Kaempferol promotes the osteogenesis in rBMSCs via mediation of SOX2/miR-124-3p/PI3K/Akt/mTOR axis

Using network pharmacology and molecular docking technology, proteomics and experiments were used to verify the effect of Yigu decoction (YGD) on the expression of key genes in osteoporotic mice

BACKGROUND

Yigu decoction (YGD) is a traditional Chinese medicine prescription for the treatment of osteoporosis, although many clinical studies have confirmed its anti-OP effect, but the specific mechanism is still not completely clear.

METHODS

In this study, through the methods of network pharmacology and molecular docking, the material basis and action target of YGD in preventing and treating OP were analyzed, and the potential target and mechanism of YGD in preventing and treating OP were clarified by TMT quantitative protein and experiment.

RESULTS

Network pharmacology and molecular docking revealed that the active components of YGD were mainly stigmasterol and flavonoids. Molecular docking mainly studied the strong binding ability of stigmasterol to the target. Animal proteomics verified the related mechanism of YGD in preventing and treating OP. Based on the KEGG enrichment of network pharmacology and histology, our animal experiments in vivo verified that YGD may play a role in the treatment of OP by mediating hif1- α/vegf/glut1 signal pathway.

CONCLUSIONS

YGD prevention and treatment of OP may be achieved by interfering with multiple targets. This study confirmed that it may promote osteoblast proliferation and protect osteoblast function by up-regulating the expression of proteins related to HIF signal pathway.

Kaempferol combats the osteogenic differentiation damage of periodontal ligament stem cells in periodontitis via regulating EphrinB2-mediated PI3K/Akt and P38 pathways

BACKGROUND

The osteogenic differentiation of periodontal ligament stem cells (PDLSCs) plays a fundamental role in endogenous bone regeneration during periodontitis treatment, yet achieving consistent differentiation under inflammatory conditions remains clinically challenging. Kaempferol, a phytochemical flavonol, has demonstrated osteoprotective efficacy in osteoporosis and bone repair models. However, whether kaempferol exerts pro-osteogenic effects on PDLSCs within the pathologically complex microenvironment of periodontitis, and through what molecular mechanisms, remains unexplored.

PURPOSE

This study aimed to systematically characterize the therapeutic efficacy of kaempferol in restoring osteogenic differentiation of human PDLSCs under inflammatory stress, and promoting bone regeneration in a mice periodontitis model, and elucidate novel molecular targets and downstream mechanisms mediating these regenerative actions.

METHODS

An in vitro inflammatory microenvironment was established using lipopolysaccharide (LPS)-stimulated human PDLSCs to mimic periodontitis-induced osteogenic impairment. Osteogenic recovery was assessed through alkaline phosphatase (ALP), alizarin red S staining, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot analysis of osteogenesis-related markers (ALP, RUNX2, OSX, OPN). The bioinformatics, network pharmacology and siRNA transfection were performed to identify EphrinB2 as kaempferol's putative cellular target. Downstream PI3K/Akt and p38 MAPK pathway activation was evaluated through phosphoprotein analysis. In vivo validation employed micro-CT quantification of alveolar bone loss and immunohistochemical profiling of pathways key proteins in a mice periodontitis model.

RESULTS

Kaempferol dose-dependently rescued LPS-impaired osteogenic differentiation in human PDLSCs, especially at 10 μM, where kaempferol significantly reversed suppressed ALP activity, mineralized nodule formation, and transcriptional and protein expression of osteogenic markers (ALP, RUNX2, OSX, OPN). Mechanistically, kaempferol upregulated the key target EphrinB2 under inflammatory stress, thereby reactivating the downstream PI3K/Akt and p38 pathways. In periodontitis mice, kaempferol administration (10 mg/kg) significantly promoted the periodontal expression of OPN and EphrinB2, restored the phosphorylation of PI3K, AKT, and P38, attenuating alveolar bone loss by 63.8 % (BV/TV: 72.4 % ± 2.07 vs. 44.2 % ± 3.19 in CON).

CONCLUSION

Kaempferol could rescue PDLSCs' osteogenic differentiation and mitigates bone loss in periodontitis microenvironments by targeting EphrinB2 to activate PI3K/Akt and P38 pathways. This work underscores kaempferol's potential as a natural therapeutic for reversing pathological bone resorption and promoting periodontal regeneration.

Kaempferol, a widely ingested dietary flavonoid and supplement, enhances biological performance via hormesis, especially for ageing-related processes

Kaempferol is a polyphenol in various fruits and vegetables. It is also commercially developed and sold to consumers as a supplement. It has been extensively assessed in clinical trials for clinical utility based upon its numerous experimentally based chemopreventive properties. Kaempferol has been evaluated at the levels of molecule, cell, and individual animal, showing a broad spectrum of biological effects. Kaempferol-induced hormetic concentration responses are common, being reported in many cell types and biological models for numerous endpoints. While the hormetic effects of kaempferol are biologically diverse, there has been a strong focus on age-related endpoints affecting numerous organ systems and endpoints, indicating that kaempferol is a senolytic agent, showing similar properties as quercetin and fisetin. This paper offers the first integrated evaluation of kaempferol-induced hormetic dose responses, their quantitative characteristics, mechanistic explanations, extrapolative strengths or limitations, and related experimental design, biomedical, therapeutic, ageing, and public health, including ageing related applications.

Bioactive Compounds from Propolis on Bone Homeostasis: A Narrative Review

This narrative review explores the potential effects of Propolis and its bioactive compounds on bone health. Propolis, a resinous product collected by bees, is renowned for its antimicrobial, anti-inflammatory, and antioxidant properties. Recent research emphasizes its positive role in osteogenesis, primarily through the modulation of osteoclast and osteoblast activity via molecular pathways. Key mechanisms include reducing inflammatory cytokines, protecting against oxidative stress, and upregulating growth factor essential for bone formation. While compounds such as Caffeic Acid Phenethyl Ester, Apigenin, Quercetin, and Ferulic Acid have been well-documented, emerging evidence points to the significant roles of less-studied compounds like Pinocembrin, Kaempferol, p-Coumaric acid, and Galangin. This review synthesizes the current literature, focusing on the mechanisms by which these bioactive compounds influence osteogenesis. Firstly, it explores the techniques for characterizing bioactive compounds presented in propolis, the chemogeographic variations in its composition, and the effects of both crude extracts and isolated compounds on bone tissue, offering a comprehensive analysis of recent findings across different experimental models. Further, it discusses the effects of Propolis compounds on bone health. In summary, these compounds modulate signaling pathways, including nuclear factor kappa beta, wingless-related integration site, mitogen-activated protein kinase, vascular endothelial growth factor, and reactive oxygen species. These pathways influence the receptor activator of nuclear factor kappa-β/receptor activator of nuclear factor kappa-β ligand/osteoprotegerin system, fostering bone cell differentiation. This regulation mitigates excessive osteoclast formation, stimulates osteoblast activity, and ultimately contributes to the restoration of bone homeostasis by maintaining a balanced bone remodeling process.

Comprehensive bioinformatics analysis reveals novel potential biomarkers associated with aging and mitochondria in osteoporosis

Osteoporosis (OP) is a prevalent age-related bone metabolic disease. Aging and mitochondrial dysfunction are involved in the onset and progression of OP, but the specific mechanisms have not been elucidated. The aim of this study was to identify novel potential biomarkers associated with aging and mitochondria in OP. In this study, based on GEO database, aging-related and mitochondria-related differentially expressed genes (AR&MRDEGs) were screened. The AR&MRDEGs were enriched in mitochondrial structure and function. Then, 6 key genes were identified by WGCNA and multiple machine learning, and a novel diagnostic model was constructed. The efficacy of diagnostic model was validated using external datasets. The results showed that diagnostic model had favorable diagnostic prediction ability. Next, key gene regulatory networks were constructed and single-gene GSEA analysis was performed. In addition, based on a single-cell dataset from OP, single-cell differentially expressed genes (scDEGs) were identified. The results revealed that aging-related and mitochondria-related genes (AR&MRGs) were enriched in the ERK pathway in tissue stem cells (TSCs), and in mitochondrial membrane potential depolarization in monocytes. Cellular communication analysis showed that TSCs were active, with numerous signaling interactions with monocytes, macrophages and immune cells. Finally, the expression of key gene was verified by quantitative real-time PCR (qRT-PCR). This study is expected to provide strategies for the diagnosis and treatment of OP targeting aging and mitochondria.

Osteoporosis: Causes, Mechanisms, Treatment and Prevention: Role of Dietary Compounds

Osteoporosis is a chronic disease that is characterized by a loss of bone density, which mainly affects the microstructure of the bones due to a decrease in bone mass, thereby making them more fragile and susceptible to fractures. Osteoporosis is currently considered one of the pandemics of the 21st century, affecting around 200 million people. Its most serious consequence is an increased risk of bone fractures, thus making osteoporosis a major cause of disability and even premature death in the elderly. In this review, we discuss its causes, the biochemical mechanisms of bone regeneration, risk factors, pharmacological treatments, prevention and the effects of diet, focusing in this case on compounds present in a diet that could have palliative and preventive effects and could be used as concomitant treatments to drugs, which are and should always be the first option. It should be noted as a concluding remark that non-pharmacological treatments such as diet and exercise have, or should have, a relevant role in supporting pharmacology, which is the recommended prescription today, but we cannot ignore that they can have a great relevance in the treatment of this disease.

Sea buckthorn and its flavonoids isorhamnetin, quercetin, and kaempferol favorably influence bone and breast tissue health

Bone tissue and breast tissue are interrelated, as demonstrated by breast microcalcifications, breast cancer bone metastases, bone morphogenetic proteins, and Wnt signaling. In addition, osteoblasts and osteoclasts represent an important switch of tumor cell dormancy during bone metastasis. Damage to both types of tissues mentioned above is highly prevalent, especially in postmenopausal women, and manifests itself in osteoporosis and breast cancer. Sea buckthorn (Elaeagnus rhamnoides L.), a botanical drug with high antioxidant, antitumor, anti-inflammatory, immunomodulatory, and regenerative properties, has great therapeutic potential due to the unique composition of its bioactive metabolites. This review aimed to summarize the current knowledge from in vitro and in vivo studies on the effect of sea buckthorn, as well as its most widespread flavonoids isorhamnetin, quercetin, and kaempferol, on bone and breast tissue health. In vitro studies have revealed the beneficial impacts of sea buckthorn and aforementioned flavonoids on both bone health (bone remodeling, mineralization, and oxidative stress) and breast tissue health (cancer cell proliferation, apoptosis, tumor growth, and metastatic behavior). In vivo studies have documented their protective effects against disturbed bone microarchitecture and reduced bone strength in animal models of osteoporosis, as well as against tumor expansion and metastatic properties in animal xenograft models. In any case, further research and clinical trials are needed to carefully evaluate the potential therapeutic benefits of sea buckthorn and its flavonoids. Based on the available information, however, it can be concluded that these bioactive metabolites favorably affect both bone and breast tissue health.

A potential function for MicroRNA-124 in normal and pathological bone conditions

Cells produce short single-stranded non-coding RNAs (ncRNAs) called microRNAs (miRNAs), which actively regulate gene expression at the posttranscriptional level. Several miRNAs have been observed to exert significant impacts on bone health and bone-related disorders. One of these, miR-124, is observed in bone microenvironments and is conserved across species. It affects bone cell growth and differentiation by activating different transcription factors and signaling pathways. In-depth functional analyses of miR-124 have revealed several physiological and pathological roles exerted through interactions with other ncRNAs. Deciphering these RNA-mediated signaling networks and pathways is essential for understanding the potential impacts of dysregulated miRNA functions on bone biology. In this review, we aim to provide a comprehensive analysis of miR-124's involvement in bone physiology and pathology. We highlight the importance of miR-124 in controlling transcription factors and signaling pathways that promote bone growth. This review reveals therapeutic implications for the treatment of bone-related diseases.

Exosomes derived from BMSCs in osteogenic differentiation promote type H blood vessel angiogenesis through miR-150-5p mediated metabolic reprogramming of endothelial cells

Osteogenesis is tightly coupled with angiogenesis spatiotemporally. Previous studies have demonstrated that type H blood vessel formed by endothelial cells with high expression of CD31 and Emcn (CD31hi Emcnhi ECs) play a crucial role in bone regeneration. The mechanism of the molecular communication around CD31hi Emcnhi ECs and bone mesenchymal stem cells (BMSCs) in the osteogenic microenvironment is unclear. This study indicates that exosomes from bone mesenchymal stem cells with 7 days osteogenic differentiation (7D-BMSCs-exo) may promote CD31hi Emcnhi ECs angiogenesis, which was verified by tube formation assay, qRT-PCR, Western blot, immunofluorescence staining and µCT assays etc. in vitro and in vivo. Furthermore, by exosomal miRNA microarray and WGCNA assays, we identified downregulated miR-150-5p as the most relative hub gene coupling osteogenic differentiation and type H blood vessel angiogenesis. With bioinformatics assays, dual luciferase reporter experiments, qRT-PCR and Western blot assays, SOX2(SRY-Box Transcription Factor 2) was confirmed as a novel downstream target gene of miR-150-5p in exosomes, which might be a pivotal mechanism regulating CD31hi Emcnhi ECs formation. Additionally, JC-1 immunofluorescence staining, Western blot and seahorse assay results showed that the overexpression of SOX2 could shift metabolic reprogramming from oxidative phosphorylation (OXPHOS) to glycolysis to enhance the CD31hi Emcnhi ECs formation. The PI3k/Akt signaling pathway might play a key role in this process. In summary, BMSCs in osteogenic differentiation might secrete exosomes with low miR-150-5p expression to induce type H blood vessel formation by mediating SOX2 overexpression in ECs. These findings might reveal a molecular mechanism of osteogenesis coupled with type H blood vessel angiogenesis in the osteogenic microenvironment and provide a new therapeutic target or cell-free remedy for osteogenesis impaired diseases.

Capsaicin attenuates Porphyromonas gingivalis-suppressed osteogenesis of periodontal ligament stem cells via regulating mitochondrial function and activating PI3K/AKT/mTOR pathway

BACKGROUND AND OBJECTIVE

Prevention of periodontal bone resorption triggered by Porphyromonas gingivalis (P. gingivalis) is crucial for dental stability. Capsaicin, known as the pungent ingredient of chili peppers, can activate key signaling molecules involved in osteogenic process. However, the effect of capsaicin on osteogenesis of periodontal ligament stem cells (PDLSCs) under inflammation remains elusive.

METHODS

P. gingivalis culture suspension was added to mimic the inflammatory status after capsaicin pretreatment. The effects of capsaicin on the osteogenesis of PDLSCs, as well as mitochondrial morphology, Ca2+ level, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and osteogenesis-regulated protein expression levels were analyzed. Furthermore, a mouse experimental periodontitis model was established to evaluate the effect of capsaicin on alveolar bone resorption and the expression of osteogenesis-related proteins.

RESULTS

Under P. gingivalis stimulation, capsaicin increased osteogenesis of PDLSCs. Not surprisingly, capsaicin rescued the damage to mitochondrial morphology, decreased the concentration of intracellular Ca2+ and ROS, enhanced MMP and activated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. The in vivo results showed that capsaicin significantly attenuated alveolar bone loss and augmented the expression of bone associated proteins.

CONCLUSION

Capsaicin increases osteogenesis of PDLSCs under inflammation and reduces alveolar bone resorption in mouse experimental periodontitis.

Mg-Cross-Linked Alginate Hydrogel Induces BMSC/Macrophage Crosstalk to Enhance Bone Tissue Regeneration via Dual Promotion of the Ligand-Receptor Pairing of the OSM/miR-370-3p-gp130 Signaling Pathway

Macrophages play a pivotal role in the crosstalk between the immune and skeletal systems, while Mg-based biomaterials demonstrate immunomodulatory capabilities in this procedure. However, the mechanism of how Mg2+ promotes osteogenesis through the interplay of bone marrow-derived mesenchymal stem cells (BMSCs) and macrophages remains undescribed. Here, we demonstrated that a Mg-cross-linked alginate hydrogel exerted a dual enhancement of BMSCs osteogenic differentiation through the ligand-receptor pairing of the OSM/miR-370-3p-gp130 axis. On the one hand, Mg2+, released from the Mg-cross-linked hydrogel, stimulates bone marrow-derived macrophages to produce and secrete more OSM. On the other hand, Mg2+ lowers the miR-370-3p level in BMSCs and in turn, reverses its suppression on gp130. Then, the OSM binds to the gp130 heterodimer receptor and activates intracellular osteogenic programs in BMSCs. Taken together, this study reveals a novel cross-talk pattern between the skeletal and immune systems under Mg2+ stimulation. This study not only brings new insights into the immunomodulatory properties of Mg-based biomaterials for orthopedic applications but also enriches the miRNA regulatory network and provides a promising target to facilitate bone regeneration in large bone defects.

Kaempferol attenuates particle-induced osteogenic impairment by regulating ER stress via the IRE1α-XBP1s pathway

Periprosthetic osteolysis and subsequent aseptic loosening are the primary causes of failure following total joint arthroplasty. Wear particle-induced osteogenic impairment is recognized as an important contributing factor in the development of osteolysis, with endoplasmic reticulum (ER) stress emerging as a pivotal underlying mechanism. Hence, searching for potential therapeutic targets and agents capable of modulating ER stress in osteoblasts is crucial for preventing aseptic loosening. Kaempferol (KAE), a natural flavonol compound, has shown promising osteoprotective effects and anti-ER stress properties in diverse diseases. However, the influence of KAE on ER stress-mediated osteogenic impairment induced by wear particles remains unclear. In this study, we observed that KAE effectively relieved TiAl6V4 particles-induced osteolysis by improving osteogenesis in a mouse calvarial model. Furthermore, we demonstrated that KAE could attenuate ER stress-mediated apoptosis in osteoblasts exposed to TiAl6V4 particles, both in vitro and in vivo. Mechanistically, our results revealed that KAE mitigated ER stress-mediated apoptosis by upregulating the IRE1α-XBP1s pathway while concurrently partially inhibiting the IRE1α-regulated RIDD and JNK activation. Collectively, our findings suggest that KAE is a prospective therapeutic agent for treating wear particle-induced osteolysis and highlight the IRE1α-XBP1s pathway as a potential therapeutic target for preventing aseptic loosening.

The mechanism of lncRNA MALAT1 targeting the miR-124-3p/IGF2BP1 axis to regulate osteogenic differentiation of periodontal ligament stem cells

OBJECTIVES

This study aimed to investigate the regulatory roles of lncRNA MALAT1, miR-124-3p, and IGF2BP1 in osteogenic differentiation of periodontal ligament stem cells (PDLSCs).

MATERIALS AND METHODS

We characterized PDLSCs by employing quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analyses to evaluate the expression of key osteogenic markers including ALPL, SPP1, and RUNX2. Manipulation of lncRNA MALAT1 and miR-124-3p expression levels was achieved through transfection techniques. In addition, early osteogenic differentiation was assessed via Alkaline phosphatase (ALP) staining, and mineral deposition was quantified using Alizarin Red S (ARS) staining. Cellular localization of lncRNA MALAT1 was determined through Fluorescence In Situ Hybridization (FISH). To elucidate the intricate regulatory network, we conducted dual-luciferase reporter assays to decipher the binding interactions between lncRNA MALAT1 and miR-124-3P as well as between miR-124-3P and IGF2BP1.

RESULTS

Overexpression of lncRNA MALAT1 robustly promoted osteogenesis in PDLSCs, while its knockdown significantly inhibited the process. We confirmed the direct interaction between miR-124-3p and lncRNA MALAT1, underscoring its role in impeding osteogenic differentiation. Notably, IGF2BP1 was identified as a direct binding partner of lncRNA MALAT1, highlighting its pivotal role within this intricate network. Moreover, we determined the optimal IGF2BP1 concentration (50 ng/ml) as a potent enhancer of osteogenesis, effectively countering the inhibition induced by si-MALAT1. Furthermore, in vivo experiments utilizing rat calvarial defects provided compelling evidence, solidifying lncRNA MALAT1's crucial role in bone formation.

CONCLUSIONS

Our study reveals the regulatory network involving lncRNA MALAT1, miR-124-3p, and IGF2BP1 in PDLSCs' osteogenic differentiation.

CLINICAL RELEVANCE

These findings enhance our understanding of lncRNA-mediated osteogenesis, offering potential therapeutic implications for periodontal tissue regeneration and the treatment of bone defects.

Kaempferol improves Pb-induced cognitive impairments via inhibiting autophagy

Kaempferol (Kam) is a flavonoid antioxidant found in fruits and vegetables, which was discovered as neuroprotective antioxidants. Lead (Pb), an environmental pollution, could induce learning and memory deficits. Nevertheless, little is known about the mechanisms underlying Kam actions in Pb-induced learning and memory deficits. In this study, we investigated the effects of Kam on Pb-induced cognitive deficits. Pb-exposed rats were treated with 50 mg/kg Kam from postnatal day (PND) 30 to PND 60. Then, Y-maze and Morris water maze have been used to detect the spatial memory in all groups of rats. Hematoxylin and eosin (HE) staining and Nissl staining were used to analyze the neuronal structure damages. The results found Kam treatment improved the learning and memory ability and alleviated hippocampal neuronal pathological damages. Besides, Kam could significantly reverse the synaptic transmission related protein expression including PSD95 and NMDAR2B. Further research found that Kam downregulated autophagy markers, P62, ATG5, Beclin1, and LC3-II. Furthermore, 3-MA, autophagy inhibitor, increased the levels of NMDAR2B and PSD95 in Pb-induced PC12 cells, indicating Kam alleviated Pb-induced neurotoxicity through inhibiting autophagy activation. Our results showed that Kam could ameliorate Pb-induced cognitive impairments and neuronal damages by decreasing Pb-induced excess autophagy accumulation.

Mangiferin attenuates osteoporosis by inhibiting osteoblastic ferroptosis through Keap1/Nrf2/SLC7A11/GPX4 pathway

BACKGROUND

Ferroptosis is a crucial contributor to impaired osteoblast function in osteoporosis. Mangiferin, a xanthonoid glucoside isolated from mangoes, exhibits anti-osteoporosis effects. However, its potential mechanism is not fully understood.

PURPOSE

This study explores the potencies of mangiferin on osteoblastic ferroptosis and deciphers its direct target in the context of solute carrier family 7-member 11 (SLC7A11)/glutathione peroxidases 4 (GPX4) pathway.

METHODS

In vivo models include bilateral ovariectomy induced osteoporosis mice, iron-dextran induced iron-overloaded mice, and nuclear factor-erythroid 2-related factor 2 (Nrf2)-knockout mice. Mice are orally administrated mangiferin (10, 50 or 100 mg.kg-1.d-1) for 12 weeks. In vitro osteoblast models include iron-dextran induced iron-overloaded cells, erastin induced ferroptosis cells, and gene knockout cells. RNA sequencing is applied for investigating the underlying mechanisms. The direct target of mangiferin is studied using a cellular thermal shift assay, silico docking, and surface plasmon resonance.

RESULTS

Mangiferin promotes bone formation and inhibits ferroptosis in vivo models (osteoporosis mice, iron-overloaded mice) and in vitro models (ferroptosis osteoblast, iron-overloaded osteoblasts). Mechanismly, mangiferin directly binds to the kelch-like ECH-associated protein 1 (Keap1) and activates the downstream Nrf2/SLC7A11/GPX4 pathway in both the in vivo and in vitro models. Mangiferin failed to restore the osteoporosis and ferroptosis in Nrf2-knockout mice. Silencing Nrf2, SLC7A11 or GPX4 abolished the anti-ferroptosis effect of mangiferin in erastin-induced cells. Addition of the ferroptosis agonist RSL-3 also blocked the protective effects of mangiferin on iron-overloaded cells. Furthermore, mangiferin had better effects on osteogenesis than the ferroptosis inhibitor (ferrostatin-1) and the Nrf2 agonists (sulforaphane, dimethyl fumarate, and bardoxolone).

CONCLUSIONS

We identify for the first time mangiferin as a ferroptosis inhibitor and a direct Keap1 conjugator that promotes bone formation and alleviates osteoporosis. This work also provides a potentially practical pharmacological approach for treating ferroptosis-driven diseases.

Identification of Drug Targets and Agents Associated with Ferroptosis-related Osteoporosis through Integrated Network Pharmacology and Molecular Docking Technology

BACKGROUND

Osteoporosis is a systemic bone disease characterized by progressive reduction of bone mineral density and degradation of trabecular bone microstructure. Iron metabolism plays an important role in bone; its imbalance leads to abnormal lipid oxidation in cells, hence ferroptosis. In osteoporosis, however, the exact mechanism of ferroptosis has not been fully elucidated.

OBJECTIVE

The main objective of this project was to identify potential drug target proteins and agents for the treatment of ferroptosis-related osteoporosis.

METHODS

In the current study, we investigated the differences in gene expression of bone marrow mesenchymal stem cells between osteoporosis patients and normal individuals using bioinformatics methods to obtain ferroptosis-related genes. We could predict their protein structure based on the artificial intelligence database of AlphaFold, and their target drugs and binding sites with the network pharmacology and molecular docking technology.

RESULTS

We identified five genes that were highly associated with osteoporosis, such as TP53, EGFR, TGFB1, SOX2 and MAPK14, which, we believe, can be taken as the potential markers and targets for the diagnosis and treatment of osteoporosis. Furthermore, we observed that these five genes were highly targeted by resveratrol to exert a therapeutic effect on ferroptosis-related osteoporosis.

CONCLUSION

We examined the relationship between ferroptosis and osteoporosis based on bioinformatics and network pharmacology, presenting a promising direction to the pursuit of the exact molecular mechanism of osteoporosis so that a new target can be discovered for the treatment of osteoporosis.

Disulfidptosis-related Protein RPN1 may be a Novel Anti-osteoporosis Target of Kaempferol

BACKGROUND

Osteoporosis (OP) is an age-related skeletal disease. Kaempferol can regulate bone mesenchymal stem cells (BMSCs) osteogenesis to improve OP, but its mechanism related to disulfidptosis, a newly discovered cell death mechanism, remains unclear.

OBJECTIVE

The study aimed to investigate the biological function and immune mechanism of disulfidptosis- related ribophorin I (RPN1) in OP and to experimentally confirm that RPN1 is the target for the treatment of OP with kaempferol.

METHODS

Differential expression analysis was conducted on disulfide-related genes extracted from the GSE56815 and GSE7158 datasets. Four machine learning algorithms identified disease signature genes, with RPN1 identified as a significant risk factor for OP through the nomogram. Validation of RPN1 differential expression in OP patients was performed using the GSE56116 dataset. The impact of RPN1 on immune alterations and biological processes was explored. Predictive ceRNA regulatory networks associated with RPN1 were generated via miRanda, miRDB, and TargetScan databases. Molecular docking estimated the binding model between kaempferol and RPN1. The targeting mechanism of kaempferol on RPN1 was confirmed through pathological HE staining and immunohistochemistry in ovariectomized (OVX) rats.

RESULTS

RPN1 was abnormally overexpressed in the OP cohort, associated with TNF signaling, hematopoietic cell lineage, and NF-kappa B pathway. Immune infiltration analysis showed a positive correlation between RPN1 expression and CD8+ T cells and resting NK cells, while a negative correlation with CD4+ naive T cells, macrophage M1, T cell gamma delta, T cell follicular helper cells, activated mast cells, NK cells, and dendritic cells, was found. Four miRNAs and 17 lncRNAs associated with RPN1 were identified. Kaempferol exhibited high binding affinity (-7.2 kcal/mol) and good stability towards the RPN1. The experimental results verified that kaempferol could improve bone microstructure destruction and reverse the abnormally high expression of RPN1 in the femur of ovariectomized rats.

CONCLUSION

RPN1 may be a new diagnostic biomarker in patients with OP, and may serve as a new target for kaempferol to improve OP.

Targeted Inhibition of the PI3K/Akt/mTOR Signaling Axis: Potential for Sarcoma Therapy

Sarcoma is a heterogeneous group of malignancies often resistant to conventional chemotherapy and radiation therapy. The phosphatidylinositol-3-kinase/ protein kinase B /mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway has emerged as a critical cancer target due to its central role in regulating key cellular processes such as cell growth, proliferation, survival, and metabolism. Dysregulation of this pathway has been implicated in the development and progression of bone sarcomas (BS) and soft tissue sarcomas (STS). PI3K/Akt/mTOR inhibitors have shown promising preclinical and clinical activity in various cancers. These agents can inhibit the activation of PI3K, Akt, and mTOR, thereby reducing the downstream signaling events that promote tumor growth and survival. In addition, PI3K/Akt/mTOR inhibitors have been shown to enhance the efficacy of other anticancer therapies, such as chemotherapy and radiation therapy. The different types of PI3K/Akt/mTOR inhibitors vary in their specificity, potency, and side effect profiles and may be effective depending on the specific sarcoma type and stage. The molecular targeting of PI3K/Akt/mToR pathway using drugs, phytochemicals, nanomaterials (NMs), and microbe-derived molecules as Pan-PI3K inhibitors, selective PI3K inhibitors, and dual PI3K/mTOR inhibitors have been delineated. While there are still challenges to be addressed, the preclinical and clinical evidence suggests that these inhibitors may significantly improve patient outcomes. Further research is needed to understand the potential of these inhibitors as sarcoma therapeutics and to continue developing more selective and effective agents to meet the clinical needs of sarcoma patients.

Cornus officinalis: a potential herb for treatment of osteoporosis

Osteoporosis (OP) is a systemic metabolic skeletal disorder characterized by a decline in bone mass, bone mineral density, and deterioration of bone microstructure. It is prevalent among the elderly, particularly postmenopausal women, and poses a substantial burden to patients and society due to the high incidence of fragility fractures. Kidney-tonifying Traditional Chinese medicine (TCM) has long been utilized for OP prevention and treatment. In contrast to conventional approaches such as hormone replacement therapy, TCM offers distinct advantages such as minimal side effects, low toxicity, excellent tolerability, and suitability for long-term administration. Extensive experimental evidence supports the efficacy of kidney-tonifying TCM, exemplified by formulations based on the renowned herb Cornus officinalis and its bioactive constituents, including morroniside, sweroside, flavonol kaempferol, Cornuside I, in OP treatment. In this review, we provide a comprehensive elucidation of the underlying pathological principles governing OP, with particular emphasis on bone marrow mesenchymal stem cells, the homeostasis of osteogenic and osteoclastic, and the regulation of vascular and immune systems, all of which critically influence bone homeostasis. Furthermore, the therapeutic mechanisms of Cornus officinalis-based TCM formulations and Cornus officinalis-derived active constituents are discussed. In conclusion, this review aims to enhance understanding of the pharmacological mechanisms responsible for the anti-OP effects of kidney-tonifying TCM, specifically focusing on Cornus officinalis, and seeks to explore more efficacious and safer treatment strategies for OP.

Exploring the mechanism of Astragali radix for promoting osteogenic differentiation based on network pharmacology, molecular docking, and experimental validation

The present study used network pharmacology and molecular docking to predict the active ingredients and mechanisms of action of Astragalus radix (AR) to promote osteogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs), and cell experiments were conducted for verification. First, network pharmacology was used to predict the effective components, targets, and mechanisms of action of AR to promote osteogenic differentiation. The effective components and corresponding target proteins of AR, and the target proteins of osteogenic differentiation were collected through the database. The intersection targets of the two were used for the construction and analysis of a protein-protein interaction (PPI) network. Gene Oncology (GO) and Kyoto Encyclopedia of Genes, and Genomes (KEGG) enrichment analyses were conducted. Next, molecular docking technology was carried out to verify the interaction between the active ingredient and the target protein, and to select the appropriate effective active ingredient. Finally, the results of network pharmacology analysis were verified by in vitro experiments. A total of 95 potential targets were retrieved by searching the intersection of AR and osteogenic differentiation targets. PPI network analysis indicated that RAC-α-serine-threonine-protein kinase (Akt1) was considered to be the most reliable target for AR to regulate osteogenic differentiation. GO enrichment analysis included 21 biological processes, 21 cellular components and 100 molecular functions. KEGG enrichment analysis indicated that the class I phosphatidylinositol-3 kinase (PI3K)-serine-threonine kinase (Akt) signaling pathway may play an important role in promoting osteogenic differentiation. The results of molecular docking showed that quercetin's performance was improved compared with that of kaempferol. In vitro experiments showed that quercetin promoted the expression of osteogenic marker proteins (including collagen I, Runt-related transcription factor 2 and osteopontin) in BMSCs and activated the PI3K/Akt signaling pathway. AR acted on Akt1 targets through its main active component quercetin, and promoted the osteogenic differentiation of BM-MSCs by activating the PI3K/Akt signaling pathway.

HIF-1α increases the osteogenic capacity of ADSCs by coupling angiogenesis and osteogenesis via the HIF-1α/VEGF/AKT/mTOR signaling pathway

BACKGROUND

Stabilization and increased activity of hypoxia-inducible factor 1-α (HIF-1α) can directly increase cancellous bone formation and play an essential role in bone modeling and remodeling. However, whether an increased HIF-1α expression in adipose-derived stem cells (ADSCs) increases osteogenic capacity and promotes bone regeneration is not known.

RESULTS

In this study, ADSCs transfected with small interfering RNA and HIF-1α overexpression plasmid were established to investigate the proliferation, migration, adhesion, and osteogenic capacity of ADSCs and the angiogenic ability of human umbilical vein endothelial cells (HUVECs). Overexpression of HIF-1α could promote the biological functions of ADSCs, and the angiogenic ability of HUVECs. Western blotting showed that the protein levels of osteogenesis-related factors were increased when HIF-1α was overexpressed. Furthermore, the influence of upregulation of HIF-1α in ADSC sheets on osseointegration was evaluated using a Sprague-Dawley (SD) rats implant model, in which the bone mass and osteoid mineralization speed were evaluated by radiological and histological analysis. The overexpression of HIF-1α in ADSCs enhanced bone remodeling and osseointegration around titanium implants. However, transfecting the small interfering RNA (siRNA) of HIF-1α in ADSCs attenuated their osteogenic and angiogenic capacity. Finally, it was confirmed in vitro that HIF-1α promotes osteogenic differentiation and the biological functions in ADSCs via the VEGF/AKT/mTOR pathway.

CONCLUSIONS

This study demonstrates that HIF-1α has a critical ability to promote osteogenic differentiation in ADSCs by coupling osteogenesis and angiogenesis via the VEGF/AKT/mTOR signaling pathway, which in turn increases osteointegration and bone formation around titanium implants.

Chimaphila umbellata; a biotechnological perspective on the coming-of-age prince's pine

Chimaphila umbellata has been studied for almost two centuries now, with the first paper exploring the phytochemistry of the plant published in 1860. Almost all contemporary studies focus on the biotechnological advances of C. umbellata including its utilization as a natural alternative in the cosmetic, food, biofuel, and healthcare industry, with a special focus on its therapeutic uses. This literature review critically investigates the significance and applications of secondary metabolites extracted from the plant and presses on the biotechnological approaches to improve its utilization. C. umbellata is home to many industrially and medicinally important phytochemicals, the majority of which belong to phenolics, sterols, and triterpenoids. Other important compounds include 5-hydroxymethylfurfural, isohomoarbutin, and methyl salicylate (the only essential oil of the plant). Chimaphilin is the characteristic phytochemical of the plant. This review focuses on the phytochemistry of C. umbellata and digs into their chemical structures and attributes. It further discusses the challenges of working with C. umbellata including its alarming conservation status, problems with in-vitro cultivation, and research and development issues. This review concludes with recommendations based on biotechnology, bioinformatics, and their crucial interface.

Deciphering the protective effect of Buzhong Yiqi Decoction on osteoporotic fracture through network pharmacology and experimental validation

BACKGROUND

Osteoporotic fracture (OPF) is one of the most common skeletal diseases in an aging society. The Chinese medicine formula Buzhong Yiqi Decoction (BZYQD) is commonly used for treating OPF. However, the essential bioactive compounds and the underlying molecular mechanisms that promote fracture repair remain unclear.

METHODS

We used network pharmacology and experimental animal validation to address this issue. First, 147 bioactive BZYQD compounds and 32 target genes for treating OPF were screened and assessed. A BZYQD-bioactive compound-target gene-disease network was constructed using the Cytoscape software. Functional enrichment showed that the candidate target genes were enriched in oxidative stress- and inflammation-related biological processes and multiple pathways, including nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways. Furthermore, an OPF rat model was established and treated with BZYQD.

RESULTS

The results revealed that BZYQD ameliorated OPF characteristics, including femoral microarchitecture, biomechanical properties, and histopathological changes, in a dose-dependent manner. Results of enzyme-linked immunosorbent assay showed that BZYQD reduced the serum's pro-inflammatory cytokines [Tumor necrosis factor-alpha (TNF-α), Interleukin (IL)-1β, and IL-6] and improved oxidative stress-related factors [glutathione (GSH) and superoxide dismutase (SOD)]. BZYQD significantly decreased the protein expression of NF-κB in OPF rat femurs, suppressed NF-κB activation, and activated the nuclear factor-erythroid factor 2-related factor (Nrf2)/heme oxygenase 1 (HO-1) and p38 MAPK as well ERK pathways.

CONCLUSIONS

Our results suggest that BZYQD could improve inflammation and oxidative stress during fracture repair by suppressing NF-κB and activating Nrf2/MAPK signaling pathways.

Study on the treatment of postmenopausal osteoporosis with quercetin in Liuwei Dihuang Pill based on network pharmacology

BACKGROUND

Liuwei Dihuang Pill (LP) was verified to alleviate postmenopausal osteoporosis (PMOP) development. Nevertheless, the major constituent of LP and the related network pharmacology study remain unexplored.

METHODS

Protein-protein interaction was established to identify the downstream target of LP in PMOP, and the related signaling pathway was investigated by bioinformatics analysis. MC3T3-E1 cells were added to ferric ammonium citrate (FAC) to mimic osteoporosis in vitro. The osteoblasts were identified by Alizarin red staining. Western blot was applied to evaluate protein levels. In addition, Cell Counting Kit-8 (CCK8) assay was applied to assess cell viability, and cell apoptosis was assessed by flow cytometry.

RESULTS

Quercetin was the major constituent of LP. In addition, quercetin significantly reversed FAC-induced inhibition of osteogenic differentiation in MC3T3-E1 cells. In addition, quercetin notably abolished the FAC-induced upregulation of Bax, Caspase-3, FOS, JUN, TGFB1 and PPARD. In contrast, Bcl-2, p-mTOR/mTOR, p-AKT/AKT and p-PI3K/PI3K levels in MC3T3-E1 cells were reduced by FAC, which was restored by quercetin. Meanwhile, FAC notably inhibited the viability of MC3T3-E1 cells via inducing apoptosis, but this impact was abolished by quercetin. Furthermore, quercetin could reverse pcDNA3.1-FOS-mediated growth of FAC-treated osteoblasts by mediating PI3K/AKT/mTOR signaling.

CONCLUSION

Quercetin alleviated the progression of PMOP via activation of PI3K/AKT/mTOR signaling. Hence, this study would shed novel insights into discovering new methods against PMOP.