ERα/ß/DMP1 axis promotes trans-differentiation of chondrocytes to bone cells through GSK-3ß/ß-catenin pathway.

Estrogen-induced premature closing of the growth plate in the long bones is a major cause of short stature after premature puberty. Recent studies have found that chondrocytes can directly trans-differentiate into osteoblasts in the process of endochondral bone formation, which indicates that cartilage formation and osteogenesis may be a continuous biological process. However, whether estrogen promotes the direct trans-differentiation of chondrocytes into osteoblasts remains largely unknown. Chondrocytes were treated with different concentrations of 17ß-estradiol, and Alizarin Red staining and alkaline phosphatase activity assay were used to detected osteogenesis. Specific short hairpin RNA and tamoxifen were used to block the estrogen receptor (ER) pathway and osteogenic marker genes and downstream gene expression were detected using real-time quantitative polymerase chain reaction, western blot, and immunohistochemistry staining. The findings showed that 17ß-estradiol promoted the chondrocyte osteogenesis in vitro, even at high concentrations. In addition, blocking of the ERα/ß pathway inhibited the trans-differentiation of chondrocytes into osteogenic cells. Furthermore, we found that dentin matrix protein 1 (DMP1), which is a direct downstream molecular of ER, was involved in 17ß-estradiol/ER pathway-regulated osteogenesis. As well, glycogen synthase kinase-3 beta (GSK-3ß)/ß-catenin signal pathway also participates in ERα/ß/DMP1-regulated chondrocyte osteogenesis. The GSK-3ß/ß-catenin signal pathway was involved in ERα/ß/DMP1-regulated chondrocyte osteogenesis. These findings suggest that ER/DMP1/GSK-3ß/ß-catenin plays a vital role in estrogen regulation of chondrocyte osteogenesis and provide a therapeutic target for short stature caused by epiphyseal fusion.

Rapid discovery of natural antioxidants in Hypericum japonicum: Dual roles of the liquid phase mobile phase as extraction and separation solvent.

Hypericum japonicum is a traditional folk medicine with various bioactivities such as hepatoprotective, antioxidant, and anti-tumorous. The antioxidant effect of H. japonicum is one of the most prominent effects due to its responsibility for many of its activities. To clarify active natural substance, the antioxidant properties of H. japonicum were preliminarily assessed by ferric reducing-antioxidant power (FRAP), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and Oxygen radical absorbance capacity (ORAC), as well as superoxide dismutase (SOD). Then, a straightforward and effective method named online liquid extraction-high performance liquid chromatography combined with ABTS antioxidant assay and mass spectrometry (OLE-HPLC-ABTS/Q-TOF-MS) was developed to swiftly and directly discover the antioxidants in H. japonicum. Using mobile phase as extraction and separation reagent, coupled with online activity analysis and compounds identification by high-resolution MS, the online system enables rapid screening of natural antioxidant bioactives from complex mixture. By using it, a total of 9 compounds including flavonoids and phenolic acids characterized by retention time, precise mass, and fragmentation ions in MS/MS spectra showed antioxidant action. Finally, the antioxidant and SOD activity of main found active compounds were validated by in vitro experiment assay and molecular docking. In summary, these results suggested that H. japonicum could be considered as a potential source of natural antioxidants, and the online integrated system might become a promising candidate for the natural antioxidants discovery in the future.

Comparison of pharmacokinetic profiles in hypoalbuminemia and healthy rats after parecoxib sodium injection by LC-MS/MS.

Background: Valdecoxib is an active metabolite of parecoxib that has a high binding rate with plasma protein. Hypoalbuminemia may affect the pharmacokinetics process of valdecoxib. Method & results: A rapid LC-MS/MS method was applied to assay parecoxib and valdecoxib in hypoalbuminemia and healthy rats. Hypoalbuminemia rat models were established by intravenous injection of doxorubicin. The maximum plasma concentration and area under the curve values of valdecoxib in control and model groups were 744.04 ± 128.24 ng/ml, 152,727.87 ± 39,131.36 ng/ml·min and 234.25 ± 77.36 ng/ml, 29,032.42 ± 5116.62 ng/ml·min after 7.2 mg/kg parecoxib sodium injection and 371.95 ± 64.12 ng/ml, 62,218.25 ± 6876.93 ng/ml·min and 153.41 ± 33.17 ng/ml, 18,245.62 ± 868.53 ng/ml·min after 3.6 mg/kg parecoxib sodium injection, respectively. Conclusion: Hypoalbuminemia increases clearance and reduces the plasma concentration of valdecoxib in rats.

[Pharmacokinetic profiles of antifungal drugs during extracorporeal membrane oxygenation life support].

Extracorporeal membrane oxygenation (ECMO), a kind of life support technology that can replace lung and heart function, is widely used in critical respiratory and circulatory exhaustion. Because of the serious diseases and the use of interventional catheters, patients receiving ECMO life support are often administrated with broad-spectrum antimicrobial agents, which increase the risk of fungal infection. Fungal infection during ECMO can increase mortality. How to effectively control fungal infection is a thorny problem faced by clinicians. During the treatment of ECMO, the patient's physiological status, ECMO oxygenation membrane, circulation pipeline and other factors may change the pharmacokinetic profiles of antifungal drugs, thereby affect the clinical efficacy of drugs. This artical reviews the pharmacokinetic characteristics of antifungal drugs during ECMO support, in order to provide references for clinical antifungal treatment.