ECM1-associated miR-1260b promotes osteogenic differentiation by targeting GDI1.

Osteoporosis (OP) is a common disease among older adults. The promotion of osteoblast differentiation plays a crucial role in alleviating OP symptoms. Extracellular matrix protein 1 (ECM1) has been reported to be closely associated with osteogenic differentiation. In this study, we constructed U2OS cell lines with ECM1 knockdown and ECM1a overexpression based on knockdown, and identified the target miRNA (miR-1260b) by sequencing. Overexpression of miR-1260b promoted the osteogenic differentiation of U2OS and MG63 cells, as demonstrated by increased alkaline phosphatase (ALP) activity, matrix mineralization, and Runt-Related Transcription Factor 2 (RUNX2), Osteopontin (OPN), Collagen I (COL1A1), and Osteocalcin (OCN) protein expressions, whereas low expression of miR-1260b had the opposite effect. In addition, miR-1260b expression was decreased in OP patients than in non-OP patients. Next, we predicted the target gene of miRNA through TargetScan and miRDB and found that miR-1260b negatively regulated GDP dissociation inhibitor 1 (GDI1) by directly binding to its 3'-untranslated region. Subsequent experiments revealed that GDI1 overexpression decreased ALP activity and calcium deposit, reduced RUNX2, OPN, COL1A1, and OCN expression levels, and reversed the effects of miR-1260b on osteogenic differentiation. In conclusion, ECM1-related miR-1260b promotes osteogenic differentiation by targeting GDI1 in U2OS and MG63 cells. Thus, this study has significant implication for osteoporosis treatment.

SOD3 regulates FLT1 to affect bone metabolism by promoting osteogenesis and inhibiting adipogenesis through PI3K/AKT and MAPK pathways.

Osteoporosis is a chronic disease that seriously affects the quality of life and longevity of the elderly, so exploring the mechanism of osteoporosis is crucial for drug development and treatment. Bone marrow mesenchymal stem cells are stem cells with multiple differentiation potentials in bone marrow, and changing their differentiation direction can change bone mass. As an extracellular superoxide dismutase, Superoxide Dismutase 3 (SOD3) has been proved to play an important role in multiple organs, but the detailed mechanism of action in bone metabolism is still unclear. In this study, the results of clinical serum samples ELISA and single cell sequencing chip analysis proved that the expression of SOD3 was positively correlated with bone mass, and SOD3 was mainly expressed in osteoblasts and adipocytes and rarely expressed in osteoblasts in BMSCs. In vitro experiments showed that SOD3 can promote osteogenesis and inhibit adipogenesis. Compared with WT mice, the mice that were knocked out of SOD3 had a significant decrease in bone mineral density and significant changes in related parameters. The results of HE and IHC staining suggested that knocking out SOD3 would lead to fat accumulation in the bone marrow cavity and weakened osteogenesis. Both in vitro and in vivo experiments indicated that SOD3 affects bone metabolism by promoting osteogenesis and inhibiting adipogenesis. The results of transcriptome sequencing and revalidation showed that SOD3 can affect the expression of FLT1. Through in vitro experiments, we proved that FLT1 can also promote osteogenesis and inhibit adipogenesis. In addition, through the repeated experiments, the interaction between the two molecules (SOD3 and FLT1) was verified again. Finally, it was verified by WB that SOD3 regulates FLT1 to affect bone metabolism through PI3K/AKT and MAPK pathways.

PDCD10 promotes proliferation, migration, and invasion of osteosarcoma by inhibiting apoptosis and activating EMT pathway.

BACKGROUND: Osteosarcoma, a common primary malignant tumor, occurs in children and adolescents with a poor prognosis. The current treatment methods are various, while the five-year survival rate of patients has not been significantly improved. As a member of the programmed death factor (PDCD) family, programmed death factor 10 (PDCD10) plays a role in regulating cell apoptosis. Several studies of PDCD10 in CCM and cancers have been reported before. However, there are no relevant research reports on the effects of PDCD10 on osteosarcoma. METHODS: We used bioinformatics analysis, IHC, and clinical data to confirm the expression of PDCD10 and its correlation with prognosis in osteosarcoma. Then, we used shRNAs and cDNA to knock down or overexpress PDCD10 in U2OS and MG63 cell lines. A series of function assays such as CCK8, Wound healing test, Plate cloning formation assay, and Transwell were done to confirm how PDCD10 affects osteosarcoma. Animal assays were done to confirm the conclusions in cell lines. At last, WB was used to measure the protein expression levels of apoptosis and the EMT pathway. RESULTS: PDCD10 was highly expressed in patients with osteosarcoma and correlated with prognosis; PDCD10 knockdown inhibited osteosarcoma growth, proliferation, migration, and invasion; PDCD10 overexpression promoted osteosarcoma growth, proliferation, migration, and invasion. In vivo experiments confirmed the conclusions in cell lines; PDCD10 inhibited apoptosis and activated the EMT pathway. CONCLUSIONS: In this study, it was found that PDCD10 was highly expressed in patients with osteosarcoma, and it was closely related to patient prognosis. PDCD10 inhibited tumor cell apoptosis and promoted tumor progression by activating the EMT pathway. These findings may provide a potential target for gene therapy of osteosarcoma.

Inhibition of CRY2 by STAT3/miRNA-7-5p Promotes Osteoblast Differentiation through Upregulation of CLOCK/BMAL1/P300 Expression.

Accumulating evidence indicates that cryptochrome circadian regulatory (CRY) proteins have emerged as crucial regulators of osteogenic differentiation. However, the associated mechanisms are quite elusive. In this study, we show that knockdown of CRY2 downregulated the expression of runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN) to facilitate osteoblast differentiation. Further study identified that CRY2 was directly targeted by microRNA (miR)-7-5p, which was highly induced during osteoblast differentiation. The expression of Runx2, ALP, collagen type I alpha 1 (Col1a1), and OCN was upregulated by overexpression of miR-7-5p and induction of osteoblast differentiation. Moreover, signal transducer and activator of transcription 3 (STAT3) transcriptionally activated miR-7-5p to significantly enhance the expression of above osteogenic marker genes and mineral formation. However, overexpression of CRY2 abolished the osteogenic differentiation induced by miR-7-5p overexpression. Silencing of CRY2 unraveled the binding of CRY2 with the circadian locomotor output cycles kaput (CLOCK)/brain and muscle ARNT-like 1 (BMAL1) complex to release CLOCK/BMAL1, which facilitated the binding of CLOCK/BMAL1 to the promoter region of the P300 E-box to stimulate the transcription of P300. P300 subsequently promoted the acetylation of histone 3 and the formation of a transcriptional complex with Runx2 to enhance osteogenesis. Taken together, our study revealed that CRY2 is repressed by STAT3/miR-7-5p to promote osteogenic differentiation through CLOCK/BMAL1/P300 signaling. The involved molecules may be potentially targeted for treatment of osteoporosis.

Prediction of success for polymerase chain reactions using the Markov maximal order model and support vector machine.

Polymerase chain reaction (PCR) is hailed as one of the monumental scientific techniques of the twentieth century, and has become a common and often indispensable technique in many areas. However, researchers still frequently find some DNA templates very hard to amplify with PCR, although many kinds of endeavors were introduced to optimize the amplification. In fact, during the past decades, the experimental procedure of PCR was always the focus of attention, while the analysis of a DNA template, the PCR experimental subject itself, was almost neglected. Up to now, nobody can certainly identify whether a fragment of DNA can be simply amplified using conventional Taq DNA polymerase-based PCR protocol. Characterizing a DNA template and then developing a reliable and efficient method to predict the success of PCR reactions is thus urgently needed. In this study, by means of the Markov maximal order model, we construct a 48-D feature vector to represent a DNA template. Support vector machine (SVM) is then employed to help evaluate PCR result. To examine the anticipated success rates of our predictor, jackknife cross-validation test is adopted. The overall accuracy of our approach arrives at 93.12%, with the sensitivity, specificity, and MCC of 94.68%, 91.58%, and 0.863%, respectively.