Significant amount of bone mass is lost during the process of aging due to an imbalance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption in bone marrow microenvironment, which leads to net bone loss in the aging population, resulting in the pathogenesis of osteoporosis. Firstly, differences in proliferative capacity of adipocyte or adipogenic differentiation in mouse mesenchymal stem cells (MMSCs) and senile mouse model-derived bone marrow mesenchymal stem cells (SMMSCs), as well as mRNA expression of OGN and PPARγ2 were observed. Secondly, osteogenic abilities of MMSCs and SMMSCs treated with rosiglitazone (a PPARγ2 agonist) to induce osteogenic changes were observed, and negative correlation of PPARγ2 with OGN was evaluated. Thirdly, the role of SMMSCs in promoting osteogenesis was examined through enhancing expression of OGN; besides, the related mechanism was investigated by means of expression of related adipocyte and osteoblast specific genes. Forced OGN expression by OGN-infected lentivirus could increase expression of Wnt5b, RUNX2, OCN, ALP and Colla1, as well as bone formation, while decreases expression of adipogenesis marker PPARγ2. It resulted in expression inhibition of adipocyte genes such as adipocytic differentiation related genes adipocyte binding protein 2 (aP2) and osteoclast differentiation factor Rankl in bone marrow, giving rise to increased bone mass. OGN may plays a significant role in osteoporosis, which may also provide a potential target for therapeutic intervention of senile osteoporosis characterized by altered differentiation of BMSCs into osteoblasts and adipocytes.

Congenital hypothyroidism (CH) is a common congenital endocrine disorder in humans. CH-related diseases such as athyreosis, thyroid ectopy, and hypoplasia are primarily caused by dysgenic thyroid development. However, the underlying molecular mechanisms remain unknown. To identify novel CH candidate genes, 192 CH patients were enrolled, and target sequencing of 21 known CH-related genes was performed. The remaining 98 CH patients carrying no known genes were subjected to exome sequencing (ES). The functions of the identified variants were confirmed using thyroid epithelial cells in vitro and in zebrafish model organisms in vivo. Four pathogenic GBP1 variations from three patients were identified. In zebrafish embryos, gbp1 knockdown caused defective thyroid primordium morphogenesis and hypothyroidism. The thyroid cells were stuck together and failed to dissociate from each other to form individual follicles in gbp1-deficient embryos. Furthermore, defects were restored with wild-type human GBP1 (hGBP1) messenger RNA (mRNA) except for mutated hGBP1 (p.H150Y, p.L187P) overexpression. GBP1 promoted β-catenin translocation into the cytosol and suppressed the formation of cellular adhesion complexes. Suppression of cell-cell adhesion restored the thyroid primordium growth defect observed in gbp1-deficient zebrafish embryos. This study provides further understanding regarding thyroid development and shows that defective cellular remodeling could cause congenital hypothyroidism.

Context Hashimoto’s thyroiditis (HT) and Graves’ disease (GD) are the two main autoimmune thyroid diseases with both similarities and differences. Determining the genetic basis that distinguishes HT from GD is key for a better understanding of the differences between these two closely related diseases. Objects&Design In the current study, 18 SNPs from 18 established GD risk loci were selected and then genotyped in 2,682 patients with HT, 4,980 patients with GD and 3,892 controls, The association analysis between HT and controls and heterogeneity analysis between HT and GD were performed on SPSS with the logistic regression analysis adjusted for sex and age. Results we identified 11 susceptibility loci for HT in the Chinese Han population, with four loci including the rs1265883 in SLAMF6 locus, rs1024161 in CTLA4, rs1521 in MHC–IB region and rs5912838 in GPR174/ ITM2A at X chromosome, reaching genome–wide significance of 5×10^–8. Five loci were reported to be associated with HT for the first time. We also identified six susceptibility loci with heterogeneity between GD and HT. Out of them, four loci were associated with GD, but not with HT including HLA–DPB1, CD40, TSHR and TG, and the association of HLA–B with GD was stronger than that with HT but the association of SLAMF6 was reversed. Conclusion Our findings suggested that the pathogenesis of HT and GD was different.

Background: Hashimoto’s thyroiditis (HT) is an autoimmune thyroid disease. Papillary thyroid carcinoma (PTC) is the most common endocrine cancer. In recent years the rate of coexistence between PTC and HT has increased but the relationship between them remains unclear, meaning it is necessary to find potential biomarkers for PTC coexistence with HT to predict its potential pathways.Method: A co-expression network was constructed using the weighted gene co-expression network analysis (WGCNA) in the R package. The modules of PTC associated with HT (PTC-W) were identified from the GSE138198 dataset. Protein-protein interaction network (PPI) was used to screen the hub genes. Immunohistochemical (IHC) analysis was performed to validate the expression of the hub genes in tissues. Clinical data from The Cancer Genome Atlas (TCGA) datasets were used to analyse the prognosis of the hub genes. Gene set enrichment analysis (GSEA) was used to screen potential pathways of PTC-W.Result: The MEbrown module representing the most significant module, with 958 differentially expressed genes (DEGs), was screened in PTC-W, based on WGCNA analysis. Through PPI, SERPINA1 was identified as a hub gene. Immunostaining validated that SERPINA1 was highly expressed in PTC-W. Moreover, PTC-W expressing SERPINA1 exhibits a better prognosis than PTC without HT (PTC-WO).Conclusion: Our study demonstrates that SERPINA1 promotes the occurrence of PTC-W, and its prognosis is better than PTC-WO. SERPINA1 promotes a better prognosis for PTC-W, possibly through a tumour inhibition signalling pathway.

Background: Congenital hypothyroidism (CH) is the most common neonatal metabolic disorder. In patients with CH in China, thyroid dyshormonogenesis is more common than thyroid dysgenesis; however, the genetic causes of CH due to thyroid dyshormonogenesis remain largely unknown. Therefore, we aimed at identifying novel candidate causative genes for CH. Methods: To identify novel CH candidate genes, a total of 599 patients with CH were enrolled and next-generation sequencing was performed. The functions of the identified variants were confirmed using HEK293T and FTC-133 cell lines in vitro and in a mouse model organism in vivo . Results: Three pathogenic contactin 6 ( CNTN6 ) variants were identified in two patients with CH. Pedigree analysis showed that CH caused by CNTN6 variants was inherited in an autosomal recessive pattern. The CNTN6 gene was highly expressed in the thyroid in humans and mice. Cntn6 knockout mice presented with thyroid dyshormonogenesis and CH due to the decreased expression of crucial genes for thyroid hormone biosynthesis ( Slc5a5 , Tpo , and Duox2 ). All three CNTN6 variants resulted in the blocking of the release of the Notch intracellular domain, which could not translocate into the nucleus, impaired NOTCH1 transcriptional activity, and decreased expression of SLC5A5 , TPO , and DUOX2 . Further, we found that DTX1 was required for CNTN6 to promote thyroid hormone biosynthesis through Notch signaling. Conclusions: This study demonstrated that CNTN6 is a novel causative gene for CH through the mediation of thyroid hormone biosynthesis via Notch signaling, which provides new insights into the genetic background and mechanisms involved in CH and thyroid dyshormonogenesis.