Osteoblastic microRNAs in skeletal diseases: Biological functions and therapeutic implications

Gene expression and hormonal signaling in osteoporosis: from molecular mechanisms to clinical breakthroughs

Osteoporosis is well noted to be a universal ailment that realization impaired bone mass and micro architectural deterioration thus enhancing the probability of fracture. Despite its high incidence, its management remains highly demanding because of the multifactorial pathophysiology of the disease. This review highlights recent findings in the management of osteoporosis particularly, gene expression and hormonal control. Some of the newest approaches regarding the subject are described, including single-cell RNA sequencing and long non-coding RNAs. Also, the review reflects new findings on hormonal signaling and estrogen and parathyroid hormone; patient-specific approaches due to genetic and hormonal variation. Potential new biomarkers and AI comprised as factors for improving the ability to anticipate and manage fractures. These hold great potential of new drugs, combination therapies and gene based therapies for osteoporosis in the future. Further studies and cooperation of scientists and clinicians will help to apply such novelties into practical uses in the sphere of medicine in order to enhance the treatment of patients with osteoporosis.

Comprehensive Overview of Interface Strategies in Implant Osseointegration

With the improvement of implant design and the expansion of application scenarios, orthopedic implants have become a common surgical option for treating fractures and end‐stage osteoarthritis. Their common goal is rapidly forming and long‐term stable osseointegration. However, this fixation effect is limited by implant surface characteristics and peri‐implant bone tissue activity. Therefore, this review summarizes the strategies of interface engineering (osteogenic peptides, growth factors, and metal ions) and treatment methods (porous nanotubes, hydrogel embedding, and other load‐release systems) through research on its biological mechanism, paving the way to achieve the adaptation of both and coordination between different strategies. With the transition of the osseointegration stage, interface engineering strategies have demonstrated varying therapeutic effects. Especially, the activity of osteoblasts runs almost through the entire process of osseointegration, and their physiological activities play a dominant role in bone formation. Furthermore, diseases impacting bone metabolism exacerbate the difficulty of achieving osseointegration. This review aims to assist future research on osseointegration engineering strategies to improve implant‐bone fixation, promote fracture healing, and enhance post‐implantation recovery.

MicroRNA-138: an emerging regulator of skeletal development, homeostasis, and disease

Noncoding microRNAs are powerful epigenetic regulators of cellular processes by their ability to target and suppress expression of numerous protein-coding mRNAs. This multitargeting function is a unique and complex feature of microRNAs. It is now well-described that microRNAs play important roles in regulating the development and homeostasis of many cell/tissue types, including those that make up the skeletal system. In this review, we focus on microRNA-138 (miR-138) and its effects on regulating bone and cartilage cell differentiation and function. In addition to its reported role as a tumor suppressor, miR-138 appears to function as an inhibitor of osteoblast differentiation. This review provides additional information on studies that have attempted to alter miR-138 expression in vivo as a means to dampen ectopic calcification or alter bone mass. However, a review of the published literature on miR-138 in cartilage reveals a number of contradictory and inconclusive findings with respect to regulating chondrogenesis and chondrocyte catabolism. This highlights the need for more research in understanding the role of miR-138 in cartilage biology and disease. Interestingly, a number of studies in other systems have reported miR-138-mediated effects in dampening inflammation and pain responses. Future studies will reveal if a multifunctional role of miR-138 involving suppression of ectopic bone, inflammation, and pain will be beneficial in skeletal conditions such as osteoarthritis and heterotopic ossification.

microRNA hsa-miR-425-5p and hsa-miR-4523 expressions as biomarkers of active pulmonary tuberculosis, latent tuberculosis infection, and lymph node tuberculosis

BACKGROUND

Studies on miRNA highlight its significance as an immunomarker for several diseases, including tuberculosis. This study aimed to determine the difference between miR-425-5p and miR-4523 expressions in patients with active pulmonary TB (PTB), latent TB infection (LTBI), and lymph node TB (LNTB), whose diagnosis remains challenging.

METHODS

This case-control study was performed on blood samples obtained from 23 patients with PTB, 21 with LTBI, 21 with LNTB, and 25 healthy controls (HC). miRNA hsa-miR-425-5p and hsa-miR-4523 expression levels were measured by RT-qPCR. Statistical analyses were performed using SPSS version 25.0.

RESULTS

RT-qPCR showed that hsa-mir-425-5p and hsa-mir-4523 expression levels were significantly different among the four groups (PTB, LTBI, LNTB, and HCs). The hsa-mir-425-5p miRNA expression level in LNTB was higher than that in LTBI (p = 0.003). Meanwhile, the hsa-mir-4523 miRNA expression was downregulated in PTB and LNTB than in LTBI (p < 0.0001 and p = 0.015, respectively). The ROC analysis of a single sample showed that only mir-4523 could discriminate LTBI and HCs, with an AUC of 0.829 (p < 0.001). The ROC curve of each miRNA was further analyzed after logistic regression by adjusting for sex and age. The combination of both miRNAs was also analyzed. The model that analyzed the combination of both miRNAs after adjusting for age had the best performance in differentiating LNTB from LTBI, with an AUC of 0.97 (p < 0.001).

CONCLUSION

miRNA hsa-mir-425-5p was upregulated and miRNA hsa-mir-4523 was downregulated in PTB and LNTB than in LTBI.

Engineering Stem Cell Recruitment and Osteoinduction via Bioadhesive Molecular Mimics to Improve Osteoporotic Bone-Implant Integration

For patients with osteoporosis, the therapeutic outcomes of osteoimplants are substantially affected by the impaired proliferation, migration, and osteogenic differentiation abilities of bone marrow mesenchymal stem cells (BMSCs). To improve bone-implant integration in osteoporotic condition, here we reported a one-step biomimetic surface strategy to introduce BMSC recruiting and osteoinductive abilities onto metallic osteoimplants. In our design, the bioadhesive molecular peptide mimic inspired by mussel foot proteins (Mfps) was used as molecular bridging for surface functionalization. Specifically, a BMSC-targeting peptide sequence (E7) and an osteogenic growth peptide (Y5) were grafted onto the titanium implant surfaces through a mussel adhesion mechanism. We found that a rational E7/Y5 feeding ratio could lead to an optimal dual functionalization capable of not only significantly improving the biocompatibility of the implant but also enabling it to recruit endogenous BMSCs for colonization, proliferation, and osteogenic differentiation. Mechanistically, the E7-assisted in situ recruitment of endogenous BMSCs as well as the enhanced interfacial osteogenesis and osteointegration was associated with activation of the C-X-C chemokine receptor type 4 (CXCR4) receptor on the cell surface and promotion of stromal cell-derived factor (SDF-1α) autocrine secretion. We anticipated that rational dual-functional surfaces through bioadhesive molecular mimics will provide a simple, effective, nonimmunogenic, and safe means to improve the clinical outcomes of intraosseous implants, especially under osteoporotic conditions.