Lipoic acid (LA) dose-dependently protects bone losses in the mandible of rats during the development of osteopenia by inhibiting oxidative stress and promoting bone formation

The mechanism of Se(IV) multisystem resistance in Stenotrophomonas sp. EGS12 and its prospect in selenium-contaminated environment remediation

Human activities have led to elevated levels of selenium (Se) in the environment, which poses a threat to ecosystems and human health. Stenotrophomonas sp. EGS12 (EGS12) has been identified as a potential candidate for the bioremediation of repair selenium-contaminated environment because of its ability to efficiently reduce Se(IV) to form selenium nanospheres (SeNPs). To better understand the molecular mechanism of EGS12 in response to Se(IV) stress, a combination of transmission electron microscopy (TEM), genome sequencing techniques, metabolomics and transcriptomics were employed. The results indicated that under 2 mM Se(IV) stress, 132 differential metabolites (DEMs) were identified, and they were significantly enriched in metabolic pathways such as glutathione metabolism and amino acid metabolism. Under the Se(IV) stress of 2 mM, 662 differential genes (DEGs) involved in heavy metal transport, stress response, and toxin synthesis were identified in EGS12. These findings suggest that EGS12 may respond to Se(IV) stress by engaging various mechanisms such as forming biofilms, repairing damaged cell walls/cell membranes, reducing Se(IV) translocation into cells, increasing Se(IV) efflux, multiplying Se(IV) reduction pathways and expelling SeNPs through cell lysis and vesicular transport. The study also discusses the potential of EGS12 to repair Se contamination alone and co-repair with Se-tolerant plants (e.g. Cardamine enshiensis). Our work provides new insights into microbial tolerance to heavy metals and offers valuable information for bio-remediation techniques on Se(IV) contamination.

Association between mixed aldehydes and bone mineral density based on four statistical models

Aldehydes as an environmental pollutant may lead to oxidative stress, which is an important mechanism in the development of osteoporosis. This suggests a possible link between aldehyde exposure and osteoporosis. Considering the mixed nature of aldehyde exposure and the interactions between different aldehydes, we explored for the first time the associations between mixed six aldehydes (benzaldehyde, butyraldehyde, heptanal, hexanal, isovaleraldehyde, and propionaldehyde) and BMD in three populations (men, premenopausal women, and postmenopausal women) by applying four statistical models: quantile g-computation (qgcomp) model, Bayesian kernel machine regression (BKMR) model, generalized linear regression model (GLM), and generalized additive model (GAM), based on the National Health and Nutrition Examination Survey (NHANES) 2013-2014. We found that mixed aldehydes could significantly reduce BMD in men, with hexanaldehyde and propanaldehyde having the greatest negative qgcomp model and BKMR model weights, also confirmed by GLM. The associations between isopentanaldehyde and propanaldehyde and femoral BMD in men were non-linear and had threshold effects as derived from the BKMR model and GAM. The associations turned positive when the concentrations of isopentanaldehyde and propanaldehyde exceeded their respective inflection points. To conclude, our study might provide new ideas for the prevention and treatment of osteoporosis, and hexanaldehyde and propanaldehyde should be more regulated to prevent osteoporosis.

Therapeutic Potential of Berberine for Osteoporosis and its Underlying Mechanisms: A Bioinformatics, Network Pharmacology, Molecular Dynamics Simulation Study

Osteoporosis is a systemic skeletal disease that can easily lead to bone fractures. Berberine has been shown to be effective in treating osteoporosis. This study was conducted to identify the potential mechanism of berberine in treating this complaint. We screened potential targets of berberine and identified the osteoporosis-related differentially expressed genes (DEGs) in the microarray dataset GSE56815. Protein–protein interaction (PPI) network construction, hub targets identification, and pathway enrichment were carried out to find the potential targets. Molecular docking and molecular dynamics studies were performed to verify the combination of berberine with its treatment-related central targets. In addition, SwissADME preliminarily evaluated the physicochemical properties of berberine. Through data mining, 23 osteoporosis-related targets of berberine were selected. PPI and module analyses suggested that AKT1, MAPK1, ESR1, AR, TP53, and PTGS2 are the core targets of berberine. Docking and molecular dynamics studies showed that berberine could stably bind to core proteins to form a protein–ligand complex. The enrichment analysis showed that the estrogen signaling pathway and thyroid hormone signaling pathway play important roles in curing osteoporosis. To sum up, berberine primarily acts on AKT1, MAPK1, ESR1, AR, TP53, and PTGS2, mainly regulating the estrogen and thyroid hormone signaling pathways to treat osteoporosis in a multi-target, multi-pathway, and multi-system manner.

Targeting Sirt1, AMPK, Nrf2, CK2, and Soluble Guanylate Cyclase with Nutraceuticals: A Practical Strategy for Preserving Bone Mass

There is a vast pre-clinical literature suggesting that certain nutraceuticals have the potential to aid the preservation of bone mass in the context of estrogen withdrawal, glucocorticoid treatment, chronic inflammation, or aging. In an effort to bring some logical clarity to these findings, the signaling pathways regulating osteoblast, osteocyte, and osteoclast induction, activity, and survival are briefly reviewed in the present study. The focus is placed on the following factors: the mechanisms that induce and activate the RUNX2 transcription factor, a key driver of osteoblast differentiation and function; the promotion of autophagy and prevention of apoptosis in osteoblasts/osteoclasts; and the induction and activation of NFATc1, which promotes the expression of many proteins required for osteoclast-mediated osteolysis. This analysis suggests that the activation of sirtuin 1 (Sirt1), AMP-activated protein kinase (AMPK), the Nrf2 transcription factor, and soluble guanylate cyclase (sGC) can be expected to aid the maintenance of bone mass, whereas the inhibition of the serine kinase CK2 should also be protective in this regard. Fortuitously, nutraceuticals are available to address each of these targets. Sirt1 activation can be promoted with ferulic acid, N1-methylnicotinamide, melatonin, nicotinamide riboside, glucosamine, and thymoquinone. Berberine, such as the drug metformin, is a clinically useful activator of AMPK. Many agents, including lipoic acid, melatonin, thymoquinone, astaxanthin, and crucifera-derived sulforaphane, can promote Nrf2 activity. Pharmacological doses of biotin can directly stimulate sGC. Additionally, certain flavonols, notably quercetin, can inhibit CK2 in high nanomolar concentrations that may be clinically relevant. Many, though not all, of these agents have shown favorable effects on bone density and structure in rodent models of bone loss. Complex nutraceutical regimens providing a selection of these nutraceuticals in clinically meaningful doses may have an important potential for preserving bone health. Concurrent supplementation with taurine, N-acetylcysteine, vitamins D and K2, and minerals, including magnesium, zinc, and manganese, plus a diet naturally high in potassium, may also be helpful in this regard.