The bone-liver interaction modulates immune and hematopoietic function through Pinch-Cxcl12-Mbl2 pathway.

Mesenchymal stromal cells (MSCs) are used to treat infectious and immune diseases and disorders; however, its mechanism(s) remain incompletely defined. Here we find that bone marrow stromal cells (BMSCs) lacking Pinch1/2 proteins display dramatically reduced ability to suppress lipopolysaccharide (LPS)-induced acute lung injury and dextran sulfate sodium (DSS)-induced inflammatory bowel disease in mice. Prx1-Cre; Pinch1f/f; Pinch2-/- transgenic mice have severe defects in both immune and hematopoietic functions, resulting in premature death, which can be restored by intravenous injection of wild-type BMSCs. Single cell sequencing analyses reveal dramatic alterations in subpopulations of the BMSCs in Pinch mutant mice. Pinch loss in Prx1+ cells blocks differentiation and maturation of hematopoietic cells in the bone marrow and increases production of pro-inflammatory cytokines TNF-α and IL-1ß in monocytes. We find that Pinch is critical for expression of Cxcl12 in BMSCs; reduced production of Cxcl12 protein from Pinch-deficient BMSCs reduces expression of the Mbl2 complement in hepatocytes, thus impairing the innate immunity and thereby contributing to infection and death. Administration of recombinant Mbl2 protein restores the lethality induced by Pinch loss in mice. Collectively, we demonstrate that the novel Pinch-Cxcl12-Mbl2 signaling pathway promotes the interactions between bone and liver to modulate immunity and hematopoiesis and may provide a useful therapeutic target for immune and infectious diseases.

Histone H3K9 demethylase JMJD2B/KDM4B promotes osteogenic differentiation of bone marrow-derived mesenchymal stem cells by regulating H3K9me2 on RUNX2.

Background: A variety of proteins including epigenetic factors are involved in the differentiation of human bone marrow mesenchymal stem cells. These cells also exhibited an epigenetic plasticity that enabled them to trans-differentiate from adipocytes to osteoblasts (and vice versa) after commitment. Further in-depth study of their epigenetic alterations may make sense. Methods: Chromatin Immunoprecipitation-PCR (ChIP-PCR) was used to detect the methylation enrichment status of H3K9me2 in the Runx2 promoter, alizarin red and alkaline phosphatase (ALP) staining were used to detect osteogenic differentiation and mineralization ability, western blot and quantitative RT-PCR were used to measure the differential expression of osteogenesis-related proteins and genes. Recombinant Lentivirus mediated gain-of-function and loss-of-function study. The scale of epigenetic modification was detected by laser confocal. Results: Our results showed that compared with human bone marrow mesenchymal stem cells (hBMSCs) without osteogenic differentiation treatment, hBMSCs after osteogenic differentiation significantly promoted osteogenic differentiation and mRNA expression such as JMJD2B/KDM4B, osteogenesis-related genes like Runx2 and FAM210A in hBMSCs cells, suggesting that upregulation of JMJD2B/KDM4B is involved in the promoting effect of osteogenesis. After overexpression and silencing expression of JMJD2B, we found a completely opposite and significant difference in mRNA expression of osteogenesis-related genes and staining in hBMSCs. Overexpression of JMJD2B/KDM4B significantly promoted osteogenic differentiation, suggesting that JMJD2B/KDM4B could promote osteogenesis. In addition, ChIP-PCR showed that overexpression of JMJD2B/KDM4B significantly reversed the methylation enrichment status of H3K9me2 in Runx2 promoter. Furthermore, overexpression of JMJD2B/KDM4B significantly reverses the inhibitory effect of BIX01294 on H3K9me2, suggesting that JMJD2B/KDM4B regulates the osteogenic differentiation of hBMSCs by changing the methylation status of H3K9me2 at the Runx2 promoter. Conclusions: Taken together, these results suggest that JMJD2B/ KDM4B may induce the osteogenic differentiation of hBMSCs by regulating the methylation level of H3K9me2 at the Runx2 promoter.

A Network Pharmacology and Molecular Docking Strategy to Explore Potential Targets and Mechanisms Underlying the Effect of Curcumin on Osteonecrosis of the Femoral Head in Systemic Lupus Erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is a refractory immune disease, which is often complicated with osteonecrosis of the femoral head (ONFH). Curcumin, the most active ingredient of Curcuma longa with a variety of biological activities, has wide effects on the body system. The study is aimed at exploring the potential therapeutic targets underlying the effect of curcumin on SLE-ONFH by utilizing a network pharmacology approach and molecular docking strategy. METHODS: Curcumin and its drug targets were identified using network analysis. First, the Swiss target prediction, GeneCards, and OMIM databases were mined for information relevant to the prediction of curcumin targets and SLE-ONFH-related targets. Second, the curcumin target gene, SLE-ONFH shared gene, and curcumin-SLE-ONFH target gene networks were created in Cytoscape software followed by collecting the candidate targets of each component by R software. Third, the targets and enriched pathways were examined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Eventually, a gene-pathway network was constructed and visualized by Cytoscape software; key potential central targets were verified and checked by molecular docking and literature review. RESULTS: 201 potential targets of curcumin and 170 related targets involved in SLE-ONFH were subjected to network analysis, and the 36 intersection targets indicated the potential targets of curcumin for the treatment of SLE-ONFH. Additionally, for getting more comprehensive and accurate candidate genes, the 36 potential targets were determined to be analyzed by network topology and 285 candidate genes were obtained finally. The top 20 biological processes, cellular components, and molecular functions were identified, when corrected by a P value ≤ 0.05. 20 related signaling pathways were identified by KEGG analysis, when corrected according to a Bonferroni P value ≤ 0.05. Molecular docking showed that the top three genes (TP53, IL6, VEGFA) have good binding force with curcumin; combined with literature review, some other genes such as TNF, CCND1, CASP3, and MMP9 were also identified. CONCLUSION: The present study explored the potential targets and signaling pathways of curcumin against SLE-ONFH, which could provide a better understanding of its effects in terms of regulating cell cycle, angiogenesis, immunosuppression, inflammation, and bone destruction.

Silencing of MEF2D by siRNA Loaded Selenium Nanoparticles for Ovarian Cancer Therapy.

BACKGROUND: Delivery of therapeutic small interfering RNA (siRNA) via functionalized nanoparticles holds great promise for cancer therapy. However, developing a safe and efficient delivery carrier of siRNA is a challenging issue. METHODS: RGDfC peptide was used to modify the surface of selenium nanoparticles (SeNPs) to synthesize a biocompatible siRNA delivery vehicle (R-SeNPs), and MEF2D-siRNA was loaded onto R-SeNPs to prepare a functionalized selenium nanoparticle R-Se@MEF2D-siRNA. The chemical properties of R-SeNPs were characterized, and the anticancer efficacy as well as related mechanisms of R-Se@MEF2D-siRNA were further explored. RESULTS: R-Se@MEF2D-siRNA was significantly taken up by SKOV3 cells and could enter SKOV3 cells mainly in the clathrin-associated endocytosis way. The result of in vitro siRNA release demonstrated that R-Se@MEF2D-siRNA could release MEF2D-siRNA quicker in a microenvironment simulating a lysosomal environment in tumor cells compared to a normal physiological environment. The results of qRT-PCR assay proved that R-Se@MEF2D-siRNA could effectively silence the expression of the MEF2D gene in SKOV3 cells. R-Se@MEF2D-siRNA remarkably suppressed the proliferation of SKOV3 cells and further triggered its apoptosis. In addition, R-Se@MEF2D-siRNA had the capability to disrupt mitochondrial membrane potential (MMP) in SKOV3 cells and resulted in the overproduction of reactive oxygen species (ROS), indicating that mitochondrial dysfunction and ROS generation played an important role in the apoptosis of SKOV3 cells induced by R-Se@MEF2D-siRNA. In vivo, R-Se@MEF2D-siRNA also exhibited excellent antitumor activity mainly through decreasing tumor cells proliferation and triggering their apoptosis in tumor-bearing nude mice. CONCLUSION: R-Se@MEF2D-siRNA provides an alternative strategy for ovarian cancer treatment in the clinic.

Lysine-Specific Demethylase 4A Regulates Osteogenic Differentiation via Regulating the Binding Ability of H3K9me3 with the Promoters of Runx2, Osterix and Osteocalcin.

A well-studied subject of epigenetics, the histone methylation located at lysine and arginine is overseen via methyltransferases and demethylases. Lysine-specific demethylase 4A (KDM4A) comprises a lysine demethylase and possesses specificity for H3K9me3 and H3K36me3, which is capable of being used in order to activate histone transcription. Our team examined the expression of KDM4A within Sprague Dawley (SD) rats and further investigated the mechanism via which this phenomena regulates osteogenic variation within the present study. The overexpression of KDM4A facilitated the process of osteoblast differentiation in bone mesenchymal stem cells (BMSC), while the knocking down differentiation via osteoblast was restrained via the suppression of the expression of Runx2, Osterix, alkaline phosphatase (ALP), and osteocalcin (OCN). Knocking down KDM4A lowered levels of the promoter expression of Runx2, osterix, and OCN, and raised levels of H3K27me3 expression. The results demonstrated that KDM4A possesses a crucial role within the differentiation of osteoblasts and furthermore regulates the expression of Runx2, Osterix, and OCN via H3K9me3. The present research may provide new insights into the treatment of bone healing.

lncRNA GAS8-AS1 downregulates lncRNA UCA1 to inhibit osteosarcoma cell migration and invasion.

BACKGROUND: Osteosarcoma (OS) is the most common type of primary bone tumor that mainly affects adolescents and young adults. The present study explored the role of lncRNA GAS8-AS1 in OS. METHODS: A total of 48 OS patients were selected from the 82 OS patients admitted by Luoyang Orthopedic Hospital of Henan Province between May 2010 and May 2013. Transient cell transfections, Transwell cell migration and invasion assay, RT-qPCR, and patient follow-up were carried out during the research. RESULTS: The results showed that GAS8-AS1 was downregulated, while UCA1 was upregulate in cancer tissues in comparison to adjacent non-cancer tissues of OS patients. GAS8-AS1 was not affected by clinical stage. Follow-up study showed that downregulated GAS8-AS1 in cancer tissues was closely correlated with poor survival. GAS8-AS1 and UCA1 were inversely correlated in cancer tissues. Overexpression of UCA1 failed to affect the expression of GAS8-AS1, while overexpression of GAS8-AS1 led to downregulated expression of UCA1 in OS cells, while the molecular mediators between these two lncRNAs are unknown. Overexpression of GAS8-AS1 did not affect OS cell proliferation but significantly inhibited cancer cell migration and invasion. Overexpression of UCA1 promoted the migration and invasion of OS cells and attenuated the effects of overexpressing GAS8-AS1. CONCLUSIONS: Therefore, GAS8-AS1 may inhibit OS cell migration and invasion by downregulating oncogenic UCA1.

The protective effects of bexarotene against advanced glycation end-product (AGE)-induced degradation of articular extracellular matrix (ECM).

Osteoarthritis (OA) is a common debilitating disease primarily characterised by excessive loss of the articular ECM, which is composed of up to 95% type II collagen. Among the factors that contribute to the pathogenesis of OA, the natural process of aging is regarded as the most significant risk factor. AGEs, which are extremely resilient to degradation, are produced in the body naturally as a result of the Maillard process of nonenzymatic glycation and are also introduced through diet and tobacco smoke. AGEs have a high affinity for collagen and therefore accumulate in joint tissues, where they induce increased expression of proinflammatory cytokines, chemokines, and degradative enzymes. Additionally, AGEs induce oxidative stress, which further exacerbates the degradative process. Type II collagen is targeted for degradation by matrix metalloproteinases (MMPs), particularly MMP-3 and MMP-13, and AGEs have been shown to trigger increased expression of these MMPs. The role of retinoid and rexinoid receptors as specific treatment targets has been receiving increasing attention. Bexarotene is a retinoid X receptor (RXR) agonist used for the treatment of T-cell lymphoma and other cancers which has displayed a favourable safety profile. Here, we examined the roles of RXR agonism using bexarotene on AGE-induced markers of OA, including oxidative stress, inflammatory response, and MMP-mediated degradation of type II collagen. Furthermore, we demonstrate that bexarotene inhibited phosphorylation of IκBα, thereby suppressing activation of the proinflammatory NF-κB cellular signalling pathway. These findings present a basis for selective targeting of RXR by bexarotene as a potential treatment of OA induced by AGEs.

Activation of GPER suppresses the malignancy of osteosarcoma cells via down regulation of IL-6 and IL-8.

Estrogenic signals can regulate the progression of osteosarcoma (OS) via classic estrogen receptor α/ß (ERα/ß). G protein-coupled estrogen receptor (GPER) can mediate the non-genomic effects of estrogen and regulate the progression of various cancers. Our present study revealed that the expression of GPER in OS cells and tissues was lower than that in their corresponding controls. Activation of GPER via its specific agonist G-1 can decrease the proliferation, migration, and invasion of OS cells. By screening the expression of cytokines involved in the progression of OS, we found that activation of GPER can inhibit the expression of interleukin-6 (IL-6) and IL-8 in OS cells. Recombinant IL-6 (rIL-6) or rIL-8 can attenuate G-1 suppressed migration of OS cells. Mechanically, activation of GPER can rapidly decease the phosphorylation and nuclear translocation of NF-κB in OS cells. While over expression of p65 significantly attenuated G-1 induced down regulation of IL-6/IL-8. Further, G-1 can decrease the activation of p38-MAPK, which can further shorten the half-life of IL-8 mRNA. Collectively, we revealed that GPER can suppress the migration and invasion of OS cells via inhibition of IL-6 and IL-8. It suggested that GPER might be a potential therapy target for OS treatment.

[EFFECTIVENESS OF UC ULTRA-CONGRUENT ROTATING PLATFORM PROSTHESIS IN TREATMENT OF KNEE OSTEOARTHRITIS].

OBJECTIVE: To explore the effectiveness of UC ultra-congruent rotating platform prosthesis in the treatment of knee osteoarthritis by comparing with fixed-bearing implant. METHODS: The clinical data were retrospectively analyzed, from 98 patients (98 knees) with knee osteoarthritis undergoing primary total knee arthroplasty between January 2011 and December 2012. The UC ultra-congruent rotating platform prosthesis was used in 56 cases (mobile-bearing group) and fixed-bearing implant was used in 42 cases (fixed-bearing group). There was no significant difference in gender, age, side, weight, disease duration, grading of arthritis, the number of varus and valgus malformation, preoperative range of motion of the knee, the Knee Society Score (KSS) score, the visual analogue scale (VAS) score, femorotibial angle, tibial angle, and articular surface angle between 2 groups (P > 0.05). The operation time (including anesthetic time), intraoperative blood loss, hospitalization time, total hospitalization expenses, postoperative range of motion of the knee, the KSS score, and the VAS score were compared. The femorotibial angle, tibial angle, and articular surface angle were measured on the basis of anteroposterior and lateral X-ray films, and prosthesis loosening was observed. RESULTS: There was no significant difference in the operation time, intraoperative blood loss, and hospitalization time between 2 groups (P > 0.05), while the total hospitalization expenses of fixed-bearing group were significantly lower than those of the mobile-bearing group (t = 8.506, P = 0.000). The patients were followed up 16-30 months in the mobile-bearing group, and for 16-38 months in the fixed-bearing group. Postoperative complications occurred in 3 cases (7.14%) of the fixed-bearing group (1 case of fat liquefaction of incision, 1 case of joint stiff, and 1 case of anterior knee pain), and in 3 cases (5.36%) of the mobile-bearing group (1 case of delayed wound healing, and 2 cases of anterior knee pain); there was no significant difference in the complication rate between 2 groups (χ2 = 0.133, P = 0.516). At last follow-up, the KSS score, VAS score, range of motion of the knee, femorotibial angle, tibial angle, and articular surface angle were superior significantly to those before operation in both groups (P < 0.05), but no significant difference was found between 2 groups (P > 0.05). No radiographic signs of radiolucent line, prosthetic dislocation, patellar dislocation, prosthetic loosening, and fracture was found. CONCLUSION: UC ultra-congruent rotating platform prosthesis in the treatment of knee osteoarthritis can effectively improve the knee joint function and relief pain, which has the same short-term effectiveness in fixed bearing implant.