Dexamethasone induces osteoblast apoptosis through ROS-PI3K/AKT/GSK3β signaling pathway

Modulation of HIF-1α and TNF-α in pre-osteoblasts treated with alcohol extract of propolis: Implications for cellular response and signaling pathways

Numerous studies have demonstrated the significant role of propolis in various biological processes, including inflammation and the repair of endothelial and bone tissues. The cascade of inflammation, proliferation, and tissue remodeling characterizes the injury site. Remarkable progress has been made in the field of alternative medicine with the utilization of propolis. In this study, we specifically investigated the effects of alcoholic extract of propolis on cell adhesion, survival, remodeling, and differentiation pathways in osteoblasts. Our findings revealed the activation of survival proteins such as AKT, ERK, and phosphorylated ERK during the adhesion phase, while interleukins, specifically IL-6 and TNF, exhibited increased expression during cell differentiation. Furthermore, treatment with propolis extract led to enhanced activity of metalloproteinases (MMP9 and MMP2) and HIF-1α, a crucial activator of angiogenesis and bone remodeling. It was observed that the alcoholic propolis extract stimulated cell proliferation, differentiation, and repair, with key molecules involved in these processes including pro-inflammatory factors IL-6 and TNFα, as well as HIF-1, MMP2, and BMP7 proteins. Collectively, these factors induced an initial state of proliferation followed by differentiation and repair. Therefore, the alcoholic extract of propolis holds promise as a potential therapeutic agent, particularly in cases involving tissue repair. Nevertheless, further comprehensive in vitro and in vivo studies targeting this area are necessary to advance our understanding.

In Silico Screening and Identification of Functional Peptides from Yak Bone Collagen Hydrolysates: Antioxidant and Osteoblastic Activities

Collagen peptides are recognized for their diverse bioactivities; however, efficiently screening potent peptides from hydrolysates remains challenging. This study employed an integrated strategy that combined in silico antioxidant activity prediction and molecular docking to myeloperoxidase (MPO) to screen active peptides derived from yak bone collagen hydrolysates. Focusing on low molecular weight peptides, containing motifs such as GVM, GLP, GPM, and GPQ, we identified nine antioxidant peptides (KC1-KC9). Their activities were validated through in vitro free radical scavenging assays, with peptide KC7 demonstrating superior performance. Furthermore, peptide KC7 promoted proliferation, differentiation, and mineralization in MC3T3-E1 cells by upregulating osteogenic markers such as Runx2 and osteocalcin, modulating the Wnt/β-catenin and PI3K/Akt pathways, and reducing the Bax/Bcl-2 ratio. These results highlight KC7's dual capacity to mitigate oxidative stress and potentially reduce apoptotic susceptibility, thereby stimulating osteogenesis. This positions peptide KC7 as a promising candidate for bone regeneration and oxidative stress-related disorders. Moreover, this study underscores the effectiveness of integrating computational and experimental approaches for the discovery of multifunctional natural peptides.

Monoallelic loss-of-function variants in GSK3B lead to autism and developmental delay

De novo variants adjacent to the canonical splicing sites or in the well-defined splicing-related regions are more likely to impair splicing but remain under-investigated in autism spectrum disorder (ASD). By analyzing large, recent ASD genome sequencing cohorts, we find a significant burden of de novo potential splicing-disrupting variants (PSDVs) in 5048 probands compared to 4090 unaffected siblings. We identified 55 genes with recurrent de novo PSDVs that were highly intolerant to variation. Forty-six of these genes have not been strongly implicated in ASD or other neurodevelopmental disorders previously, including GSK3B. Through international, multicenter collaborations, we assembled genotype and phenotype data for 15 individuals with GSK3B variants and identified common phenotypes including developmental delay, ASD, sleeping disturbance, and aggressive behavior. Using available single-cell transcriptomic data, we show that GSK3B is enriched in dorsal progenitors and intermediate forms of excitatory neurons in the developing brain. We showed that Gsk3b knockdown in mouse excitatory neurons interferes with dendrite arborization and spine maturation which could not be rescued by de novo missense variants identified from affected individuals. In summary, our findings suggest that PSDVs may play an important role in the genetic etiology of ASD and allow for the prioritization of new ASD candidate genes. Importantly, we show that genetic variation resulting in GSK3B loss-of-function can lead to a neurodevelopmental disorder with core features of ASD and developmental delay.

Nobiletin ameliorates hormone-induced osteoblast apoptosis by modulating JAK2/STAT3 signaling

Our paper aimed to disclose the effects of nobiletin (NOB) on hormone-induced osteoblast apoptosis and potential action mechanism. MC3T3-E1 cells were randomly separated into normal group, glucocorticoid (GC) group, L-NOB group, M-NOB group, H-NOB group, and Colivelin group (Colivelin: JAK2/STAT3 activator). CCK-8 was applied to ascertain the activity of MC3T3-E1 cells. FITC-Annexin V/PI method was applied to measure cell apoptosis. Alkaline phosphatase (ALP) assay kit was applied to measure ALP activity. Enzyme linked immunosorbent assay (ELISA) was implemented to ascertain the levels of IL-6, IL-1β, TNF-α, and ROS. Western blotting was implemented to distinguish the expressions of JAK2/STAT3 pathway proteins. The viability of MC3T3-E1 cells, ALP activities, and bcl-2 protein level were considerably decreased, while the apoptotic rate, the levels of TNF-α, IL-1β, IL-6, ROS, and the expressions of pJAK2/JAK2, pSTAT3/STAT3, Caspase-3, and bax proteins were greatly increased in each group after GC treatment. In comparison with GC group, MC3T3-E1 cell viability, ALP activity, and bcl-2 protein level in the L-NOB group, M-NOB group, and H-NOB group were greatly increased. Conversely, the apoptotic rate, the levels of TNF-α, IL-1β, IL-6, ROS, and the expressions of pJAK2/JAK2, pSTAT3/STAT3, Caspase-3, and bax proteins were markedly reduced. In contrast to H-NOB group, the apoptotic rate, the levels of TNF-α, IL-1β, IL-6, ROS, and the expressions of pJAK2/JAK2, pSTAT3/STAT3, Caspase-3, and bax proteins in Colivelin group were considerably enhanced, while MC3T3-E1 cell viability, ALP activity, and bcl-2 protein level were greatly declined. NOB ameliorates hormone-induced osteoblast apoptosis by reducing JAK2/STAT3 signaling activity.

Mechanisms and structure-activity relationships of natural polysaccharides as potential anti-osteoporosis agents: A review

In recent years, polysaccharides derived from natural sources have garnered significant attention due to their safety and potential anti-osteoporotic effects. This review provides a comprehensive overview of the sources, distribution, structures, and mechanisms of anti-osteoporosis polysaccharides, as well as an investigation into their structure-activity relationships. Over thirty distinct, homogenous polysaccharides with anti-osteoporosis properties have been extracted from natural sources, primarily categorized as glucans, fructans, galactomannans, glucomannans, and various other heteropolysaccharides. Natural polysaccharides can effectively enhance osteoblast differentiation and mineralization while suppressing osteoclast activation, with the mechanism regulated by the BMP/SMAD/RUNX2, Wnt/Catenin, OPG/RANKL/RANK, and TLR2/NF-κB/NFATc1 signaling pathways. Furthermore, polysaccharides contribute to the prevention of osteoporosis by mitigating oxidative stress, decreasing inflammation, and modulating the gut microbiota. This review also summarizes the relationship between the monosaccharide composition, molecular weight, and glycosidic bond type of polysaccharides and their anti-osteoporotic activity. A comprehensive summary and analysis of the existing deficiencies and challenges in the research of anti-osteoporotic polysaccharides is also concluded. This review may serve as a significant reference for the discovery and utilization of naturally derived anti-osteoporotic polysaccharides in the pharmaceutical and health industries.

Zuogui Pills alleviate iron overload-induced osteoporosis by attenuating ROS-mediated osteoblast apoptosis via the PI3K-AKT pathway and mitigating mitochondrial damage

ETHNOPHARMACOLOGICAL RELEVANCE

Zuogui Pill (ZGP) is a classic herbal formula in Traditional Chinese Medicine, primarily used to tonify the kidney and replenish essence, and is widely applied in treating various kidney deficiency-related conditions. Over time, ZGP has demonstrated significant efficacy in addressing symptoms such as fatigue, weakness, and soreness of the lower back and knees, which are often caused by kidney deficiency. According to Traditional Chinese Medicine theory, the kidneys govern the bones, meaning that sufficient kidney essence is closely related to bone strength. By nourishing the kidneys and replenishing essence, ZGP helps to increase bone density and improve bone microstructure, making it an important therapeutic option for osteoporosis.

AIM OF THE STUDY

To investigate the protective effects of ZGP in iron overload-induced osteoporosis and elucidate its molecular mechanisms through the activation of the Phosphoinositide 3-Kinase (PI3K)/Protein Kinase B (AKT) and Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2)/Heme Oxygenase-1 (HO-1) pathways, which reduce oxidative stress, inhibit osteoblast apoptosis, and promote osteoblast differentiation and mineralization.

MATERIALS AND METHODS

An in vivo mouse model of iron overload-induced osteoporosis and an in vitro MC3T3-E1 osteoblast model were used. In vitro experiments involved the use of ZGP containing-serum, along with transcriptomic analysis, Western blot, flow cytometry, TUNEL staining, and immunofluorescence, to assess the effects on oxidative stress, mitochondrial function, and apoptosis. In vivo experiments evaluated the effects of ZGP on bone mass, oxidative stress, and apoptosis using Micro-computed tomography (micro-CT), Hematoxylin and eosin staining (H&E), TUNEL staining, and immunohistochemistry.

RESULTS

The study found that ZGP containing-serum significantly enhanced the viability of osteoblasts induced by iron overload and reduced apoptosis through the reactive oxygen species (ROS)-mediated Phosphoinositide 3-Kinase (PI3K)/Protein Kinase B (AKT) pathway while mitigating mitochondrial damage. In vivo, micro-computed tomography results showed that ZGP improved bone mass, and decreased ROS and apoptosis, consistent with the in vitro findings.

CONCLUSION

ZGP demonstrates significant antioxidant and anti-apoptotic effects in iron overload-induced osteoporosis, primarily through the ROS-mediated PI3K/AKT pathway and by reducing mitochondrial damage. These findings suggest that ZGP may be a promising therapeutic agent for treating osteoporosis associated with iron overload.

Knockdown of lncRNA XR_877193.1 suppresses ferroptosis and promotes osteogenic differentiation via the PI3K/AKT signaling pathway in SONFH

Ferroptosis is a novel form of regulated cell death characterized by the iron-dependent accumulation of lipid peroxides. Recent research has suggested that ferroptosis in osteoblasts contributes to steroid-induced osteonecrosis of the femoral head (SONFH). However, the relationship between ferroptosis and SONFH remains unclear. In this study, in vitro experiments show that dexamethasone (Dex) treatment reduces the expressions of key ferroptosis regulators, SLC7A11 and GPX4, in MC3T3-E1 cells. This reduction leads to a decrease in intracellular glutathione (GSH) levels, accompanied by elevated levels of total iron, malondialdehyde (MDA), and reactive oxygen species (ROS). Importantly, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively reverses Dex-induced ferroptosis in MC3T3-E1 cells. Furthermore, RNA-seq analysis reveals that the long noncoding RNA (lncRNA) XR_877193.1is significantly upregulated in Dex-treated MC3T3-E1 cells. Functional studies demonstrate that the knockdown of lncRNA XR_877193.1 promotes osteogenic differentiation by inhibiting Dex-induced ferroptosis in MC3T3-E1 cells, whereas its overexpression exacerbates cell death via ferroptosis. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis reveals that the differentially expressed lncRNA XR_877193.1 is enriched in ferroptosis-related pathways, including the PI3K/AKT signaling pathway. Moreover, PI3K/AKT inhibitors reverse ferroptosis in MC3T3-E1 cells inhibited by lncRNA XR_877193.1 knockdown. Collectively, our findings indicate that lncRNA XR_877193.1 knockdown exerts anti-ferroptosis effects by stimulating the PI3K/AKT signaling pathway, suggesting a promising therapeutic strategy for attenuating SONFH.

Treatment with Lactobacillus paracasei L30 extract induces osteogenic differentiation of human bone marrow mesenchymal stem cells in vitro

Bone-related diseases such as osteoporosis pose a significant health economic burden to countries around the world and, because current treatments are insufficient, more effective therapies are desperately needed. This study explored the potential of Lactobacillus paracasei L30 extract to influence the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBM-MSCs). Our results showed that L30 extract significantly enhanced the expression of osteogenic markers in hBM-MSCs, including alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), and collagen type I alpha 1 (COL1A1). Mechanistic studies revealed that L30 extract activated the p38 MAPK and AKT signaling pathways, leading to phosphorylation of Glycogen synthase kinase-3 beta (GSK3β) and subsequent nuclear translocation of β-catenin. Conversely, inhibition of p38 MAPK, AKT, or knockdown of β-catenin significantly attenuated the osteogenic effects of L30 extract on hBM-MSCs. Furthermore, we found that L30 extract promoted osteogenic differentiation in primary osteoblast precursors isolated from mouse calvaria and enhances bone formation in ex vivo calvarial organ cultures. Therefore, the application of Lactobacillus paracasei L30 extract in such contexts could serve as a therapeutic approach for promoting bone formation. Collectively, our findings suggest a novel approach for the clinical management of bone-related disorders, with possible applications for treating diseases such as osteoporosis.

Kushenol O Regulates GALNT7/NF-κB axis-Mediated Macrophage M2 Polarization and Efferocytosis in Papillary Thyroid Carcinoma

BACKGROUND

The incidence of papillary thyroid carcinoma (PTC) is on the rise globally. It is frequently associated with early lymphatic metastasis, and the poor prognosis tends to be poor once metastasis or recurrence occurs, even with current treatment modalities. Kushenol O, a novel extract derived from Sophora flavescens, has shown remarkable anticancer properties. However, its specific role in the treatment of PTC remains to be elucidated.

PURPOSE

This objective of this study is to examine the effects of kushenol O on the proliferation and invasion capacity of PTC cells, as well as to delve into its potential mechanisms of action.

METHODS

Multi-omics was employed to identify the potential therapeutic targets for PTC. Single-cell RNA sequencing (scRNA-seq) investigated how these targets influence the remodeling of the tumor immune microenvironment (TIME). Kushenol O was employed to treat the PTC cell lines, with assessments conducted on its effects regarding cell viability, apoptosis, oxidative stress, and invasiveness. Molecular simulation was used to validate kushenol O's affinity for the therapeutic targets and biological toxicity. The impact of kushenol O was further evaluated using qRT-PCR and EdU assays, while cytotoxicity was measured by the CCK-8.

RESULTS

GALNT7 is a potential new target for the treatment of PTC. It may regulate the macrophage M2 polarization and efferocytosis in the TIME of PTC through regulating the NF-κB axis. Kushenol O inhibits PTC cells proliferation and promotes apoptosis by inhibiting the expression of GALNT7, induces a decrease in SOD levels and an increase in MDA levels by inhibiting mitochondrial function, and promotes the accumulation of ROS, which inhibits G1 phase and promotes early apoptosis.

CONCLUSIONS

Kushenol O may inhibit the inflammation-cancer transformation and tumor progression of PTC by inhibiting GALNT7 and thus regulating NF-κB axis. These findings highlight the potential of kushenol O as immunomodulator or therapeutic agent, which may have important clinical implications.

Pym-18a, a novel pyrimidine derivative ameliorates glucocorticoid induced osteoblast apoptosis and promotes osteogenesis via autophagy and PINK 1/Parkin mediated mitophagy induction

Glucocorticoid-induced osteoporosis (GIOP) is the most common type of secondary osteoporosis, marked by reduced bone density and impaired osteoblast function. Current treatments have serious side effects, highlighting the need for new drug candidates. Pyrimidine derivatives have been noted for their potential in suppressing osteoclastogenesis, but their effects on osteogenesis and GIOP remain underexplored. Our recent study identified a novel pyrimidine derivative, Pym-18a, which enhances osteoblast functions. In this study, Pym-18a was found to mitigate the detrimental effects of Dexamethasone (Dex) in osteoblast cells and in GIOP in Balb/C mice. Pretreatment with Pym-18a followed by Dex (100 µM) for 24 h restored osteoblast alkaline phosphatase activity and viability. Pym-18a reduced Dex-induced apoptosis and reactive oxygen species (ROS) generation at cellular and mitochondrial levels and preserved mitochondrial membrane potential. Dex impaired autophagy and mitophagy, however but Pym-18a pretreatment increased expression of autophagy markers (LC3II) and mitophagy markers (PINK1, Parkin, TOM20) while decreasing P62 expression. The osteogenic effects of Pym-18a were diminished in the presence of 3-MA (an autophagy inhibitor). In silico studies showed mTOR inhibition by Pym-18a, corroborated by its suppression of Dex-induced mTOR activation. In vivo, Pym-18a (10 mg/kg) significantly improved bone microarchitecture, trabecular connectivity, and strength, and corrected P1NP and CTX levels altered by Dex. Pym-18a also promoted autophagy, mitophagy, and suppressed mTOR activation in GIOP mice. Overall, Pym-18a mitigates detrimental effect of Dex by modulating autophagy and PINK/Parkin-mediated mitophagy through mTOR inhibition, suggesting it as a potential novel therapeutic option for GIOP.

Maintaining myoprotein and redox homeostasis via an orally recharged nanoparticulate supplement potentiates sarcopenia treatment

Sarcopenia is a progressive skeletal muscle disorder characterized by the accelerated loss of muscle mass and function, with no promising pharmacotherapies. Understanding the imbalance of myoprotein homeostasis within myotubes, which causes sarcopenia, may facilitate the development of novel treatments for clinical use. In this study, we found a strong correlation between low serum selenium levels and muscle function in elderly patients with sarcopenia. We hypothesized that supplementation with selenium might be beneficial for the management of sarcopenia. To verify this hypothesis, we developed diselenide-bridged mesoporous silica nanoparticles (Se-Se-MSNs) with ROS-responsive degradation and release to supplement selenium. Se-Se-MSNs outperformed free selenocysteine in alleviating sarcopenia in both dexamethasone (Dex)- and denervation-induced mouse models. Subsequently, Se-Se-MSNs were loaded with leucine (Leu@Se-Se-MSNs), another nutritional supplement used in sarcopenia management. Oral administration of Leu@Se-Se-MSNs restored myoprotein homeostasis by enhancing mTOR/S6K signaling and inactivating Akt/FoxO3a/MuRF1 signaling, thus exerting optimal therapeutic effects against sarcopenia and exhibiting a more favorable in vivo safety profile. This study provides a proof of concept for treating sarcopenia by maintaining myoprotein and redox homeostasis simultaneously and offers valuable insights into the development of multifunctional nanoparticle-based supplements for sarcopenia management.

Reducing PDK4 level constitutes a pivotal mechanism for glucocorticoids to impede osteoblastic differentiation through the enhancement of ferroptosis in mesenchymal stem cells

BACKGROUND

This study mainly explores the possible role and mechanism of pyruvate dehydrogenase kinase 4 (PDK4) in the onset and development of Glucocorticoid-induced osteoporosis (GIOP), and seeks potential targets for the treatment of GIOP.

METHODS

Mesenchymal stem cells (MSCs) were treated with osteogenic induction medium. An in vitro osteogenic damage model was established by exposing MSCs to a high concentration (10- 6 M) of dexamethasone (DEX). Osteogenic markers were measured with real-time quantitative polymerase chain reaction, western blot, alkaline phosphatase staining, and Alizarin Red S staining. Ferroptosis markers were assessed through reactive oxygen species (ROS) fluorescent probe, transmission electron microscopy, and measurement of malondialdehyde (MDA). The potential mechanism was investigated using RT-qPCR, western blot, lysosomal probes, molecular docking, and other analytical approaches. The role of PDK4 was validated by using a GIOP rat model, micro-computed tomography and Masson's trichrome staining.

RESULTS

High concentrations (10- 6 M) of DEX inhibited osteogenic differentiation in C3H10T1/2 cells, and PDK4 exhibited the opposite effect. PDK4 partially reversed the osteogenic inhibitory effect of DEX both in vivo and in vitro. DEX caused mitochondrial shrinkage and disappearance of cristae in C3H10T1/2 cells, as well as an increase in total iron, ROS, MDA contents, and the level of ferroptosis key factors. These changes were partially weakened by PDK4. The ferroptosis inhibitor ferrostatin-1 partially blocked the inhibitory effect of DEX, while ferroptosis inducer RSL3 inhibited osteogenic differentiation and weakened the reversal effect of PDK4. DEX reduced the protein level of PDK4, which was partially weakened by Bafilomycin A1. The molecular docking results showed that DEX can directly bind with PDK4.

CONCLUSION

PDK4 can enhance the osteogenic differentiation ability of MSCs and bone mass of GIOP rats. DEX may promote the degradation of PDK4 via lysosome pathway, through which to weaken the osteogenic ability of MSCs by increasing ferroptosis. PDK4 may become a potential target for improving GIOP.

Dissecting the mechanisms of velvet antler extract against diabetic osteoporosis via network pharmacology and proteomics

ETHNOPHARMACOLOGICAL RELEVANCE

Velvet antler (VAE) is a famous traditional Chinese medicine (TCM), which has been used for thousands of years to treat bone-related diseases. Nonetheless, whether VAE has anti-diabetic osteoporosis (DOP) properties remains to be elucidated.

AIM OF THE STUDY

The therapeutic mechanism of VAE on DOP is based on integrated proteomics of network pharmacology strategies to study related targets and pathways.

MATERIALS AND METHODS

Liquid chromatography-mass spectrometry (LC/MS) was used to analyze the main molecular components present in the VAE. The DOP mouse model was created by combining a high-fat diet with streptozotocin (STZ). High glucose (HG) induced MC3T3-E1 cells were used as a cell model to evaluate the therapeutic effect of VAE. The mechanisms of VAE in treating DOP were predicted through proteomics. Molecular docking, molecular dynamics simulations, DARTS and functional experiments were employed to further verify its mechanisms.

RESULTS

Altogether 30 components were identified by LC-MS. In vitro and in vivo results were confirmed that VAE had a protective effect on DOP. Combined with network pharmacology, proteomics and functional experiments revealed that TNF/PI3K-AKT signaling pathway may be the potential biochemical pathway for VAE in treating DOP.

CONCLUSIONS

The innovation of this study was investigating the effectiveness of VAE in treating DOP in vivo and in vitro and suggested that VAE might exert anti-DOP effects through the TNF/PI3K-AKT signaling pathway by network pharmacology and proteomics and found that ATK1 was the core target of VAE, which provided valuable insights for the clinical application of VAE in DOP.

Methylase METTL3 regulates oxidative stress-induced osteoblast apoptosis through Wnt/β-catenin signaling pathway

The latest research shows that the imbalance of reactive oxygen species (ROS) leads to oxidative stress-induced osteoblast apoptosis, which is an important factor in the development of osteoporosis. Methyltransferase like 3 (METTL3) is the most widely known methyltransferase, which has a marked effect on the cells of oxidative stress reaction. However, the precise mechanism through which METTL3 mediates oxidative stress-induced osteoblast apoptosis remains uncleared. An ovariectomized (OVX) rat model was established and histochemical staining were used to evaluate bone mass and the expression of METTL3. The oxidative stress state of bone tissue and the expression of METTL3 were detected by RT-PCR. The reactive oxygen species (ROS) levels were detected by DCFH-DA staining. Cell death and apoptosis were detected by CCK8, Hoechst PI double dyeing and TUNEL staining. The mitochondrial membrane potential was detected by JC-1 fluorescent staining. The expression of N6-methyladenosine, the protein levels of cell apoptosis and Wnt/β-catenin signal were detected by RT-PCR and western blot. We demonstrated that METTL3 was highly expressed in OVX-induced osteoporosis, and it inhibited oxidative stress-induced apoptosis of MC3T3-E1 cells by downregulating the ROS-mediated activation of the Wnt/β-catenin signaling pathway in osteoblasts. In addition, under oxidative stress, ROS accumulation further inhibited METTL3 expression and activated the Wnt/β-catenin signaling pathway, which ultimately led to apoptosis of MC3T3-E1 cells. This study investigated the important role of METTL3 in oxidative stress-induced osteoblast apoptosis. It may be a new therapeutic target for osteoporosis from the perspective of oxidative stress.

Exploring the osteogenic effects of simiao wan through activation of the PI3K/AKT pathway in osteoblasts

ETHNOPHARMACOLOGICAL RELEVANCE

Osteoporosis (OP) is a degenerative bone disease commonly associated with reduced bone density and increased fracture risk.

AIM OF THE STUDY

This study aimed to validate the therapeutic effects of Simiao wan (SMW) on OP and explore the underlying mechanism, particularly focusing on the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway.

MATERIALS AND METHODS

The chemical components of SMW were identified using UPLC-Q-TOF-MS/MS. The obtained compounds were then input into the TCMSP, TargetNet, and SwissTargetPrediction databases to predict potential targets. OP-related targets were collected from the GeneCards and DisGeNET databases, and intersecting targets were identified through a Venn diagram. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on the intersecting targets using the Database for Annotation, Visualization and Integrated Discovery (DAVID). SMW extract was subsequently used to treat osteoblasts in vitro, and its toxicity on osteoblasts was assessed using Cell Counting Kit-8 (CCK-8) and lactate dehydrogenase (LDH) release assays. Osteoblast differentiation and activity were further evaluated using alizarin red staining, alkaline phosphatase staining, and Western blot analyses to validate the activation of network pharmacological signaling pathways.

RESULTS

A total of 121 potential targets were identified for SMW in the treatment of OP, with AKT1 as the primary target. The PI3K/AKT pathway emerged as a key signaling pathway potentially involved in SMW's therapeutic effects o OP. Toxicity assessments showed no significant toxicity of SMW on osteoblasts. Additionally, SMW promoted osteoblast proliferation, alkaline phosphatase activity, calcium nodule deposition, and the expression of osteogenic markers (osteocalcin (OCN), runt-related transcription factor 2 (RunX2), and collagen I), and activated the PI3K/AKT signaling pathway. The PI3K/AKT pathway inhibitor LY294002 partially reversed the SMW-induced mineral deposition and expression of OCN, RunX2, and collagen I.

CONCLUSION

SMW demonstrated effective multi-target and multi-pathway therapeutic potential in the treatment of OP, with a significant impact on the PI3K/AKT signaling pathway.

Single-Cell Landscape of the Cochlea Revealed Cell-Type-Specific Diversification in Hipposideros armiger Based on PacBio Long-Read Sequencing

Echolocation represents one of the most rapid adaptive sensorimotor modulation behaviors observed in mammals, establishing bats as one of the most evolutionarily successful mammals. Bats rely on high-frequency hearing for survival, but our understanding of its cellular molecular basis is scattered and segmented. Herein, we constructed the first single-cell transcriptomic landscape of the cochlea in Hipposideros armiger, a CF-FM bat, using a PacBio-optimized genome and compared it with the results obtained from unoptimized original genomes. Sixteen distinct cell types were distributed across five spatial regions of the cochlea. Notably, through hematoxylin and eosin staining and fluorescence in situ hybridization, we identified new types of spiral ganglion neuron (SGN) cells in the cochlea of H. armiger. These SGN cells are likely critical for auditory perception and may have driven the adaptive evolution of high-frequency hearing in this species. Furthermore, we uncovered the differentiation relationships of among specific cell types, such as the transition from supporting cells to hair cells. Using the cochlear cell atlas as a reference, cell types susceptible to deafness-associated genes (in the human) were also identified. In summary, this study provides novel insights into the cellular and molecular mechanisms underlying the adaptive high-frequency hearing in bats and highlights potential candidate cell types and genes for therapeutic interventions in hearing loss.

Chemokines and PI3K/AKT signaling pathway mediate the spontaneously ruptured hepatocellular carcinoma through the regulation of the cell cycle

BACKGROUND

The incidence of spontaneously ruptured hepatocellular carcinoma (srHCC) has been shown to significantly elevate mortality rates. However, the precise mechanisms underlying srHCC remain poorly understood.

METHODS

Analysis was conducted on the data of 198 hepatocellular carcinoma (HCC) patients to investigate the factors contributing to srHCC. The clinical data of 33 transcriptome HCC patients were served for verification. An in-depth transcriptome analysis was conducted to investigate the distinctions between 26 cases of srHCC and 35 cases of non-ruptured hepatocellular carcinoma (nrHCC). Weighted Gene Co-expression Network Analysis (WGCNA) tool was utilized to develop a gene co-expression network. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathways enrichment, and protein-protein interaction (PPI) network were carried out. The corresponding samples for spontaneously ruptured hepatocellular carcinoma tissue (srHCC-T) and ruptured hepatocellular carcinoma paracancerous tissue (srHCC-P) was selected for verification. Transcriptional data were validated through reverse transcription quantitative polymerase chain reaction (RT-qPCR). Immunofluorescence (IF), immunohistochemistry (IHC) and Western blot were used to detect the protein expression.

RESULTS

Our results showed that white blood cell (WBC) and monocyte levels were significant independent risk factors for srHCC (P < 0.05). There was a strong association between the srHCC-T and the expression of cell cycle-related genes BUB1B and macrophage function-related gene MACRO. Furthermore, chemokines and the PI3K/AKT signaling pathway play a crucial role in regulating the cell cycle process through a complex network of interactions, ultimately impacting the occurrence of srHCC.

CONCLUSIONS

Our study confirms that chemokines and the PI3K/AKT signaling pathway mediate the occurrence of HCC rupture by regulating the cell cycle. We provide a theoretical basis for the clinical treatment of srHCC.

Dexamethasone-Functionalized PLLA Membranes: Effects of Layer-by-Layer Coating and Electrospinning on Osteogenesis

The addition of dexamethasone in membranes for guided bone regeneration is promising due to its dual effect: (1) anti-inflammatory action and (2) induction of osteogenesis in host stem cells. Electrospun fiber coating with dexamethasone using the layer-by-layer (LBL) technique offers an interesting alternative for the gradual release of the drug, aiming for enhanced osteodifferentiation activity. This study aimed to develop synthetic poly-L-lactide (PLLA) membranes with dexamethasone incorporated into the fibers or coated on their surface, and to evaluate the drug release rate, as well as the material's ability to promote proliferation, osteoconduction, and osteodifferentiation of human periodontal ligament stem cells (hPDLSCs). PLLA membranes were produced by electrospinning. Dexamethasone was incorporated using three techniques: (A) electrospinning of a co-solution of PLLA with 2.5 w/w% dexamethasone; (B) deposition of four layers on the PLLA membrane using alternating solutions of chitosan and heparin/dexamethasone; (C) deposition of 10 layers on the PLLA membrane using the same solutions. hPDLSC proliferation was measured via CCK-8 at 1, 7, 14, and 21 days. Cellular differentiation was assessed by alkaline phosphatase activity (7 days) and alizarin red staining (21 days) in clonogenic and osteogenic media (ODM). Data were analyzed using one or two-way ANOVA and Tukey test. Electrospun membranes with dexamethasone and those with 4 layers showed immediate drug release within 24 h, whereas 10 layers exhibited gradual release over 14 days. Cumulative drug release was higher for electrospun membranes at 1 and 7 days, similar to 10 layers at 14 and 21 days. The 4 LBL membrane promoted lower hPDLSC proliferation compared to the 10 LBL and electrospun membranes at 21 days but showed increased extracellular matrix mineralization in osteogenic media. No significant differences in alkaline phosphatase expression were observed between materials. Therefore, the addition of dexamethasone in 10 layers, combined with heparin, enables gradual drug release. However, lower drug release in the first 24 h by four LBL membranes improved the material's osteogenesis properties. None of the materials improved the osteodifferentiation in the clonogenic medium.

Isovitexin targets SIRT3 to prevent steroid-induced osteonecrosis of the femoral head by modulating mitophagy-mediated ferroptosis

The death of osteoblasts induced by glucocorticoid (GC)-mediated oxidative stress plays a crucial role in the development of steroid-induced osteonecrosis of the femoral head (SIONFH). Improving bone formation driven by osteoblasts has shown promising outcomes in the prognosis of SIONFH. Isovitexin has demonstrated antioxidant properties, but its therapeutic effects on GC-induced oxidative stress and SIONFH remain unexplored. In this study, we analyzed clinical samples obtained from SIONFH patients using proteomic and bioinformatic approaches. We found an imbalance in mitochondrial homeostasis and ferroptosis-induced impairment of osteogenic capacity in SIONFH. Subsequently, we investigated the cause-and-effect relationship between mitochondria and ferroptosis, as well as the regulatory role of mitophagy in maintaining mitochondrial homeostasis and controlling ferroptosis. We then identified the critical involvement of SIRT3 in modulating mitochondrial homeostasis and ferroptosis. Furthermore, molecular docking and co-immunoprecipitation confirmed the strong interaction between SIRT3 and BNIP3. Strikingly, restoring SIRT3 expression significantly inhibited pathological mitophagy mediated by the BNIP3/NIX pathway. Additionally, we discovered that Isovitexin, by promoting SIRT3 expression, effectively regulated mitophagy, preserved mitochondrial homeostasis in osteoblasts, suppressed ferroptosis, and restored osteogenic capacity, leading to remarkable improvements in SIONFH. These findings reveal the effects and molecular mechanisms of Isovitexin on SIONFH and highlight the potential of targeting SIRT3 as a promising strategy to suppress mitophagy-mediated ferroptosis in osteoblasts and against SIONFH.

NEDD4's effect on osteoblastogenesis potential of bone mesenchymal stem cells in rats concerned with PI3K/Akt pathway

Neural precursor cell expressed developmentally down-regulated 4 (NEDD4) is an E3 ubiquitin ligase implicated in craniofacial development. Emerging evidence suggests that NEDD4 may down-regulates Akt signaling, a key element of the PI3K/Akt pathway involved in cell differentiation. This study aimed to investigate NEDD4's role in bone mesenchymal stem cells (BMSCs) differentiation and its interaction with the PI3K/Akt pathway. BMSCs were isolated from SD rats, and NEDD4 expression increased during osteogenic differentiation. Silencing NEDD4 with siRNA elevated alkaline phosphatase (ALP), osteocalcin (OCN), Akt, and mTORC1 expression during induction, while subsequent treatment with LY294002 (a broad spectrum PI3K inhibitor) reduced Akt, mTORC1, ALP, and OCN levels. These findings suggest that NEDD4 may inhibit BMSCs differentiation by suppressing the PI3K/Akt pathway during osteogenesis.

Advances in mechanism and management of bone homeostasis in osteonecrosis: a review article from basic to clinical applications

Osteonecrosis, characterized by bone cell death leading to impaired bone recovery, causes challenges in bone homeostasis maintenance. Bone homeostasis relies on the delicate balance between osteoclasts and osteoblasts, encompassing a series of complex and strictly regulated biological functions. Current treatments, including conservative therapies and surgeries, often fall short of expected outcomes, necessitating a reorientation towards more effective therapeutic strategies according to the pathogenesis. In this review, the authors hierarchically outlined risk factors, emerging mechanisms, and last-decade treatment approaches in osteonecrosis. By connecting mechanisms of bone homeostasis, the authors proposed future research directions should be focused on elucidating risk factors and key molecules, performing high-quality clinical trial, updating practice, and accelerating translational potential.

L-carnitine attenuates autophagic flux, apoptosis, and necroptosis in rats with dexamethasone-induced non-alcoholic steatohepatitis

BACKGROUND

UpToDate, no drugs have been approved to treat nonalcoholic steatohepatitis, the advanced stage of the most prevalent liver disease, non-alcoholic fatty liver disease. The present study was conducted to explore the potential influences of L-carnitine on the pathomechanisms of hepatic injury that mediate progression to non-alcoholic steatohepatitis in dexamethasone-toxified rats.

METHODS

Male Wistar rats were allocated as follows: dexamethasone group, rats received dexamethasone (8 mg/kg/day, intraperitoneally) for 6 days; DEXA-LCAR300, DEXA-LCAR500, and DEXA-MET groups, rats administered L-carnitine (300 or 500 mg/kg/day, IP) or metformin (500 mg/kg/day, orally) one week prior to dexamethasone injection (8 mg/kg/day, IP) and other six days alongside dexamethasone administration. Two groups of age-matched normal rats received either the drug vehicle (the control group) or the higher dose of L-carnitine (the drug-control group). At the end of the experiment, sets of biochemical, histological, and immunohistochemical examinations were performed.

RESULTS

L-carnitine (mainly at the dose of 500 mg/kg/day) markedly abolished dexamethasone-induced alterations in glucose tolerance, hepatic histological features, and serum parameters of hepatic function and lipid profile. Moreover, it significantly ameliorated dexamethasone-induced elevations of hepatic oxidative stress, SREBP-1 and p-MLKL protein levels, and nuclear FOXO1, LC3, P62, and caspase-3 immunohistochemical expression. Furthermore, it markedly diminished dexamethasone-induced suppression of hepatic Akt phosphorylation and Bcl2 immunohistochemical expression. The effects of L-carnitine (500 mg/kg/day) were comparable to those of metformin in most assessments and better than its corresponding lower dose.

CONCLUSION

These findings introduce L-carnitine as a potential protective drug that may mitigate the rate of disease progression in non-alcoholic fatty liver disease patients with early stages or those at the highest risks.

Impacts and mechanisms of PM2.5 on bone

Osteoporosis is a metabolic bone disease, which is characterized by a decreased bone mass and deterioration of bone microstructure, resulting in increased bone fragility and a higher risk of fracture. The main pathological process of osteoporosis is the dynamic imbalance between bone absorption and bone formation, which can be caused by various factors such as air pollution. Particulate matter (PM)2.5 refers to the fine particles in the atmosphere, which are small in volume and large in specific surface area. These particles are prone to carrying toxic substances and have negative effects on several extrapulmonary organs, including bones. In this review, we present relevant data from studies, which show that PM2.5 is associated with abnormal bone turnover and osteoporosis. PM2.5 may cause or aggravate bone loss by stimulating an inflammatory response, inducing oxidative damage, reducing estrogen efficiency by competitive binding to estrogen receptors, or endocrine disorder mediated by binding with aromatic hydrocarbon receptors, and affecting the synthesis of vitamin D to reduce calcium absorption. The cellular and molecular mechanisms involved in these processes are also summarized in this review.

Lutein Maintains Bone Mass In Vitro and In Vivo Against Disuse-Induced Bone Loss in Hindlimb-Unloaded Mice

BACKGROUND

Lutein, a carotenoid, exhibits various biological activities such as maintaining the health of the eye, skin, heart, and bone. Recently, we found that lutein has dual roles in suppressing bone resorption and promoting bone formation. In this study, we examined the effects of lutein in a disuse-induced osteoporosis model using hindlimb-unloaded (HLU) mice.

METHODS

Osteoclast differentiation was assessed by coculturing mouse primary osteoblasts and bone marrow cells or culturing a mouse osteoclast precursor cell line. The bone-resorbing activity was determined by mouse calvarial organ cultures. An in situ docking simulation was conducted to reveal the interaction of lutein and IκB kinase (IKK) β protein. HLU mice were fed a 1% lutein-containing diet for two weeks, and the femoral bone mass was measured by μCT.

RESULTS

Osteoclast differentiation is significantly inhibited by lutein, astaxanthin, and β-cryptoxanthin. In contrast, only lutein promoted osteoblastic calcified bone nodule formation. To elucidate the molecular role of lutein, we functionally analyzed the NF-κB complex, a molecule involved in bone metabolism, especially in osteoclasts. Docking simulations showed that lutein binds to IKK, thus inhibiting the activation of NF-κB. In a cell culture analysis, the phosphorylation of p65, the active form of NF-κB in osteoblasts, was suppressed by lutein treatment. In vivo, a μCT analysis of the bone microarchitecture showed that lutein improves several bone parameters while maintaining bone mass.

CONCLUSIONS

Lutein is effective in maintaining bone mass by controlling both bone resorption and formation, which is applied to prevent disuse-induced osteoporosis.

Rehmannioside A promotes the osteoblastic differentiation of MC3T3-E1 cells via the PI3K/AKT signaling pathway and inhibits glucocorticoid-induced bone loss in vivo

Glucocorticoid-induced osteoporosis (GIOP) is a widespread disease characterized by low bone density. There remains a lack of effective means for osteoporosis. Rehmannioside A (ReA), an iridoid glycoside, exhibits various pharmacological activities. This study aimed to explore the role and mechanism of ReA in osteogenic differentiation of osteoblasts. Cell viability, reactive oxygen species (ROS) generation, and cell apoptosis were assessed using corresponding assay kits. Real-time quantitative polymerase chain reaction, Western blotting, and alkaline phosphatase (ALP) staining were performed to evaluate the osteogenic differentiation of MC3T3-E1 cells. Alizarin red S staining was used to assess the mineralization of MC3T3-E1 cells. Protein expression associated with the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway was analyzed using Western blotting. Micro-computed tomography, histopathological, and immunohistochemical analyses were performed to determine the therapeutic effect of ReA on GIOP in vivo.The results showed that ReA promoted the osteogenic differentiation of MC3T3-E1 cells by regulating the PI3K/AKT signaling pathway and protected mice against glucocorticoid-induced bone loss by promoting osteoblast-mediated bone formation in vivo. The findings of the current study revealed that ReA is a potential therapeutic agent for osteoporosis.

The Acute Toxicity and Cardiotoxic Effects of Protocatechuic Aldehyde on Juvenile Zebrafish

Protocatechuic aldehyde (PCA) is a natural phenolic acid compound with pharmacological effects such as anti-oxidative stress, antibacterial, anti-apoptotic, anti-inflammatory, anti-platelet aggregation, and anti-tumor. Despite the favorable therapeutic effects of PCA, it is imperative to recognize that adverse drug reactions can arise even with satisfactory quality assurance measures and during standard clinical application and dosing. Additionally, the acute toxicity and cardiotoxic sequelae of PCA are frequently under reported in the available documentation. To investigate the acute toxicity and cardiotoxic effects of PCA, the present study comprehensively assessed the acute toxicity and cardiotoxic effects of PCA by administering different concentrations of PCA and by monitoring the phenotypic changes in zebrafish, using AB wild-type Tg(cmlc2:EGFP) zebrafish as the experimental model organism. Meanwhile, the target genes of PCA that may cause cardiotoxicity were predicted and validated using a network pharmacology approach. Our findings indicated that PCA exhibited severe acute toxicity and cardiotoxic effects in zebrafish at 70 μg/mL and 80 μg/mL. Furthermore, PIK3CA, PARP1, and GSK3β may be involved in the mechanism of action of the cardiotoxicity-inducing effects of this compound. The present investigation has afforded a deeper insight into the acute toxicity and cardiotoxic impacts of PCA on zebrafish and has established a significant theoretical foundation for the evaluation of toxicity in pharmaceuticals incorporating PCA.

Glutathione inhibits lung cancer development by reducing interleukin-6 expression and reversing the Warburg effect

Reduced glutathione (GSH) is widely used as an antioxidant in clinical practice, but whether GSH affects the development of early lung cancer remains unclear. Herein, we investigated the mechanism underlying the anticancer effect of GSH in patients with pulmonary nodules. Thirty patients with pulmonary nodules were treated with GSH intravenously for 10 days at a dose of 1.8 g/d, followed by oral administration of the drug at a dose of 0.4 g three times daily for 6 months. The results showed that GSH treatment promoted nodule absorption and reduced the IL-6 level in the peripheral blood of the patients. GSH reduced IL-6 expression in inflammatory BEAS-2B and lung cancer cells and inhibited the proliferation of lung cancer cell lines in vitro. In addition, GSH reduced IL-6 expression by decreasing ROS via down-regulating PI3K/AKT/FoxO pathways. Finally, GSH reversed the Warburg effect, restored mitochondrial function, and reduced the IL-6 expression via PI3K/AKT/FoxO pathways. The in vivo experiment confirmed that GSH inhibited lung cancer growth, improved mitochondrial function, and reduced the IL-6 expression by regulating key enzymes via the PI3K/AKT/FoxO pathway. In conclusion, we uncovered that GSH exerts an unprecedentedly potent anti-cancer effect to prevent the transformation of lung nodules to lung cancer by improving the mitochondrial function and suppressing inflammation via PI3K/AKT/FoxO pathway. This investigation innovatively positions GSH as a potentially safe and efficacious old drug with new uses, inhibiting inflammation and early lung cancer. The use of the drug offers a promising preventive strategy when administered during the early stages of lung cancer.

Redox signaling regulates the skeletal tissue development and regeneration

Skeletal tissue development and regeneration in mammals are intricate, multistep, and highly regulated processes. Various signaling pathways have been implicated in the regulation of these processes, including redox. Redox signaling is the signal transduction by electron transfer reactions involving free radicals or related species. Redox homeostasis is essential to cell metabolic states, as the ROS not only regulates cell biological processes but also mediates physiological processes. Following a bone fracture, redox signaling is also triggered to regulate bone healing and regeneration by targeting resident stromal cells, osteoblasts, osteoclasts and endothelial cells. This review will focus on how the redox signaling impact the bone development and bone regeneration.

Fluid shear stress-mediated Piezo1 alleviates osteocyte apoptosis by activating the PI3K/Akt pathway

Glucocorticoid-induced osteoporosis serves as a primary cause for secondary osteoporosis and fragility fractures, representing the most prevalent adverse reaction associated with prolonged glucocorticoid use. In this study, to elucidate the impact and underlying mechanisms of fluid shear stress (FSS)-mediated Piezo1 on dexamethasone (Dex)-induced apoptosis, we respectively applied Dex treatment for 6 h, FSS at 9 dyne/cm2 for 30 min, Yoda1 treatment for 2 h, and Piezo1 siRNA transfection to intervene in MLO-Y4 osteocytes. Western blot analysis was used to assess the expression of Cleaved Caspase-3, Bax, Bcl-2, and proteins associated with the PI3K/Akt pathway. Additionally, qRT-PCR was utilized to quantify the mRNA expression levels of these molecules. Hoechst 33258 staining and flow cytometry were utilized to evaluate the apoptosis levels. The results indicate that FSS at 9 dyne/cm2 for 30 min significantly upregulates Piezo1 in osteocytes. Following Dex-induced apoptosis, the phosphorylation levels of PI3K and Akt are markedly suppressed. FSS-mediated Piezo1 exerts a protective effect against Dex-induced apoptosis by activating the PI3K/Akt pathway. Additionally, downregulating the expression of Piezo1 in osteocytes using siRNA exacerbates Dex-induced apoptosis. To further demonstrate the role of the PI3K/Akt signaling pathway, after intervention with the PI3K pathway inhibitor, the activation of the PI3K/Akt pathway by FSS-mediated Piezo1 in osteocytes was significantly inhibited, reversing the anti-apoptotic effect. This study indicates that under FSS, Piezo1 in MLO-Y4 osteocytes is significantly upregulated, providing protection against Dex-induced apoptosis through the activation of the PI3K/Akt pathway.

The Role of Mitochondrial Permeability Transition in Bone Metabolism, Bone Healing, and Bone Diseases

Bone is a dynamic organ with an active metabolism and high sensitivity to mitochondrial dysfunction. The mitochondrial permeability transition pore (mPTP) is a low-selectivity channel situated in the inner mitochondrial membrane (IMM), permitting the exchange of molecules of up to 1.5 kDa in and out of the IMM. Recent studies have highlighted the critical role of the mPTP in bone tissue, but there is currently a lack of reviews concerning this topic. This review discusses the structure and function of the mPTP and its impact on bone-related cells and bone-related pathological states. The mPTP activity is reduced during the osteogenic differentiation of mesenchymal stem cells (MSCs), while its desensitisation may underlie the mechanism of enhanced resistance to apoptosis in neoplastic osteoblastic cells. mPTP over-opening triggers mitochondrial swelling, regulated cell death, and inflammatory response. In particular, mPTP over-opening is involved in dexamethasone-induced osteoblast dysfunction and bisphosphonate-induced osteoclast apoptosis. In vivo, the mPTP plays a significant role in maintaining bone homeostasis, with many bone disorders linked to its excessive opening. Genetic deletion or pharmacological inhibition of the over-opening of mPTP has shown potential in enhancing bone injury recovery and alleviating bone diseases. Here, we review the findings on the relationship of the mPTP and bone at both the cellular and disease levels, highlighting novel avenues for pharmacological approaches targeting mitochondrial function to promote bone healing and manage bone-related disorders.

MAGL blockade alleviates steroid-induced femoral head osteonecrosis by reprogramming BMSC fate in rat

The leading cause of steroid-induced femoral head osteonecrosis (ONFH) is the imbalance of bone homeostasis. Bone marrow-derived mesenchymal stem cell (BMSC) differentiation and fate are closely associated with bone homeostasis imbalance. Blocking monoacylglycerol lipase (MAGL) could effectively ameliorate ONFH by mitigating oxidative stress and apoptosis in BMSCs induced by glucocorticoids (GC). Nevertheless, whether MAGL inhibition can modulate the balance during BMSC differentiation, and therefore improve ONFH, remains elusive. Our study indicates that MAGL inhibition can effectively rescue the enhanced BMSC adipogenic differentiation caused by GC and promote their differentiation toward osteogenic lineages. Cannabinoid receptor 2 (CB2) is the direct downstream target of MAGL in BMSCs, rather than cannabinoid receptor 1(CB1). Using RNA sequencing analyses and a series of in vitro experiments, we confirm that the MAGL blockade-induced enhancement of BMSC osteogenic differentiation is primarily mediated by the phosphoinositide 3-kinases (PI3K)/ the serine/threonine kinase (AKT)/ (glycogen synthase kinase-3 beta) GSK3β pathway. Additionally, MAGL blockade can also reduce GC-induced bone resorption by directly suppressing osteoclastogenesis and indirectly reducing the expression of receptor activator of nuclear factor kappa-Β ligand (RANKL) in BMSCs. Thus, our study proposes that the therapeutic effect of MAGL blockade on ONFH is partly mediated by restoring the balance of bone homeostasis and MAGL may be an effective therapeutic target for ONFH.

Single-cell and bulk RNA-sequencing reveal SPP1 and CXCL12 as cell-to-cell communication markers to predict prognosis in lung adenocarcinoma

Lung adenocarcinoma (LUAD) generally presents as an immunosuppressive microenvironment. The characteristics of cell-to-cell communication in the LUAD microenvironment has been unclear. In this study, the LUAD bulk RNA-seq data and single-cell RNA-seq data were retrieved from public dataset. Differential expression genes (DEGs) between LUAD tumor and adjacent non-tumor tissues were calculated by limma algorithm, and then detected by PPI, KEGG, and GO analysis. Cell-cell interactions were explored using the single-cell RNA-seq data. Finally, the first 15 CytoHubba genes were used to establish related pathways and these pathways were used to characterize the immune-related ligands and their receptors in LUAD. Our analyses showed that monocytes or macrophages interact with tissue stem cells and NK cells via SPP1 signaling pathway and tissue stem cells interact with T and B cells via CXCL signaling pathway in different states. Hub genes of SPP1 participated in SPP1 signaling pathway, which was negatively correlated with CD4+ T cell and CD8+ T cell. The expression of SPP1 in LUAD tumor tissues was negatively correlated with the prognosis. While CXCL12 participated in CXCL signaling pathway, which was positively correlated with CD4+ T cell and CD8+ T cell. The role of CXCL12 in LUAD tumor tissues exhibits an opposite effect to that of SPP1. This study reveals that tumor-associated monocytes or macrophages may affect tumor progression. Moreover, the SPP1 and CXCL12 may be the critic genes of cell-to-cell communication in LUAD, and targeting these pathways may provide a new molecular mechanism for the treatment of LUAD.

Design, synthesis and biological evaluation of novel naphthoquinothiazole derivatives as potent antitumor agents through inhibiting STAT3

The signal transducer and activator of transcription 3 (STAT3) has been established as a crucial drug target in the development of antitumor agents. In this study, a series of 21 derivatives of the STAT3 inhibitor napabucasin were designed and synthesized. Through preliminary screening against tumor cell lines, SZ6 emerged as the most potent compound with half maximal inhibitory concentration (IC50) values of 46.3 nM, 66.4 nM, and 53.8 nM against HCT116, HepG2, and Hela cells respectively. Furthermore, SZ6 effectively suppressed tumor invasion and migration in HCT116 cell assays by inducing S-phase arrest and apoptosis through inhibition of Protein Kinase B (PKB/AKT) activity and induction of reactive oxygen species (ROS). The mechanism underlying SZ6's action involves inhibition of STAT3 phosphorylation, which was confirmed by western blotting analysis. Additionally, surface plasmon resonance (SPR) and cellular thermal shift assay (CETSA) demonstrated direct binding between SZ6 and STAT3. Notably, in vivo studies revealed that SZ6 significantly inhibited tumor growth without any observed organ toxicity. Collectively, these findings identify SZ6 as a promising STAT3 inhibitor for colorectal cancer treatment.

Associations of oxidative balance score with lumbar spine osteopenia in 20-40 years adults: NHANES 2011-2018

PURPOSE

Current research suggests that oxidative stress may decrease bone mineral density (BMD) by disrupting bone metabolism balance. However, no study investigated the relationship between systemic oxidative stress status and adult BMD. This study aims to investigate whether oxidative balance score (OBS) is associated with BMD in adults under 40.

METHODS

3963 participants were selected from the National Health and Nutrition Survey (NHANES) from 2011 to 2018. OBS is scored based on 20 dietary and lifestyle factors. Weighted multiple logistic regression and restricted cubic splines were used to assess the correlation between OBS and osteopenia.

RESULTS

After adjusting for confounding factors, the weighted logistic regression results showed that compared with the first tertile of OBS, the highest tertile had a 38% (OR: 0.62, 95% CI: 0.47-0.82) lower risk of osteopenia. The restrictive cubic spline curve indicates a significant nonlinear correlation between OBS and the risk of osteopenia.

CONCLUSION

The research findings emphasize the relationship between OBS and the risk of osteopenia in young adults. Adopting an antioxidant diet and lifestyle may help young adults to maintain bone mass.

NOX4-reactive oxygen species axis: critical regulators of bone health and metabolism

Bone marrow stromal cells (BMSCs) play a significant role in bone metabolism as they can differentiate into osteoblasts, bone marrow adipocytes (BMAds), and chondrocytes. BMSCs chronically exposed to nutrient overload undergo adipogenic programming, resulting in bone marrow adipose tissue (BMAT) formation. BMAT is a fat depot transcriptionally, metabolically, and morphologically distinct from peripheral adipose depots. Reactive oxygen species (ROS) are elevated in obesity and serve as important signals directing BMSC fate. ROS produced by the NADPH oxidase (NOX) family of enzymes, such as NOX4, may be responsible for driving BMSC adipogenesis at the expense of osteogenic differentiation. The dual nature of ROS as both cellular signaling mediators and contributors to oxidative stress complicates their effects on bone metabolism. This review discusses the complex interplay between ROS and BMSC differentiation in the context of metabolic bone diseases.Special attention is paid to the role of NOX4-ROS in regulating cellular processes within the bone marrow microenvironment and potential target in metabolic bone diseases.

The potential therapeutic role of curcumin in osteoporosis treatment: based on multiple signaling pathways

Osteoporosis is a common chronic metabolic bone disease caused by disturbances in normal bone metabolism and an imbalance between osteoblasts and osteoclasts. Osteoporosis is characterized by a decrease in bone mass and bone density, leading to increased bone fragility. Osteoporosis is usually treated with medications and surgical methods, but these methods often produce certain side effects. Therefore, the use of traditional herbal ingredients for the treatment of osteoporosis has become a focus of attention and a hot topic in recent years. Curcumin, widely distributed among herbs such as turmeric, tulip, and curcuma longa, contains phenolic, terpenoid, and flavonoid components. Modern pharmacological studies have confirmed that curcumin has a variety of functions including antioxidant and anti-inflammatory properties. In addition, curcumin positively regulates the differentiation and promotes the proliferation of osteoblasts, which play a crucial role in bone formation. Multiple studies have shown that curcumin is effective in the treatment of osteoporosis as it interacts with a variety of signaling pathway targets, thereby interfering with the formation of osteoblasts and osteoclasts and regulating the development of osteoporosis. This review summarized the key signaling pathways and their mechanisms of action of curcumin in the prevention and treatment of osteoporosis and analyzed their characteristics and their relationship with osteoporosis and curcumin. This not only proves the medicinal value of curcumin as a traditional herbal ingredient but also further elucidates the molecular mechanism of curcumin's anti-osteoporosis effect, providing new perspectives for the prevention and treatment of osteoporosis through multiple pathways.

The role of N-acetylcysteine in osteogenic microenvironment for bone tissue engineering

Bone defect is a common clinical symptom which can arise from various causes. Currently, bone tissue engineering has demonstrated positive therapeutic effects for bone defect repair by using seeding cells such as mesenchymal stem cells and precursor cells. N-acetylcysteine (NAC) is a stable, safe and highly bioavailable antioxidant that shows promising prospects in bone tissue engineering due to the ability to attenuate oxidative stress and enhance the osteogenic potential and immune regulatory function of cells. This review systematically introduces the antioxidant mechanism of NAC, analyzes the advancements in NAC-related research involving mesenchymal stem cells, precursor cells, innate immune cells and animal models, discusses its function using the classic oral microenvironment as an example, and places particular emphasis on the innovative applications of NAC-modified tissue engineering biomaterials. Finally, current limitations and future prospects are proposed, with the aim of providing inspiration for targeted readers in the field.

TXNIP mediated by EZH2 regulated osteogenic differentiation in hBmscs and MC3T3-E1 cells through the modulation of oxidative stress and PI3K/AKT/Nrf2 pathway

BACKGROUND

Previous research has identified a significant role of Thioredoxin-interacting protein (TXNIP) in bone loss. The purpose of this investigation was to assess the role and the underlying molecular mechanisms of TXNIP in the osteogenic differentiation of human bone marrow stromal cells (hBMSCs) and pre-osteoblast MC3T3-E1 cells.

METHODS

Human bone marrow stem cells (hBMSCs) and MC3T3-E1 cells were used to induce osteogenic differentiation. The expression of genes and proteins was assessed using RT-qPCR and western blot, respectively. ChIP assay was used to validate the interaction between genes. The osteogenic differentiation ability of cells was reflected using ALP staining and detection of ALP activity. The mineralization ability of cells was assessed using ARS staining. DCFCA staining was employed to evaluate the intracellular ROS level.

RESULTS

Initially, downregulation of TXNIP and upregulation of EZH2 were observed during osteogenesis in hBMSCs and MC3T3-E1 cells. Additionally, it was discovered that EZH2 negatively regulates TXNIP expression in these cells. Furthermore, experiments indicated that the knockdown of TXNIP stimulated the activation of the PI3K/AKT/Nrf2 signaling pathway in hBMSCs and MC3T3- E1 cells, thus inhibiting the production of reactive oxygen species (ROS). Further functional experiments revealed that overexpression of TXNIP inhibited the osteogenic differentiation in hBMSCs and MC3T3-E1 cells by enhancing ROS produc-tion. On the other hand, knockdown of TXNIP promoted the osteogenic differentiation capacity of hBMSCs and MC3T3-E1 cells through the activation of the PI3K/AKT/Nrf2 pathway.

CONCLUSION

In conclusion, this study demonstrated that TXNIP expression, under the regulation of EZH2, plays a crucial role in the osteogenic differentiation of hBMSCs and MC3T3-E1 cells by regulating ROS production and the PI3K/AKT/Nrf2 pathway.

Eco-endocrinological dynamics: Unraveling dexamethasone's influence on the interrenal axis in juvenile carp Cyprinus carpio

This study delves into the eco-endocrinological dynamics concerning the impact of dexamethasone (DXE) on the interrenal axis in juvenile carp, Cyprinus carpio. Through a comprehensive analysis, we investigated the effects of DXE exposure on oxidative stress, biochemical biomarkers, gene expression, and bioaccumulation within the interrenal axis. Results revealed a concentration-dependent escalation of cellular oxidation biomarkers, including 1) hydroperoxides content (HPC), 2) lipid peroxidation level (LPX), and 3) protein carbonyl content (PCC), indicative of heightened oxidative stress. Concurrently, the activity of critical antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT), significantly increased, underscoring the organism's response to oxidative insult. Notable alterations were observed in biochemical biomarkers, particularly Gamma-glutamyl-transpeptidase (GGT) and alkaline phosphatase (ALP) activity, with GGT displaying a significant decrease with increasing DXE concentrations. Gene expression analysis revealed a significant upregulation of stress and inflammation response genes, as well as those associated with sensitivity to superoxide ion presence and calcium signaling, in response to DXE exposure. Furthermore, DXE demonstrated a concentration-dependent presence in interrenal tissue, with consistent bioconcentration factors observed across all concentrations tested. These findings shed light on the physiological and molecular responses of juvenile carp to DXE exposure, emphasizing the potential ecological implications of DXE contamination in aquatic environments. Understanding these dynamics is crucial for assessing the environmental impact of glucocorticoid pollutants and developing effective management strategies to mitigate their adverse effects on aquatic ecosystems.

Advances in the Pathogenesis of Steroid-Associated Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is a refractory orthopedic condition characterized by bone cell ischemia, necrosis, bone trabecular fracture, and clinical symptoms such as pain, femoral head collapse, and joint dysfunction that can lead to disability. The disability rate of ONFH is very high, which imposes a significant economic burden on both families and society. Steroid-associated osteonecrosis of the femoral head (SANFH) is the most common type of ONFH. However, the pathogenesis of SANFH remains unclear, and it is an urgent challenge for orthopedic surgeons to explore it. In this paper, the pathogenesis of SANFH and its related signaling pathways were briefly reviewed to enhance comprehension of the pathogenesis and prevention of SANFH.

TRIM21 silencing inhibits the apoptosis and expedites the osteogenic differentiation of dexamethasone‑induced MC3T3‑E1 cells by activating the Keap1/Nrf2 pathway

Steroid-induced osteonecrosis of the femoral head (ONFH) is a serious complication caused by long-term or excessive use of glucocorticoids. The present study aimed to ascertain the effects of tripartite motif-containing protein 21 (TRIM21) on the process of steroid-induced ONFH and its hidden action mechanism. TRIM21 expression in dexamethasone (Dex)-treated mouse MC3T3-E1 preosteoblast cells was examined using reverse transcription-quantitative PCR and western blotting. The Cell Counting Kit-8 (CCK-8) method and lactate dehydrogenase release assay were used to respectively measure cell viability and injury. Flow cytometry analysis was used to assay cell apoptosis. Caspase 3 activity was evaluated using a specific assay, while alkaline phosphatase and Alizarin red S staining were used to evaluate osteogenesis. 2,7-dichloro-dihydrofluorescein diacetate fluorescence probe was used to estimate reactive oxygen species generation. Specific assay kits were used to appraise oxidative stress levels. In addition, the expression of apoptosis-, osteogenic differentiation- and Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling-associated proteins was assessed using western blotting. In Nrf2 inhibitor (ML385)-pretreated MC3T3-E1 cells exposed to Dex, cell apoptosis, osteogenesis and oxidative stress were detected again as aforementioned. Results revealed that TRIM21 expression was raised in Dex-induced MC3T3-E1 cells and TRIM21 deletion improved the viability and osteogenic differentiation, whereas it hampered the oxidative stress and apoptosis in MC3T3-E1 cells with Dex induction. In addition, silencing of TRIM21 activated Keap1/Nrf2 signaling. Moreover, ML385 partially abrogated the effects of TRIM21 depletion on the oxidative stress, apoptosis and osteogenic differentiation in MC3T3-E1 cells exposed to Dex. In conclusion, TRIM21 silencing might activate Keap1/Nrf2 signaling to protect against steroid-induced ONFH.

Asiatic acid prevents glucocorticoid-induced femoral head osteonecrosis via PI3K/AKT pathway

Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) represents a predominant etiology of non-traumatic osteonecrosis, imposing substantial pain, restricting hip mobility, and diminishing overall quality of life for affected individuals. Centella asiatica (L.) Urb. (CA), an herbal remedy deeply rooted in traditional oriental medicine, has exhibited noteworthy therapeutic efficacy in addressing inflammation and facilitating wound healing. Drawing from CA's historical applications, its anti-inflammatory, anti-apoptotic, and antioxidant attributes may hold promise for managing GIONFH. Asiatic acid (AA), a primary constituent of CA, has been substantiated as a key contributor to its anti-apoptotic, antioxidant, and anti-inflammatory capabilities, showcasing a close association with orthopedic conditions. For the investigation of whether AA could alleviate GIONFH through suppressing oxidative stress, apoptosis, and to delve into its potential cellular and molecular mechanisms, the connection between AA and disease was analyzed through network pharmacology. DEX-induced apoptosis in rat osteoblasts and GIONFH in rat models, got utilized for the verification in vitro/vivo, on underlying mechanism of AA in GIONFH. Network pharmacology analysis reveals a robust correlation between AA and GIONFH in multiple target genes. AA has demonstrated the inhibition of DEX-induced osteoblast apoptosis by modulating apoptotic factors like BAX, BCL-2, Cleaved-caspase3, and cleaved-caspase9. Furthermore, it effectively diminishes the ROS overexpression and regulates oxidative stress through mitochondrial pathway. Mechanistic insights suggest that AA's therapeutic effects involve phosphatidylinositol 3-kinase/Protein kinase B (PI3K/AKT) pathway activation. Additionally, AA has exhibited its potential to ameliorate GIONFH progression in rat models. Our findings revealed that AA mitigated DEX-induced osteoblast apoptosis and oxidative stress through triggering PI3K/AKT pathway. Also, AA can effectively thwart GIONFH occurrence and development in rats.

Echinacoside alleviates glucocorticoid induce osteonecrosis of femoral head in rats through PI3K/AKT/FOXO1 pathway

Steroid-induced osteonecrosis of the femoral head (SONFH), caused by glucocorticoid (GC) administration, is known to exhibit a high incidence worldwide. Although osteoblast apoptosis has been reported as an important cytological basis of SONFH, the precise mechanism remains elusive. Echinacoside (Ech), a natural phenylethanoid glycoside, exerts multiple beneficial effects, such as facilitation of cell proliferation and anti-inflammatory and anticancer activities. Herein, we aimed to explore the regulatory mechanism underlying glucocorticoid-induced osteoblast apoptosis and determine the protective efficacy of Ech against SONFH. We comprehensively surveyed multiple public databases to identify SONFH-related genes. Using bioinformatics analysis, we identified that the PI3K/AKT/FOXO1 signaling pathway was most strongly associated with SONFH. We examined the protective effect of Ech against SONFH using in vivo and in vitro experiments. Specifically, dexamethasone (Dex) decreased p-PI3K and p-AKT levels, which were reversed following Ech addition. Validation of the PI3K inhibitor (LY294002) and molecular docking of Ech and PI3K/AKT further indicated that Ech could directly enhance PI3K/AKT activity to alleviate Dex-induced inhibition. Interestingly, Dex upregulated the expression of FOXO1, Bax, cleaved-caspase-9, and cleaved-caspase-3 and enhanced MC3T3-E1 apoptosis; application of Ech and siRNA-FOXO1 reversed these effects. In vitro, Ech decreased the number of empty osteocytic lacunae, reduced TUNEL and FOXO1 positive cells, and improved bone microarchitecture. Our results provide robust evidence that PI3K/AKT/FOXO1 plays a crucial role in the development of SONFH. Moreover, Ech may be a promising candidate drug for the treatment of SONFH.

PDGFBB facilitates tumorigenesis and malignancy of lung adenocarcinoma associated with PI3K-AKT/MAPK signaling

Lung adenocarcinoma (LUAD) remains one of the most aggressive tumors and the efficacy of conventional treatment has been bleak. Nowadays, gene-targeted therapy has become a new favorite in tumor therapy. Herein, we investigated the effect of platelet derived growth factor BB (PDGFBB) on LUAD. Firstly, PDGFBB was upregulated in LUAD patients and closely linked with poor survival. Furthermore, the expression of PDGFBB and PDGFRα/β in LUAD cells was higher than that in normal lung cells. By loss-of-function with herpes simplex virus (HSV)-PDGFi-shRNA, we found that PDGFBB knockdown caused a significant decrease in proliferation and migration, but evoked apoptosis of LUAD cells in vitro. Conversely, exogenous PDGFBB held adverse effect. Additionally, A549 cells with PDGFBB knockdown had a low probability of tumorigenesis in vivo. Moreover, PDGFBB knockdown restrained the growth of xenografts derived from normal A549 cells. Mechanistically, PDGFBB knockdown suppressed PI3K/AKT and Ras/MAPK signaling, while PDGFBB was the opposite. Therefore, we concluded that PDGFBB might facilitate the tumorigenesis and malignancy of LUAD through its functional downstream nodes-PI3K/AKT and Ras/MAPK signaling, which supported that PDGFBB could serve as a rational therapeutic target for LUAD.

Neutrophil Function Conversion Driven by Immune Switchpoint Regulator against Diabetes-Related Biofilm Infections

Reinforced biofilm structures and dysfunctional neutrophils induced by excessive oxidative stress contribute to the refractoriness of diabetes-related biofilm infections (DRBIs). Herein, in contrast to traditional antibacterial therapies, an immune switchpoint-driven neutrophil immune function conversion strategy based on a deoxyribonuclease I loaded vanadium carbide MXene (DNase-I@V2 C) nanoregulator is proposed to treat DRBIs via biofilm lysis and redirecting neutrophil functions from NETosis to phagocytosis in diabetes. Owing to its intrinsic superoxide dismutase/catalase-like activities, DNase-I@V2 C effectively scavenges reactive oxygen species (ROS) in a high oxidative stress microenvironment to maintain the biological activity of DNase-I. By increasing the depth of biofilm penetration of DNase-I, DNase-I@V2 C thoroughly degrades extracellular DNA and neutrophil extracellular traps (NETs) in extracellular polymeric substances, thus breaking the physical barrier of biofilms. More importantly, as an immune switchpoint regulator, DNase-I@V2 C can skew neutrophil functions from NETosis toward phagocytosis by intercepting ROS-NE/MPO-PAD4 and activating ROS-PI3K-AKT-mTOR pathways in diabetic microenvironment, thereby eliminating biofilm infections. Biofilm lysis and synergistic neutrophil function conversion exert favorable therapeutic effects on biofilm infections in vitro and in vivo. This study serves as a proof-of-principle demonstration of effectively achieving DRBIs with high therapeutic efficacy by regulating immune switchpoint to reverse neutrophil functions.

Biomimetic cryogel promotes the repair of osteoporotic bone defects through altering the ROS niche via down-regulating the ROMO1

Osteoporosis is a systemic bone disease that is prone to fractures due to decreased bone density and bone quality, and delayed union or nonunion often occurs in osteoporotic fractures. Therefore, it is particularly important to develop tissue engineering materials to promote osteoporotic fracture healing. In this study, a series of biomimetic cryogels prepared from the decellularized extracellular matrix (dECM), methacrylate gelatin (GelMA), and carboxymethyl chitosan (CMCS) via unidirectional freezing, photo- and genipin crosslinking were applied for the regeneration of osteoporotic fractures. Specifically, dECM extracted from normal or osteoporotic rats was applied for the preparation of the cryogels, named as GC-Normal dECM or GC-OVX dECM, respectively. It was verified that the GC-Normal dECM demonstrated superior performance in promoting the proliferation of BMSCs isolated from osteoporotic rats (OVX-BMSCs), and the differentiation of OVX-BMSCs into osteoblasts both in vitro and in vivo. RNA sequencing and further verifications confirmed that GC-Normal dECM cryogel could scavenge the intracellular reactive oxygen species (ROS) in OVX-BMSCs to accelerate the regeneration of osteoporotic fracture by down-regulating the reactive oxygen species modulator 1 (Romo1). The results indicated that by regulating the ROS niche of OVX-BMSCs, biomimetic the GC-Normal dECM cryogel was expected to be a clinical candidate for repairing osteoporotic bone defects.

Dexamethasone improves thymoma-associated myasthenia gravis via the AKT-mTOR pathway

Clinically, thymoma patients are often complicated with myasthenia gravis (MG). Dexamethasone, a glucocorticoid with anti-inflammatory effects, could be used as an immunosuppressant for thymoma-associated MG, but the mechanism of action remains to be explored. In this study, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, weighted gene co-expression network analysis (WGCNA) of potential targets was performed by screening the intersection targets of dexamethasone and thymoma-associated MG from the database. Furthermore, the key targets and core active components were identified by topological analysis of the protein-protein interaction (PPI) network. Molecular docking technology was applied to screen the complexes with stable binding of dexamethasone and core targets. Patients with thymoma were divided into two groups according to whether they received dexamethasone before operation, and immunohistochemistry and western blot were used to verify the selected target of dexamethasone in treating thymoma-associated MG. The results showed that the action pathway of dexamethasone on the disease was closely enriched to phosphatidylinositol 3-kinase (PI3K)-protein kinase B (PKB/AKT), mammalian target of rapamycin (mTOR) signaling pathways. The expressions of AKT1 and its downstream molecule mTOR in the thymoma microenvironment of thymoma-associated MG patients who did not receive dexamethasone before operation were higher than those in the group receiving dexamethasone before operation. This study demonstrates that dexamethasone can promote apoptosis through the AKT-mTOR pathway for the treatment of thymoma-associated MG, as validated by network pharmacology predictions and clinical specimen experiments, and can be verified by large-scale clinical trials in the future. This study also provides theoretical support and new research perspectives for this disease.

Morroniside-mediated mitigation of stem cell and endothelial cell dysfunction for the therapy of glucocorticoid-induced osteonecrosis of the femoral head

BACKGROUND

Prolonged use of glucocorticoids (GCs) potentially lead to a condition known as GCs-induced osteonecrosis of the femoral head (GIONFH). The primary mechanisms underlying this phenomenon lies in stem cells and endothelial cells dysfunctions. Morroniside, an iridoid glycoside sourced from Cornus officinalis, possesses numerous biological capabilities, including combating oxidative stress, preventing apoptosis, opposing ischemic effects, and promoting the regeneration of bone tissue.

PURPOSE

This study aimed to analyze the impact of Morroniside on Dexamethasone (DEX)-induced dysfunction in stem cells and endothelial cells, and its potential as a therapeutic agent for GIONFH in rat models.

METHODS

ROS assay, JC-1 assay, and TUNEL assay were used to detect oxidative stress and apoptosis levels in vitro. For the evaluation of the osteogenic capability of bone marrow-derived mesenchymal stem cells, we employed ALP and ARS staining. Additionally, the angiogenic ability of endothelial cells was assessed using tube formation assay and migration assay. Microcomputed tomography analysis, hematoxylin-eosin staining, and immunohistochemical staining were utilized to evaluate the in vivo therapeutic efficacy of Morroniside.

RESULTS

Morroniside mitigates DEX-induced excessive ROS expression and cell apoptosis, effectively reducing oxidative stress and alleviating cell death. In terms of osteogenesis, Morroniside reverses DEX-induced osteogenic impairment, as evidenced by enhanced ALP and ARS staining, as well as increased osteogenic protein expression. In angiogenesis, Morroniside counteracts DEX-induced vascular dysfunction, demonstrated by an increase in tube-like structures in tube formation assays, a rise in the number of migrating cells, and elevated levels of angiogenic proteins. In vivo, our results further indicate that Morroniside alleviates the progression of GIONFH.

CONCLUSION

The experimental findings suggest that Morroniside concurrently mitigates stem cell and endothelial cell dysfunction through the PI3K/AKT signaling pathway both in vitro and in vivo. These outcomes suggest that Morroniside serves as a potential therapeutic agent for GIONFH.

Differential Effect of 4H-Benzo[d] [1, 3]oxazines on the Proliferation of Breast Cancer Cell Lines

BACKGROUND

A family of 4H-benzo[d][1,3]oxazines were obtained from a group of N-(2-alkynyl)aryl benzamides precursors via gold(I) catalysed chemoselective 6-exo-dig C-O cyclization.

METHOD

The precursors and oxazines obtained were studied in breast cancer cell lines MCF-7, CAMA-1, HCC1954 and SKBR-3 with differential biological activity showing various degrees of inhibition with a notable effect for those that had an aryl substituted at C-2 of the molecules. 4H-benzo[d][1,3]oxazines showed an IC50 rating from 0.30 to 157.4 µM in MCF-7, 0.16 to 139 in CAMA-1, 0.09 to 93.08 in SKBR-3, and 0.51 to 157.2 in HCC1954 cells.

RESULTS

We observed that etoposide is similar to benzoxazines while taxol effect is more potent. Four cell lines responded to benzoxazines while SKBR-3 cell line responded to precursors and benzoxazines. Compounds 16, 24, 25 and 26 have the potent effect in cell proliferation inhibition in the 4 cell lines tested and correlated with oxidant activity suggesting a possible mechanism by ROS generation.

CONCLUSION

These compounds represent possible drug candidates for the treatment of breast cancer. However, further trials are needed to elucidate its full effect on cellular and molecular features of cancer.

Taxifolin-mediated Nrf2 activation ameliorates oxidative stress and apoptosis for the treatment of glucocorticoid-induced osteonecrosis of the femoral head

Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is the main complication secondary to long-term or excessive use of glucocorticoids (GCs). Taxifolin (TAX) is a natural antioxidant with various pharmacological effects, such as antioxidative stress and antiapoptotic properties. The purpose of this study was to explore whether TAX could regulate oxidative stress and apoptosis in GIONFH by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. We conducted qRT-PCR, Western blotting, TUNEL assays, flow cytometry, and other experiments in vitro. Microcomputed tomography analysis, hematoxylin-eosin staining, and immunohistochemical staining were performed to determine the therapeutic effect of TAX in vivo. TAX mitigated the overexpression of ROS and NOX gene expression induced by DEX, effectively reducing oxidative stress. Additionally, TAX could alleviate DEX-induced osteoblast apoptosis, as evidenced by qRT-PCR, Western blotting, and other experimental techniques. Our in vivo studies further demonstrated that TAX mitigates the progression of GIONFH in rats by combating oxidative stress and apoptosis. Mechanistic exploration revealed that TAX thwarts the progression of GIONFH through the activation of the Nrf2 pathway. Overall, our research herein reports that TAX-mediated Nrf2 activation ameliorates oxidative stress and apoptosis for the treatment of GIONFH.