Integrative analysis of genomic and epigenomic data reveal underlying superenhancer-mediated microRNA regulatory network for human bone mineral density.

Bone mineral density (BMD) is a highly heritable complex trait and is a key indicator for diagnosis and treatment for osteoporosis. In the last decade, numerous susceptibility loci for BMD and fracture have been identified by genome-wide association studies (GWAS); however, fine mapping of these loci is challengeable. Here, we proposed a new long-range fine-mapping approach that combined superenhancers (SEs) and microRNAs (miRNAs) data, which were two important factors in control of cell identity and specific differentiation, with the GWAS summary datasets in cell-type-restricted way. Genome-wide SE-based analysis found that the BMD-related variants were significantly enriched in the osteoblast SE regions, indicative of potential long-range effects of such SNPs. With the SNP-mapped SEs (mSEs), 13 accessible long-range mSE-interacted miRNAs (mSE-miRNAs) were identified by integrating osteoblast Hi-C and ATAC-seq data, including three known bone-related miRNAs (miR-132-3p, miR-212-3p and miR-125b-5p). The putative targets of the two newly identified mSE-miRNAs (miR-548aj-3p and miR-190a-3p) were found largely enriched in osteogenic-related pathway and processes, suggesting that these mSE-miRNAs could be functional in the regulation of osteoblast differentiation. Furthermore, we identified 54 genes with the long-range 'mSE-miRNA' approach, and 24 of them were previously reported to be related to skeletal development. Besides, enrichment analysis found that these genes were specifically enriched in the post-transcriptional regulation and bone formation processes. This study provided a new insight into the approach of fine-mapping of GWAS loci. A tool was provided for the genome-wide SE-based analysis and the detection of long-range osteoblast-restricted mSE-miRNAs (https://github.com/Zheng-Lab-Westlake/Osteo-Fine-Mapp-SNP2SE2miRNA).

General and abdominal obesity operate differently as influencing factors of fracture risk in old adults.

To infer the causality between obesity and fracture and the difference between general and abdominal obesity, a prospective study was performed in 456,921 participants, and 10,142 participants developed an incident fracture with follow-up period of 7.96 years. A U-shape relationship was observed between BMI and fracture, with the lowest risk of fracture in overweight participants. The obesity individuals had higher fracture risk when BMD was adjusted, and the protective effect of moderate-high BMI on fracture was mostly mediated by bone mineral density (BMD). However, for abdominal obesity, the higher WCadjBMI (linear) and HCadjBMI (J-shape) were found to be related to higher fracture risk, and less than 30% of the effect was mediated by BMD. By leveraging genetic instrumental variables, it provided additional evidences to support the aforementioned findings. In conclusion, keeping moderate-high BMI might be of benefit to old people in terms of fracture risk, whereas abdominal adiposity might increase risk of fracture.

Characterization of multidrug­resistant osteosarcoma sublines and the molecular mechanisms of resistance.

Multidrug resistance (MDR) is a challenge for the treatment of cancer and the underlying molecular mechanisms remain elusive. The current study exposed MG63 osteosarcoma cells to increasing concentrations of vincristine (VCR) to establish four VCR­resistant MG63/VCR cell sublines (MG63/VCR1, 2, 3 and 4). The drug resistance indices (RI) of these sublines was detected with the CCK­8 assay and determined to be163, 476, 1,247, and 2,707­fold higher than that of parental cells, respectively. These sublines also exhibited cross­resistance to doxorubicin, paclitaxel and pirarubicin. With increased RI, the proliferative capacity of these sublines was gradually reduced and cell morphology was also altered, characterized by increased formation of pseudopodia and long cytoplasmic processes at opposite poles. However, the migration capacity and expression of certain drug resistance­associated genes were not in accordance with the increased RI; multidrug resistance protein 1 (MDR1) expression was significantly increased in these sublines compared with parental cells. However, in the highly resistant MG63/VCR3 and MG63/VCR4 cells, MDR­associated protein 1, topoisomerase II and LIM domain kinase 1 levels were significantly reduced compared with the moderately resistant MG63/VCR2 cells. Expression of glutathione S­transferase­π mRNA was determined using reverse transcription­quantitative polymerase chain reaction and determined that it was not changed between MG63 and MG63/VCR cells. The data of the present study demonstrated that the molecular alterations of drug resistance may change with the degree of drug resistance. Taking cell morphology into consideration, the intratumor clonal and phenotypic heterogeneity may be responsible for drug resistance. These MG63/VCR sublines may be a valuable tool to assess drug resistance and the underlying mechanisms, and to identify novel drug resistance­associated genes or strategies to overcome MDR in human osteosarcoma.

The influence of vitrectomies on the blood supply of the eyeball in patients with rhegmatogenous retinal detachment / 天津医药

Objective To analyse the retrobulbar haemodynamic changes after vitrectomy in patients with rhegmatogenous retinal detachment (RRD). Methods Color Doppler flow imaging (CDFI) was used for measurement of blood flow velocities including peak systolic velocity (PSV), end diastolic velocity (EVD) and resistive indexes (RI) of the ophthalmic artery (OA), posterior ciliary arteries (sPCA) and central retinal artery (CRA) in 50 eyes of 50 patients with RRD. In them 22 eyes were filled with silicone oil, 28 eyes were filled with 12%C3F8 and 22 eyes were operated to remove silicone oil after filled with silicone oil for 2-4 months, and then CDFI parameters were obtained. The contralateral eyes were used as control eyes before and after the operation. Results There were no significant differences in CRA and sPCA, and PSV, EDV and RI before treatment between RD and OA eyes and control eyes (P>0.05). PSV and EVD of CRA were significantly increased 3 months after surgery, RI were decreased significantly (P<0.05). There were no significant differences in blood flow parameters of OA and sPCA before and after surgeries (P>0.05). No changes were found in control eyes 3 months after surgery. Conclusion VRS might increase the velocity of CRA, decrease RI and improve ocular blood supply postoperatively.

Analysis of the key networks, metabolic pathways, and regulation substances of hypoxia based on the omics and zebrafish model / 中国药理学与毒理学杂志

OBJECTIVE Hypoxia is associated with many complicated pathophysiological and biochemical processes that integrated and regulated via the key gene, protein and endogenous metabolite levels. Up to date, the exact molecular mechanism of hypoxia still remains unclear. In this work, we further explore the molecular mechanism of hypoxia and adaption to attenuate the damage in zebrafish model that have potential to resist hypoxic environment. METHODS The hypoxic zebrafish model was established in different concentration of oxygen with 3%,5%,10%,21% in water. The brain tissue was separated and the RNA-seq was used to identify the differentially expressed genes. The related endogenous metabolites profiles were obtained by LC-HDMS, and the multivariate statistics was applied to discover the important metabolites candidates in hypoxic zebrafish. The candidates were searched in HMDB, KEGG and Lipid Maps databases. RESULTS The zebrafish hypoxic model was successfully constructed via the different concentration of oxygen, temperature and hypoxic time. The activities of the related hypoxic metabolic enzymes and factors including HIF-1a, actate dehydrogenase (LDH) and citrate synthase (CS) were evaluated. Significant differences (P<0.05 and fold change >2) in the expression of 422 genes were observed between the normal and 3% hypoxic model. Among them, 201 genes increased depended on the lower concentration of oxygen. 53 metabolites were identified that had significant difference between the hypoxia and control groups (P<0.05, fold change>1.5 and VIP>1.5). The ten key metabolites were increased gradually while six compounds were decreased. The endogenous hypoxic metabolites of phenylalanine, D-glucosamine-6P and several important lipids with the relevant hub genes had similar change in hypoxic model. In addition, the metabolic pathways of phenylalanine, glutamine and glycolipid were influenced in both the levels of genes and metabolites. CONCLUSION The up- regulation of phenylalanine, D- glucosamine- 6P and lipid may have further understanding of protective effect in hypoxia. Our data provided an insight to further reveal the hypoxia and adaptation mechanism.

The influence of vitrectomies on the blood supply of the eyeball in patients with rhegmatogenous retinal detachment / 天津医药

Objective To analyse the retrobulbar haemodynamic changes after vitrectomy in patients with rhegmatogenous retinal detachment (RRD). Methods Color Doppler flow imaging (CDFI) was used for measurement of blood flow velocities including peak systolic velocity (PSV), end diastolic velocity (EVD) and resistive indexes (RI) of the ophthalmic artery (OA), posterior ciliary arteries (sPCA) and central retinal artery (CRA) in 50 eyes of 50 patients with RRD. In them 22 eyes were filled with silicone oil, 28 eyes were filled with 12%C3F8 and 22 eyes were operated to remove silicone oil after filled with silicone oil for 2-4 months, and then CDFI parameters were obtained. The contralateral eyes were used as control eyes before and after the operation. Results There were no significant differences in CRA and sPCA, and PSV, EDV and RI before treatment between RD and OA eyes and control eyes (P>0.05). PSV and EVD of CRA were significantly increased 3 months after surgery, RI were decreased significantly (P<0.05). There were no significant differences in blood flow parameters of OA and sPCA before and after surgeries (P>0.05). No changes were found in control eyes 3 months after surgery. Conclusion VRS might increase the velocity of CRA, decrease RI and improve ocular blood supply postoperatively.