HuR-positive stress granules: Potential targets for age-related osteoporosis.

Aging impairs osteoblast function and bone turnover, resulting in age-related bone degeneration. Stress granules (SGs) are membrane-less organelles that assemble in response to stress via the recruitment of RNA-binding proteins (RBPs), and have emerged as a novel mechanism in age-related diseases. Here, we identified HuR as a bone-related RBP that aggregated into SGs and facilitated osteogenesis during aging. HuR-positive SG formation increased during osteoblast differentiation, and HuR overexpression mitigated the reduction in SG formation observed in senescent osteoblasts. Moreover, HuR positively regulated the mRNA stability and expression of its target ß-catenin by binding and recruiting ß-catenin into SGs. As a potential therapeutic target, HuR activator apigenin (API) enhanced its expression and thus aided osteoblasts differentiation. API treatment increased HuR nuclear export, enhanced the recruitment of ß-catenin into HuR-positive SGs, facilitated ß-catenin nuclear translocation, and contributed osteogenesis. Our findings highlight the roles of HuR and its SGs in promoting osteogenesis during skeletal aging and lay the groundwork for novel therapeutic strategies against age-related skeletal disorders.

Ellagic acid inhibits CDK12 to increase osteoblast differentiation and alleviate osteoporosis in hindlimb-unloaded and ovariectomized mice.

BACKGROUND: Osteoporosis is a highly prevalent bone disease occurred commonly in astronauts and postmenopausal women due to mechanical unloading and estrogen deficiency, respectively. At present, there are some traditional Chinese medicine compounds for preventing and treating osteoporosis induced by simulated microgravity, but the detailed components of the traditional Chinese medicines still need to be confirmed and osteoporosis is still untreatable due to a lack of effective small-molecule natural medicine. PURPOSE: To explore the role of cyclin-dependent kinase 12 (CDK12) in osteoporosis induced by simulated microgravity and the therapeutic effect of CDK12-targeted Ellagic Acid (EA) on osteoporosis. METHODS: Our previous study has suggested that CDK12 as a potential target for treating and preventing osteoporosis. In this study, the role of CDK12 in osteoblasts and mice bone tissues was further studied under simulated microgravity. And by targeting CDK12, natural small-molecule product EA was screened out based on a large scale through the weighted set similarity (WES) method and the therapeutic effects of EA on osteoporosis was investigated in hindlimb-unloaded (HU) mouse model and ovariectomized (OVX) model. RESULTS: The results demonstrated that simulated microgravity inhibited bone formation and up-regulated the expression of CDK12. Furthermore, CDK12-siRNA or THZ531 (an inhibitor of CDK 12) promoted osteoblast differentiation, while the overexpression of CDK12 inhibited osteoblasts differentiation. And we further proved that CDK12-targeted EA showed a rescue effect on osteoblast differentiation inhibition caused by simulated microgravity. EA (50 mg·kg-1·day-1) daily intragastric administration alleviated the symptoms of osteoporosis and accompanied with the improvement of trabecular bone and cortical bone parameters with significantly overexpression of CDK12. CONCLUSION: EA efficiently improves osteoporosis by targeting CDK12, which is a suppresser of osteoblast differentiation and a novel therapeutic target for treating osteoporosis.

Liquid-Liquid Phase Separation of Biomacromolecules and Its Roles in Metabolic Diseases.

Liquid-liquid phase separation (LLPS) compartmentalizes and concentrates biomacromolecules into liquid-like condensates, which underlies membraneless organelles (MLOs) formation in eukaryotic cells. With increasing evidence of the LLPS concept and methods, this phenomenon as a novel principle accounts for explaining the precise spatial and temporal regulation of cellular functions. Moreover, the phenomenon that LLPS tends to concentrate proteins is often accompanied by several abnormal signals for human diseases. It is reported that multiple metabolic diseases are strongly associated with the deposition of insoluble proteinaceous aggregating termed amyloids. At present, recent studies have observed the roles of LLPS in several metabolic diseases, including type 2 diabetes mellitus (T2DM), Alzheimer's disease (AD), and metabolic bone diseases (MBDs). This review aims to expound on the current concept and methods of LLPS and summarize its vital roles in T2DM, AD, and MBDs, uncover novel mechanisms of these metabolic diseases, and thus provide powerful potential therapeutic strategies and targets for ameliorating these metabolic diseases.

MiR-138-5p Targets MACF1 to Aggravate Aging-related Bone Loss.

Senile osteoporosis is one of the major health problems in an aging society. Decreased bone formation due to osteoblast dysfunction may be one of the causes of aging-related bone loss. With increasing evidence suggesting that multiple microRNAs (miRNAs) play important roles in osteoblast function, the relationship between miRNAs and senile osteoporosis has become a popular research topic. Previously, we confirmed that mechanoresponsive miR-138-5p negatively regulated bone anabolic action. In this study, the miR-138-5p level was found to be negatively correlated with BMD and osteogenic markers in bone specimens of senile osteoporotic patients by bioinformatic analysis and experimental verification. Furthermore, high miR-138-5p levels aggravated the decrease of aged osteoblast differentiation in vitro and led to worse bone loss in aged osteoblastic miR-138-5p transgenic mice in vivo. We also previously identified that the target of miR-138-5p, microtubule actin cross-linking factor 1 (MACF1), could attenuate senile osteoporosis. Here, miR-138-5p was demonstrated to regulate aged osteoblast differentiation by targeting MACF1. Finally, the therapeutic inhibition of miR-138-5p counteracted the decrease in bone formation and aging-related bone loss in aged mice. Overall, our results highlight the crucial roles and the molecular mechanism of miR-138-5p in aging-related bone loss and may provide a powerful therapeutic target for ameliorating senile osteoporosis.

Calycosin prevents bone loss induced by hindlimb unloading.

Bone loss induced by microgravity exposure seriously endangers the astronauts' health, but its countermeasures still have certain limitations. The study aims to find potential protective drugs for the prevention of the microgravity-induced bone loss. Here, we utilized the network pharmacology approach to discover a natural compound calycosin by constructing the compound-target interaction network and analyzing the topological characteristics of the network. Furthermore, the hind limb unloading (HLU) rats' model was conducted to investigate the potential effects of calycosin in the prevention of bone loss induced by microgravity. The results indicated that calycosin treatment group significantly increased the bone mineral density (BMD), ameliorated the microstructure of femoral trabecular bone, the thickness of cortical bone and the biomechanical properties of the bone in rats, compared that in the HLU group. The analysis of bone turnover markers in serum showed that both the bone formation markers and bone resorption markers decreased after calycosin treatment. Moreover, we found that bone remodeling-related cytokines in serum including IFN-γ, IL-6, IL-8, IL-12, IL-4, IL-10 and TNF-α were partly recovered after calycosin treatment compared with HLU group. In conclusion, calycosin partly recovered hind limb unloading-induced bone loss through the regulation of bone remodeling. These results provided the evidence that calycosin might play an important role in maintaining bone mass in HLU rats, indicating its promising application in the treatment of bone loss induced by microgravity.

Piezo Channels: Awesome Mechanosensitive Structures in Cellular Mechanotransduction and Their Role in Bone.

Piezo channels are mechanosensitive ion channels located in the cell membrane and function as key cellular mechanotransducers for converting mechanical stimuli into electrochemical signals. Emerged as key molecular detectors of mechanical forces, Piezo channels' functions in bone have attracted more and more attention. Here, we summarize the current knowledge of Piezo channels and review the research advances of Piezo channels' function in bone by highlighting Piezo1's role in bone cells, including osteocyte, bone marrow mesenchymal stem cell (BM-MSC), osteoblast, osteoclast, and chondrocyte. Moreover, the role of Piezo channels in bone diseases is summarized.

Analysis of syphilis antibody results in pregnant women and newborns detected by automatic chemiluminescent immunoassay / 中华检验医学杂志

Objective:To examine the distribution of syphilis antibody in pregnant women and newborns and to explore how to optimize the existing syphilis screening process by setting the diagnostic gray area.Methods:The results of syphilis testing obtained from 119 531 pregnant women and 21 275 newborns from 2015 to 2018 by automatic chemiluminescent immunoassay (CLIA) and the re-examination results determined by Treponema pallidum particle agglutination (TPPA) and the rapid plasma reagin test (RPR) were retrospective analyzed. Data analysis was performed by Chi-square, Fisher′s exact test and Chi-square test for trend. Results:The positive rates of Syphilis specific antibody (TPAb) in clinical specimens from pregnant women and newborns were 0.69% (825/119 531) and 1.24%(264/21 275). The total re-examination positive rates were 0.32% (380/119 531) and 0.90%(191/21 275), and the suspicious syphilis prevalence rates in these specimens were 0.13% (161/119 531) and 0.31%(67/21 275), respectively. The suspicious syphilis prevalence rates in specimens of pregnant women from 2015 to 2018 and newborns increased year by year (χ 2=9.860, P=0.002; χ 2=5.311, P=0.021). With the elevation of the optical density value of samples to cut-off ratio (S/CO) value, positive coincidence rate of TPPA and TPAb in pregnant women and newborns increased significantly (χ 2=614.833, P<0.001; P<0.001). When the S/CO value in newborns exceeded 7.00 or the S/CO value in pregnant women exceeded 15.00, the effectiveness of TPAb results is equivalent to TPPA. The prevalence of suspected syphilis in pregnant women and newborns also increased with the increase of S/CO value (χ 2=323.059, P<0.001; P<0.001). When the S/CO value in newborns bellowed 3.00 or the S/CO value in pregnant women bellowed 5.00, the prevalence rate of suspected syphilis was 0%, which could preliminarily exclude syphilis infection. Conclusions:The prevalence rates of suspected syphilis in pregnant women was increasing during the recent years. It is necessary to further strengthen syphilis screening and intervention treatment in early pregnancy to improve the rate of eugenics. Being a primary screening method for syphilis in pregnant women and newborns, CLIA has high false positive rate. According to the gray area established in this study, the syphilis screening process can be optimized to prevent missed detection, which may reduce the false positive rate and avoid clinical misdiagnosis.

Indicatory bacteria and chemical composition related to sulfur distribution in the river-lake systems.

Sulfate related water quality and trophic status are crucial to operation of water diversion. Though the sulfur geochemistry in the lake sediment have been well studied, the effective indicator of surrounding environment conditions related to sulfur in river-lake systems are still unknown. In this study, Dongping Lake (DPH), Weishan Lake (WSH), and Hanzhuang trunk canal (HZQ) were selected as the typical river-lake systems in the eastern of China. Different spatial variations in sedimentary sulfate, total sulfur, and elemental composition of sediments were investigated in these areas. The relatively high sulfate in surface water and sediments appeared in portions of WSH. The biodiversity of HZQ and WSH surface sediments was much higher than that of DPH. Pseudomonas, Acinetobacter, and Thiobacillus were the dominant genera of the river-lake systems. Among the different genera in distribution, genera such as Malikia, Sulfurovum and Lysinibacillus were significantly negatively correlated with sulfur related environmental factors. While the genera such as Pseudomonas, Vogesella and Acinetobacter were significantly positively correlated with these factors. Compared with connectivity in the largest interaction network, bacteria such as Proteus, Acidobacter and Chlorobacteria were identified as indicatory taxa to infer sulfate related conditions in the river-lake systems.

Mechanism of Yupingfeng Granule on CU Rats Based on IL-23/IL-17 Inflammation Axis / 中国实验方剂学杂志

Objective::To study the effect of Yupingfeng granule on the degranulation of skin mast cells in chronic urticaria (CU) rats and the intervention mechanism of interleukin-23(IL-23), interleukin-17(IL-17) inflammation axis. Method::Totally 60 SPF SD rats were selected and randomly divided into normal group (normal saline), model group (normal saline), and loratadine group (0.9 mg·kg-1·d-1), high-dose Yupingfeng granules group (4.05 g·kg-1·d-1), middle-dose group (2.7 g·kg-1·d-1), low-dose group (1.35 g·kg-1·d-1). The CU rat model was reproduced through intraperitoneal injection of ovalbumin with aluminum hydroxide suspension and DTP vaccine. Histopathological changes of rat skin were observed by hematoxylin-eosin (HE) staining. Degranulation of mast cells in rat skin was determined by toluidine blue staining. IL-23 and IL-17 protein expressions in skin tissue were determined by immunohistochemistry (IHC). IL-23 and IL-17 mRNA transcription levels in skin tissue were determined by real-time fluorescence quantitative polymerase chain reaction (Real-time PCR). Result::Yupingfeng granules can significantly alleviate the pathological manifestations of dermal edema, collagen beam distance, inflammatory cell infiltration of CU rats, and reduce the degranulation reaction of skin tissue mast cells in CU rats. The IL-23, IL-17 mRNA and protein expressions of the skin of model group were significantly increased compared with the normal group (P<0.05, P<0.01). Compared with the model group, Yupingfeng granules can significantly down-regulate IL-23 mRNA and protein expressions of CU rats (P<0.05, P<0.01). Yupingfeng granules had no significant regulatory effect on IL-17. Conclusion::Yupingfeng granule can significantly reduce the degranulation of mast cells in skin tissue of CU rats, and improve the pathological manifestations, such as dermal edema, serous exudation and inflammatory cell infiltration. The mechanism may be related to inhibiting the secretion of IL-23 pro-inflammatory cytokines and improving CU lesions.

167.75-nm vacuum-ultraviolet ps laser by eighth-harmonic generation of a 1342-nm Nd:YVO4 amplifier in KBBF.

We demonstrate a ps 167.75-nm vacuum-ultraviolet (VUV) laser by cascaded second-harmonic generation (SHG). The VUV laser is produced by eighth-harmonic generation (EHG) of a mode-locked ps 1342-nm Nd:YVO4 amplifier through three stages cascaded SHG with two LiB3O5 crystals and one KBe2BO3F2 crystal, successively. The 167.75-nm laser provides up to 65-µW output power, and the corresponding photon flux and photon flux density are 5.5×10(13) s(-1) and 1.6×10(18) s(-1)·cm(-2), respectively.