Periostin/Bone Morphogenetic Protein 1 axis axis regulates proliferation and osteogenic differentiation of sutured mesenchymal stem cells and affects coronal suture closure in the TWIST1+/- mouse model of craniosynostosis.

BACKGROUND AND OBJECTIVE: The pathogenesis of coronal suture craniosynostosis is often attributed to the dysregulated cellular dynamics, particularly the excessive proliferation and abnormal osteogenic differentiation of suture cells. Despite its clinical significance, the molecular mechanims of this condition remain inadequately understood. This study is dedicated to exploring the influence of the Periostin/Bone Morphogenetic Protein 1 (BMP1) axis on the growth and osteogenic maturation of Suture Mesenchymal Stem Cells (SMSCs), which are pivotal in suture homeostasis. METHODS: Neonatal TWIST Basic Helix-Loop-Helix Transcription Factor 1 heterozygous (TWIST1+/-) mice, aged one day, were subjected to adenoviral vector-mediated Periostin upregulation. To modulate Periostin/BMP1 levels in SMSCs, we employed siRNA and pcDNA 3.1 vectors. Histological and molecular characterizations, including hematoxylin and eosin staining, Western blot, and immunohistochemistry were employed to study suture closure phenotypes and protein expression patterns. Cellular assays, encompassing colony formation, 5-ethynyl-2'deoxyuridine, and wound healing tests were conducted to analyze SMSC proliferation and migration. Osteogenic differentiation was quantified using Alkaline Phosphatase (ALP) and Alizarin Red S (ARS) staining, while protein markers of proliferation and differentiation were evaluated by Western blotting. The direct interaction between Periostin and BMP1 was validated through co-immunoprecipitation assays. RESULTS: In the TWIST1+/- model, an upregulation of Periostin coupled with a downregulation of BMP1 was observed. Augmenting Periostin expression mitigated craniosynostosis. In vitro, overexpression of Periostin or BMP1 knockdown suppressed SMSC proliferation, migration, and osteogenic differentiation. Periostin knockdown manifested an inverse biological impact. Notably, the suppressive influence of Periostin overexpression on SMSCs was effectively counteracted by upregulating BMP1. There was a direct interaction between Periostin and BMP1. CONCLUSION: These findings underscore the significance of the Periostin/BMP1 axis in regulating craniosynostosis and SMSC functions, providing new insights into the molecular mechanisms of craniosynostosis and potential targets for therapeutic intervention.

An efficient and universal In silico screening strategy for acquisition of high-affinity Aptamer and its application in analytical utility.

Numerous aptamers against various targets have been identified through the technology of systematic evolution of ligands by exponential enrichment (SELEX), but the affinity of these aptamers are often insufficient due to the limitations of SELEX. Therefore, a more rational in silico screening strategy (ISS) was developed for efficient screening of high affinity aptamers, which took shape complementarity and thermodynamic stability into consideration. Neuron specific enolase (NSE), a tumor marker, was selected as the target molecule. In the screening process, three aptamer candidates with good shape complementarity, lower ΔG values, and higher ZDOCK scores were produced. The dissociation constant (Kd) of these candidates to NSE was determined to be 10.13 nM, 14.82 nM, and 2.76 nM, respectively. Each of them exhibited higher affinity to NSE than the parent aptamer (Kd = 23.83 nM). Finally, an antibody-free fluorescence aptasensor assay, based on the aptamer with the highest affinity, P-5C8G, was conducted, resulting in a limit of detection (LOD) value of 1.8 nM, which was much lower than the parental aptamer (P, LOD = 12.6 nM). The proposed ISS approach provided an efficient and universal strategy to improve the aptamer to have a high affinity and good analytical utility.