MicroRNA-425-5p modulates osteoporosis by targeting annexin A2.

BACKGROUND: Studies have shown that the decrease of osteogenic differentiation of bone marrow mesenchymal stem cells (MSC) is an important mechanism of osteoporosis. The object of this study was to explore the role and mechanism of microRNA miR-425-5p in the differentiation of MSC. METHODS: The expression of miR-425-5p in MSC was detected by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Cell proliferation, cell cycle and apoptosis were detected by CCK-8 colorimetry and flow cytometry. The expression of TNF were detected by ELISA. RESULTS: Our data show that MiR-425-5p could modulate TNF-induced cell apoptosis, proliferation, and differentiation. ANXA2 is also the target of miR-425-5p and ANXA2 was involved in TNF-induced MSC cell apoptosis, proliferation, and differentiation. In addition, MiR-425-5p enhanced osteoporosis in mice. CONCLUSION: MiR-425-5p might serve as a potential therapeutic target for the treatment of osteoporosis.

Asiatic Acid Attenuates Bone Loss by Regulating Osteoclastic Differentiation.

Anti-resorptive agents like bisphosphonates have been widely used for the treatment of postmenopausal osteoporosis. However, their long-term safety and efficacy are still controversial. This study is to examine the effect of Asiatic acid (AA) in osteoclastic differentiation, and further to investigate its effect on bone quality in animals. Effect of AA on osteoclastic differentiation was measured by Tartrate-resistant acid phosphatase stain, bone resorption pit assays, and quantitative real-time polymerase chain reaction. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and transforming growth factor-ß (TGF-ß) signaling were measured by western blot before and after AA treatment. Ovariectomized (OVX) wild-type or Smad7 partially knock out mice were used to evaluate the effects of AA on bone quality by micro-computed tomography, mechanical test, and histomorphometry. Results revealed a dose-dependent inhibitory effect of AA on osteoclastic differentiation. After AA treatment, Smad7 was upregulated, while NF-κB and TGF-ß signaling were inhibited during osteoclastic differentiation. Results from animal study revealed that AA prevented bone from further loss caused by OVX and increased the mechanical properties of femur in wild-type animals. AA also prevented bone loss in the Smad7-deficient animals. When combining with OVX in the Smad7-deficient mice, AA could only partially preserve their bone mass. Taken together, we found that AA effectively inhibited osteoclastic differentiation and attenuated osteoporosis, which effects may be through TGF-ß and NF-κB pathways. This study reveals that AA may be a potential anti-resorptive agent for postmenopausal osteoporosis.

Rapidly reducing cadmium from contaminated farmland soil by novel magnetic recyclable Fe3O4/mercapto-functionalized attapulgite beads.

Reducing cadmium (Cd) content from contaminated farmland soils remains a major challenge due to the difficulty in separating commonly used adsorbents from soils. This study synthesized novel millimeter-sized magnetic Fe3O4/mercapto-functionalized attapulgite beads (MFBs) through a facile one-step gelation process incorporating alginate. The MFBs inherit the environmental stability of alginate and enhance its mechanical strength by hybridizing Fe3O4 and clay mineral components. MFBs can be easily separated from flooded soils by magnets. When applied to 12 Cd-polluted paddy soils and 14 Cd-polluted upland soils, MFBs achieved Cd(II) removal rates ranging from 16.9% to 62.2% and 9.8%-54.6%, respectively, within a 12-h period. The MFBs predominantly targeted the exchangeable and acid soluble, and reducible fractions of Cd, with significantly enhanced removal efficiencies in paddy soils compared to upland soils. Notably, MFBs exhibited superior adsorption performance in soils with lower pH and organic matter (OM) content, where the bioavailability and mobility of Cd are heightened. The reduction of Cd content by MFBs is a sustainable and safe method, as it permanently removes the bioavailable Cd from soil, rather than temporarily reducing its bioavailability. The functional groups such as -SH, -OH, present in attapulgite and alginate of MFBs, played a crucial role in Cd(II) adsorption. Additionally, attapulgite and zeolite provided a porous matrix structure that further enhanced Cd(II) adsorption. The results of X-ray photoelectron spectroscopy suggested that both chemical precipitation and surface complexation contributed to Cd(II) removal. The MFBs maintained 87.6% Cd removal efficiency after 5 regeneration cycles. The surface of the MFBs exposed new adsorption sites and increased the specific surface area during multiple cycles with Cd-contaminated soil. This suggests that MFBs treatment with magnetic retrieval is a potentially effective pathway for the rapid removal of Cd from contaminated farmland soils.

Micron-confined microcapturer-triggered Fenton as efficient and environmentally-friendly method for simultaneously capturing bloom-forming cyanobacteria, inhibiting cell-regrowth and degrading microcystins.

The frequent outbreak and continuous expansion of harmful cyanobacteria blooms (HCBs) have become important environmental concerns and public health issues globally. In this study, the "micron-confined Fe(II)-modified-microcapturer (FMC)-triggered Fenton" technology was established as advanced process adaptable to the HCB treatment. Results show that 95.7-99.4% of cyanobacteria cells were captured and separated from the HCB water at the optimum doses of Fe(II) and H2O2 within only 30 s. The chain-like cyanobacteria of A. flos-aquae were easier to be collected by FMCs compared with the unicellular M. aeruginosa. It was confirmed by scanning electron microscopic observation and fluorescence staining flow cytometry measurement that the FMC-carrying Fe(II) played the roles of both cell-gripper and Fenton catalyst. During the one-step process, the FMC-triggered Fenton effectively inhibited the cyanobacteria regrowth via inactivating the cells, and meanwhile, the microcystins of LR and RR were removed. The analyses by continuous flow chemiluminescence and X-ray photoelectron spectroscopy denote that FMCs performed efficiently in capture and Fe(II)-catalytic oxidation through increasing mass transfer, exposing sufficient active reactive oxygen species active-sites on the FMC surface and accelerating electron transfer. The micron-field-confined cascade processes retained the robust performance of Fenton against the high pH of bulk HCB water. This novel interface-dependent Fenton method is a promising tool for HCB treatment owing to its great efficiency, versatility, rapidness and eco-environmental friendliness.

Morphologically-different cells and colonies cause distinctive performance of coagulative colloidal ozone microbubbles in simultaneously removing bloom-forming cyanobacteria and microcystin-LR.

Morphology, the important feature of bloom-forming cyanobacteria, was studied for its impacts on the harmful cyanobacterial bloom (HCB) treatment by coagulative colloidal ozone microbubbles (CCOMBs). The globally-appeared HCB species - Microcystis aeruginosa (spherical cells, block mass colonies), Microcystis panniformis (spherical cells, flat penniform-like colonies) and Anabaena flos-aquae (filamentous morphology) were chosen as representative species. CCOMBs were generated by modifying the bubble surface and the gas core with coagulant and ozone, respectively. The removal of spherical cells and filaments was > 99.5% and ≤ 34.6%, individually, and the latter was ascribed to chain breakage. CCOMBs collected Microcystis panniformis via complexing with the fluorescent and non-fluorescent functional groups of cell colonies but captured Anabaena flos-aquae through the fluorescent ones. More Microcystis aeruginosa got membrane-damaged than Microcystis panniformis; nevertheless, the microcystin-LR (MC-LR) removal was guaranteed through efficiently oxidizing the released MC-LR. Although the outer peptidoglycan sheet of Anabaena flos-aquae was destroyed, the inner cyte membrane remained intact, preventing intracellular MC-LR from releasing. The HCBs dominated by single species with spherical cells were more readily treated than those with co-occurred species. The toxicological tests imply that, as a robust tool for HCB treatment, the CCOMB technology could be eco-environmentally friendly to the aquatic environment.

Removal of micron-scale microplastic particles from different waters with efficient tool of surface-functionalized microbubbles.

Microplastic (MP) contamination in water has garnered significantly global concerns. The MP removal particularly challenges when the particle size decreases to several microns and other contaminants co-exist. This study used the coagulative colloidal gas aphrons (CCGAs) to simultaneously remove the micron-scale MP particles (~5 µm in diameter) and dissolved organic matter (DOM). Carboxyl-modified poly-(methyl methacrylate) (PMMA) and unsurface-coated polystyrene (PS) were chosen as target MPs. Over 94% of PS particles and almost 100% of color were simultaneously removed with lower CCGA consumption than the scenarios with either contaminant in water. The PMMA removal was not as high as the PS removal since the HA polyanions could compete with the negatively-charged PMMA for CCGAs. High salinity reduced the removal of HA by changing its interfacial behaviors without impacting the MP separation. In river water or influent of wastewater treatment plant, the MP particles were almost completely eliminated whereas the DOM (tyrosine-like or tryptophan-like) was partially removed. The fluorescence quenching titration revealed that CCGAs preferably captured the free DOM and the DOM-coated MP particles through complexation interaction. The study denoted that the CCGA system could be a robust tool for efficiently and synergistically removing micron-scale MPs and DOM from different water matrixes.

TXNIP contributes to bone loss via promoting the mitochondrial oxidative phosphorylation during glucocorticoid-induced osteoporosis.

Oxidative stress is a promoting factor in the pathologic process of glucocorticoid - induced osteoporosis (GIO), while the mechanism is still unclear. Thioredoxin-interacting protein (TXNIP) is a vital protein responsible for regulation of cellular reactive oxygen species (ROS) generation elicited by mitochondrial oxidative stress, and which may activate oxidative phosphorylation under the pathogenic status. In this research, the results showed that signaling pathway associated with the mitochondrial oxidative phosphorylation (MOP) down-regulated under conditions of TXNIP siRNA in MG63 cells. Furthermore, the evidence revealed that the expression level of TXNIP in serum and bone was elevated in a rat of GIO. Moreover, the differential proteins (Ndufs3, SDHD, Cyt B, COX IV, and ATP B) related to MOP pathway were identified to down-regulate in the proteomics of bone tissues by using isobaric Tags for Relative and Absolute Quantification (iTRAQ) method in TXNIP knockout mice treated with glucocorticoid, and the proteins were also verified by simple western blot. Taken together, the present findings highlights that TXNIP involves in triggering the process of bone loss via up-regulation of the MOP pathway, resulting to GIO, while TXNIP knockout can prevent the pathogenesis of GIO to some extent.