A New Method Used to Enhance the SPAIR Image of the Spine MRI.

BACKGROUND: Magnetic resonance imaging (MRI) is a handy diagnostic tool for orthopedic disorders, particularly spinal and joint diseases. METHODS: The lumbar intervertebral disc is visible in the T1 and T2 weight sequences of the spine MRI, which aids in diagnosing lumbar disc herniation, lumbar spine tuberculosis, lumbar spine tumors, and other conditions. The lumbar intervertebral disc cannot be seen accurately in the Spectral Attenuated Inversion Recovery (SPAIR) due to weaknesses in the fat and frequency offset parameters, which is not conducive to developing the intelligence diagnosis model of medical image. RESULTS: In order to solve this problem, we propose a composite framework, which is first to use the contrast limited adaptive histogram equalization (CLAHE) method to enhance the SPAIR image contrast of the spine MRI and then use the non-local means method to remove the noise of the image to ensure that the image contrast is uniform without losing details. We employ the Information Entropy (IE), Peak signal-to-noise ratio (PSNR), and feature similarity index measure (FSIM) to quantify image quality after enhancement by the composite framework. CONCLUSION: The outcomes of the experiments' output images and quantitative data indicate that our composite framework is better than others.

MiRNA320a Inhibitor-Loaded PLGA-PLL-PEG Nanoparticles Contribute to Bone Regeneration in Trauma-Induced Osteonecrosis Model of the Femoral Head.

BACKGROUND: This study aimed to explore the effect of a nanomaterial-based miR-320a inhibitor sustained release system in trauma-induced osteonecrosis of the femoral head (TIONFH). METHODS: The miR-320a inhibitor-loaded polyethylene glycol (PEG)- Poly(lactic-co-glycolic acid) (PLGA)- Poly-L-lysine (PLL) nanoparticles were constructed using the double emulsion method. The TIONFH rabbit model was established to observe the effects of miR-320a inhibitor nanoparticles in vivo. Hematoxylin-eosin staining and microcomputed tomography scanning were used for bone morphology analysis. Bone marrow mesenchymal stem cells (BMSCs), derived from TIONFH rabbits, were used for in vitro experiments. Cell viability was determined using the MTT assay. RESULTS: High expression of miR-320a inhibited the osteogenic differentiation capacity of BMSCs in vitro by inhibiting the expression of the osteoblastic differentiation markers ALP and RUNX2. MiR-320a inhibitor-loaded PEG-PLGA-PLL nanoparticles were constructed with a mean loading efficiency of 1.414 ± 0.160%, and a mean encapsulation efficiency of 93.45 ± 1.24%, which released 50% of the loaded miR-320a inhibitor at day 12 and 80% on day 18. Then, inhibitor release entered the plateau. After treatment with the miR-320a inhibitor nanoparticle, the empty lacunae were decreased in the femoral head tissue of TIONFH rabbits, and the osteoblast surface/bone surface (Ob.S/BS), osteoblast number/bone perimeter (Ob.N/B.Pm), bone volume fraction, and bone mineral density increased. Additionally, the expression of osteogenic markers RUNX2 and ALP was significantly elevated in the TIONFH rabbit model. CONCLUSION: The miR-320a inhibitor-loaded PEG-PLGA-PLL nanoparticle sustained drug release system significantly contributed to bone regeneration in the TIONFH rabbit model, which might be a promising strategy for the treatment of TIONFH.

SOCS1, the feedback regulator of STAT1/3, inhibits the osteogenic differentiation of rat bone marrow mesenchymal stem cells.

Our study showed that Signal transducer and activator of transcription (STAT)1 and STAT3 phosphorylation was firstly upregulated in the early stage of osteogenic differentiation (OD), and quickly eliminated in hours. Following with phosphorylation of STAT1/3, its downstream feedback regulator Suppressor of cytokine signaling 1 (SOCS1) protein also underwent a quick elevation. Further activation and deactivation of STAT1/3, by administrated with Colivelin and Nifuroxazide in Bone mesenchymal stem cells (BMSCs), increased and decreased SOCS1 expression, inhibited and promoted OD of BMSCs, respectively, as evidenced by Alizarin staining, alkaline phosphatase (ALP) activity, and determination of Run-related transcription factor 2 (RUNX2), Osteocalcin (OCN), ALP, and Bone sialoprotein (BSP). In addition, administration of Colivelin and Nifuroxazide caused and blocked inflammation and apoptosis of BMSCs. To further elucidate the role of STAT1/3-SOCS1 regulatory loop on OD of BMSCs, we overexpressed or silenced SOCS1 in BMSCs during OD. WB data showed that overexpression of SOCS1 repressed STAT1/3 phosphorylation, and knockdown of SOCS1 increased the phosphorylated STAT1/3. Further mechanism study showed that OD of BMSCs was elevated or reduced by SOCS1 overexpression or knockdown, respectively. The findings presenting indicated that the STAT1/3-SOCS1 axis may be exploited as an innovative strategy to enhance osteogenesis in regenerative medicine.

CircTYW1 serves as a sponge for microRNA-380 in accelerating neurological recovery following spinal cord injury via regulating FGF9.

As one of the most severe kinds of neurological damage, spinal cord injury (SCI) contributes to persistent motor dysfunction and involves a large repertoire of gene alterations. The participation of circular RNAs (circRNAs) in neurological recovery following SCI needs to be clarified. In the current work, we attempted to assess the function of hsa_circRNA_0003962/circTYW1 and its underlying mechanism in SCI. By accessing the GEO repository, the expression of circTYW1, microRNA-380 (miR-380), and FGF9 in SCI and sham-operated rats was evaluated. PC12 cells after oxygen-glucose deprivation (OGD) treatment were prepared to mimic the SCI model. circTYW1 and FGF9 were poorly expressed, whereas miR-380 was highly expressed in the spinal cord tissues of SCI rats. circTYW1 promoted neurological recovery in SCI rats and inhibited apoptosis in spinal cord tissues. In PC12 cells exposed to OGD, circTYW1 suppressed PC12 cell apoptosis; however, miR-380 overexpression reversed the protective effect of circTYW1 on PC12 cells. Also, circTYW1 promoted FGF9 expression through competitively binding to miR-380, which activated the ERK1/2 signaling. In summary, our results demonstrated that declines in circTYW1 prevented SCI rats from neurological recovery by regulating the miR-380/FGF9/ERK1/2 axis, which might provide new understanding for SCI treatment.

microRNA-935-modified bone marrow mesenchymal stem cells-derived exosomes enhance osteoblast proliferation and differentiation in osteoporotic rats.

AIMS: The involvement of several microRNAs (miRNAs) in osteogenic differentiation has been indicated recently. Also, exosomes, derived from different cells, could shuttle specific miRNAs to other cell systems. Nevertheless, the effect and mechanism of microRNA-935 (miR-935)-containing exosomes in osteoblasts remain basically unclear. The current work was set to inspect the relevance of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes (BMSC-exo) carrying miR-935 to osteoporotic rats. METHODS: The extracted BMSCs and purchased osteoblasts were cultured, followed by exosome isolation and identification. After cell grouping, osteoblasts were co-cultured with BMSCs. CCK-8, alizarin red staining as well as ALP staining were performed to detect osteoblast proliferation and activity. The binding connection between miR-935 and signal transducer and activator of transcription 1 (STAT1) was measured by dual-luciferase reporter gene assays. The expression profiles of miR-935, STAT1 and osteoblast-related proteins were assessed by RT-qPCR and Western blot. A rat model with osteoporosis was induced, and the BMD, BV/TV, Tb.N, Tb.Th and Tb.Sp values in rat bone tissues were observed by Micro-CT. RESULTS: BMSC-exo inhibited STAT1 levels by the delivery of miR-935 into osteoblasts, while STAT1 silencing promoted ALP activity in osteoblasts and mineralized nodules. STAT1 was identified as a target gene of miR-935. Moreover, in vivo experiments showed that in ovariectomized rats, silencing of miR-935 significantly reduced BMD, BV/TV, Tb.N, Tb.Th and increased Tb.Sp. CONCLUSION: BMSC-exo carry miR-935 to promote osteoblast proliferation and differentiation through targeting STAT1.

PSMC6 promotes osteoblast apoptosis through inhibiting PI3K/AKT signaling pathway activation in ovariectomy-induced osteoporosis mouse model.

There is now increasing evidence which suggests a key role for osteoblast apoptosis in the pathogenesis of postmenopausal osteoporosis. Here, we evaluated the role and mechanism of proteasome 26S subunit, ATPase (PSMC) 6, a protein that is highly expressed in bone. Gene expression pattern had been extracted based on database of Gene Expression Omnibus (GEO). GEO2R was employed for analyses, while the DAVID database was adopted to further analyze the gene ontology (GO) as well as Kyoto Encyclopedia of Genomes pathway (KEGG) enrichment. Then, the Search Tool Retrieval of Interacting Genes (STRING) was utilized to carry out interaction regulatory network for the top 200 differentially expressed genes (DEGs). A key gene, called PSMC6, was identified by Cytoscape 3.6.0. The OVX osteoporosis model was established in female C57BL/6 mice by full bilateral ovariectomy. According to our findings, PSMC6 gene knockout would elevate bone mineral density (BMD) and the phosphorylation level of PI3K protein and increased the protein level of cleaved caspase-3/-9 in OVX osteoporosis mice. Further, MTT, bromodeoxyuridine, and flow cytometry assays revealed that PSMC6 inhibition promoted the progression of cell cycle and cell proliferation, whereas, PSMC6 overexpression promoted the apoptosis and inhibited cell cycle progression and cell proliferation in vitro. Besides, we found that PI3K activation significantly decreased PSMC6-induced osteoblast apoptosis and promoted cell proliferation through regulating the protein levels of p53, cyclinD1, and cleaved caspase-3/9. In conclusion, PSMC6 aggravated the degree of OVX-induced osteoporosis by inhibiting the PI3K/AKT signal transduction pathway, thereby promoting the apoptosis of osteoblasts.

LncRNA NKILA integrates RXFP1/AKT and NF-κB signalling to regulate osteogenesis of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are previously found to have potential capacity to differentiate into osteocytes when exposed to specific stimuli. However, the detailed molecular mechanism during this progress remains largely unknown. In the current study, we characterized the lncRNA NKILA as a crucial positive regulator for osteogenesis of MSCs. NKILA attenuation significantly inhibits the calcium deposition and alkaline phosphatase activity of MSCs. More interestingly, we defined that NKILA is functionally involved in the regulation of RXFP1/PI3K-AKT and NF-κB signalling. Knockdown of NKILA dramatically down-regulates the expression of RXFP1 and then reduces the activity of AKT, a downstream regulator of RXFP1 signalling which is widely accepted as an activator of osteogenesis. Moreover, we identify NF-κB as another critical regulator implicated in NKILA-mediated osteogenic differentiation. Inhibition of NF-κB can induce the expression of RUNX2, a master transcription factor of osteogenesis, in a HDAC2-mediated deacetylation manner. Thus, this study illustrates the regulatory function of NKILA in osteogenesis through distinct signalling pathways, therefore providing a new insight into searching for new molecular targets for bone tissue repair and regeneration.

MicroRNA-181a exerts anti-inflammatory effects via inhibition of the ERK pathway in mice with intervertebral disc degeneration.

Enzymatic decomposition of extracellular matrix and possibly local inflammation may cause intervertebral disc degeneration (IDD). MicroRNAs have been reported to correlate with the development of IDD. In this experiment, we aim at finding out the role of miR-181a in the inflammation of IDD and the underlying mechanism. The targeting relationship between miR-181a and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was verified. Following the establishment of IDD mouse models, disc height index (DHI) and the change of DHI (%DHI) were measured. The functional role of miR-181a in IDD was determined using ectopic expression and depletion and reporter assay experiments. Expression of miR-181a, TRAIL, extracellular signal-regulated kinase (ERK) pathway-related genes and inflammatory factors was evaluated. Also, the expression of collagen I and collagen II was observed. miR-181a directly targeted TRAIL. IDD mice exhibited significant degeneration of the intervertebral disc. miR-181a was downregulated while TRAIL was upregulated in mice with IDD. miR-181a upregulation and the ERK pathway inhibition could reduce expression of TRAIL, ERK pathway-related genes, inflammatory factors, and collagen I, but promote collagen II expression. Our results reveal that upregulation of miR-181a protects against inflammatory response by inactivating the ERK pathway via suppression of TRAIL in IDD mice. These results point to miR-181a as a potential therapeutic target for the clinical management of IDD.

ELK1-induced upregulation of long non-coding RNA MIR100HG predicts poor prognosis and promotes the progression of osteosarcoma by epigenetically silencing LATS1 and LATS2.

Osteosarcoma (OS) is the commonest malignant bone tumor in the world. High incidence of OS has gradually become a social problem. Recent years, numerous studies have revealed that long non-coding RNAs (lncRNAs) are crucial regulators in the tumor progression. As a member of lncRNA family, MIR100HG has been reported to be an oncogene in breast cancer and acute megakaryoblastic leukemia. Nevertheless, the specific role of MIR100HG in osteosarcoma is still unclear. In this study, we investigated the biological function and molecular mechanism of MIR100HG in the progression of osteosarcoma. At first, we measured the high expression of MIR100HG in OS tissues and cell lines by qRT-PCR. Kaplan-Meier method revealed that high expression of MIR100HG is a factor for the poor prognosis of OS patients (P = 0.004). To explore the effect of MIR100HG on the biological processes of OS, loss-of-function assays were conducted in OS cells. Functionally, MIR100HG knockdown suppressed cell proliferation, cell cycle progression while promoted cell apoptosis. Mechanistically, MIR100HG was upregulated by the transcription factor ELK1. The upregulation of MIR100HG led to the inactivation of Hippo pathway. Furthermore, we found that MIR100HG inactivated Hippo pathway in OS cells by epigenetically silencing LATS1 and LATS2. Rescue assays demonstrated that LATS1/2 involved in MIR100HG-mediated OS progression. In summary, our study indicated that ELK1-induced upregulation of MIR100HG promoted OS progression by epigenetically silencing LATS1 and LATS2 and inactivating Hippo pathway.