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Frontiers in Cellular and Infection... 2024is a major causative pathogen of osteomyelitis. Intracellular infections of resident bone cells including osteocytes can persist despite gold-standard clinical...
is a major causative pathogen of osteomyelitis. Intracellular infections of resident bone cells including osteocytes can persist despite gold-standard clinical intervention. The mechanisms by which intracellular evades antibiotic therapy are unknown. In this study, we utilised an infection model of human osteocytes to investigate whether antibiotic-mediated dysregulation of autophagy contributes to this phenomenon. Infected or non-infected osteocyte-like cells were exposed to combinations of rifampicin, vancomycin, and modulators of autophagy. Intracellular bacterial growth characteristics were assessed using colonyforming unit (CFU) analysis, viable bacterial DNA abundance, and the rate of escape into antibiotic-free medium, together with measures of autophagic flux. Rifampicin, alone or in combination with vancomycin, caused a rapid decrease in the culturability of intracellular bacteria, concomitant with stable or increased absolute bacterial DNA levels. Both antibiotics significantly inhibited autophagic flux. However, modulation of autophagic flux did not affect viable bacterial DNA levels. In summary, autophagy was shown to be a factor in the host-pathogen relationship in this model, as its modulation affected the growth state of intracellular with respect to both their culturability and propensity to escape the intracellular niche. While rifampicin and vancomycin treatments moderately suppressed autophagic flux acutely, this did not explain the paradoxical response of antibiotic treatment in decreasing culturability whilst failing to clear bacterial DNA and hence intracellular bacterial load. Thus, off-target effects of rifampicin and vancomycin on autophagic flux in osteocyte-like cells could not explain the persistent infection in these cells.
Topics: Autophagy; Staphylococcus aureus; Osteocytes; Anti-Bacterial Agents; Humans; Vancomycin; Rifampin; Staphylococcal Infections; Host-Pathogen Interactions; DNA, Bacterial
PubMed: 38915921
DOI: 10.3389/fcimb.2024.1403289 -
Frontiers in Physiology 2024O-GlcNAcylation, as a post-translational modification, can modulate cellular activities such as kinase activity, transcription-translation, protein degradation, and... (Review)
Review
O-GlcNAcylation, as a post-translational modification, can modulate cellular activities such as kinase activity, transcription-translation, protein degradation, and insulin signaling by affecting the function of the protein substrate, including cellular localization of proteins, protein stability, and protein/protein interactions. Accumulating evidence suggests that dysregulation of O-GlcNAcylation is associated with disease progression such as cancer, neurodegeneration, and diabetes. Recent studies suggest that O-GlcNAcylation is also involved in the regulation of osteoblast, osteoclast and chondrocyte differentiation, which is closely related to the initiation and development of bone metabolic diseases such as osteoporosis, arthritis and osteosarcoma. However, the potential mechanisms by which O-GlcNAcylation regulates bone metabolism are not fully understood. In this paper, the literature related to the regulation of bone metabolism by O-GlcNAcylation was summarized to provide new potential therapeutic strategies for the treatment of orthopedic diseases such as arthritis and osteoporosis.
PubMed: 38915778
DOI: 10.3389/fphys.2024.1416967 -
Journal of Cancer 2024T-box transcription factor 3 (TBX3) has been implicated in various malignant tumors, while its exact involvement in osteosarcoma (OS) remains unknown. Utilizing...
T-box transcription factor 3 (TBX3) has been implicated in various malignant tumors, while its exact involvement in osteosarcoma (OS) remains unknown. Utilizing microarray data and bulk and single-cell RNA-seq data and qRT-PCR, we compared TBX3 mRNA expression levels in different stages of OS. Diagnostic ability testing and prognosis analysis were conducted to better understand the clinical importance of TBX3. Enrichment analysis was performed using gene groups with biological functions similar to TBX3 in different stages of OS to investigate the potential role of TBX3 in OS progression. In addition, we predicted medications targeted at TBX3 and identified downstream target genes to gain a comprehensive understanding of its therapeutic direction and regulatory mechanism. TBX3 expression was highly upregulated in OS and was predominantly expressed in osteoblastic OS cells, with higher expression levels in metastatic tissues. TBX3 expression appeared somewhat suitable for discriminating between OS and normal samples, as well as different stages of OS. We found that TBX3 increased the malignant development of OS by altering cell cycle and cell adhesion molecules; exisulind and tacrolimus, which are targeted small-molecule medicines, were anticipated to counteract this dysregulation. The expression of CCNA2 could potentially be regulated by TBX3, contributing to OS advancement. TBX3 emerges as a potential biomarker for OS. In-depth research into its underlying molecular processes may offer new perspectives on treating OS.
PubMed: 38911382
DOI: 10.7150/jca.96168 -
Synthetic and Systems Biotechnology Dec 2024Collagen XVII (COL17) is a transmembrane protein that mediates skin homeostasis. Due to expression of full length collagen was hard to achieve in microorganisms, arising...
Collagen XVII (COL17) is a transmembrane protein that mediates skin homeostasis. Due to expression of full length collagen was hard to achieve in microorganisms, arising the needs for selection of collagen fragments with desired functions for microbial biosynthesis. Here, COL17 fragments (27-33 amino acids) were extracted and replicated 16 times for recombinant expression in . Five variants were soluble expressed, with the highest yield of 223 mg/L. The fusion tag was removed for biochemical and biophysical characterization. Circular dichroism results suggested one variant (sample-1707) with a triple-helix structure at >37 °C. Sample-1707 can assemble into nanofiber (width, 5.6 nm) and form hydrogel at 3 mg/mL. Sample-1707 was shown to induce blood clotting and promote osteoblast differentiation. Furthermore, sample-1707 exhibited high capacity to induce mouse hair follicle stem cells differentiation and osteoblast migration, demonstrating a high capacity to induce skin cell regeneration and promote wound healing. A strong hydrogel was prepared from a chitosan and sample-1707 complex with a swelling rate of >30 % higher than simply using chitosan. Fed-batch fermentation of sample-1707 with a 5-L bioreactor obtained a yield of 600 mg/L. These results support the large-scale production of sample-1707 as a biomaterial for use in the skin care industry.
PubMed: 38911060
DOI: 10.1016/j.synbio.2024.06.001 -
Retraction Note: Tridax procumbens flavonoids promote osteoblast differentiation and bone formation.Biological Research Jun 2024
PubMed: 38910257
DOI: 10.1186/s40659-024-00525-x -
Bone Research Jun 2024Stem/progenitor cells differentiate into different cell lineages during organ development and morphogenesis. Signaling pathway networks and mechanotransduction are...
Stem/progenitor cells differentiate into different cell lineages during organ development and morphogenesis. Signaling pathway networks and mechanotransduction are important factors to guide the lineage commitment of stem/progenitor cells during craniofacial tissue morphogenesis. Here, we used tooth root development as a model to explore the roles of FGF signaling and mechanotransduction as well as their interaction in regulating the progenitor cell fate decision. We show that Fgfr1 is expressed in the mesenchymal progenitor cells and their progeny during tooth root development. Loss of Fgfr1 in Gli1 progenitors leads to hyperproliferation and differentiation, which causes narrowed periodontal ligament (PDL) space with abnormal cementum/bone formation leading to ankylosis. We further show that aberrant activation of WNT signaling and mechanosensitive channel Piezo2 occurs after loss of FGF signaling in Gli1-Cre;Fgfr1 mice. Overexpression of Piezo2 leads to increased osteoblastic differentiation and decreased Piezo2 leads to downregulation of WNT signaling. Mechanistically, an FGF/PIEZO2/WNT signaling cascade plays a crucial role in modulating the fate of progenitors during root morphogenesis. Downregulation of WNT signaling rescues tooth ankylosis in Fgfr1 mutant mice. Collectively, our findings uncover the mechanism by which FGF signaling regulates the fate decisions of stem/progenitor cells, and the interactions among signaling pathways and mechanotransduction during tooth root development, providing insights for future tooth root regeneration.
Topics: Animals; Wnt Signaling Pathway; Tooth Root; Mechanotransduction, Cellular; Fibroblast Growth Factors; Mice; Cell Differentiation; Stem Cells; Receptor, Fibroblast Growth Factor, Type 1; Ion Channels
PubMed: 38910207
DOI: 10.1038/s41413-024-00345-5 -
Biomedicine & Pharmacotherapy =... Jun 2024Insulin stimulates osteoblast proliferation and differentiation as an anabolic agent in bone. Insulin Receptor Tyrosine Kinase Substrate (IRTKS) is involved in insulin...
Insulin stimulates osteoblast proliferation and differentiation as an anabolic agent in bone. Insulin Receptor Tyrosine Kinase Substrate (IRTKS) is involved in insulin signaling as an adapter for insulin receptors (IR). Here, we showed that IRTKS levels were significantly decreased in bone marrow mesenchymal stem cells (BMSCs) derived from the bone marrow of patients with osteoporosis. Based on relevant experiments, we observed that IRTKS promoted the proliferation, migration, and osteoblast differentiation of BMSCs and MC3T3-E1 cells. In addition, we identified a Phosphatase and Tensin homolog deleted on chromosome 10 (PTEN) as a potential active substrate of IRTKS. We demonstrated a direct interaction between IRTKS and PTEN using co-immunoprecipitation. Subsequently, we confirmed that the SH3 domain of IRTKS directly binds to the C-terminal tail of PTEN. Further experimental results demonstrated that PTEN attenuated the promoting effects of IRTKS on the proliferation, migration, and osteoblast differentiation of BMSCs and MC3T3-E1 cells. In conclusion, this study suggests that IRTKS contributes to osteogenic differentiation by inhibiting PTEN phosphorylation and provides a potential therapeutic target for osteoporosis patients.
PubMed: 38908202
DOI: 10.1016/j.biopha.2024.116872 -
Journal of Orthopaedic Surgery and... Jun 2024Long non-coding RNAs (LncRNAs) are recognized as a pivotal element in the processes of fracture healing and the osteogenic differentiation of stem cells. This study...
BACKGROUND
Long non-coding RNAs (LncRNAs) are recognized as a pivotal element in the processes of fracture healing and the osteogenic differentiation of stem cells. This study investigated the molecular mechanism and regulatory significance of lncRNA MAGI2-AS3 (MAGI2-AS3) in fracture healing.
METHODS
Serum levels of MAGI2-AS3 in patients with normal and delayed fracture healing were verified by RT-qPCR assays. The predictive efficacy of MAGI2-AS3 for delayed fracture healing was analyzed by ROC curve. Osteogenic markers were quantified by RT-qPCR assays. MC3T3-E1 cell viability was detected using CCK-8 assay, and flow cytometry was utilized to measure cell apoptosis. The dual-luciferase reporter gene assay was used to determine the targeted binding between MAGI2-AS3 and miR-223-3p.
RESULTS
Serum MAGI2-AS3 expression was decreased in patients with delayed fracture healing compared with patients with normal healing. Elevated MAGI2-AS3 resulted in an upregulation of the proliferative capacity of MC3T3-E1 cells and a decrease in mortality, along with increased levels of both osteogenic markers. However, after transfection silencing MAGI2-AS3, the trend was reversed. Additionally, miR-223-3p was the downstream target of MAGI2-AS3 and was controlled by MAGI2-AS3. miR-223-3p mimic reversed the promoting effects of MAGI2-AS3 overexpression on osteogenic marker levels and cell growth, and induced cell apoptosis.
CONCLUSION
The upregulation of MAGI2-AS3 may expedite the healing of fracture patients by targeting miR-223-3p, offering a novel biomarker for diagnosing patients with delayed healing.
Topics: MicroRNAs; RNA, Long Noncoding; Fracture Healing; Humans; Down-Regulation; Mice; Animals; Osteogenesis; Male; Female; Apoptosis; Adaptor Proteins, Signal Transducing; Adult; Cell Proliferation; Cell Differentiation
PubMed: 38907263
DOI: 10.1186/s13018-024-04850-5 -
Biomedicine & Pharmacotherapy =... Jun 2024Osteoporosis, characterized by compromised bone density and microarchitecture, represents a significant global health challenge, particularly in aging populations. This... (Review)
Review
Osteoporosis, characterized by compromised bone density and microarchitecture, represents a significant global health challenge, particularly in aging populations. This comprehensive review delves into the intricate signaling pathways implicated in the pathogenesis of osteoporosis, providing valuable insights into the pivotal role of signal transduction in maintaining bone homeostasis. The exploration encompasses cellular signaling pathways such as Wnt, Notch, JAK/STAT, NF-κB, and TGF-β, all of which play crucial roles in bone remodeling. The dysregulation of these pathways is a contributing factor to osteoporosis, necessitating a profound understanding of their complexities to unveil the molecular mechanisms underlying bone loss. The review highlights the pathological significance of disrupted signaling in osteoporosis, emphasizing how these deviations impact the functionality of osteoblasts and osteoclasts, ultimately resulting in heightened bone resorption and compromised bone formation. A nuanced analysis of the intricate crosstalk between these pathways is provided to underscore their relevance in the pathophysiology of osteoporosis. Furthermore, the study addresses some of the most crucial long non-coding RNAs (lncRNAs) associated with osteoporosis, adding an additional layer of academic depth to the exploration of immune system involvement in various types of osteoporosis. Finally, we propose that SKP1 can serve as a potential biomarker in osteoporosis.
PubMed: 38906027
DOI: 10.1016/j.biopha.2024.116954 -
Frontiers in Endocrinology 2024Magnesium (Mg), a nutritional element which is essential for bone development and mineralization, has a role in the progression of osteoporosis. Osteoporosis is a... (Review)
Review
Magnesium (Mg), a nutritional element which is essential for bone development and mineralization, has a role in the progression of osteoporosis. Osteoporosis is a multifactorial disease characterized by significant deterioration of bone microstructure and bone loss. Mg deficiency can affect bone structure in an indirect way through the two main regulators of calcium homeostasis (parathyroid hormone and vitamin D). In human osteoblasts (OBs), parathyroid hormone regulates the expression of receptor activator of nuclear factor-κ B ligand (RANKL) and osteoprotegerin (OPG) to affect osteoclast (OC) formation. In addition, Mg may also affect the vitamin D3 -mediated bone remodeling activity. vitamin D3 usually coordinates the activation of the OB and OC. The unbalanced activation OC leads to bone resorption. The RANK/RANKL/OPG axis is considered to be a key factor in the molecular mechanism of osteoporosis. Mg participates in the pathogenesis of osteoporosis by affecting the regulation of parathyroid hormone and vitamin D levels to affect the RANK/RANKL/OPG axis. Different factors affecting the axis and enhancing OC function led to bone loss and bone tissue microstructure damage, which leads to the occurrence of osteoporosis. Clinical research has shown that Mg supplementation can alleviate the symptoms of osteoporosis to some extent.
Topics: Humans; Osteoporosis; Magnesium; Animals; Parathyroid Hormone; RANK Ligand; Osteoblasts; Bone Remodeling; Vitamin D; Magnesium Deficiency; Osteoclasts; Osteoprotegerin
PubMed: 38904051
DOI: 10.3389/fendo.2024.1406248