocytes apoptosis. Further, administration of bone-targeting senolytics to aged mice could alleviate aged-related bone loss without non-obvious toxicity. Overall, this bone-targeting senolytics could act as a novel candidate for specific clearance of senescent osteocytes, ameliorating age-related bone loss, with a promising therapeutic potential for senile osteoporosis.

Zhuang-Gu-Fang promotes osteoblast differentiation via myoblasts and myoblast-derived exosomal miRNAs:miR-5100, miR-126a-3p, miR-450b-5p, and miR-669a-5p.

BACKGROUND: Senile osteoporosis (SOP) is an age-related systemic metabolic bone disorder. Previous studies have proved that Zhuang-Gu-Fang (ZGF) modulates myokines, stimulates osteogenic differentiation, and mitigates osteoporosis. OBJECTIVE: To elucidate the mechanism by which ZGF promotes osteogenic differentiation via myoblast and myoblast exosomal microRNAs (miRNAs) and investigate its potential implications in senile osteoporosis. METHODS: Characterization of ZGF and ZGF serum using UHPLC-MS/MS. An alkaline phosphatase (ALP) activity assay and staining techniques were employed to corroborate the impacts of ZGF on the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) via myoblasts. Subsequently, exosomes derived from myoblasts were isolated through ultracentrifugation. The effects of ZGF on the BMSCs' osteogenic differentiation were substantiated through ALP activity, alizarin red staining, and a quantitative real-time polymerase reaction system (qRT-PCR). Selected miRNAs were identified via high-throughput sequencing and subjected to differential expression analysis, and subsequently validated through qRT-PCR. The senescence-accelerated (SAMP6) mice were selected as the SOP models. qRT-PCR analyses were further conducted to confirm the expression levels of these selected miRNAs in the muscle and bone tissues of the SAMP6 mice, and the protein expression of osteogenesis-related transcription factors OCN and Osterix in its bone tissue was evaluated by immunofluorescence staining analysis (IF). RESULTS: ZGF may enhance the osteogenic differentiation of BMSCs through myoblasts and myoblast-derived exosomes. High-throughput sequencing, differential expression analysis, and subsequent qRT-PCR validation identified four miRNAs that stood out due to their significant differential expression: miR-5100, miR-142a-3p, miR-126a-3p, miR-450b-5p and miR-669a-5p. Moreover, the mice experiment corroborated these findings, which revealed that ZGF not only up-regulated the expression of miR-5100, miR-450b-5p and miR-126a-3p in muscle and bone tissues but also concurrently down-regulated the expression of miR-669a-5p in these tissues. IF staining analysis indicated that ZGF can significantly increase the protein expression of the osteogenic transcription factors OCN and Osterix in the bone tissue of mice with SOP. CONCLUSIONS: ZGF can promote osteogenic differentiation of osteoblasts, regulate bone metabolism, and thereby delay the process of SOP. Perhaps, its mechanism is to upregulate myoblast-derived exosomes miR-5100, miR-126a-3p, and miR-450b-5p or downregulate miR-669a-5p. This study reports for the first time that myoblast exosomes miR-669a-5p and miR-450b-5p are novel targets for the regulation of osteoblastic differentiation and the treatment of SOP.

Radial extracorporeal shockwave promotes osteogenesis-angiogenesis coupling of bone marrow stromal cells from senile osteoporosis via activating the Piezo1/CaMKII/CREB axis.

Radial extracorporeal shockwave (r-ESW) and bone marrow stromal cells (BMSCs) have been reported to alleviate senile osteoporosis (SOP), but its regulatory mechanism remains unclear. In this study, we firstly isolated human BMSCs from bone marrow samples and treated with varying r-ESW doses. And we found that r-ESW could enhance the proliferation of SOP-BMSCs in a dose-dependent manner by EdU assay. Subsequently, the impact of r-ESW on the proliferation, apoptosis and multipotency of BMSCs was assessed. And the outcomes of flow cytometry, Alizarin red S (ARS), and tube formation test demonstrated that the optimal shockwave obviously boosted SOP-BMSCs osteogenesis and angiogenesis but exhibited no significant impact on cell apoptosis. Additionally, the signaling of Piezo1 and CaMKII/CREB was examined by Western blotting, qPCR and immunofluorescence. And the results showed that r-ESW promoted the expression of Piezo1, increased intracellular Ca2+ and activated the CaMKII/CREB signaling pathway. Then, the application of Piezo1 siRNA hindered the r-ESW-induced enhancement ability of osteogenesis coupling with angiogenesis of SOP-BMSCs. The use of the CaMKII/CREB signaling pathway inhibitor KN93 suppressed the Piezo1-induced increase in osteogenesis and angiogenesis in SOP-BMSCs. Finally, we also found that r-ESW might alleviate SOP in the senescence-accelerated mouse prone 6 (SAMP6) model by activating Piezo1. In conclusion, our research offers experimental evidence and an elucidated underlying molecular mechanism to support the use of r-ESW as a credible rehabilitative treatment for senile osteoporosis.

Identification of PKM2 as a pyroptosis-related key gene aggravates senile osteoporosis via the NLRP3/Caspase-1/GSDMD signaling pathway.

BACKGROUNDS: Senile osteoporosis-alternatively labeled as skeletal aging-encompasses age-induced bone deterioration and loss of bone microarchitecture. Recent studies have indicated a potential association between senile osteoporosis and chronic systemic inflammation, and pyroptosis in bone marrow-derived mesenchymal stem cells is speculated to contribute to bone loss and osteoporosis. Therefore, targeting pyroptosis in stem cells may be a potential therapeutic strategy for treating osteoporosis. METHODS: Initially, we conducted bioinformatics analysis to screen the GEO databases to identify the key gene associated with pyroptosis in senile osteoporosis. Next, we analyzed the relationship between altered proteins and clinical data. In vitro experiments were then performed to explore whether the downregulation of PKM2 expression could inhibit pyroptosis. Additionally, an aging-related mouse model of osteoporosis was established to validate the efficacy of a PKM2 inhibitor in alleviating osteoporosis progression. RESULTS: We identified PKM2 as a key gene implicated in pyroptosis in senile osteoporosis patients through bioinformatics analysis. Further analyses of bone marrow and stem cells demonstrated significant PKM2 overexpression in senile osteoporosis patients. Silencing PKM2 expression inhibited pyroptosis in senile stem cells, of which the osteogenesis potential and angiogenic function were also primarily promoted. Moreover, the results in vivo demonstrated that administering PKM2 inhibitors suppressed pyroptosis in senile osteoporosis mice and mitigated senile osteoporosis progression. CONCLUSION: Our study uncovered PKM2, a key pyroptosis marker of bone marrow mesenchymal stem cells in senile osteoporosis. Shikonin, a PKM2 inhibitor, was then identified as a potential drug candidate for the treatment of osteoporosis.

Effects of the combination of Epimedii Folium and Ligustri Lucidi Fructus on apoptosis and autophagy in SOP rats and osteoblasts via PI3K/AKT/mTOR pathway.

BACKGROUND: This study aimed to investigate the effects of the combination of Epimedii Folium (EF) and Ligustri Lucidi Fructus (LLF) on regulating apoptosis and autophagy in senile osteoporosis (SOP) rats. METHODS: Firstly, we identified the components in the decoction and drug-containing serum of EL (EF&LLF) by Ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS). Secondly, SOP rats were treated with EF, LLF, EL and caltrate to evaluate the advantages of EL. Finally, H2O2-, chloroquine-, and MHY1485-induced osteoblasts were treated with different doses of EL to reveal the molecular mechanism of EL. We detected bone microstructure, oxidative stress levels, ALP activity and the expressions of Bax, Bcl-2, caspase3, P53, Beclin-1, p-PI3K, PI3K, p-Akt, Akt, p-mTOR, mTOR, and LC3 in vivo and in vitro. RESULTS: 36 compounds in EL decoction and 23 in EL-containing serum were identified, including flavonoids, iridoid terpenoids, phenylethanoid glycosides, polyols and triterpenoids. EL could inhibit apoptosis activity and increase ALP activity. In SOP rats and chloroquine-inhibited osteoblasts, EL could improve bone tissue microstructure and osteoblasts functions by upregulating Bcl-2, Beclin1, and LC3-II/LC3-I, while downregulating p53 in all treatment groups. In H2O2-induced osteoblasts, EL could upregulate the protein and mRNA expressions of Bcl-2 while downregulate LC3-II/LC3-I, p53 and Beclin1. Besides, EL was able to down-regulate PI3K/AKT/mTOR pathway which activated in SOP rats and MHY1485-induced osteoblasts. CONCLUSIONS: These findings demonstrate that EL with bone protective effects on SOP rats by regulating autophagy and apoptosis via PI3K/Akt/mTOR signaling pathway, which might be an alternative medicine for the treatment of SOP.

Denosumab in elderly osteoporotic patients. A narrative review.

Objective: Denosumab, an antiresorptive agent, has shown results in improving bone mineral density and reducing fractures in postmenopausal women. While bisphosphonates are commonly used as initial therapy for osteoporosis, some studies suggest that denosumab could be an alternative initial treatment for high-risk patients, particularly the elderly population. This narrative literature review aimed to assess the use of denosumab in elderly individuals with osteoporosis, excluding its oncology applications. Method: Multiple online databases including Scopus, PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and PEDro were searched for relevant English-language trials. Results: Between about hundred identified, the review selected 21 articles full-meeting the inclusion criteria. These papers all reporting that Denosumab demonstrated significant efficacy in reducing vertebral and nonvertebral fractures in postmenopausal and senile osteoporosis. Conclusion: Even if limited evidence exists regarding its long-term effectiveness in elderly patients, nevertheless denosumab may be considered a first-line treatment for high-risk elderly patients with senile osteoporosis, particularly for those unable to take bisphosphonates. It has shown superior outcomes in improving bone density and reducing fracture risk, even in frail elderly individuals. Long-term use of denosumab has been reported as safe and effective, enhancing treatment compliance and outcomes.