Activating Wnt/β-catenin signaling by autophagic degradation of APC contributes to the osteoblast differentiation effect of soy isoflavone on osteoporotic mesenchymal stem cells

Interplay between Wnt signaling molecules and exosomal miRNAs in breast cancer (Review)

Breast cancer (BC) is the most common malignancy in women worldwide. Wnt signaling is involved in tumorigenesis and cancer progression, and is closely associated with the characteristics of BC. Variation in the expression of exosomal microRNAs (miRNAs) modulates key cancer phenotypes, such as cellular proliferation, epithelial‑mesenchymal transition, metastatic potential, immune evasion and treatment resistance. The present review aimed to discuss the importance of Wnt signaling and exosomal miRNAs in regulating the occurrence and development of BC. In addition, the present review determined the crosstalk between Wnt signaling and exosomal miRNAs, and highlighted potential diagnostic biomarkers and therapeutic targets.

Cell signaling and transcriptional regulation of osteoblast lineage commitment, differentiation, bone formation, and homeostasis

The initiation of osteogenesis primarily occurs as mesenchymal stem cells undergo differentiation into osteoblasts. This differentiation process plays a crucial role in bone formation and homeostasis and is regulated by two intricate processes: cell signal transduction and transcriptional gene expression. Various essential cell signaling pathways, including Wnt, BMP, TGF-β, Hedgehog, PTH, FGF, Ephrin, Notch, Hippo, and Piezo1/2, play a critical role in facilitating osteoblast differentiation, bone formation, and bone homeostasis. Key transcriptional factors in this differentiation process include Runx2, Cbfβ, Runx1, Osterix, ATF4, SATB2, and TAZ/YAP. Furthermore, a diverse array of epigenetic factors also plays critical roles in osteoblast differentiation, bone formation, and homeostasis at the transcriptional level. This review provides an overview of the latest developments and current comprehension concerning the pathways of cell signaling, regulation of hormones, and transcriptional regulation of genes involved in the commitment and differentiation of osteoblast lineage, as well as in bone formation and maintenance of homeostasis. The paper also reviews epigenetic regulation of osteoblast differentiation via mechanisms, such as histone and DNA modifications. Additionally, we summarize the latest developments in osteoblast biology spurred by recent advancements in various modern technologies and bioinformatics. By synthesizing these insights into a comprehensive understanding of osteoblast differentiation, this review provides further clarification of the mechanisms underlying osteoblast lineage commitment, differentiation, and bone formation, and highlights potential new therapeutic applications for the treatment of bone diseases.

The association between remnant cholesterol and bone mineral density in US adults: the National Health and Nutrition Examination Survey (NHANES) 2013-2018

BACKGROUND

Previous evidence showed a possible link of dyslipidemia with bone health. Nevertheless, the correlation of remnant cholesterol (RC) with bone mineral density (BMD) has yet to be well investigated. This study investigated the association of RC with total spine BMD in general Americans.

METHODS

This study explored the relationship of RC with total spine BMD in subjects aged ≥ 20 years from the National Health and Nutrition Examination Survey (NHANES) 2013-2018. After adjusting for covariates, multivariate linear regression and stratified analyses were conducted to determine the correlation of serum RC with total spine BMD in adult Americans. Restricted cubic spline (RCS) was applied to examine the nonlinear association of serum RC with total spine BMD.

RESULTS

This study included 3815 individuals ≥ 20 years old, 1905 (49.93%) of whom were men and 1910 (50.07%) of whom were women. After adjusting for all covariates, the results showed a negative relationship of serum RC with total spine BMD (β= -0.024, 95% CI: -0.039, -0.010). The interaction tests of age, sex, race, and BMI showed no statistically significant effects on the association. The RCS also indicated a negative linear correlation of serum RC with total spine BMD (nonlinear P = 0.068, overall P < 0.001). Moreover, RC had a stronger effect on total spine BMD than total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C).

CONCLUSIONS

This study found that serum RC was negatively related to total spine BMD in U.S. adults. These findings emphasized the important role of RC in bone health in American adults.

Targeting bone homeostasis regulation: potential of traditional Chinese medicine flavonoids in the treatment of osteoporosis

Osteoporosis is a systemic metabolic disease characterized by disrupted bone formation/resorption and homeostasis. Flavonoids extracted from traditional Chinese medicinal plants regulate bone homeostasis by intervening in differentiating bone marrow mesenchymal stem cells, balancing the bone immune system, inhibiting oxidative stress response, and reversing iron overload. The target molecules and signaling pathways, such as Wnt/β-catenin and OPG/RANKL/RANK, directly affect osteoblast/osteoclast activity, exhibiting significant potential in the treatment of OP. Therefore, this study presents a systematic review of the recent literature to provide comprehensive information on the traditional Chinese medicine flavonoids involved in the regulation of bone homeostasis. Also, the molecular mechanisms and pharmacological uses of these metabolites are summarized, and their clinical translation and development potential are discussed.

Association of APC Expression with Its Promoter Methylation Status and the Prognosis of Hepatocellular Carcinoma

OBJECTIVE

The present study was aimed to investigate the APC expression, its promoter methylation status, the expression of β-Catenin, c-Myc and Cyclin D1 and further explore their prognostic value in Hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Serum samples from 90 HCC patients and 27 healthy donors were collected in this study. The methylation-specific PCR (MSP) was performed to evaluate promoter methylation status of APC gene. RT-qPCR was used to detect the mRNA expression of APC, β-Catenin, c-Myc and Cyclin D1, meanwhile the protein expression were analyzed by Western blot.

RESULTS

The positive rate of APC gene methylation in HCC patients (46.67%) was higher than healthy donors (11.11%). APC gene exhibited marked hypermethylation in the patients of TNM III-IV stage when compared to the patients of TNM I-II stage , the methylation status of APC gene was correlated with tumor size and lymph node metastasis whereas the APC gene methylation showed no relationship with the patient's sex and age. APC methylation may be associated with APC expression level, APC expression in HCC cells is silenced by aberrant promoter hypermethylation. In HCC patients with methylated APC, the mRNA and protein expression of β-Catenin, c-Myc and Cyclin D1 were higher than the unmethylated patient subgroup and healthy donors.

CONCLUTIONS

The downregulation of APC in HCC samples was associated with promoter hypermethylation. APC methylation could be used as a novel diagnostic biomarker in HCC, which was associated with regulation of Wnt/β-Catenin signal pathway.

The m6A Reader YTHDF1 Accelerates the Osteogenesis of Bone Marrow Mesenchymal Stem Cells Partly via Activation of the Autophagy Signaling Pathway

N6-methyladenosine (m6A) mRNA methylation has emerged as an important player in many biological processes by regulating gene expression. As a crucial reader, YTHDF1 usually improves the translation efficiency of its target mRNAs. However, its roles in bone marrow mesenchymal stem cells (BMSCs) osteogenesis remain largely unknown. Here, we reported that YTHDF1, an m6A reader, is highly expressed during osteogenic differentiation of BMSCs. Upregulation of YTHDF1 increased osteogenic differentiation and proliferation capacity of BMSCs. Accordingly, downregulation of YTHDF1 inhibited osteogenic differentiation and proliferation capacity. Possible underlying mechanisms were explored, and analysis revealed that YTHDF1 could affect autophagy levels, thus regulating osteogenesis of BMSCs. In an in vivo study, we found that upregulation of YTHDF1 accelerates fracture healing with elevated bone volume fraction and trabecular thickness. Taken together, our study revealed that m6A reader YTHDF1 accelerates osteogenic differentiation of BMSCs partly via the autophagy signaling pathway. These findings reveal a previously unrecognized mechanism involved in the regulation of BMSCs osteogenesis, providing new ideas and target sites for the treatment of fracture.

The Development of Naringin for Use against Bone and Cartilage Disorders

Bone and cartilage disorders are the leading causes of musculoskeletal disability. There is no absolute cure for all bone and cartilage disorders. The exploration of natural compounds for the potential therapeutic use against bone and cartilage disorders is proving promising. Among these natural chemicals, naringin, a flavanone glycoside, is a potential candidate due to its multifaceted pharmacological activities in bone and cartilage tissues. Emerging studies indicate that naringin may promote osteogenic differentiation, inhibit osteoclast formation, and exhibit protective effects against osteoporosis in vivo and in vitro. Many signaling pathways, such as BMP-2, Wnt/β-catenin, and VEGF/VEGFR, participate in the biological actions of naringin in mediating the pathological development of osteoporosis. In addition, the anti-inflammatory, anti-oxidative stress, and anti-apoptosis abilities of naringin also demonstrate its beneficial effects against bone and cartilage disorders, including intervertebral disc degeneration, osteoarthritis, rheumatoid arthritis, bone and cartilage tumors, and tibial dyschondroplasia. Naringin exhibits protective effects against bone and cartilage disorders. However, more efforts are still needed due to, at least in part, the uncertainty of drug targets. Further biological and pharmacological evaluations of naringin and its applications in bone tissue engineering, particularly its therapeutic effects against osteoporosis, might result in developing potential drug candidates.