HNGF6A Inhibits Oxidative Stress-Induced MC3T3-E1 Cell Apoptosis and Osteoblast Phenotype Inhibition by Targeting Circ_0001843/miR-214 Pathway.

Humanin (HN), a mitochondrial derived peptide, plays cyto-protective role under various stress. In this study, we aimed to investigate the effects of HNGF6A, an analogue of HN, on osteoblast apoptosis and differentiation and the underlying mechanisms. Cell proliferation of murine osteoblastic cell line MC3TC-E1 was examined by CCK8 assay and Edu staining. Cell apoptosis was detected by Annexin V assay under H2O2 treatment. The differentiation of osteoblast was determined by Alizarin red S staining. We also tested the expression of osteoblast phenotype related protein by real-time PCR and Western blot. The interaction between Circ_0001843 and miR-214, miR-214 and TAFA5 was examined by luciferase report assay. Circ_0001843 was inhibited by siRNA and miR-214 was suppressed by miR-214 inhibitor to determine the effects of Circ_0001843 and miR-214 on cell proliferation, apoptosis, and differentiation. HNGF6A, an analogue of HN, exerted cyto-protection and osteogenesis-promotion in MC3T3-E1 cells. The expression of osteoblast phenotype related protein was significantly induced by HNGF6A. Additionally, HNGF6A treatment decreased Circ_0001843 and increased miR-214 levels, as well as inhibited the phosphorylation of p38 and JNK. We further found that Circ_0001843 directly bound with miR-214, which in turn inhibited the phosphorylation of p38 and JNK. Furthermore, both Circ_0001843 overexpression and miR-214 knockdown significantly decreased the cyto-protection and osteogenic promotion of HNGF6A. In summary, our data showed that HNGF6A protected osteoblasts from oxidative stress-induced apoptosis and osteoblast phenotype inhibition by targeting Circ_0001843/miR-214 pathway and the downstream kinases, p38 and JNK.

A Randomized Clinical Trial of Intravenous Methylprednisolone With 2 Protocols in Patients With Graves Orbitopathy.

CONTEXT: Intravenous glucocorticoid (IVGC) is an accessible and affordable treatment for Graves orbitopathy (GO); the 4.5-g protocol is well studied, but many details of treatment protocols need to be clarified. OBJECTIVE: To compare the efficacy and safety of weekly and monthly protocol of IVGC in GO. METHODS: A prospective, randomized, observer-masked, single-center clinical trial, followed up to week 24, at the third affiliated hospital of Southern Medical University; 58 patients with active and moderate to severe GO, aged 18-60 years old, who had not received relevant treatment were included. The intervention was weekly protocol or monthly protocol of IVGC; both received a cumulative dose of methylprednisolone 4.5 g and had a duration of 12 weeks. The overall effective rate, improvement of quality of life (QOL) and signal intensity ratio (SIR) were measured. RESULTS: There was no significant difference in the effective rate between the 2 groups at week 12 and week 24 (86.21% vs 72.41%, P = .195; 86.21% vs 82.61%, P = .441), there was no significant difference in the improvement of clinical activity score, exophthalmos, soft tissue involvement, diplopia, and QOL. At week 24, the mean SIR and maximum SIR of the 2 groups were lower than those before treatment, and there were no statistically significant difference between the 2 groups. There was no significant difference in the incidence of adverse events between the 2 groups (31.03% vs 27.59%, P = .773). CONCLUSION: The efficacy and safety of the 2 protocols are comparable; the monthly protocol could be used as an alternative to the weekly protocol.

Gut microbiota impacts bone via Bacteroides vulgatus-valeric acid-related pathways.

Although the gut microbiota has been reported to influence osteoporosis risk, the individual species involved, and underlying mechanisms, remain largely unknown. We performed integrative analyses in a Chinese cohort of peri-/post-menopausal women with metagenomics/targeted metabolomics/whole-genome sequencing to identify novel microbiome-related biomarkers for bone health. Bacteroides vulgatus was found to be negatively associated with bone mineral density (BMD), which was validated in US white people. Serum valeric acid (VA), a microbiota derived metabolite, was positively associated with BMD and causally downregulated by B. vulgatus. Ovariectomized mice fed B. vulgatus demonstrated increased bone resorption and poorer bone micro-structure, while those fed VA demonstrated reduced bone resorption and better bone micro-structure. VA suppressed RELA protein production (pro-inflammatory), and enhanced IL10 mRNA expression (anti-inflammatory), leading to suppressed maturation of osteoclast-like cells and enhanced maturation of osteoblasts in vitro. The findings suggest that B. vulgatus and VA may represent promising targets for osteoporosis prevention/treatment.

Identification of PDXDC1 as a novel pleiotropic susceptibility locus shared between lumbar spine bone mineral density and birth weight.

An increasing number of epidemiological studies have suggested that birth weight (BW) may be a determinant of bone health later in life, although the underlying genetic mechanism remains unclear. Here, we applied a pleiotropic conditional false discovery rate (cFDR) approach to the genome-wide association study (GWAS) summary statistics for lumbar spine bone mineral density (LS BMD) and BW, aiming to identify novel susceptibility variants shared between these two traits. We detected 5 novel potential pleiotropic loci which are located at or near 7 different genes (NTAN1, PDXDC1, CACNA1G, JAG1, FAT1P1, CCDC170, ESR1), among which PDXDC1 and FAT1P1 have not previously been linked to these phenotypes. To partially validate the findings, we demonstrated that the expression of PDXDC1 was dramatically reduced in ovariectomized (OVX) mice in comparison with sham-operated (SHAM) mice in both the growth plate and trabecula bone. Furthermore, immunohistochemistry assay with serial sections showed that both osteoclasts and osteoblasts express PDXDC1, supporting its potential role in bone metabolism. In conclusion, our study provides insights into some shared genetic mechanisms for BMD and BW as well as a novel potential therapeutic target for the prevention of OP in the early stages of the disease development. KEY MESSAGES : We investigated pleiotropy-informed enrichment between LS BMD and BW. We identified genetic variants related to both LS BMD and BW by utilizing a cFDR approach. PDXDC1 is a novel pleiotropic gene which may be related to both LS BMD and BW. Elevated expression of PDXDC1 is related to higher BMD and lower ratio n-6/n-3 PUFA indicating a bone protective effect of PDXDC1.

Identification and Functional Characterization of Metabolites for Bone Mass in Peri- and Postmenopausal Chinese Women.

CONTEXT: Although metabolic profiles appear to play an important role in menopausal bone loss, the functional mechanisms by which metabolites influence bone mineral density (BMD) during menopause are largely unknown. OBJECTIVE: We aimed to systematically identify metabolites associated with BMD variation and their potential functional mechanisms in peri- and postmenopausal women. DESIGN AND METHODS: We performed serum metabolomic profiling and whole-genome sequencing for 517 perimenopausal (16%) and early postmenopausal (84%) women aged 41 to 64 years in this cross-sectional study. Partial least squares regression and general linear regression analysis were applied to identify BMD-associated metabolites, and weighted gene co-expression network analysis was performed to construct co-functional metabolite modules. Furthermore, we performed Mendelian randomization analysis to identify causal relationships between BMD-associated metabolites and BMD variation. Finally, we explored the effects of a novel prominent BMD-associated metabolite on bone metabolism through both in vivo/in vitro experiments. RESULTS: Twenty metabolites and a co-functional metabolite module (consisting of fatty acids) were significantly associated with BMD variation. We found dodecanoic acid (DA), within the identified module causally decreased total hip BMD. Subsequently, the in vivo experiments might support that dietary supplementation with DA could promote bone loss, as well as increase the osteoblast and osteoclast numbers in normal/ovariectomized mice. Dodecanoic acid treatment differentially promoted osteoblast and osteoclast differentiation, especially for osteoclast differentiation at higher concentrations in vitro (eg,10, 100 µM). CONCLUSIONS: This study sheds light on metabolomic profiles associated with postmenopausal osteoporosis risk, highlighting the potential importance of fatty acids, as exemplified by DA, in regulating BMD.

Umbilical Cord-Derived Mesenchymal Stem Cell-Derived Exosomes Combined Pluronic F127 Hydrogel Promote Chronic Diabetic Wound Healing and Complete Skin Regeneration.

PURPOSE: Chronic refractory wounds are a multifactorial comorbidity of diabetes mellitus with the characteristic of impaired vascular networks. Currently, there is a lack of effective treatments for such wounds. Various types of mesenchymal stem cell-derived exosomes (MSC-exos) have been shown to exert multiple therapeutic effects on skin regeneration. We aimed to determine whether a constructed combination of human umbilical cord MSC (hUCMSC)-derived exosomes (hUCMSC-exos) and Pluronic F-127 (PF-127) hydrogel could improve wound healing. MATERIALS AND METHODS: We topically applied human umbilical cord-derived MSC (hUCMSC)-derived exosomes (hUCMSC-exos) encapsulated in a thermosensitive PF-127 hydrogel to a full-thickness cutaneous wound in a streptozotocin-induced diabetic rat model. The material properties and wound healing ability of the hydrogel and cellular responses were analyzed. RESULTS: Compared with hUCMSC-exos, PF-127-only or control treatment, the combination of PF-127 and hUCMSC-exos resulted in a significantly accelerated wound closure rate, increased expression of CD31 and Ki67, enhanced regeneration of granulation tissue and upregulated expression of vascular endothelial growth factor (VEGF) and factor transforming growth factor beta-1 (TGFß-1). CONCLUSION: The efficient delivery of hUCMSC-exos in PF-127 gel and improved exosome ability could promote diabetic wound healing. Thus, this biomaterial-based exosome therapy may represent a new therapeutic approach for cutaneous regeneration of chronic wounds.

Conditional knockout of pyruvate dehydrogenase in mouse pancreatic ß­cells causes morphological and functional changes.

Diabetes mellitus is a metabolic disorder predominantly caused by the dysfunction of pancreatic ß­cells. This dysfunction is partly caused by the dysregulation of pyruvate dehydrogenase (PDH), which acts as an important mediator of pyruvate oxidation after glycolysis and fuels the tricarboxylic acid cycle. Previous studies have reported decreased PDH expression in rodent models and humans with type 2 diabetes mellitus (T2DM), suggesting that PDH may play an important role in the development of T2DM. However, the mechanism by which PDH affects insulin secretion and ß­cell development is poorly understood. Using immunofluorescence staining, the present study found that the expression of pyruvate dehydrogenase E1­α subunit (PDHA1; encoded by the PDHA1 gene) in the islets of type 2 diabetic mice (db/db mice) was lower than in wild­type mice, which indicated the possible association between PDHA1and diabetes. To further understand this mechanism, an inducible, islet­specific PDHA1 knockout mouse (ßKO) model was established. The phenotype was authenticated, and the blood glucose levels and islet function between the ßKO and control mice were compared. Though no changes were found in food intake, development status, fasting blood glucose or weight between the groups, the level of insulin secretion at 30 min after glucose injection in the ßKO group was significantly lower compared with the control group. Furthermore, the performed of the ßKO mice on the intraperitoneal glucose tolerance test was visibly impaired when compared with the control mice. Pancreatic tissues were collected for hematoxylin and eosin staining, immunohistochemical and confocal laser­scanning microscopy analysis. Examination of the islets from the ßKO mouse model indicated that abolishing the expression of PDH caused a compensatory islet enlargement and impaired insulin secretion.

[Prevalence of chronic kidney disease and its risk factors in subjects with different glucose metabolism status].

OBJECTIVE: To investigate the prevalence of chronic kidney disease (CKD) in subjects with different glucose metabolism status. METHODS: Between January, 2015 and October, 2015, a total of 934 subjects without a previous diagnosis of diabetes visiting the Department of Endocrinology or Health Examination Center underwent oral glucose tolerance test (OGTT), which identified 266 subjects with normal glucose tolerance (NGT group), 243 pre-diabetic subjects, and 425 patients with diabetes mellitus group. The baseline characteristics and laboratory test data of the subjects were collected. The diagnosis of CKD was established for an eGFR <60 mL/min/1.73 m(2) or a ACR≥30 mg/g, and the prevalence of CKD were compared among the 3 groups. Logistic regression model was used to analyze the OR value of the risk factors of CKD. RESULTS: The prevalences of CKD in NGT, pre-diabetic and diabetic groups were 10.2%, 26.3% and 32.5%, respectively. Pairwise comparisons showed that the prevalence of CKD was significantly higher in pre-diabetic group (P<0.001, OR=3.17, 95% CI 1.94-5.17) and diabetic group (P<0.001, OR=4.27, 95% CI 2.72-6.65) than in NGT group, and was comparable between the pre-diabetic and diabetic groups (P=0.115, OR=1.35, 95% CI 0.95-1.91). Logistic regression analysis, after adjustment for age, gender, blood pressure, hypertension, blood lipids and uric acid, showed that pre-diabetes (OR=2.03, P=0.044) and diabetes mellitus (OR=2.22, P=0.016) were independently associated with CKD. CONCLUSION: Glucose metabolism status has a significant independent impact on the incidence of CKD, suggesting the importance of early detection of pre-diabetes and timely interventions in pre-diabetic subjects in prevention CKD.

Integrative Analysis of Genomics and Transcriptome Data to Identify Potential Functional Genes of BMDs in Females.

Osteoporosis is known to be highly heritable. However, to date, the findings from more than 20 genome-wide association studies (GWASs) have explained less than 6% of genetic risks. Studies suggest that the missing heritability data may be because of joint effects among genes. To identify novel heritability for osteoporosis, we performed a system-level study on bone mineral density (BMD) by weighted gene coexpression network analysis (WGCNA), using the largest GWAS data set for BMD in the field, Genetic Factors for Osteoporosis Consortium (GEFOS-2), and a transcriptomic gene expression data set generated from transiliac bone biopsies in women. A weighted gene coexpression network was generated for 1574 genes with GWAS nominal evidence of association (p ≤ 0.05) based on dissimilarity measurement on the expression data. Twelve distinct gene modules were identified, and four modules showed nominally significant associations with BMD (p ≤ 0.05), but only one module, the yellow module, demonstrated a good correlation between module membership (MM) and gene significance (GS), suggesting that the yellow module serves an important biological role in bone regulation. Interestingly, through characterization of module content and topology, the yellow module was found to be significantly enriched with contractile fiber part (GO:044449), which is widely recognized as having a close relationship between muscle and bone. Furthermore, detailed submodule analyses of important candidate genes (HOMER1, SPTBN1) by all edges within the yellow module implied significant enrichment of functional connections between bone and cytoskeletal protein binding. Our study yielded novel information from system genetics analyses of GWAS data jointly with transcriptomic data. The findings highlighted a module and several genes in the model as playing important roles in the regulation of bone mass in females, which may yield novel insights into the genetic basis of osteoporosis. © 2016 American Society for Bone and Mineral Research.