A study of hydrophobins-modified menaquinone-7 on osteoblastic cells differentiation

Mongolian medicine Sugemule-7 decoction prevents osteoporosis via Erk1/2 and p38 MAPK signaling pathways according to network pharmacology analysis

Osteoporosis (OP) is a significant global public health concern that requires the development of safe and effective drugs for prevention and treatment. Sugemule-7 (SGML-7) decoction, a traditional Mongolian herbal prescription, has long been used for treating OP, but its components and mechanisms of action remain unclear. The study identified the main compounds of SGML-7 using UHPLC-Q Exactive MS and explored the multi-target mechanisms of SGML-7 in OP through network pharmacology and molecular docking. A retinoic acid (RA)-induced mouse OP model was utilized to confirm the therapeutic effects and potential mechanism of SGML-7. Additionally, mouse pre-osteoblastic (MC3T3-E1) cells treated with SGML-7 medicated serum were employed to delve deeper into the molecular mechanisms. The UHPLC-Q Exactive MS analysis, network pharmacology, and molecular docking suggested that the synergistic effect of multiple active compounds could be the main contributor to SGML-7 for its anti-OP activities. Moreover, MAPK1, JUN, ESR1, TP53, AKT1, NCOA1, FOS, and NR3C1 were identified as potential key targets, and the MAPK signaling pathway was among the signaling pathways possibly involved in the anti-OP activities of SGML-7. Consistent with these findings, experimental studies confirmed that SGML-7 prevented bone loss, enhanced bone quality in OP mice, and promoted osteoblastic activity and bone formation in MC3T3-E1 cells by modulating MAPK-associated targets. Taken together, SGML-7 shows promise as an effective and appealing anti-OP drug candidate.

Bacillus subtilis Modulated the Expression of Osteogenic Markers in a Human Osteoblast Cell Line

Several in vivo trials have previously demonstrated the beneficial effects of the administration of various probiotic forms on bone health. In this study, we explored the potency of two probiotics, Bacillus subtilis and Lactococcus lactis, alone or in combination with vitamin D (VD), to modulate the transcription of genes involved in the ossification process in a human osteoblast cell line. Genes that mark the "osteoblast proliferation phase", such as RUNX2, TGFB1, and ALPL, "extracellular matrix (ECM) maturation", such as SPP1 and SPARC, as well as "ECM mineralization", such as BGN, BGLAP, and DCN, were all highly expressed in osteoblasts treated with B. subtilis extract. The observed increase in the transcription of the ALPL mRNA was further in agreement with its protein levels as observed by Western blot and immunofluorescence. Therefore, this higher transcription and translation of alkaline phosphatase in osteoblasts treated with the B. subtilis extract, indicated its substantial osteogenic impact on human osteoblasts. Although both the probiotic extracts showed no osteogenic synergy with VD, treatment with B. subtilis alone could increase the ECM mineralization, outperforming the effects of L. lactis and even VD. Furthermore, these results supported the validity of employing probiotic extracts rather than live cells to investigate the effects of probiotics in the in vitro systems.

Enhancement of Vitamin K2 Efflux in Bacillus subtilis Natto via a Potential Protein Receptor for Increased Yield

Bacillus subtilis is one of the few strains that can secrete synthetic menaquinone-7 (MK-7) to the outside of the cell, and its purpose and mechanism have not been clearly studied. As an amphiphilic protein naturally synthesized by Bacillus subtilis, the BslA protein may be involved in the inversion of extracellular vitamin K2 solubility. The protein structure in UniProt was used to search for the possible binding sites of MK-7, and the analysis of the higher ranking results of the genetic algorithm showed that the ASP166 residue was likely to be the binding site. They could form a stable hydrogen bond connection through ASP166, and approximately 7 proteins formed the conformation of a fixed naphthoquinone ring. We isolated and obtained the BslA protein by Ni-NTA affinity chromatography. Then, MK-7 was modified by BslA in vitro. A series of experiments, such as SEM, XPS, and WCA, showed that MK-7 and BslA proteins can realize self-assembly and transform from fat-soluble to water-soluble complexes. When the bslA protein in Bacillus subtilis natto was overexpressed, its MK-7 synthesis ability was further improved, especially the extracellular MK-7 content, which increased by 16%. This finding suggests that the BslA protein in Bacillus subtilis is likely to be involved in the extracellular secretion of MK-7 as a receptor.